The scientific rationale and development of an optimized dentifrice for the treatment of dentin hypersensitivity.

PubMed

Tavss, Edward A; Fisher, Steven W; Campbell, Shannon; Bonta, Yolanda; Darcy-Siegel, Joann; Blackwell, Bernie L; Volpe, Anthony R; Miller, Steven E

2004-02-01

To describe the development of a new dentin hypersensitivity treatment, Colgate Sensitive Maximum Strength dentifrice, containing 5% potassium nitrate as the anti-hypersensitivity active agent. The objective was to develop a home-use hypersensitivity dentifrice that would be superior to the market leader, improving on what is available, which also contains 5% potassium nitrate as the anti-hypersensitivity active agent. In vivo (clinicals, taste evaluation and rat caries), in vitro (potassium flux) and analytical (rheology, dispensed volume, scanning electron microscopy, electron scanning chemical analysis and radioactive dentin abrasion) methods were performed. The objective was accomplished with the development of a new activated silica technology that resulted in enhanced potassium ion activity. In vitro documentation, supported by clinical studies, demonstrated that the resulting formula is more effective than the market leader for relief of hypersensitivity pain. Fast pain relief in less than 2 weeks and long-lasting protection against pain with regular use have also been clinically documented. Furthermore, FDA-required in vivo and in vitro studies indicate that this formula, which contains 0.45% stannous fluoride (1100 ppm fluoride) as the anti-caries active agent, is effective against caries. Good taste, acceptable rheology, acceptable abrasivity, and cosmetic and chemical stability have all been engineered into this unique dentin hypersensitivity treatment. In summary, a highly efficacious consumer friendly treatment for dentin hypersensitivity has been developed.

Dentinal tubule occluding capability of nano-hydroxyapatite; The in-vitro evaluation.

PubMed

Baglar, Serdar; Erdem, Umit; Dogan, Mustafa; Turkoz, Mustafa

2018-04-29

In this in-vitro study, the effectiveness of experimental pure nano-hydroxyapatite (nHAP) and 1%, 2%, and 3% F¯ doped nano-HAp on dentine tubule occlusion was investigated. And also, the cytotoxicity of materials used in the experiment was evaluated. Nano-HAp types were synthesized by the precipitation method. Forty dentin specimens were randomly divided into five groups of; 1-no treatment (control), 2-specimens treated with 10% pure nano-HAp and 3, 4, 5 specimens treated with 1%, 2%, and 3% F - doped 10% nano-HAp, respectively. To evaluate the effectiveness of the materials used; pH, FTIR, and scanning electron microscopy evaluations were performed before and after degredation in simulated body fluid. To determine cytotoxicity of the materials, MTT assay was performed. Statistical evaluations were performed with F and t tests. All of the nano-HAp materials used in this study built up an effective covering layer on the dentin surfaces even with plugs in tubules. It was found that this layer had also a resistance to degradation. None of the evaluated nano-HAp types were have toxicity. Fluoride doping showed a positive effect on physical and chemical stability until a critical value of 1% F - . The all evaluated nano-HAp types may be effectively used in dentin hypersensitivity treatment. The formed nano-HAp layers were seem to resistant to hydrolic deletion. The pure and 1% F - doped nano-HAp showed the highest biocompatibility thus it was assessed that pure and 1% F - doped materials may be used as an active ingredient in dentin hypersensitivity agents. © 2018 Wiley Periodicals, Inc.

A comparison of dentifrices for clinical relief from dentin hypersensitivity using the Jay Sensitivity Sensor Probe.

PubMed

Hegde, Shashikanth; Rao, B H Sripathi; Kakar, Ravish Chander; Kakar, Ashish

2013-05-01

To evaluate the clinical relief from dentin hypersensitivity among subjects provided with a dentifrice formulated with 8% arginine, calcium carbonate and 1,000 ppm fluoride [sodium monofluorophosphate (MFP)] in comparison to those issued a commercially available dentifrice containing 1,000 ppm fluoride [as sodium monofluorophosphate (MFP)]. Clinical evaluations for hypersensitivity were performed with a novel tactile hypersensitivity measuring instrument--the Jay Sensitivity Sensor (Jay) Probe--in conjunction with evaporative triggers by air blast (Schiff scale) and Visual Analog Scores (VAS). Qualified adults from the Mangalore, India area who presented two teeth with dentin hypersensitivity were enrolled for this double-blind, randomized, parallel, controlled clinical trial conducted in an outpatient clinical setting. At baseline, dentin hypersensitivity was evaluated by the Jay Probe (tactile), air blast and VAS methods. Subjects were randomly issued a study dentifrice and instructed to brush their teeth for 1 minute twice daily with the provided dentifrice. Clinical evaluations for hypersensitivity were repeated after 2, 4 and 8 weeks of product use. 86 subjects (35 males and 51 females) complied with the study protocol and completed the entire study. At each recall visit, both treatment groups demonstrated significant reductions in dentin hypersensitivity from their corresponding baselines (P < 0.05). Subjects assigned the 8% arginine, calcium carbonate and 1,000 ppm fluoride dentifrice demonstrated statistically significant reductions in responses to tactile stimuli, air blast, and VAS responses in comparison to those using the dentifrice containing 1,000 ppm fluoride after 2, 4, and 8 weeks, respectively.

In Vitro Study of Dentin Hypersensitivity Treated by 980-nm Diode Laser.

PubMed

Liu, Ying; Gao, Jie; Gao, Yan; Xu, Shuaimei; Zhan, Xueling; Wu, Buling

2013-01-01

To investigate the ultrastructural changes of dentin irradiated with 980-nm diode laser under different parameters and to observe the morphological alterations of odontoblasts and pulp tissue to determine the safety parameters of 980-nm diode laser in the treatment of dentin hypersensitivity (DH). Twenty extracted human third molars were selected to prepare dentin discs. Each dentin disc was divided into four areas and was irradiated by 980-nm diode laser under different parameters: Group A: control group, 0 J/cm(2); Group B: 2 W/CW (continuous mode), 166 J/cm(2); Group C: 3W/CW, 250 J/cm(2); and Group D: 4W/CW, 333 J/cm(2). Ten additional extracted human third molars were selected to prepare dentin discs. Each dentin disc was divided into two areas and was irradiated by 980-nm diode laser: Group E: control group, 0 J/cm(2); and Group F: 2.0 W/CW, 166 J/cm(2). The morphological alterations of the dentin surfaces and odontoblasts were examined with scanning electron microscopy (SEM), and the morphological alterations of the dental pulp tissue irradiated by laser were observed with an upright microscope. The study demonstrated that dentinal tubules can be entirely blocked after irradiation by 980-nm diode laser, regardless of the parameter setting. Diode laser with settings of 2.0 W and 980-nm sealed exposed dentin tubules effectively, and no significant morphological alterations of the pulp and odontoblasts were observed after irradiation. Irradiation with 980-nm diode laser could be effective for routine clinical treatment of DH, and 2.0W/CW (166 J/cm(2)) was a suitable energy parameter due to its rapid sealing of the exposed dentin tubules and its safety to the odontoblasts and pulp tissue.

In Vitro Study of Dentin Hypersensitivity Treated by 980-nm Diode Laser

PubMed Central

Liu, Ying; Gao, Jie; Gao, Yan; XU, Shuaimei; Zhan, Xueling; Wu, Buling

2013-01-01

Introduction: To investigate the ultrastructural changes of dentin irradiated with 980-nm diode laser under different parameters and to observe the morphological alterations of odontoblasts and pulp tissue to determine the safety parameters of 980-nm diode laser in the treatment of dentin hypersensitivity (DH). Methods: Twenty extracted human third molars were selected to prepare dentin discs. Each dentin disc was divided into four areas and was irradiated by 980-nm diode laser under different parameters: Group A: control group, 0 J/cm2; Group B: 2 W/CW (continuous mode), 166 J/cm2; Group C: 3W/CW, 250 J/cm2; and Group D: 4W/CW, 333 J/cm2. Ten additional extracted human third molars were selected to prepare dentin discs. Each dentin disc was divided into two areas and was irradiated by 980-nm diode laser: Group E: control group, 0 J/cm2; and Group F: 2.0 W/CW, 166 J/cm2. The morphological alterations of the dentin surfaces and odontoblasts were examined with scanning electron microscopy (SEM), and the morphological alterations of the dental pulp tissue irradiated by laser were observed with an upright microscope. Results: The study demonstrated that dentinal tubules can be entirely blocked after irradiation by 980-nm diode laser, regardless of the parameter setting. Diode laser with settings of 2.0 W and 980-nm sealed exposed dentin tubules effectively, and no significant morphological alterations of the pulp and odontoblasts were observed after irradiation. Conclusions: Irradiation with 980-nm diode laser could be effective for routine clinical treatment of DH, and 2.0W/CW (166 J/cm2) was a suitable energy parameter due to its rapid sealing of the exposed dentin tubules and its safety to the odontoblasts and pulp tissue. PMID:25606318

Effect and Stability of Poly(Amido Amine)-Induced Biomineralization on Dentinal Tubule Occlusion

PubMed Central

Gao, Yuan; Liang, Kunneng; Li, Jianshu; Yuan, He; Liu, Hongling; Duan, Xiaolei; Li, Jiyao

2017-01-01

In recent years, scientists have developed various biomaterials to remineralize human teeth to treat dentine hypersensitivity. Poly(amido amine) (PAMAM) dendrimers have become a research focus in this field. It has been demonstrated that PAMAM is able to create precipitates both on the surface of and within the dentinal tubules, however, there is little information about its effect on reducing dentine permeability in vitro. This study aimed to evaluate the in vitro effectiveness and stability of the fourth generation amine-terminated PAMAM on dentinal tubule occlusion, especially on dentine permeability. Sodium fluoride (NaF), which has been widely used as a desensitizing agent, is regarded as positive control. Demineralized sensitive dentine samples were coated with PAMAM or sodium fluoride solutions and soaked in artificial saliva (AS) at 37 °C for different periods. Four weeks later, samples in each group were then equally split into two subgroups for testing using a brushing challenge and an acid challenge. Dentine permeability of each specimen was measured before and after each challenge using a fluid filtration system. Dentine morphology and surface deposits were characterized by scanning electron microscope (SEM) and analyzed with Image-Pro Plus software. Data were evaluated through multifactorial ANOVA with repeated measures and pair-wise comparisons at a level of 5%. The results showed that PAMAM and NaF significantly reduced dentine permeability to 25.1% and 20.7%. Both of them created precipitates on dentine surfaces after AS immersion for 28 days. PAMAM-induced biomineralization not only on dentine surfaces, but also deeper in dentinal tubules, significantly reduced dentine permeability. Moreover, PAMAM-induced biomineralization elicited excellent stable occlusion effects after acid challenge. In conclusion, PAMAM demonstrated a strong ability to resist acid and showed great potential to be used in the treatment of dentine hypersensitivity in future. PMID:28772744

The durability of phosphoric acid promoted bioglass-dentin interaction layer.

PubMed

Bakry, A S; Takahashi, H; Otsuki, M; Tagami, J

2013-04-01

Phosphoric acid-Bioglass 45S5 paste can create an interaction layer formed of calcium-phosphate crystals on the dentin surface. In this study, the efficiency of decreasing the dentin permeability exerted by the interaction layer formed between bioglass and dentin was compared to a resin-containing oxalate desensitizing agent (MS Coat One) and a resin-free oxalate desensitizing agent (Super Seal). Dentin permeability was measured before/after a brushing abrasion challenge, followed by examining the top and the fractured dentin surfaces with a field emission scanning electron microscope. Moreover, the chemical nature of the compounds formed on top of the dentin surface was examined using the field emission scanning electron microscope (FE-SEM) equipped with an energy-dispersive X-ray spectroscope (EDS), and the crystalline structures of the dentinal surfaces were examined by X-ray diffraction (XRD). The results showed that application of 45S5 bioglass paste to dentin was able to occlude patent dentinal tubule orifices with a layer of calcium-phosphate crystals, while the oxalate containing agents were able to form small crystals which were found in dentinal tubule orifices and scattered along the superficial parts of the dentinal tubule lumen. The brushing-abrasion challenge significantly increased the permeability of dentin treated by Super Seal and MS Coat One, while these challenges had no significant effect on the dentin permeability of specimens treated with 45S5 bioglass paste. The new technique provided better durability than two products available on the market. Moreover, our previous research showed the biocompatibility of using this technique on dental pulp cells, suggesting that this technique can aid in treating dentin hypersensitivity cases. Copyright © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Cervical dentin hypersensitivity: a cross-sectional investigation in Athens, Greece.

PubMed

Rahiotis, C; Polychronopoulou, A; Tsiklakis, K; Kakaboura, A

2013-12-01

The purpose of this study was to identify the prevalence of cervical dentin hypersensitivity in a cross-sectional investigation of Greek adults. Seven hundred and sixty-seven subjects were examined. Participants were patients processed for first examination in the Clinic of Oral Diagnosis and Radiology at the Faculty of Dentistry, University of Athens. The evaluation of hypersensitivity was performed using two methods: for each tooth, the response to a) tactile stimulus and b) air-blast stimulus was measured. Additional factors such as smoking habits, oral health behaviour, consumption of acidic foods, type of toothbrush, daily use of fluoride solution and of desensitising toothpaste, gingival recession and non-carious cervical lesions were recorded and evaluated as causative factors. Descriptive statistics on the demographics of the study sample, of oral health behaviour characteristics and of oral examination findings were performed. Comparisons of these characteristics in the presence or absence of hypersensitivity were conducted with the chi-square test. Data were further analysed using multiple logistic regression modelling. Among study participants, 21·3% had at least one cervical dentin hypersensitivity reaction to the tactile stimulus, and 38·6%, to the air-blast stimulus. Multivariate analysis detected association of the hypersensitivity in tactile or air-blast stimulus with the non-carious lesions and with the gingival recessions. Additionally, a relation between hypersensitivity and air-blast stimulus with gender (female) was found. There was no association between the hypersensitivity in both of the stimuli and the level of education, smoking, consumption of acidic foods, type of toothbrush and daily use of fluoride solution or desensitising toothpaste. The overall prevalence of cervical dentin hypersensitivity in the adult population in Athens ranged from 21·3% to 38·6% depending on the type of stimuli. Cervical non-carious lesions and gingival recessions were determined as significant predictors of dentin hypersensitivity. © 2013 John Wiley & Sons Ltd.

Dentin hypersensitivity clinical study comparing LILT and LEDT keeping the same irradiation parameters

NASA Astrophysics Data System (ADS)

Lizarelli, R. F. Z.; Miguel, F. A. C.; Freitas-Pontes, K. M.; Villa, G. E. P.; Nunez, S. C.; Bagnato, V. S.

2010-11-01

Dentin hypersensitivity is a common condition associated with high dental pain. A new LED-based (light emitting diode) light source has been used as an experimental tool in some studies. Purpose: The main objective was to compare these two light sources emitting in the same spectral band (red - from 625 to 660 nm) to promote pain relief. Material and methods: A total of 6 sessions were accomplished, being three irradiation sessions and three follow-up sessions. This single-blind study compared a control group (Placebo) and two other groups with different equipments: low laser intensity treatment (LILT) and a light emitting diode system treatment (LEDT). Results: The results showed that there is no statistical difference between LILT and LEDT groups, however, both were better than control group (p <= 0.01) in terms of treatment efficiency; there is no difference between the second and the third sessions for both treatment, it means that the third session was not necessary; finally, the improvement at the end of the entire research (follow up care of 30 days) was very expressive in comparison to pre-treatment situation for all teeth (p <= 0.01). Conclusion: LILT and LEDT were equally effective to treat dentine hypersensitivity, a 3rd treatment session was not necessary/two sessions are enough.

Efficacy of Nd:YAG and GaAlAs lasers in comparison to 2% fluoride gel for the treatment of dentinal hypersensitivity.

PubMed

Soares, Marília De Lima; Porciúncula, Geane Bandeira; Lucena, Mara Ilka Holanda Medeiros De; Gueiros, Luiz Alcino Monteiro; Leão, Jair Carneiro; Carvalho, Alessandra De Albuquerque Tavares

2016-01-01

Lasers demonstrate excellent therapeutic action and are often employed in dentistry for the treatment of diverse clinical conditions. The aim of this study was to compare the efficacy of neodymium-doped yttrium-aluminum-garnet (Nd:YAG) laser, gallium-aluminum-arsenide (GaAlAs) laser, and 2% neutral fluoride gel in the treatment of dentinal hypersensitivity. Twenty-three patients were evaluated, involving a total of 48 quadrants with at least 1 tooth with dentinal hypersensitivity (89 teeth total). Pain intensity was recorded on a visual analog scale at the time of clinical examination (baseline), immediately after treatment, and 1 week posttreatment. Teeth were treated with 60 seconds of 2% neutral fluoride gel application or 60 seconds of laser treatment-Nd:YAG laser at a distance of 0.5 cm (unfocused; 1 W and 10 Hz for 60 seconds, perpendicular to the cervical surfaces) or GaAlAs laser in contact (40 mW; 4 J/cm²; spot: 0.028 cm²; 15 seconds per point on 4 points [mesial, medial, distal, and apical])-as well as sham treatments so that patients remained blind to their treatment group. All treatments provided adequate pain reduction immediately posttreatment, but laser treatments resulted in significantly greater reductions in pain intensity.

Effectiveness of various toothpastes on dentine tubule occlusion.

PubMed

Arnold, W H; Prange, M; Naumova, E A

2015-04-01

Dentine hypersensitivity is an increasing problem in dentistry. Several products are available that claim to occlude open dentine tubules and to reduce dentine hypersensitivity. The aim of this study was to investigate the effectiveness of several different products on dentine tubule occlusion using qualitative and quantitative methods. Dentine discs were prepared from extracted human premolars and molars. The dentine discs were brushed with 6 different experimental toothpastes, 1 positive control toothpaste and 1 negative control without toothpaste; the brushing simulated a total brushing time of 1 year. Half of the discs were etched with lemon juice after toothpaste application. Standardized scanning electron microphotographs were taken and converted into binary black and white images. The black pixels, which represented the open dentine tubules, were counted and statistically evaluated. Then, half of the dentine discs were broken, and the occlusion of the dentine tubules was investigated using energy dispersive X-ray spectroscopy (EDS). The number of open dentine tubules decreased significantly after brushing with 5 of the 6 tested toothpastes. A significant effect was observed after acid erosion for 3 of the 6 tested toothpastes. EDS revealed partly closed dentine tubules after brushing with 3 toothpastes; however, no partly closed dentine tubules were observed after acid erosion. Some toothpastes are capable of partial dentine tubule occlusion. This occlusion is unstable and can be removed with acid erosion. Desensitizing toothpastes are the most common products that are used against dentine hypersensitivity, and these toothpastes affect dentine tubule occlusion. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Application of Diode Laser in the Treatment of Dentine Hypersensitivity.

PubMed

Gojkov-Vukelic, Mirjana; Hadzic, Sanja; Zukanovic, Amila; Pasic, Enes; Pavlic, Veriva

2016-12-01

Dentine hypersensitivity is characterized by acute, sharp pain arising from the exposed dentine, most commonly in response to thermal, tactile, or chemical stimuli, and which cannot be linked to any other pathological changes in the tooth or the environment. Therapy uses various impregnating agents in the form of solutions or gels and, in more recent times, laser. The aim of this research was to examine the effects of treatment of hypersensitive dental cervix with diode laser. The study included 18 patients with 82 sensitive teeth. The degree of dentine hypersensitivity was evaluated by visual analogue scale (VAS), and the treatment was carried out by application of low-power diode laser over the span of three visits, which depended on the initial sensitivity. There is a significant difference in VAS values measured at the onset of treatment (baseline) and immediately after the first laser treatment (t=9.275; p=0.000), after 7 days, after the second laser treatment (14 days) (t=7.085, p=0.000), as well as after 14 days and the third laser treatment (t=5.517, p=0.000), which confirms the effectiveness of this therapeutic procedure. The results showed a reduction of hypersensitivity in response to tactile stimulus with a probe after the third treatment, even with teeth whose value on the VAS was very high at the beginning of treatment (baseline). Within the scope of the conducted study, laser therapy has provided extremely safe and effective results in the treatment of cervical dentine hypersensitivity.

Comparison of the clinical efficacy in reducing dentin hypersensitivity of a new dentifrice containing 8.0% arginine, calcium carbonate, and 1000 ppm sodium monofluorophosphate to a commercially available toothpaste containing 1000 ppm sodium monofluorophosphate: an eight-week clinical trial on adults in New Delhi, India.

PubMed

Kakar, A; Kakar, K; Sreenivasan, P K; DeVizio, W; Kohli, R

2012-01-01

This clinical study evaluated relief from dentin hypersensitivity among subjects who brushed their teeth with a new dentifrice containing 8.0% arginine, calcium carbonate, and 1000 ppm fluoride as sodium monofluorophosphate (MFP) to subjects who brushed with a commercially available dentifrice containing 1000 ppm MFP over an eight-week period. Adult subjects from the New Delhi, India area, with two teeth that exhibited dentin hypersensitivity, both to tactile stimulation using the Yeaple Probe and to stimulation using an air blast delivered by a standard dental unit syringe, were screened for study enrollment. Qualifying subjects were randomly assigned one of the study dentifrices and instructed to brush their teeth for one minute, twice daily (morning and evening) with the provided dentifrice. Follow-up examinations for dentin hypersensitivity were conducted after two, four, and eight weeks of product use. Subjects provided with the new dentifrice containing 8.0% arginine, calcium carbonate, and 1000 ppm MFP exhibited statistically significantly (p < 0.05) greater reductions in dentin hypersensitivity in response to tactile (81.9%, 90.5%, and 116.7%) and air blast (39.5%, 56.7%, and 76.7%) stimuli than subjects assigned the 1000 ppm MFP dentifrice after two, four, and eight weeks, respectively. The use of a new dentifrice containing 8.0% arginine, calcium carbonate, and 1000 ppm MFP provides superior efficacy in reducing dentin hypersensitivity (p < 0.05) than a control dentifrice containing 1000 ppm MFP alone after two, four, and eight weeks of use.

Dental Erosion and Dentin Hypersensitivity among Adult Asthmatics and Non-asthmatics Hospital-based: A Preliminary Study.

PubMed

Farag, Zahra Hassan Abdelaziz; Awooda, Elhadi Mohieldin

2016-01-01

Asthma is a chronic inflammatory condition affecting the airways leading to spasm and swelling of the airways. The medications taken for the treatment of asthma can result in dental erosion and dentin hypersensitivity. The aims of this study were to investigate the severity of dental erosion amongst adult asthmatics according to: gender, type and duration of medication taken and to compare dental erosion and dentin hypersensitivity between asthmatics and non-asthmatics. Comparative, cross-sectional hospital based study among 40 asthmatics (M=15 & F=25) and 40 non-asthmatics (M=18 & F=22) in the age range of 18-60 year selected purposefully from Al-Shaab Teaching Hospital in Khartoum city. The Basic Erosive Wear Index was used for dental erosion assessment. Dentine hypersensitivity was determined by giving ice cold water and rated using the Visual Analogue Scale. Chi-square and Student's t-test were used for statistical analysis with P value ≤.05. There was an association between severity of dental erosion and presence of asthma (P=0.03), where asthmatics had a higher degree of erosion (moderate and severe) and non-asthmatics a lower degree. No significant association was found between dental erosion and gender, type and duration of medication among asthmatics group. A statistically significant difference was revealed in the degree of dentin hypersensitivity (P=0.00) among asthmatics (35.13%) and non-asthmatics (14.13%). Asthmatic patients had a higher degree of dental erosion and dentin hypersensitivity compared to non-asthmatics. Among asthmatic patients there was no association between severity of dental erosion and gender, type and duration medication was taken for.

A rapid, efficient, and facile solution for dental hypersensitivity: The tannin–iron complex

PubMed Central

Oh, Dongyeop X.; Prajatelistia, Ekavianty; Ju, Sung-Won; Jeong Kim, Hyo; Baek, Soo-Jin; Joon Cha, Hyung; Ho Jun, Sang; Ahn, Jin-Soo; Soo Hwang, Dong

2015-01-01

Dental hypersensitivity due to exposure of dentinal tubules under the enamel layer to saliva is a very popular and highly elusive technology priority in dentistry. Blocking water flow within exposed dentinal tubules is a key principle for curing dental hypersensitivity. Some salts used in “at home” solutions remineralize the tubules inside by concentrating saliva ingredients. An “in-office” option of applying dense resin sealants on the tubule entrance has only localized effects on well-defined sore spots. We report a self-assembled film that was formed by facile, rapid (4 min), and efficient (approximately 0.5 g/L concentration) dip-coating of teeth in an aqueous solution containing a tannic acid–iron(III) complex. It quickly and effectively occluded the dentinal tubules of human teeth. It withstood intense tooth brushing and induced hydroxyapatite remineralisation within the dentinal tubules. This strategy holds great promise for future applications as an effective and user-friendly desensitizer for managing dental hypersensitivity. PMID:26039461

A rapid, efficient, and facile solution for dental hypersensitivity: The tannin-iron complex.

PubMed

Oh, Dongyeop X; Prajatelistia, Ekavianty; Ju, Sung-Won; Jeong Kim, Hyo; Baek, Soo-Jin; Joon Cha, Hyung; Ho Jun, Sang; Ahn, Jin-Soo; Soo Hwang, Dong

2015-06-03

Dental hypersensitivity due to exposure of dentinal tubules under the enamel layer to saliva is a very popular and highly elusive technology priority in dentistry. Blocking water flow within exposed dentinal tubules is a key principle for curing dental hypersensitivity. Some salts used in "at home" solutions remineralize the tubules inside by concentrating saliva ingredients. An "in-office" option of applying dense resin sealants on the tubule entrance has only localized effects on well-defined sore spots. We report a self-assembled film that was formed by facile, rapid (4 min), and efficient (approximately 0.5 g/L concentration) dip-coating of teeth in an aqueous solution containing a tannic acid-iron(III) complex. It quickly and effectively occluded the dentinal tubules of human teeth. It withstood intense tooth brushing and induced hydroxyapatite remineralisation within the dentinal tubules. This strategy holds great promise for future applications as an effective and user-friendly desensitizer for managing dental hypersensitivity.

Evaluation of a Glass Ionomer Restoration to Treat Hypersensitive Cervical Anatomic Deficiencies.

DTIC Science & Technology

1983-03-01

glass ionomer cement to existing dental cements such as...that the milder pulp reaction to a glass ionomer cement as opposed to a phosphoric acid cement may be explained by the weaker acid makeup of the ASPA...7 Sensitivity Evaluation ........................... 9 Treatment of Dentinal Sensitivity................. 12 Glass Ionomer Cements

Comparative Evaluation of Fluoridated Mouthwash and Sodium Bicarbonate in Management of Dentin Hypersensitivity: An In Vitro SEM Study.

PubMed

Rikame, Vasundhara; Doshi, Yogesh; Horowitz, Robert A; Kevadia-Shah, Vidhi; Shah, Mona

2018-01-01

Sodium bicarbonate (ie, baking soda) can be used as an adjunct to surgical periodontal therapy to reduce dentin hypersensitivity (DH). Sodium bicarbonate mouthwash has numerous appealing attributes, including high availability, low cost, low abrasivity, water solubility, buffering capability, and, in high concentrations, antimicrobial properties. It is also safe to use. The primary underlying cause of DH is open dentinal tubules from loss of either cementum or enamel. The aim of this in vitro study was to evaluate, through scanning electron microscopic examination, the effect of sodium bicarbonate on dentinal tubule occlusion and compare it with that of fluoridated mouthwash.

Laser-assisted treatment of dentinal hypersensitivity: a literature review

PubMed Central

Biagi, Roberto; Cossellu, Gianguido; Sarcina, Michele; Pizzamiglio, Ilaria Tina; Farronato, Giampietro

2015-01-01

Summary The purpose of this literature review was to evaluate the effectiveness of the laser-assisted treatment of dentinal hypersensitivity. A review with inclusion and exclusion criteria was performed from January 2009 to December 2014 with electronic data-bases: MedLine via PubMed, Science Direct and Cochrane Library. Research of paper magazines by hand was not considered. Forty-three articles were selected between literature reviews, in vitro studies, clinical trials, pilot and preliminary studies. The items were divided into laser-used groups for an accurate description, and then the reading of results into various typologies. Laser-assisted treatment reduces dentinal hypersensitivity-related pain, but also a psychosomatic component must be considered, so further studies and more suitable follow-ups are necessary. PMID:26941892

Instant dentin hypersensitivity relief of a single topical application of an in-office desensitizing paste containing 8% arginine and calcium carbonate: a split-mouth, randomized-controlled study.

PubMed

Kapferer, Ines; Pflug, Claudia; Kisielewsky, Irene; Giesinger, Johannes; Beier, Ulrike S; Dumfahrt, Herbert

2013-01-01

The aim of this study was to evaluate the clinical efficacy of an in-office desensitizing paste containing 8% arginine and calcium carbonate relative to calcium carbonate alone in the reduction of dentin hypersensitivity in a randomized, double-blind, split-mouth clinical trial. Sixty teeth (30 subjects) with an air blast hypersensitivity score of 2 or 3 (Schiff Cold Air Sensitivity Scale) were randomly assigned to one of two treatment groups: (1) test paste containing 8% arginine and calcium carbonate (elmex sensitive professional desensitizing paste) and (2) control paste: paris white (calcium carbonate). Tactile and air blast dentin hypersensitivity examinations were performed at baseline, immediately after paste application and 4 and 12 weeks later. A statistically significant difference in air blast (p = 0.001) and tactile (p = 0.047) hypersensitivity reduction over time was observed between the two therapy modes. After 12-weeks, statistically significant differences were indicated between the test and control group with respect to baseline-adjusted mean tactile (41.94%; p = 0.038) and air blast hypersensitivity scores (46.5%; p = 0.017). The tested in-office desensitizing paste containing 8.0% arginine and calcium carbonate provides significantly greater hypersensitivity relief compared to calcium carbonate alone.

Differentiation and displacement: Unpicking the relationship between accounts of illness and social structure

PubMed Central

Gibson, Barry J; Paul, Ninu R

2014-01-01

This article seeks to unpack the relationship between social structure and accounts of illness. Taking dentine hypersensitivity as an example, this article explores the perspective that accounts of illness are sense-making processes that draw on a readily available pool of meaning. This pool of meaning is composed of a series of distinctions that make available a range of different lines of communication and action about such conditions. Such lines of communication are condensed and preserved over time and are often formed around a concept and its counter concept. The study of such processes is referred to as semantic analysis and involves drawing on the tools and techniques of conceptual history. This article goes on to explore how the semantics of dentine hypersensitivity developed. It illustrates how processes of social differentiation led to the concept being separated from the more dominant concept of dentine sensitivity and how it was medicalised, scientised and economised. In short, this study seeks to present the story of how society has developed a specific language for communicating about sensitivity and hypersensitivity in teeth. In doing so, it proposes that accounts of dentine hypersensitivity draw on lines of communication that society has preserved over time. PMID:25197262

Desensitizing toothpaste versus placebo for dentin hypersensitivity: a systematic review and meta-analysis.

PubMed

Bae, Ji-Hyun; Kim, Young-Kyun; Myung, Seung-Kwon

2015-02-01

The aim is to assess the effect of desensitizing toothpaste on dentin hypersensitivity. We searched PubMed, CENTRAL, and Embase on December 20, 2013. Out of the 626 articles searched, a total of 31 randomized controlled clinical trials were included. The Standardized mean differences (SMD) for potassium-containing toothpaste (n = 8) was -1.28 (95% Confidence interval (CI) -2.05 to -0.51; I(2) = 93%); Stannous fluoride- (n = 6) was -1.37 (95% CI, -2.30 to -0.44; I(2) = 95%); Potassium and stannous fluoride- (n = 3) was -2.50 (95% CI, -4.10 to -0.91; I(2) = 95%); Calcium sodium phosphosilicate- (n = 4) was -2.36 (95% CI, -3.72 to -1.00; I(2) = 92%); Arginine- (n = 8) was -3.25 (95% CI, -3.87 to -2.63; I(2) = 86%). The desensitizing effect was favoured in the intervention group treated with potassium-, stannous fluoride-, potassium and stannous fluoride-, calcium sodium phosphosilicate-, and arginine-containing toothpaste compared to placebo. Whereas, strontium-containing toothpaste (SMD, 0.05; 95% CI, -0.34 to 0.44; I(2) = 64%) was found to have no statistically significant desensitizing effect in the meta-analysis of four studies. The study reports that there is sufficient evidence to support the use of potassium-, stannous fluoride-, potassium and stannous fluoride-, calcium sodium phosphosilicate-, and arginine-containing desensitizing toothpastes for dentin hypersensitivity, but not the use of strontium-containing desensitizing toothpaste. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparative Evaluation of Efficacy of Iontophoresis with 0.33% Sodium Fluoride Gel and Diode Laser Alone on Occlusion of Dentinal Tubules

PubMed Central

Varma, Siddhartha; Suragimath, Girish; Abbayya, Keshava; Zope, Sameer Anil; Kale, Vishwajeet

2017-01-01

Introduction Dentinal Hypersensitivity (DH) is one of the most commonly encountered clinical problems. Literature reveals no specific therapy to satisfactorily eliminate dentinal hypersensitivity. Aim The aim of this study was to assess and compare the efficacy of iontophoresis with 0.33% Sodium Fluoride (NaF) gel and diode laser alone in dentinal tubule occlusion. Materials and Methods This in vitro study included 20 teeth with intact root surfaces unaltered by extraction procedure for specimen preparation. Each tooth was cleaned, air dried and cut into three sections. Total 60 sections were prepared (30 longitudinal and 30 transverse sections), which were acid etched. In control group, no treatment was carried. In iontophoresis treatment group, samples were inserted into a foam tray containing 0.33 % NaF Gel and subjected to 1.5 mA output current for three minutes. In laser treatment group, specimens were lased with 980 nm diode laser at 0.5 W/PW (62.2J /cm2) in a noncontact mode for 30 seconds. Specimens were evaluated under Scanning Electron Microscope (SEM) at 10KV to 20KV under x 2000, x5000 magnification for surface characteristics and patency of dentinal tubules. Total number of tubules visible, open, completely and partially occluded were recorded in each microphotograph and compared. Results On comparison, laser group showed the least number of open tubules i.e., 130 (31.1%) followed by iontophoresis group, 155 (51.32%) and control group 417 (100%). Conclusion Diode laser application provided better results as compared to iontophoresis on occlusion of dentinal tubules. Hence, it can be used to treat the patients with DH. PMID:28969290

Comparative Evaluation of Efficacy of Iontophoresis with 0.33% Sodium Fluoride Gel and Diode Laser Alone on Occlusion of Dentinal Tubules.

PubMed

Patil, Anup Raghunath; Varma, Siddhartha; Suragimath, Girish; Abbayya, Keshava; Zope, Sameer Anil; Kale, Vishwajeet

2017-08-01

Dentinal Hypersensitivity (DH) is one of the most commonly encountered clinical problems. Literature reveals no specific therapy to satisfactorily eliminate dentinal hypersensitivity. The aim of this study was to assess and compare the efficacy of iontophoresis with 0.33% Sodium Fluoride (NaF) gel and diode laser alone in dentinal tubule occlusion. This in vitro study included 20 teeth with intact root surfaces unaltered by extraction procedure for specimen preparation. Each tooth was cleaned, air dried and cut into three sections. Total 60 sections were prepared (30 longitudinal and 30 transverse sections), which were acid etched. In control group, no treatment was carried. In iontophoresis treatment group, samples were inserted into a foam tray containing 0.33 % NaF Gel and subjected to 1.5 mA output current for three minutes. In laser treatment group, specimens were lased with 980 nm diode laser at 0.5 W/PW (62.2J /cm 2 ) in a noncontact mode for 30 seconds. Specimens were evaluated under Scanning Electron Microscope (SEM) at 10KV to 20KV under x 2000, x5000 magnification for surface characteristics and patency of dentinal tubules. Total number of tubules visible, open, completely and partially occluded were recorded in each microphotograph and compared. On comparison, laser group showed the least number of open tubules i.e., 130 (31.1%) followed by iontophoresis group, 155 (51.32%) and control group 417 (100%). Diode laser application provided better results as compared to iontophoresis on occlusion of dentinal tubules. Hence, it can be used to treat the patients with DH.

Dentinal tubules occluded by bioactive glass-containing toothpaste exhibit high resistance toward acidic soft drink challenge.

PubMed

Bakri, M M; Hossain, M Z; Razak, F A; Saqina, Z H; Misroni, A A; Ab-Murat, N; Kitagawa, J; Saub, R B

2017-06-01

Dentine hypersensitivity is a common problem attributed by patent dentinal tubules. Ingredients incorporated in toothpastes aim to occlude patent dentinal tubules to minimize the dentine hypersensitivity. However, frequent consumption of acidic soft drinks may reverse the dentinal tubules' occlusion. In this in vitro study, the efficacy of dentinal tubules occluded by commercially available toothpastes to withstand different durations of an acidic soft drink challenge was investigated. One hundred and twenty dentine discs were divided into three groups. The discs from each group were brushed with toothpaste containing bioactive glass, arginine and control toothpaste. Each group was then divided into four subgroups and exposed to acidic soft drink over four different time durations. The scoring and the percentage of occluded dentinal tubules by Novamin-containing toothpaste was significantly better compared with arginine or the control toothpaste. Acidic soft drink challenge reduced the extent of dentinal tubules occlusion along with time. Dentinal tubules occluded by Novamin-containing toothpaste withstand the acidic challenge comparatively for a longer period. The findings demonstrated that occlusion of dentinal tubules is more efficient by the bioactive glass-containing toothpaste and thus may contribute to its better resistance to acidic soft drink challenge. © 2016 Australian Dental Association.

Effect of pulsed Nd:YAG on dentin morphological changes

NASA Astrophysics Data System (ADS)

Moriyama, Eduardo H.; Zangaro, Renato A.; Villaverde, Antonio G. J. B.; Watanabe-Sei, Ii; Munin, Egberto; Sasaki, Luis H.; Otsuka, Daniel K.; Lobo, Paulo D. d. C.; Pacheco, Marcos T. T.; Junior, Durval R.

2002-06-01

Infrared lasers have been used for several clinical applications in dentistry, including laser ablation, oral surgeries and dentin hypersensitivity treatment. Despite of dentin low absorption coefficient in the near infrared spectrum, Nd:YAG laser radiation ((lambda) = 1064 nm) is able to melt the human dentin surface resulting in dentin tubules closure that can suppress the symptoms of dentin hypersensitivity pathology. Objectives: This study aims to analyze, through SEM technique, the morphological changes in dentin surface after Nd:YAG laser irradiation using different parameters in energy distribution. Materials and Methods: In this study sixteen human dentin samples were submitted to Nd:YAG laser radiation using a total energy of 900mJ distributed in one, two, three or six laser pulses with energy for each pulse of 900, 450, 300 or 150 mJ respectively. All the samples were irradiated with laser pulse width of 90ms, pulse intervals of 300 ms and spot size area of 0,005 cm2. Results: SEM analysis suggests that differences in energy distribution results in morphological differences even though the same energy is used for all the samples.

Is photobiomodulation (PBM) effective for the treatment of dentin hypersensitivity? A systematic review.

PubMed

Machado, Alana Cristina; Viana, Ítallo Emídio Lira; Farias-Neto, Aloisio Melo; Braga, Mariana Minatel; de Paula Eduardo, Carlos; de Freitas, Patricia Moreira; Aranha, Ana Cecilia Corrêa

2018-05-01

The present study aims to evaluate the current scientific data regarding the effectiveness of photobiomodulation (PBM) in the treatment of dentin hypersensitivity (DH) as an alternative method for pain control. A systematic review was conducted to assess the effectiveness of PBM as treatment for DH. A complete literature search was performed up to October 2016. Searches were conducted using Boolean operators and MeSH terms. References of all selected full-text articles and related reviews were scanned. A total of 280 articles were identified (241 articles were excluded by the title and abstract). Of the 39 articles selected for analysis, 36 were excluded because they presented one or more exclusion criteria. Therefore, three articles were qualified for inclusion in this systematic review. PBM may not lead to adverse effects provided that adequately controlled parameters are followed when treating DH. More consistent studies should be conducted in order to adequately observe the advantageous therapeutic effect of PBM.

Clinical study to monitor dentinal hypersensitivity with episodic use of a desensitising dentifrice

PubMed Central

Mason, Stephen; Kingston, Rose; Shneyer, Lucy; Harding, Máiréad

2017-01-01

Objectives/Aims: To evaluate continuous and episodic twice-daily usage regimens of a desensitising dentifrice containing 5% calcium sodium phosphosilicate (CSPS). Materials and Methods: In this exploratory, single-centre, randomised, examiner-blind study, subjects with dentinal hypersensitivity were randomised to continuous (24 weeks) use of a 5% CSPS-containing dentifrice or episodic use of the dentifrice comprising two 8-week treatment periods separated by 8 weeks′ use of a standard fluoride dentifrice. Sensitivity was assessed by tactile threshold (Yeaple probe) and evaporative (air) sensitivity (Schiff sensitivity score). Other measures included labelled magnitude scales to assess subjects′ responses to the evaporative stimulus, the Dentine Hypersensitivity Experience Questionnaire and a tooth sensitivity question. Results: Seventy-six subjects were randomised to continuous (n=38) or episodic (n=38) use. Small but statistically significant improvements from baseline in Schiff sensitivity scores were observed at weeks 8, 16 and 24 with both regimens (all P<0.05). Increases from baseline in tactile threshold were not statistically significant. No significant between-regimen difference was observed for any endpoint. No treatment-related adverse events were reported. Discussion: Dentifrice containing 5% CSPS improved dentinal hypersensitivity with both episodic and continuous twice-daily usage regimens over 24 weeks and was well tolerated. Conclusion: No performance differences were observed between the two usage regimens. PMID:29789771

Effect of a novel bioactive glass-ceramic on dentinal tubule occlusion: an in vitro study.

PubMed

Zhong, Y; Liu, J; Li, X; Yin, W; He, T; Hu, D; Liao, Y; Yao, X; Wang, Y

2015-03-01

This in vitro study aimed to assess the ability and efficacy of HX-BGC, a novel bioactive glass-ceramic (SiO2-P2 O5-CaO-Na2 O-SrO), to reduce dentine tubule permeability. Dentine discs from human third molars were etched and randomly allocated into five groups: Group 1--distilled water; Group 2--Sensodyne Repair toothpaste (containing NovaMin®); Group 3--HX-BGC toothpaste (containing 7.5% HX-BGC); Group 4--control toothpaste (without HX-BGC); and Group 5--HX-BGC powder. Specimens were treated daily by brushing with an electric toothbrush for 20 seconds. Between daily treatments (7 days total), specimens were immersed in artificial saliva for 24 hours. Dentine permeability was measured at baseline, after the first treatment, after the first 24-hour immersion in artificial saliva and at the end of day 7. Dentine morphology and surface deposits were observed by scanning electron microscopy after one day and 7 days of treatment, respectively. Sensodyne Repair and bioactive glass-ceramic toothpaste significantly and immediately lowered dentine permeability. The HX-BGC powder group showed the highest reduction in dentine permeability after 7 days of treatment. The novel bioactive glass-ceramic material HX-BGC is effective in reducing dentine permeability by occluding open dentine tubules, indicating that HX-BGC may be a potential treatment for dentine hypersensitivity. © 2015 Australian Dental Association.

Dentin hypersensitivity after teeth bleaching with in-office systems. Randomized clinical trial.

PubMed

Martin, Javier; Fernandez, Eduardo; Bahamondes, Valeria; Werner, Andrea; Elphick, Klaus; Oliveira, Osmir Batista; Moncada, Gustavo

2013-02-01

To comparatively and prospectively compare in a randomized clinical trial, dentin hypersensitivity after treatment with three in-office bleaching systems, based on hydrogen peroxide at different concentrations, with and without light source activation. 88 individuals were included according to inclusion and exclusion criteria. Subjects were randomly divided into the following three treatment groups: Group 1 was treated with three 15-minute applications of hydrogen peroxide at 15% with titanium dioxide (Lase Peroxide Lite) that was light-activated (Light Plus Whitening Lase) with five cycles of 1 minute and 30 seconds each cycle, giving a total treatment time of 45 minutes; Group 2 was treated with three 10-minute applications of hydrogen peroxide at 35% (Lase Peroxide Sensy), activated by light (LPWL) same activation cycles than Group 1, with a total treatment time of 30 minutes; Group 3 was treated with only one application for 45 minutes of hydrogen peroxide at 35% (Whitegold Office) without light activation. Each subject underwent one session of bleaching on the anterior teeth according to the manufacturers' instructions. Dentin sensitivity was recorded with a visual analogue scale (VAS) at baseline, immediately after, and at 7 and 30 days after treatment using a stimulus of an evaporative blowing triple syringe for 3 seconds on the upper central incisors from a distance of 1 cm. A Kruskal-Wallis test followed by Mann-Whitney test was performed for statistical analysis. All groups showed increased sensitivity immediately after treatment. Group 1 displayed less changes relative to baseline with no significant differences (P = 0.104). At 7 and 30 days after treatment, a comparison of VAS values indicated no significant differences between all groups (P = 0.598 and 0.489, respectively).

Cytotoxicity of 45S5 bioglass paste used for dentine hypersensitivity treatment.

PubMed

Bakry, Ahmed Samir; Tamura, Yukihiko; Otsuki, Masayuki; Kasugai, Shohei; Ohya, Keiichi; Tagami, Junji

2011-09-01

45S5 bioglass mixed with 50% phosphoric acid has been suggested to treat dentine hypersensitivity and incipient enamel caries. This study is going to evaluate the biocompatibility of using the aforementioned technique with the rat pulpal cells. The relative cytotoxicity of 45S5 bioglass on rat dental pulp cells was compared to the cytotoxicity of a temporary filling material (Caviton; GC, Japan), Type 1 glass ionomer cement (Fuji I; GC, Tokyo, Japan) and commercial desensitising agent (SuperSeal; Phoenix Dental, Fenton, MI, USA) using a transwell insert model. Cell viability was measured by means of a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The number of viable cell counts were compared using one way ANOVA (p<0.05). The morphological alterations of the pulp cells were observed directly by phase contrast microscope. The results of this study indicated that cell viability recorded by the 45S5 bioglass paste group did not differ significantly from those of the Caviton, glass ionomer or superseal, moreover pulpal cells microscopic analysis revealed that 45S5 bioglass elicited minimal toxic effect. 45S5 bioglass paste can serve as a biocompatible material that can potentially be used safely on dentine. Copyright © 2011 Elsevier Ltd. All rights reserved.

Dentin hypersensitivity treatment by CO2 laser: the influence of the density of dentin tubules and laser-beam incidence

NASA Astrophysics Data System (ADS)

Colojoara, Carmen; Gabay, Shimon; van der Meulen, Freerk W.; van Gemert, Martin J. C.; Miron, Mariana I.; Mavrantoni, Androniki

1997-12-01

Dentin hypersensitivity is considered to be a consequence of the presence of open dentin tubules on the exposed dentin surface. Various methods and materials used in the treatment of this disease are directed to achieve a tubule's occlusion. The purpose of this study was to evaluate under scanning electron microscopy and clinical method the sealing effects of CO2 laser on dentin tubules of human teeth without any damages of the surrounding tissues. Samples of freshly extracted noncarious 3rd molars were used. The teeth were randomly divided in to two groups A and B. The samples of group A were exposed to laser beam in cervical area, directed parallel to their dentin tubules. The teeth of group B were sectioned through a hypothetical carious lesion and lased perpendicularly or obliquely of the dentin tubules. The CO2 laser, at 10.6 micrometers wavelength, was operated only in pulse mode and provided 6.25 - 350 mJ in a burst of 25 pulses each of 250 microsecond(s) time duration with a 2 ms time interval between successive pulses (repetition rate up to 500 mH). Melting of dentin surface and partial closure of exposed dentin tubules were found for all specimens at 6.25 to 31.25 mJ energy. Our results indicated that using CO2 laser in a parallel orientation of laser beam with dentin tubules, the dentin sensitivity can be reduced without any damages of pulp vitality.

New technologies in dentistry

NASA Astrophysics Data System (ADS)

Zanin, Fatima A. A.; Brugnera, Aldo, Jr.; Pecora, Jesus D.

1999-05-01

The technology in dentistry has been developed significantly lately, increasing the technological level of new materials, methods and equipment have been developed. Undoubtedly the CO2 laser has contributed to this evolution particular to the treatment of the infected dentin. CO2 laser can sterilize and promote increase 6 to 8 times of dentin resistance, through the transformation the hydroxyapatite in calcium-phosphato-hydroxyapatite. We can reassure our patients about the use of pulsed CO2 laser due to better preservation of dental structure and its benefits permitting advanced esthetic treatments. The CEREC system, registers a tri-dimensional image of the preparation through a scan system, and sends it to the computer and the operator will edit the restorations so the equipment will finish porcelain restoration. The authors used a new laser 650 nm for caries detection and the other low lever laser (670 nm and 730 nm) considered an auxiliary method to prevent and treat the hypersensitivity in dentin.

Effectiveness of an in-office arginine-calcium carbonate paste on dentine hypersensitivity in periodontitis patients: a double-blind, randomized controlled trial.

PubMed

Pepelassi, Eudoxie; Rahiotis, Christos; Peponi, Eleni; Kakaboura, Afrodite; Vrotsos, Ioannis

2015-01-01

The aim of this single-centre, two-cell, double-blind, randomized controlled clinical study was to evaluate the effectiveness of an in-office desensitizing paste containing 8% arginine and calcium carbonate in providing relief on dentine hypersensitivity immediately after scaling and root planing and its sustained relief over a 6-week period. Fifty periodontitis subjects presenting hypersensitivity were subjected to scaling and root planing and in-office application of either 8% arginine and calcium carbonate desensitizing paste (25 subjects, test group) or fluoride-free prophylaxis paste (25 subjects, control group). Air-blast hypersensitivity was assessed using Schiff and Visual Analogue (VAS) scales at baseline, post-scaling, post-application, 2, 4 and 6 weeks. At all evaluation times, the test group presented significant % reduction in hypersensitivity relative to post-scaling (t-test, p < 0.05) (Schiff - Test: 57, 58.6, 60.2, 68; 28.6, 22.2, 23, 23) (VAS - Test: 60, 55.6, 60.1, 68.4; 25.9, 18.2, 20.6, 22.7) and significant % hypersensitivity difference relative to control (ancova, p < 0.05) (Schiff: 38.9, 45.9, 47.4, 57.7; VAS: 49.1, 48.9, 52.6, 61). The single in-office application of the 8% arginine-calcium carbonate desensitizing paste after scaling and root planing provided significant immediate reduction in dentine hypersensitivity, which sustained over a 6-week period. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of combined application of high- and low-intensity lasers on dentin hypersensitivity: A randomized clinical trial

PubMed Central

Tabibzadeh, Zohreh; Fekrazad, Reza; Esmaeelnejad, Azadeh; Shadkar, Mohammad Mostafa; Khalili Sadrabad, Zahra; Ghojazadeh, Morteza

2018-01-01

Background. Diode lasers (DLs) have demonstrated equal or better desensitizing effects than fluoride varnish, 10% potas-sium nitrate (NK) gel and Gluma. The current study evaluated the desensitizing effect of combined application of DLs with two different output powers and compared it with single DL therapy. Methods. Sixty-two hypersensitive teeth were allocated randomly into two groups: the single group was treated with 3-W DL beam once and in the combined group, the teeth were irradiated three times (the first time with 0.2-W and then with 3-W and the second and third times, 48 and 96 hours after the baseline visit, with 0.2-W DL beams). The amount of dentin hyper-sensitivity (DH) was evaluated, immediately before and after each visit, and 1 week and 1 and 3 months after the first visit. Data analysis was performed using chi-squared test, repeated measurement of ANOVA and Mann-Whitney U test. P<0.05 was considered statistically significant. Results. Statistically significant changes were observed in the means of VAS indices between all the measurement intervals and pretreatment measures, in both experimental groups (P<0.001). The difference in VAS reduction among the groups was not significant when the hypersensitive teeth were stimulated by a periodontal probe and a jet of air (P=0.63 and P=0.12). Conclusion. The results of the present study showed that using both high-intensity and combined DL beams gives rise to significant reductions in DH. There was no significant difference between combined and single laser therapies in the treatment of tooth hypersensitivity. PMID:29732021

The Effect of Calcium Sodium Phosphosilicate on Dentin Hypersensitivity: A Systematic Review and Meta-Analysis

PubMed Central

Chen, Bin; Mei, Li; Yao, Liang; Tian, Jinhui; Li, Huang

2015-01-01

Objective To investigate the effect of calcium sodium phosphosilicate (CSPS) in treating dentin hypersensitivity (DH) and to compare this effect to that of a negative (placebo) control. Materials and Methods Several databases, including Medline, EMBASE, Web of Science, The Cochrane Library, and the Chinese Biomedical Literature Database, were searched to identify relevant articles published through January 2015; grey literature (i.e., academic literature that is not formally published) was also searched. Two authors performed data extraction independently and jointly using data collection forms. The primary outcome was the DH pain response to routine activities or to thermal, tactile, evaporative, or electrical stimuli, and the secondary outcome was the side effects of CSPS use. Each study was evaluated using the Cochrane Collaboration tool for assessing risk bias. Meta-analysis of studies with the same participant demographics, interventions, controls, assessment methods and follow-up periods was performed. The Grading of Recommendations Assessment Development and Evaluation System was used to assess the quality of the evidence and the risk of bias across studies. Results Meta-analysis demonstrated that toothpaste containing 5% CSPS was more effective than the negative control at relieving dentin sensitivity, with the level of evidence classified as “moderate”. In addition, prophylaxis paste containing 15% calcium sodium phosphosilicate was favored over the negative control at reducing post-periodontal therapy hypersensitivity, with the level of evidence categorized as “low”. Only two studies reported side effects of CSPS use. Conclusions The majority of studies found that calcium sodium phosphosilicate was more effective than the negative control at alleviating DH. Because strong evidence is scarce, high-quality, well-designed clinical trials are required in the future before definitive recommendations can be made. PMID:26544035

Comparative clinical study using laser and LED-therapy for orofacial pain relief: dentin hypersensitivity and cervicogenic headache

NASA Astrophysics Data System (ADS)

Lizarelli, Rosane F. Z.; Pizzo, Renata C. A.; Florez, Fernando L. E.; Grecco, Clovis; Speciali, Jose G.; Bagnato, Vanderlei S.

2015-06-01

Considering several clinical situations, low intensity laser therapy has been widely applied in pain relief or analgesia mechanism. With the advent of new LED-based (light emitting diode) light sources, the need of further clinical experiments aiming to compare the effectiveness among them is paramount. The LED system therapeutic use can be denominated as LEDT - Light Emitting Diode Therapy. This study proposed two clinical evaluations of pain relief effect: to dentin hypersensitivity and to cervicogenic headache using different sources of lasers (low and high intensity) and light emitting diodes (LEDs), one emitting at the spectral band of red (630+/- 5nm) and the other one at infrared band (880+/- 5nm). Two different clinical studies were performed and presented interesting results. Considering dentin hypersensitivity, red and infrared led were so effective than the control group (high intensity laser system); by the other side, considering cervicogenic headache, control group (infrared laser) was the best treatment in comparison to red and infrared led system.

Clinical evaluation of the efficacy of an in-office desensitizing paste containing 8% arginine and calcium carbonate in providing instant and lasting relief of dentin hypersensitivity.

PubMed

Schiff, Thomas; Delgado, Evaristo; Zhang, Yun Po; Cummins, Diane; DeVizio, William; Mateo, Luis R

2009-03-01

To determine the efficacy of an in-office desensitizing paste containing 8% arginine and calcium carbonate relative to that of a commercially-available pumice prophylaxis paste in reducing dentin hypersensitivity instantly after a single application following a dental scaling procedure and to establish the duration of sensitivity relief over a period of 4 weeks and 12 weeks. This was a single-center, parallel group, double-blind, stratified clinical study conducted in San Francisco, California, USA. Qualifying adult male and female subjects who presented two hypersensitive teeth with a tactile hypersensitivity score (Yeaple Probe) between 10-50 grams of force and an air blast hypersensitivity score of 2 or 3 (Schiff Cold Air Sensitivity Scale) were stratified according to their baseline hypersensitivity scores and randomly assigned within strata to one of two treatment groups: (1) A Test Paste, a desensitizing paste containing 8% arginine and calcium carbonate (Colgate-Palmolive Co); and (2) A Control Paste, Nupro pumice prophylaxis paste (Dentsply Professional). Subjects received a professionally-administered scaling procedure, after which they were re-examined for tactile and air blast dentin hypersensitivity (Post-Scaling Examinations). The assigned pastes were then applied as the final step to the professional dental cleaning procedure. Tactile and air blast dentin hypersensitivity examinations were again performed immediately after paste application. Subjects were provided with a commercially-available non-desensitizing dentifrice containing 0.243% sodium fluoride (Crest Cavity Protection, Procter & Gamble Co.) and an adult soft-bristled toothbrush and were instructed to brush their teeth for 1 minute, twice daily at home using only the toothbrush and dentifrice provided, for the next 12 weeks. Subjects returned to the testing facility 4 and 12 weeks after the single application of Test or Control paste, having refrained from all oral hygiene procedures and chewing gum for 8 hours and from eating and drinking for 4 hours, prior to each follow-up visit. Assessments of tactile and air blast hypersensitivity, and examinations of oral soft and hard tissue were repeated at these 4- and 12-week examinations. 68 subjects completed the 12-week study. No statistically significant differences from baseline scores were indicated at the Post-Scaling Examinations for either the Test Paste or Control Paste groups. Immediately following product application and 4 weeks after product application, subjects assigned to the Test Paste group exhibited statistically significant improvements from baseline with respect to baseline-adjusted mean air blast (44.1% and 45.9% respectively) and mean tactile hypersensitivity scores (156.2% and 170.3% respectively). At the same time points, subjects assigned to the Control Paste group exhibited statistically significant improvements from baseline with respect to baseline-adjusted mean air blast (15.1% and 8.9% respectively) and mean tactile hypersensitivity scores (43.1% and 8.3% respectively). Immediately following application of the assigned paste and 4 weeks later, the Test Paste group demonstrated statistically significant reductions in dentin hypersensitivity with respect to baseline-adjusted mean air blast (34.1% and 40.6% respectively) and mean tactile hypersensitivity scores (79.0% and 149.6% respectively), compared to the Control Paste group. No statistically significant differences were exhibited between paste groups at the Post-Scaling and 12-week examinations with respect to mean tactile and baseline-adjusted mean air blast hypersensitivity scores.

Effect of theobromine-containing toothpaste on dentin tubule occlusion in situ.

PubMed

Amaechi, Bennett T; Mathews, Sapna M; Mensinkai, Poornima K

2015-01-01

Dentin hypersensitivity (DH) is treated by either occlusion of dentin tubules or nerve desensitization. This in situ study compared dentin tubules occlusion by theobromine-containing dentifrices with (Theodent-classic-F®, TCF) and without (Theodent-classic®, TC) fluoride with 1,500 ppm fluoride toothpaste, Colgate®-Regular (Fluoride) and Novamin®-containing toothpaste, Sensodyne®-5000-Nupro (Novamin®). Each subject wore four intraoral appliances bearing dentin blocks while using one of four test dentifrices (n = 20/dentifrice) twice daily for 7 days. The four appliances were removed successively after 1, 2, 3, and 7 days. Treated blocks and their control (untreated) blocks were examined with scanning electron microscopy (SEM). Effects were compared statistically (ANOVA/Tukey's) based on percentage of surface area covered by deposited precipitate layer (%DPL) and percentage of fully open (%FOT), partially occluded (%POT), and completely occluded (%COT) tubules in each block calculated relative to the number of tubules in their control blocks. SEM observation indicated an increased %COT and %DPL over time. After 1 and 2 days, %COT was comparable with TC and TCF, and significantly (p < 0.05) higher compared with Novamin® and Fluoride. Following 3 and 7 days, %COT was comparable among TC, TCF, and Novamin®, but remained significantly lower in Fluoride. At any time, %DPL was significantly (p < 0.05) higher in TC, TCF, and Novamin® compared with Fluoride. Theobromine-containing toothpastes with and without fluoride have equal potential in occluding dentin tubules within a shorter time period than Novamin®-containing toothpaste; however, the three demonstrated equal potential after 1 week, but not the fluoride toothpaste. Theobromine-containing toothpaste promoted dentin tubule occlusion thus shows potential to relief DH.

Comparative clinical evaluation of gallium-aluminum-arsenide diode laser and potassium nitrate in treating dentinal hypersensitivity.

PubMed

Tevatia, Siddharth; Khatri, Vivek; Sharma, Nikhil; Dodwad, Vidya

2017-01-01

Dentinal hypersensitivity (DH) is a chronic disorder in which patients report sharp and acute pain to a variety of stimuli. Till date, a standardized procedure to treat DH is missing, though several alternative treatment strategies have been designed, including laser therapies. The aim of the study was to treat DH with minimum chemical concentration and least laser energy level with longer follow-up period. One hundred and twenty patients were randomly divided into four groups: (i) Group 1-5% potassium nitrate (KNO 3 ); (ii) Group 2 - gallium-aluminum-arsenide diode laser (62.2 J/cm 2 , wavelength - 980 nm, noncontact pulse mode, and power wattage - 0.5 W); (iii) Group 3 - combined 5% KNO 3 and the diode laser; and (iv) Group 4 - placebo (control). The visual analog scale (VAS) scores were recorded, analyzed, and compared to tactile stimuli, cold water, and air blast tests at different intervals for 6 weeks. Synergistic use of 5% KNO 3 and diode laser (Group 3) significantly reduced the DH pain, which was almost negligible after 6 th week (97%-99% of the pain was reported to be relieved) and showed promising results than any other studied groups. Further, the diode laser (Group 2) showed better results than 5% KNO 3 (Group 1). One-way ANOVA and Bonferroni correction post hoc test revealed the combination of groups with significant differences in the mean VAS scores at the different interval of time ( P < 0.01). Convincingly, the combined application of 5% KNO 3 with the diode laser can be recommended for treating DH patients.

Evaluation of ex vivo effectiveness of commercial desensitizing dentifrices

PubMed Central

Mockdeci, Hanny; Polonini, Hudson; Granato, Ana-Paula; Raposo, Nádia; Chaves, Maria-das Graças

2017-01-01

Background Dentin hypersensitivity is a short, severe pain with fast onset. Therapy aims to either prevent or decrease neural transmission or physically occlude the dentinal tubules. This study aimed to evaluate the effectiveness of commercial desensitizing dentifrice by means of an ex vivo method. Material and Methods Samples (n=8 lower human premolars for each group) were randomly allocated into: G1- brushing with Colgate®Sensitive Pro-Relief; G2- brushing with Sensodyne®Rapid Relief; G3- brushing with Sensodyne®Repair & Protect; and G4- brushing with Colgate®Maximum Cavity Protection. The test bodies were submitted to simulated toothbrushing and dentifrices were analyzed regarding their hydrodynamic size, polydispersity index (PI) and zeta potential. Specimens were evaluated using: scanning electron microscopy (SEM); spectroscopy energy dispersive X-ray (EDS); and profilometry. A qualitative analysis of the photomicrographs and topographies was performed. Results The dentifrices showed statistical similar physical and chemical characteristics. They also demonstrated obliteration of dentinal tubules when micrographs were observed. Regarding the chemical elements present in the dentin samples, there was a statistically significant difference between the control and experimental surfaces in the four groups. Conclusions Joint data analysis shows that the desensitizing dentifrice showed better results with regards to the obliteration of dentinal tubules compared to positive and negative controls. Key words:Dentin hypersensitivity, dentin desensitizing agents, toothpastes. PMID:28469813

Comparative clinical evaluation of gallium-aluminum-arsenide diode laser and potassium nitrate in treating dentinal hypersensitivity

PubMed Central

Tevatia, Siddharth; Khatri, Vivek; Sharma, Nikhil; Dodwad, Vidya

2017-01-01

Context: Dentinal hypersensitivity (DH) is a chronic disorder in which patients report sharp and acute pain to a variety of stimuli. Till date, a standardized procedure to treat DH is missing, though several alternative treatment strategies have been designed, including laser therapies. Aim: The aim of the study was to treat DH with minimum chemical concentration and least laser energy level with longer follow-up period. Materials and Methods: One hundred and twenty patients were randomly divided into four groups: (i) Group 1-5% potassium nitrate (KNO3); (ii) Group 2 - gallium-aluminum-arsenide diode laser (62.2 J/cm2, wavelength - 980 nm, noncontact pulse mode, and power wattage - 0.5 W); (iii) Group 3 - combined 5% KNO3 and the diode laser; and (iv) Group 4 - placebo (control). The visual analog scale (VAS) scores were recorded, analyzed, and compared to tactile stimuli, cold water, and air blast tests at different intervals for 6 weeks. Results: Synergistic use of 5% KNO3 and diode laser (Group 3) significantly reduced the DH pain, which was almost negligible after 6th week (97%–99% of the pain was reported to be relieved) and showed promising results than any other studied groups. Further, the diode laser (Group 2) showed better results than 5% KNO3 (Group 1). One-way ANOVA and Bonferroni correction post hoc test revealed the combination of groups with significant differences in the mean VAS scores at the different interval of time (P < 0.01). Conclusions: Convincingly, the combined application of 5% KNO3 with the diode laser can be recommended for treating DH patients. PMID:29491586

A comparative evaluation to assess the efficacy of 5% sodium fluoride varnish and diode laser and their combined application in the treatment of dentin hypersensitivity

PubMed Central

Suri, Isha; Singh, Poonam; Shakir, Quaid Johar; Shetty, Arvind; Bapat, Ranjeet; Thakur, Roshani

2016-01-01

Background: Dentin hypersensitivity (DH) is an age old complaint with a great number of treatment modalities, but none of these are totally effective till date. Lasers being one of the latest treatment options in periodontics, a study was conducted to test the efficacy of diode laser (DL) in DH alone and in comparison with 5% sodium fluoride (NaF) varnish. Aim: The aim of the present study was to compare the effectiveness of 5% topical NaF varnish and 980 nm gallium aluminum arsenide (GaAlAs) DL alone and combination of 5% NaF + 980 nm GaAlAs DL in the management of DH. Materials and Methods: The study was conducted on 120 teeth in thirty patients with DH assessed by tactile and air blast (AB) stimuli measured by visual analog scale (VAS). Teeth were randomly divided into Group 1 (P) placebo-treated control group, Group 2 (NaF) treated by 5% NaF varnish, Group 3 (DL) treated with 980 nm DL, and Group 4 (NaF + DL) treated with both 5% NaF varnish and 980 nm DL (combination group). Results: There was a significant reduction in DH. The VAS reduction percentages were calculated, and there was a significant decrease in DH above all in G4 (NaF + DL) than G3 (DL) and G2 (NaF). Conclusion: Even though all the three groups (2, 3, and 4) showed improvement in terms of DH reduction, 5% NaF varnish with DL showed the best results among all the groups. PMID:27563205

Association of dentine hypersensitivity with different risk factors - a cross sectional study.

PubMed

Vijaya, V; Sanjay, Venkataraam; Varghese, Rana K; Ravuri, Rajyalakshmi; Agarwal, Anil

2013-12-01

This study was done to assess the prevalence of Dentine hypersensitivity (DH) and its associated risk factors. This epidemiological study was done among patients coming to dental college regarding prevalence of DH. A self structured questionnaire along with clinical examination was done for assessment. Descriptive statistics were obtained and frequency distribution was calculated using Chi square test at p value <0.05. Stepwise multiple linear regression was also done to access frequency of DH with different factors. The study population was comprised of 655 participants with different age groups. Our study showed prevalence as 55% and it was more common among males. Similarly smokers and those who use hard tooth brush had more cases of DH. Step wise multiple linear regression showed that best predictor for DH was age followed by habit of smoking and type of tooth brush. Most aggravating factors were cold water (15.4%) and sweet foods (14.7%), whereas only 5% of the patients had it while brushing. A high level of dental hypersensitivity has been in this study and more common among males. A linear finding was shown with age, smoking and type of tooth brush. How to cite this article: Vijaya V, Sanjay V, Varghese RK, Ravuri R, Agarwal A. Association of Dentine Hypersensitivity with Different Risk Factors - A Cross Sectional Study. J Int Oral Health 2013;5(6):88-92 .

Evaluating the statistical methodology of randomized trials on dentin hypersensitivity management.

PubMed

Matranga, Domenica; Matera, Federico; Pizzo, Giuseppe

2017-12-27

The present study aimed to evaluate the characteristics and quality of statistical methodology used in clinical studies on dentin hypersensitivity management. An electronic search was performed for data published from 2009 to 2014 by using PubMed, Ovid/MEDLINE, and Cochrane Library databases. The primary search terms were used in combination. Eligibility criteria included randomized clinical trials that evaluated the efficacy of desensitizing agents in terms of reducing dentin hypersensitivity. A total of 40 studies were considered eligible for assessment of quality statistical methodology. The four main concerns identified were i) use of nonparametric tests in the presence of large samples, coupled with lack of information about normality and equality of variances of the response; ii) lack of P-value adjustment for multiple comparisons; iii) failure to account for interactions between treatment and follow-up time; and iv) no information about the number of teeth examined per patient and the consequent lack of cluster-specific approach in data analysis. Owing to these concerns, statistical methodology was judged as inappropriate in 77.1% of the 35 studies that used parametric methods. Additional studies with appropriate statistical analysis are required to obtain appropriate assessment of the efficacy of desensitizing agents.

Laser therapy may be better than topical desensitizing agents for treating dentin hypersensitivity.

PubMed

Blatz, Markus B

2012-09-01

Two independent reviewers screened the databases MEDLINE, EMBASE, the Cochrane Central Register of ControlledTrials, the National Research Register, and the Cochrane Oral HealthGroup'sTrials Register for articles written in English between 1977 and January1, 2010. The inclusion criteria comprised randomized controlled trials (RCTs) involving the application of laser desensitizing procedures and topical desensitizing agents in patients with at least 2 or more hypersensitive teeth confirmed by evaporative stimulus or tactile hypersensitivity assessment. Trial groups needed to receive laser therapy, whereas the control groups received topical desensitizing agents, such as fluoride varnish, dentin bonding agents, or others. Outcomes had to be measured by clinical performance (decrease of hypersensitivity) and/or patients' self-assessment. Studies with loss in follow-up greater than 20% or with confusing data/probable errors were excluded. A total of 176 potential relevant titles, abstracts, and articles were found, 28 of which were screened for further evaluation. Out of these, 8 trials met all inclusion criteria, involving a total of 234 patients. The quality of these trials was assessed according to the Cochrane Handbook for Systematic Reviews of Interventions. Accordingly, only 1 study was classified as A level, 5 as B level, and 2 as C level. A meta-analysis was not performed because of the heterogeneity of the studies. Studies that assess the application of laser desensitizing procedures in reducing dentinal hypersensitivity. The primary outcome was reduction of tooth sensitivity following treatment with either a laser or a topical desensitizing agent. Evaluations were made at varying intervals up to 6 months after treatment. Eight trials reporting on a total of 234 patients were included based on the specified criteria and 20 articles were excluded. Sample size in each of the included studies varied from 20 to 70 patients with differing follow-up intervals of up to 6 months. Most studies used Visual Analog Scale scores or other subjective tools to assess sensitivity. All 8 studies compared one kind of laser versus one kind of topical desensitizingagent. However, types of lasers as well as types of desensitizing agents differed among the reviewed studies. Half of the studies compared gallium-aluminum-arsenide (GaAlAs) lasers with various topical desensitizing agents; however, findings were conflicting. Two moderate-quality trials indicated that GaAlAs laser and the control desensitizing agents preformed similarly. Another moderate-quality trial demonstrated that the application of a bonding agent was significantly better than a GaAlAs laser in the reduction of hypersensitivity. The only reviewed study that was classified as an A-level study revealed a significantly greater immediate and long-term desensitizing effect than the control. The remaining studies involved Nd:YAG, Er:YAG, and CO(2) lasers, all of them reporting a slightly greater decrease in sensitivity as compared with topical desensitizing agents. Five of 8s tudies reported on the safety of laser application and did not find any detrimental pulpal effects, allergic reactions, or clinically detectable complications during follow-up. The authors concluded that the results obtained from the 8 studies included in this systematic review were conflicting but indicated a slight clinical advantage of laser therapy over topical medicaments in the treatment of dentin hypersensitivity. It was further concluded that application of lasers under controlled parameters for this indication may not lead to adverse effects. Copyright © 2012. Published by Mosby, Inc. All rights reserved.

Association of Dentine Hypersensitivity with Different Risk Factors – A Cross Sectional Study

PubMed Central

Vijaya, V; Sanjay, Venkataraam; Varghese, Rana K; Ravuri, Rajyalakshmi; Agarwal, Anil

2013-01-01

Background: This study was done to assess the prevalence of Dentine hypersensitivity (DH) and its associated risk factors. Materials & Methods: This epidemiological study was done among patients coming to dental college regarding prevalence of DH. A self structured questionnaire along with clinical examination was done for assessment. Descriptive statistics were obtained and frequency distribution was calculated using Chi square test at p value <0.05. Stepwise multiple linear regression was also done to access frequency of DH with different factors. Results: The study population was comprised of 655 participants with different age groups. Our study showed prevalence as 55% and it was more common among males. Similarly smokers and those who use hard tooth brush had more cases of DH. Step wise multiple linear regression showed that best predictor for DH was age followed by habit of smoking and type of tooth brush. Most aggravating factors were cold water (15.4%) and sweet foods (14.7%), whereas only 5% of the patients had it while brushing. Conclusion: A high level of dental hypersensitivity has been in this study and more common among males. A linear finding was shown with age, smoking and type of tooth brush. How to cite this article: Vijaya V, Sanjay V, Varghese RK, Ravuri R, Agarwal A. Association of Dentine Hypersensitivity with Different Risk Factors – A Cross Sectional Study. J Int Oral Health 2013;5(6):88-92 . PMID:24453451

A comparative evaluation of propolis and 5.0% potassium nitrate as a dentine desensitizer: A clinical study

PubMed Central

Purra, Aamir Rashid; Mushtaq, Mubashir; Acharya, Shashi Rashmi; Saraswati, Vidya

2014-01-01

Aim: The purpose of this clinical study was to evaluate the efficacy of saturated ethanolic solution of Propolis for the treatment of dentin hypersensitivity. Materials and Methods: Ten patients aged 20-40 years with 156 hypersensitive teeth were selected for a 3-month study. Each patient was subjected to treatment with saturated ethanolic solution of Propolis, 5% potassium nitrate and distilled water. The patients were recalled at seventh day, 2 weeks and 4 weeks for the application of the agent and re-evaluation. The final re-evaluation of the patients was done after 3 months from the first application. The responses of the patients to the test temperatures were converted to a ranking and data was statistically analyzed. A statistical analysis was done using ANOVA and Bonferroni test and Tukey HSD test for multicomparison. Results: The results between the Propolis group and the potassium nitrate group showed no significant difference in the immediate post-treatment period; however, the results were significant at the end of first week and second week. At 4 weeks and 3 months period, a comparison between the groups again showed no significant difference. Conclusion: It was concluded that Propolis was more effective than 5% potassium nitrate in relieving dentinal hypersensitivity and had an immediate and sustained effect. PMID:25210261

Effectiveness of a baking soda toothpaste delivering calcium and phosphate in reducing dentinal hypersensitivity.

PubMed

Ghassemi, A; Hooper, W; Winston, A E; Sowinski, J; Bowman, J; Sharma, N

2009-01-01

The purpose of this controlled clinical trial was to determine the effectiveness and safety of a single-phase dentifrice that delivers calcium, phosphate, and fluoride to the tooth surface (Arm & Hammer Enamel Care for Sensitive Teeth toothpaste, United Kingdom) in reducing dentinal hypersensitivity. Two-hundred and eight qualifying subjects were randomly assigned to either the Enamel Care dentifrice group or a control dentifrice group, and brushed twice daily with their assigned dentifrice for eight weeks. Pain/discomfort in response to a thermal stimulus was assessed at baseline, week 4, and week 8 using a Visual Analogue Scale (VAS; primary outcome variable) and the Schiff Thermal Sensitivity Scale (STSS; secondary outcome variable). After eight weeks, volunteers from the Enamel Care group were switched to the control dentifrice and participated in a second eight-week study to determine the degree of persistence of pain reduction. Both groups had statistically significant VAS score reductions from baseline at weeks 4 and 8, with mean VAS scores in the Enamel Care group decreasing by 45.6% at week 4 and 61.1% at week 8 (p < 0.0001). Enamel Care was statistically significantly more effective than the control at weeks 4 and 8, with respective mean VAS reductions of 63% (p < 0.0001) and 33% (p = 0.0004) greater than the control. Consistent with the VAS score results, the Enamel Care group had respective statistically significant STSS score reductions of 77% and 58% greater than the control group (p < 0.0001). The reductions in dentinal hypersensitivity seen in the Enamel Care group at week 8 persisted for an additional eight weeks, during which the subjects discontinued use of Enamel Care and brushed with the control dentifrice. Enamel Care for Sensitive Teeth toothpaste (United Kingdom) is an effective dentifrice for the management of dentinal hypersensitivity, and its efficacy persists for a least eight weeks following discontinued product use.

In vivo remineralization of dentin using an agarose hydrogel biomimetic mineralization system

NASA Astrophysics Data System (ADS)

Han, Min; Li, Quan-Li; Cao, Ying; Fang, Hui; Xia, Rong; Zhang, Zhi-Hong

2017-02-01

A novel agarose hydrogel biomimetic mineralization system loaded with calcium and phosphate was used to remineralize dentin and induce the oriented densely parallel packed HA layer on defective dentin surface in vivo in a rabbit model. Firstly, the enamel of the labial surface of rabbits’ incisor was removed and the dentin was exposed to oral environment. Secondly, the hydrogel biomimetic mineralization system was applied to the exposed dentin surface by using a custom tray. Finally, the teeth were extracted and evaluated by scanning electron microscopy, X-ray diffraction, and nanoindentation test after a certain time of mineralization intervals. The regenerated tissue on the dentin surface was composed of highly organised HA crystals. Densely packed along the c axis, these newly precipitated HA crystals were perpendicular to the underlying dental surface with a tight bond. The demineralized dentin was remineralized and dentinal tubules were occluded by the grown HA crystals. The nanohardness and elastic modulus of the regenerated tissue were similar to natural dentin. The results indicated a potential clinical use for repairing dentin-exposed related diseases, such as erosion, wear, and dentin hypersensitivity.

Comparison of conventional therapies for dentin hypersensitivity versus medical hypnosis.

PubMed

Eitner, Stephan; Bittner, Christian; Wichmann, Manfred; Nickenig, Hans-Joachim; Sokol, Biljana

2010-10-01

This study compared the efficacy of conventional treatments for dentin hypersensitivity (DHS) and hypnotherapy. During a 1-month period at an urban practice in a service area of approximately 22,000 inhabitants, all patients were examined. A total of 102 individuals were included in the evaluation. Values of 186 teeth were analyzed. The comparison of the different treatment methods (desensitizer, fluoridation, and hypnotherapy) did not show significant differences in success rates. However, a noticeable difference was observed in terms of onset and duration of effect. For both desensitizer and hypnotherapy treatments, onset of effect was very rapid. Compared to the other methods studied, hypnotherapy effects had the longest duration. In conclusion, hypnotherapy was as effective as other methods in the treatment of DHS.

In Vitro Evaluation of Dentin Hydraulic Conductance After 980 nm Diode Laser Irradiation.

PubMed

Rizzante, Fabio A P; Maenosono, Rafael M; Duarte, Marco A H; Furuse, Adilson Y; Palma-Dibb, Regina G; Ishikiriama, Sérgio K

2016-03-01

Dentin hypersensitivity treatments are based on the physical obliteration of the dentinal tubules to reduce hydraulic conductance. The aim of the present study is to evaluate the hydraulic conductance of bovine root dentin after irradiation with a 980-nm diode laser, with or without associated fluoride varnish. Sixty bovine root dentin specimens were divided into six groups (n = 10 in each group): G1, G3, and G5 (0.5 W, 0.7 W, and 1 W diode laser, respectively); G2, G4, and G6 (fluoride varnish application + 0.5 W, 0.7 W, and 1 W diode laser, respectively). The dentin hydraulic conductance was evaluated at four time periods with a fluxmeter: 1) with smear layer, 2) after 37% phosphoric acid etching, 3) after the treatments, and 4) after 6% citric acid challenge. After the dentinal fluid flow measurements, specimens were also evaluated for mineral composition using energy dispersive X-ray spectroscopy (EDS). Analysis demonstrated a better result with increased irradiation power (P < 0.001), especially if the diode laser irradiation was associated with the application of fluoride varnish (P < 0.001), ensuring a greater reduction in permeability. Considering the groups treated only with laser irradiation, the 1 W group was superior when compared with the 0.5 W and 0.7 W irradiated groups immediately after treatment (P < 0.001). After citric acid testing, all groups showed similar results, except when comparing the 1 W groups with the 0.5 W groups (P = 0.04). EDS results of the irradiated groups showed an increase in the proportion of calcium and phosphorus ions, which demonstrates a superficial composition modification after laser treatments. Laser irradiation of exposed dentin promoted significant reduction in the dentin hydraulic conductance, mainly with higher energy densities and association with fluoride varnish.

A biomimetic approach to ameliorate dental hypersensitivity by amorphous polyphosphate microparticles.

PubMed

Müller, Werner E G; Neufurth, Meik; Tolba, Emad; Wang, Shunfeng; Geurtsen, Werner; Feng, Qingling; Schröder, Heinz C; Wang, Xiaohong

2016-06-01

Dental hypersensitivity has become one of the most common and most costly diseases in the world, even though those maladies are very rarely life threatening. Using amorphous microparticles, fabricated from the natural polymer (polyphosphate), we intend to reseal the dentinal tubules exposed and reduce by that the hypersensitivity. Amorphous microparticles (termed aCa-polyP-MP) were prepared from Na-polyphosphate (polyP) and CaCl2, then incubated with human teeth. The potential of the microparticles to plug the dentinal tubules was determined by microscopic and spectroscopic techniques. We demonstrate that, in contrast to polyP, the aCa-polyP-MP efficiently reseal dentinal tubules exposed at the tooth surface. Scanning electron microscopical (SEM) and energy dispersive X-ray spectroscopic (EDX) studies showed that the tooth cement and dentin surfaces, incubated with aCa-polyP-MP, form a nearly homogenous, approximately 50-μm thick solid polyP layer on the tooth cement and dentin surfaces, while no coating on the tooth surface, incubated with Na-polyP [Ca(2+)], was observed. Determination of the mechanical properties of the polyP coating revealed a Martens hardness of 3.85±0.64GPa and a reduced elastic modulus of 94.72±8.54GPa already after a 3h exposure to the aCa-polyP-MP, which become close to those of the natural enamel (4.33±0.69GPa and 101.61±8.52GPa, respectively) after prolonged incubation periods. In addition, aCa-polyP-MP turned out to display morphogenetic activity. Incubation of precursor odontoblasts cultures in the presence of aCa-polyP-MP resulted in a 7-fold increase of the steady-state-expression level of the gene encoding for the alkaline phosphatase (ALP) during a 7 d incubation period. Ca-polyP microparticles, consisting of the biocompatible natural polymer polyP, provide a potential sealing material for dentinal tubules on the tooth surface. Copyright © 2016 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Measurement of dentin hypersensitivity with the Jay Sensitivity Sensor Probe and the Yeaple probe to compare relief from dentin hypersensitivity by dentifrices.

PubMed

Kakar, Ashish; Kakar, Kanupriya

2013-05-01

To compare relief from dentin hypersensitivity (DH) after use of dentifrices formulated with potassium nitrate or fluoride. For the study, DH evaluations were conducted with the Jay Sensitivity Sensor Probe (Jay Probe), a novel tactile hypersensitivity instrument, in conjunction with three other DH methods, i.e. Yeaple probe (tactile), air blast, and the Visual Analog Scale (VAS). Adults (n = 100) who presented two teeth with DH and met study criteria were enrolled for this double-blind, randomized, parallel, controlled clinical trial conducted in an outpatient setting. DH evaluations at baseline were conducted by the tactile, air blast, and VAS methods. Subjects were randomly assigned a dentifrice formulated with 5% potassium nitrate and 1,000 ppm fluoride (as sodium monofluorophosphate) (Colgate Sensitive toothpaste; Test) or a commercially available fluoride dentifrice with 1,000 ppm fluoride as sodium monofluorophosphate (Colgate Cibaca toothpaste; Negative control). Subjects were recalled for DH evaluations after 4 and 8 weeks of product use. 85 subjects completed the entire study with evaluable results. Both treatments resulted in significant reductions in DH from baseline to all recall visits. In comparison to the Negative control, subjects in the Test group demonstrated significantly greater reductions for all DH evaluations at both 4 and 8 weeks (P < 0.05). Average tactile DH scores at week 8 for the Test and Negative control groups were 36.25 and 15.24 with the Yeaple probe and 35 and 12.43 with the Jay probe. Correspondingly, subjects in the Test group demonstrated significantly greater reductions in air blast and VAS responses for DH than those in the Negative control group (P < 0.05).

Desensitizing efficacy of nano-carbonate apatite dentifrice and Er,Cr:YSGG laser: a randomized clinical trial.

PubMed

Lee, Su-Young; Jung, Hoi-In; Jung, Bock-Young; Cho, Young-Sik; Kwon, Ho-Keun; Kim, Baek-Il

2015-01-01

The aim of this study was to evaluate the desensitizing effects of a dentifrice containing nano-carbonate apatite (n-CAP) and Er,Cr:YSGG laser in the treatment of dentin hypersensitivity. Most studies of hypersensitivity treatment have been conducted with different methods of professional treatment and self-care in each study. Moreover, clinical studies that compare self-care and professional treatment have not yet been published. Eighty-two patients with dentin hypersensitivity were divided randomly into three groups: (1) a control group with strontium chloride dentifrice (SC), (2) n-CAP dentifrice (n-CAP), and (3) an Er,Cr:YSGG laser (laser) group. The study was conducted for 4 weeks: a treatment period of 2 weeks and a maintenance period of 2 subsequent weeks. The SC and n-CAP groups were instructed to brush their teeth twice a day for 1 min. The laser group visited twice at 1 week intervals for irradiation of the sensitive teeth. The desensitizing effect was evaluated by assessing the tactile sensitivity using the visual analogue scale (VAS), and evaporative air sensitivity was determined using an air blast score (ABS). The n-CAP group and the laser group showed significantly different desensitizing effects in VAS after 4 weeks (69% and 63%, respectively) and a 33% (p<0.05) and 3% (p>0.05) desensitizing effect, respectively, in VAS during the maintenance period. The n-CAP and the laser were effective in reducing dentin hypersensitivity. The laser had a superior desensitizing effect at the initial stage, whereas the n-CAP maintained its effect for a relatively longer time in clinical situations.

Dentine Tubule Occlusion by Novel Bioactive Glass-Based Toothpastes

PubMed Central

Hill, Robert G.; Chen, Xiaojing

2018-01-01

There are numerous over-the-counter (OTC) and professionally applied (in-office) products and techniques currently available for the treatment of dentine hypersensitivity (DH), but more recently, the use of bioactive glasses in toothpaste formulations have been advocated as a possible solution to managing DH. Aim. The aim of the present study, therefore, was to compare several bioactive glass formulations to investigate their effectiveness in an established in vitro model. Materials and Methods. A 45S5 glass was synthesized in the laboratory together with several other glass formulations: (1) a mixed glass (fluoride and chloride), (2) BioMinF, (3) a chloride glass, and (4) an amorphous chloride glass. The glass powders were formulated into five different toothpaste formulations. Dentine discs were sectioned from extracted human teeth and prepared for the investigation by removing the cutting debris (smear layer) following sectioning using a 6% citric acid solution for 2 minutes. Each disc was halved to provide test and control halves for comparison following the brushing of the five toothpaste formulations onto the test halves for each toothpaste group. Following the toothpaste application, the test discs were immersed in either artificial saliva or exposed to an acid challenge. Results. The dentine samples were analyzed using scanning electron microscopy (SEM), and observation of the SEM images indicated that there was good surface coverage following artificial saliva immersion. Furthermore, although the acid challenge removed the hydroxyapatite layer on the dentine surface for most of the samples, except for the amorphous chloride glass, there was evidence of tubular occlusion in the dentine tubules. Conclusions. The conclusions from the study would suggest that the inclusion of bioactive glass into a toothpaste formulation may be an effective approach to treat DH. PMID:29849637

Effect of Nd:YAG Laser Irradiation on the Number of Open Dentinal Tubules and Their Diameter with and without Smear of Graphite: An in Vitro Study

PubMed Central

Maleki-pour, Mohammad Reza; Birang, Reza; Khoshayand, Maryam; Naghsh, Narges

2015-01-01

Introduction: Dentin hypersensitivity (DH) is characterized by tooth pain arising from exposure of dental roots. In this study the efficiency of neodymium yttrium-aluminum-garnet (Nd:YAG) laser in association with graphite on dentinal surface changes as the alternative to the treatment of DH was evaluated. Methods: Sixteen noncarious human third molars were collected and sectioned into 5 parts from cementoenamel junction (CEJ) to the furcation area. The prepared samples were randomly assigned into five groups (Gs) of each 16: Control (G1), treated by Nd:YAG laser at 0.5 W (G2), irradiation of Nd:YAG with a 0.25 W output power(G3), smeared with graphite and then using Nd:YAG laser at output powers of 0.5 W (G4) and 0.25 W (G5). For all groups the parameters were 15 Hz, 60 s, at two stages and with a right angle irradiation. The number and diameter of dentinal tubules (DT) were compared and analyzed by SPSS software, One way ANOVA and Post hoc LSD tests. Results:The number of open dentinal tubules varied significantly between all groups except among G1 with G3 and G2 with G5. Multiple comparison tests also exhibited significant differences regarding the diameter of tubules between the groups two by two except among G2 with G5. Conclusion: Nd:YAG laser used at 0.25 W and 0.5 W with application of graphite smear was able to reduce the number and diameter of dentinal tubules. PMID:25699166

Comparative Evaluation of the Effects of Nd:YAG Laser and a Desensitizer Agent on the Treatment of Dentin Hypersensitivity: A Clinical Study

PubMed Central

Lopes, Anely Oliveira

2013-01-01

Abstract Objective: The aim of this randomized longitudinal clinical study was to assess different treatment protocols for dentin hypersensitivity with high-power laser, desensitizing agent, and its association between high-power laser and desensitizing agent, for a period of 6 months. Background data: The literature shows a lack of treatment for dentin hypersensitivity, and lasers are contemporary alternatives. Methods: After inclusion and exclusion analysis, volunteers were selected. The lesions were divided into three groups (n=10): G1, Gluma Desensitizer (Heraeus Kulzer); G2, Nd:YAG Laser (Power Laser™ ST6, Lares Research®) contact mode, laser protocol of 1.5 W, 10 Hz, and 100 mJ,≈85 J/cm2, four irradiations performed, each for 15 sec, in mesiodistal and occluso-apical directions, totaling 60 sec of irradiation with intervals of 10 sec between them; G3, Nd:YAG Laser+Gluma Desensitizer. The level of sensitivity to pain of each volunteer was analyzed by visual analog scale (VAS) using cold air stimuli and exploratory probe 5 min, 1 week, and 1, 3, and 6 months after treatment. Data were collected and subjected to statistical analysis that detected statistically significant differences between the various studied time intervals of treatments (p>0.05). Results: For the air stimulus, no significant differences were found for each time interval. For the long-term evaluation, all groups showed statistical differences (p>0.05), indicating that for G2 and G3, this difference was statistically significant from the first time of evaluation (post 1), whereas in G1, the difference was significant from the post 2 evaluation (1 week). Comparison among groups using the probe stimulation showed significant differences in pain (p<0.001). Only in G1 and G3 did this difference become significant from post 01. Conclusions: All protocols were effective in reducing dentinal hypersensitivity after 6 months of treatment; however, the association of Nd:YAG and Gluma Desensitizer is an effective treatment strategy that has immediate and long-lasting effects. PMID:23421629

Comparing the effectiveness of four desensitizing toothpastes on dentinal tubule occlusion: A scanning electron microscope analysis.

PubMed

Jena, Amit; Kala, Soumik; Shashirekha, Govind

2017-01-01

Dentin hypersensitivity (DH) is a sudden short sharp pain best explained by hydrodynamic theory. Several agents are available throughout the market that can treat DH either by blocking the nerves that helps in conducting pain or by blocking the open dentinal tubules. The aim of the present study was to compare the tubule occluding efficacy of four different desensitizing dentifrices under scanning electron microscope (SEM). Sixty-two dentin blocks measuring 5 mm × 5 mm × 3 mm were obtained from extracted human molar teeth and were randomly divided into five groups: Group 1 - no treatment (control, n = 2); Group 2 - Pepsodent Pro-sensitive relief and repair ( n = 15); Group 3 - Sensodyne repair and protect ( n = 15); Group 4 - Remin Pro ( n = 15); Group 5 - Test toothpaste containing 15% nano-hydroxyapatite (n-HA) crystals ( n = 15). The specimens were brushed for 2 min/day for 14 days and stored in artificial saliva. After final brushing, specimens were gold sputtered and viewed under SEM at ×2000 magnification. Results obtained were statistically analyzed using nonparametric Kruskal-Wallis test and least significant difference post hoc test. All test groups showed significant increase in dentin tubule occlusion as compared to control group. The highest percentage of tubules occluded was shown by Group 4 and Group 5 which was significantly different from other groups ( P ≤ 0.05), and there was no significant difference in tubule occlusion among them. Newer desensitizing dentifrices containing 15% n-HA and Remin Pro can provide effective tubule occlusion and thereby reduce the pain and discomfort caused by DH.

In vitro remineralization of enamel subsurface lesions and assessment of dentine tubule occlusion from NaF dentifrices with and without calcium.

PubMed

Prabhakar, A R; Manojkumar, A Jaiswal; Basappa, N

2013-01-01

Currently, fluoride is the most effective preventive treatment for remineralization of incipient carious lesions and dentinal hypersensitivity due to wasting disorders. The products containing fluoride, calcium and phosphate are also claim to remineralize early, non-cavitated enamel demineralization. The aim of this study was to investigate and compare the efficacy of two such products, Tooth Mousse and Clinpro tooth crème on remineralization and tubule occluding ability with 5000ppm fluoride-containing toothpaste. Thirty third molar teeth were placed in demineralizing solution for 5 days such that only a window of 1mm x 5mm was exposed to the environment to produce artificial caries-like lesions and randomly assigned to three groups: Group I, 5000ppm sodium fluoride; Group II, GC MI paste plus and Group III, Clinpro tooth crème. Axial longitudinal sections of 140-160 μm of each tooth which included the artificial carious lesion taken and were photographed under polarized light microscope. The demineralized areas were then quantified with a computerized imaging system. The experimental materials were applied onto the tooth sections as a topical coating and subjected to pH-cycling for 28 days. To evaluate tubule occlusion ability, thirty dentin specimens of 2mm thickness were obtained from cervical third of sound third molars. Specimens were ultrasonicated and etched with 6% citric acid for 2 minutes to simulate the hypersensitive dentin. Specimens were randomly divided into above mentioned three groups (n=10). The test agents were brushed over the specimens with an electric toothbrush, prepared and observed under Scanning Electron Microscope for calculation of the percentage of occluded tubules. Group I showed a significantly greater percentage of remineralization than Group III and Group II. Comparison of the remineralization potential between group II and group III were not significant.In case of dentine hypersensitivity, Group I and group III showed greater percentage of tubule occlusion ability than Group II. Intergroup comparison of the tubule occlusion potential of group I and group III were not significant. Within the limitations of our study, sodium fluoride showed relatively greatest remineralizing and dentinal tubule occlusion property when compared with GC MI paste plus and Clinpro tooth crème.

Management of Dentin Hypersensitivity by National Dental Practice-Based Research Network practitioners: results from a questionnaire administered prior to initiation of a clinical study on this topic.

PubMed

Kopycka-Kedzierawski, Dorota T; Meyerowitz, Cyril; Litaker, Mark S; Chonowski, Sidney; Heft, Marc W; Gordan, Valeria V; Yardic, Robin L; Madden, Theresa E; Reyes, Stephanie C; Gilbert, Gregg H

2017-01-13

Dentin hypersensitivity (DH) is a common problem encountered in clinical practice. The purpose of this study was to identify the management approaches for DH among United States dentists. One hundred eighty five National Dental Practice-Based Research Network clinicians completed a questionnaire regarding their preferred methods to diagnose and manage DH in the practice setting, and their beliefs about DH predisposing factors. Almost all dentists (99%) reported using more than one method to diagnose DH. Most frequently, they reported using spontaneous patient reports coupled with excluding other causes of oral pain by direct clinical examination (48%); followed by applying an air blast (26%), applying cold water (12%), and obtaining patient reports after dentist's query (6%). In managing DH, the most frequent first choice was desensitizing, over-the-counter (OTC), potassium nitrate toothpaste (48%), followed by fluorides (38%), and glutaraldehyde/HEMA (3%). A total of 86% of respondents reported using a combination of products when treating DH, most frequently using fluoride varnish and desensitizing OTC potassium nitrate toothpaste (70%). The most frequent predisposing factor leading to DH, as reported by the practitioners, was recessed gingiva (66%), followed by abrasion, erosion, abfraction/attrition lesions (59%) and bruxism (32%). The majority of network practitioners use multiple methods to diagnose and manage DH. Desensitizing OTC potassium nitrate toothpaste and fluoride formulations are the most widely used products to manage DH in dental practice setting.

Dentin and pulp sense cold stimulus.

PubMed

Tokuda, Masayuki; Tatsuyama, Shoko; Fujisawa, Mari; Morimoto-Yamashita, Yoko; Kawakami, Yoshiko; Shibukawa, Yoshiyuki; Torii, Mistuso

2015-05-01

Dentin hypersensitivity is a common symptom, and recent convergent evidences have reported transient receptor potential (TRP) channels in odontoblasts act as mechanical and thermal molecular sensor, which detect stimulation applied on the exposed dentin surface, to drive multiple odontoblastic cellular functions, such as sensory transduction and/or dentin formation. In the present study, we confirmed expression of TRP melastatin subfamily member-8 (TRPM8) channels in primary cultured cells derived from human dental pulp cells (HPCs) and mouse odontoblast-lineage cells (OLCs) as well as in dentin matrix protein-1 (DMP-1) and dentin sialoprotein (DSP) positive acutely isolated rat odontoblasts from dental pulp tissue slice culture by immunohistochemical analyses. In addition, we detected TRPM8 channel expression on HPCs and OLCs by RT-PCR and Western blotting analyses. These results indicated that both odontoblasts and dental pulp cells express TRPM8 channels in rat, mouse and human, and therefore we hypothesize they may contribute as cold sensor in tooth. Copyright © 2015 Elsevier Ltd. All rights reserved.

Microleakage in Class V Composite Restorations after Desensitizing Surface Treatment with Er:YAG and CO2 Lasers.

PubMed

Mozaffari, Hamid Reza; Ehteshami, Alireza; Zallaghi, Farshad; Chiniforush, Nasim; Moradi, Zohreh

2016-12-30

Aims: Glutaraldehyde, CO 2 and Er:YAG lasers can be used for treatment of dentin hypersensitivity. However, their application may have adverse effects on the clinical service of restorations. This study aimed to assess the microleakage in composite restorations following surface treatment with Glutaraldehyde desensitizer, CO 2 and Er:YAG laser irradiation for treatment of dentin hypersensitivity. Materials and methods: This experimental study was conducted on 60 extracted sound human teeth. Class V cavities were prepared measuring 3×3 mm using a diamond bur. Specimens were randomly divided into 4 groups of 15. Group one:no surface treatment, Group two:applying Glutaraldehyde desensitizer, Groups of three and four were irradiated with CO 2 and Er:YAG lasers, respectively. Surfaces were restored with bonding agent (Single Bond 2, 3M, USA) and Z250 composite (3M, USA). Specimens were thermocycled and immersed in 1% methylene blue solution for 24 hours. Microleakage scores were assessed under a stereomicroscope at ×20 magnification. Data were analyzed using SPSS and the Kruskal Wallis test (P=0.05). Results: There was no significant difference between microleakage of groups in enamel margins (P=0.694). The difference in microleakage at the dentin margin was significant between groups (P=0.018). Conclusions: Application of Glutaraldehyde-desensitizer and CO 2 laser irradiation of surfaces prior to composite restoration do not increase microleakage at the enamel or dentin margins but tooth surface treatment with Er:YAG laser significantly increased the microleakage at the dentin margins.

Dentin abrasivity of various desensitizing toothpastes.

PubMed

Arnold, W H; Gröger, Ch; Bizhang, M; Naumova, E A

2016-04-02

The aim of this study was to compare the abrasivity of various commercially available toothpastes that claim to reduce dentin hypersensitivity. Dentin discs were prepared from 70 human extracted molars. The discs were etched with lemon juice for 5 min, and one half of the discs were covered with aluminum tape. Following this, they were brushed with 6 different toothpastes, simulating a total brushing time of 6 months. As a negative control, discs were brushed with tap water only. The toothpastes contained pro-arginine and calcium carbonate, strontium acetate, stannous fluoride, zinc carbonate and hydroxyapatite, new silica, or tetrapotassium pyrophosphate and hydroxyapatite. After brushing, the height differences between the control halves and the brushed halves were determined with a profilometer and statistically compared using a Mann-Whitney U test for independent variables. A significant difference (p < 0.001) in height difference between the controls and the toothpaste-treated samples was found in all cases, except for the stannous fluoride-containing toothpaste (p = 0.583). The highest abrasion was found in the toothpaste containing zinc carbonate and hydroxyapatite, and the lowest was found in the toothpaste containing pro-arginine and calcium carbonate. Desensitizing toothpastes with different desensitizing ingredients have different levels of abrasivity, which may have a negative effect on their desensitizing abilities over a long period of time.

Comparing the effect of a desensitizing material and a self-etch adhesive on dentin sensitivity after periodontal surgery: a randomized clinical trial

PubMed Central

Hajizadeh, Hila; Majidinia, Sara; Moeintaghavi, Amir; Ghavamnasiri, Marjaneh

2017-01-01

Objectives This double-blind randomized placebo-controlled clinical trial evaluated the ability of a desensitizing agent and a self-etch adhesive on cervical dentin sensitivity (CDS) after periodontal surgery. Materials and Methods Ninety hypersensitive teeth of 13 subjects were included in the study. After periodontal surgery, the teeth of each posterior sextant treated with one of the following materials: G1: Clearfil S3 Bond (Kuraray Dental), G2: Gluma Desensitizer (Heraeus Kulzer), and G3: placebo (water). The sensitivity was assessed using evaporative stimuli before treatment (baseline, T0), 1 day after treatment (T1), after 1 week (T2), and after 1 month (T3) according to visual analog scale (VAS). Results Following the treatment, all the 3 groups showed significant reduction of CDS in T1 compared to T0. Reduction of CDS between T1 and T2 was observed only in G1 but there was no significant difference between T2 and T3 in this group. Although we observed a significant difference in T3 compared to T1 and T2 in G2 and G3, comparison of treatment groups in each assessment time showed a significant difference only in T3. According to paired comparison, this was due to the difference between G2 and G3. Conclusions Dentin sensitivity following periodontal surgery will decrease spontaneously over time, but treating the sensitive teeth with Gluma Desensitizer and Clearfil S3 Bond can have some benefits. PMID:28808633

Effects of desensitizing toothpastes on the permeability of dentin after different brushing times: An in vitro study.

PubMed

Yang, Meng; Lin, Hong; Jiang, Ruodan; Zheng, Gang

2016-12-01

To investigate the effects of three commercially available desensitizing toothpastes on dentin permeability, and compare the efficacy of each product for reducing dentin permeability in the short term according to the frequency and duration of usage. 100 dentin discs with no caries were prepared from freshly extracted human third molar teeth. The dentin discs were brushed with three desensitizing toothpastes or with a non-desensitizing toothpaste and distilled water, which served as control. The 100 dentin slices were randomly divided into two groups (n= 50): one group underwent continuous brushing (brushed for 3 minutes continuously), and the other group underwent discontinuous brushing (brushed three times, each time for 1 minute). Then, the two groups were divided into five subgroups (n = 10) for the five brushing applications. Dentin permeability was measured with a hydraulic permeability system before and after brushing. All desensitizing toothpastes reduced dentin permeability significantly after treatment. Sensodyne Repair and Protect (calcium sodium phosphosilicate) and discontinuous brushing reduced dentin permeability significantly compared with continuous brushing. Dentin permeability values showed no significant difference between the three toothpastes after 3 minutes of continuous brushing. When comparing the three toothpastes under discontinuous brushing conditions after 3 minutes, Sensodyne Repair and Protect (calcium sodium phosphosilicate) reduced dentin permeability significantly. Sensodyne Repair and Protect (calcium sodium phosphosilicate) and discontinuous brushing reduced dentin permeability significantly compared with continuous brushing. Moreover, brushing with Sensodyne Repair and Protect (calcium sodium phosphosilicate) resulted in the lowest dentin permeability compared with those of the other two toothpastes. These results indicated that Sensodyne Repair and Protect may relieve dentin hypersensitivity.

Synthesis of Calcium Phosphate Composite Organogels by Using Emulsion Method for Dentine Occlusion Materials

NASA Astrophysics Data System (ADS)

Nopteeranupharp, C.; Akkarachaneeyakorn, K.; Songsasaen, A.

2018-03-01

Dentinal hypersensitivity (DH) is one of the most human’s problems caused by the erosion of enamel. There are many methods and materials to solve this problem. Calcium phosphate is an excellent alternative for curing this symptom because of its osteoconductivity, and biocompatibility properties. The low-cost and low-toxicity calcium phosphate nanogel was fabricated by using emulsion method and characterized by using TEM, EDX, and DLS techniques. The results showed that P123 (poly (ethylene oxide)19-block-Poly (propylene oxide)69-block-poly (ethylene oxide)19) has played a major role as template and gel formation, SDS was used as a surfactant to form water-in-oil emulsion nanodroplets with circle-like shape. Moreover, the ability of synthesised organogel to occlude the exposed dentine tubules was tested on the model of human’s dentine slices. The results showed that calcium phosphate composite organogel can be efficiently occluded on dentine slice, characterized by SEM technique, after 1 day.

Surface roughness and bacterial adhesion on root dentin treated with diode laser and conventional desensitizing agents.

PubMed

Cury, Maiza S; Silva, Camilla B; Nogueira, Ruchele D; Campos, Michelle G D; Palma-Dibb, Regina G; Geraldo-Martins, Vinicius R

2018-02-01

The treatments for dentin hypersensitivity (DH) may change the surface roughness of the root dentin, which can lead to biofilm accumulation, increasing the risk of root caries. The aim was to compare the surface roughness of root dentin after different treatments of DH and the biofilm formation on those surfaces. After initial surface roughness (Sa) assessment, 50 bovine root fragments received the following treatments (n = 10): G 1-no treatment; G2-5% sodium fluoride varnish; G3-professional application of a desensitizing dentifrice; G4-toothbrushing with a desensitizing dentifrice; and G5-diode laser application (908 nm; 1.5 W, 20 s). The Sa was reevaluated after treatments. Afterward, all samples were incubated in a suspension of Streptococcus mutans at 37 °C for 24 h. The colony-forming units (CFU) were counted using a stereoscope, and the results were expressed in CFU/mL. The one-way ANOVA and the Tukey's tests compared the roughness data and the results obtained on the bacterial adhesion test (α = 5%). G2 (2.3 ± 1.67%) showed similar Sa variation than G1 (0.25 ± 0.41%) and G5 (5.69 ± 0.99%), but different from group G3 (9.05 ± 2.39%). Group 4 showed the highest Sa variation (30.02 ± 3.83%; p < 0.05). Bacterial adhesion was higher in G4 (2208 ± 211.9), suggesting that bacterial growth is greater on rougher surfaces. The diode laser and the conventional treatments for DH may change the surface roughness of the root dentin, but only brushing with desensitizing dentifrice induced a higher bacteria accumulation on root dentin surface.

An evaluation of smear layer with various desensitizing agents after tooth preparation.

PubMed

Zaimoglu, A; Aydin, A K

1992-09-01

According to hydrodynamics, any agent blocking the dentinal tubules reduces the flow of fluids and diminishes hypersensitivity. The properties of the desensitizing agents that sponsor tubular occlusion and the barrier efficiency resulting from the interaction of the smear layer with test materials were examined with the scanning electron microscope and energy-dispersive x-ray microanalysis. Selected dentinal desensitizing was accomplished with burnishing procedures, cavity varnish, calcium hydroxide, and topical fluoride. Subjective evaluations were also recorded clinically after tooth preparation. This investigation indicated that the smear layer did not protect against zinc phosphate cement, and that cavity varnish prevented the formation of the smear plugs. The smear layer and plugs were basically composed of calcium and phosphorus, the major ingredients of dentin.

Fluoride rinse effect on retention of CaF2 formed on enamel/dentine by fluoride application.

PubMed

Falcão, Amanda; Masson, Nadia; Leitão, Tarcísio Jorge; Botelho, Juliana Nunes; Ferreira-Nóbilo, Naiara de Paula; Tabchoury, Cínthia Pereira Machado; Tenuta, Livia Maria Andaló; Cury, Jaime Aparecido

2016-01-01

Calcium fluoride-like materials ("CaF2") formed on dental surfaces after professional fluoride application are unstable in the oral environment but can be retained longer with a daily NaF mouthrinse. We tested the effect of twice daily 0.05% NaF rinses on the retention of "CaF2" formed on enamel and dentine after applying acidulated phosphate fluoride (APF). "CaF2" formed on enamel/dentine by APF application significantly decreased after exposure to artificial saliva and the 0.05% NaF rinse was ineffective to avoid this reduction. These findings suggest that the combination of APF and 0.05% NaF is not clinically relevant, either for caries or dental hypersensitivity.

Structural changes in the irradiated dentin with Nd:YAG and Er:YAG lasers for cervical hypersensitivity treatment and their influence on the microtensile resistance in resin-dentin interface

NASA Astrophysics Data System (ADS)

Mota, Cláudia C. B. O.; Sena, Tatiane V. N. S.; Castro, Roseane F.; Araújo, Ana C. S.; Gomes, Anderson S. L.

2016-02-01

This study aimed to evaluate, in vitro, the structural changes in dentin surfaces irradiated with Er:YAG (2940 nm, 90 mJ, 2 Hz, 300 μs, spot diameter 0.9 mm, 60 s/cm2, using the handpiece at 6 cm of distance to surface) and Nd:YAG (1064 nm, 1 W, 10 Hz, 300 μs, optical fiber diameter 300 μm, 60 s/cm2, using the handpiece at 2 mm of distance to surface) lasers to the treatment of cervical hypersensitivity and the respective bond strength compromising of resin composite restorations over these surfaces. 45 bovine teeth were selected, and removed the enamel portion of the buccal surface for laser irradiation and restorative procedure. Samples were divided into three groups: G1: control, only fluoride therapy; G2: irradiated with Er:YAG laser; G3: irradiated with Nd:YAG laser. Samples were submitted to optical coherence tomography analysis and subsequently they were restored with resin composite and sectioned into sticks for microtensile tests of achievement. ANOVA analysis of variance for the maximum force (N) and strength (MPa), with a significance level of 5% was performed. It was observed that G3 presented lower performance of maximum force (38,8 +/- 11,3 N) and resistance (26,0 +/- 9,3 MPa), and the G2 presented better results (51,0 +/- 13,5 N and 36,5 +/- 10,1 MPa), but still lower than those one obtained for G1 (56,0 +/- 12,3 N and 43,5 +/- 8,6 MPa). Although both lasers are effective in the cervical hypersensitivity treatment, when the aesthetic factor is the priority, the use of Er:YAG is preferable.

Effect of surface protection on the permeability of eroded dentin

PubMed Central

Martins, Vivian Leite; da Costa Ramos, Rodrigo Vitoria; Pimenta Lima, Max José; Correia de Araújo, Roberto Paulo; Cavalcanti, Andrea Nóbrega

2018-01-01

Context: Eroded dentin might present the opening of dentinal tubules, increasing permeability, and consequently dentinal hypersensitivity. Aims: This study evaluated the permeability of dentin surfaces exposed to different levels of erosion and methods of surface protection. Materials and Methods: Dentine samples (3 mm × 3 mm × 1 mm) were prepared from bovine incisors (n = 90) and divided into three groups according to the method of controlling erosive challenge: Negative control, topical fluoride application, and glass ionomer sealant. Subsequently, they were randomly divided into three subgroups according to the exposure of simulated gastric acid solution (Demineralization – DES) (5% HCl, pH = 2.2), and remineralization (RE); negative control, 9 and 18 cycles DES-RE. The dentin permeability was measured by assessing the hydraulic conductance (μl/min.cmH2O.cm2). Statistical analysis was performed by two-way ANOVA and Tukey's test. Results and Conclusions: Greater permeability was observed after 18 erosive cycles, followed by exposure to 9 cycles and negative control (P < 0.0001). The application of glass ionomer sealant resulted in a major reduction of the hydraulic conductivity, regardless of the erosive challenge. Control groups and topical fluoride application showed similar results. In conclusion, the severity of erosive challenge contributed to the increase of dentin permeability. Besides, the glass ionomer sealant was the only protection agent that promoted significant effects in dentin permeability. PMID:29628641

Penetration of sub-micron particles into dentinal tubules using ultrasonic cavitation.

PubMed

Vyas, N; Sammons, R L; Pikramenou, Z; Palin, W M; Dehghani, H; Walmsley, A D

2017-01-01

Functionalised silica sub-micron particles are being investigated as a method of delivering antimicrobials and remineralisation agents into dentinal tubules. However, their methods of application are not optimised, resulting in shallow penetration and aggregation. The aim of this study is to investigate the impact of cavitation occurring around ultrasonic scalers for enhancing particle penetration into dentinal tubules. Dentine slices were prepared from premolar teeth. Silica sub-micron particles were prepared in water or acetone. Cavitation from an ultrasonic scaler (Satelec P5 Newtron, Acteon, France) was applied to dentine slices immersed inside the sub-micron particle solutions. Samples were imaged with scanning electron microscopy (SEM) to assess tubule occlusion and particle penetration. Qualitative observations of SEM images showed some tubule occlusion. The particles could penetrate inside the tubules up to 60μm when there was no cavitation and up to ∼180μm when there was cavitation. The cavitation bubbles produced from an ultrasonic scaler may be used to deliver sub-micron particles into dentine. This method has the potential to deliver such particles deeper into the dentinal tubules. Cavitation from a clinical ultrasonic scaler may enhance penetration of sub-micron particles into dentinal tubules. This can aid in the development of novel methods for delivering therapeutic clinical materials for hypersensitivity relief and treatment of dentinal caries. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of Dentifrice Containing Hydroxyapatite on Dentinal Tubule Occlusion and Aqueous Hexavalent Chromium Cations Sorption: A Preliminary Study

PubMed Central

Liu, Jing; Hou, Yarong; Zhu, Manqun; Huang, Jiansheng; Xu, Pingping

2012-01-01

In order to endow environmental protection features to dentifrice, hydroxyapatite (HA) was added to ordinary dentifrice. The effects on dentinal tubule occlusion and surface mineralization were compared after brushing dentine discs with dentifrice with or without HA. The two types of dentifrice were then added to 100 µg/ml of hexavalent chromium cation (Cr6+) solution in order to evaluate their capacities of adsorbing Cr6+ from water. Our results showed that the dentifrice containing HA was significantly better than the ordinary dentifrice in occluding the dentinal tubules with a plugging rate greater than 90%. Moreover, the effect of the HA dentifrice was persistent and energy-dispersive spectrometer (EDS) revealed that the atomic percentages of calcium and phosphorus on the surface of dentine discs increased significantly. Adding HA to ordinary dentifrice significantly enhanced the ability of dentifrice to adsorb Cr6+ from water with the removal rate up to 52.36%. In addition, the sorption was stable. Our study suggests that HA can be added to ordinary dentifrice to obtain dentifrice that has both relieving dentin hypersensitivity benefits and also helps to control environmental pollution. PMID:23300511

Mathematical simulation of the thermal diffusion in dentine irradiated with Nd:YAG laser using finite difference method

NASA Astrophysics Data System (ADS)

Moriyama, Eduardo H.; Zangaro, Renato A.; Lobo, Paulo D. d. C.; Villaverde, Antonio G. J. B.; Watanabe-Sei, Ii; Pacheco, Marcos T. T.; Otsuka, Daniel K.

2002-06-01

Thermal damage in dental pulp during Nd:YAG laser irradiation have been studied by several researchers; but due to dentin inhomogeneous structure, laser interaction with dentin in the hypersensitivity treatment are not fully understood. In this work, heat distribution profile on human dentine samples irradiated with Nd:YAG laser was simulated at surface and subjacent layers. Calculations were carried out using the Crank-Nicolson's finite difference method. Sixteen dentin samples with 1,5 mm of thickness were evenly distributed into four groups and irradiated with Nd:YAG laser pulses, according to the following scheme: (I) 1 pulse of 900 mJ, (II) 2 pulses of 450 mJ, (III) 3 pulses of 300 mJ, (IV) 6 pulses of 150 mJ; corresponding to a total laser energy of 900 mJ. The pulse interval was 300ms, the pulse duration of 900 ms and irradiated surface area of 0,005 mm2. Laser induced morphological changes in dentin were observed for all the irradiated samples. The heat distribution throughout the dentin layer, from the external dentin surface to the pulpal chamber wall, was calculated for each case, in order to obtain further information about the pulsed Nd:YAG laser-oral hard tissue interaction. The simulation showed significant differences in the final temperature at the pulpal chamber, depending on the exposition time and the energy contained in the laser pulse.

Evaluation of desensitizing agents on dentin permeability and dentinal tubule occlusion: an in vitro study.

PubMed

Oberg, Carolina; Pochapski, Marcia Thais; Farago, Paulo Vitor; Granado, Carlos Jose Fernandes; Pilatti, Gibson Luiz; Santos, Fabio Andre

2009-01-01

One hundred twelve specimens from bovine incisors were divided into eight groups: Group 1 (treated with 10% strontium chloride gel), Group 2 (treated with 2% sodium fluoride gel), Group 3 (treated with 2% stannous fluoride gel), Group 4 (treated with 5% potassium nitrate gel), Group 5 (treated with 10% potassium nitrate gel), Group 6 (treated with 3% potassium oxalate gel), Group 7 (treated with hydroxyethylcellulose gel), and Group 8 (which received no treatment). Dentinal tubules were exposed after 0.5 mm of deep abrasion using a carbide bur and EDTA gel application. After each treatment, dentin permeability, tubule occlusion, and chemical elements on dentin were analyzed. There was a significant difference among groups in dentin permeability (p < 0.05 ANOVA). Groups 4, 5, and 6 showed the lowest values, while Groups 1, 7, and 8 exhibited the highest. Groups 1, 2, 3, 7, and 8 showed open dentinal tubules, Groups 4 and 5 had partial tubule occlusion, and most of the tubules in Group 6 were obliterated. Energy-dispersive x-rays revealed similar chemical characteristics among the experimental agents used, with traces of strontium, fluoride, sodium, and potassium. Within the limits of the study, 3% potassium oxalate gel showed the best results in terms of dentin permeability and dentinal tubule occlusion.

Effectiveness of a resin-modified glass ionomer liner in reducing hypersensitivity in posterior restorations: a study from the practitioners engaged in applied research and learning network.

PubMed

Strober, Brad; Veitz-Keenan, Analia; Barna, Julie Ann; Matthews, Abigail G; Vena, Donald; Craig, Ronald G; Curro, Frederick A; Thompson, Van P

2013-08-01

The objectives of this randomized comparative effectiveness study conducted by members of the Practitioners Engaged in Applied Research and Learning (PEARL) Network were to determine whether using a resin-modified glass ionomer (RMGI) liner reduces postoperative hypersensitivity (POH) in dentin-bonded Class I and Class II resin-based composite (RBC) restorations, as well as to identify other factors (putative risk factors) associated with increased POH. PEARL Network practitioner-investigators (P-Is) (n = 28) were trained to assess sensitivity determination, enamel and dentin caries activity rankings, evaluation for sleep bruxism, and materials and techniques used. The P-Is enrolled 341 participants who had hypersensitive posterior lesions. Participants were randomly assigned to receive an RBC restoration with or without an RMGI liner before P-Is applied a one-step, self-etching bonding agent. P-Is conducted sensitivity evaluations at baseline, at one and four weeks after treatment, and at all visits according to patient-reported outcomes. P-Is collected complete data regarding 347 restorations (339 participants) at baseline, with 341 (98 percent) (333 participants) recalled at four weeks. Treatment groups were balanced across baseline characteristics and measures. RBC restorations with or without an RMGI liner had the same one-week and four-week POH outcomes, as measured clinically (by means of cold or air stimulation) and according to patient-reported outcomes. Use of an RMGI liner did not reduce clinically measured or patient-reported POH in moderate-depth Class I and Class II restorations. Cold and air clinical stimulation findings were similar between groups. Practical Implications. The time, effort and expense involved in placing an RMGI liner in these moderate-depth RBC restorations may be unnecessary, as the representative liner used did not improve hypersensitivity outcomes.

Efficacy of an experimental toothpaste containing 5% calcium sodium phosphosilicate in the relief of dentin hypersensitivity: An 8-week randomized study (Study 2).

PubMed

Sufi, Farzana; Hall, Claire; Mason, Stephen; Shaw, David; Milleman, Jeffery; Milleman, Kimberly

2016-04-01

To compare the efficacy of an experimental toothpaste containing 5% (w/w) calcium sodium phosphosilicate (CSPS) in relieving dentin hypersensitivity (DH) with that of control toothpastes containing no known anti-sensitivity ingredients. This was the second of two exploratory, randomized, four-treatment, examiner-blind, parallel-design, single-site, 8-week studies in healthy subjects with self-reported and clinically diagnosed DH. After an initial lead-in period, subjects were randomized to one of four study treatments: the experimental toothpaste containing 5% CSPS with a modified surfactant system, developed to enhance its organoleptic properties; an abrasivity-matched placebo formulation (0% CSPS) with additional abrasive silica replacing the CSPS; or one of two commercially available fluoride toothpastes as controls. Subjects were instructed to brush twice daily for the next 8 weeks. DH was assessed at baseline and following 4 and 8 weeks of treatment by response to tactile and evaporative (air) stimuli, and using a Dentine Hypersensitivity Experience Questionnaire (DHEQ; a validated quality of life measure for DH). A total of 137 subjects were included in the efficacy analysis. The experimental 5% CSPS toothpaste demonstrated statistically significant reductions from baseline in sensitivity at Week 4 and Week 8 for each clinical measure (all P< 0.01). It also demonstrated significantly greater improvements in DH compared with the two control toothpastes for the majority of clinical measures at Week 4 (P ≤ 0.01) and for all clinical measures at Week 8 (all P < 0.01). The abrasivity-matched 0% CSPS toothpaste was associated with similar outcomes to the 5% CSPS toothpaste. The DHEQ responses did not reveal any consistent statistically significant within-treatment changes from baseline or between-treatment differences. Strong correlations with DHEQ outcomes were only observed for the subjects' sensitivity rating in response to evaporative (air) stimuli at Week 8. Study treatments were well tolerated.

Resin–dentin bonds to EDTA-treated vs. acid-etched dentin using ethanol wet-bonding

PubMed Central

Sauro, Salvatore; Toledano, Manuel; Aguilera, Fatima Sánchez; Mannocci, Francesco; Pashley, David H.; Tay, Franklin R.; Watson, Timothy F.; Osorio, Raquel

2013-01-01

Objective To compare resin–dentin bond strengths and the micropermeability of hydrophobic vs. hydrophilic resins bonded to acid-etched or EDTA-treated dentin, using the ethanol wet-bonding technique. Methods Flat dentin surfaces from extracted human third molars were conditioned before bonding with: 37% H3PO4 (15 s) or 0.1 M EDTA (60 s). Five experimental resin blends of different hydrophilicities and one commercial adhesive (SBMP: Scotchbond Multi-Purpose) were applied to ethanol wet-dentin (1 min) and light-cured (20 s). The solvated resins were used as primers (50% ethanol/50% comonomers) and their respective neat resins were used as the adhesive. The resin-bonded teeth were stored in distilled water (24 h) and sectioned in beams for microtensile bond strength testing. Modes of failure were examined by stereoscopic light microscopy and SEM. Confocal tandem scanning microscopy (TSM) interfacial characterization and micropermeability were also performed after filling the pulp chamber with 1 wt% aqueous rhodamine-B. Results The most hydrophobic resin 1 gave the lowest bond strength values to acid-etched dentin and all beams failed prematurely when the resin was applied to EDTA-treated dentin. Resins 2 and 3 gave intermediate bond strengths to both conditioned substrates. Resin 4, an acidic hydrophilic resin, gave the highest bond strengths to both EDTA-treated and acid-etched dentin. Resin 5 was the only hydrophilic resin showing poor resin infiltration when applied on acid-etched dentin. Significance The ethanol wet-bonding technique may improve the infiltration of most of the adhesives used in this study into dentin, especially when applied to EDTA-treated dentin. The chemical composition of the resin blends was a determining factor influencing the ability of adhesives to bond to EDTA-treated or 37% H3PO4 acid-etched dentin, when using the ethanol wet-bonding technique in a clinically relevant time period. PMID:20074787

Efficacy of an experimental toothpaste containing 5% calcium sodium phosphosilicate in the relief of dentin hypersensitivity: An 8-week randomized study (Study 1).

PubMed

Sufi, Farzana; Hall, Claire; Mason, Stephen; Shaw, David; Kennedy, Liam; Gallob, John T

2016-04-01

To evaluate the efficacy of an experimental toothpaste containing 5% (w/w) calcium sodium phosphosilicate (CSPS) in relieving dentin hypersensitivity (DH) compared with control toothpastes containing no known anti-sensitivity ingredients. This was the first of two exploratory, randomized, four-treatment, examiner-blind, parallel-design, single-site, 8-week studies in healthy subjects with self-reported and clinically diagnosed DH. The experimental toothpaste contained 5% CSPS with a modified surfactant system, developed to enhance its organoleptic properties. Efficacy was evaluated against an abrasivity-matched placebo formulation (0% CSPS) with additional abrasive silica replacing the CSPS, and two commercially available fluoride toothpastes as controls. After an initial lead-in period, subjects were randomized to one of the four study treatments and instructed to brush twice daily for the next 8 weeks. DH was assessed at baseline and following 4 and 8 weeks of treatment by response to tactile and evaporative (air) stimuli, and using a Dentine Hypersensitivity Experience Questionnaire (DHEQ; a validated quality-of-life measure for DH). A total of 134 subjects were randomized and completed the study. All treatments demonstrated statistically significant reductions in sensitivity from baseline at Week 4 and Week 8 for each clinical measure of sensitivity (all P ≤ 0.001). The 0% CSPS toothpaste demonstrated small but statistically significant reductions in Schiff sensitivity score compared with the other study toothpastes at Week 8 (all P< 0.05), whereas the experimental 5% CSPS toothpaste significantly improved the tactile threshold at Week 4 compared with the 0% CSPS toothpaste (P = 0.0467). The DHEQ responses did not reveal any consistent statistically significant within-treatment changes from baseline or between-treatment differences. Correlation analysis showed weak-to-moderate associations between the DHEQ outcomes and clinical endpoints. Study treatments were well tolerated. The treatment differences observed in this exploratory study were small and inconsistent between measures. The reasons for the inconsistencies are not clear but may be related to the properties of the abrasivity-matched 0% CSPS formulation, with the increased level of dental silica conferring an advantage in terms of reducing DH. The ability of dental silicas to occlude exposed dentin tubules and thereby reduce DH has been demonstrated in previous studies, and may warrant further clinical investigation.

Mechanical characterization of proanthocyanidin-dentin matrix interaction

PubMed Central

Castellan, Carina Strano; Pereira, Patricia Nobrega; Grande, Rosa Helena Miranda; Bedran-Russo, Ana Karina

2010-01-01

Objectives To characterize the properties of dentin matrix treated with two proanthocyanidin rich cross-linking agents and their effect on dentin bonded interfaces. Methods Sound human molars were cut into 0.5 mm thick dentin slabs, demineralized and either treated with one of two cross-linking agents (grape seed - GSE and cocoa seed - COE extracts) or left untreated. The modulus of elasticity of demineralized dentin was assessed after 10 or 60 min and the swelling ratio after 60 min treatment. Bacterial collagenase was also used to assess resistance to enzymatic degradation of samples subjected to ultimate tensile strength. The effect of GSE or COE on the resin-dentin bond strength was evaluated after 10 or 60 min of exposure time. Data were statistically analyzed at a 95% confidence interval. Results Both cross-linkers increased the elastic modulus of demineralized dentin as exposure time increased. Swelling ratio was lower for treated samples when compared to control groups. No statistically significant changes to the UTS indicate that collagenase had no effect on dentin matrix treated with either GSE or COE. Dentin-resin bonds significantly increased following treatment with GSE regardless of the application time or adhesive system used. Significance Increased mechanical properties and stability of dentin matrix can be achieved by the use of PA-rich collagen cross-linkers most likely due to the formation of a PA-collagen complex. The short term dentin-resin bonds can be improved after 10 minutes dentin treatment. PMID:20650510

Resin-dentin bonds to EDTA-treated vs. acid-etched dentin using ethanol wet-bonding. Part II: Effects of mechanical cycling load on microtensile bond strengths.

PubMed

Sauro, Salvatore; Toledano, Manuel; Aguilera, Fatima Sánchez; Mannocci, Francesco; Pashley, David H; Tay, Franklin R; Watson, Timothy F; Osorio, Raquel

2011-06-01

To compare microtensile bond strengths (MTBS) subsequent to load cycling of resin bonded acid-etched or EDTA-treated dentin using a modified ethanol wet-bonding technique. Flat dentin surfaces were obtained from extracted human molars and conditioned using 37% H(3)PO(4) (PA) (15s) or 0.1M EDTA (60s). Five experimental adhesives and one commercial bonding agent were applied to the dentin and light-cured. Solvated experimental resins (50% ethanol/50% comonomers) were used as primers and their respective neat resins were used as the adhesives. The resin-bonded teeth were stored in distilled water (24h) or submitted to 5000 loading cycles of 90N. The bonded teeth were then sectioned in beams for MTBS. Modes of failure were examined by scanning electron microscopy. The most hydrophobic resin 1 gave the lowest bond strength values to both acid and EDTA-treated dentin. The hydrophobic resin 2 applied to EDTA-treated dentin showed lower bond strengths after cycling load but this did not occur when it was bonded to PA-etched dentin. Resins 3 and 4, which contained hydrophilic monomers, gave higher bond strengths to both EDTA-treated or acid-etched dentin and showed no significant difference after load cycling. The most hydrophilic resin 5 showed no significant difference in bond strengths after cycling loading when bonded to EDTA or phosphoric acid treated dentin but exhibited low bond strengths. The presence of different functional monomers influences the MTBS of the adhesive systems when submitted to cyclic loads. Adhesives containing hydrophilic comonomers are not affected by cycling load challenge especially when applied on EDTA-treated dentin followed by ethanol wet bonding. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Dentin surface treatment using a non-thermal argon plasma brush for interfacial bonding improvement in composite restoration

PubMed Central

Ritts, Andy Charles; Li, Hao; Yu, Qingsong; Xu, Changqi; Yao, Xiaomei; Hong, Liang; Wang, Yong

2010-01-01

The objective of this study is to investigate the treatment effects of non-thermal atmospheric gas plasmas on dentin surfaces for composite restoration. Extracted unerupted human third molars were used by removing the crowns and etching the exposed dentin surfaces with 35% phosphoric acid gel. The dentin surfaces were treated by using a non-thermal atmospheric argon plasma brush for various durations. The molecular changes of the dentin surfaces were analyzed using FTIR/ATR and an increase in carbonyl groups on dentin surfaces was detected with plasma treated dentin. Adper Single Bond Plus adhesive and Filtek Z250 dental composite were applied as directed. To evaluate the dentin/composite interfacial bonding, the teeth thus prepared were sectioned into micro-bars as the specimens for tensile test. Student Newman Keuls tests showed that the bonding strength of the composite restoration to peripheral dentin was significantly increased (by 64%) after 30 s plasma treatment. However, the bonding strength to plasma treated inner dentin did not show any improvement. It was found that plasma treatment of peripheral dentin surface up to 100 s gave an increase in interfacial bonding strength, while a prolong plasma treatment of dentin surfaces, e.g., 5 min treatments, showed a decrease in interfacial bonding strength. PMID:20831586

Effects of Er:YAG laser irradiation on human dentin: polarizing microscopic, light microscopic and microradiographic observations, and FT-IR analysis.

PubMed

Ishizaka, Yaeko; Eguro, Toru; Maeda, Toru; Tanaka, Hisayoshi

2002-01-01

The effects of Er:YAG laser irradiation on dentin have not been sufficiently investigated. The purpose of this study was to investigate the effects of Er:YAG laser irradiation on dentin. After cavities were prepared using Er:YAG laser irradiation or rotary cutting instruments, histological observations of cavity-floor dentin utilizing polarizing microscopy, microradiography and light microscopy, and analysis of composition of cavity-floor dentin using Fourier-transformed (FT-IR) spectrometry were conducted. In the laser-treated side, a deeply stained basophilic layer was observed. The number of odontoblastic processes present was obviously less in the laser-treated side than in the bur-treated side. FT-IR analysis revealed that compared to the bur-treated side, a broad background peak at around 1,600 cm(-1) was present. Er:YAG laser irradiation might have denatured the organic materials of dentin. Copyright 2002 Wiley-Liss, Inc.

EDTA conditioning of dentine promotes adhesion, migration and differentiation of dental pulp stem cells.

PubMed

Galler, K M; Widbiller, M; Buchalla, W; Eidt, A; Hiller, K-A; Hoffer, P C; Schmalz, G

2016-06-01

To evaluate the effect of dentine conditioning on migration, adhesion and differentiation of dental pulp stem cells. Dentine discs prepared from extracted human molars were pre-treated with EDTA (10%), NaOCl (5.25%) or H2 O. Migration of dental pulp stem cells towards pre-treated dentine after 24 and 48 h was assessed in a modified Boyden chamber assay. Cell adhesion was evaluated indirectly by measuring cell viability. Expression of mineralization-associated genes (COL1A1, ALP, BSP, DSPP, RUNX2) in cells cultured on pre-treated dentine for 7 days was determined by RT-qPCR. Nonparametric statistical analysis was performed for cell migration and cell viability data to compare different groups and time-points (Mann-Whitney U-test, α = 0.05). Treatment of dentine with H2 O or EDTA allowed for cell attachment, which was prohibited by NaOCl with statistical significance (P = 0.000). Furthermore, EDTA conditioning induced cell migration towards dentine. The expression of mineralization-associated genes was increased in dental pulp cells cultured on dentine after EDTA conditioning compared to H2 O-pre-treated dentine discs. EDTA conditioning of dentine promoted the adhesion, migration and differentiation of dental pulp stem cells towards or onto dentine. A pre-treatment with EDTA as the final step of an irrigation protocol for regenerative endodontic procedures has the potential to act favourably on new tissue formation within the root canal. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Effect of dentin etching and chlorhexidine application on metalloproteinase-mediated collagen degradation

PubMed Central

Raquel, Osorio; Mónica, Yamauti; Estrella, Osorio; Estrella, Ruiz-Requena María; David, Pashley; Franklin, Tay; Manuel, Toledano

2013-01-01

Dentin matrix metalloproteinases (MMPs) are involved in collagen degradation of resin-dentin interfaces. This study evaluated if collagen degradation can be prevented by chlorhexidine after different dentin demineralization procedures. Human dentin demineralization was performed with phosphoric acid (PA), EDTA, or acidic monomers (ClearfilSEBond and XENOV). Specimens were stored (24 h, 1 wk or 3 wk) in the presence or absence of chlorhexidine. In half of the groups, active MMP-2 was incorporated into the storing solution. C-terminal telopeptide determination (ICTP) was performed in the supernatants. Collagen degradation was higher in PA and EDTA-demineralized dentin. Chlorhexidine reduced collagen degradation in these groups only for 24 h. When dentin was demineralized with SEBond or Xeno, collagen degradation was reduced up to 30%, but addition of exogenous MMP-2 significantly increased collagen degradation. In self-etchant treated dentin the inhibitory effect of chlorhexidine on MMPs lasted up to 3 wk. Treating dentin with EDTA, PA or self-etching agents produces enough demineralization to permit cleavage of the exposed collagen. Monomers infiltration may exert protection on demineralized collagen, probably through immobilization of MMPs. The partial inhibitory action of CHX on MMP activity produced by self-etching adhesives was prolonged compared to the short-acting in PA or EDTA-treated dentin. PMID:21244516

Evaluating EDTA as a substitute for phosphoric acid-etching of enamel and dentin.

PubMed

Imbery, Terence A; Kennedy, Matthew; Janus, Charles; Moon, Peter C

2012-01-01

Matrix metalloproteinases (MMPs) are proteolytic enzymes released when dentin is acid-etched. The enzymes are capable of destroying unprotected collagen fibrils that are not encapsulated by the dentin adhesive. Chlorhexidine applied after etching inhibits the activation of released MMPs, whereas neutral ethylenediamine tetra-acetic acid (EDTA) prevents the release of MMPs. The purpose of this study was to determine if conditioning enamel and dentin with EDTA can be a substitute for treating acid-etching enamel and dentin with chlorhexidine. A column of composite resin was bonded to enamel and dentin after conditioning. Shear bond strengths were evaluated after 48 hours and after accelerated aging for three hours in 12% sodium hypochlorite. Shear bond strengths ranged from 15.6 MP a for accelerated aged EDTA enamel specimens to 26.8 MPa for dentin conditioned with EDTA and tested after 48 hours. A three-way ANOVA and a Tukey HSD test found statistically significant differences among the eight groups and the three independent variables (P < 0.05). EDTA was successfully substituted for phosphoric acid-etched enamel and dentin treated with chlorhexidine. Interactions of conditioning agent and aging were significant for dentin but not for enamel. In an effort to reduce the detrimental effects of MMPs, conditioning enamel and dentin with EDTA is an alternative to treating acid-etched dentin and enamel with chlorhexidine.

Exploratory randomised controlled clinical study to evaluate the comparative efficacy of two occluding toothpastes - a 5% calcium sodium phosphosilicate toothpaste and an 8% arginine/calcium carbonate toothpaste - for the longer-term relief of dentine hypersensitivity.

PubMed

Hall, Claire; Mason, Stephen; Cooke, Jonathan

2017-05-01

To compare the longer-term clinical efficacy of two occlusion-technology toothpastes - a 5% calcium sodium phosphosilicate (CSPS) toothpaste and a commercially available 8% arginine/calcium carbonate toothpaste - in relieving dentine hypersensitivity (DH). Efficacy was also compared with that of a regular fluoride toothpaste control. This was an exploratory, randomised, examiner-blind, parallel-group, 11-week, controlled study in healthy adults with self-reported and clinically diagnosed DH. After an acclimatisation period, subjects were randomised to one of three study treatments with which they brushed their teeth twice daily. Sensitivity was assessed at baseline and after 1, 2, 4, 6 and 11 weeks treatment in response to evaporative (air) and tactile stimuli (measured by the Schiff Sensitivity Scale/visual analogue scale and tactile threshold, respectively). A total of 135 subjects were randomised to treatment. The two occlusion-technology toothpastes performed similarly over the 11-week treatment period. All study treatments showed statistically significant reductions from baseline in DH at all timepoints for all measures (p<0.05). Statistically significant and clinically relevant sensitivity relief was observed for both occluding formulations compared with the regular fluoride toothpaste: for evaporative (air) sensitivity within 1 week and for tactile sensitivity at Week 11. No significant differences were detected between the two occluding formulations at any timepoint, for any endpoint. Study treatments were generally well tolerated. In this exploratory study, a 5% CSPS occluding toothpaste was effective in relieving DH compared with a regular fluoride toothpaste; an 8% arginine/calcium carbonate anti-sensitivity toothpaste provided similar benefits. Improvements in DH continued throughout the 11-week study. Dentine hypersensitivity (DH) is a common and painful condition. Twice-daily use of a 5% calcium sodium phosphosilicate toothpaste reduces DH within 1-2 weeks of initiating use. Ongoing, twice daily use of the sensitivity toothpastes evaluated in this study was associated with continued, clinically significant improvements in DH. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

The role of erosion, abrasion and attrition in tooth wear.

PubMed

Barbour, Michele E; Rees, Gareth D

2006-01-01

There is increasing clinical awareness of erosion of enamel and dentine by dietary acids and the consequent increased susceptibility to physical wear. Enamel erosion is characterized by acid-mediated surface softening that, if unchecked, will progress to irreversible loss of surface tissue, potentially exposing the underlying dentine. In comparison, dentine erosion is less well understood as the composition and microstructure are more heterogeneous. Factors which affect the erosive potential of a solution include pH, titratable acidity, common ion concentrations, and frequency and method of exposure. Abrasion and attrition are sources of physical wear and are commonly associated with tooth brushing and tooth-to-tooth contact, respectively. A combination of erosion and abrasion or attrition exacerbates wear; however, further research is required to understand the role of fluoride in protecting mineralized tissues from such processes. Abrasive wear may be seen in a wide range of patients, whereas attritive loss is usually seen in individuals with bruxism. Wear processes are implicated in the development of dentine hypersensitivity. Saliva confers the major protective function against wear due to its role in pellicle formation, buffering, acid clearance, and hard tissue remineralization. This review focuses on the physiochemical factors impacting tooth wear.

Liquid nitrogen-treated autogenous dentin as bone substitute: an experimental study in a rabbit model.

PubMed

Atiya, Basim K; Shanmuhasuntharam, Palasuntharam; Huat, Siar; Abdulrazzak, Shurooq; Oon, Ha

2014-01-01

Different forms of dentin, including untreated, undemineralized, demineralized, boiled, or mixed with other materials, have been evaluated for efficacy as bone substitutes. However, the effects of application of liquid nitrogen-treated dentin for bone grafting remain unknown. The objective of this study was to chronologically evaluate bone healing following grafting with liquid nitrogen-treated dentin in a rabbit model. Autogenous dentin treated with liquid nitrogen at -196°C for 20 minutes was used. In 16 New Zealand White rabbits, a bone defect (5 mm in diameter) was created in each femur and randomly grafted with either autogenous dentin (experimental group) or autogenous bone grafts (positive control). In another four rabbits (negative control), a similar defect in each femur was left empty. The rabbits were sacrificed at 2, 4, 8, and 12 weeks. Explants of grafted sites were harvested for histologic and histomorphometric analysis. At 2 and 4 weeks in both the experimental and positive control groups, accelerated formation of new bone was observed, which was undergoing remodeling at 8 and 12 weeks. The mean new bone score was higher in the experimental than in the negative control groups, but this was not statistically significant. The present results demonstrated that liquid nitrogen-treated autogenous dentin has both osteoconductive and osteoinductive properties and therefore has potential as a bone substitute.

The evaluation of dentinal tubule occlusion by desensitizing agents: a real-time measurement of dentinal fluid flow rate and scanning electron microscopy.

PubMed

Kim, S Y; Kim, E J; Kim, D S; Lee, I B

2013-01-01

The aims of this study were to examine changes in dentinal fluid flow (DFF) during the application of a desensitizing agent and to compare the permeability reduction levels among different types of desensitizing agents. A cervical cavity was prepared for the exposure of cervical dentin on an extracted human premolar connected to a subnanoliter fluid flow measuring device under 20 cm of water pressure. The cavity was acid-etched with 32% phosphoric acid to make dentin highly permeable. The different types of desensitizing agents that were applied on the cavity were Seal&Protect as the light-curing adhesive type, SuperSeal and BisBlock as oxalate types, Gluma Desensitizer as the protein-precipitation type, and Bi-Fluoride 12 as the fluoride type. DFF was measured from the time before the application of the desensitizing agent throughout the application procedure to five minutes after the application. The characteristics of dentinal tubule occlusion of each desensitizing agent were examined by scanning electron microscopy. The DFF rate after each desensitizing agent application was significantly reduced when compared to the initial DFF rate before application for all of the desensitizing agents (p<0.05). Seal&Protect showed a greater reduction in the DFF rate when compared to Gluma Desensitizer and Bi-Fluoride 12 (p<0.05). SuperSeal and BisBlock exhibited a greater reduction in DFF rate when compared to Bi-Fluoride 12 (p<0.05). The dentin hypersensitivity treatment effects of the employed desensitizing agents in this study were confirmed through real-time measurements of DFF changes. The light-curing adhesive and oxalate types showed greater reduction in the DFF rate than did the protein-precipitation and fluoride types.

Orofacial manifestations in outpatients with anorexia nervosa and bulimia nervosa focusing on the vomiting behavior.

PubMed

Lourenço, Maria; Azevedo, Álvaro; Brandão, Isabel; Gomes, Pedro S

2018-06-01

This case-control study aims to evaluate the oral health status and orofacial problems in a group of outpatients with eating disorders (ED)-either anorexia nervosa (AN) or bulimia nervosa (BN)-further focusing on the influence of vomit. Fifty-five women outpatients with AN or BN diagnosis were invited to participate, of which 33 agreed. ED outpatients and matched controls were submitted to a questionnaire and clinical oral examination. Multivariate analysis identified a significantly higher incidence of teeth-related complications (i.e., tooth decay, dental erosion, and self-reported dentin hypersensitivity), periodontal disease, salivary alterations (i.e., hyposalivation and xerostomia), and oral mucosa-related complications in ED outpatients. Dental erosion, self-reported dentin hypersensitivity, hyposalivation, xerostomia, and angular cheilitis were found to be highly correlated with the vomiting behavior. ED outpatients were found to present a higher incidence of oral-related complications and an inferior oral health status, compared to gender- and age-matched controls. Alterations verified within outpatients were acknowledged to be quite similar to those previously reported within inpatients, in both of nature and severity, thus sustaining that the cranio-maxillofacial region is significantly affected by ED, even in the early/milder forms of the condition, as expectedly verified within outpatients.

Carbodiimide Inactivation of MMPs and Effect on Dentin Bonding

PubMed Central

Mazzoni, A.; Apolonio, F.M.; Saboia, V.P.A.; Santi, S.; Angeloni, V.; Checchi, V.; Curci, R.; Di Lenarda, R.; Tay, F.R.; Pashley, D.H.; Breschi, L.

2014-01-01

The use of protein cross-linking agents during bonding procedures has been recently proposed to improve bond durability. This study aimed to use zymography and in situ zymography techniques to evaluate the ability of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) cross-linker to inhibit matrix metalloproteinase (MMP) activity. The hypotheses tested were that: (1) bonding procedures increase dentin gelatinolytic activity and (2) EDC pre-treatment prevents this enzymatic activity. The zymographic assay was performed on protein extracts obtained from dentin powder treated with Optibond FL or Scotchbond 1XT with or without 0.3M EDC pre-treatment. For in situ zymography, adhesive/dentin interfaces were created with the same adhesives applied to acid-etched dentin slabs pre-treated or not with EDC conditioner. Zymograms revealed increased expression of dentin endogenous MMP-2 and -9 after adhesive application, while the use of EDC as a primer inactivated dentin gelatinases. Results of in situ zymograpy showed that hybrid layers of tested adhesives exhibited intense collagenolytic activity, while almost no fluorescence signal was detected when specimens were pre-treated with EDC. The correlative analysis used in this study demonstrated that EDC could contribute to inactivate endogenous dentin MMPs within the hybrid layer created by etch-and-rinse adhesives. PMID:24334409

Shear bond strength of composite to deep dentin after treatment with two different collagen cross-linking agents at varying time intervals.

PubMed

Srinivasulu, S; Vidhya, S; Sujatha, M; Mahalaxmi, S

2012-01-01

This in vitro study evaluated the shear bond strength of composite resin to deep dentin using a total etch adhesive after treatment with two collagen cross-linking agents at varying time intervals. Thirty freshly extracted human maxillary central incisors were sectioned longitudinally into equal mesial and distal halves (n=60). The proximal deep dentin was exposed, maintaining a remaining dentin thickness (RDT) of approximately 1 mm. The specimens were randomly divided into three groups based on the surface treatment of dentin prior to bonding as follows: group I (n=12, control): no prior dentin surface treatment; group II (n=24): dentin surface pretreated with 10% sodium ascorbate; and group III (n=24): dentin surface pretreated with 6.5% proanthocyanidin. Groups II and III were further subdivided into two subgroups of 12 specimens each, based on the pretreatment time of five minutes (subgroup A) and 10 minutes (subgroup B). Shear bond strength of the specimens was tested with a universal testing machine, and the data were statistically analyzed. Significantly higher shear bond strength to deep dentin was observed in teeth treated with 10% sodium ascorbate (group II) and 6.5% proanthocyanidin (group III) compared to the control group (group I). Among the collagen cross-linkers used, specimens treated with proanthocyanidin showed significantly higher shear bond strength values than those treated with sodium ascorbate. No significant difference was observed between the five-minute and 10-minute pretreatment times in groups II and III. It can be concluded that dentin surface pretreatment with both 10% sodium ascorbate and 6.5% proanthocyanidin resulted in significant improvement in bond strength of resin composite to deep dentin.

Nanoleakage of dentin adhesive systems bonded to Carisolv-treated dentin.

PubMed

Kubo, Shisei; Li, Heping; Burrow, Michael F; Tyas, Martin J

2002-01-01

The hybrid layer created in caries-affected dentin has not been fully elucidated and may influence bond durability. This study investigated the nanoleakage patterns of caries-affected dentin after excavation with Carisolv or conventional instruments treated with one of three adhesive systems. Flat occlusal dentin surfaces, including carious lesions, were prepared from extracted human molars and finished with wet 600-grit silicon carbide paper. Carious dentin was removed with Carisolv or round steel burs in conjunction with Caries Detector. PermaQuik, Single Bond or One-Up Bond F was bonded to the excavated dentin surfaces and adjacent flat occlusal surfaces and it was covered with Silux Plus resin-based composite. After 24-hour storage in 37 degrees C water, the bonded interfaces were polished to remove flash, and the surrounding tooth surfaces were coated with nail varnish. Specimens were immersed in 50% (w/v) silver nitrate solution for 24 hours, exposed to photo developing solution for eight hours, then sectioned longitudinally through the bonded, excavated dentin or "normal" dentin surfaces. The sectioned surfaces were polished, carbon coated and observed in a Field Emission-SEM using back scattered electrons. Silver deposition occurred along the base of the hybrid layer for all specimens. However, Single Bond showed a greater density of silver deposition in the caries-affected dentin compared with normal dentin. PermaQuik had a thicker hybrid layer in caries-affected dentin than normal dentin. One-Up Bond F exhibited a thin hybrid layer in normal dentin, but the hybrid layer was often difficult to detect in caries-affected dentin.

Assessment of the amount of remaining coronal dentine in root-treated teeth.

PubMed

Bandlish, R B; McDonald, A V; Setchell, D J

2006-10-01

There is currently no standardised technique to measure the amount of coronal dentine remaining in a root-treated tooth after crown preparation. The aim of this study was to develop a method of measuring remaining coronal dentine in root-treated teeth and to propose an index for grading tooth restorability. The study recruited 20 patients who had completed molar endodontic treatment at the Eastman Dental Hospital and had been prescribed an amalgam coronal-radicular core with a full coverage cast restoration. Using a series of interlocking special trays and impressions, a method was devised to produce a cast of the amount of remaining dentine coronal to the finish line after crown preparation. This cast was scanned using a laser profilometer and the volume of remaining dentine was calculated. A tooth restorability index (TRI) was developed to assess the strategic value of the remaining dentine. The TRI allowed scores of 0-3 in each sextant with a maximum score of 18 per tooth. Twenty teeth were scored by three examiners and the TRI scores varied from 2 to 13. The volume of coronal dentine varied from 61.73 to 232.22 mm(3). A tooth restorability index has been devised to assess the strategic value of remaining dentine. A Kappa statistic was calculated to produce values of 0.584, 0.688 and 0.720, giving moderate-good agreement between the examiners.

In vitro dentin permeability after application of Gluma® desensitizer as aqueous solution or aqueous fumed silica dispersion

PubMed Central

ISHIHATA, Hiroshi; FINGER, Werner J.; KANEHIRA, Masafumi; SHIMAUCHI, Hidetoshi; KOMATSU, Masashi

2011-01-01

Objectives To assess and to compare the effects of Gluma® Desensitizer (GDL) with an experimental glutaraldehyde and HEMA containing fumed silica dispersion (GDG) on dentin permeability using a chemiluminous tracer penetration test. Material and Methods Twenty disc-shaped dentin specimens were dissected from extracted human third molars. The dentin specimens were mounted in a split chamber device for determination of permeability under liquid pressure using a photochemical method. Ten specimens were randomly selected and allocated to the evaluation groups Gluma® Desensitizer as aqueous solution and glutaraldehyde/HEMA as fumed silica dispersion, respectively. Dentin disc permeability was determined at two pressure levels after removal of smear with EDTA, after albumin soaking, and after application of the desensitizing agents. Two desensitizer-treated and rinsed specimens of each group were examined by scanning electron microscopy (SEM) for surface remnants. Results Comparatively large standard deviations of the mean EDTA reference and albumin soaked samples permeability values reflected the differences of the dentin substrates. The mean chemiluminescence values of specimen treated with GDL and GDG, respectively, were significantly reduced after topical application of the desensitizing agents on albumin-soaked dentin. The effects of GDL and GDG on permeability were not significantly different. Treated specimens showed no surface remnants after rinsing. Conclusions The experimental desensitizer gel formulation reduced dentin permeability as effectively as the original Gluma® Desensitizer solution. PMID:21552716

The effect of 25% tannic acid on prepared dentin: a scanning electron microscope-methylene blue dye study.

PubMed

Bitter, N C

1990-07-01

The effect on the permeability of prepared dentin treated with 25% tannic acid and 6% citric acid was compared with the untreated dentinal surface. Methylene blue was applied to the dentin surface after treatment to evaluate penetration into dentinal tubules. The tannic acid solution reduced or prevented dye penetration of the dentinal tubules. Citric acid treatment permitted severe penetration. The 25% tannic acid solution removed the smear layer while inhibiting penetration of the dye.

Effect of dimethyl sulfoxide on dentin collagen.

PubMed

Mehtälä, P; Pashley, D H; Tjäderhane, L

2017-08-01

Infiltration of adhesive on dentin matrix depends on interaction of surface and adhesive. Interaction depends on dentin wettability, which can be enhanced either by increasing dentin surface energy or lowering the surface energy of adhesive. The objective was to examine the effect of dimethyl sulfoxide (DMSO) on demineralized dentin wettability and dentin organic matrix expansion. Acid-etched human dentin was used for sessile drop contact angle measurement to test surface wetting on 1-5% DMSO-treated demineralized dentin surface, and linear variable differential transformer (LVDT) to measure expansion/shrinkage of dentinal matrix. DMSO-water binary liquids were examined for surface tension changes through concentrations from 0 to 100% DMSO. Kruskal-Wallis and Mann-Whitney tests were used to test the differences in dentin wettability, expansion and shrinkage, and Spearman test to test the correlation between DMSO concentration and water surface tension. The level of significance was p<0.05. Pretreatment with 1-5% DMSO caused statistically significant concentration-dependent increase in wetting: the immediate contact angles decreased by 11.8% and 46.6% and 60s contact angles by 9.5% and 47.4% with 1% and 5% DMSO, respectively. DMSO-water mixtures concentration-dependently expanded demineralized dentin samples less than pure water, except with high (≥80%) DMSO concentrations which expanded demineralized dentin more than water. Drying times of LVDT samples increased significantly with the use of DMSO. Increased dentin wettability may explain the previously demonstrated increase in adhesive penetration with DMSO-treated dentin, and together with the expansion of collagen matrix after drying may also explain previously observed increase in dentin adhesive bonding. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

[The application of laser in endodontics].

PubMed

He, W X; Liu, N N; Wang, X L; He, X Y

2016-08-01

Since laser was introduced in the field of medicine in 1970's, its application range has continuously expanded. The application of laser in endodontics also increased due to its safety and effectiveness in dental treatments. The majority of the laser application researches in dentistry focused on dentin hypersensitivity, removal of carious tissues, tooth preparations, pulp capping or pulpotomy, and root canal treatment. In this article, we reviewed literature on the effects of laser in the treatments of dental and pulp diseases.

Immediate efficacy of diode laser application in the treatment of dentine hypersensitivity in periodontal maintenance patients: a randomized clinical trial.

PubMed

Sicilia, Alberto; Cuesta-Frechoso, Susana; Suárez, Alfonso; Angulo, Jorge; Pordomingo, Armando; De Juan, Pablo

2009-08-01

To evaluate the immediate efficacy in the reduction of dentine hypersensitivity (DH) when applying an 810 nm diode laser (DL), and a 10% potassium nitrate bioadhesive gel (NK10%). Forty-five consecutive periodontal maintenance patients of both sexes, with a DH >or= 2 on the verbal rating scale (VRS) in one or more teeth, were randomly allocated into three equal groups: 15 patients received DL and placebo gel; 15 patients were tested with a placebo laser and NK10%; and the remaining 15 received a placebo laser and placebo gel. The DH was evaluated at the start of the study, 15 and 30 min. after the laser application, and on days 2, 4, 7, 14, 30 and 60 by a blind examiner. After 15 min., observations showed a reduction in DH after an evaporative stimulus (ES) of 36.9% (0.86), three times greater than that of the control group (0.23) (p=0.008). After 14 days, this effect was even greater [DL 71.7% (1.67)/NK10% 36.3% (1.73)/control 28.1% (0.73); p=0.004], and lasted until day 60 [65.7% (1.53)/30.4% (0.73)/25.8% (0.67); p=0.01]. The DL and NK10% gel were proven effective in the treatment of DH. A significantly greater immediate response was observed with DL.

Experimental resin cements containing bioactive fillers reduce matrix metalloproteinase-mediated dentin collagen degradation.

PubMed

Osorio, Raquel; Yamauti, Monica; Sauro, Salvatore; Watson, Thimoty F; Toledano, Manuel

2012-09-01

Collagen dentin matrix may represent a suitable scaffold to be remineralized in the presence of bioactive materials. The purpose of this study was to determine if experimental resin cements containing bioactive fillers may modulate matrix metalloproteinase-mediated collagen degradation of etched dentin. Human dentin beams demineralized using 10% phosphoric acid or 0.5 mol/L EDTA were infiltrated with the following experimental resins: (1) unfilled resin, (2) resin with Bioglass 45S5 particles (Sylc; OSspray Ltd, London, UK), and (3) resin with β-tricalcium phosphate-modified calcium silicate cement (HCAT-β) particles. The filler/resin ratio was 40/60 wt%. The specimens were stored in artificial saliva, and the determination of C-terminal telopeptide (ICTP) was performed by radioimmunoassay after 24 hours, 1 week, and 4 weeks. Scanning electron microscopic analysis of dentin surfaces after 4 weeks of storage was also executed. Collagen degradation was prominent both in phosphoric acid and EDTA-treated dentin. Resin infiltration strongly reduced the MMP activity in demineralized dentin. Resin-containing Bioglass 45S5 particles exerted higher and more stable protection of collagen at all tested dentin states and time points. HCAT-β induced collagen protection from MMPs only in EDTA-treated specimens. Dentin remineralization was achieved when dentin was infiltrated with the resin cements containing bioactive fillers. MMP degradation of dentin collagen is strongly reduced in resin-infiltrated dentin. The inclusion of Bioglass 45S5 particles exerted an additional protection of collagen during dentin remineralization. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Effects of air polishing and an amino acid buffered hypochlorite solution to dentin surfaces and periodontal ligament cell survival, attachment, and spreading.

PubMed

Schmidlin, Patrick R; Fujioka-Kobayashi, Masako; Mueller, Heinz-Dieter; Sculean, Anton; Lussi, Adrian; Miron, Richard J

2017-06-01

The aim of this study is to examine morphological changes of dentin surfaces following air polishing or amino acid buffered hypochlorite solution application and to assess their influence on periodontal ligament (PDL) cell survival, attachment, and spreading to dentin discs in vitro. Bovine dentin discs were treated with either (i) Classic, (ii) Plus, or (iii) Perio powder (EMS). Furthermore, Perisolv® a hypochlorite solution buffered with various amino acids was investigated. Untreated dentin discs served as controls. Morphological changes to dentin discs were assessed using scanning electron microscopy (SEM). Human PDL cells were seeded onto the respectively treated discs, and samples were then investigated for PDL cell survival, attachment, and spreading using a live/dead assay, adhesion assay, and SEM imaging, respectively. Both control and Perisolv®-rinsed dentin discs demonstrated smooth surfaces at low and high magnifications. The Classic powders demonstrated the thickest coating followed by the Powder Plus. The Perio powder demonstrated marked alterations of dentin discs by revealing the potential to open dentinal tubules even before rinsing. Seeding of PDL cells demonstrated an almost 100 % survival rate on all samples demonstrating very high biocompatibility for all materials. Significantly higher PDL cell numbers were observed on samples treated with the Perio powder and the Perisolv® solution (approximately 40 % more cells; p < 0.05). SEM imaging revealed the potential for PDL cells to attach and spread on all surfaces. The results from the present study demonstrate that cell survival and spreading of PDL cells on root surfaces is possible following either air polishing or application with Perisolv®. Future in vitro and animal testing is necessary to further characterize the beneficial effects of either system in a clinical setting. The use of air polishing or application with Perisolv amino acid buffered hypochlorite solution was effective in treating root surfaces and allowed for near 100 % PDL cell survival, attachment, and spreading onto all root surfaces.

Effect of conditioning solutions containing ferric chloride on dentin bond strength and collagen degradation.

PubMed

Rodrigues, Raquel Viana; Giannini, Marcelo; Pascon, Fernanda Miori; Panwar, Preety; Brömme, Dieter; Manso, Adriana Pigozzo; Carvalho, Ricardo Marins

2017-10-01

To investigate the effects of conditioning solutions containing ferric chloride (FeCl 3 ) on resin-dentin bond strength; on protection of dentin collagen against enzymatic degradation and on cathepsin-K (CT-K) activity. Conditioning solutions were prepared combining citric acid (CA) and anhydrous ferric chloride (FeCl 3 ) in different concentrations. The solutions were applied to etch flat dentin surfaces followed by bonding with adhesive resin. Phosphoric acid (PA) gel etchant was used as control. The microtensile bond strength (μTBS) was tested after 24h of storage in water and after 9 months of storage in phosphate buffer saline. Dentin slabs were demineralized in 0.5M EDTA, pre-treated or not with FeCl 3 and incubated with CT-K. The collagenase activity on dentin collagen matrix was examined and characterized by SEM. Additional demineralized dentin slabs were treated with the conditioning solutions, and the amount of Fe bound to collagen was determined by EDX. The activity of CT-K in the presence of FeCl 3 was monitored fluorimetrically. Data were analyzed by ANOVA followed by post-hoc tests as required (α=5%). Slightly higher bond strengths were obtained when dentin was conditioned with 5% CA/0.6% FeCl 3 and 5% CA-1.8%FeCl 3 regardless of storage time. Bond strengths reduced significantly for all tested conditioners after 9 months of storage. Treating dentin with 1.8% FeCl 3 was effective to preserve the structure of collagen against CT-K. EDX analysis revealed binding of Fe-ions to dentin collagen after 15s immersion of demineralized dentin slabs into FeCl 3 solutions. FeCl 3 at concentration of 0.08% was able to suppress CT-K activity. This study shows that FeCl 3 binds to collagen and offers protection against Cat-K degradation. Mixed solutions of CA and FeCl 3 may be used as alternative to PA to etch dentin in resin-dentin bonding with the benefits of preventing collagen degradation. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Influences of the cold atmospheric plasma jet treatment on the properties of the demineralized dentin surfaces

NASA Astrophysics Data System (ADS)

Xiaoming, ZHU; Heng, GUO; Jianfeng, ZHOU; Xiaofei, ZHANG; Jian, CHEN; Jing, LI; Heping, LI; Jianguo, TAN

2018-04-01

Improvement of the bonding strength and durability between the dentin surface and the composite resin is a challenging job in dentistry. In this paper, a radio-frequency atmospheric-pressure glow discharge (RF-APGD) plasma jet is employed for the treatment of the acid-etched dentin surfaces used for the composite restoration. The properties of the plasma treated dentin surfaces and the resin-dentin interfaces are analyzed using the x-ray photoemission spectroscopy, contact angle goniometer, scanning electron microscope and microtensile tester. The experimental results show that, due to the abundant chemically reactive species existing in the RF-APGD plasma jet under a stable and low energy input operating mode, the contact angle of the plasma-treated dentin surfaces decreases to a stable level with the increase of the atomic percentage of oxygen in the specimens; the formation of the long resin tags in the scattered clusters and the hybrid layers at the resin-dentin interfaces significantly improve the bonding strength and durability. These results indicate that the RF-APGD plasma jet is an effective tool for modifying the chemical properties of the dentin surfaces, and for improving the immediate bonding strength and the durability of the resin-dentin bonding in dentistry.

Biomimetic mineralization: long-term observations in patients with dentin sensitivity.

PubMed

Guentsch, Arndt; Seidler, Karin; Nietzsche, Sandor; Hefti, Arthur F; Preshaw, Philip M; Watts, David C; Jandt, Klaus D; Sigusch, Bernd W

2012-04-01

Cervical tooth erosion is increasingly observed among adults and frequently associated with dentin sensitivity (DS). This study evaluated the effectiveness on DS of a biomimetic mineralization system (BIMIN) in comparison to the current standard treatment (Gluma(®) Desensitizer, Gluma). In this single-blind, 2-arm study, 40 patients with confirmed cervical DS were randomized to either the test group or the positive control group. A Visual-Analog-Scale (VAS) was used to assess DS following stimulation of the exposed dentin with a 2-s air blast. Assessments were made at baseline (pre-treatment), 2 days, 4, 8 and 12 weeks, and 12 months after treatment. Two-stage replicas were obtained from the treated teeth and gold sputtered at baseline, and 2 days, 3 and 12 months after treatment. Surface topography of the treated cervical lesions and occlusion of dentinal tubules were investigated using scanning electron microscopy (SEM). Both treatments led to a statistically significant reduction (P<0.0001) in DS that persisted over the entire 12-month observation period. Differences in DS between the treatments were not statistically significant. SEM photomicrographs demonstrated that a mineral layer concealed the dentinal tubules in the test group. In contrast, numerous dentinal tubules remained visible in cervical defects that were treated with Gluma. A biomimetic mineralization kit was successfully used to treat patients exhibiting DS. The effect was similar to using Gluma, and was likely the result of the deposition of an enamel-like layer on the exposed cervical dentin. Copyright © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Treatment of dentinal tubules by Nd:YAG laser

NASA Astrophysics Data System (ADS)

Chmelíčkova, Hana; Zapletalova, Zdeňka; Peřina, Jan, Jr.; Novotný, Radko; Kubínek, Roman; Stranyánek, Martin

2005-08-01

Symptom of cervical dentine hypersensitivity attacks from 10% to 15% of population and causes an uncomfortable pain during contact with any matter. Sealing of open dentinal tubules is one of the methods to reach insensibility. Laser as a source of coherent radiation is used to melt dentine surface layers. Melted dentine turns to hard mass with a smooth, non-porous surface. Simulation of this therapy was made in vitro by means of LASAG Nd:YAG pulsed laser system KLS 246-102. Eighty human extracted teeth were cut horizontally to obtain samples from 2 mm to 3 mm thick. First experiments were done on cross section surfaces to find an optimal range of laser parameters. A wide range of energies from 30 mJ to 210 mJ embedded in 0,3 ms long pulse was tested. Motion in X and Y axes was ensured by a CNC driven table and the pulse frequency 15 Hz was chosen to have a suitable overlap of laser spots. Some color agents were examined with the aim to improve surface absorption. Scanning Electron Microscopy was used to evaluate all samples and provided optimal values of energies around 50 J.cm-2. Next experiments were done with the beam oriented perpendicularly to a root surface, close to the real situation. Optical fibers with the diameter of 0,6 mm and 0,2 mm were used to guide a laser beam to teeth surfaces. Laser processing heads with lens F = 100 mm and F = 50 mm were used. The best samples were investigated by means of the Atomic Force Microscopy.

Ultrastructural properties of laser-irradiated and heat-treated dentin.

PubMed

Rohanizadeh, R; LeGeros, R Z; Fan, D; Jean, A; Daculsi, G

1999-12-01

Previous studies using scanning electron microscopy and infrared absorption spectroscopy reported that laser irradiation causes compositional changes in enamel. The purpose of this study was to evaluate the ultrastructural and compositional changes in dentin caused by irradiation with a short-pulse laser (Q-switched Nd:YAG). The irradiated and non-irradiated areas of the lased dentin samples were investigated by scanning (SEM) and transmission electron microscopy (TEM), micro-micro electron diffraction, and electron microprobe analysis of dispersive energy (EDX). Heat-treated dentin was similarly investigated. This study demonstrated that laser irradiation resulted in the recrystallization of dentin apatite and in the formation of additional calcium phosphate phases consisting of magnesium-substituted beta-tricalcium phosphate, beta-TCMP, beta-(Ca,Mg)3(PO4)2, and tetracalcium phosphate, TetCP, Ca4(PO4)O. TEM analyses of the modified and unmodified zones of the irradiated areas showed two types of crystal populations: much larger crystals from the modified zone and crystals with size and morphology similar to those of dentin apatite in the unmodified zone. The morphology of crystals in the modified zones in the irradiated dentin resembled those of dentin sintered at 800 or 950 degrees C. In the irradiated areas (modified and unmodified zones), the Ca/P ratio was lower compared with that in the non-irradiated dentin. The Mg/Ca ratio in the modified zones was higher than that in the unmodified zones and in the non-irradiated dentin. In sintered dentin, the Mg/Ca ratio increased as a function of sintering temperature. The ultrastructural and compositional changes observed in laser-irradiated dentin may be attributed to high temperature and high pressure induced by microplasma during laser irradiation. These changes may alter the solubility of the irradiated dentin, making it less susceptible to acid dissolution or to the caries process.

Oral health sentinel-based surveillance: a pilot study on dentinal hypersensitivity pain.

PubMed

Guerra, F; Corridore, D; Cocco, F; Arrica, M; Rinaldo, F; Mazur, M; Sanavia, C; Nardi, G M; Campus, G; Ottolenghi, L

2017-01-01

Aim of the study is to assess the development of a structured sentinel system for oral health data collection at national level. Furthermore, this pilot study aims to investigate the prevalence data on dentinal sensitivity pain collected through a nationwide network of epidemiological sentinels (dental hygienists). Each sentinel was given a specific number of examinees and periodicity of data collection. Overall, 116 adults were recruited from 19 Regions, 42,24% male and 57,76% female, with a mean age of 26. DH result was consistent with literature data, being 45%. All sentinel completed the standard forms and assured a good compliance. The overall good customer satisfaction assures adhesion of the sentinels to the procedure, and the regular data collection. The pilot study proved the effectiveness of a structured nationwide network of epidemiological sentinels (dental hygienists) for oral health data collection at national level. This methodology can be an essential starting point for periodic comparative studies.

Evaluation of the colour change in enamel and dentine promoted by the interaction between 2% chlorhexidine and auxiliary chemical solutions.

PubMed

Souza, Matheus; Cecchin, Doglas; Barbizam, Joao V B; Almeida, José F A; Zaia, Alexandre Augusto; Gomes, Brenda P F A; Ferraz, Caio C R

2013-12-01

To evaluate the colour change in enamel and dentine, promoted by interaction of 2% chlorhexidine gluconate (CHX) with 5.25% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacetic acid (EDTA). Fragments containing enamel and dentine were obtained from the crowns of extracted bovine incisors. Before and after immersion of the samples in the substances, they were evaluated with reference to the colour of the enamel and dentine. The values obtained in numerical scores were subjected to statistical analysis using Wilcoxon test. A colour change in the enamel and dentine in groups treated with CHX gel + NaOCl and CHX gel + NaOCl + EDTA, and a change in colour only in the dentine in groups treated with CHX solution + NaOCl and CHX solution + NaOCl + EDTA. When used prior to NaOCl, CHX has the ability to induce a colour change in dental structures. © 2011 The Authors. Australian Endodontic Journal © 2011 Australian Society of Endodontology.

A safety study in vitro for the effects of an in-office bleaching system on the integrity of enamel and dentine.

PubMed

Sulieman, M; Addy, M; Macdonald, E; Rees, J S

2004-09-01

The aim of this study was to investigate safety concerns with bleaching procedures by studying the effects of a high concentration hydrogen peroxide (HP) in-surgery bleaching product on enamel and dentine. Flat enamel and dentine samples embedded in epoxy resin were prepared from human third molar teeth. Erosion of enamel: groups of enamel samples were treated with 35% HP then citric acid (CA) or brushing with toothpaste or CA alone and water alone. Enamel Loss was measured using a profilometer. Abrasion/erosion of dentine: groups of dentine specimens were treated as follows: Group 1--brushed with water for 30 min. Group 2--brushed with 35% HP for 30 min. Group 3--power bleached for 30 min and then Group 4--brushed with toothpaste for 1 minute. Group 5--water soaked for 30 min followed by brushing with toothpaste for 1 min. Group 6--orange juice soaked for 30 min followed by brushing with toothpaste for 1 min. Treatment effects were measured using a profilometer. Hardness tests: enamel and dentine specimens were hardness tested using a Wallace indenter prior to and post bleaching. Scanning Electron Microscopy: enamel and dentine specimens were taped and the exposed tissue treated with 35% HP and then studied under scanning electronmicroscopy (SEM). Enamel erosion: bleaching enamel samples had no measurable effect on enamel. Pre-bleaching had no significant effect on subsequent CA erosion or brushing. Abrasion/erosion of dentine: no significant differences were found between treatments 1-5 with little change from baseline detected. Orange juice (Group 6) produced considerable and significantly more erosion than other treatments. Hardness tests: there were no significant changes in hardness values for enamel and dentine. SEM: there was no evidence of any topographical changes to either enamel or dentine. Using one of the highest concentrations of HP for tooth bleaching procedures and maximum likely peroxide exposure, there was no evidence of deleterious effects on enamel or dentine. It must be assumed that studies which reported adverse effects on enamel and or dentine of bleaches reflect not the bleach itself but the pH of the formulation used.

Evaluation of Nd:YAG laser on partial oxygen saturation of pulpal blood in anterior hypersensitive teeth.

PubMed

Birang, Reza; Kaviani, Naser; Mohammadpour, Mehdi; Abed, Ahmad Moghareh; Gutknecht, Norbert; Mir, Maziar

2008-07-01

Dentine hypersensitivity has of long been known to be a common clinical problem in dental practices. Lasers have recently come to play a prominent role in the treatment of this disorder. They might, however, cause dental pulp damage. This study was conducted to evaluate the effect of Nd:yttrium-aluminum-garnet (YAG) laser on partial oxygen saturation of pulpal blood in sensitive anterior teeth. In this clinical trial, 65 hypersensitive teeth were selected and randomly allocated to two groups. The study group involved Nd:YAG laser treatment, while no treatment was employed for the control group. Using a pulse oximetry system, evaluations were preformed of the partial oxygen saturation in the pulpal blood before, immediately after, 1 week after, and 1 month after the treatment. The results were analyzed using the SPSS software and repeated-measures analysis of variance and paired-samples t tests. The mean partial oxygen saturation of the blood was found to be 85.4% in the study group, which was not significantly different from that of the control group. No significant differences were observed in the control group between the means obtained from pretreatment and post-treatment intervals (P > 0.05). The Post-treatment partial oxygen saturation mean rose to 89.3% (P = 0.001) and remained constant throughout the following week after it. However, no significant differences were found between the pretreatment partial oxygen saturation mean and the same measurement 1 month after treatment (P = 0.702). Nd:YAG laser therapy for dentine desensitization of anterior teeth caused no persistent changes in the partial oxygen saturation of pulpal blood. It may, therefore, be concluded that the diffusion of heat induced by the Nd:YAG laser into the pulp within the limit of the desensitization parameters cause no irreversible damages in the dental pulp.

In Vitro Evaluation of Dentin Tubule Occlusion for Novel Calcium Lactate Phosphate (CLP) Paste

PubMed Central

Yang, Jen-Chang; Hu, Hsin-Tai; Lee, Sheng-Yang; Hsieh, Sung-Chih; Huang, Pei-Chi; Ma, Chen-Feng; Ji, Dian-Yu; Chang, Liang-Yu; Teng, Nai-Chia

2017-01-01

Introduction: The objective of this in vitro study is to evaluate the effective and long-term occlusion of dentinal tubules using a novel calcium lactate phosphate (CLP) based desensitizing agent. Methods: Dentin disks (n = 9) were pre-etched using 1 M lactic acid for 30 s and individually treated with Colgate® Pro-Relief™ paste, CLP paste, and double distilled water (ddH2O) by a rubber-cupped handpiece. Dentin disks were analyzed under optical micrographs for pre-treatment, directly after treatment, and 14 days post-treatment. One-way ANOVA and post-hoc Tukey’s test were used to determine whether there were any statistically significant differences in dentinal tubule diameter. Results: A significant decrease occurred in the mean tubule diameter for dentin disks treated with CLP paste. A decrease was observed from 3.52 ± 0.83 µm to 2.62 ± 0.42 µm right after treatment, further decreasing to 1.71 ± 0.45 µm after immersion in artificial saliva for 14 days (p < 0.05). Conclusions: The results suggest that the CLP based desensitizing paste has remineralization properties and provides instant and lasting effectiveness in dentinal tubule occlusion. PMID:28772594

Comparative Evaluation of Effect of Nano-hydroxyapatite and 8% Arginine Containing Toothpastes in Managing Dentin Hypersensitivity: Double Blind Randomized Clinical Trial.

PubMed

Anand, Suresh; Rejula, Fathima; Sam, Joseph V G; Christaline, Ramakrishnan; Nair, Mali G; Dinakaran, Shiji

This double blind randomized clinical trial was conducted with the purpose of evaluating the effects of Nano-hydroxyapatite toothpaste as compared to 8% Arginine containing toothpaste in the management of Dentin hypersensitivity (DH). Patients (30 in each group) suffering from DH and eliciting a VAS score higher than 2 in air blast and tactile test were randomly allocated (block randomization) into either a group 1 (arginine toothpaste) or group 2 (nHA toothpaste). The primary outcome evaluated was the reduction of DH as measured by the electrical stimulus reading on the digital pulp tester. Current required for eliciting a VAS score of 2 was recorded before application of dentifrice. 1 cm of toothpaste was then expressed on the tooth surface for two minutes in each group and rinsed off. The electrical stimulus required to elicit a VAS score of 2 was recorded after 5 minutes, 1 week and 4 weeks. The desensitizing paste containing arginine provided a statistically significant reduction in DH and so did the paste containing nHA. Mean increase in amperage value (reduction in DH) was higher for nHA based than the arginine containing dentifrice. This difference was not statistically significant showing that both toothpastes are equally effective. The findings of the present study encourage the use of Nano-hydroxyapatite and arginine containing dentifrice as an effective desensitizing agent providing relief from symptoms 5 minutes after application and after 1 and 4 weeks.

Investigation of the prevalence, clinical features, and risk factors of dentin hypersensitivity in a selected Brazilian population.

PubMed

Scaramucci, Taís; de Almeida Anfe, Taciana Emília; da Silva Ferreira, Stella; Frias, Antônio Carlos; Sobral, Maria Angela Pita

2014-01-01

To evaluate the prevalence, clinical features, and risk factors of dentin hypersensitivity (DH) in a Brazilian population. 300 patients at the Dentistry Clinic of the University of São Paulo participated in this study. The subjects completed a questionnaire regarding their personal information, the presence of DH, and some of its risk factors. Following completion of the questionnaire, a clinical examination was undertaken. To confirm the presence of DH, the subjects were evaluated with the use of a probe and cold air from a triple syringe. Statistical analysis was performed with the chi-square test and odds ratio, with the critical level p <0.05. The prevalence of DH was 46%. Females presented a higher prevalence than males (p <0.05). The left posterior region was affected by DH the most (maxilla = 41% and mandible = 36%). Cold was reported as the most common pain-inducing stimulus (88%). The pain was described as "discomfort" by 51% of the subjects with DH. Toothbrushing four times a day (p <0.05), toothbrushing with excessive force (p <0.05), bruxism (p <0.05), and gastroesophageal reflux (p <0.05) were strongly correlated with DH. The prevalence of DH was particularly high. The risk factors for DH were gender (female), toothbrushing four times a day, toothbrushing with excessive force, bruxism, and gastroesophageal reflux. DH was a common finding in this population suggesting that preventive measures considering its risk factors must be implemented in order to reduce or control the symptoms.

Effect of desensitizing toothpastes on dentine hypersensitivity: A systematic review and meta-analysis.

PubMed

Hu, Meng-Long; Zheng, Gang; Zhang, You-Dong; Yan, Xiang; Li, Xiao-Chan; Lin, Hong

2018-05-19

To evaluate the desensitizing effect of toothpastes that contain ingredients that act against dentine hypersensitivity (DH) and to compare this effect with negative controls. Five databases were searched to identify relevant articles published up to November 27, 2017. Randomized controlled trials (RCTs) comparing desensitizing toothpastes with a toothpastes without desensitizing component in adult patients that suffer from DH were included. The risk of bias was assessed according to the Cochrane guidelines, and the quality of the evidence was evaluated using the GRADE tool. Inverse variance random-effects meta-analyses of standardized mean differences (SMD) and 95% confidence intervals (CIs) were calculated using RevMan 5.3 software. 53 RCTs with 4796 patients were finally included in the meta-analysis. The toothpastes that contain active desensitization ingredients showed a better desensitizing effect on DH than the negative control, except the strontium- and amorphous calcium phosphate-containing toothpastes. The amorphous calcium phosphate-containing toothpaste had very low-quality evidence, the strontium, potassium and strontium, and potassium and stannous fluoride-containing toothpastes had low-quality evidence, and the other five toothpastes had moderate quality evidence. Our result support the premise that toothpastes containing potassium, stannous fluoride, potassium and strontium, potassium and stannous fluoride, calcium sodium phosphosilicate, arginine, and nano-hydroxyapatite relieve the symptoms of DH, but does not advise the use of toothpastes that contain strontium and amorphous calcium phosphate. Furthermore, high-quality studies are needed to confirm our results. (PROSPERO CRD42018085639). Copyright © 2018 Elsevier Ltd. All rights reserved.

Estimation of Ultimate Tensile Strength of dentin Using Finite Element Analysis from Endodontically Treated Tooth

NASA Astrophysics Data System (ADS)

Sinthaworn, S.; Puengpaiboon, U.; Warasetrattana, N.; Wanapaisarn, S.

2018-01-01

Endodontically treated teeth were simulated by finite element analysis in order to estimate ultimate tensile strength of dentin. Structures of the endodontically treated tooth cases are flared root canal, restored with different number of fiber posts {i.e. resin composite core without fiber post (group 1), fiber post No.3 with resin composite core (group 2) and fiber post No.3 accessory 2 fiber posts No.0 with resin composite core (group 3)}. Elastic modulus and Poisson’s ratio of materials were selected from literatures. The models were loaded by the average fracture resistances load of each groups (group 1: 361.80 N, group 2: 559.46 N, group 3: 468.48 N) at 135 degree angulation in respect to the longitudinal axis of the teeth. The stress analysis and experimental confirm that fracture zone is at dentin area. To estimate ultimate tensile strength of dentin, trial and error of ultimate tensile strength were tested to obtain factor of safety (FOS) equal to 1.00. The result reveals that ultimate tensile strength of dentin of group 1, 2, 3 are 38.89, 30.96, 37.19 MPa, respectively.

Evaluation of a 6% hydrogen peroxide tooth whitening gel on enamel and dentine microhardness in vitro.

PubMed

Joiner, Andrew; Thakker, Gopal; Cooper, Yvonne

2004-01-01

The aims of this study were to evaluate the effects of a novel 6% hydrogen peroxide containing tooth whitener, Xtra White (XW), on enamel and dentine microhardness in vitro. Polished human enamel and dentine specimens were prepared and baseline microhardness determined. In study 1, enamel specimens were exposed to 20 min cycles of either water, XW or Sprite Light for up to 28 cycles. In studies 2 and 3, enamel specimens were treated with 20 min cycles of either XW or water and exposed to whole saliva at all other times. In study 3, an additional exposure to a fluoride containing toothpaste was conducted. In total, 28 treatments were conducted in order to simulate a 2 weeks product use. In study 4, dentine specimens were treated as per study 3. Final microhardness measurements were taken and for studies 3 and 4 colour measurements were additionally taken. XW and water gave no statistically significant (p>0.05) changes in enamel and dentine microhardness after 28 treatments. Sprite Light gave a significant (p<0.00002) reduction in enamel microhardness after one 20 min treatment. XW showed significant bleaching of enamel and dentine specimens as compared to the water control. XW does not have any significant effect on enamel and dentine microhardness.

Bioactive glass for dentin remineralization: A systematic review.

PubMed

Fernando, Delihta; Attik, Nina; Pradelle-Plasse, Nelly; Jackson, Phil; Grosgogeat, Brigitte; Colon, Pierre

2017-07-01

Strategies to achieve dentin remineralization is at present an important target of restorative dentistry. Remineralization of dentin by a bioactive material is complete only when the tissue regains its functionality. This is achieved when there is adequate apatite formation which most importantly translates into improved mechanical properties of dentin as a result of intrafibrillar mineralization. Bioactive glass (BAG) is a well-known implant material for bone regeneration and is proven to have excellent ability of apatite formation. Hence, recent studies have proposed BAGs as one of the most desired materials for remineralization of dentin. Therefore the aim of this systematic review was to scope the evidence of bioactive glass to remineralize dentin. The following research question was formulated: "Is there strong evidence for bioactive glass to remineralize dentin?" Three databases (Web of science, PubMed and Science direct) were scanned independently following PRISMA guidelines. Inclusion and exclusion criteria were set to identify relevant articles based on title and abstract screening. Finally, potentially relevant articles were downloaded and the full text was scrutinized to select the articles included in this review. The first phase of search returned 303 articles. A total of 19 papers with full text were scrutinized for inclusion, of which 3 papers were chosen for the final synthesis. All three studies confirm that BAG treatment leads to enhanced apatite formation in dentin. Only 1 of the 3 studies has reported the mechanical properties of dentin after BAG treatment and it revealed that the Young's modulus and flexural bend strength of BAG treated dentin were much lower than natural dentin even though they had similar apatite content. This review highlights the importance of assessing the mechanical properties of dentin alongside to the newly formed apatite content in order to prove BAGs efficiency to remineralize this tissue. Though studies have confirmed that BAGs stimulate excellent apatite formation in dentin, it should be concluded that there isn't sufficient evidence for bioactive glass to effectively remineralize this tissue as the mechanical properties of the BAG treated dentin haven't been well explored. Copyright © 2017 Elsevier B.V. All rights reserved.

Clinical Evaluation of Nd:YAG and 685-nm Diode Laser Therapy for Desensitization of Teeth with Gingival Recession

PubMed Central

Canakci, Varol; Ozdemir, Atilla; Kaya, Yavuz

2009-01-01

Abstract Objectives: The aim of this study was to evaluate the effectiveness of two types of lasers, the Nd:YAG laser and the 685-nm diode laser, as dentin desensitizers as well as both the immediate and late therapeutic effects on teeth with gingival recession. Materials and Methods: The study was conducted on 56 teeth in 14 patients with Miller's class 1 and 2 gingival recession with clinically elicitable dentin hypersensitivity (DH). The patients were divided into two groups: a Nd:YAG-laser-treated group and a 685-nm diode laser-treated group. DH was assessed by means of an air stimulus, and a visual analog scale (VAS) was used to measure DH. The selected teeth in the two groups received laser therapy for three sessions. Teeth subjected to Nd:YAG-laser treatment were irradiated at 1 W and 10 Hz for 60 sec at 1064 nm, and those receiving 685-nm diode laser treatment were irradiated at 25 mW and 9 Hz for 100 sec. Results: Significant reductions in DH occurred at all time points measured during the three treatment sessions in both treatment groups. Comparing the means of the responses in the three treatment sessions for the two groups revealed that the Nd:YAG laser group had a higher degree of desensitization compared to the other group (p < 0.01). The immediate and late therapeutic effects of the Nd:YAG laser were more evident than those of the 685-nm diode laser. Conclusions: Both of these lasers can be used to reduce DH without adverse effects. Desensitization of teeth with gingival recession with the Nd:YAG laser was more effective than with the diode laser. The Nd:YAG laser appears to be a promising new tool for successfully reducing DH. PMID:19281413

Effect of smear layer deproteinization on bonding of self-etch adhesives to dentin: a systematic review and meta-analysis

PubMed Central

Alshaikh, Khaldoan H.; Mahmoud, Salah H.

2018-01-01

Objectives The aim of this systematic review was to critically analyze previously published studies of the effects of dentin surface pretreatment with deproteinizing agents on the bonding of self-etch (SE) adhesives to dentin. Additionally, a meta-analysis was conducted to quantify the effects of the above-mentioned surface pretreatment methods on the bonding of SE adhesives to dentin. Materials and Methods An electronic search was performed using the following databases: Scopus, PubMed and ScienceDirect. The online search was performed using the following keywords: ‘dentin’ or ‘hypochlorous acid’ or ‘sodium hypochlorite’ and ‘self-etch adhesive.’ The following categories were excluded during the assessment process: non-English articles, randomized clinical trials, case reports, animal studies, and review articles. The reviewed studies were subjected to meta-analysis to quantify the effect of the application time and concentration of sodium hypochlorite (NaOCl) and hypochlorous acid (HOCl) deproteinizing agents on bonding to dentin. Results Only 9 laboratory studies fit the inclusion criteria of this systematic review. The results of the meta-analysis revealed that the pooled average microtensile bond strength values to dentin pre-treated with deproteinizing agents (15.71 MPa) was significantly lower than those of the non-treated control group (20.94 MPa). Conclusions In light of the currently available scientific evidence, dentin surface pretreatment with deproteinizing agents does not enhance the bonding of SE adhesives to dentin. The HOCl deproteinizing agent exhibited minimal adverse effects on bonding to dentin in comparison with NaOCl solutions. PMID:29765895

The effect of silver fluoride and potassium iodide on the bond strength of auto cure glass ionomer cement to dentine.

PubMed

Knight, G M; McIntyre, J M; Mulyani

2006-03-01

Diamine silver fluoride (Ag(NH3)2F), referred to as AgF, has been shown to reduce the incidence of caries in primary dentitions. The clinical application of this material has been limited by staining associated with both teeth and restorative materials. The application of potassium iodide (KI) after AgF eliminates stain formation. There is a lack of information as to how the addition of AgF followed by KI may affect the bond strength to dentine. The purpose of this study was to compare the bond strengths of auto cure glass ionomer cement to dentine surfaces that had been treated with AgF and KI and without treatment. Ten recently extracted human third molars were embedded into methyl methacrylate resin and sliced to form a square block of exposed dentine surfaces. Each of the four surfaces were treated by one of the following procedures: (a) etching with 37 per cent phosphoric acid; (b) applying GC dentine conditioner; (c) etching, followed by application of AgF/KI then washing off the precipitate and air drying; and (d) etching, applying AgF/KI and air drying the reaction products on the surface. Fuji VII auto cure glass ionomer cement was bonded onto each sample and fracture tested. The dentine samples treated with AgF/KI followed by washing away the precipitate and air drying had bond strengths (2.83 MPa) not significantly different from samples that had been conditioned (2.40 MPa). Samples where the AgF/KI precipitate had been air dried onto the dentine surface had significantly lower bond strengths (1.49 MPa) than the washed samples. Samples that were etched had significantly lower bond strengths (1.91MPa) than the conditioned samples. This study found that the application of AgF/KI to etched dentine samples followed by washing off the precipitate, created bond strengths that were not significantly different to conditioned samples. Leaving the AgF/KI precipitate on the dentine surface significantly reduced the bond strength of auto cured glass ionomer cement to dentine. Washing away the reaction products and air drying is recommended as the clinical protocol for using AgF and KI on dentine surfaces prior to application of an auto cure glass ionomer cement.

Carboplatin Hypersensitivity Reactions in Pediatric Low Grade Glioma Are Protocol Specific and Desensitization Shows Poor Efficacy.

PubMed

Dodgshun, Andrew J; Hansford, Jordan R; Cole, Theresa; Choo, Sharon; Sullivan, Michael J

2016-01-01

The use of carboplatin for the treatment of pediatric low grade gliomas (PLGG) is often limited by the development of carboplatin hypersensitivity. Reported rates of carboplatin hypersensitivity reactions vary between 6% and 32% in these patients. Here we report the frequency of carboplatin hypersensitivity reactions depending on the treatment regimen used, and outcomes of carboplatin desensitization. The records of all patients in a single institution who were treated with carboplatin for PLGG were accessed and all patients receiving more than one dose of carboplatin are reported. Thirty four patients with PLGG were treated with carboplatin according to one of the two different regimens. Carboplatin hypersensitivity was documented in 47% of patients, but the frequency differed by treatment protocol. Those patients treated with 4-weekly single agent carboplatin had carboplatin allergy in 8% of cases whereas 68% of those treated with combined carboplatin and vincristine (every three weeks, according to the SIOP 2004 low grade glioma protocol) had carboplatin reactions (OR 23.6, P < 0.01). Desensitization was only successful in two out of 10 patients in whom it was attempted. Hypersensitivity reactions to carboplatin are more common in this cohort than previously reported and rates are protocol-dependent. Desensitization showed limited effectiveness in this cohort. © 2015 Wiley Periodicals, Inc.

Is dental erosion really a problem?

PubMed

Schlueter, N; Jaeggi, T; Lussi, A

2012-09-01

Dental erosion is the non-carious dental substance loss induced by direct impact of exogenous or endogenous acids. It results in a loss of dental hard tissue, which can be serious in some groups, such as those with eating disorders, in patients with gastroesophageal reflux disease, and also in persons consuming high amounts of acidic drinks and foodstuffs. For these persons, erosion can impair their well-being, due to changes in appearance and/or loss of function of the teeth, e.g., the occurrence of hypersensitivity of teeth if the dentin is exposed. If erosion reaches an advanced stage, time- and money-consuming therapies may be necessary. The therapy, in turn, poses a challenge for the dentist, particularly if the defects are diagnosed at an advanced stage. While initial and moderate defects can mostly be treated non- or minimally invasively, severe defects often require complex therapeutic strategies, which often entail extensive loss of dental hard tissue due to preparatory measures. A major goal should therefore be to diagnose dental erosion at an early stage, to avoid functional and esthetic impairments as well as pain sensations and to ensure longevity of the dentition.

Anti-proteolytic capacity and bonding durability of proanthocyanidin-biomodified demineralized dentin matrix

PubMed Central

Liu, Rui-Rui; Fang, Ming; Zhang, Ling; Tang, Cheng-Fang; Dou, Qi; Chen, Ji-Hua

2014-01-01

Our previous studies showed that biomodification of demineralized dentin collagen with proanthocyanidin (PA) for a clinically practical duration improves the mechanical properties of the dentin matrix and the immediate resin–dentin bond strength. The present study sought to evaluate the ability of PA biomodification to reduce collagenase-induced biodegradation of demineralized dentin matrix and dentin/adhesive interfaces in a clinically relevant manner. The effects of collagenolytic and gelatinolytic activity on PA-biomodified demineralized dentin matrix were analysed by hydroxyproline assay and gelatin zymography. Then, resin-/dentin-bonded specimens were prepared and challenged with bacterial collagenases. Dentin treated with 2% chlorhexidine and untreated dentin were used as a positive and negative control, respectively. Collagen biodegradation, the microtensile bond strengths of bonded specimens and the micromorphologies of the fractured interfaces were assessed. The results revealed that both collagenolytic and gelatinolytic activity on demineralized dentin were notably inhibited in the PA-biomodified groups, irrespective of PA concentration and biomodification duration. When challenged with exogenous collagenases, PA-biomodified bonded specimens exhibited significantly less biodegradation and maintained higher bond strengths than the untreated control. These results suggest that PA biomodification was effective at inhibiting proteolytic activity on demineralized dentin matrix and at stabilizing the adhesive/dentin interface against enzymatic degradation, is a new concept that has the potential to improve bonding durability. PMID:24810807

Triple Antibiotic Polymer Nanofibers for Intracanal Drug Delivery: Effects on Dual Species Biofilm and Cell Function

PubMed Central

Pankajakshan, Divya; Albuquerque, Maria T.P.; Evans, Joshua D.; Kamocka, Malgorzata M.; Gregory, Richard L.; Bottino, Marco C.

2016-01-01

Introduction Root canal disinfection and the establishment of an intracanal microenvironment conducive to the proliferation/differentiation of stem cells play a significant role in regenerative endodontics. This study was designed to (1) investigate the antimicrobial efficacy of triple antibiotic–containing nanofibers against a dual-species biofilm and (2) evaluate the ability of dental pulp stem cells (DPSCs) to adhere to and proliferate on dentin upon nanofiber exposure. Methods Seven-day-old dual-species biofilm established on dentin specimens was exposed for 3 days to the following: saline (control), antibiotic-free nanofibers (control), and triple antibiotic–containing nanofibers or a saturated triple antibiotic paste (TAP) solution (50 mg/mL in phosphate buffer solution). Bacterial viability was assessed using the LIVE/DEAD assay (Molecular Probes, Inc, Eugene, OR) and confocal laser scanning microscopy. For cyto-compatibility studies, dentin specimens after nanofiber or TAP (1 g/mL in phosphate buffer solution) exposure were evaluated for cell adhesion and spreading by actin-phalloidin staining. DPSC proliferation was assessed on days 1, 3, and 7. Statistics were performed, and significance was set at the 5% level. Results Confocal laser scanning microscopy showed significant bacterial death upon antibiotic-containing nanofiber exposure, differing significantly (P < .05) from antibiotic-free fibers and the control (saline). DPSCs showed enhanced adhesion/spreading on dentin specimens treated with antibiotic-containing nanofibers when compared with its TAP counterparts. The DPSC proliferation rate was similar on days 1 and 3 in antibiotic-free nanofibers, triple antibiotic–containing nanofibers, and TAP-treated dentin. Proliferation was higher (9-fold) on dentin treated with antibiotic-containing nanofibers on day 7 compared with TAP. Conclusions Triple antibiotic–containing polymer nanofibers led to significant bacterial death, whereas they did not affect DPSC attachment and proliferation on dentin. PMID:27663615

Mini-interfacial Fracture Toughness of a Multimode Adhesive Bonded to Plasma-treated Dentin.

PubMed

Ayres, Ana Paula Almeida; Pongprueksa, Pong; De Munck, Jan; Gré, Cristina Parise; Nascimento, Fábio Dupart; Giannini, Marcelo; Van Meerbeek, Bart

2017-01-01

To investigate the bonding efficacy of a multimode adhesive to plasma-treated and -untreated (control) dentin using a mini-interfacial fracture toughness (mini-iFT) test. Twenty human molars were used in a split-tooth design (n = 10). The adhesive Scotchbond Universal (SBU; 3M ESPE) was applied in etch-and-rinse (E&R) and self-etch (SE) modes. Mid-coronal dentin was exposed and covered with a standardized smear layer ground to 320 grit. One half of each dentin surface received 15 s of non-thermal atmospheric plasma (NTAP), while the other half was covered with a metallic barrier and kept untreated. Following the E&R mode, dentin was plasma treated immediately after phosphoric acid etching. SBU and a resin-based composite were applied to dentin following the manufacturer's instructions. Six mini-iFT specimens were prepared per tooth (1.5 x 2.0 x 16 to 18 mm), and a single notch was prepared at the adhesive-dentin interface using a 150-μm diamond blade under water cooling. Half of the mini-iFT specimens were immediately loaded until failure in a 4-point bending test, while the other half were first stored in distilled water for 6 months. After testing, the exact dimensions of the notch were measured with a measuring optical microscope, from which ΚIc was determined. Three-way ANOVA revealed higher mini-iFT for SBU applied in E&R than SE mode for both storage times, irrespective of NTAP treatment. Overall, mini-iFT did not decrease for any of the experimental groups upon 6-month aging, while plasma treatment did not show a direct beneficial effect on mini-iFT of SBU applied in either E&R or SE mode.

Effects of potassium oxalate on knoop hardness of etch-and-rinse adhesives.

PubMed

Silva, S M A; Malacarne-Zanon, J; Carvalho, R M; Alves, M C; De Goes, M F; Anido-Anido, A; Carrilho, M R

2012-01-01

The objective of this study was to determine whether the hardness of etch-and-rinse adhesives may be affected by the pretreatment of acid-etched dentin with potassium oxalate desensitizer. Unerupted human third molars were cut into crown segments by removing the occlusal enamel and roots. The pulp chamber of these crown segments was connected to a syringe barrel filled with phosphate-buffered saline so that the moisture of dentin was maintained during the bonding procedures. Three etch-and-rinse adhesives-two two-step systems (Adper Single Bond 2 [SB], One-Step [OS]) and one three-step system (Adper Scotchbond Multi-Purpose [MP])-were applied to acid-etched dentin that had been treated (experimental groups) or not (control groups) with potassium oxalate (BisBlock). The Knoop hardness (KHN) of adhesives was taken at different sites of the outer surface of the adhesive-bonded dentin. The KHN of the three tested adhesives applied to acid-etched dentin treated with potassium oxalate was significantly lower than that exhibited by the respective controls (not treated with oxalate; p<0.05). Regardless of the adhesive, the treatment with potassium oxalate reduced the adhesives' KHN (p<0.05), with the OS system exhibiting the lowest KHN compared with the MP and SB systems.

[Influence of carbodiimide-ethanol solution surface treatment on dentin microtensile bond strength].

PubMed

Zhang, Yi; Liu, Yu-hua; Zhou, Yong-sheng; Chung, Kwok-hung

2015-10-18

To evaluate the microtensile bond strength changes and patterns of fractures of the bonding interface after dentine surface treatment with carbodiimide-ethanol solution. 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) dissolved in ethanol was diluted into different concentrations of 2, 1, 0.3, 0.1 and 0.01 mol/L EDC-ethanol solutions. Twenty-eight caries-free extracted human third molars were ground metallurgically to prepare flat occlusal mid-coronal dentin surfaces and etched with 35% (mass fraction) phosphoric acid gel. Then they were treated with EDC-ethanol solution for 60 s before the bonding procedure and randomly divided into five experimental groups corresponding to the tested EDC-ethanol concentrations. The ethanol treated and no pre-treated surfaces were used as controls. Single Bond 2 adhesive was applied and resin composite disk was stacked on the treated dentine surface. The teeth with resin composite disks were stored in water at room temperature for 24 h and then sectioned longitudinally to produce stick specimens for microtensile bond strength test. Fracture patterns were observed with a stereomicroscope. The dentin surfaces pre-treated with 2 mol/L [(22.17±13.31) MPa] and 1 mol/L [(45.31±17.80) MPa] EDC-ethanol solutions resulted in statistically significant lower bond strength value (P<0.05). Increasing numbers of fracture pattern at the resin-dentin interface were also found in this two groups with percentages of 81.2% and 41.3% respectively. No significant difference was observed in the groups with 0.3, 0.1, 0.01 mol/L EDC surface treatment (P>0.05). No significant difference of immediate bond strengths was found in the 0.3, 0.1, 0.01 mol/L groups compared with the control group. EDC-ethanol solution surface treatment with concentrations of 2 mol/L and 1 mol/L resulted in decreasing of the bonding strength.

Clinical evaluation of the Jay Sensitivity Sensor Probe: a new microprocessor-controlled instrument to evaluate dentin hypersensitivity.

PubMed

Sowinski, Joseph A; Kakar, Ashish; Kakar, Kanupriya

2013-05-01

To compare the Jay Sensitivity Sensor Probe (Jay Probe), a new microprocessor-based, pre-calibrated instrument, with well accepted methods used to evaluate sensitivity, i.e. tactile response to the Yeaple Probe, air blast (Schiff scale), and patient responses by Visual Analog Score (VAS). Jay Probe assessments were accomplished using several approaches. With a cohort of 12 subjects, two clinical examiners compared the repeatability of the Jay and Yeaple Probes. A second evaluation of both probes was conducted during two independent parallel design clinical studies each enrolling 100 adults with dentin hypersensitivity (DH). In each study, subjects were evaluated for DH responses after twice daily oral hygiene with a negative control fluoride dentifrice or a positive control dentifrice formulated with ingredients proven to reduce sensitivity, i.e. potassium nitrate or 8.0% arginine with calcium carbonate. Tactile evaluations by the Jay and Yeaple Probes were conducted at baseline and recall visits over the 8-week duration of each study. Also evaluated at each visit were responses to air blast and to patient reported DH assessment by VAS. Low inter-examiner variability with no significant differences between replicate measurements (P > 0.05) was observed with the Jay Probe. Consistent with results from previous studies, subjects assigned dentifrices formulated with potassium nitrate or 8% arginine/calcium carbonate demonstrated improvements in Yeaple, air blast and VAS responses in comparison to those assigned the fluoride dentifrice (P < 0.05). Jay Probe responses correlated significantly with all other sensitivity measures (P < 0.05). Differences between these treatments were observed at all post-treatment evaluations using these methods.

Prevalence of dentine hypersensitivity and study of associated factors: a European population-based cross-sectional study.

PubMed

West, Nicola Xania; Sanz, Mariano; Lussi, Adrian; Bartlett, David; Bouchard, Phillipe; Bourgeois, Denis

2013-10-01

Dentine hypersensitivity (DH) manifests as a transient but arresting oral pain. The incidence is thought to be rising, particularly in young adults, due to increases in consumption of healthy, yet erosive, diets. This study aimed to assess the prevalence of DH and relative importance of risk factors, in 18-35 year old Europeans. In 2011, 3187 adults were enrolled from general dental practices in France, Spain, Italy, United Kingdom, Finland, Latvia and Estonia. DH was clinically evaluated by cold air tooth stimulation, patient pain rating (yes/no), accompanied by investigator pain rating (Schiff 0-3). Erosive toothwear (BEWE index 0-3) and gingival recession (mm) were recorded. Patients completed a questionnaire regarding the nature of their DH, erosive dietary intake and toothbrushing habits. 41.9% of patients reported pain on tooth stimulation and 56.8% scored ≥1 on Schiff scale for at least one tooth. Clinical elicited sensitivity was closely related to Schiff score and to a lesser degree, questionnaire reported sensitivity (26.8%), possibly reflecting the transient nature of the pain, alongside good coping mechanisms. Significant associations were found between clinically elicited DH and erosive toothwear and gingival recession. The questionnaire showed marked associations between DH and risk factors including heartburn/acid reflux, vomiting, sleeping medications, energy drinks, smoking and acid dietary intake. Overall, the prevalence of DH was high compared to many published findings, with a strong, progressive relationship between DH and erosive toothwear, which is important to recognise for patient preventive therapies and clinical management of DH pain. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of the Ratio between Pigment and Bleaching Gel on the Fracture Resistance and Dentin Microhardness of endodontically treated Teeth.

PubMed

Galloza, Marina Og; Jordão-Basso, Keren Cf; Bandeca, Matheus C; Costa, Samuel O; Borges, Alvaro H; Tonetto, Mateus R; Tirintan, Fabio C; Keine, Kátia C; Kuga, Milton C

2017-11-01

The aim of this study was to evaluate the effects of bleaching gel using 35% hydrogen peroxide (HP), associated with red carmine pigment (RC), in the 3:1 or 1:1 ratio, on fracture resistance and dentin microhardness of endodontically treated teeth. A total of 40 lower incisors were endodontically treated and divided into four groups (n = 10), according to the bleaching protocol: G1 (HP3), 35% HP + RC (3:1); G2 (HP1), 35% HP + RC (1:1); G3 (positive), 38% HP; and G4 (negative), unbleached. Four dental bleaching sessions were performed. The dental crowns were restored after the last session and submitted to the fracture resistance test. Totally, 60 specimens from the endodontically treated lower incisor crowns were prepared to evaluate the effects on dentin microhardness. The analysis was measured (in Knoop) prior to and after the last dental bleaching session using similar bleaching protocols. G2 presented the lowest fracture resistance (p < 0.05). The other groups were similar to each other (p > 0.05). No difference was observed in the reduction of dentin microhardness among the groups (p > 0.05). A 1:1 ratio (bleaching gel:pigment) caused a significant fracture resistance reduction in relation to the other protocols. No effect on the dentin microhardness reduction was observed. The pigment addition to the bleaching agent accelerates the bleaching chemical reaction. However, no studies have evaluated the ideal proportion to optimize tooth bleaching.

Morphological and chemical characterization of the dentin/resin cement interface produced with a self-etching primer.

PubMed

Walker, Mary P; Wang, Yong; Spencer, Paulette

2002-01-01

The purpose of this study was to analyze a resin cement/dentin interface by comparing the diffusion of a resin cement into dentin surfaces pretreated with a self-etching primer with or without pretreatment by conventional acid etching. Dentin surfaces of 8 unerupted human third molars were treated with a self-etch primer (Panavia 21) with or without conventional phosphoric acid pretreatment. Panavia 21 resin cement was applied according to manufacturer's instructions. Dentin/resin cement interface sections from each tooth were examined with scanning electron microscopy and micro-Raman spectroscopy. When the self-etch primer was used following conventional acid pretreatment, the resin cement did not penetrate to the depth of the zone of demineralized dentin, leaving a substantial area of exposed dentin matrix at the dentin/cement interface. In contrast, there was substantial resin cement diffusion throughout the demineralized dentin when the self-etch primer was used without acid etching pretreatment. The in vitro evaluation of resin cement penetration throughout the zone of demineralized dentin is an important step in identifying sites of exposed dentin matrix that may promote postoperative sensitivity and may leave the dentin/resin cement interface vulnerable to premature degradation under clinical conditions. In this study, the self-etch primer used alone produced substantial resin cement penetration and left no exposed dentin matrix at the dentin/resin cement interface.

Efficacy of different whitening modalities on bovine enamel and dentin.

PubMed

Wiegand, Annette; Vollmer, Doreen; Foitzik, Magdalena; Attin, Rengin; Attin, Thomas

2005-06-01

Previous studies have shown that bleaching treatment may be efficient in both enamel and dentin, but it is still unknown how much the subsurface dentin contributes to the color change of teeth. This in vitro study evaluated the whitening effect of different external bleaching agents on enamel-dentin slabs and subsurface dentin. Ninety bovine teeth were distributed among six groups (A, Opalescence 10%; B, Opalescence PF 15%; C, Opalescence Quick; D, Opalescence Extra Boost; E, Rapid White; F, Whitestrips). Two enamel-dentin specimens were prepared from the labial surface of each teeth. In one of the specimens enamel was removed, resulting in a dentin (CD) disc of 1 mm high. The labial and the pulpal sides of the second specimen were ground until the remaining enamel and dentin layers of the enamel-dentin sample (ED) were 1 mm each. Whitening treatment of the ED specimens was performed according to manufacturers' instructions. Pre- and posttreatment Lab values of ED samples were analyzed using CIE-Lab. Baseline Lab values of dentin were analyzed by evaluation of the CD specimen. Finally, enamel of the ED specimens was removed and color change of the exposed dentin (D) was recorded. For all treatment agents significant color changes (DeltaE) were observed for enamel-dentin samples and subsurface dentin specimens compared to controls. In groups A-D DeltaE was significantly higher in dentin than enamel-dentin. Furthermore, L and b values of bleached enamel-dentin and subsurface dentin samples differed significantly from baseline. Treatment with the tested external whitening bleaching agents resulted in color change of both enamel-dentin and subsurface dentin samples. The results indicate that color change of treated teeth might be highly influenced by color change of the subsurface dentin.

An in-vitro evaluation of the effect of 980 nm diode laser irradiation on intra-canal dentin surface and dentinal tubule openings after biomechanical preparation: Scanning electron microscopic study

PubMed Central

Jhingan, Pulkit; Sandhu, Meera; Jindal, Garima; Goel, Deepti; Sachdev, Vinod

2015-01-01

Context: Very recently, diode laser has been used for disinfecting the root canals in endodontic treatment and increasing its success rate and longevity utilizing the thermal effect of laser on surrounding tissues. Aims: The aim of this study is to evaluate the effect of 980 nm laser irradiation on intra-canal dentin surface – scanning electron microscopic (SEM) - in-vitro study. Methods: A total of 40 single-rooted freshly extracted permanent teeth were collected. Teeth were sectioned at the cemento-enamel junction using diamond disc. Root canals of all samples were prepared using hand ProTaper, which were randomly assigned into two groups (n = 20 each). Group 1: Receiving no treatment after biomechanical preparation; Group 2: 980 nm diode laser-treated root canals. Teeth were prepared for SEM analysis to check the size of intra-canal dentinal tubule openings. Statistical Analysis Used: Data were analyzed using SPSS V.16 software and compared using Levene's and independent t-test. Results: On statistical analysis, width of intracanal dentinal tubule openings in Group 1 (control) was significantly higher than those observed in Group 2 (diode laser-treated) (P < 0.001). Conclusion: This study showed that the application of 980 nm diode laser on intra-radicular dentin resulted in ultrastructural alterations resulting in melting of dentin. PMID:26097338

Management of trichomonas vaginalis in women with suspected metronidazole hypersensitivity.

PubMed

Helms, Donna J; Mosure, Debra J; Secor, W Evan; Workowski, Kimberly A

2008-04-01

Standard treatment for Trichomonas vaginalis is metronidazole or tinidazole. Hypersensitivity to these drugs has been documented but is poorly understood. Desensitization is an option described in limited reports of women with hypersensitivity to nitroimidazoles. The purpose of this analysis is to improve documentation of management for trichomonas infections among women with metronidazole hypersensitivity. Clinicians who consulted Centers for Disease Control and Prevention concerning patients with suspected hypersensitivity to metronidazole were provided with treatment options and asked to report outcomes. From September 2003-September 2006, complete information was obtained for 59 women. The most common reactions were urticaria (47%) and facial edema (11%). Fifteen of these women (25.4%) were treated with metronidazole desensitization and all had eradication of their infection. Seventeen women (28.8%) were treated with alternative intravaginal drugs, which were less successful; 5 of 17 infections (29.4%) were eradicated. Metronidazole desensitization was effective in the management of women with nitroimidazole hypersensitivity.

Systematic review finds that silver diamine fluoride is effective for both root caries prevention and arrest in older adults.

PubMed

McReynolds, David; Duane, Brett

2018-06-01

Data sourcesPubMed, Pubmed Clinical Queries, EMBASE, the American Dental Associations Evidence-Based Dentistry Website, Cochrane Library, Web of Science, repository of the Journal of the American Dental Association and Google Scholar.Study selectionFour authors independently assessed the abstracts of studies resulting from the above searches which compared treatment of root caries in an older population with SDF versus other preventive agents or placebos.Data extraction and synthesisTitles and abstracts of all reports identified through the electronic searches were assessed independently by four authors based on agreed upon inclusion and exclusion criteria. Of the selected studies for final inclusion in the systematic review, study quality was assessed using the critical appraisal worksheet for randomised controlled trials from the Oxford Centre for Evidence-Based Medicine (CEBM 2005). Prevented fraction (PF), number needed to treat (NNT) and relative risk (RR) were calculated as outcome measures in each study. In addition, the published evidence on SDF was reviewed in order to formulate clinical recommendations on safety and effectiveness when treating root or coronal caries in an adult population with SDF, as well as treatment of dental hypersensitivity.ResultsThree randomised controlled trials were identified that addressed the effectiveness of SDF on root caries in older adults, but none addressed coronal caries. Root caries prevented fraction and arrest rate for SDF were significantly higher than placebo. The prevented fraction for caries prevention for SDF compared to placebo was 71% in a three-year study and 25% in a two-year study. The prevented fraction for caries arrest for SDF was 725% greater in a 24-month study and 100% greater than placebo in a 30-month study. No severe adverse effects were observed.ConclusionsExisting reports of SDF trials support effectiveness in root caries prevention and arrest, remineralisation of deep occlusal lesions and treatment of hypersensitive dentine.

Influence of phosphoproteins' biomimetic analogs on remineralization of mineral-depleted resin-dentin interfaces created with ion-releasing resin-based systems.

PubMed

Sauro, Salvatore; Osorio, Raquel; Watson, Timothy F; Toledano, Manuel

2015-07-01

The study aimed at evaluating the remineralization of acid-etched dentin pre-treated with primers containing biomimetic analogs and bonded using an ion-releasing light-curable resin-based material. An experimental etch-and-rinse adhesive system filled with Ca(2+), PO4(3-)-releasing Ca-Silicate micro-fillers was created along with two experimental primers containing biomimetic analogs such as sodium trimetaphosphate (TMP) and/or polyaspartic acid (PLA). Dentin specimens etched with 37% H3PO4 were pre-treated with two different aqueous primers containing the polyanionic biomimetic analogs or deionized water and subsequently bonded using the experimental resin-based materials. The specimens were sectioned and analyzed by AFM/nanoindentation to evaluate changes in the modulus of elasticity (Ei) across the resin-dentin interface at different AS storage periods (up to 90 days). Raman cluster analysis was also performed to evaluate the chemical changes along the interface. The phosphate uptake by the acid-etched dentin was evaluated using the ATR-FTIR. Additional resin-dentin specimens were tested for microtensile bond strength. SEM examination was performed after de-bonding, while confocal laser microscopy was used to evaluate the interfaces ultramorphology and micropermeability. Both biomimetic primers induced phosphate uptake by acid-etched dentin. Specimens created with the ion-releasing resin in combination with the pre-treatment primers containing either PLA and TMA showed the greatest recovery of the Ei of the hybrid layer, with no decrease in μTBS (p>0.05) after 3-month AS storage. The ion-releasing resin applied after use of the biomimetic primers showed the greatest reduction in micropermeability due to mineral precipitation; these results were confirmed using SEM. The use of the ion-releasing resin-based system applied to acid-etched dentin pre-treated with biomimetic primers containing analogs of phosphoproteins such as poly-l-aspartic acid and/or sodium trimetaphosphate provides a suitable bonding approach for biomimetic remineralization of resin-dentin interfaces. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Effects of acid etching and adhesive treatments on host-derived cysteine cathepsin activity in dentin.

PubMed

Zhang, Wenhao; Yang, Weixiang; Wu, Shuyi; Zheng, Kaibin; Liao, Weili; Chen, Boli; Yao, Ke; Liang, Guobin; Li, Yan

2014-10-01

To analyze the effects of different processes during bonding on endogenous cysteine cathepsin activity in dentin. Dentin powder, prepared from extracted human third molars, was divided into 10 groups. Two lots of dentin powder were used to detect the effects of the procedure of protein extraction on endogenous cathepsin activity. The others were used to study effects of different acid-etching or adhesive treatments on enzyme activity. Concentrations of 37% phosphoric acid or 10% phosphoric acid, two etch-and-rinse adhesive systems, and two self-etching adhesive systems were used as dentin powder treatments. The untreated mineralized dentin powder was set as the control. After treatment, the proteins of each group were extracted. The total cathepsin activity in the extracts of each group was monitored with a fluorescence reader. In the control group, there were no significant differences in cathepsin activity between the protein extract before EDTA treatment and the protein extract after EDTA treatment (p > 0.05). The cathepsin activities of the three different extracts in the 37% phosphoric acid-treated group were different from each other (p < 0.05). The two acid-etching groups and two etch-and-rinse groups showed significant enzyme activity reduction vs the control group (p < 0.05). There were no significant differences between those four groups (p > 0.05). Treating the dentin powder with any of the two self-etching adhesives resulted in an increase in cathepsin activity (p < 0.05). The activity of cysteine cathepsins can be detected in dentin powder. Treatment with EDTA during protein extraction exerted an influence on cathepsin activity. Acid etching or etch-and-rinse adhesive systems may reduce the activity of endogenous cathepsins in dentin. Self-etching adhesive systems may increase the enzyme activity.

Dental Pulp and Dentin Tissue Engineering and Regeneration – Advancement and Challenge

PubMed Central

Huang, George T.-J.

2012-01-01

Hard tissue is difficult to repair especially dental structures. Tooth enamel is incapable of self-repairing whereas dentin and cememtum can regenerate with limited capacity. Enamel and dentin are commonly under the attack by caries. Extensive forms of caries destroy enamel and dentin and can lead to dental pulp infection. Entire pulp amputation followed by the pulp space disinfection and filled with an artificial rubber-like material is employed to treat the infection --commonly known as root canal or endodontic therapy. Regeneration of dentin relies on having vital pulps; however, regeneration of pulp tissue has been difficult as the tissue is encased in dentin without collateral blood supply except from the root apical end. With the advent of modern tissue engineering concept and the discovery of dental stem cells, regeneration of pulp and dentin has been tested. This article will review the recent endeavor on pulp and dentin tissue engineering and regeneration. The prospective outcome of the current advancement and challenge in this line of research will be discussed. PMID:21196351

Acute hypersensitivity reactions associated with administration of crotalidae polyvalent immune Fab antivenom.

PubMed

Cannon, Robert; Ruha, Anne-Michelle; Kashani, John

2008-04-01

Acute hypersensitivity reactions are well known to occur with the administration of the Antivenin (Crotalidae) Polyvalent (Wyeth Laboratories, Marietta, PA). Crotalidae polyvalent immune Fab (ovine) (CroFab; FabAV, Protherics, Inc., Brentwood, TN) was introduced in 2001, and early studies reported a hypersensitivity reaction rate up to 19%. We describe the incidence of acute hypersensitivity reactions to FabAV in patients bitten by rattlesnakes. This was a nonconcurrent observational cohort study, with data obtained by chart review of all patients admitted to our service for rattlesnake bites from July 2000 to June 2004. The study was conducted at an urban Level I trauma center and urban children's hospital. All patients treated with FabAV were included. Those who received no antivenom or who were treated with Antivenin (Crotalidae) Polyvalent were excluded. The main outcome variable was whether an acute hypersensitivity reaction developed. Ninety-three patients were included in the review (72 male and 21 female patients). The mean age was 34.5 years (range 16 months to 91 years), and the mean dose of antivenom was 12 vials (range 4 to 32 vials). The incidence of acute hypersensitivity reactions was 5 of 93, or 5.4%. Four patients developed a mild reaction that was easily treated and were able to finish the full course of antivenom. Only 1 patient developed a reaction that prevented further antivenom administration. FabAV appears to be associated with a lower incidence of acute hypersensitivity than initially reported. Most reactions are mild and easily treated and do not preclude further dosing of antivenom.

Long-term effect of diode laser irradiation compared to sodium fluoride varnish in the treatment of dentine hypersensitivity in periodontal maintenance patients: a randomized controlled clinical study.

PubMed

Yilmaz, Hasan Guney; Kurtulmus-Yilmaz, Sevcan; Cengiz, Esra

2011-11-01

The aim of this clinical study was to evaluate and compare the desensitizing effects of a gallium?aluminum?arsenide (GaAlAs) laser and sodium fluoride (NaF) varnish on dentine hypersensitivity (DH) in periodontal maintenance patients. The use of lasers opens a new dimension in the treatment of DH. Forty-eight patients with 244 teeth affected by DH were included in the trial. To be included in the study, the subjects had to have 4 or more hypersensitive teeth at different quadrants. Selected teeth were randomly assigned to a GaAlAs laser group, placebo laser group, NaF varnish group, or a placebo NaF varnish group. Laser therapy was performed at 8.5?J/cm(2) energy density. In the placebo laser group, the same laser without laser emission was used. In the NaF varnish group, the varnish was painted at the cervical region of the teeth. In the placebo NaF varnish group, the same treatment procedures were performed with a saline solution. DH was assessed with a visual analog scale (VAS); immediately, at 1 week, and at 1, 3, and 6 months after treatments. Intra-group time-dependent data were analyzed by Friedman's test, and Wilcoxon's rank sum test was used to evaluate the differences within groups. GaAlAs laser and NaF varnish treatments resulted in a significant reduction in the VAS scores immediately after treatments that were maintained throughout the study when compared to the baseline and placebo treatments. In the NaF group, there was a significant increase in the VAS scores at 3 and 6 months compared to at 1 week and 1 month. The placebo treatments showed no significant changes in VAS scores throughout the study period. Within the limits of the study, GaAlAs laser irradiation was effective in the treatment of DH, and it is a more comfortable and faster procedure than traditional DH treatment.

Chlorhexidine binding to mineralized versus demineralized dentin powder

PubMed Central

Kim, Jongryul; Uchiyama, Toshikazu; Carrilho, Marcela; Agee, Kelli A.; Mazzoni, Annalisa; Breschi, Lorenzo; Carvalho, Ricardo M.; Tjäderhane, Leo; Looney, Stephen; Wimmer, Courtney; Tezvergil-Mutluay, Arzu; Tay, Franklin R.; Pashley, David H.

2010-01-01

Objectives The purposes of this work were to quantitate the affinity and binding capacity of chlorhexidine (CHX) digluconate to mineralized vs. demineralized dentin powder, and to determine how much debinding would result from rinsing with water, ethanol, hydroxyethylmethacrylate (HEMA) or 0.5 M NaCl in water. Methods Dentin powder was made from coronal dentin of extracted human third molars. Standard amounts of dentin powder were tumbled with increasing concentrations of CHX (0–30 mM) for 30 min at 37 C. After centrifuging the tubes, the supernatant was removed and the decrease in CHX concentration quantitated by UV-spectroscopy. CHX-treated dentin powder was resuspended in one of the four debinding solutions for 3 min. The amount of debound CHX in the solvents was also quantitated by UV-spectroscopy. Results As the CHX concentration in the medium increased, the CHX binding to mineralized dentin powder also increased up to 6.8 μmoles/g of dry dentin powder. Demineralized dentin powder took up significantly (p<0.01) more CHX, reaching 30.1 μmoles CHX/g of dry dentin powder. Debinding of CHX was in the order: HEMA < ethanol < 0.05 M NaCl < water. The highest CHX binding to demineralized dentin occurred at 30 mM (1.5 wt%). Significance As CHX is not debound by HEMA, it may remain bound to demineralized dentin during resin-dentin bonding. This may be responsible for the long-term efficacy of CHX as an MMP inhibitor in resin-dentin bonds. PMID:20472280

Advanced zinc-doped adhesives for high performance at the resin-carious dentin interface.

PubMed

Toledano, Manuel; Osorio, Raquel; Osorio, Estrella; García-Godoy, Franklin; Toledano-Osorio, Manuel; Aguilera, Fátima S

2016-09-01

The purpose of this study was to evaluate the remineralization ability of an etch-and-rinse Zn-doped resin applied on caries-affected dentin (CAD). CAD surfaces were subjected to: (i) 37% phosphoric acid (PA) or (ii) 0.5M ethylenediaminetetraacetic acid (EDTA). 10wt% ZnO nanoparticles or 2wt% ZnCl2 were added into the adhesive Single Bond (SB), to create the following groups: PA+SB, PA+SB-ZnO, PA+SB-ZnCl2, EDTA+SB, EDTA+SB-ZnO, EDTA+SB-ZnCl2. Bonded interfaces were submitted to mechanical loading or stored during 24h. Remineralization of the bonded interfaces was studied by AFM nano-indentation (hardness and Young׳s modulus), Raman spectroscopy [mapping with principal component analysis (PCA), and hierarchical cluster analysis (HCA)] and Masson׳s trichrome staining technique. Dentin samples treated with PA+SB-ZnO attained the highest values of nano-mechanical properties. Load cycling increased both mineralization and crystallographic maturity at the interface; this effect was specially noticed when using ZnCl2-doped resin in EDTA-treated carious dentin. Crosslinking attained higher frequencies indicating better conformation and organization of collagen in specimens treated with PA+SB-ZnO, after load cycling. Trichrome staining technique depicted a deeper demineralized dentin fringe that became reduced after loading, and it was not observable in EDTA+SB groups. Multivariate analysis confirmed de homogenizing effect of load cycling in the percentage of variances, traces of centroids and distribution of clusters, especially in specimens treated with EDTA+SB-ZnCl2. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of a pulsed Nd:YAG laser on enamel and dentin

NASA Astrophysics Data System (ADS)

Myers, Terry D.

1990-06-01

Enamel and dentin samples were exposed extraorally to a pulsed neodymium yttriuma1uminumgarnet (Nd:YAG) laser. The lased samples were observed using both scanning electron microscopy and histological techniques to determine the effects of the laser. The present study has provided the following points: (1) Properly treated, enamel can be 1aser etched to a depth comparable to that achieved with phosphoric acid etching; and (2) both carious and noncarious dentin can be vaporized by the Nd:YAG laser. No cracking or chipping of any enamel or dentin sample was observed histologically or under the SEM.

Effect of Er,Cr:YSGG laser on the microtensile bond strength of two different adhesives to the sound and caries-affected dentin.

PubMed

Ergücü, Z; Celik, E U; Unlü, N; Türkün, M; Ozer, F

2009-01-01

This study examined the effect of Er,Cr:YSGG laser irradiation on the microtensile bond strength (microTBS) of a three-step etch-and-rinse and a two-step self-etch adhesive to sound and caries-affected dentin. Sixteen freshly extracted human molars with occlusal dentin caries were used. The caries lesion was removed by one of the following methods: conventional treatment with burs or Er,Cr:YSGG laser (Waterlase MD, Biolase). The adhesive systems (AdheSE, Ivoclar Vivadent and Scotchbond Multi Purpose, 3M ESPE) were applied to the entire tooth surface according to the manufacturers' instructions. Resin composites were applied to the adhesive-treated dentin surfaces and light-cured. Each tooth was sectioned into multiple beams with the "non-trimming" version of the microtensile test. The specimens were subjected to microtensile forces (BISCO Microtensile Tester, BISCO). The data was analyzed by three-way ANOVA and independent t-tests (p=0.05). Er,Cr:YSGG laser irradiation exhibited similar microTBS values compared to that of conventional bur treatment, regardless of the adhesive system and type of treated dentin. The self-etch system revealed lower microTBS values, both with conventional and laser treatment techniques, compared to the etch-and-rinse adhesive in sound and caries-affected dentin (p<0.05). Er,Cr:YSGG laser irradiation did not negatively affect the bonding performance of adhesive systems to sound and caries-affected dentin.

Outcome of pediatric patients with acute lymphoblastic leukemia/lymphoblastic lymphoma with hypersensitivity to pegaspargase treated with PEGylated Erwinia asparaginase, pegcrisantaspase: A report from the Children's Oncology Group

PubMed Central

Rau, Rachel E.; Dreyer, ZoAnn; Choi, Mi Rim; Liang, Wei; Skowronski, Roman; Allamneni, Krishna P.; Devidas, Meenakshi; Raetz, Elizabeth A.; Adamson, Peter C.; Blaney, Susan M.; Loh, Mignon L; Hunger, Stephen P.

2018-01-01

Background Erwinia asparaginase is a Food and Drug Administration approved agent for the treatment of acute lymphoblastic leukemia (ALL) for patients who develop hypersensitivity to Escherichia coli derived asparaginases. Erwinia asparaginase is efficacious, but has a short half-life, requiring six doses to replace one dose of the most commonly used first-line asparaginase, pegaspargase, a polyethylene glycol (PEG) conjugated E. coli asparaginase. Pegcristantaspase, a recombinant PEGylated Erwinia asparaginase with improved pharmacokinetics, was developed for patients with hypersensitivity to pegaspargase. Here, we report a series of patients treated on a pediatric phase 2 trial of pegcrisantaspase. Procedure Pediatric patients with ALL or lymphoblastic lymphoma and hypersensitivity to pegaspargase enrolled on Children's Oncology Group trial AALL1421 (Jazz 13-011) and received intravenous pegcrisantaspase. Serum asparaginase activity (SAA) was monitored before and after dosing; immunogenicity assays were performed for antiasparaginase and anti-PEG antibodies and complement activation was evaluated. Results Three of the four treated patients experienced hypersensitivity to pegcrisantaspase manifested as clinical hypersensitivity reactions or rapid clearance of SAA. Immunogenicity assays demonstrated the presence of anti-PEG immunoglobulin G antibodies in all three hypersensitive patients, indicating a PEG-mediated immune response. Conclusions This small series of patients, nonetheless, provides data, suggesting preexisting immunogenicity against the PEG moiety of pegaspargase and poses the question as to whether PEGylation may be an effective strategy to optimize Erwinia asparaginase administration. Further study of larger cohorts is needed to determine the incidence of preexisting antibodies against PEG-mediated hypersensitivity to pegaspargase. PMID:29090524

Repair of dentin defects from DSPP knockout mice by PILP mineralization

PubMed Central

Nurrohman, H.; Saeki, K.; Carneiro, K.; Chien, Y.C.; Djomehri, S.; Ho, S.P.; Qin, C.; Marshall, S.J.; Gower, L.B.; Marshall, G.W.; Habelitz, S.

2016-01-01

Dentinogenesis imperfecta type II (DGI-II) lacks intrafibrillar mineral with severe compromise of dentin mechanical properties. A Dspp knockout (Dspp−/−) mouse, with a phenotype similar to that of human DGI-II, was used to determine if poly-L-aspartic acid [poly(ASP)] in the “polymer-induced liquid-precursor” (PILP) system can restore its mechanical properties. Dentin from six-week old Dspp−/− and wild-type mice was treated with CaP solution containing poly(ASP) for up to 14 days. Elastic modulus and hardness before and after treatment were correlated with mineralization from Micro x-ray computed tomography (Micro-XCT). Transmission electron microscopy (TEM)/Selected area electron diffraction (SAED) were used to compare matrix mineralization and crystallography. Mechanical properties of the Dspp−/− dentin were significantly less than wild-type dentin and recovered significantly (P < 0.05) after PILP-treatment, reaching values comparable to wild-type dentin. Micro-XCT showed mineral recovery similar to wild-type dentin after PILP-treatment. TEM/SAED showed repair of patchy mineralization and complete mineralization of defective dentin. This approach may lead to new strategies for hard tissue repair. PMID:27239097

Analysis of the Color and Fluorescence Alterations of Enamel and Dentin Treated With Hydrogen Peroxide.

PubMed

Caneppele, Taciana Marco Ferraz; Rocha Gomes Torres, Carlos; Bresciani, Eduardo

2015-10-01

The aim of this study was to evaluate the effect of hydrogen peroxide whitening on fluorescence and color of bovine enamel and dentin. Twenty five dentin discs and 25 enamel discs, with 6 mm diameter and 1 mm thick, were obtained. Direct fluorescence (spectrofluorophotometry) and color (spectrophotometry) were assessed. After fluorescence and color baseline measurements, specimens were immersed in a 35% hydrogen peroxide (HP) solution for 1 h. This procedure was repeated after 7 days. Final fluorescence and color measurements were performed after the second immersion. Chemical characterization of 5 additional specimens was also performed. Data were submitted to repeated analysis of variance and Tukey's test for fluorescence and unpaired t-test for color and chemical components (p<0.05). Fluorescence decreased significantly in dentin specimens after whitening. Enamel presented lower fluorescence than dentin at baseline, but this parameter did not decrease after whitening. Color changes were observed for both substrates, with significantly greater whitening effect in dentin (ΔE=10.37) (p<0.001). Whitening by hydrogen peroxide induced significant decrease in fluorescence of tooth dentin and promoted significant color changes in dentin and enamel with more accentuated outcomes in dentin.

Triple Antibiotic Polymer Nanofibers for Intracanal Drug Delivery: Effects on Dual Species Biofilm and Cell Function.

PubMed

Pankajakshan, Divya; Albuquerque, Maria T P; Evans, Joshua D; Kamocka, Malgorzata M; Gregory, Richard L; Bottino, Marco C

2016-10-01

Root canal disinfection and the establishment of an intracanal microenvironment conducive to the proliferation/differentiation of stem cells play a significant role in regenerative endodontics. This study was designed to (1) investigate the antimicrobial efficacy of triple antibiotic-containing nanofibers against a dual-species biofilm and (2) evaluate the ability of dental pulp stem cells (DPSCs) to adhere to and proliferate on dentin upon nanofiber exposure. Seven-day-old dual-species biofilm established on dentin specimens was exposed for 3 days to the following: saline (control), antibiotic-free nanofibers (control), and triple antibiotic-containing nanofibers or a saturated triple antibiotic paste (TAP) solution (50 mg/mL in phosphate buffer solution). Bacterial viability was assessed using the LIVE/DEAD assay (Molecular Probes, Inc, Eugene, OR) and confocal laser scanning microscopy. For cytocompatibility studies, dentin specimens after nanofiber or TAP (1 g/mL in phosphate buffer solution) exposure were evaluated for cell adhesion and spreading by actin-phalloidin staining. DPSC proliferation was assessed on days 1, 3, and 7. Statistics were performed, and significance was set at the 5% level. Confocal laser scanning microscopy showed significant bacterial death upon antibiotic-containing nanofiber exposure, differing significantly (P < .05) from antibiotic-free fibers and the control (saline). DPSCs showed enhanced adhesion/spreading on dentin specimens treated with antibiotic-containing nanofibers when compared with its TAP counterparts. The DPSC proliferation rate was similar on days 1 and 3 in antibiotic-free nanofibers, triple antibiotic-containing nanofibers, and TAP-treated dentin. Proliferation was higher (9-fold) on dentin treated with antibiotic-containing nanofibers on day 7 compared with TAP. Triple antibiotic-containing polymer nanofibers led to significant bacterial death, whereas they did not affect DPSC attachment and proliferation on dentin. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Combining Bioactive Multifunctional Dental Composite with PAMAM for Root Dentin Remineralization

PubMed Central

Xiao, Shimeng; Liang, Kunneng; Weir, Michael D.; Cheng, Lei; Liu, Huaibing; Zhou, Xuedong; Ding, Yi; Xu, Hockin H. K.

2017-01-01

Objectives. The objectives of this study were to: (1) develop a bioactive multifunctional composite (BMC) via nanoparticles of amorphous calcium phosphate (NACP), 2-methacryloyloxyethyl phosphorylcholine (MPC), dimethylaminohexadecyl methacrylate (DMAHDM) and nanoparticles of silver (NAg); and (2) investigate the effects of combined BMC + poly (amido amine) (PAMAM) on remineralization of demineralized root dentin in a cyclic artificial saliva/lactic acid environment for the first time. Methods. Root dentin specimens were prepared and demineralized with 37% phosphoric acid for 15 s. Four groups were prepared: (1) root dentin control; (2) root dentin with BMC; (3) root dentin with PAMAM; (4) root dentin with BMC + PAMAM. Specimens were treated with a cyclic artificial saliva/lactic acid regimen for 21 days. Calcium (Ca) and phosphate (P) ion concentrations and acid neutralization were determined. The remineralized root dentin specimens were examined via hardness testing and scanning electron microscopy (SEM). Results. Mechanical properties of BMC were similar to commercial control composites (p = 0.913). BMC had excellent Ca and P ion release and acid-neutralization capability. BMC or PAMAM alone each achieved slight mineral regeneration in demineralized root dentin. The combined BMC + PAMAM induced the greatest root dentin remineralization, and increased the hardness of pre-demineralized root dentin to match that of healthy root dentin (p = 0.521). Significance. The excellent root dentin remineralization effects of BMC + PAMAM were demonstrated for the first time. BMC + PAMAM induced effective and complete root dentin remineralization in an acid challenge environment. The novel BMC + PAMAM method is promising for Class V and other restorations to remineralize and protect tooth structures. PMID:28772450

Combining Bioactive Multifunctional Dental Composite with PAMAM for Root Dentin Remineralization.

PubMed

Xiao, Shimeng; Liang, Kunneng; Weir, Michael D; Cheng, Lei; Liu, Huaibing; Zhou, Xuedong; Ding, Yi; Xu, Hockin H K

2017-01-22

Objectives . The objectives of this study were to: (1) develop a bioactive multifunctional composite (BMC) via nanoparticles of amorphous calcium phosphate (NACP), 2-methacryloyloxyethyl phosphorylcholine (MPC), dimethylaminohexadecyl methacrylate (DMAHDM) and nanoparticles of silver (NAg); and (2) investigate the effects of combined BMC + poly (amido amine) (PAMAM) on remineralization of demineralized root dentin in a cyclic artificial saliva/lactic acid environment for the first time. Methods . Root dentin specimens were prepared and demineralized with 37% phosphoric acid for 15 s. Four groups were prepared: (1) root dentin control; (2) root dentin with BMC; (3) root dentin with PAMAM; (4) root dentin with BMC + PAMAM. Specimens were treated with a cyclic artificial saliva/lactic acid regimen for 21 days. Calcium (Ca) and phosphate (P) ion concentrations and acid neutralization were determined. The remineralized root dentin specimens were examined via hardness testing and scanning electron microscopy (SEM). Results . Mechanical properties of BMC were similar to commercial control composites ( p = 0.913). BMC had excellent Ca and P ion release and acid-neutralization capability. BMC or PAMAM alone each achieved slight mineral regeneration in demineralized root dentin. The combined BMC + PAMAM induced the greatest root dentin remineralization, and increased the hardness of pre-demineralized root dentin to match that of healthy root dentin ( p = 0.521). Significance . The excellent root dentin remineralization effects of BMC + PAMAM were demonstrated for the first time. BMC + PAMAM induced effective and complete root dentin remineralization in an acid challenge environment. The novel BMC + PAMAM method is promising for Class V and other restorations to remineralize and protect tooth structures.

Evaluation of sub-surface penetration and bonding durability of self-etching primer systems to Er:YAG laser treated cervical dentin.

PubMed

He, Zhengdi; Chen, Lingling; Shimada, Yasushi; Tagami, Junji; Ruan, Shuangchen

2017-03-31

This study aimed to investigate self-etching bonding systems penetrating in sub-surface dentin layer after Er:YAG laser irradiation and micro-shear bonding durability over a period of 1 year. Dentin slices obtained from extracted human third molars were prepared. Two self-etching adhesive systems were evaluated: Clearfil SE Bond and Clearfil Tri-S Bond. Specimens were tested for micro-shear bond strength with one of the following treatments: Er:YAG laser irradiation and 600-grit silicon paper polishing at 24 h, 7 days, 6 months and 1 year. The adhesive interfaces between bonding agents and lased cervical dentin were studied. No hybrid layer could be observed for lased dentin. The slim resin tags could be seen penetrating through the lased subsurface layer. Bond strength to lased dentin after 6 months and 1 year were significantly decreased (p<0.05).

Ex vivo fracture resistance of endodontically treated maxillary central incisors restored with fiber-reinforced composite posts and experimental dentin posts

PubMed Central

Kathuria, Ambica; Kavitha, M; Khetarpal, Suchit

2011-01-01

Aim: To compare the fracture resistance of teeth restored with fiber-reinforced composite (FRC) posts and experimental dentin posts milled from human root dentin. Materials and Methods: Thirty maxillary central incisors were divided into three groups of ten each. Twenty teeth were restored with FRC posts and solid dentin posts and numbered as Groups 2 and 3 respectively while Group 1 acted as the control, without any post. The teeth were loaded at 135° angle to their long axes after core build-up and the failure loads were recorded. Results: One-way Analysis of Variance (ANOVA) and Bonferroni multiple comparisons revealed a significant difference among test groups with the control group showing the highest fracture resistance, followed by the dentin post group and lastly the FRC post group. Conclusions: Teeth restored with dentin posts exhibited better fracture resistance than those restored with FRC posts. PMID:22144812

Efficiency of Lasers and a Desensitizer Agent on Dentin Hypersensitivity Treatment: A Clinical Study.

PubMed

Ozlem, K; Esad, G M; Ayse, A; Aslihan, U

2018-02-01

The aim of this clinical study was to determine and compare the efficiency of the glutaraldehyde-containing agent (GCA), Nd:YAG, Er,Cr:YSGG lasers, and the combination of them on the dentin hypersensitivity (DH) treatment. This study was performed with the participation of 17 healthy adult patients having 100 teeth with DH; the patients were randomly divided into five groups according to the treatment protocol: (1) application of GCA on sensitive teeth, (2) Nd:YAG laser (1 W/cm 2 , 10 Hz) irradiation on sensitive teeth, (3) application of GCA on sensitive teeth and then Nd:YAG laser irradiation, (4) Er,Cr:YSGG laser (0.25 W/cm 2 , 20 Hz) irradiation on sensitive teeth, (5) application of GCA on sensitive teeth and then Er,Cr:YSGG laser irradiation. Sensitivity levels were assessed by the Yeaple probe on the buccal surfaces of the teeth at a force setting of 10 g. Measurements were performed for 30 min, after 7, 90, and 180 days of the therapy to assess the effects of desensitization. The evaluations were analyzed using the one-way analysis of variance and repeated measurement test (P < 0.05). After sessions, DH was significantly reduced in all groups at each measurement point. The Er,Cr:YSGG laser with or without GCA application were the most effective ones in DH treatment (P < 0.05). Comparison of the treatment regimens demonstrated that the scores achieved with the Yeaple probe were not significantly higher for the Nd:YAG laser groups than the GCA alone group. This clinical study shows that the Er,Cr:YSGG laser have promising potential for the treatment of DH.

Pre-treating dentin with chlorhexadine and CPP-ACP: self-etching and universal adhesive systems

PubMed Central

dos Santos, Ricardo Alves; de Lima, Eliane Alves; Montes, Marcos Antônio Japiassu Resende; Braz, Rodivan

2016-01-01

Abstract Objective: The aim of the present study was to compare the effect of pre-treating dentin with chlorhexidine, at concentrations of 0.2% and 2%, and remineralizing paste containing CPP-ACP (MI Paste – GC) on the bond strength of adhesive systems. Material and methods: In total, 80 slides of dentin were used. These slides were 2 mm thick and were obtained from bovine incisors. Standard cavities were created using diamond bur number 3131. In the control groups, a Scotchbond Universal Adhesive (SUA) self-etching adhesive system of 3M ESPE and a Clearfil SE Bond (CSE) adhesive system of Kuraray were applied, following the manufacturer’s instructions. In the other groups, dentin was pretreated with chlorhexidine (0.2% and 2%) for 1 min and with MI Paste for 3 min. The cavities were restored with Z350 XT resin (3M ESPE). After 24 h of storage, the push-out test was applied at a speed of 0.5 mm/min. Results: The different dentin pretreatment techniques did not affect the intra-adhesive bond strength. There was a difference between treatment with MI Paste and chlorhexidine 0.2% in favor of the SUA, with values of 15.22 and 20.25 Mpa, respectively. Conclusions: The different pretreatment methods did not alter the immediate bond strength to dentin. Differences were only recorded when comparing the adhesives. PMID:28642915

Pre-treating dentin with chlorhexadine and CPP-ACP: self-etching and universal adhesive systems.

PubMed

Dos Santos, Ricardo Alves; de Lima, Eliane Alves; Montes, Marcos Antônio Japiassu Resende; Braz, Rodivan

2016-12-01

Objective: The aim of the present study was to compare the effect of pre-treating dentin with chlorhexidine, at concentrations of 0.2% and 2%, and remineralizing paste containing CPP-ACP (MI Paste - GC) on the bond strength of adhesive systems. Material and methods: In total, 80 slides of dentin were used. These slides were 2 mm thick and were obtained from bovine incisors. Standard cavities were created using diamond bur number 3131. In the control groups, a Scotchbond Universal Adhesive (SUA) self-etching adhesive system of 3M ESPE and a Clearfil SE Bond (CSE) adhesive system of Kuraray were applied, following the manufacturer's instructions. In the other groups, dentin was pretreated with chlorhexidine (0.2% and 2%) for 1 min and with MI Paste for 3 min. The cavities were restored with Z350 XT resin (3M ESPE). After 24 h of storage, the push-out test was applied at a speed of 0.5 mm/min. Results: The different dentin pretreatment techniques did not affect the intra-adhesive bond strength. There was a difference between treatment with MI Paste and chlorhexidine 0.2% in favor of the SUA, with values of 15.22 and 20.25 Mpa, respectively. Conclusions: The different pretreatment methods did not alter the immediate bond strength to dentin. Differences were only recorded when comparing the adhesives.

Aspects of dentinal and pulpal pain. Pain of dentinal and pulpal origin--a review for the clinician.

PubMed

Figdor, D

1994-04-01

Recent advances in understanding the mechanisms of pain arising from the dental pulp serve to benefit patients by improving the clinician's ability to diagnose and treat pain. There are two types of pain arising from the pulp which are mediated by entirely different nerve fibres, each with their own individual characteristics. One is a short, sharp fast pain which is induced by stimuli which cause a rapid fluid flow within the dentinal tubules. Such stimuli include cold, heat, air, drilling, and osmotic stimuli. Once the affected teeth are identified, they can often be treated by sealing the open, exposed dentine. The second type of pain is experienced as a slow, dull, aching, poorly localized pain which is mediated by pain fibres activated by stimuli which are noxious to the pulp, such as prolonged damaging heat and inflammatory mediators. Pain of this character can be difficult to diagnose and often indicates serious pulp damage necessitating removal of the offending pulp by endodontic therapy.

Wettability of root canal sealers on intraradicular dentine treated with different irrigating solutions.

PubMed

Ballal, Nidambur Vasudev; Tweeny, Adlyn; Khechen, Khaled; Prabhu, K Narayan; Satyanarayan; Tay, Franklin R

2013-06-01

The aim of this in vitro study was to evaluate the wettability of AH Plus and ThermaSeal Plus sealers on intraradicular dentine treated with different irrigating solutions. Fifty anterior teeth were decoronated and split longitudinally. Each root half was divided into 5 groups (n=10). Group I: 5mL of 2.5% NaOCl+QMix. Group II: 5mL of 2.5% NaOCl+17% EDTA. Group III: 5mL of 2.5% NaOCl+7% maleic acid. Group IV: 5mL of 2.5% NaOCl. Group V: 5mL of distilled water. Irrigation regimens were performed for 1min. Each specimen was placed inside a Dynamic Contact Angle Analyser. A controlled-volume droplet of sealer was placed on each specimen and the static contact angle was analysed. The contact angle made by both sealers with EDTA-irrigated dentine was significantly larger when compared to the other irrigants (P<0.05). For ThermaSeal Plus, contact angles produced on maleic acid-, NaOCl- and distilled water-irrigated dentine were not significantly different, but were all significantly larger than the contact angle produced on QMix-irrigated dentine (P<0.05). For AH Plus, contact angles produced on NaOCl- and distilled water-irrigated dentine were not significantly different, but were significantly larger than those made by maleic acid and QMix. When used as a final irrigant, QMix favours the wetting of root canal dentine by both AH Plus and ThermaSeal Plus sealers. Maleic acid shows a promising result when compared to EDTA and NaOCl. Wettability of both sealers is the worst on EDTA-irrigated dentine. The present study highlights the effect of newer endodontic irrigating solutions on the wettability of sealers on to the root canal dentine, which is required for obtaining good obturation seal. Copyright © 2013 Elsevier Ltd. All rights reserved.

Functional remineralization of carious dentin

NASA Astrophysics Data System (ADS)

Pugach, Megan Kardon

A primary goal of dental tissue engineering is the biological reconstruction of tooth substrate destroyed by caries or other diseases affecting tooth mineralization. Traditionally, dentists treat caries by using invasive techniques to remove the diseased dental tissue and restore the lesion, ideally preventing further progression of decay. Success in strategies associated with remineralization of enamel and root caries have contributed to the less invasive prospect of remineralization of dentinal carious lesions. The central hypothesis of this dissertation is that carious dentin lesions can be remineralized if the lesions contain residual mineral. Caries Detector (CD) stained zones (pink, light pink, transparent and normal) of arrested carious dentin lesions were characterized according to microstructure by atomic force microscopy (AFM) imaging, mineral content by digital transverse microradiography, and nanomechanical properties by AFM-based nanoindentation. CD-stained and unstained zones had significantly different microstructure, mineral content and nanomechanical properties. Furthermore, the most demineralized carious zone contained residual mineral. To obtain reproducible, standardized dentin caries lesions, we characterized the lesions from an artificial carious dentin lesion model using a 0.05M acetate demineralization buffer. The artificial caries-like lesions produced by the buffer had similar mineral content and nanomechanical properties in the stained and unstained zones as natural dentin lesions. Both natural and artificial lesions had significant correlations between mineral content and nanomechanical properties. Mineral crystallite size and shape was examined by small angle x-ray scattering. Both natural and artificial carious dentin had different mineral sizes than normal dentin. Collagen in natural and artificial carious dentin lesions was examined by trichrome stain, AFM high-resolution imaging, and UV resonance Raman spectroscopy, to determine if fibrils were intact and mineralization levels. It appeared that the collagen in the most demineralized pink zones of the lesions was intact and contained intrafibrillar mineral. Natural and artificial carious dentin lesions were treated with remineralization solutions containing different amounts of Ca2+ and PO 43-, with and without CO32- and with and without 2 ppm fluoride. The hydrated nanomechanical properties of the lesions were partially restored. This suggests that the most CD-stained zones of arrested dentin caries lesions may be remineralizable. These results suggest that remineralization as an approach of minimally invasive dentistry using non-invasive treatments to restore dental tissues is possible.

Antimicrobial activity of a sodium hypochlorite/etidronic acid irrigant solution.

PubMed

Arias-Moliz, Maria Teresa; Ordinola-Zapata, Ronald; Baca, Pilar; Ruiz-Linares, Matilde; Ferrer-Luque, Carmen María

2014-12-01

The aim of this study was to evaluate the antimicrobial activity of a 2.5% sodium hypochlorite (NaOCl)/9% etidronic acid (HEBP) irrigant solution on Enterococcus faecalis growing in biofilms and a dentinal tubule infection model. The antimicrobial activity of the solutions 2.5% NaOCl and 9% HEBP alone and associated was evaluated on E. faecalis biofilms grown in the Calgary biofilm model (minimum biofilm eradication concentration high-throughput device). For the dentinal tubule infection test, the percentage of dead cells in E. faecalis-infected dentinal tubules treated with the solutions for 10 minutes was measured using confocal laser scanning microscopy and the live/dead technique. Available chlorine and pH of the solutions were also measured. Distilled water was used as the control. Nonparametric tests were used to determine statistical differences. The highest viability was found in the distilled water group and the lowest in the NaOCl-treated dentin (P < .05). Both NaOCl solutions killed 100% of the E. faecalis biofilms and showed the highest antimicrobial activity inside dentinal tubules, without statistical differences between the 2 (P < .05). The HEBP isolated solution killed bacteria inside dentinal tubules but did not present any significant effect against E. faecalis biofilms. The incorporation of HEBP to NaOCl did not cause any loss of available chlorine within 60 minutes. HEBP did not interfere with the ability of NaOCl to kill E. faecalis grown in biofilms and inside dentinal tubules. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Dentin remineralization in acid challenge environment via PAMAM and calcium phosphate composite.

PubMed

Liang, Kunneng; Weir, Michael D; Xie, Xianju; Wang, Lin; Reynolds, Mark A; Li, Jiyao; Xu, Hockin H K

2016-11-01

The objective of this study was to investigate the effects of poly (amido amine) (PAMAM), composite with nanoparticles of amorphous calcium phosphate (NACP), and the combined PAMAM+NACP nanocomposite treatment, on remineralization of demineralized dentin in a cyclic artificial saliva/lactic acid environment for the first time. Dentin specimens were prepared and demineralized with 37% phosphoric acid for 15s. Four groups were prepared: (1) dentin control, (2) dentin coated with PAMAM, (3) dentin with NACP composite, (4) dentin with PAMAM+NACP. Specimens were treated with a cyclic artificial saliva/lactic acid regimen for 21days. Acid neutralization and calcium (Ca) and phosphate (P) ion concentrations were measured. The remineralized dentin specimens were examined by scanning electron microscopy (SEM) and hardness testing. NACP nanocomposite had mechanical properties similar to commercial control composites (p>0.1). NACP composite had acid-neutralization and Ca and P ion release capability. PAMAM or NACP composite each alone achieved remineralization and increased the hardness of demineralized dentin (p<0.05). PAMAM+NACP nanocomposite achieved the greatest mineral regeneration in demineralized dentin and the greatest hardness increase in demineralized dentin, which approached the hardness of healthy dentin (p>0.1). The superior remineralization efficacy of PAMAM+NACP was demonstrated for the first time. PAMAM+NACP induced remineralization in demineralized dentin in an acid challenge environment, when conventional remineralization methods such as PAMAM did not work well. The novel PAMAM+NACP composite approach is promising for a wide range of dental applications to inhibit caries and protect tooth structures. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Synthetic Hydroxyapatite as a Biomimetic Oral Care Agent.

PubMed

Enax, Joachim; Epple, Matthias

Human tooth enamel consists mostly of minerals, primarily hydroxyapatite, Ca10(PO4)6(OH)2, and thus synthetic hydroxyapatite can be used as a biomimetic oral care agent. This review describes the synthesis and characterization of hydroxyapatite from a chemist's perspective and provides an overview of its current use in oral care, with a focus on dentin hypersensitivity, caries, biofilm management, erosion, and enamel lesions. Reviews and original research papers published in English and German were included. The efficiency of synthetic hydroxyapatite in occluding open dentin tubules, resulting in a protection for sensitive teeth, has been well documented in a number of clinical studies. The first corresponding studies on caries, biofilm management and erosion have provided evidence for a positive effect of hydroxyapatite either as a main or synergistic agent in oral care products. However, more in situ and in vivo studies are needed due to the complexity of the oral milieu and to further clarify existing results. Due to its biocompatibility and similarity to biologically formed hydroxyapatite in natural tooth enamel, synthetic hydroxyapatite is a promising biomimetic oral care ingredient that may extend the scope of preventive dentistry.

Chlorhexidine stabilizes the adhesive interface: a 2 year in vitro study

PubMed Central

Breschi, Lorenzo; Mazzoni, Annalisa; Nato, Fernando; Carrilho, Marcela; Visintini, Erika; Tjäderhane, Leo; Ruggeri, Alessandra; Tay, Franklin R; De Stefano Dorigo, Elettra; Pashley, David H

2013-01-01

Objectives This study evaluated the role of endogenous dentin MMPs in auto-degradation of collagen fibrils within adhesive-bonded interfaces. The null hypotheses tested were that adhesive blends or chlorhexidine digluconate (CHX) application does not modify dentin MMPs activity and that CHX used as therapeutic primer does not improve the stability of adhesive interfaces over time. Methods Zymograms of protein extracts from human dentin powder incubated with Adper Scotchbond 1XT (SB1XT) on untreated or 0.2–2% CHX treated dentin were obtained to assay dentin MMPs activity. Microtensile bond strength and interfacial nanoleakage expression of SB1XT bonded interfaces (with or without CHX pre-treatment for 30s on the etched surface) were analyzed immediately and after 2 yr of storage in artificial saliva at 37°C. Results Zymograms showed that application of SB1XT to human dentin powder increases MMP-2 activity, while CHX pre-treatment inhibited all dentin gelatinolytic activity, irrespective from the tested concentration. CHX significantly lowered the loss of bond strength and nanoleakage seen in acid-etched resin-bonded dentin artificially aged for 2 yr. Significance The study demonstrates the active role of SB1XT in dentin MMP-2 activation and the efficacy of CHX inhibition of MMPs even if used at low concentration (0.2%). PMID:20045177

An experiment on the attrition of acid demineralized dentine in vitro.

PubMed

Li, H; Liu, M C; Deng, M; Moazzez, R; Bartlett, D W

2011-03-01

A laboratory investigation was designed to test the hypothesis that acids increase the rate of wear caused by attrition on dentine. Dentine sections from 10 teeth were polished, cleaned in an ultrasonic bath and divided into 8 equally sized areas. The occlusal tip of a tooth, placed vertically in a wear machine and loaded at 150 N, was moved against each dentine section for 5000 return strokes with artificial saliva acting as a lubricant. Each dentine section was divided into 8 sections and half randomly immersed in a 1% citric acid solution (pH 2.3) for 20 minutes. The wear regime produced 8 wear scars in total per dentine sample. The volume of each wear scar was measured using a contacting digitizing profilometer. A total of 80 wear scars were produced with 40 treated with acid and 40 acting as controls. The mean for wear volume of the dentine scars with acid was 4.84 μm(3) (1.38) and for the non-acid surface 2.95 μm(3) (0.86). This difference was statistically significant (p < 0.05). These results support the hypothesis that acids increase the rate of wear caused by attrition on dentine. © 2011 Australian Dental Association.

Efficacy of calcium oxide and calcium hydroxide nanoparticles on the elimination of Enterococcus faecalis in human root dentin.

PubMed

Louwakul, Phumisak; Saelo, Attapon; Khemaleelakul, Saengusa

2017-04-01

The objective of this study was to compare the antibacterial effect of calcium oxide nanoparticles (CONPs) and calcium hydroxide nanoparticles (CHNPs) against Enterococcus faecalis in a dentinal block model. E. faecalis strain JCM 7783 was introduced into dentinal tubules of semicylindrical dentin specimens by centrifugation and incubated for 1 week. Fifty microliters of CONPs or CHNPs was placed on the root canal side of the infected dentin specimens. The specimens were then incubated in aerobic condition at 37 °C and 100 % relative humidity for 1 week. The treated dentin specimens were subjected to fluorescent staining and confocal laser scanning microscopy (CLSM) to analyze the proportions of non-vital and vital bacterial cells inside the dentinal tubules. Scanning electron microscopy (SEM) was used to confirm the effect of the medicaments on the bacteria in the dentinal tubules. Calcium oxide (CO) and calcium hydroxide (CH) were used as controls. Based on the CLSM and SEM analyses, CHNPs were more efficient than CONPs in the elimination of the bacteria in the dentinal tubules. CONPs significantly killed more E. faecalis than CO and CH (P < .05). Neither CO nor CH was able to kill the bacteria. CHNPs were more effective than CONPs in the elimination of E. faecalis in dentinal tubules. CHNPs are effective nanoparticles in killing endodontic bacteria present in dentinal tubules. They have potential as an intracanal medicament, which may be beneficial in root canal therapy.

A Systematic Desensitization Paradigm to Treat Hypersensitivity to Auditory Stimuli in Children with Autism in Family Contexts

ERIC Educational Resources Information Center

Koegel, Robert L.; Openden, Daniel; Koegel, Lynn Kern

2004-01-01

Many children with autism display reactions to auditory stimuli that seem as if the stimuli were painful or otherwise extremely aversive. This article describes, within the contexts of three experimental designs, how procedures of systematic desensitization can be used to treat hypersensitivity to auditory stimuli in three young children with…

Microtensile bond strength of three simplified adhesive systems to caries-affected dentin.

PubMed

Scholtanus, J D; Purwanta, Kenny; Dogan, Nilgun; Kleverlaan, Cees J; Feilzer, Albert J

2010-08-01

The purpose of the study was to determine the microtensile bond strength of three different simplified adhesive systems to caries-affected dentin. Fifteen extracted human molars with primary carious lesions were ground flat until dentin was exposed. Soft caries-infected dentin was excavated with the help of caries detector dye. On the remaining hard dentin, a standardized smear layer was created by polishing with 600-grit SiC paper. Teeth were divided into three groups and treated with one of the three tested adhesives: Adper Scotchbond 1 XT (3M ESPE), a 2-step etch-andrinse adhesive, Clearfil S3 Bond (Kuraray), a 1-step self-etching or all-in-one adhesive, and Clearfil SE Bond (Kuraray), a 2-step self-etching adhesive. Five-mm-thick composite buildups (Z-250, 3M ESPE) were built and light cured. After water storage for 24 h at 37ºC, the bonded specimens were sectioned into bars (1.0 x 1.0 mm; n = 20 to 30). Microtensile bond strength of normal dentin specimens and caries-affected dentin specimens was measured in a universal testing machine (crosshead speed = 1 mm/min). Data were analyzed using two-way ANOVA and Tukey's post-hoc test (p < 0.05). No significant differences in bond strength values to normal dentin between the three adhesives were found. Adper Scotchbond 1 XT and Clearfil S3 Bond showed significantly lower bond strength values to caries-affected dentin. For Clearfil SE Bond, bond strength values to normal and caries-affected dentin were not significantly different. All the tested simplified adhesives showed similar bond strength values to normal dentin. For the tested 2-step etch-and-rinse adhesive and the all-in-one adhesive, the bond strength values to caries-affected dentin were lower than to normal dentin.

Sodium Trimetaphosphate as a Novel Strategy for Matrix Metalloproteinase Inhibition and Dentin Remineralization.

PubMed

Gonçalves, Rafael Simões; Scaffa, Polliana Mendes Candia; Giacomini, Marina Ciccone; Vidal, Cristina de Mattos Pimenta; Honório, Heitor Marques; Wang, Linda

2018-01-01

The effect of sodium trimetaphosphate (STMP) as an antiproteolytic and remineralizing agent on demineralized dentin was evaluated in vitro. The inhibitory potential of STMP at 0.5, 1.5, 3.5, and 5% against recombinant matrix metalloproteinases (MMPs) MMPs-2 and -9 was assessed by zymography. To investigate its remineralization potential, 40 bovine root specimens were obtained and subjected to a demineralization protocol to produce caries-like dentin lesions. After that, dentin surfaces were divided into 3 areas: (1) mineralized (no treatment); (2) demineralized; and (3) demineralized/treated with STMP and submitted to a pH-cycling associated or not with STMP (1.5, 3.5, or 5% STMP, 10 min of treatment). After that, superficial hardness (SH) and cross-sectional hardness (CSH) were determined. Polarized light microscopy (PLM) was used to qualitatively evaluate mineralization within the caries-like lesions. The zymographic analysis showed that STMP solution is a potent inhibitor of the gelatinolytic activity of MMPs-2 and -9 depending on the dose, since the lowest concentration (0.5%) partially inhibited the enzyme activity, while the higher concentrations completely inhibited enzyme activity. Regarding remineralization effect, only 1.5% STMP solution enhanced both the SH and CSH. PLM showed that the area treated with 1.5% STMP presented similar birefringence as mineralized sound dentin. In conclusion, 1.5% STMP solution is effective as an antiproteolytic agent against MMPs and promotes dentin remineralization. © 2018 S. Karger AG, Basel.

Influence of Bristle Stiffness of Manual Toothbrushes on Eroded and Sound Human Dentin – An In Vitro Study

PubMed Central

Arnold, Wolfgang H.; Domin, Julia

2016-01-01

Aim The aim of this study was to determine the influence of manual toothbrushes with different bristle stiffness on the abrasivity on eroded and sound human dentin. Materials and Methods Dentin specimens were made from impacted third molars and attributed to three groups: erosion-abrasion (EA), abrasion (A) and erosion (E). The specimens from EA and E were treated with 1% citric acid (pH 2.3) for 1 min rinsed, and neutralized with artificial saliva for 15 min. This cycle was repeated five times. Thereafter, specimens from EA and A were treated with three toothbrushes types with different bristle stiffness (soft, medium, and hard) in a custom-made toothbrushing machine. The brushing was performed at a load of 3 N with a toothpaste slurry for 630 s. This procedure was repeated five times, in group EA after each erosion cycle. EA and A groups passed through five cycles with a total of 6300 strokes. The abrasivity was analyzed by contact-free profilometry. Kruskal-Wallis and Mann-Whitney U tests were performed for statistical analysis. Results With respect to bristle stiffness there was no statistically significant difference in dentin loss within the EA group. In group A, a statistically significantly higher dentin loss was found for the soft in comparison to the hard bristles. No statistically significant differences were measured between soft/medium and medium/hard toothbrushes. The amount of dentin loss from specimens in the EA group was significantly higher than in the A group. Conclusions Within the limitations of this study, the dentin loss in the Abrasion group was higher with soft bristles than with hard ones. This result might have an influence on the toothbrush recommendations for patients with non-carious cervical lesions. PMID:27070901

Effects of Non-Collagenous Proteins, TGF-β1, and PDGF-BB on Viability and Proliferation of Dental Pulp Stem Cells

PubMed Central

Tabatabaei, Fahimeh Sadat

2016-01-01

ABSTRACT Objectives The dentin matrix servers as a reservoir of growth factors, sequestered during dentinogenesis. The aim of this study was to assess the viability and proliferation of dental pulp stem cells in the presence of dentin matrix-derived non-collagenous proteins and two growth factors; platelet-derived growth factor BB and transforming growth factor beta 1. Material and Methods The dental pulp cells were isolated and cultured. The dentin proteins were extracted and purified. The MTT assay was performed for assessment of cell viability and proliferation in the presence of different concentrations of dentin proteins and growth factors during 24 - 72 h post-treatment. Results The cells treated with 250 ng/mL dentin proteins had the best viability and proliferation ability in comparison with other concentrations (P < 0.05). The MTT assay demonstrated that cells cultured with 5 ng/mL platelet-derived growth factor BB had the highest viability at each time point as compared to other groups (P < 0.05). However, in presence of platelet-derived growth factor BB alone and in combination with transforming growth factor beta 1 and dentin proteins (10 ng/mL), significant higher viability was seen at all time points (P < 0.05). The least viability and proliferation at each growth factor concentration was seen in cells treated with combination of transforming growth factor beta 1 and dentin proteins at 72 h (P < 0.05). Conclusions The results indicated that the triple combination of growth factors and matrix-derived non-collagenous proteins (especially at 10 ng/mL concentration) has mitogenic effect on dental pulp stem cells. PMID:27099698

The influence of temporary cements on dental adhesive systems for luting cementation.

PubMed

Ribeiro, José C V; Coelho, Paulo G; Janal, Malvin N; Silva, Nelson R F A; Monteiro, André J; Fernandes, Carlos A O

2011-03-01

This study tested the hypothesis that bond strength of total- and self-etching adhesive systems to dentine is not affected by the presence of remnants from either eugenol-containing (EC) or eugenol-free (EF) temporary cements after standardized cleaning procedures. Thirty non-carious human third molars were polished flat to expose dentine surfaces. Provisional acrylic plates were fabricated and cemented either with EC, EF or no temporary cements. All specimens were incubated for 7 days in water at 37°C. The restorations were then taken out and the remnants of temporary cements were mechanically removed with a dental instrument. The dentine surfaces were cleaned with pumice and treated with either total-etching (TE) or self-etching (SE) dental adhesive systems. Atomic force microscopy was used to examine the presence of remnants of temporary cements before and after dentine cleaning procedures. Composite resin build-ups were fabricated and cemented to the bonded dentine surfaces with a resin luting cement. The specimens were then sectioned to obtain 0.9mm(2) beams for microtensile bond strength testing. Fractographic analysis was performed by optical and scanning electron microscopy. ANOVA showed lower mean microtensile bond strength in groups of specimens treated with EC temporary cement than in groups treated with either no cement or an EF cement (p<0.05). Mean microtensile bond strength was lower in groups employing the SE rather than the TE adhesive system (p<0.001). SE samples were also more likely to fail during initial processing of the samples. There was no evidence of interaction between cement and adhesive system effects on tensile strength. Fractographic analysis indicated different primary failure modes for SE and TE bonding systems, at the dentine-adhesive interface and at the resin cement-resin composite interface, respectively. The use of eugenol-containing temporary cements prior to indirect bonding restorations reduce, to a statistically similar extent, the bond strength of both total- and self-etching adhesive systems to dentine. Copyright © 2011 Elsevier Ltd. All rights reserved.

Oral administration of drugs with hypersensitivity potential induces germinal center hyperplasia in secondary lymphoid organ/tissue in Brown Norway rats, and this histological lesion is a promising candidate as a predictive biomarker for drug hypersensitivity occurrence in humans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tamura, Akitoshi, E-mail: akitoshi-tamura@ds-pharma.co.jp; Miyawaki, Izuru; Yamada, Toru

It is important to evaluate the potential of drug hypersensitivity as well as other adverse effects during the preclinical stage of the drug development process, but validated methods are not available yet. In the present study we examined whether it would be possible to develop a new predictive model of drug hypersensitivity using Brown Norway (BN) rats. As representative drugs with hypersensitivity potential in humans, phenytoin (PHT), carbamazepine (CBZ), amoxicillin (AMX), and sulfamethoxazole (SMX) were orally administered to BN rats for 28 days to investigate their effects on these animals by examinations including observation of clinical signs, hematology, determination ofmore » serum IgE levels, histology, and flow cytometric analysis. Skin rashes were not observed in any animals treated with these drugs. Increases in the number of circulating inflammatory cells and serum IgE level did not necessarily occur in the animals treated with these drugs. However, histological examination revealed that germinal center hyperplasia was commonly induced in secondary lymphoid organs/tissues in the animals treated with these drugs. In cytometric analysis, changes in proportions of lymphocyte subsets were noted in the spleen of the animals treated with PHT or CBZ during the early period of administration. The results indicated that the potential of drug hypersensitivity was identified in BN rat by performing histological examination of secondary lymphoid organs/tissues. Data obtained herein suggested that drugs with hypersensitivity potential in humans gained immune reactivity in BN rat, and the germinal center hyperplasia induced by administration of these drugs may serve as a predictive biomarker for drug hypersensitivity occurrence. - Highlights: • We tested Brown Norway rats as a candidate model for predicting drug hypersensitivity. • The allergic drugs did not induce skin rash, whereas D-penicillamine did so in the rats. • Some of allergic drugs increased inflammatory cells and IgE, but the others did not. • The allergic drugs commonly induced germinal center hyperplasia in lymphoid tissues. • Some of these allergic drugs transiently increased CD4{sup +}CD25{sup +} T cells in the spleen.« less

A Direct Electric Field-Aided Biomimetic Mineralization System for Inducing the Remineralization of Dentin Collagen Matrix

PubMed Central

Wu, Xiao-Ting; Mei, May Lei; Li, Quan-Li; Cao, Chris Ying; Chen, Jia-Long; Xia, Rong; Zhang, Zhi-Hong; Chu, Chun Hung

2015-01-01

This in vitro study aimed to accelerate the remineralization of a completely demineralized dentine collagen block in order to regenerate the dentinal microstructure of calcified collagen fibrils by a novel electric field-aided biomimetic mineralization system in the absence of non-collagenous proteins. Completely demineralized human dentine slices were prepared using ethylene diamine tetraacetic acid (EDTA) and treated with guanidine hydrochloride to extract the bound non-collagenous proteins. The completely demineralized dentine collagen blocks were then remineralized in a calcium chloride agarose hydrogel and a sodium hydrogen phosphate and fluoride agarose hydrogel. This process was accelerated by subjecting the hydrogels to electrophoresis at 20 mA for 4 and 12 h. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM) were used to evaluate the resultant calcification of the dentin collagen matrix. SEM indicated that mineral particles were precipitated on the intertubular dentin collagen matrix; these densely packed crystals mimicked the structure of the original mineralized dentin. However, the dentinal tubules were not occluded by the mineral crystals. XRD and EDX both confirmed that the deposited crystals were fluorinated hydroxyapatite. TEM revealed the existence of intrafibrillar and interfibrillar mineralization of the collagen fibrils. A novel electric field-aided biomimetic mineralization system was successfully developed to remineralize a completely demineralized dentine collagen matrix in the absence of non-collagenous proteins. This study developed an accelerated biomimetic mineralization system which can be a potential protocol for the biomineralization of dentinal defects. PMID:28793685

The Effect of SnCl2/AmF Pretreatment on Short- and Long-Term Bond Strength to Eroded Dentin

PubMed Central

Zumstein, Katrin; Peutzfeldt, Anne; Lussi, Adrian

2018-01-01

This study investigated the effect of SnCl2/AmF pretreatment on short- and long-term bond strength of resin composite to eroded dentin mediated by two self-etch, MDP-containing adhesive systems. 184 dentin specimens were produced from extracted human molars. Half the specimens (n = 92) were artificially eroded, and half were left untreated. For both substrates, half the specimens were pretreated with SnCl2/AmF, and half were left untreated. The specimens were treated with Clearfil SE Bond or Scotchbond Universal prior to application of resin composite. Microtensile bond strength (μTBS) was measured after 24 h or 1 year. Failure mode was detected and EDX was performed. μTBS results were statistically analyzed (α = 0.05). μTBS was significantly influenced by the dentin substrate (eroded < noneroded dentin) and storage time (24 h > 1 year; p < 0.0001) but not by pretreatment with SnCl2/AmF or adhesive system. The predominant failure mode was adhesive failure at the dentin-adhesive interface. The content of Sn was generally below detection limit. Pretreatment with SnCl2/AmF did not influence short- and long-term bond strength to eroded dentin. Bond strength was reduced after storage for one year, was lower to eroded dentin than to noneroded dentin, and was similar for the two adhesive systems.

Risk Factors of Hypersensitivity to Carboplatin in Patients with Gynecologic Malignancies

PubMed Central

Tai, Yu-Hsiao; Tai, Yi-Jou; Hsu, Heng-Cheng; Lee, Shu-Ping; Chen, Yun-Yuan; Chiang, Ying-Cheng; Chen, Yu-Li; Chen, Chi-An; Cheng, Wen-Fang

2017-01-01

We evaluated the prevalence of and risk factors for hypersensitivity reactions related to carboplatin, which is commonly used to treat gynecological malignancies. All women with pathologically documented ovarian, fallopian tube, or primary peritoneal cancer treated with carboplatin alone or a carboplatin-based combination chemotherapy regimen at a single hospital between January 2006 and December 2013 were retrospectively recruited. We analyzed the incidence, characteristics, risk factors, management, and outcomes of carboplatin-related hypersensitivity reactions among these patients. Among 735 eligible women, 75 (10.2%) experienced a total of 215 carboplatin-related hypersensitivity reaction events. The annual incidence of carboplatin-related hypersensitivity reactions gradually increased from 0.88% in 2006 to 5.42% in 2013. The incidence of carboplatin-related hypersensitivity was higher in patients with advanced stage disease (P < 0.001, Kruskal-Wallis test), serous and mixed histological types (P = 0.003, Kruskal-Wallis test), malignant ascites (P = 0.009, chi-square test), and history of other drug allergy (P < 0.001, chi-square test). Compared to women without hypersensitivity reactions, women who experienced hypersensitivity reactions had a significantly greater median cycle number (12 vs. 6, P < 0.001, independent sample t-test) and dose (6,816 vs. 3,844 mg, P < 0.001, independent sample t-test). The cumulative incidence of carboplatin-related hypersensitivity reactions dramatically increased with >8 cycles or dose >3,500 mg. Therefore, disease severity, histological type, malignant ascites, past drug allergies, and cumulative carboplatin dose are risk factors for carboplatin-related hypersensitivity reactions. Such reactions could potentially be reduced or prevented by slowing the infusion rate and using a desensitization protocol involving anti-allergy medications. PMID:29163180

Risk Factors of Hypersensitivity to Carboplatin in Patients with Gynecologic Malignancies.

PubMed

Tai, Yu-Hsiao; Tai, Yi-Jou; Hsu, Heng-Cheng; Lee, Shu-Ping; Chen, Yun-Yuan; Chiang, Ying-Cheng; Chen, Yu-Li; Chen, Chi-An; Cheng, Wen-Fang

2017-01-01

We evaluated the prevalence of and risk factors for hypersensitivity reactions related to carboplatin, which is commonly used to treat gynecological malignancies. All women with pathologically documented ovarian, fallopian tube, or primary peritoneal cancer treated with carboplatin alone or a carboplatin-based combination chemotherapy regimen at a single hospital between January 2006 and December 2013 were retrospectively recruited. We analyzed the incidence, characteristics, risk factors, management, and outcomes of carboplatin-related hypersensitivity reactions among these patients. Among 735 eligible women, 75 (10.2%) experienced a total of 215 carboplatin-related hypersensitivity reaction events. The annual incidence of carboplatin-related hypersensitivity reactions gradually increased from 0.88% in 2006 to 5.42% in 2013. The incidence of carboplatin-related hypersensitivity was higher in patients with advanced stage disease ( P < 0.001, Kruskal-Wallis test), serous and mixed histological types ( P = 0.003, Kruskal-Wallis test), malignant ascites ( P = 0.009, chi-square test), and history of other drug allergy ( P < 0.001, chi-square test). Compared to women without hypersensitivity reactions, women who experienced hypersensitivity reactions had a significantly greater median cycle number (12 vs. 6, P < 0.001, independent sample t -test) and dose (6,816 vs. 3,844 mg, P < 0.001, independent sample t -test). The cumulative incidence of carboplatin-related hypersensitivity reactions dramatically increased with >8 cycles or dose >3,500 mg. Therefore, disease severity, histological type, malignant ascites, past drug allergies, and cumulative carboplatin dose are risk factors for carboplatin-related hypersensitivity reactions. Such reactions could potentially be reduced or prevented by slowing the infusion rate and using a desensitization protocol involving anti-allergy medications.

Potential role of surface wettability on the long-term stability of dentin bonds after surface biomodification

PubMed Central

Leme, Ariene A.; Vidal, Cristina M. P.; Hassan, Lina Saleh; Bedran-Russo, Ana K.

2015-01-01

Degradation of the adhesive interface contributes to the failure of resin composite restorations. The hydrophilicity of the dentin matrix during and after bonding procedures may result in an adhesive interface that is more prone to degradation over time. This study assessed the effect of chemical modification of dentin matrix on the wettability and the long-term reduced modulus of elasticity (Er) of the adhesive interfaces. Human molars were divided into groups according to the priming solutions: distilled water (control), 6.5% Proanthocyanidin-rich grape seed extract (PACs), 5.75% 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride/1.4% n-hydroxysuccinimide (EDC/NHS) and 5% Glutaraldehyde (GA). The water-surface contact angle was verified before and after chemical modification of the dentin matrix. The demineralized dentin surface was treated with the priming solutions and restored with One Step Plus (OS) and Single Bond Plus (SB) and resin composite. The Er of the adhesive, hybrid layer and underlying dentin was evaluated after 24 h and 30 months in artificial saliva. The dentin hydrophilicity significantly decreased after application of the priming solutions. Aging significantly decreased the Er in the hybrid layer and underlying dentin of control groups. The Er of GA groups remained stable over time at the hybrid layer and underlying dentin. Significant higher Er was observed for PACs and EDC/NHS groups at the hybrid layer after 24 h. The decreased hydrophilicity of the modified dentin matrix likely influence the immediate mechanical properties of the hybrid layer. Dentin biomodification prevented substantial aging at the hybrid layer and underlying dentin after 30 months storage. PMID:25869721

Biomechanical studies on the effect of iatrogenic dentin removal on vertical root fractures.

PubMed

Ossareh, A; Rosentritt, M; Kishen, A

2018-01-01

The aim of this study was to understand the mechanism by which iatrogenic root dentin removal influences radicular stress distribution and subsequently affects the resistance to vertical root fractures (VRF) in endodontically treated teeth. The experiments were conducted in two phases. Phase 1: freshly extracted premolar teeth maintained in phosphate-buffered saline were instrumented to simulate three different degrees of dentin removal, designated as low, medium, and extreme groups. Micro-Ct analyzes were performed to quantitatively determine: (a) the amount of dentin removed, (b) the remaining dentin volume, and (c) the moment of inertia of root dentin. The specimens were then subjected to thermomechanical cycling and continuous loading to determine (a) the mechanical load to fracture and (b) dentin microcracking (fractography) using scanning electron microscopy. Phase 2: Finite element analysis was used to evaluate the influence of dentin removal on the stress distribution pattern in root dentin. The data obtained were analyzed using one-way ANOVA and Tukey's post hoc test ( P < 0.05). Phase 1: A significantly greater volume of dentin was removed from teeth in extreme group when compared to low group ( P < 0.01). The mechanical analysis showed that the load to fracture was significantly lower in teeth from extreme group ( P < 0.05). A linear relationship was observed between the moment of inertia and load to fracture in all experimental groups ( R 2 = 0.52). Fractography showed that most microcracks were initiated from the root canal walls in extreme group. Phase 2: The numerical analysis showed that the radicular stress distribution increased apically and buccolingually with greater degree of root canal dentin removal. The combined experimental/numerical analyses highlighted the influence of remaining root dentin volume on the radicular bending resistance, stress distribution pattern, and subsequent propensity to VRF.

Cariotester, a new device for assessment of dentin lesion remineralization in vitro.

PubMed

Utaka, Sachiko; Nakashima, Syozi; Sadr, Alireza; Ikeda, Masaomi; Nikaido, Toru; Shimizu, Akihiko; Tagami, Junji

2013-01-01

This study aimed to evaluate the potential of a new device (Cariotester) for monitoring of incipient carious lesion remineralization in root dentin by topical fluoride in vitro. Demineralized bovine dentin specimens were treated by fluoride solutions (APF or neutral NaF) and remineralized for 4 weeks. Cariotester was used to measure penetration depth (CTR depth) of the indenter into the de- and remineralized specimen surface. The specimens were assessed by transverse microradiography (TMR) to determine lesion parameters (depth: LD, mineral loss: ΔZ). Pearson's correlation analysis showed an overall significant relationship between CTR depth and both TMR parameters. CTR depth appeared to distinguish the positive effect that topical fluoride application had on the remineralization of the outer zone of dentin lesions. Cariotester had the potential to serve as a quantitative tool for monitoring of incipient carious lesion remineralization in root dentin.

Effect of Dentin Wetness on the Bond Strength of Universal Adhesives.

PubMed

Choi, An-Na; Lee, Ji-Hye; Son, Sung-Ae; Jung, Kyoung-Hwa; Kwon, Yong Hoon; Park, Jeong-Kil

2017-10-25

The effects of dentin wetness on the bond strength and adhesive interface morphology of universal adhesives have been investigated using micro-tensile bond strength (μTBS) testing and confocal laser scanning microscopy (CLSM). Seventy-two human third molars were wet ground to expose flat dentin surfaces. They were divided into three groups according to the air-drying time of the dentin surfaces: 0 (without air drying), 5, and 10 s. The dentin surfaces were then treated with three universal adhesives: G-Premio Bond, Single Bond Universal, and All-Bond Universal in self-etch or etch-and-rinse mode. After composite build up, a μTBS test was performed. One additional tooth was prepared for each group by staining the adhesives with 0.01 wt % of Rhodamine B fluorescent dye for CLSM analysis. The data were analyzed statistically using ANOVA and Tukey's post hoc tests (α = 0.05). Two-way ANOVA showed significant differences among the adhesive systems and dentin moisture conditions. An interaction effect was also observed ( p < 0.05). One-way ANOVA showed that All-Bond Universal was the only material influenced by the wetness of the dentin surfaces. Wetness of the dentin surface is a factor influencing the micro-tensile bond strength of universal adhesives.

Effect of Dentin Wetness on the Bond Strength of Universal Adhesives

PubMed Central

Lee, Ji-Hye; Son, Sung-Ae; Jung, Kyoung-Hwa; Kwon, Yong Hoon

2017-01-01

The effects of dentin wetness on the bond strength and adhesive interface morphology of universal adhesives have been investigated using micro-tensile bond strength (μTBS) testing and confocal laser scanning microscopy (CLSM). Seventy-two human third molars were wet ground to expose flat dentin surfaces. They were divided into three groups according to the air-drying time of the dentin surfaces: 0 (without air drying), 5, and 10 s. The dentin surfaces were then treated with three universal adhesives: G-Premio Bond, Single Bond Universal, and All-Bond Universal in self-etch or etch-and-rinse mode. After composite build up, a μTBS test was performed. One additional tooth was prepared for each group by staining the adhesives with 0.01 wt % of Rhodamine B fluorescent dye for CLSM analysis. The data were analyzed statistically using ANOVA and Tukey’s post hoc tests (α = 0.05). Two-way ANOVA showed significant differences among the adhesive systems and dentin moisture conditions. An interaction effect was also observed (p < 0.05). One-way ANOVA showed that All-Bond Universal was the only material influenced by the wetness of the dentin surfaces. Wetness of the dentin surface is a factor influencing the micro-tensile bond strength of universal adhesives. PMID:29068404

Human treated dentin matrices combined with Zn-doped, Mg-based bioceramic scaffolds and human dental pulp stem cells towards targeted dentin regeneration.

PubMed

Bakopoulou, Athina; Papachristou, Eleni; Bousnaki, Maria; Hadjichristou, Christina; Kontonasaki, Eleana; Theocharidou, Anna; Papadopoulou, Lambrini; Kantiranis, Nikolaos; Zachariadis, George; Leyhausen, Gabriele; Geurtsen, Werner; Koidis, Petros

2016-08-01

This study aimed to investigate the potential of Mg-based bioceramic scaffolds combined with human treated-dentin matrices (hTDMs) and dentinogenesis-related morphogens to promote odontogenic differentiation and dentin-like tissue formation by Dental Pulp Stem Cells-DPSCs. DPSC cultures were established and characterized by flow cytometry. Experimental cavities were prepared inside crowns of extracted teeth and demineralized by EDTA (hTDMs). Zn-doped, Mg-based bioceramic scaffolds, synthesized by the sol-gel technique, were hosted inside the hTDMs. DPSCs were spotted inside the hTDMs/scaffold constructs with/without additional exposure to DMP-1 or BMP-2 (100ng/ml, 24h). Scanning Electron Microscopy-SEM, live/dead fluorescence staining and MTT assay were used to evaluate cell attachment and viability; Real time PCR for expression of osteo/odontogenic markers; Inductively Coupled Plasma-Atomic Emission Spectrometry-ICP/AES for scaffold elemental release analysis; ELISA for hTDM growth factor release analysis; SEM and X-ray Diffraction-XRD for structural/chemical characterization of the regenerated tissues. Scaffolds constantly released low concentrations of Mg(2+), Ca(2+), Zn(2+) and Si(4+), while hTDMs growth factors, like DMP-1, BMP-2 and TGFβ-1. hTDMs/scaffold constructs supported DPSC viability, inducing their rapid odontogenic shift, indicated by upregulation of DSPP, BMP-2, osteocalcin and osterix expression. Newly-formed Ca-P tissue overspread the scaffolds partially transforming into bioapatite. Exposure to DMP-1 or BMP-2 pronouncedly enhanced odontogenic differentiation phenomena. This is the first study to validate that combining the bioactivity and ion releasing properties of bioceramic materials with growth factor release by treated natural dentin further supported by exogenous addition of key dentinogenesis-related morphogens (DMP-1, BMP-2) can be a promising strategy for targeted dentin regeneration. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Sodium Thiosulfate for Recovery of Bond Strength to Dentin Treated with Sodium Hypochlorite.

PubMed

Pimentel Corrêa, Ana Carolina; Cecchin, Doglas; de Almeida, José Flávio Affonso; Gomes, Brenda Paula Figueiredo de Almeida; Zaia, Alexandre Augusto; Ferraz, Caio Cezar Randi

2016-02-01

The aim of this study was to evaluate the efficacy of sodium thiosulfate (Na2S2O3) for restoring adhesion to pulp chamber dentin treated with sodium hypochlorite (NaOCl) and EDTA. Sixty-three crowns of bovine incisors were cut to expose the dentin pulp chamber. The specimens were polished and randomly distributed into 9 groups (n = 7) according to the following protocols used: 0.9% sodium chloride for 30 minutes (negative control), 5.25% NaOCl for 30 minutes, 17% EDTA for 3 minutes, and 5.25% NaOCl for 1 minute (positive control). The other groups, after treatments with NaOCl and EDTA, were immersed in 0.5% or 5% Na2S2O3 for 1, 5, and 10 minutes or just immersed in an inert solution for 10 minutes (0.9% sodium chloride). After drying the specimens, Scotchbond Multi-Purpose (3M ESPE, St Paul, MN) was applied to the pulp chamber dentin followed by Filtek Z250 composite (3M ESPE). Six rectangular slabs were obtained from each specimen, and the dentin/resin interface was tested by using a universal testing machine. The resulting data were submitted to 1-way analysis of variance and the Duncan test (P = .05). There was a significant decrease in bond strength regarding NaOCl and EDTA (P < .05). When 5% Na2S2O3 was used for 10 minutes, the bond strength was found to be statistically equal to the negative control and higher than the positive control (P < .05). The use of Na2S2O3 can significantly increase the bond strength of composite resin to NaOCl/EDTA-treated dentin, allowing adhesive restorations to be immediately applied after endodontic treatment. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Poly(amido amine) and calcium phosphate nanocomposite remineralization of dentin in acidic solution without calcium phosphate ions.

PubMed

Liang, Kunneng; Zhou, Han; Weir, Michael D; Bao, Chongyun; Reynolds, Mark A; Zhou, Xuedong; Li, Jiyao; Xu, Hockin H K

2017-07-01

Patients with dry mouth often have an acidic oral environment lacking saliva that provides calcium (Ca) and phosphate (P) ions. However, there has been no study on dentin remineralization by placing samples in an acidic solution without Ca and P ions. Previous studies used saliva-like solutions with neutral pH and Ca and P ions. Therefore, the objective of this study was to investigate a novel method of combining poly(amido amine) (PAMAM) with a composite of nanoparticles of amorphous calcium phosphate (NACP) on dentin remineralization in an acidic solution without Ca and P ions for the first time. Demineralized dentin specimens were tested into four groups: (1) dentin control, (2) dentin coated with PAMAM, (3) dentin with NACP nanocomposite, (4) dentin with PAMAM plus NACP composite. Specimens were treated with lactic acid at pH 4 without initial Ca and P ions for 21 days. Acid neutralization and Ca and P ion concentrations were measured. Dentin specimens were examined by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and hardness testing vs. remineralization efficacy. NACP composite had mechanical properties similar to commercial control composites (p>0.1). NACP composite neutralized acid and released Ca and P ions. PAMAM alone failed to induce dentin remineralization. NACP alone achieved mild remineralization and slightly increased dentin hardness at 21days (p>0.1). In contrast, the PAMAM+NACP nanocomposite method in acid solution without initial Ca and P ions greatly remineralized the pre-demineralized dentin, restoring its hardness to approach that of healthy dentin (p>0.1). Dentin remineralization via PAMAM+NACP in pH 4 acid without initial Ca and P ions was demonstrated for the first time, when conventional methods such as PAMAM did not work. The novel PAMAM+NACP nanocomposite method is promising to protect tooth structures, especially for patients with reduced saliva to inhibit caries. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Corticosteroid hypersensitivity studies in a skin allergy clinic.

PubMed

Berbegal, L; DeLeon, F J; Silvestre, J F

2015-12-01

Corticosteroids can cause hypersensitivity reactions, particularly delayed-type allergic reactions. A new classification system for testing hypersensitivity to corticosteroids distributes the drugs into 3 groups according to molecular structure; patients are classified according to whether they are allergic to agents in 1 or more of the groups. We aimed to describe the clinical characteristics of corticosteroid-allergic patients treated at our clinic and apply the new classification system to them; we also compared these patients' characteristics to those of others treated at our clinic. Retrospective study of cases of delayed-type corticosteroid hypersensitivity treated in the skin allergy clinic of a tertiary level hospital over an 11-year period. We reviewed the records of 2857 patients, finding 33 with at least one positive patch test result showing corticosteroid hypersensitivity. Atopic dermatitis and hand involvement were less common in our corticosteroid-allergic patients. All were allergic to a group 1 corticosteroid (most often, budesonide, the culprit in 87.9%). Testing with a specific corticosteroid series revealed that 14 (42.4%) were also allergic to corticosteroids in group 2 and/or group 3. None were allergic exclusively to group 2 or group 3 agents. Twenty-one patients were exposed to a corticosteroid cream from a group their patch test results indicated allergy to; 13 of them (61.9%) did not develop a hypersensitivity reaction. The Spanish standard series only contains group 1 corticosteroids. In the interest of improving allergy management, we recommend testing with a specific corticosteroid series and a patient's own creams whenever patch testing with a standard series reveals a hypersensitivity reaction to corticosteroids. Copyright © 2015 Elsevier España, S.L.U. and AEDV. All rights reserved.

Influence of enamel/dentin thickness on the toxic and esthetic effects of experimental in-office bleaching protocols.

PubMed

de Oliveira Duque, C C; Soares, D G; Basso, F G; Hebling, J; de Souza Costa, C A

2017-11-01

This paper aims to assess the whitening effectiveness and toxicity of tooth-bleaching protocols applied to enamel/dentin disks simulating mandibular incisors (ICs) and premolars (PMs). A 10% hydrogen peroxide (H 2 O 2 ) gel was applied for 3 × 15, 1 × 15, or 1 × 5 min to enamel/dentin disks simulating mandibular ICs and PMs, and the trans-enamel and trans-dentinal diffusion products were applied to human dental pulp cells (1 h). Professional therapy (35% H 2 O 2 -3 × 15 min) was used as positive control, and non-bleached samples were used as negative control. Cell viability and morphology, oxidative stress generation, and odontoblastic marker expression were assessed. The H 2 O 2 diffusion and enamel color change (ΔE) were also analyzed. The 10% H 2 O 2 gel induced significant cell viability reduction only when applied 3 × 15 min, with the intensity of oxidative stress and down-regulation of odontoblastic markers being higher in the IC group. The other experimental bleaching protocols caused slight alterations regarding the cell parameters evaluated, with intensity being related to enamel/dentin thickness. These effects were also correlated with higher H 2 O 2 diffusion in the IC group. ΔE values similar as positive control were found for the 10% 3 × 15 and 1 × 15 protocols on IC group, after 4 and 6 sessions. Application of a 10% H 2 O 2 bleaching gel for 15 or 45 min to thin dental substrate significantly minimizes cell toxicity in comparison with highly concentrated gels associated with similar esthetic outcomes by increasing the number of bleaching sessions. Bleaching gels with 10% H 2 O 2 applied in small teeth for short periods may be an interesting alternative to obtain whitening effectiveness without causing toxicity to pulp cells, which may be able to reduce the tooth hypersensitivity claimed by patients.

Mechanical loading influences the viscoelastic performance of the resin-carious dentin complex.

PubMed

Toledano, Manuel; Osorio, Raquel; López-López, Modesto T; Aguilera, Fátima S; García-Godoy, Franklin; Toledano-Osorio, Manuel; Osorio, Estrella

2017-04-04

The aim of this study was to evaluate the changes in the mechanical behavior and bonding capability of Zn-doped resin-infiltrated caries-affected dentin interfaces. Dentin surfaces were treated with 37% phosphoric acid (PA) followed by application of a dentin adhesive, single bond (SB) (PA+SB) or by 0.5 M ethylenediaminetetraacetic acid (EDTA) followed by SB (EDTA+SB). ZnO microparticles of 10 wt. % or 2 wt. % ZnCl 2 was added into SB, resulting in the following groups: PA+SB, PA+SB-ZnO, PA+SB-ZnCl 2 , EDTA+SB, EDTA+SB-ZnO, EDTA+SB-ZnCl 2 . Bonded interfaces were stored for 24 h, and tested or submitted to mechanical loading. Microtensile bond strength was assessed. Debonded surfaces were evaluated by scanning electron microscopy and elemental analysis. The hybrid layer, bottom of the hybrid layer, and peritubular and intertubular dentin were evaluated using a nanoindenter. The load/displacement responses were used for the nanodynamic mechanical analysis III to estimate complex modulus, tan delta, loss modulus, and storage modulus. The modulus mapping was obtained by imposing a quasistatic force setpoint to which a sinusoidal force was superimposed. Atomic force microscopy imaging was performed. Load cycling decreased the tan delta at the PA+SB-ZnCl 2 and EDTA+SB-ZnO interfaces. Tan delta was also diminished at peritubular dentin when PA+SB-ZnO was used, hindering the dissipation of energy throughout these structures. Tan delta increased at the interface after using EDTA+SB-ZnCl 2 , lowering the energy for recoil or failure. After load cycling, loss moduli at the interface decreased when using ZnCl 2 as doping agent, increasing the risk of fracture; but when using ZnO, loss moduli was dissimilarly affected if dentin was EDTA-treated. The border between intertubular and peritubular dentin attained the highest discrepancy in values of viscoelastic properties, meaning a risk for cracking and breakdown of the resin-dentin interface. PA used on dentin provoked differences in complex and storage modulus values at the intertubular and peritubular structures, and these differences were higher than when EDTA was employed. In these cases, the long-term performance of the restorative interface will be impaired.

Dentine sialoprotein and collagen I expression after experimental pulp capping in humans using emdogain gel.

PubMed

Fransson, H; Petersson, K; Davies, J R

2011-03-01

To characterize the hard tissue formed in human teeth experimentally pulp capped either with calcium hydroxide or with Emdogain Gel (Biora AB, Malmö, Sweden) - a derivative of enamel matrix (EMD), using two markers for dentine; dentine sialoprotein (DSP) and type 1 collagen (Col I). Affinity-purified rabbit anti-Col I and anti-DSP polyclonal antibodies were used to stain histological sections from nine pairs of contra-lateral premolars that had been experimentally pulp amputated and randomly capped with EMDgel or calcium hydroxide. Twelve weeks after the teeth had been pulp capped, they were extracted, fixed, demineralized and serially sectioned prior to immunohistochemical staining. In the calcium hydroxide treated teeth DSP was seen in the new hard tissue which formed a bridge. DSP was also seen in the newly formed hard tissue in the EMDgel-treated teeth. Proliferated pulp tissue partly filled the space initially occupied by EMDgel and DSP-stained hard tissue was observed alongside exposed dentine surfaces as well as in isolated masses within the proliferated pulp tissue, although the new hard tissue did not cover the pulp exposure. DSP staining was also seen in the cells lining the hard tissue in both groups. Col I staining was seen in the newly formed hard tissue in both groups. The new hard tissue formed after pulp capping with EMDgel or calcium hydroxide contained DSP and Col I, considered to be markers for dentine. Thus, the newly formed hard tissue can be characterized as dentine rather than unspecific hard tissue. © 2010 International Endodontic Journal.

Morphological alterations of radicular dentine pretreated with different irrigating solutions and irradiated with 980-nm diode laser.

PubMed

Alfredo, Edson; Souza-Gabriel, Aline E; Silva, Silvio Rocha C; Sousa-Neto, Manoel D; Brugnera-Junior, Aldo; Silva-Sousa, Yara T C

2009-01-01

The topographical features of intraradicular dentine pretreated with sodium hypochlorite (NaOCl) or ethylenediamine tetraacetic acid (EDTA) followed by diode laser irradiation have not yet been determined. To evaluate the alterations of dentine irradiated with 980-nm diode laser at different parameters after the surface treatment with NaOCl and EDTA. Roots of 60 canines were biomechanically prepared and irrigated with NaOCl or EDTA. Groups were divided according to the laser parameters: 1.5 W/CW; 1.5 W/100 Hz; 3.0 W/CW; 3.0 W/100 Hz and no irradiation (control). The roots were splited longitudinally and analyzed by scanning electron microscopy (SEM) in a quali-quatitative way. The scores were submitted to two-way Kruskal-Wallis and Dunn's tests. The statistical analysis demonstrated that the specimens treated only with NaOCl or EDTA (control groups) were statistically different (P < 0.05) from the laser-irradiated specimens, regardless of the parameter setting. The specimens treated with NaOCl showed a laser-modified surface with smear layer, fissures, and no visible tubules. Those treated with EDTA and irradiated by laser presented absence of smear layer, tubules partially exposed and melting areas. The tested parameters of 980-nm diode laser promoted similar alterations on dentine morphology, dependent to the type of surface pretreatment. Copyright 2008 Wiley-Liss, Inc.

DEGRADATION IN THE FATIGUE STRENGTH OF DENTIN BY DIAMOND BUR PREPARATIONS: IMPORTANCE OF CUTTING DIRECTION

PubMed Central

Majd, B.; Majd, H.; Porter, J.A.; Romberg, E.; Arola, D.

2014-01-01

The objectives of this investigation were to evaluate the degradation in fatigue strength of dentin by diamond bur preparations and to identify the importance of cutting direction. Three groups of coronal dentin specimens were prepared from unrestored 3rd molars, including a flaw free “control”, and two groups that received a diamond bur cutting treatment performed parallel or perpendicular to the specimen length. The specimens were subjected to static or cyclic flexural loading to failure and the results were compared with data for carbide bur cutting. Under static loading diamond bur cutting resulted in significantly flexure lower strength (p≤0.05) than the control for both cutting directions (from 154 MPa to approx. 124 MPa). However, there was no significant difference in the strength between the control and carbide bur treated specimens. Similarly, the fatigue strength of the diamond bur treated specimens was significantly lower (p≤0.0001) than that of the control for both cutting directions. Cutting in the perpendicular direction resulted in nearly 60% reduction to the endurance limit (from 44 MPa to 19 MPa). Based on the results, diamond bur cutting of cavity preparations causes a reduction in the fatigue strength of dentin, regardless of the cutting direction. To maintain the durability of dentin, cavity preparations introduced using diamond burs must be performed with appropriate cutting direction and followed by a finishing pass. PMID:25611951

Degradation in the fatigue strength of dentin by diamond bur preparations: Importance of cutting direction.

PubMed

Majd, B; Majd, H; Porter, J A; Romberg, E; Arola, D

2016-01-01

The objectives of this investigation were to evaluate the degradation in fatigue strength of dentin by diamond bur preparations and to identify the importance of cutting direction. Three groups of coronal dentin specimens were prepared from unrestored third molars, including a flaw free "control," and two groups that received a diamond bur cutting treatment performed parallel or perpendicular to the specimen length. The specimens were subjected to static or cyclic flexural loading to failure and the results were compared with data for carbide bur cutting. Under static loading diamond bur cutting resulted in significantly lower flexure strength (p ≤ 0.05) than the control for both cutting directions (from 154 to ∼124 MPa). However, there was no significant difference in the strength between the control and carbide bur treated specimens. Similarly, the fatigue strength of the diamond bur treated specimens was significantly lower (p ≤ 0.0001) than that of the control for both cutting directions. Cutting in the perpendicular direction resulted in nearly 60% reduction to the endurance limit (from 44 to 19 MPa). Based on the results, diamond bur cutting of cavity preparations causes a reduction in the fatigue strength of dentin, regardless of the cutting direction. To maintain the durability of dentin, cavity preparations introduced using diamond burs must be performed with appropriate cutting direction and followed by a finishing pass. © 2014 Wiley Periodicals, Inc.

Construction and in vitro test of a new electrode for dentin resistance measurement.

PubMed

Stein, Steffen; Gente, Michael

2013-10-01

It is necessary to reduce the tooth substance before treating a tooth with a dental crown. The preparation often requires reduction of the dentin. This results in a dentin wound and a thinner substance over the pulp, increases the risk of inflammation, and could result in necrosis of the pulp. To give the dentist information about the amount of dentin over the pulp during preparation, the Prepometer was developed. The function of this device is based on the measurement of the electric resistance of the tooth substance. The measuring behavior of the first-generation Prepometer is characterized by smaller values of electric resistance before reaching full contact of the measuring head to the dentin surface and the actual value RT. This measuring behavior can mislead inexperienced therapists with inaccurate values that suggest thinner dentin than the reality. In this study, a new electrode based on the technology of active guard drive was constructed to overcome this issue. The results show that improvement in the measuring behavior of the new electrode could be achieved, eliminating the earlier disadvantage of the Prepometer.

Dicalcium phosphate (CaHPO4·2H2O) precipitation through ortho- or meta-phosphoric acid-etching: effects on the durability and nanoleakage/ultra-morphology of resin-dentine interfaces.

PubMed

Feitosa, Victor Pinheiro; Bazzocchi, Maria Giulia; Putignano, Angelo; Orsini, Giovanna; Luzi, Arlinda Luzi; Sinhoreti, Mário Alexandre Coelho; Watson, Timothy F; Sauro, Salvatore

2013-11-01

To compare the effects of two etching procedures using meta-phosphoric (MPA) or ortho-phosphoric acid (OPA) on dentine demineralisation, resin-dentine bonds durability and interface nanoleakage/ultra-morphology. Middle-dentine specimens were etched using 37% OPA (15s) or 40% MPA (60s) and submitted to infrared spectroscopy (FTIR) or ultra-morphology dye-assisted (calcium-staining) confocal microscopy (Ca-CLSM). A three-step etch-and-rinse adhesive was formulated, applied onto dentine and light-cured for 30s before composite build-up. After 24h, the dentine-bonded specimens were cut into 1mm(2) beams; half were immediately submitted to microtensile bond strength (μTBS) and half stored in DW for six months. The μTBS results were analysed with repeated-measures ANOVA and Tukey's test (p<0.05). Further teeth were bonded and prepared for interface nanoleakage/ultra-morphology confocal evaluation. FTIR and Ca-CLSM analyses showed dicalcium phosphate dihydrate (Brushite) precipitation in MPA-etched dentine and on the bottom (front of demineralisation) of the OPA-etched dentine. Statistical analysis showed similar μTBS for both etching procedures after 24h. The μTBS of specimens in OPA-group dropped significantly (p<0.05) after six month; the specimens in the MPA group showed no statistically difference (p>0.05). CLSM depicted no evident sign of nanoleakage within the resin-dentine interface of the MPA-treated specimens, while the specimens in OPA-group presented intense nanoleakage and interface degradation. The use of MPA (60s) as an alternative dentine conditioning agent in etch-and-rinse bonding procedures may be a suitable strategy to create more durable resin-dentine bonds. Copyright © 2013 Elsevier Ltd. All rights reserved.

Inhibition of endogenous human dentin MMPs by Gluma

PubMed Central

Sabatini, Camila; Scheffel, Débora L.S.; Scheffel, Régis H.; Agee, Kelli A.; Rouch, Katelyn; Takahashi, Masahiro; Breschi, Lorenzo; Mazzoni, Annalisa; Tjäderhane, Leo; Tay, Franklin R.; Pashley, David H.

2014-01-01

Objective The objective of this study was to determine if Gluma dentin desensitizer (5.0% glutaraldehyde and 35% HEMA in water) can inhibit the endogenous MMPs of dentin matrices in 60 sec. and to evaluate its effect on dentin matrix stiffness and dry mass weight. Methods Dentin beams of 2×1×6 mm were obtained from extracted human third molars coronal dentin. To measure the influence of Gluma treatment time on total MMP activity of dentin, beams were dipped in 37% phosphoric acid (PA) for 15 sec. and rinsed in water. The acid-etched beams were then dipped in Gluma for 5, 15, 30 or 60 sec., rinsed in water and incubated into SensoLyte generic MMP substrate (AnaSpec, Inc.) for 60 min. Controls were dipped in water for 60 sec. Additional beams of 1×1×6 mm were completely demineralized in 37% PA for 18 h, rinsed and used to evaluate changes on the dry weight and modulus of elasticity (E) after 60 sec. of Gluma treatment followed by incubation in simulated body fluid buffer for zero, one or four weeks. E was measured by 3-pt flexure. Results Gluma treatment inhibited total MMP activity of acid-etched dentin by 44, 50, 84, 86 % after 5, 15, 30 or 60 sec. of exposure, respectively. All completely demineralized dentin beams lost stiffness after one and four weeks, with no significant differences between the control and Gluma-treated dentin. Gluma treatment for 60 sec. yielded significantly less dry mass loss than the control after four weeks. Significance The use of Gluma may contribute to the preservation of adhesive interfaces by its cross-linking and inhibitory properties of endogenous dentin MMPs. PMID:24846803

Long-term dentin remineralization by poly(amido amine) and rechargeable calcium phosphate nanocomposite after fluid challenges.

PubMed

Liang, Kunneng; Xiao, Shimeng; Wu, Junling; Li, Jiyao; Weir, Michael D; Cheng, Lei; Reynolds, Mark A; Zhou, Xuedong; Xu, Hockin H K

2018-04-01

Previous studies investigated short-term dentin remineralization; studies on long-term dentin remineralization after fluid challenges mimicking fluids in oral environment are lacking. The objective of this study was to develop a long-term remineralization method to via poly(amido amine) (PAMAM) and rechargeable composite containing nanoparticles of amorphous calcium phosphate (NACP) after fluid challenges for the first time. NACP composite was immersed at pH 4 to exhaust its calcium (Ca) and phosphate (P) ions, and then recharged with Ca and P ions, to test the remineralization of the exhausted and recharged NACP composite. Dentin was acid-etched with 37% phosphoric acid. Four groups were prepared: (1) dentin control, (2) dentin with PAMAM, (3) dentin with the recharged NACP composite, and (4) dentin with PAMAM plus recharged NACP composite. PAMAM-coated dentin was immersed in phosphate-buffered saline with shaking for 72 days, because there is fluid flow in the mouth which could potentially detach the PAMAM from dentin. Specimens were treated with a cyclic artificial saliva/lactic acid regimen for 35 days. After 72days of immersion plus shaking, the PAMAM still successfully fulfilled its mineralization nucleation. The recharged NACP composite still provided acid-neutralization and ion re-release, which did not decrease with increasing the number of recharge cycles. The immersed-PAMAM plus NACP achieved complete dentin remineralization and restored the hardness to that of healthy dentin. In conclusion, superior long-term remineralization of the PAMAM plus NACP method was demonstrated for the first time. The immersed-PAMAM plus recharged NACP completely remineralized the pre-demineralized dentin, even after prolonged fluid-challenge similar to that in oral environment. The novel PAMAM plus NACP composite method is promising to provide long-term tooth protection and caries inhibition. Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Short term serum pharmacokinetics of diammine silver fluoride after oral application.

PubMed

Vasquez, Elsa; Zegarra, Graciela; Chirinos, Edgar; Castillo, Jorge L; Taves, Donald R; Watson, Gene E; Dills, Russell; Mancl, Lloyd L; Milgrom, Peter

2012-12-31

There is growing interest in the use of diammine silver fluoride (DSF) as a topical agent to treat dentin hypersensitivity and dental caries as gauged by increasing published research from many parts of the world. While DSF has been available in various formulations for many years, most of its pharmacokinetic aspects within the therapeutic concentration range have never been fully characterized. This preliminary study determined the applied doses (3 teeth treated), maximum serum concentrations, and time to maximum serum concentration for fluoride and silver in 6 adults over 4 h. Fluoride was determined using the indirect diffusion method with a fluoride selective electrode, and silver was determined using inductively coupled plasma-mass spectrometry. The mean amount of DSF solution applied to the 3 teeth was 7.57 mg (6.04 μL). Over the 4 hour observation period, the mean maximum serum concentrations were 1.86 μmol/L for fluoride and 206 nmol/L for silver. These maximums were reached 3.0 h and 2.5 h for fluoride and silver, respectively. Fluoride exposure was below the U.S. Environmental Protection Agency (EPA) oral reference dose. Silver exposure exceeded the EPA oral reference dose for cumulative daily exposure over a lifetime, but for occasional use was well below concentrations associated with toxicity. This preliminary study suggests that serum concentrations of fluoride and silver after topical application of DSF should pose little toxicity risk when used in adults. NCT01664871.

Short term serum pharmacokinetics of diammine silver fluoride after oral application

PubMed Central

2012-01-01

Background There is growing interest in the use of diammine silver fluoride (DSF) as a topical agent to treat dentin hypersensitivity and dental caries as gauged by increasing published research from many parts of the world. While DSF has been available in various formulations for many years, most of its pharmacokinetic aspects within the therapeutic concentration range have never been fully characterized. Methods This preliminary study determined the applied doses (3 teeth treated), maximum serum concentrations, and time to maximum serum concentration for fluoride and silver in 6 adults over 4 h. Fluoride was determined using the indirect diffusion method with a fluoride selective electrode, and silver was determined using inductively coupled plasma-mass spectrometry. The mean amount of DSF solution applied to the 3 teeth was 7.57 mg (6.04 μL). Results Over the 4 hour observation period, the mean maximum serum concentrations were 1.86 μmol/L for fluoride and 206 nmol/L for silver. These maximums were reached 3.0 h and 2.5 h for fluoride and silver, respectively. Conclusions Fluoride exposure was below the U.S. Environmental Protection Agency (EPA) oral reference dose. Silver exposure exceeded the EPA oral reference dose for cumulative daily exposure over a lifetime, but for occasional use was well below concentrations associated with toxicity. This preliminary study suggests that serum concentrations of fluoride and silver after topical application of DSF should pose little toxicity risk when used in adults. Clinical trials registration NCT01664871. PMID:23272643

Retinoids activate the irritant receptor TRPV1 and produce sensory hypersensitivity

PubMed Central

Yin, Shijin; Luo, Jialie; Qian, Aihua; Du, Junhui; Yang, Qing; Zhou, Shentai; Yu, Weihua; Du, Guangwei; Clark, Richard B.; Walters, Edgar T.; Carlton, Susan M.; Hu, Hongzhen

2013-01-01

Retinoids are structurally related derivatives of vitamin A and are required for normal vision as well as cell proliferation and differentiation. Clinically, retinoids are effective in treating many skin disorders and cancers. Application of retinoids evokes substantial irritating side effects, including pain and inflammation; however, the precise mechanisms accounting for the sensory hypersensitivity are not understood. Here we show that both naturally occurring and synthetic retinoids activate recombinant or native transient receptor potential channel vanilloid subtype 1 (TRPV1), an irritant receptor for capsaicin, the pungent ingredient of chili peppers. In vivo, retinoids produced pain-related behaviors that were either eliminated or significantly reduced by genetic or pharmacological inhibition of TRPV1 function. These findings identify TRPV1 as an ionotropic receptor for retinoids and provide cellular and molecular insights into retinoid-evoked hypersensitivity. These findings also suggest that selective TRPV1 antagonists are potential therapeutic drugs for treating retinoid-induced sensory hypersensitivity. PMID:23925292

Insulin-like growth factor 1 can promote the osteogenic differentiation and osteogenesis of stem cells from apical papilla.

PubMed

Wang, Sainan; Mu, Jinquan; Fan, Zhipeng; Yu, Yan; Yan, Ming; Lei, Gang; Tang, Chunbo; Wang, Zilu; Zheng, Yangyu; Yu, Jinhua; Zhang, Guangdong

2012-05-01

Insulin-like growth factor 1 (IGF-1) plays an important role in the regulation of tooth root development, and stem cells from apical papilla (SCAPs) are responsible for the formation of root pulp and dentin. To date, it remains unclear whether IGF-1 can regulate the function of SCAPs. In this study, SCAPs were isolated and purified from human immature root apex, and stimulated by 100 ng/mL exogenous IGF-1. The effects of IGF-1 on the proliferation and differentiation of SCAPs were subsequently investigated. IGF-1 treated SCAPs presented the morphological and ultrastructural changes. Cell proliferation, alkaline phosphatase (ALP) activity and mineralization capacity of SCAPs were increased by IGF-1. Western blot and quantitative RT-PCR analyses further demonstrated that the expression of osteogenic-related proteins and genes (e.g., alkaline phosphatase, runt-related transcription factor 2, osterix, and osteocalcin) was significantly up-regulated in IGF-1 treated SCAPs, whereas the expression of odontoblast-specific markers (e.g., dentin sialoprotein and dentin sialophosphoprotein) was down-regulated by IGF-1. In vivo results revealed that IGF-1 treated SCAPs mostly gave birth to bone-like tissues while untreated SCAPs mainly generated dentin-pulp complex-like structures after transplantation. The present study revealed that IGF-1 can promote the osteogenic differentiation and osteogenesis capacity of SCAPs, but weaken their odontogenic differentiation and dentinogenesis capability, indicating that IGF-1 treated SCAPs can be used as a potential candidate for bone tissue engineering. Copyright © 2011 Elsevier B.V. All rights reserved.

Morphological effects of MMPs inhibitors on the dentin bonding

PubMed Central

Li, He; Li, Tianbo; Li, Xiuying; Zhang, Zhimin; Li, Penglian; Li, Zhenling

2015-01-01

Matrix metalloproteinases (MMPs) have been studied extensively, and MMP inhibitors have been used as dental pretreatment agents prior to dentin bonding because they reduce collagen fiber degradation and improve bonding strength. However, morphologic characteristics of the collagen network after etching and of the post-adhesive dentin hybrid layers (DHL) after MMP inhibitors pretreatment have not been evaluated. Thus, we investigated demineralized dentin pretreated with chlorhexidine (CHX) and minocycline (MI) in an etch- and -rinse adhesive system with field emission scanning electron microscopy (FESEM) and immuno-gold labeling markers to observe the collagen network and DHL. FESEM revealed after CHX and MI, a demineralized dentin surface and improved collagen network formation, reduced collagen degradation, and distinct gold-labeling signals. Applying adhesive after either MMP inhibitor created a better dentin interface as evidenced by immuno-gold staining, better adhesive penetration, and higher DHL quality. With microtensile bond strength tests (µTBS) we estimated bonding strength using µTBS data. Immediate µTBS was enhanced with MMP inhibitor application to the bonding surface, and the CHX group was significantly different than non-treated etched surfaces, but no significant change was detected in the MI group. Surface micromorphology of the fractured dentin resin restoration showed that the CHX group had a better resin and dentin tube combination. Both MMP inhibitors created uniform resin coverage. Thus, morphologic results and µTBS data suggest that CHX and MI can inhibit MMP activity, improve immediate bonding strength, and enhance dentin bonding stability with an etch- and -rinse adhesive system. PMID:26379873

Effect of an acid diet allied to sonic toothbrushing on root dentin permeability: an in vitro study.

PubMed

Pinto, Shelon Cristina Souza; Batitucci, Roberta Grasseli; Pinheiro, Michele Carolina; Zandim, Daniela Leal; Spin-Neto, Rubens; Sampaio, José Eduardo Cezar

2010-01-01

This study quantified alterations in root dentin permeability after exposure to different acid beverages. Twenty-five third molars were sectioned below the cementoenamel junction, the root segment was collected, and the pulp tissue was removed. The root segments were connected to a hydraulic pressure apparatus to measure the permeability of root dentin after the following sequential steps, with 5 specimens in each: 1) phosphoric acid etching for 30 s (maximum permeability), 2) root planning to create new smear layer, 3) exposure to different acid substances for 5 min (orange, cola drink, vinegar, white wine, lemon juice), 4) toothbrushing with sonic toothbrush for 3 min, 5) toothbrushing with sonic toothbrush plus dentifrice for 3 min. Considering step I as 100%, the data were converted into percentage and each specimen was its own control. Data were analyzed statistically by Kruskal-Wallis and Dunn's post test at 5% significance level. All acidic substances increased dentin permeability significantly after scraping (p< 0.05). Toothbrushing after exposure to acid substances decreased dentin permeability and the association with dentifrice accentuated the decrease (p< 0.05), except for the specimens treated with cola drink. Thus, it may be concluded that all tested acid fruit juices increased dentin permeability, and toothbrushing with or without dentifrice can decrease root dentin permeability after dentin exposure to acid diet.

Dissociation between the relief of skeletal pain behaviors and skin hypersensitivity in a model of bone cancer pain.

PubMed

Guedon, Jean-Marc G; Longo, Geraldine; Majuta, Lisa A; Thomspon, Michelle L; Fealk, Michelle N; Mantyh, Patrick W

2016-06-01

Recent studies have suggested that in humans and animals with significant skeletal pain, changes in the mechanical hypersensitivity of the skin can be detected. However, whether measuring changes in skin hypersensitivity can be a reliable surrogate for measuring skeletal pain itself remains unclear. To explore this question, we generated skeletal pain by injecting and confining GFP-transfected NCTC 2472 osteosarcoma cells unilaterally to the femur of C3H male mice. Beginning at day 7 post-tumor injection, animals were administered vehicle, an antibody to the P2X3 receptor (anti-P2X3) or anti-NGF antibody. Pain and analgesic efficacy were then measured on days 21, 28, and 35 post-tumor injection using a battery of skeletal pain-related behaviors and von Frey assessment of mechanical hypersensitivity on the plantar surface of the hind paw. Animals with bone cancer pain treated with anti-P2X3 showed a reduction in skin hypersensitivity but no attenuation of skeletal pain behaviors, whereas animals with bone cancer pain treated with anti-NGF showed a reduction in both skin hypersensitivity and skeletal pain behaviors. These results suggest that although bone cancer can induce significant skeletal pain-related behaviors and hypersensitivity of the skin, relief of hypersensitivity of the skin is not always accompanied by attenuation of skeletal pain. Understanding the relationship between skeletal and skin pain may provide insight into how pain is processed and integrated and help define the preclinical measures of skeletal pain that are predictive end points for clinical trials.

Dissociation between the relief of skeletal pain behaviors and skin hypersensitivity in a model of bone cancer pain

PubMed Central

Guedon, Jean-Marc G.; Longo, Geraldine; Majuta, Lisa A.; Thomspon, Michelle L.; Fealk, Michelle N.; Mantyh, Patrick W.

2016-01-01

Recent studies have suggested that in humans and animals with significant skeletal pain, changes in the mechanical hypersensitivity of the skin can be detected. However, whether measuring changes in skin hypersensitivity can be a reliable surrogate for measuring skeletal pain itself remains unclear. To explore this question we generated skeletal pain by injecting and confining GFP-transfected NCTC 2472 osteosarcoma cells unilaterally to the femur of C3H male mice. Beginning at day 7 post-tumor injection, animals were administered vehicle, an antibody to the P2X3 receptor (anti-P2X3) or anti-NGF antibody. Pain and analgesic efficacy was then measured on days 21, 28 and 35 post-tumor injection using a battery of skeletal pain-related behaviors and von Frey assessment of mechanical hypersensitivity on the plantar surface of the hindpaw. Animals with bone cancer pain treated with anti-P2X3 showed a reduction in skin hypersensitivity but no attenuation of skeletal pain behaviors. Whereas animals with bone cancer pain treated with anti-NGF showed a reduction in both skin hypersensitivity and skeletal pain behaviors. These results suggest that while bone cancer can induce significant skeletal pain-related behaviors and hypersensitivity of the skin, relief of hypersensitivity of the skin is not always accompanied by attenuation of skeletal pain. Understanding the relationship between skeletal and skin pain may provide insight into how pain is processed and integrated and help define the preclinical measures of skeletal pain that are predictive endpoints for clinical trials. PMID:27186713

Investigation of biomineralization by Raman spectroscopy

NASA Astrophysics Data System (ADS)

Fatscher, Robert William

Biomineralization is a process in which living organism grow composite materials consisting of inorganic and organic materials. This produces a composite material consisting of both inorganic and organic components, with superior mechanical properties. In the human body bone and dentin are both examples of biominerals. In this research Raman spectroscopy was used to characterize dentin from mice and human teeth, to determine composition. In the mouse tooth samples areas of irregular dentin were found, along the inside of the tooth, to be in the process of mineralization. By analyzing the samples along these areas we were able to determine the composition of dentin and track how it changed in these area. By analysis of the mineral to matrix ratio the areas of irregular dentin were determined to have less mineral present. Observations of other organic components and collagen in increased concentrations in this area suggested these area were in the process of biomineralization. The understanding of the structure of dentin and its biomineralization process is of crucial importance when trying reproduce dentin. Scientists and engineers are able to produce dentin minerals in vitro by culturing various dental stem cells. The ability to create dentin mineral from cells could lead to methods of repairing dentin in patients, or even lead to the creation of a completely engineered tooth. While dentin-like materials can be produced in a laboratory environment, analysis and comparison of the composition of these materials must be performed to ensure the mineral produced is consistent with dentin. Mineralized nodules from six different dental stem cell lines were cultured to produce a mineralized deposit. Utilizing Raman spectroscopy, we were able to determine cell source dependent differences in a variety of dental stem cells, and compare the mineral produced to native dentin. Orthopedic implants are implants used to replace damaged bone, examples include knee, hip and dental implants. These implants are designed to osteointegrate with the native healthy tissues in order to create a functionally stable and structural interface. Biomaterials such as hydroxyapatite and titania are known to increase the rate of bone regeneration in vivo.1 By accelerating the early response of bone forming cells to these implants, better fixation is achieved between the implant and the bone, shortening recovery times and increasing the viability of these implants. In the last part of this research an investigation of osteoblasts cultured at 14 days on five different heat-treated titania substrates was investigated by Raman spectroscopy, in order to observe the initial cellular response to the titania substrates. The heat-treatment of titania changes the amount of oxygen on it's surface which in turn effects the surface energy. A change in the surface energy of a material will affect the cellular response, by culturing cells on various heat-treated titania substrates a relationship between the surface energy and cellular response can be investigated. A faster cellular response would lead to an increased rate of bone regeneration shortening healing times and allowing for better fixation of the implant.

Effect of Minocycline on the Durability of Dentin Bonding Produced with Etch-and-Rinse Adhesives.

PubMed

Loguercio, A D; Stanislawczuk, R; Malaquias, P; Gutierrez, M F; Bauer, J; Reis, A

2016-01-01

To evaluate the effect of minocycline and chlorhexidine pretreatment of acid-etched dentin on the longevity of resin-dentin bond strength (μTBS) and nanoleakage of two-step etch-and-rinse adhesives. Before application of Prime & Bond NT and Adper Single Bond 2 in occlusal dentin, the dentin surfaces were treated with 37% phosphoric acid, rinsed, air-dried, and rewetted with water (control group), 2% minocycline, or 2% chlorexidine digluconate. Composite buildups were constructed incrementally, and specimens were longitudinally sectioned to obtain bonded sticks (0.8 mm 2 ) to be tested in tension (0.5 mm/min) immediately or after 24 months of water storage. For nanoleakage, two specimens of each tooth/period were immersed in the silver nitrate solution, photo-developed, and polished with SiC paper for analysis under energy-dispersive X-ray spectroscopy/scanning electron microscopy. Reductions of the μTBS and increases in the nanoleakage were observed for both adhesives when the rewetting procedure was performed with water. Stable bonds were observed for the 2% minocycline and 2% chlorexidine digluconate groups after 24 months. The use of 2% minocycline as pretreatment of acid-etched dentin is one alternative to retard the degradation of resin-dentin interfaces over a 24-month period as well as 2% chlorexidine digluconate.

Comparative evaluation of fracture resistance under static and fatigue loading of endodontically treated teeth restored with carbon fiber posts, glass fiber posts, and an experimental dentin post system: an in vitro study.

PubMed

Ambica, Khetarpal; Mahendran, Kavitha; Talwar, Sangeeta; Verma, Mahesh; Padmini, Govindaswamy; Periasamy, Ravishankar

2013-01-01

This investigation sought to compare the fracture resistance under static and fatigue loading of endodontically treated teeth restored with fiber-reinforced composite posts and experimental dentin posts milled from human root dentin by using computer-aided design/computer-aided manufacturing. Seventy maxillary central incisors were obturated and divided into 4 groups: control group without any post (n = 10), carbon fiber post group (n = 20), glass fiber post group (n = 20), and dentin post group (n = 20). Control group teeth were prepared to a height of 5 mm. In all other teeth, post space was prepared; a post was cemented, and a core build-up was provided. Half the samples from each group were statistically loaded until failure, and the remaining half were subjected to cyclic loading, followed by monostatic load until fracture. One-way analysis of variance and Bonferroni multiple comparisons revealed a significant difference among test groups. The control group demonstrated highest fracture resistance (935.03 ± 33.53 N), followed by the dentin post group (793.12 ± 33.69 N), glass fiber post group (603.44 ± 46.67 N), and carbon fiber post group (497.19 ± 19.27 N) under static loading. These values reduced to 786.69 ± 29.64 N, 646.34 ± 26.56 N, 470 ± 36.34 N, and 379.71 ± 13.95 N, respectively, after cyclic loading. Results suggest that human dentin can serve as post material under static and fatigue loading. Although at an early stage in research, the use of dentin posts in root-filled teeth looks promising. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Sodium Hypochlorite Irrigation and Its Effect on Bond Strength to Dentin

PubMed Central

Abuhaimed, Tariq S.

2017-01-01

Effective shaping and cleaning of root canals are essential for the success of endodontic treatment. Due to the complex anatomy of root canal spaces, the use of various instrumentation techniques alone is not effective in producing bacteria-free root canal spaces. Irrigation, disinfectants, rinses, and intervisit medications are used in conjunction with the mechanical instrumentation to ensure the success of endodontic treatment. Sodium hypochlorite (NaOCl), a halogenated compound, is routinely used to irrigate the root canal during endodontic treatments. NaOCl has been known for its antibacterial action, proteolytic and dissolution capacity, and debridement properties. NaOCl, however, can alter the composition of dentin and hence its interaction with the adhesive resins used to bond the restorative materials to treated dentin. This review therefore covers in depth the action of NaOCl on dentin-adhesive resin bond strength including both enhancement and reduction, then mechanisms proposed for such action, and finally how the adverse action of NaOCl on dentin can be reversed. PMID:28904947

Sodium Hypochlorite Irrigation and Its Effect on Bond Strength to Dentin.

PubMed

Abuhaimed, Tariq S; Abou Neel, Ensanya A

2017-01-01

Effective shaping and cleaning of root canals are essential for the success of endodontic treatment. Due to the complex anatomy of root canal spaces, the use of various instrumentation techniques alone is not effective in producing bacteria-free root canal spaces. Irrigation, disinfectants, rinses, and intervisit medications are used in conjunction with the mechanical instrumentation to ensure the success of endodontic treatment. Sodium hypochlorite (NaOCl), a halogenated compound, is routinely used to irrigate the root canal during endodontic treatments. NaOCl has been known for its antibacterial action, proteolytic and dissolution capacity, and debridement properties. NaOCl, however, can alter the composition of dentin and hence its interaction with the adhesive resins used to bond the restorative materials to treated dentin. This review therefore covers in depth the action of NaOCl on dentin-adhesive resin bond strength including both enhancement and reduction, then mechanisms proposed for such action, and finally how the adverse action of NaOCl on dentin can be reversed.

Effect of time on tensile bond strength of resin cement bonded to dentine and low-viscosity composite.

PubMed

Duarte, Rosângela Marques; de Goes, Mario Fernando; Montes, Marcos Antonio Japiassú Resende

2006-01-01

The purpose of this study was to evaluate the tensile bond strength (TBS) of Panavia F resin cement (PF) applied on dentine pre-treated with ED Primer (ED) and Clearfil Liner Bond 2V (CLB) coated with a layer of low-viscosity composite Protect Liner F (PLF) at 10 min, 24 h and 12 months after curing. The labial surfaces of 60 bovine lower incisors were ground to obtain a flat dentine surface, allowing a demarcation of a 4.0 mm-diameter area with adhesive tape. The teeth were randomly divided in six groups; ED was applied in groups A I, A II and A III and CLB was applied, followed by PLF, in groups B I, B II and B III. A resin composite rod with a wire loop was luted directly to the prepared surface of each group with PF. The specimens of groups A I and B I were submitted to TBS test after 10 min. Groups A II and B II were submitted to TBS test after 24 h storage and groups A III and B III were submitted to TBS test after 12 months storage. Each specimen was inspected by SEM and classified according to the failure mode. Additionally, two representative specimens of each failure mode were sectioned for a composite/dentine interface SEM evaluation. No significant statistical differences were observed among the groups at 10 min and 24 h. Groups A III and B III presented the lowest TBS values (p<0.05) after 12 months storage. PF on resin-coated dentin (PLF) showed the highest TBS values and was statistically different to PF on dentine for all the groups. The fracture pattern was generally cohesive on the adhesive/hybrid layer for groups A I, A II and A III and cohesive on composite resin for B I, B II and B III. The use of a less hydrophilic self-etching system to pre-treat dentine, coating with a low-viscosity composite layer prior luting with resin cement, may provide a protection of the hybridised complex, allowing a dentine seal during the 12 months storage period.

The use of acetone to enhance the infiltration of HA nanoparticles into a demineralized dentin collagen matrix.

PubMed

Besinis, Alexandros; van Noort, Richard; Martin, Nicolas

2016-03-01

This study investigates the role of acetone, as a carrier for nano-hydroxyapatite (nano-HA) in solution, to enhance the infiltration of fully demineralized dentin with HA nanoparticles (NPs). Dentin specimens were fully demineralized and subsequently infiltrated with two types of water-based nano-HA solutions (one containing acetone and one without). Characterization of the dentin surfaces and nano-HA particles was performed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The surface wettability and infiltration capacity of the nano-HA solutions were quantified by means of contact angle measurements and energy dispersive X-ray spectroscopy (EDS), respectively. Contact angle measurements were taken at baseline and repeated at regular intervals to assess the effect of acetone. The P and Ca levels of infiltrated dentin specimens were measured and compared to sound dentin and non-infiltrated controls. The presence of acetone resulted in an eight-fold decrease in the contact angles of the nano-HA solutions recorded on the surface of demineralized dentin compared to nano-HA solutions without acetone (one-way ANOVA, p<0.05). Perfect wetting of the demineralized dentin surface was achieved 5min after the application of the nano-HA solution containing acetone. Infiltration of demineralized dentin with the nano-HA solution containing acetone restored the lost mineral content by 50%, whereas the mean mineralization values for P and Ca in dentin treated with the acetone-free nano-HA solution were less than 6%. Acetone was shown to act as a vehicle to enhance the capacity to infiltrate demineralized dentin with HA NPs. The successful infiltration of dentin collagen with HA NPs provides a suitable scaffold, whereby the infiltrated HA NPs have the potential to act as seeds that may initiate heterogenous mineral growth when exposed to an appropriate mineral-rich environment. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Biomechanical studies on the effect of iatrogenic dentin removal on vertical root fractures

PubMed Central

Ossareh, A.; Rosentritt, M.; Kishen, A.

2018-01-01

Introduction: The aim of this study was to understand the mechanism by which iatrogenic root dentin removal influences radicular stress distribution and subsequently affects the resistance to vertical root fractures (VRF) in endodontically treated teeth. Materials and Methods: The experiments were conducted in two phases. Phase 1: freshly extracted premolar teeth maintained in phosphate-buffered saline were instrumented to simulate three different degrees of dentin removal, designated as low, medium, and extreme groups. Micro-Ct analyzes were performed to quantitatively determine: (a) the amount of dentin removed, (b) the remaining dentin volume, and (c) the moment of inertia of root dentin. The specimens were then subjected to thermomechanical cycling and continuous loading to determine (a) the mechanical load to fracture and (b) dentin microcracking (fractography) using scanning electron microscopy. Phase 2: Finite element analysis was used to evaluate the influence of dentin removal on the stress distribution pattern in root dentin. The data obtained were analyzed using one-way ANOVA and Tukey's post hoc test (P < 0.05). Results: Phase 1: A significantly greater volume of dentin was removed from teeth in extreme group when compared to low group (P < 0.01). The mechanical analysis showed that the load to fracture was significantly lower in teeth from extreme group (P < 0.05). A linear relationship was observed between the moment of inertia and load to fracture in all experimental groups (R2 = 0.52). Fractography showed that most microcracks were initiated from the root canal walls in extreme group. Phase 2: The numerical analysis showed that the radicular stress distribution increased apically and buccolingually with greater degree of root canal dentin removal. Conclusions: The combined experimental/numerical analyses highlighted the influence of remaining root dentin volume on the radicular bending resistance, stress distribution pattern, and subsequent propensity to VRF. PMID:29899632

Proanthocyanidins’ efficacy in stabilizing dentin collagen against enzymatic degradation: MALDI-TOF and FTIR analyses

PubMed Central

Liu, Yi; Wang, Yong

2013-01-01

Objectives To investigate grape seed extract proanthocyanidins’ (PA) capability in improving dentin collagen’s sustainability in an enzymatic environment, given that the size and shape of the collagen samples, and the manner to apply PA are both clinically relevant. Methods Human dentin was sectioned into 6-μm-thick films. After demineralization in 35 wt% phosphoric acid for 15 s, the films were subject to 30 s of treatment at PA concentrations of 0% (control), 0.5%, 1%, 2%, 3.75%, 7.5% and 15% (w/w), respectively. The films were then digested in 0.1 wt% collagenase for 1 h and 24 h. The amount of degraded collagen in the liquid digests was determined by MALDI-TOF mass spectroscopy. The trend of PA’s incorporation into dentin collagen was analyzed by ATR-FTIR. Results The control exhibited complete digestion in 1 h. In contrast, collagen treated with 0.5% and 1% PA afforded 13.84 ± 4.69% and an undetectable level of degradation, respectively in the first 1 h of digestion, and additional 17.48 ± 4.38% and 4.50 ± 1.68%, respectively in the following 23 h. Collagen treated with ≥2 wt% PA was not significantly digested regardless of digestion time. FTIR spectroscopy revealed that PA incorporation was saturated at ≥2 wt% PA. Conclusion Thirty seconds of PA treatment at 2 wt% and above could provide optimal protection for dentin collagen against collagenase digestion. Clinical significance This study demonstrated PA’s extraordinary efficiency in stabilizing demineralized dentin collagen when it is applied in a clinical relevant manner, and identified the optimal conditions for its utilization. PMID:23578472

Effectiveness of plant-derived proanthocyanidins on demineralization on enamel and dentin under artificial cariogenic challenge

PubMed Central

da SILVA, Ana Paula Pereira; GONÇALVES, Rafael Simões; BORGES, Ana Flávia Sanches; BEDRAN-RUSSO, Ana Karina; SHINOHARA, Mirela Sanae

2015-01-01

Dental caries is considered a disease of high prevalence and a constant problem in public health. Proanthocyanidins (PAs) are substances that have been the target of recent studies aiming to control or treat caries. Objective The aim of this in vitro study was to evaluate the efficacy of a treatment with grape seed extract, under cariogenic challenge, to minimize or even prevent the onset of caries in the enamel and dentin. Material and Methods Blocks of enamel and dentin (6.0x6.0 mm) were obtained from bovine central incisors, polished, and selected by analysis of surface microhardness (SH). The blocks were randomly divided into 3 groups (n=15), according to the following treatments: GC (control), GSE (grape seed extract), GF (fluoride – 1,000 ppm). The blocks were subjected to 6 daily pH cycles for 8 days. Within the daily cycling, the specimens were stored in buffered solution. The blocks were then analyzed for perpendicular and surface hardness and polarized light microscopy. Results The means were subjected to statistical analysis using the ANOVA and Fisher’s PLSD tests (p<0.05). For enamel SH, GF showed the highest hardness values. In the dentin, GF was also the one that showed higher hardness values, followed by GSE. Regarding the cross-sectional hardness values, all groups behaved similarly in both the enamel and dentin. The samples that were treated with GSE and fluoride (GF) showed statistically higher values than the control. Conclusion Based on the data obtained in this in vitro study, it is suggested that grape seed extract inhibits demineralization of artificial carious lesions in both the enamel and dentin, but in a different scale in each structure and in a smaller scale when compared to fluoride. PMID:26221925

Antibacterial Properties Associated with Chitosan Nanoparticle Treatment on Root Dentin and 2 Types of Endodontic Sealers.

PubMed

Del Carpio-Perochena, Aldo; Kishen, Anil; Shrestha, Annie; Bramante, Clovis Monteiro

2015-08-01

The aim of this study was to evaluate the efficacy of carboxymethyl chitosan (CMCS) and chitosan nanoparticles (CNps) to inactivate bacteria and prevent biofilm formation at sealer-dentin interfaces. The study was divided into 3 stages: first stage, the experiment was conducted to analyze the antibacterial properties of CMCS in different formulations against biofilms; second stage, direct-contact and membrane-restricted methods were used to evaluate the antibacterial properties of an epoxy resin (ThermaSeal Plus; Dentsply Tulsa Dental, Tulsa, OK) and calcium silicate (MTA Fillapex; Angelus SA, Londrina, PR, Brazil) based-sealers with or without CNps; and third stage, biofilm formation at the sealer dentin interfaces of root dentin treated with CMCS and filled with gutta-percha and CNp incorporated sealer were analyzed after 1- and 4-week aging periods. The samples were treated and filled as follows: (1) distilled water: unaltered sealer (control group), (2) CMCS: sealer+CNps (CMCS group), and (3) CMCS/rose bengal: sealer+CNps (CMCS/RB group). Enterococcus faecalis was used to infect all the samples. Microbiological and microscopic analyses were used to assess the antibacterial characteristics. CMCS-based treatments effectively killed bacteria adherent on root dentin (P < .05). The addition of CNps to ThermaSeal enhanced its antibacterial ability by direct-contact and membrane-restricted tests (P < .05). The CNp incorporation significantly increased the antibacterial efficacy of root canal sealers even after a 4-week aging time (P < .05). This study highlighted the ability of CMCS to disinfect root canal dentin and inhibit bacterial adhesion. CNps in root canal sealers are capable of maintaining their antibacterial activity even after prolonged aging. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Characterization of dental pulp defect and repair in a canine model.

PubMed

Yildirim, Sibel; Can, Alp; Arican, Mustafa; Embree, Mildred C; Mao, Jeremy J

2011-12-01

To explore a relationship between the size of pulp chamber perforation and reparative dentin formation in a canine model. Pulp defects were created in the pulp chambers of maxillary and mandibular premolars (N = 64) in 17 healthy mongrel dogs in three different sizes (diameter/depth: 1/1, 2/1, and 2/2 mm3) with sterile round burs under general anesthesia. The perforations were immediately capped with hard-setting calcium hydroxide (CH) in the control group or sealed with Teflon membrane (TM) in the experimental group, followed by restoration with reinforced zinc oxide eugenol cement in vivo. Seven and 30 days after pulp chamber perforation and restoration all treated and control premolars were extracted and prepared for histomorphometric and statistical analyses. Reparative dentin formation was more pronounced for defect sizes up to 2/1 mm3 when treated with CH, and completely bridged the surgically created dentin defects only after 30 days. However, reparative dentin upon CH treatment failed to completely bridge pulp chamber exposure for 2/2 defects. By contrast, TM treatment only yielded mild reparative dentin bridging for defects up to 1/1, but not for either 2/1 or 2/2 defects at 30 days. Inflammatory responses of the exposed dental pulp tissue were more robust with the TM group than with the CH group. Thus, dental pulp tissue possesses a capacity for spontaneous repair by the formation of reparative dentin in this preclinical model, but only up to a defect size of -2 mm in diameter and 1 mm in depth. All observations are based on 30 days post-treatment in the canine model. These findings may serve as baseline for regenerative endodontic studies.

The Effect of Chemically Modified Tetracycline-3 on the Progression of Dental Caries in Rats.

PubMed

Xu, Jun; Miao, Congcong; Tian, Zhenchuan; Li, Jinlu; Zhang, Chunmei; Yang, Dongmei

2018-02-07

Matrix metalloproteinases (MMPs) exist in human saliva and dentin and play an important role in the degradation of organic matrix in teeth. Chemically modified tetracycline-3 (CMT-3) is an inhibitor of MMPs. CMT-3 has been used experimentally to treat caries since 1999, but no distinction between dental caries prevalence and dentin caries prevalence has been described. A total of 65 Sprague-Dawley rats were randomly divided into three groups. The positive control group (25 rats) was inoculated with Streptococcus mutans (ATCC700610) and fed the cariogenic feed of improved Keyes Diet 2000. The CMT-3 group (25 rats) was also inoculated with S. mutans and fed the cariogenic feed of improved Keyes Diet 2000; the surfaces of rats' molars were daily treated with 0.02% CMT-3. The negative control group (15 rats) was only fed the standard rodent chow. At the end of the 10th week, the dental caries prevalence and dentin caries prevalence of each group were calculated, and the regions of caries were assessed. No caries was found in the negative control group. The dental caries prevalence of the CMT-3 and the positive control group was 75.0 and 83.3%, respectively (p > 0.05, Table 2). The dentin caries prevalence of the CMT-3 and the positive control group was 33.3 and 70.8%, respectively (p < 0.05, Table 2). The Keyes scoring of dentin caries in the CMT-3 group was significantly lower than that in the positive control group (p < 0.05, Table 3). CMT-3 had no effect on the prevalence of dental caries, but could lower the prevalence and slow down the progression of dentin caries. © 2018 S. Karger AG, Basel.

The effect of a triclosan/copolymer/fluoride 
toothpaste on plaque formation, gingivitis, and 
dentin hypersensitivity: A single-blinded 
randomized clinical study.

PubMed

Al Habashneh, Rola; Farasin, Rawan; Khader, Yousef

2017-01-01

The daily removal of supragingival dental plaque is a key factor in the prevention of gingivitis. The aim of the study was to compare the gingival health benefits of a triclosan/copolymer/fluoride toothpaste (Colgate Total, a fluoride toothpaste containing an antiseptic) to a commercially available toothpaste containing 0.243% sodium fluoride in a silica base (Colgate Herbal, a conventional fluoride toothpaste with herbal extracts). A total of 50 patients with gingivitis and at least one sensitive tooth were included. The subjects were randomly stratified into two groups: Colgate Total toothpaste, and Colgate Herbal toothpaste. After a 4-week pre-experimental phase, baseline Plaque Index (Quigley-Hein Index) (PI), Gingival Index (GI), Gingival Bleeding Index (GBI), and Visual Analog Scale (VAS) were assessed. The PI, GI, GBI, and VAS were reexamined at weeks 4, 12, and 24 after the baseline. Fifty subjects complied with the protocol and completed the study. The conventional fluoride toothpaste with herbal extracts group and the fluoride toothpaste containing an antiseptic group exhibited significant reductions in PI, GI, GBI, and VAS over time. The amount of reduction after 6 months of the treatment was higher in the Total group compared to Herbal group (1.82 vs 1.39, P = .015 for PI; 0.67 vs 0.37, P < .005 for GI; and 56.64% vs 34.26%, P < .005 for GBI). No significant difference was seen for VAS. Twice daily brushing with a toothpaste containing 0.3% triclosan and polyvinyl methyl ether and maleic acid copolymer provides a more effective level of plaque control and gingival health with no effect on decreasing dentin hypersensitivity compared to conventional fluoride toothpaste. Toothpastes containing triclosan/copolymer, in addition to fluoride, result in a higher reduction in plaque, gingival inflammation, and gingival bleeding when compared with fluoride toothpastes without triclosan/copolymer.

Primum non nocere - The effects of sodium hypochlorite on dentin as used in endodontics.

PubMed

Gu, Li-Sha; Huang, Xue-Qing; Griffin, Brandon; Bergeron, Brian R; Pashley, David H; Niu, Li-Na; Tay, Franklin R

2017-10-01

The medical literature is replete with the maxim 'primum non nocere', cautioning health care providers to avoid doing any harm to human subjects in their delivery of medical care. Sodium hypochlorite (NaOCl) is a well-established irrigant for root canal treatment because of its antimicrobial and organic tissue remnant dissolution capability. However, little is known about the deleterious effect of this strong oxidizing agent on the integrity of human mineralized dentin. Iatrogenically-induced loss of dentin integrity may precipitate post-treatment root fracture and has potential medico-legal complications. In the present work, transmission electron microscopy provided evidence for collagen destruction in the surface/subsurface of dentin treated with high NaOCl concentrations and long contact times. Size exclusion chromatography showed that the hypochlorite anion, because of its small size, penetrated the water compartments of apatite-encapsulated collagen fibrils, degraded the collagen molecules and produced a 25-35µm thick, non-uniform "ghost mineral layer" with enlarged, coalesced dentinal tubules and their lateral branches. Fourier transform-infrared spectroscopy identified increases in apatite/collagen ratio in NaOCl-treated dentin. The apatite-rich, collagen-sparse dentin matrix that remained after NaOCl treatment is more brittle, as shown by the reductions in flexural strength. Understanding the deleterious effects of NaOCl on mineralized dentin enables one to balance the risks and benefits in using high NaOCl concentrations for lengthy periods in root canal debridement. Delineating the mechanism responsible for such a phenomenon enables high molecular weight, polymeric antimicrobial and tissue dissolution irrigants to be designed that abides by the maxim of 'primum non nocere' in contemporary medical practices. The antimicrobial and tissue-dissolution capacities of NaOCl render it a well-accepted agent for root canal debridement. These highly desirable properties, however, appear to be intertwined with the untoward effect of collagen matrix degradation within mineralized dentin. Because of its small size, the hypochlorite anion is capable of infiltrating mineralized collagen and destroying the collagen fibrils, producing a mineral-rich, collagen sparse ghost mineral matrix with reduced flexural strength. Findings from the present work challenge the biosafety of NaOCl when it is used in high concentrations and for lengthy time periods during root canal treatment, and laid the background work for future biomaterials design in debridement of the canal space. Published by Elsevier Ltd.

Effect of application mode on interfacial morphology and chemistry between dentin and self-etch adhesives

PubMed Central

Zhang, Ying; Wang, Yong

2012-01-01

Objective To investigate the influence of application mode on the interfacial morphology and chemistry between dentin and self-etch adhesives with different aggressiveness. Methods The occlusal one-third of the crown was removed from un-erupted human third molars, followed by abrading with 600 grit SiC under water. Rectangular dentin slabs were prepared by sectioning the tooth specimens perpendicular to the abraded surfaces. The obtained dentin slabs were treated with one of the two one-step self-etch adhesives: Adper Easy Bond (AEB, PH~2.5) and Adper Prompt L-Pop (APLP, PH~0.8) with (15s, active application) or without (15s, inactive application) agitation. The dentin slabs were fractured and the exposed adhesive/dentin (A/D) interfaces were examined with micro-Raman spectroscopy and scanning electron microscopy (SEM). Results The interfacial morphology, degree of dentin demineralization (DD) and degree of conversion (DC) of the strong self-etch adhesive APLP showed more significant dependence on the application mode than the mild AEB. APLP exhibited inferior bonding at the A/D interface if applied without agitation, evidenced by debonding from the dentin substrate. The DDs and DCs of the APLP with agitation were higher than those of without agitation in the interface, in contrast to the comparable DD and DC values of two AEB specimen groups with different application modes. Raman spectral analysis revealed the important role of chemical interaction between acid monomers of self-etch adhesives and dentin in the above observations. Conclusion The chemical interaction with dentin is especially important for improving the DC of the strong self-etching adhesive at the A/D interface. Agitation could benefit polymerization efficacy of the strong self-etch adhesive through enhancing the chemical interaction with tooth substrate. PMID:23153573

Validation of a Cariogenic Biofilm Model to Evaluate the Effect of Fluoride on Enamel and Root Dentine Demineralization.

PubMed

Fernández, Constanza E; Tenuta, Livia M A; Cury, Jaime A

2016-01-01

Due to gingival recession both enamel and root dentine are at risk of developing caries. Both tissues are exposed to a similar environment, however there is not a validated model to evaluate the effect of fluoride on these dental substrates simultaneously. Hence, this study aimed to validate a caries model to evaluate the effect of fluoride to prevent demineralization on enamel and root-dentine. Streptococcus mutans UA159 biofilms were formed on saliva-coated bovine enamel and root dentine slabs (n = 12 per group) mounted in the same well of culture plates. The biofilms were exposed 8×/day to 10% sucrose and treated 2×/day with fluoridated solutions containing 0, 150, 450, or 1,350 ppm F; thus, simulating the use of low to high fluoride concentration toothpastes. The pH values of the culture medium was monitored 2×/day as a biofilm acidogenicity indicator. After 96 h, biofilms were collected for fluoride concentration analysis. The percentage of surface hardness loss (%SHL) was calculated for slabs. The fluoride uptake by the enamel and dentine was also determined. The model showed a dose-response because the biofilm and fluoride uptake increased and %SHL decreased at increasing fluoride concentrations (p < 0.05). Fluoride in the biofilm formed on dentine and fluoride uptake by dentine were higher than those for enamel. With the same fluoride concentration treatment, the percentage of reduction of demineralization was lower for dentine than for enamel. In conclusion, the model was validated in terms of a dose-response effect of fluoride on enamel and root dentine. Furthermore, the findings support the clinical data, suggesting that higher fluoride concentrations are necessary to control caries of root dentine than of enamel.

The relation between the cell-mediated immunological response and the induction of circulating antibodies to collagen in guinea-pigs.

PubMed Central

Gentner, G J; Adelmann, B C

1976-01-01

Cutaneous delayed hypersensitivity reactions to collagen in guinea-pigs were partially but specifically suppressed if the animals had been pretreated with collagen and Freund's incomplete adjuvant. Such animals responded normally to skin-reactive factor prepared with ovalbumin. Lymphoid cells from animals with normal delayed hypersensitivity to collagen functioned normally in animals with suppressed skin reactivity. Cells from animals with suppressed delayed hypersensitivity were specifically, functionally impaired since they transferred delayed hypersensitivity into neutral recipients efficiently for PPD but not for collagen. Suppression could be induced in Cy-treated animals, and it persisted for at least 143 days. It is concluded that guinea-pigs with depressed delayed hypersensitivity to collagen are functionally impaired with respect to those T cells normally generated by induction of delayed hypersensitivity. PMID:1088420

Antibacterial effect of triantibiotic mixture, chlorhexidine gel, and two natural materials Propolis and Aloe vera against Enterococcus faecalis: An ex vivo study.

PubMed

Bazvand, Leila; Aminozarbian, Mohammad Ghasem; Farhad, Alireza; Noormohammadi, Hamid; Hasheminia, Seyed Mohsen; Mobasherizadeh, Sina

2014-07-01

The aim of this ex vivo study was to compare the antimicrobial effect of triantibiotic paste, 0.2% chlorhexidine gel, Propolis and Aloe vera on Enterococcus faecalis in deep dentin. Ninety fresh extracted single-rooted teeth were used in a dentin block model. Seventy-five teeth were infected with E. faecalis and divided into four experimental groups (n = 15). Experimental groups were treated with triantibiotic mixture with distilled water, 0.2% chlorhexidine gel, 70% ethanol + Propolis and Aloe vera. Fifteen teeth treated with distilled water as the positive control and 15 samples, free of bacterial contamination, were considered as the negative control. Gates-Glidden drill #4 was used for removal of surface dentin and Gates-Glidden drill #5 was used to collect samples of deep dentin. The samples were prepared and colony-forming units were counted. Data were analyzed by one-way ANOVA and post hoc Tukey tests. Statistical significance was defined at P < 0.05. Triantibiotic mixture group exhibited the least bacterial growth. However, the rate of bacterial growth showed no significant differences between chlorhexidine and Propolis groups (P > 0.05). Aloe vera had antibacterial effects on E. faecalis, but in comparison with other medicaments, it was less effective (P < 0.05). This experimental study showed that triantibiotic mixture, 0.2% chlorhexidine gel, Propolis and Aleo vera were relatively effective against E. faecalis. All the intracanal medicements had similar effects on E. faecalis in deep dentin except for Aloe vera.

Adipose tissue-deprived stem cells acquire cementoblast features treated with dental follicle cell conditioned medium containing dentin non-collagenous proteins in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wen, Xiujie; Nie, Xin; Zhang, Li

Highlights: {yields} In this study we examine the effects of dental follicle cell conditioned medium (DFCCM) containing dentin non-collagenous proteins (dNCPs) on differentiation of ADSCs. {yields} We examined that ADSCs treated with dNCPs/DFCCM underwent morphological changes and significantly lost their proliferative capacity. {yields} dNCPs/DFCCM enhanced the mineralization behaviour and mineralization-related marker expression of ADSCs. {yields} ADSCs acquired cementoblast features in vitro with dNCPs/DFCCM treatment. -- Abstract: Adipose tissue-derived stem cells (ADSCs), which are easily harvested and show excellent pluripotency potential, have generated considerable interest in regenerative medicine. In this study, the differentiation of ADSCs was assessed after treatment with dentalmore » follicle cell conditioned medium (DFCCM) containing dentin non-collagenous proteins (dNCPs). ADSCs exhibited a fibroblast-like morphology and high proliferative capacity. However, after treatment with dNCPs/DFCCM, ADSCs changed from a fibroblast-like to cementoblast-like morphology and significantly lost their proliferative capacity. Alkaline phosphatase activity and in vitro mineralization behaviour of ADSCs were significantly enhanced. Mineralization-related markers including cementum attachment protein, bone sialoprotein, osteocalcin, osteopontin and osteonectin were detected at mRNA or protein levels, whereas dentin sialophosphoprotein and dentin sialoprotein were not detected, implying a cementoblast-like phenotype. These results demonstrate that ADSCs acquired cementoblast features in vitro with dNCPs/DFCCM treatment and could be a potential source of cementogenic cells for periodontal regeneration.« less

Effect of Photo-Fenton Bleaching on Tetracycline-stained Dentin in vitro.

PubMed

Bennett, Zackary Yale; Walsh, Laurence James

2015-02-01

Tetracycline-stained tooth structure is difficult to bleach using nightguard tray methods. The possible benefits of in-office light-accelerated bleaching systems based on the photo-Fenton reaction are of interest as possible adjunctive treatments. This study was a proof of concept for possible benefits of this approach, using dentine slabs from human tooth roots stained in a reproducible manner with the tetracycline antibiotic demeclocycline hydrochloride. Color changes overtime in tetra-cycline stained roots from single rooted teeth treated using gel (Zoom! WhiteSpeed(®)) alone, blue LED light alone, or gel plus light in combination were tracked using standardized digital photography. Controls received no treatment. Changes in color channel data were tracked overtime, for each treatment group (N = 20 per group). Dentin was lighter after bleaching, with significant improvements in the dentin color for the blue channel (yellow shade) followed by the green channel and luminosity. The greatest changes occurred with gel activated by light (p < 0.0001), which was superior to effects seen with gel alone. Use of the light alone did not significantly alter shade. This proof of concept study demonstrates that bleaching using the photo-Fenton chemistry is capable of lightening tetracycline-stained dentine. Further investigation of the use of this method for treating tetracycline-stained teeth in clinical settings appears warranted. Because tetracycline staining may respond to bleaching treatments based on the photo-Fenton reaction, systems, such as Zoom! WhiteSpeed, may have benefits as adjuncts to home bleaching for patients with tetracycline-staining.

The effect of home-use and in-office bleaching treatments combined with experimental desensitizing agents on enamel and dentin

PubMed Central

Pintado-Palomino, Karen; Tirapelli, Camila

2015-01-01

Objective: This study aimed to evaluate in vitro the effect of formulations containing Biosilicate to treat enamel and dentin bovine samples exposed to dental bleaching agents. Materials and Methods: On enamel and dentin bleached with commercial gels containing 16% carbamide peroxide (CP) (14 days/4 h) or 35% hydrogen peroxide (single session/45 min), desensitizing dentifrices (Sensodyne®; experimental dentifrice of Biosilicate®; Odontis RX®; Sorriso®) were applied along 14 days and desensitizing pastes (Biosilicate®/water 1:1; Dessensebilize NanoP®; Bioglass type 45S5/water 1:1) were applied on days 1, 3, 7, 10 and 14. Distilled water was the control. Microhardness (MH) and roughness measurements were the variables measured on the samples before and after the treatments. Student's t-test analyzed differences before and after the treatments. Two-way analysis of variance and post-hoc Tukey test analyzed differences among the factors desensitizing, bleaching agents and substrate. Results: Tukey test showed no differences in roughness for both bleaching treatments and among the desensitizing agents (P > 0.05). Differences in MH appeared on enamel treated with in-home bleaching when control group (lower values) was compared with Sensodyne, Biosilicate dentifrice, Biosilicate paste, and Bioglass paste (higher values). Comparisons between desensitizing agents on dentin treated with both bleaching gels showed no statistical differences. Conclusions: The effect of formulations containing Biosilicate (Biosilicate dentifrice and paste) was significant in the MH of enamel bleached with 16% CP. PMID:25713487

The threshold effects of Nd and Ho: YAG laser-induced surface modification on demineralization of dentin surfaces.

PubMed

Kinney, J H; Haupt, D L; Balooch, M; White, J M; Bell, W L; Marshall, S J; Marshall, G W

1996-06-01

Laser irradiation alters the structure of dentin and produces surface layers that give the appearance of being more enamel-like. The laser-modified surface may be more resistant to demineralization; hence, many investigators are proposing continued development of the laser as a possible preventive treatment for caries. The purpose of this study was to explore the morphological changes that occur in dentin when treated at threshold illuminance with two clinically interesting laser wavelengths, and to evaluate the effectiveness of the laser-treated surface at resisting demineralization in an acid-gel solution. The Nd: YAG laser (wavelength 1060 nm) produced significant recrystallization and grain growth of the apatite, without the formation of second phases such as beta-tricalcium phosphate. This recrystallized surface layer showed resistance to demineralization; however, the layer did not provide protection of the underlying dentin from demineralization because of cracks and macroscopic voids that allowed for penetration of the demineralizing gel. The Ho: YAG laser-treated surface (wavelength 2100 nm) did not show significant evidence of recrystallization and grain growth, and only a trace amount of an acid-resistant layer was observed with demineralization. It is speculated that the Ho:YAG laser is coupling with absorbed water, and that the heat transfer from the water to the mineral phase is inefficient. For the purposes of creating a demineralization-resistant layer, threshold illuminance with both Nd: YAG and Ho: YAG was ineffective.

Prevention of root caries with dentin adhesives.

PubMed

Grogono, A L; Mayo, J A

1994-04-01

This in vitro investigation determined the feasibility of using dentin adhesives to protect root surfaces against caries. The roots of 22 recently extracted human teeth were all painted with a protective lacquer leaving two unprotected small windows. On each specimen, one window (control) was left untreated and the other window (experimental) was treated using a dentin adhesive (Scotchbond Multi-Purpose). The roots were then immersed in an in vitro acetate/calcium/phosphate demineralization model at pH 4.3. After 70 days, the samples were removed and sectioned through the windows. The undecalcified ground sections were examined under transmitted and polarized light. Lesions characteristic of natural root caries were seen in the untreated control windows. No such lesions were apparent in the experimental windows. The results of this preliminary study suggest that dentin adhesives may provide protection against root caries.

Fourier transform infrared photoacoustic spectroscopy study of physicochemical interaction between human dentin and etch-&-rinse adhesives in a simulated moist bond technique.

PubMed

Ubaldini, Adriana L M; Baesso, Mauro L; Sehn, Elizandra; Sato, Francielle; Benetti, Ana R; Pascotto, Renata C

2012-06-01

The purpose of this study was to provide the physicochemical interactions at the interfaces between two commercial etch-&-rinse adhesives and human dentin in a simulated moist bond technique. Six dentin specimens were divided into two groups (n=3) according to the use of two different adhesive systems: (a) 2-hydroxyethylmethacrylate (HEMA) and 4-methacryloxyethyl trimellitate anhydrate (4-META), and (b) HEMA. The Fourier transform infrared photoacoustic spectroscopy was performed before and after dentin treatment with 37% phosphoric acid, with adhesive systems and also for the adhesive systems alone. Acid-conditioning resulted in a decalcification pattern. Adhesive treated spectra subtraction suggested the occurrence of chemical bonding to dentin expressed through modifications of the OH stretching peak (3340 cm(-1)) and symmetric CH stretching (2900 cm(-1)) for both adhesives spectra; a decrease of orthophosphate absorption band (1040 to 970 cm(-1)) for adhesive A and a better resolved complex band formation (1270 to 970 cm(-1)) for adhesive B were observed. These results suggested the occurrence of chemical bonding between sound human dentin and etch-&-rinse adhesives through a clinical typical condition.

Effects of different lasers on organic/inorganic ratio of radicular dentin.

PubMed

Lopes, F C; Roperto, R; Akkus, A; Akkus, O; Souza-Gabriel, A E; Sousa-Neto, M D

2016-04-01

The aim of this study was to evaluate the chemical stability of endodontic-treated root dentin after different laser irradiations through Raman spectroscopy. Fifty maxillary canines were selected and prepared with K3 system. Roots were randomly distributed into five groups (n = 10) according to the surface treatment: GI (water), GII (NaOCl + EDTA), GIII (NaOCl + EDTA + 980 nm Diode laser), GIV (NaOCl + EDTA+ 1064 nm Nd: YAG laser) and GV (NaOCl + EDTA+ 2780 nm Er,Cr: YSGG laser). Lasers were applied for 20 s. Samples were bisected, and the organic and inorganic content of dentin was analyzed by Raman spectroscopy. Data were submitted to ANOVA and Tukey tests (p < 0.05). None of the surface treatments alter the inorganic content (cts) (p = 0.183). Roots irradiated with Er,Cr: YSGG laser had a reduced collagen content (GV-290.7 ± 41.7) compared with the water-treated roots (GI-328.3 ± 63.5) and those treated with NaOCl + EDTA (GII-333.9 ± 55.8). Roots irradiated with Er,Cr: YSGG laser also showed a higher inorganic/organic ratio (GV-9.5 ± 1.1) than roots treated with water (GI-7.7 ± 1.5), NaOCl + EDTA (GII-8.0 ± 1.4) and diode laser (GIII-8.2 ± 1.6). Both organic and inorganic contents increased from cervical to apical thirds in all groups. None of the surface treatments were able to promote changes in the inorganic content of the root dentin; treatment with NaOCl + EDTA combined with Er,Cr: YSGG altered collagen.

[Effect of a nano hydroxyapatite desensitizing paste application on dentin bond strength of three self-etch adhesive systems].

PubMed

Pei, D D; Liu, S Y; Yang, H Y; Gan, J; Huang, C

2017-05-09

Objective: To evaluate a nano-hydroxyapatite (nano-HA) desensitizing paste application on the bond strength of three self-etch adhesives. Methods: Three dentin specimens of about 1 mm thick were cut from two teeth. Scanning electron microscope (SEM) was used to evaluate the dentin surfaces without treatment, after citric acid treatment and after nano-HA treatment. Thirty-six intact third molars extracted for surgical reasons were cut to remove the occlusal enamel with isomet, and then were etched with 1% citric acid for 20 s to simulate the sensitive dentin and divided into two groups randomly using a table of random numbers ( n= 18): the control group (no treatment) and the HA treated group (with nano-HA paste treatment). Each group was divided into three subgroups randomly using a table of random numbers ( n= 6). Subgroup A, B and C was bonded with G-Bond, Clearfil S(3) Bond and FL-Bond Ⅱ according to the manufacture's instruction separately. At 24 h after bonding procedure, and after water storage for 6 months, microtensile bond strength of the specimens was tested and the failure mode was analyzed. Results: SEM obeservation showed that citric acid could open the dentin tubules to set up the sensitive dentin model, and the nano-HA could occlude the dentin tubules effectively. For subgroup A, bonding strength of specimens treated with nano-HA ([41.14±8.91] MPa) was significantly high than that of the control group ([34.27±6.16] MPa) at 24 h after bonding procedure ( P< 0.05). However, after 6 month water ageing, the bonding strength of the control group and the HA treated group showed no significant difference ( P> 0.05). For subgroup B, specimens with nano-HA application showed lower bonding strength ([30.87±6.41] MPa) than that of the control group ([36.73±5.82] MPa) at 24 h after bonding procedure ( P< 0.05), and after 6 month water ageing, the bond strength of nano-HA application ([25.73±6.99] MPa) was also lower than that of the control group ([32.33±5.08] MPa) ( P< 0.05). For subgroup C, the bond strength of the control group and the HA treated group have no significant difference either before or after 6 month water ageing ( P> 0.05). Failure mode analysis showed that more than half of the samples in all groups were adhesive failure. Conclusions: Nano-HA treatment decreased the bond strength of subgroup B, while had no adverse effect on subgroup A and subgroup C.

Minocycline Prevents Muscular Pain Hypersensitivity and Cutaneous Allodynia Produced by Repeated Intramuscular Injections of Hypertonic Saline in Healthy Human Participants.

PubMed

Samour, Mohamad Samir; Nagi, Saad Saulat; Shortland, Peter John; Mahns, David Anthony

2017-08-01

Minocycline, a glial suppressor, prevents behavioral hypersensitivities in animal models of peripheral nerve injury. However, clinical trials of minocycline in human studies have produced mixed results. This study addressed 2 questions: can repeated injections of hypertonic saline (HS) in humans induce persistent hypersensitivity? Can pretreatment with minocycline, a tetracycline antibiotic with microglial inhibitory effects, prevent the onset of hypersensitivity? Twenty-seven healthy participants took part in this double-blind, placebo-controlled study, consisting of 6 test sessions across 2 weeks. At the beginning of every session, pressure-pain thresholds of the anterior muscle compartment of both legs were measured to determine the region distribution and intensity of muscle soreness. To measure changes in thermal sensitivity in the skin overlying the anterior muscle compartment of both legs, quantitative sensory testing was used to measure the cutaneous thermal thresholds (cold sensation, cold pain, warm sensation, and heat pain) and a mild cooling stimulus was applied to assess the presence of cold allodynia. To induce ongoing hypersensitivity, repeated injections of HS were administered into the right tibialis anterior muscle at 48-hour intervals. In the final 2 sessions (days 9 and 14), only sensory assessments were done to plot the recovery after cessation of HS administrations and drug washout. By day 9, nontreated participants experienced a significant bilateral increase in muscle soreness (P < .0001), accompanied by the emergence of bilateral cold allodynia in 44% of participants, thus confirming the effectiveness of the model. Placebo-treated participants experienced a bilateral 35% alleviation in muscle soreness (P < .0001), with no changes to the prevalence of cold allodynia. In contrast, minocycline-treated participants experienced a bilateral 70% alleviation in muscle soreness (P < .0001), additionally, only 10% of minocycline-treated participants showed cold allodynia. This study showed that repeated injections of HS can induce a hypersensitivity that outlasts the acute response, and the development of this hypersensitivity can be reliably attenuated with minocycline pretreatment. Four repeated injections of HS at 48-hour intervals induce a state of persistent hypersensitivity in healthy human participants. This hypersensitivity was characterized by bilateral muscular hyperalgesia and cutaneous cold allodynia, symptoms commonly reported in many chronic pain conditions. Minocycline pretreatment abolished the development of this state. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Clinical outcomes for teeth treated with electrospun poly(ε-caprolactone) fiber meshes/mineral trioxide aggregate direct pulp capping.

PubMed

Lee, Li-Wan; Hsiao, Sheng-Huang; Hung, Wei-Chiang; Lin, Yun-Ho; Chen, Po-Yu; Chiang, Chun-Pin

2015-05-01

Mineral trioxide aggregate (MTA) is a biocompatible material for direct pulp capping. This study was designed to compare the clinical outcomes of pulp-exposed teeth treated with either poly(ε-caprolactone) fiber mesh (PCL-FM) as a barrier for MTA (so-called PCL-FM/MTA) or MTA direct pulp capping. Sixty human vital teeth were evenly divided into 4 groups (n = 15 in each group). Teeth in groups 1 and 3 had pulp exposure <1 mm in diameter, whereas teeth in groups 2 and 4 had pulp exposure of 1-1.5 mm in diameter. Teeth in groups 1 and 2 were treated with PCL-FM/MTA direct pulp capping, and those in groups 3 and 4 were treated with MTA direct pulp capping. Teeth treated with PCL-FM/MTA direct pulp capping needed a significantly shorter mean duration for dentin bridge formation than teeth treated with MTA direct pulp capping. Moreover, teeth with pulp exposure <1.0 mm in diameter needed a significantly shorter mean duration for dentin bridge formation than teeth with pulp exposure of 1-1.5 mm in diameter after either PCL-FM/MTA or MTA direct pulp capping treatment. In addition, teeth treated with PCL-FM/MTA direct pulp capping formed an approximately 3-fold thicker dentin bridge than teeth treated with MTA direct pulp capping 8 weeks or 3 months later. Furthermore, none of the teeth treated with PCL-FM/MTA direct pulp capping showed tooth discoloration after treatment for 3 months. PCL-FM/MTA is a better combination material than MTA alone for direct pulp capping of human permanent teeth. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Hypersensitivity reactions to etoposide.

PubMed

Hoetelmans, R M; Schornagel, J H; ten Bokkel Huinink, W W; Beijnen, J H

1996-04-01

To report a hypersensitivity reaction to etoposide occurring in a patient after 2 months of drug therapy. A 20-year-old man with a diagnosis of testicular carcinoma was treated with bleomycin, etoposide, and cisplatin (BEP regimen). After dose 20 of etoposide, an exanthema was noted, which was attributed to etoposide. The patient had received 19 doses of etoposide during the previous 2 months without any sign of an allergic reaction. Rechallenging the patient with etoposide from another batch resulted in recurrence of the exanthema. Both etoposide and its excipient (polysorbate 80) are suspected of causing hypersensitivity reactions. Although the exact mechanism of the hypersensitivity reaction is not known, it is believed to be of nonimmunogenic origin. With a lower rate of infusion of etoposide and/or by premedication with antihistamines and/or corticosteroids, hypersensitivity reactions to etoposide might be prevented in patients with a history of hypersensitivity to this drug.

Reflux Hypersensitivity: A New Functional Esophageal Disorder.

PubMed

Yamasaki, Takahisa; Fass, Ronnie

2017-10-30

Reflux hypersensitivity, recently introduced by Rome IV as a new functional esophageal disorder, is currently considered as the presence of typical heartburn symptoms in patients with normal upper endoscopy and esophageal biopsies, normal esophageal pH test and with evidence of a close correlation between patients' heartburn and reflux events. Reflux hypersensitivity is very common and together with functional heartburn accounts for more than 90% of the heartburn patients who failed treatment with proton pump inhibitor twice daily. In addition, reflux hypersensitivity affects primarily young to middle aged women, commonly overlaps with another functional gastrointestinal disorders, and is often associated with some type of psychological comorbidity. Diagnosis is made by using endoscopy with esophageal biopsies, pH-impedance, and high-resolution esophageal manometry. Reflux hypersensitivity is primarily treated with esophageal neuromodulators, such as tricyclic anti-depressants and selective serotonin reuptake inhibitors among others. Surgical anti-reflux management may also play an important role in the treatment of reflux hypersensitivity.

Interferon-gamma improves impaired dentinogenic and immunosuppressive functions of irreversible pulpitis-derived human dental pulp stem cells

PubMed Central

Sonoda, Soichiro; Yamaza, Haruyoshi; Ma, Lan; Tanaka, Yosuke; Tomoda, Erika; Aijima, Reona; Nonaka, Kazuaki; Kukita, Toshio; Shi, Songtao; Nishimura, Fusanori; Yamaza, Takayoshi

2016-01-01

Clinically, irreversible pulpitis is treated by the complete removal of pulp tissue followed by replacement with artificial materials. There is considered to be a high potential for autologous transplantation of human dental pulp stem cells (DPSCs) in endodontic treatment. The usefulness of DPSCs isolated from healthy teeth is limited. However, DPSCs isolated from diseased teeth with irreversible pulpitis (IP-DPSCs) are considered to be suitable for dentin/pulp regeneration. In this study, we examined the stem cell potency of IP-DPSCs. In comparison with healthy DPSCs, IP-DPSCs expressed lower colony-forming capacity, population-doubling rate, cell proliferation, multipotency, in vivo dentin regeneration, and immunosuppressive activity, suggesting that intact IP-DPSCs may be inadequate for dentin/pulp regeneration. Therefore, we attempted to improve the impaired in vivo dentin regeneration and in vitro immunosuppressive functions of IP-DPSCs to enable dentin/pulp regeneration. Interferon gamma (IFN-γ) treatment enhanced in vivo dentin regeneration and in vitro T cell suppression of IP-DPSCs, whereas treatment with tumor necrosis factor alpha did not. Therefore, these findings suggest that IFN-γ may be a feasible modulator to improve the functions of impaired IP-DPSCs, suggesting that autologous transplantation of IFN-γ-accelerated IP-DPSCs might be a promising new therapeutic strategy for dentin/pulp tissue engineering in future endodontic treatment. PMID:26775677

Effect of photoactivated riboflavin on the biodegradation-resistance of root-dentin collagen.

PubMed

Priyadarshini, Balasankar Meera; Lu, Thong Beng; Fawzy, Amr S

2017-12-01

This study was conducted to evaluate the effect of UVA-activated 1% riboflavin solution on structural integrity; mechanical properties and stability; and collagenase-mediated collagen solubilisation resistance of demineralized root dentin collagen matrix. Root dentin specimens demineralized with 17% EDTA for 7days were treated with 1% RF for 1min followed by UVA photo-activation at intensity 7mW/cm 2 for 1min. Control specimens were completely devoid of riboflavin and/or UVA treatments. Specimens were challenged with bacterial collagenase type-I solution for different time-periods at 37°C. Collagen solubilisation resistance was evaluated in terms of hydroxyproline (HYP) liberation. Mechanical characterization of dentin specimens before and after 24h of exposure to collagenase solution was done in terms of apparent-elastic modulus (E appr ) and ultimate tensile strength (UTS). Variations in dentin collagen-network structure with exposure time in collagenase were visualized by TEM. Crosslinking dentin with UVA-activated riboflavin significantly decreased HYP release and increased E appr and UTS compared to control specimens with storage time in collagenase. Moreover, crosslinked specimens showed higher structural resistance to collagenase effect reflected from dense, well-formed collagen fibrils-network with characteristic collagen cross-banding. UVA-activated riboflavin treatment increased collagenase-mediated collagen degradation resistance and enhanced mechanical stability against collagenase challenges of root dentin after EDTA demineralization. Copyright © 2017 Elsevier B.V. All rights reserved.

Reducing the risk of sensitivity and pulpal complications after the placement of crowns and fixed partial dentures.

PubMed

Brännström, M

1996-10-01

Sensitivity after cementation of a crown with glass-ionomer cement is often attributed to an adverse effect on the pulp by the luting agent. Most permanent restorative materials in common use today do not tend to irritate the pulp; the main cause of pulpal damage is infection, the bacteria originating in the smear layer or deep in the dental tubules, inaccessible to caries-excavating procedures. A poorly fitting provisional crown may expose cut dentin to the oral fluids, and mechanical trauma caused by frictional heat during preparation may also damage the pulp. The following precautions are recommended during precementation procedures to reduce the risk of an inflammatory response in the pulp: (1) The provisional crown should be well fitting, covering cervical dentin but not impinging on the periodontal tissues. The permanent crown should be cemented as soon as possible. (2) The superficial smear layer should be removed and the dentinal surface should be treated with an antibacterial solution before the provisional crown is placed. (3) To decrease dentinal permeability under the provisional crown, the dentinal surface should be covered with a liner that can be easily removed before final cementation. (4) to ensure optimal mircomechanical bonding, the dentinal surface should be thoroughly cleaned, and the dentin should be kept moist until cementation. (5) The occlusion should be carefully checked before cementation of the crown.

Atraumatic Restorative Treatment: Restorative Component.

PubMed

Leal, Soraya; Bonifacio, Clarissa; Raggio, Daniela; Frencken, Jo

2018-01-01

Atraumatic restorative treatment (ART) is a method of managing dental caries based on 2 pillars: sealants for preventing carious lesions in pits and fissures, and restorations for cavitated dentine carious lesions. ART uses only hand instruments for opening/enlarging the cavity and for removing carious tissue. The amount of carious tissue that should be removed depends mainly on the cavity depth. In cavities of shallow and medium depth, carious tissue is removed up to firm dentine. In deep/very deep cavities, in which there is no sign of pulp exposure, pulp inflammation and/or history of spontaneous pain, some soft dentine can be left in the pulpal floor/wall with the aim of avoiding pulp exposure. The ART restorative method is indicated for treating single-surface cavities in primary and permanent teeth, and in multiple-surface cavities in primary teeth. Insufficient information is available to conclude on its use for treating multiple-surface cavities in permanent teeth. © 2018 S. Karger AG, Basel.

Ions-modified nanoparticles affect functional remineralization and energy dissipation through the resin-dentin interface.

PubMed

Toledano, Manuel; Osorio, Raquel; Osorio, Estrella; Medina-Castillo, Antonio Luis; Toledano-Osorio, Manuel; Aguilera, Fátima S

2017-04-01

The aim of this study was to evaluate changes in the mechanical and chemical behavior, and bonding ability at dentin interfaces infiltrated with polymeric nanoparticlesstandard deviations and modes of failure are (NPs) prior to resin application. Dentin surfaces were treated with 37% phosphoric acid followed by application of an ethanol suspension of NPs, Zn-NPs or Ca-NPs followed by the application of an adhesive, Single Bond (SB). Bonded interfaces were stored for 24h, submitted to microtensile bond strength test, and evaluated by scanning electron microscopy. After 24h and 21 d of storage, the whole resin-dentin interface adhesive was evaluated using a Nano-DMA. Complex modulus, storage modulus and tan delta (δ) were assessed. AFM imaging and Raman analysis were performed. Bond strength was not affected by NPs infiltration. After 21 d of storage, tan δ generally decreased at Zn-NPs/resin-dentin interface, and augmented when Ca-NPs or non-doped NPs were used. When both Zn-NPs and Ca-NPs were employed, the storage modulus and complex modulus decreased, though both moduli increased at the adhesive and at peritubular dentin after Zn-NPs infiltration. The phosphate and the carbonate peaks, and carbonate substitution, augmented more at interfaces promoted with Ca-NPs than with Zn-NPs after 21 d of storage, but crystallinity did not differ at created interfaces with both ions-doped NPs. Crosslinking of collagen and the secondary structure of collagen improved with Zn-NPs resin-dentin infiltration. Ca-NPs-resin dentin infiltration produced a favorable dissipation of energy with minimal stress concentration trough the crystalline remineralized resin-dentin interface, causing minor damage at this structure. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bonding performance of experimental bioactive/biomimetic self-etch adhesives doped with calcium-phosphate fillers and biomimetic analogs of phosphoproteins.

PubMed

Abuna, Gabriel; Feitosa, Victor P; Correr, Americo Bortolazzo; Cama, Giuseppe; Giannini, Marcelo; Sinhoreti, Mario A; Pashley, David H; Sauro, Salvatore

2016-09-01

This study examined the bonding performance and dentin remineralization potential of an experimental adhesive containing calcium-phosphate (Ca/P) micro-fillers, and self-etching primers doped with phosphoprotein biomimetic analogs (polyacrylic acid-(PAA) and/or sodium trimetaphosphate-(TMP)). Experimental self-etching primers doped with biomimetic analogs (PAA and/or TMP), and an adhesive containing Ca(2+), PO4(-3)-releasing micro-fillers (Ca/P) were formulated. Sound human dentin specimens were bonded and cut into sticks after aging (24h or 6 months) under simulated pulpal pressure (20cm H2O), and tested for microtensile bond strength (μTBS). Results were analyzed using two-way ANOVA and Tukey's test (p<0.05). Interfacial silver nanoleakage was assessed using SEM. Remineralization of EDTA-demineralized dentin was assessed through FTIR and TEM ultrastructural analysis. Application of the Ca/P-doped adhesive with or without dentin pre-treatments with the primer containing both biomimetic analogs (PAA and TMP) promoted stable μTBS over 6 months. Conversely, μTBS of the control primer and filler-free adhesive significantly decreased after 6 months. Nanoleakage decreased within the resin-dentin interfaces created using the Ca/P-doped adhesives. EDTA-demineralized dentin specimens treated the Ca/P-doped adhesive and the primer containing PAA and TMP showed phosphate uptake (FTIR analysis), as well as deposition of needle-like crystallites at intrafibrillar level (TEM analysis). The use of Ca/P-doped self-etching adhesives applied in combination with analogs of phosphoproteins provides durable resin-dentin bonds. This approach may represent a suitable bonding strategy for remineralization of intrafibrillar dentin collagen within the resin-dentin interface. Copyright © 2016 Elsevier Ltd. All rights reserved.

Structural analysis of strontium in human teeth treated with surface pre-reacted glass-ionomer filler eluate by using extended X-ray absorption fine structure analysis.

PubMed

Uo, Motohiro; Wada, Takahiro; Asakura, Kiyotaka

2017-03-31

The bioactive effects of strontium released from surface pre-reacted glass-ionomer (S-PRG) fillers may aid in caries prevention. In this study, the local structure of strontium taken up by teeth was estimated by extended X-ray absorption fine structure analysis. Immersing teeth into S-PRG filler eluate increased the strontium content in enamel and dentin by more than 100 times. The local structure of strontium in enamel and dentin stored in distilled water was the same as that in synthetic strontium-containing hydroxyapatite (SrHAP). Moreover, the local structure of strontium in enamel and dentin after immersion in the S-PRG filler eluate was also similar to that of SrHAP. After immersion in the S-PRG filler eluate, strontium was suggested to be incorporated into the hydroxyapatite (HAP) of enamel and dentin at the calcium site in HAP.

Fluorine analysis of human dentin surrounding resin composite after fluoride application by μ-PIGE/PIXE analysis

NASA Astrophysics Data System (ADS)

Okuyama, Katsushi; Komatsu, Hisanori; Yamamoto, Hiroko; Pereira, Patricia N. R.; Bedran-Russo, Ana K.; Nomachi, Masaharu; Sato, Takahiro; Sano, Hidehiko

2011-10-01

The use of fluoride for the prevention of caries is based on the transformation of hydroxylapatite to fluoroapatite in the presence of fluoride ions, thereby strengthening tooth structure. Adhesion of dentin and resin composite (tooth-colored restoration material) requires a dentin bonding system, since resin composite is not able to adhere to dentin directly. Demineralization of dentin by acid etching is an important step in the dentin bonding system, however, demineralization also introduces weaknesses in tooth structure. If the demineralized dentin could be strengthened by the application of fluoride, then the dentin-resin composite bond strength might also improve. To test this hypothesis, the present study evaluated the influence of fluoride applications on the strength of the dentin-resin composite bond by (1) tensile strength testing analyses, (2) SEM analyses of tooth structure, and (3) detection of calcium (Ca) and fluorine (F) distribution patterns by micro proton-induced X-ray emission (μ-PIXE) and micro proton-induced gamma-ray emission (μ-PIGE) analyses conducted at the Takasaki Ion Accelerators for Advanced Radiation Application (TIARA) at the Takasaki Advanced Radiation Research Institute (TARRI). In this study, the dentin in extracted human molars was exposed by grinding and the dentin was etched with 35% phosphoric acid. Fluoride was applied at two concentrations, 0.022% (100 ppm F) and 2.21% (10,000 ppm F) NaF solution, for two time periods, 30 and 60 s, prior to bonding the resin composite with the treated dentin. Controls were prepared in the same manner, but without the fluoride application. Bond strength was measured with a micro-tensile testing unit, and the fluorine and calcium distributions at the interface between dentin and resin composite were detected by μ-PIGE and μ-PIXE analysis, respectively. Results indicate that the 10,000 ppm F applications resulted in higher bond strengths than observed in either the 100 ppm F applications or the control group. In addition, PIGE analyses showed high concentrations of fluorine in the hybrid bonding layer of the 10,000 ppm F samples, suggesting that the fluorine contributes to the strength of the dentin-resin composite bond. Detection of fluoroapatite within the hybrid bonding layer suggests that bond strength involves remineralization processes.

Effect of different irrigation protocols on the radicular dentin interface and bond strength with a metacrylate-based endodontic sealer.

PubMed

Gonçalves, Lisandro; Silva-Sousa, Yara Teresinha Correa; Raucci Neto, Walter; Teixeira, Cleonice Silveira; Sousa-Neto, Manoel Damião; Alfredo, Edson

2014-06-01

This study assessed the influence of different endodontic chemical substances on the adhesion of the Epiphany SE/Resilon system (with and without resinous solvent) to radicular dentin walls, using the push-out test and scanning electron microscopy (SEM). Forty-eight root canals of human canines were prepared biomechanically with ProTaper rotary files (crown-down technique) and the radicular dentin was treated with either 17% EDTA, 2% chlorhexidine gel (CHX) or 2.5% NaOCl (control). The root canals were filled with Resilon cones and Epiphany SE sealer with and without resinous solvent. Six groups of eight canals each had their roots sectioned transversally to obtain 1-mm thick slices. Data were subjected to statistical analysis by ANOVA and Tukey's tests. The specimens treated with 17% EDTA (1.59 ± 0.91) presented higher bond strength (P < 0.05) than those treated with 2.5% NaOCl (0.93 ± 0.27) and 2% CHX (0.92 ± 0.22). Significantly higher bond strength (P < 0.05) was observed when the Epiphany SE was prepared with (1.37 ± 0.78) than without (0.92 ± 0.33) solvent. Adhesive failures were predominant in all groups. SEM analysis showed greater homogeneity of the filling mass when the solvent was added to the sealer. Treatment of root canal walls with 17% EDTA, and addition of a resinous solvent to Epiphany SE produced the highest adhesion to radicular dentin. © 2014 Wiley Periodicals, Inc.

Zinc incorporation improves biological activity of beta-tricalcium silicate resin-based cement.

PubMed

Osorio, Raquel; Yamauti, Monica; Sauro, Salvatore; Watson, Tim F; Toledano, Manuel

2014-11-01

Matrix metalloproteinase (MMP) inhibition may improve endodontic treatment prognosis. The purpose of this study was to determine if zinc incorporation into experimental resin cements containing bioactive fillers may modulate MMP-mediated collagen degradation of dentin. Human dentin samples untreated and demineralized using 10% phosphoric acid or 0.5 mol/L EDTA were infiltrated with the following experimental resins: (1) unfilled resin, (2) resin with Bioglass 45S5 particles (OSspray, London, UK), (3) resin with beta-tricalcium silicate particles (βTCS), (4) resin with zinc-doped Bioglass 45S5, and (5) resin with zinc-doped βTCS particles. The specimens were stored in artificial saliva (for 24 hours, 1 week, and 4 weeks) and submitted to radioimmunoassay to quantify C-terminal telopeptide. Scanning electron microscopy analysis was also undertaken on dentin samples after 4 weeks of storage. Collagen degradation was prominent both in phosphoric acid and EDTA-treated dentin. Resin infiltration strongly reduced MMP activity in demineralized dentin. Resin containing Bioglass 45S5 particles exerted higher and stable protection of collagen. The presence of zinc in βTCS particles increases MMP inhibition. Different mineral precipitation was attained in dentin infiltrated with the resin cements containing bioactive fillers. MMP degradation of dentin collagen is strongly reduced after resin infiltration of dentin. Zinc incorporation in βTCS particles exerted an additional protection against MMP-mediated collagen degradation. However, it did not occur in resin containing Bioglass 45S5 particles, probably because of the formation of phosphate-zinc compounds. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

In vitro photodynamic antimicrobial chemotherapy in dentine contaminated by cariogenic bacteria

NASA Astrophysics Data System (ADS)

Melo, M. A. S.; de-Paula, D. M.; Lima, J. P. M.; Borges, F. M. C.; Steiner-Oliveira, C.; Nobre-Dos-Santos, M.; Zanin, I. C. J.; Barros, E. B.; Rodrigues, L. K. A.

2010-06-01

The development of a method to ensure bacterial-free substrates without extensive cavity preparation would be highly useful to dentistry, since there is no currently available effective method for killing residual bacteria in dentinal tissue. This randomized in vitro study determined parameters for using toluidine blue O (TBO) with a light-emitting diode (LED) for dentine caries disinfection and monitored intrapulpal/periodontal temperatures during irradiation. Occlusal human dentine slabs were immersed in Streptococcus mutans culture for demineralization induction. Slabs were allocated to 10 groups ( n = 15), which were treated with 0.1 mg ml-1 TBO with 5 min of incubation time or 0.9% NaCl solution for 5, 10 or 15 min, and submitted or not to irradiation for 5, 10 or 15 min (47, 94, and 144 J/cm2). Before and after treatments, dentine samples were analyzed with regard to S. mutans counts. In whole teeth, temperature in pulp and periodontium was measured by thermocouples during irradiation. Kruskal-Wallis/Student-Newman-Keuls, and ANOVA/Tukey test were respectively utilized to compare log reductions and temperature rises between groups. Bacterial reduction was observed when dentine was exposed to both TBO and LED at all irradiation times, as well as to LED alone for 10 and 15 min. Temperature increases lower than 2°C were observed for either pulp or periodontium. Concluding, LED combined with TBO is a safe and effective approach for dentine caries disinfection. Nevertheless, additional studies should be conducted to determine the influence of the irradiation in S. mutans viability in dentinal surface/tubules.

Influence of light intensity on surface free energy and dentin bond strength of core build-up resins.

PubMed

Shimizu, Y; Tsujimoto, A; Furuichi, T; Suzuki, T; Tsubota, K; Miyazaki, M; Platt, J A

2015-01-01

We examined the influence of light intensity on surface free energy characteristics and dentin bond strength of dual-cure direct core build-up resin systems. Two commercially available dual-cure direct core build-up resin systems, Clearfil DC Core Automix with Clearfil Bond SE One and UniFil Core EM with Self-Etching Bond, were studied. Bovine mandibular incisors were mounted in acrylic resin and the facial dentin surfaces were wet ground on 600-grit silicon carbide paper. Adhesives were applied to dentin surfaces and cured with light intensities of 0 (no irradiation), 200, 400, and 600 mW/cm(2). The surface free energy of the adhesives (five samples per group) was determined by measuring the contact angles of three test liquids placed on the cured adhesives. To determine the strength of the dentin bond, the core build-up resin pastes were condensed into the mold on the adhesive-treated dentin surfaces according to the methods described for the surface free energy measurement. The resin pastes were cured with the same light intensities as those used for the adhesives. Ten specimens per group were stored in water maintained at 37°C for 24 hours, after which they were shear tested at a crosshead speed of 1.0 mm/minute in a universal testing machine. Two-way analysis of variance (ANOVA) and a Tukey-Kramer test were performed, with the significance level set at 0.05. The surface free energies of the adhesive-treated dentin surfaces decreased with an increase in the light intensity of the curing unit. Two-way ANOVA revealed that the type of core build-up system and the light intensity significantly influence the bond strength, although there was no significant interaction between the two factors. The highest bond strengths were achieved when the resin pastes were cured with the strongest light intensity for all the core build-up systems. When polymerized with a light intensity of 200 mW/cm(2) or less, significantly lower bond strengths were observed. CONClUSIONS: The data suggest that the dentin bond strength of core build-up systems are still affected by the light intensity of the curing unit, which is based on the surface free energy of the adhesives. On the basis of the results and limitations of the test conditions used in this study, it appears that a light intensity of >400 mW/cm(2) may be required for achieving the optimal dentin bond strength.

In Vitro Evaluation of Shear Bond Strength of Nanocomposites to Dentin

PubMed Central

Vellanki, Vinay Kumar; Shetty, Vikram K; Kushwah, Sudhanshu; Goyal, Geeta; Chandra, S.M. Sharath

2015-01-01

Aims: To compare the shear bond strength of nanocomposites to dentin using three different types of adhesive systems; and to test few specimens under Scanning Electron Microscope (SEM) for analysing whether the bond failure is adhesive or cohesive. Materials and Methods: Sixty human premolar teeth were selected and were randomly grouped, with 20 specimens in each group: group 1 - fluoride releasing dentin bonding agent; group 2 - antibacterial containing dentin bonding agent; and group 3 - one step conventional self etch adhesive. Each group was treated with its respective bonding agents, composite resin build up was done, and shear bond strengths were tested using Instron Universal testing machine. Few of the specimens were tested under SEM. Results: The results were statistically analysed using One-way ANOVA and paired t-test. It was observed that group 3 has the highest shear bond strength followed by group 2, and then group 1. Adhesive failures and mixed failures were most frequent types of failures as seen under SEM. Conclusion: Addition of antimicrobial agent decreases the bond strength of dentin bonding agent and addition of fluoride further decreases the bond strength. From SEM results it can be concluded that the zone of failure could not be defined and also that the failure mode was independent of the dentin bonding agent used. PMID:25738077

Ethanol Wet-bonding Challenges Current Anti-degradation Strategy

PubMed Central

Sadek, F.T.; Braga, R.R.; Muench, A.; Liu, Y.; Pashley, D.H.; Tay, F.R.

2010-01-01

The long-term effectiveness of chlorhexidine as a matrix metalloproteinase (MMP) inhibitor may be compromised when water is incompletely removed during dentin bonding. This study challenged this anti-bond degradation strategy by testing the null hypothesis that wet-bonding with water or ethanol has no effect on the effectiveness of chlorhexidine in preventing hybrid layer degradation over an 18-month period. Acid-etched dentin was bonded under pulpal pressure simulation with Scotchbond MP and Single Bond 2, with water wet-bonding or with a hydrophobic adhesive with ethanol wet-bonding, with or without pre-treatment with chlorhexidine diacetate (CHD). Resin-dentin beams were prepared for bond strength and TEM evaluation after 24 hrs and after aging in artificial saliva for 9 and 18 mos. Bonds made to ethanol-saturated dentin did not change over time with preservation of hybrid layer integrity. Bonds made to CHD pre-treated acid-etched dentin with commercial adhesives with water wet-bonding were preserved after 9 mos but not after 18 mos, with severe hybrid layer degradation. The results led to rejection of the null hypothesis and highlight the concept of biomimetic water replacement from the collagen intrafibrillar compartments as the ultimate goal in extending the longevity of resin-dentin bonds. PMID:20940353

Effect of ethanol-wet bonding with hydrophobic adhesive on caries-affected dentine.

PubMed

Huang, Xueqing; Li, Li; Huang, Cui; Du, Xijin

2011-08-01

Frequently encountered in clinical practice, caries-affected dentine (CAD) is the most challenging bonding substrate. This study evaluated the effect of ethanol-wet bonding with hydrophobic adhesive to sound dentine and to CAD. In the control groups, prepared sound dentine and CAD were bonded with Adper Single Bond 2 using a traditional water-wet bonding technique. In the experimental groups, the specimens were treated as follows: Group 1, rinsed with stepwise ethanol dehydration; Group 2, immersion in 100% ethanol, three times, for 20 s each time; and Group 3, immersion in 100% ethanol for 20 s. Microtensile bond strength (μTBS) testing was used to evaluate the effects of the different protocols on bonding. The microhardness of debonded dentine surfaces was measured to ensure the presence of CAD. Interfacial nanoleakage was evaluated by field-emission scanning electron microscopy. Treatment significantly improved the μTBS in CAD in Groups 1 and 2, but had no effect on Group 3. Conversely, treatment significantly reduced the μTBS in sound dentine in Groups 2 and 3, but had no effect in Group 1. The presence of nanoleakage varied with the ethanol-wet protocol used. In conclusion, ethanol-wet bonding can potentially improve bond efficacy to CAD when an appropriate protocol is used. © 2011 Eur J Oral Sci.

Evaluation of dentin tubule occlusion after laser irradiation and desensitizing agent application.

PubMed

Kim, Min-Ho; Kim, Ryan Jin-Young; Lee, Woo-Cheol; Lee, In-Bog

2015-10-01

To evaluate the effects of lasers (Nd:YAG and Er:YAG) and of topical desensitizing agents on dentin tubule occlusion by measuring real-time dentin fluid flow (DFF). 32 molars were prepared with V-shape cavity at the cervical area, acid-etched, water rinsed, blotted dry, and treated with (1) Nd:YAG laser; (2) Er:YAG laser; (3) SuperSeal, a desensitizing agent; (4) ClinproXT, a resin-modified glass-ionomer (RMGI) varnish (n = 8 each). A real-time fluid flow measuring instrument (nano-Flow) was used to measure the DFF throughout the procedures. The DFF rates before and after the treatment were compared. Moreover, the surface topography of dentin tubules after each desensitizing method was examined using SEM. DFF varied among the groups. The DFF rate was significantly reduced after laser irradiation/application of the desensitizing agents (P < 0.05). ClinproXT showed the greatest reduction of DFF rate (71.9%), followed by the SuperSeal (34.8%) and laser groups (P< 0.05). However, there was no significant difference between the Nd:YAG (24.1%) and Er:YAG (20.6%) groups (P > 0.05). In SEM images, narrowed dentin tubules were observed in both lased groups and SuperSeal group. In the ClinproXT group, the occluded dentin tubules by the RMGI covering were observed.

MECHANISMS IN THE SUPPRESSION OF DELAYED HYPERSENSITIVITY IN THE GUINEA PIG BY 6-MERCAPTOPURINE

PubMed Central

Phillips, S. Michael; Zweiman, Burton

1973-01-01

The mechanism of suppression, of delayed hypersensitivity to tuberculoprotein by 6-mercaptopurine (6-MP) was studied in guinea pigs. Under the conditions of the protocol, suppression of tuberculin delayed skin test reactivity was not associated with a significantly altered end-organ response to mediators of permeability. No significant alteration of in vivo lymphoid activity, as measured by reconstitution studies, was found. In addition, lymphoid cells from 6-MP-treated animals reacted in a fashion similar to those of placebo-treated animals with respect to (a) antigen-induced lymphocyte proliferation, (b) antigen-induced liberation of macrophage inhibitory factor activity, (c) direct inhibition by antigen of peritoneal exudate cell migration. Conversely, suppression was seen in levels of blood monocytes and in vitro function of macrophages from 6-MP-treated animals in several respects: (a) adherence to glass, (b) migratory rate, (c) phagocytic capacity. Therefore, it would appear that a ma]or mechanism of 6-MP-induced suppression of delayed hypersensitivity is through its action on effector cells. PMID:4196793

High-speed scanning ablation of dental hard tissues with a λ = 9.3 μm CO2 laser: adhesion, mechanical strength, heat accumulation, and peripheral thermal damage

PubMed Central

Nguyen, Daniel; Chang, Kwang; Hedayatollahnajafi, Saba; Staninec, Michal; Chan, Kenneth; Lee, Robert; Fried, Daniel

2011-01-01

CO2 lasers can be operated at high laser pulse repetition rates for the rapid and precise removal of dental decay. Excessive heat accumulation and peripheral thermal damage is a concern when using high pulse repetition rates. Peripheral thermal damage can adversely impact the mechanical strength of the irradiated tissue, particularly for dentin, and reduce the adhesion characteristics of the modified surfaces. The interpulpal temperature rise was recorded using microthermocouples situated at the roof of the pulp chamber on teeth that were occlusally ablated using a rapidly-scanned CO2 laser operating at 9.3 μm with a pulse duration of 10 to 15 μs and repetition rate of 300 Hz over a 2 min time course. The adhesion strength of laser treated enamel and dentin surfaces was measured for various laser scanning parameters with and without post-ablation acid etching using the single-plane shear test. The mechanical strength of laser-ablated dentin surfaces were determined via the four-point bend test and compared to control samples prepared with 320 grit wet sand paper to simulate conventional preparations. Thermocouple measurements indicated that the temperature remained below ambient temperature if water-cooling was used. There was no discoloration of either dentin or enamel laser treated surfaces, the surfaces were uniformly ablated, and there were no cracks visible. Four-point bend tests yielded mean mechanical strengths of 18.2 N (s.d. = 4.6) for ablated dentin and 18.1 N (s.d. = 2.7) for control (p > 0.05). Shear tests yielded mean bond strengths approaching 30 MPa for both enamel and dentin under certain irradiation conditions. These values were slightly lower than nonirradiated acid-etched control samples. Additional studies are needed to determine if the slightly lower bond strength than the acid-etched control samples is clinically significant. These measurements demonstrate that enamel and dentin surfaces can be rapidly ablated by CO2 lasers with minimal peripheral thermal and mechanical damage and without excessive heat accumulation. PMID:21806256

High-speed scanning ablation of dental hard tissues with a λ = 9.3 μm CO2 laser: adhesion, mechanical strength, heat accumulation, and peripheral thermal damage

NASA Astrophysics Data System (ADS)

Nguyen, Daniel; Chang, Kwang; Hedayatollahnajafi, Saba; Staninec, Michal; Chan, Kenneth; Lee, Robert; Fried, Daniel

2011-07-01

CO2 lasers can be operated at high laser pulse repetition rates for the rapid and precise removal of dental decay. Excessive heat accumulation and peripheral thermal damage is a concern when using high pulse repetition rates. Peripheral thermal damage can adversely impact the mechanical strength of the irradiated tissue, particularly for dentin, and reduce the adhesion characteristics of the modified surfaces. The interpulpal temperature rise was recorded using microthermocouples situated at the roof of the pulp chamber on teeth that were occlusally ablated using a rapidly-scanned CO2 laser operating at 9.3 μm with a pulse duration of 10 to 15 μs and repetition rate of 300 Hz over a 2 min time course. The adhesion strength of laser treated enamel and dentin surfaces was measured for various laser scanning parameters with and without post-ablation acid etching using the single-plane shear test. The mechanical strength of laser-ablated dentin surfaces were determined via the four-point bend test and compared to control samples prepared with 320 grit wet sand paper to simulate conventional preparations. Thermocouple measurements indicated that the temperature remained below ambient temperature if water-cooling was used. There was no discoloration of either dentin or enamel laser treated surfaces, the surfaces were uniformly ablated, and there were no cracks visible. Four-point bend tests yielded mean mechanical strengths of 18.2 N (s.d. = 4.6) for ablated dentin and 18.1 N (s.d. = 2.7) for control (p > 0.05). Shear tests yielded mean bond strengths approaching 30 MPa for both enamel and dentin under certain irradiation conditions. These values were slightly lower than nonirradiated acid-etched control samples. Additional studies are needed to determine if the slightly lower bond strength than the acid-etched control samples is clinically significant. These measurements demonstrate that enamel and dentin surfaces can be rapidly ablated by CO2 lasers with minimal peripheral thermal and mechanical damage and without excessive heat accumulation.

High-speed scanning ablation of dental hard tissues with a λ = 9.3 μm CO2 laser: adhesion, mechanical strength, heat accumulation, and peripheral thermal damage.

PubMed

Nguyen, Daniel; Chang, Kwang; Hedayatollahnajafi, Saba; Staninec, Michal; Chan, Kenneth; Lee, Robert; Fried, Daniel

2011-07-01

CO(2) lasers can be operated at high laser pulse repetition rates for the rapid and precise removal of dental decay. Excessive heat accumulation and peripheral thermal damage is a concern when using high pulse repetition rates. Peripheral thermal damage can adversely impact the mechanical strength of the irradiated tissue, particularly for dentin, and reduce the adhesion characteristics of the modified surfaces. The interpulpal temperature rise was recorded using microthermocouples situated at the roof of the pulp chamber on teeth that were occlusally ablated using a rapidly-scanned CO(2) laser operating at 9.3 μm with a pulse duration of 10 to 15 μs and repetition rate of 300 Hz over a 2 min time course. The adhesion strength of laser treated enamel and dentin surfaces was measured for various laser scanning parameters with and without post-ablation acid etching using the single-plane shear test. The mechanical strength of laser-ablated dentin surfaces were determined via the four-point bend test and compared to control samples prepared with 320 grit wet sand paper to simulate conventional preparations. Thermocouple measurements indicated that the temperature remained below ambient temperature if water-cooling was used. There was no discoloration of either dentin or enamel laser treated surfaces, the surfaces were uniformly ablated, and there were no cracks visible. Four-point bend tests yielded mean mechanical strengths of 18.2 N (s.d. = 4.6) for ablated dentin and 18.1 N (s.d. = 2.7) for control (p > 0.05). Shear tests yielded mean bond strengths approaching 30 MPa for both enamel and dentin under certain irradiation conditions. These values were slightly lower than nonirradiated acid-etched control samples. Additional studies are needed to determine if the slightly lower bond strength than the acid-etched control samples is clinically significant. These measurements demonstrate that enamel and dentin surfaces can be rapidly ablated by CO(2) lasers with minimal peripheral thermal and mechanical damage and without excessive heat accumulation.

Chemical interaction of glycero-phosphate dimethacrylate (GPDM) with hydroxyapatite and dentin.

PubMed

Yoshihara, Kumiko; Nagaoka, Noriyuki; Hayakawa, Satoshi; Okihara, Takumi; Yoshida, Yasuhiro; Van Meerbeek, Bart

2018-04-28

Although the functional monomer glycero-phosphate dimethacrylate (GPDM) has since long been used in several dental adhesives and more recently in self-adhesive composite cements and restoratives, its mechanism of chemical adhesion to hydroxyapatite (HAp) is still unknown. We therefore investigated the chemical interaction of GPDM with HAp using diverse chemical analyzers and ultra-structurally characterized the interface of a GPDM-based primer formulation with dentin. HAp particles were added to a GPDM solution for various periods, upon which they were thoroughly washed with ethanol and water prior to being air-dried. As control, 10-methacryloyloxydecyl dihydrogen phosphate (MDP) was used. The molecular interaction of GPDM with HAp was analyzed using X-ray diffraction (XRD) and solid-state nuclear magnetic resonance (NMR) spectroscopy. Crystal formation upon application of GPDM onto dentin was analyzed using thin-film XRD (TF-XRD). Its hydrophobicity was measured using contact-angle measurement. The interaction of GPDM with dentin was characterized using transmission electron microscopy (TEM). XRD revealed the deposition of dicalcium phosphate dihydrate (DCPD: CaHPO 4 ·2H 2 O) on HAp after 24h. NMR confirmed the adsorption of GPDM onto HAp. However, GPDM was easily removed after washing with water, unlike MDP that remained adhered to HAp. Dentin treated with GPDM appeared more hydrophilic compared to dentin treated with MDP. TEM disclosed exposed collagen in the hybrid layer produced by the GPDM-based primer formulation. Although GPDM adsorbed to HAp, it did not form a stable calcium salt. The bond between GPDM and HAp was weak, unlike the strong bond formed by MDP to HAp. Due to its high hydrophilicity, GPDM might be an adequate monomer for an etch-and-rinse adhesive, but appears less appropriate for a 'mild' self-etch adhesive that besides micro-retention ionically interacts with HAp, or for a self-adhesive restorative material. Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

Use of a specific MMP inhibitor (Galardin) for preservation of hybrid layer

PubMed Central

Breschi, Lorenzo; Martin, Patrizia; Mazzoni, Annalisa; Nato, Fernando; Carrilho, Marcela; Tjäderhane, Leo; Visintini, Erika; Cadenaro, Milena; Tay, Franklin R; De Stefano Dorigo, Elettra; Pashley, David H

2013-01-01

Objective Dentinal MMPs have been claimed to contribute to the auto-degradation of collagen fibrils within incompletely resin-infiltrated hybrid layers and their inhibition may, therefore, slow the degradation of hybrid layer. This study aimed to determine the contribution of a synthetic MMPs inhibitor (Galardin) to the proteolytic activity of dentinal MMPs and to the morphological and mechanical features of hybrid layers after aging. Methods Dentin powder obtained from human molars was treated with Galardin or chlorhexidine digluconate and zymographically analyzed. Microtensile bond strength was also evaluated in extracted human teeth. Exposed dentin was etched with 35% phosphoric acid and specimens were assigned to (1) pre-treatment with Galardin as additional primer for 30s; (2) no pre-treatment. A two-step etch-and-rinse adhesive (Adper Scotchbond 1XT, 3M ESPE) was then applied in accordance with manufacturer's instructions and resin composite build-ups were created. Specimens were immediately tested for their microtensile bond strength or stored in artificial saliva for 12 months prior to being tested. Data were evaluated by two-way ANOVA and Tukey's tests (〈=0.05). Additional specimens were prepared for interfacial nanoleakage analysis under light microscopy and TEM, quantified by two independent observers and statistically analyzed (|2 test, 〈=0.05). Results The inhibitory effect of Galardin on dentinal MMPs was confirmed by zymographic analysis, as complete inhibition of both MMP-2 and -9 was observed. The use of Galardin had no effect on immediate bond strength, while it significantly decreased bond degradation after 1 year (p<0.05). Interfacial nanoleakage expression after aging revealed reduced silver deposits in galardin-treated specimens compared to controls (p<0.05). Conclusions This study confirmed that the proteolytic activity of dentinal MMPs was inhibited by the use of Galardin in a therapeutic primer. Galardin also partially preserved the mechanical integrity of the hybrid layer created by a two-step etch-and-rinse adhesive after artificial aging. PMID:20299089

Effect of dimethyl sulfoxide wet-bonding technique on hybrid layer quality and dentin bond strength.

PubMed

Stape, Thiago Henrique Scarabello; Tjäderhane, Leo; Marques, Marcelo Rocha; Aguiar, Flávio Henrique Baggio; Martins, Luís Roberto Marcondes

2015-06-01

This study examined the effect of a dimethyl sulfoxide (DMSO) wet bonding technique on the resin infiltration depths at the bonded interface and dentin bond strength of different adhesive systems. Flat dentin surfaces of 48 human third molars were treated with 50% DMSO (experimental groups) or with distilled water (controls) before bonding using an etch-and-rinse (SBMP: Scotchbond Multi-Purpose, 3M ESPE) or a self-etch (Clearfil: Clearfil SE Bond, Kuraray) adhesive system. The restored crown segments (n=12/group) were stored in distilled water (24h) and sectioned for interfacial analysis of exposed collagen using Masson's Trichrome staining and for microtensile bond strength testing. The extent of exposed collagen was measured using light microscopy and a histometric analysis software. Failure modes were examined by SEM. Data was analyzed by two-way ANOVA followed by Tukey Test (α=0.05). The interaction of bonding protocol and adhesive system had significant effects on the extension of exposed collagen matrix (p<0.0001) and bond strength (p=0.0091). DMSO-wet bonding significantly reduced the extent of exposed collagen matrix for SBMP and Clearfil (p<0.05). Significant increase in dentin bond strength was observed on DMSO-treated specimens bonded with SBMP (p<0.05), while no differences were observed for Clearfil (p>0.05). DMSO-wet bonding was effective to improve the quality of resin-dentin bonds of the tested etch-and-rinse adhesives by reducing the extent of exposed collagen matrix at the base of the resin-dentin biopolymer. The improved penetration of adhesive monomers is reflected as an increase in the immediate bond strength when the DMSO-wet bonding technique is used with a water-based etch-and-rinse adhesive. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Influence of dental restorations and mastication loadings on dentine fatigue behaviour: Image-based modelling approach.

PubMed

Vukicevic, Arso M; Zelic, Ksenija; Jovicic, Gordana; Djuric, Marija; Filipovic, Nenad

2015-05-01

The aim of this study was to use Finite Element Analysis (FEA) to estimate the influence of various mastication loads and different tooth treatments (composite restoration and endodontic treatment) on dentine fatigue. The analysis of fatigue behaviour of human dentine in intact and composite restored teeth with root-canal-treatment using FEA and fatigue theory was performed. Dentine fatigue behaviour was analysed in three virtual models: intact, composite-restored and endodontically-treated tooth. Volumetric change during the polymerization of composite was modelled by thermal expansion in a heat transfer analysis. Low and high shrinkage stresses were obtained by varying the linear shrinkage of composite. Mastication forces were applied occlusally with the load of 100, 150 and 200N. Assuming one million cycles, Fatigue Failure Index (FFI) was determined using Goodman's criterion while residual fatigue lifetime assessment was performed using Paris-power law. The analysis of the Goodman diagram gave both maximal allowed crack size and maximal number of cycles for the given stress ratio. The size of cracks was measured on virtual models. For the given conditions, fatigue-failure is not likely to happen neither in the intact tooth nor in treated teeth with low shrinkage stress. In the cases of high shrinkage stress, crack length was much larger than the maximal allowed crack and failure occurred with 150 and 200N loads. The maximal allowed crack size was slightly lower in the tooth with root canal treatment which induced somewhat higher FFI than in the case of tooth with only composite restoration. Main factors that lead to dentine fatigue are levels of occlusal load and polymerization stress. However, root canal treatment has small influence on dentine fatigue. The methodology proposed in this study provides a new insight into the fatigue behaviour of teeth after dental treatments. Furthermore, it estimates maximal allowed crack size and maximal number of cycles for a specific case. Copyright © 2015 Elsevier Ltd. All rights reserved.

EFFECT OF AN ADDITIONAL HYDROPHILIC VERSUS HYDROPHOBIC COAT ON THE QUALITY OF DENTINAL SEALING PROVIDED BY TWO-STEP ETCH-AND-RINSE ADHESIVES

PubMed Central

Silva, Safira Marques de Andrade; Carrilho, Marcela Rocha de Oliveira; Marquezini, Luiz; Garcia, Fernanda Cristina Pimentel; Manso, Adriana Pigozzo; Alves, Marcelo Corrêa; de Carvalho, Ricardo Marins

2009-01-01

Objective: To test the hypothesis that the quality of the dentinal sealing provided by two-step etch-and-rinse adhesives cannot be altered by the addition of an extra layer of the respective adhesive or the application of a more hydrophobic, non-solvated resin. Material and Methods: full-crown preparations were acid-etched with phosphoric acid for 15 s and bonded with Adper Single Bond (3M ESPE), Excite DSC (Ivoclar/Vivadent) or Prime & Bond NT (Dentsply). The adhesives were used according to the manufacturers' instructions (control groups) or after application to dentin they were a) covered with an extra coat of each respective system or b) coated with a non-solvated bonding agent (Adper Scotchbond Multi-Purpose Adhesive, 3M ESPE). Fluid flow rate was measured before and after dentin surfaces were acid-etched and bonded with adhesives. Results: None of the adhesives or experimental treatments was capable to block completely the fluid transudation across the treated dentin. Application of an extra coat of the adhesive did not reduce the fluid flow rate of adhesive-bonded dentin (p>0.05). Conversely, the application of a more hydrophobic non-solvated resin resulted in significant reductions in the fluid flow rate (p<0.05) for all tested adhesives. Conclusions: The quality of the dentinal sealing provided by etch-and-rinse adhesives can be significantly improved by the application of a more hydrophobic, non-solvated bonding agent. PMID:19466248

Reflux Hypersensitivity: A New Functional Esophageal Disorder

PubMed Central

Yamasaki, Takahisa; Fass, Ronnie

2017-01-01

Reflux hypersensitivity, recently introduced by Rome IV as a new functional esophageal disorder, is currently considered as the presence of typical heartburn symptoms in patients with normal upper endoscopy and esophageal biopsies, normal esophageal pH test and with evidence of a close correlation between patients’ heartburn and reflux events. Reflux hypersensitivity is very common and together with functional heartburn accounts for more than 90% of the heartburn patients who failed treatment with proton pump inhibitor twice daily. In addition, reflux hypersensitivity affects primarily young to middle aged women, commonly overlaps with another functional gastrointestinal disorders, and is often associated with some type of psychological comorbidity. Diagnosis is made by using endoscopy with esophageal biopsies, pH-impedance, and high-resolution esophageal manometry. Reflux hypersensitivity is primarily treated with esophageal neuromodulators, such as tricyclic anti-depressants and selective serotonin reuptake inhibitors among others. Surgical anti-reflux management may also play an important role in the treatment of reflux hypersensitivity. PMID:28992673

Nanotechnology in Dentistry: Clinical Applications, Benefits, and Hazards.

PubMed

Shashirekha, Govind; Jena, Amit; Mohapatra, Satyajit

2017-05-01

Nanotechnology is emerging as an interdisciplinary field that is undergoing rapid development and has brought about enormous changes in medicine and dentistry. Nanomaterial-based design is able to mimic some of the mechanical and structural properties of native tissue and can promote biointegration. Nanotechnology has various applications in dentistry, including dentition renaturalization, therapy for dentin hypersensitivity, complete orthodontic realignment in a single visit, covalently bonding diamondized enamel, enhancing properties of root canal sealers, and continuous oral health maintenance using mechanical dentifrobots. A range of synthetic nanoparticles such as hydroxyapatite, bioglass, titanium, zirconia, and silver nanoparticles are proposed for dental restoration. This review focuses on the developments in the field of nanomaterials in dentistry in the form of tissue regeneration materials, implantable devices, nanocomposites, endodontic sealers etc. and issues of patient safety.

Pain and anxiety control: an online study guide.

PubMed

2008-05-01

The Editorial Board of the Journal of Endodontics has developed a literature-based study guide of topical areas related to endodontics. This study guide is intended to give the reader a focused review of the essential endodontic literature and does not cite all possible articles related to each topic. Although citing all articles would be comprehensive, it would defeat the idea of a study guide. This section will cover pain theories and dentin hypersensitivity, referred pain, oral pain not of dental origin, barodontalgia, local anesthetics, long-acting local anesthetics, intrapulpal anesthesia, intraligamentary anesthesia, intraosseous anesthesia, inferior alveolar nerve block anesthesia, Gow-Gates anesthesia technique, Vazirani-Akinosi anesthesia technique, second-division block anesthesia technique, endodontic postoperative pain, effect of occlusal adjustment on endodontic pain, paresthesia associated with periradicular pathosis, analgesics, sedation, and endodontic flare-ups.

Laser in dentistry: An innovative tool in modern dental practice

PubMed Central

Verma, Sanjeev Kumar; Maheshwari, Sandhya; Singh, Raj Kumar; Chaudhari, Prabhat Kumar

2012-01-01

The term LASER is an acronym for ‘Light Amplification by the Stimulated Emission of Radiation’. As its first application in dentistry by Miaman, in 1960, the laser has seen various hard and soft tissue applications. In the last two decades, there has been an explosion of research studies in laser application. In hard tissue application, the laser is used for caries prevention, bleaching, restorative removal and curing, cavity preparation, dentinal hypersensitivity, growth modulation and for diagnostic purposes, whereas soft tissue application includes wound healing, removal of hyperplastic tissue to uncovering of impacted or partially erupted tooth, photodynamic therapy for malignancies, photostimulation of herpetic lesion. Use of the laser proved to be an effective tool to increase efficiency, specificity, ease, and cost and comfort of the dental treatment. PMID:23833485

Temperature rises during application of Er:YAG laser under different primary dentin thicknesses.

PubMed

Hubbezoglu, Ihsan; Unal, Murat; Zan, Recai; Hurmuzlu, Feridun

2013-05-01

The present study investigated the effects of the Er:YAG laser's different pulse repetition rates on temperature rise under various primary dentin thicknesses. The Er:YAG laser can be used for restorative approaches in clinics and is used to treat dental caries. There are some reports that explain the temperature rise effect of the Er:YAG laser. Recently, the Er:YAG laser has been found to play an important role in temperature rises during the application on dentin. Caries-free primary mandibular molars were prepared to obtain dentin discs with 0.5, 1, 1.5, and 2 mm thicknesses (n=10). These discs were placed between the Teflon mold cylinders of a temperature test apparatus. We preferred three pulse repetition rates of 10, 15, and 20 Hz with an energy density of 12.7 J/cm2 and a 230 μs pulse duration. All dentin discs were irradiated for 30 sec by the Er:YAG laser. Temperature rises were recorded using an L-type thermocouple and universal data loggers/scanners (E-680, Elimko Co., Turkey). Data were analyzed by two-way ANOVA and Tukey tests. Whereas the lowest temperature rise (0.44±0.09 °C) was measured from a 10 Hz pulse repetition rate at a dentin thickness of 2 mm, the highest temperature rise (3.86±0.43 °C) was measured from a 20 Hz pulse repetition rate at a 0.5 mm dentin thickness. Temperature rise did not reach critical value for pulpal injury in any primary dentin thicknesses irradiated by a high repetition rate of the Er:YAG laser.

Dentin bond optimization using the dimethyl sulfoxide-wet bonding strategy: A 2-year in vitro study.

PubMed

Stape, Thiago Henrique Scarabello; Tjäderhane, Leo; Tezvergil-Mutluay, Arzu; Yanikian, Cristiane Rumi Fujiwara; Szesz, Anna Luiza; Loguercio, Alessandro Dourado; Martins, Luís Roberto Marcondes

2016-12-01

This study evaluated a new approach, named dimethyl sulfoxide (DMSO)-wet bonding, to produce more desirable long-term prospects for the ultrafine interactions between synthetic polymeric biomaterials and the inherently hydrated dentin substrate. Sound third molars were randomly restored with/without DMSO pretreatment using a total-etch (Scocthbond Multipurpose: SBMP) and a self-etch (Clearfil SE Bond: CF) adhesive systems. Restored teeth (n=10)/group were sectioned into sticks and submitted to different analyses: micro-Raman determined the degree of conversion inside the hybrid layer (DC); resin-dentin microtensile bond strength and fracture pattern analysis at 24h, 1year and 2 years of aging; and nanoleakage evaluation at 24h and 2 years. DMSO-wet bonding produced significantly higher 24h bond strengths for SBMP that were sustained over the two-year period, with significantly less adhesive failures. Similarly, DMSO-treated CF samples presented significantly higher bond strength than untreated samples at two years. Both adhesives had significant less adhesive failures at 2 years with DMSO. DMSO had no effect on DC of SBMP, but significantly increased the DC of CF. DMSO-treated SBMP samples presented reduced silver uptake compared to untreated samples after aging. Biomodification of the dentin substrate by the proposed strategy using DMSO is a suitable approach to produce more durable hybrid layers with superior ability to withstand hydrolytic degradation over time. Although the active role of DMSO on dentin bond improvement may vary according to monomer composition, its use seems to be effective on both self-etch and etch-and-rinse bonding mechanisms. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Lateral and axial cutting efficiency of instruments manufactured with conventional nickel-titanium and novel gold metallurgy.

PubMed

Vasconcelos, R A; Arias, A; Peters, O A

2018-05-01

To isolate the effect of metallurgy in lateral and axial cutting efficacy against plastic and bovine dentine substrates by comparing two rotary systems with identical design but manufactured with either conventional nickel-titanium or heat-treated gold alloy. A total of 258 ProTaper Universal (PTU) and ProTaper Gold (PTG) Shaping instruments were used. Bending behaviour was assessed to determine the appropriate displacement associated with a 2 N force in lateral cutting. Ten instruments of each type were used in lateral action for 60 s against bovine dentine or plastic substrates four consecutive times producing four notches in each specimen. Ten further instruments of each type were used in on axial action in four standardized simulated root canals fabricated from 4-mm thick plastic or dentine discs. Both tests were performed at 300 rpm in a computer-controlled testing platform. Notch area and torsional load were compared with Student's t-tests. Repeated measures ANOVA was used to compare cutting efficiency across the four different time-points. Pearson correlation coefficients between substrates were also determined. For lateral action, all three PTG instruments cut significantly more effectively (P < 0.05) than PTU on the plastic substrate. S1 and S2 PTG cut significantly more after 120 and 180 s (P < 0.05) on bovine dentine substrate. For axial action, S1 and S2 PTG were significantly more efficient in cutting at 180 s on plastic and 120 s on bovine dentine (P < 0.05). Instruments made from heat-treated nickel-titanium gold alloy had equal or greater cutting efficiency when compared to those made from conventional nickel-titanium. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Role of LIGHT in the pathogenesis of joint destruction in rheumatoid arthritis

PubMed Central

Sabokbar, Afsie; Afrough, Sara; Mahoney, David J; Uchihara, Yoshinobu; Swales, Catherine; Athanasou, Nicholas A

2017-01-01

AIM To characterise the role of substitutes for receptor-activator nuclear factor kappa-B ligand (RANKL) in rheumatoid arthritis (RA) joint destruction. METHODS Synovial fluid (SF) macrophages isolated from the knee joint of RA patients were incubated with 25 ng/mL macrophage-colony stimulating factor (M-CSF) and 50 ng/mL LIGHT (lymphotoxin-like, exhibits inducible expression and competes with herpes simplex virus glycoprotein D for herpes virus entry mediator, a receptor expressed by T lymphocytes) in the presence and absence of 25 ng/mL RANKL and 100 ng/mL osteoprotegerin (OPG) on glass coverslips and dentine slices. Osteoclastogenesis was assessed by the formation of multinucleated cells (MNCs) expressing tartrate-resistant acid phosphatase (TRAP) on coverslips and the extent of lacunar resorption pit formation on dentine slices. The concentration of LIGHT in RA and osteoarthritis (OA) synovial fluid was measured by an enzyme-linked immunosorbent assay (ELISA) and the expression of LIGHT in RA and OA synovium was determined by immunohistochemistry using an indirect immunoperoxidase technique. RESULTS In cultures of RA SF macrophages treated with LIGHT and M-CSF, there was significant formation of TRAP + MNCs on coverslips and extensive lacunar resorption pit formation on dentine slices. SF-macrophage-osteoclast differentiation was not inhibited by the addition of OPG, a decoy receptor for RANKL. Resorption pits were smaller and less confluent than in RANKL-treated cultures but the overall percentage area of the dentine slice resorbed was comparable in LIGHT- and RANKL-treated cultures. LIGHT significantly stimulated RANKL-induced lacunar resorption compared with RA SF macrophages treated with either RANKL or LIGHT alone. LIGHT was strongly expressed by synovial lining cells, subintimal macrophages and endothelial cells in RA synovium and the concentration of LIGHT was much higher in RA compared with OA SF. CONCLUSION LIGHT is highly expressed in RA synovium and SF, stimulates RANKL-independent/dependent osteoclastogenesis from SF macrophages and may contribute to marginal erosion formation. PMID:28589079

Dentin bonding performance and interface observation of an MMA-based restorative material.

PubMed

Shinagawa, Junichi; Inoue, Go; Nikaido, Toru; Ikeda, Masaomi; Sadr, Alireza; Tagami, Junji

2016-07-30

The purpose of this study was to evaluate bonding performance and dentin interface acid resistance using a 4-META/MMA-TBB based restorative material (BF) compared to a conventional 4-META/MMA-TBB resin cement (SB), and the effect of sodium fluoride (NaF) addition to the materials. Dentin surfaces were treated with 10% citric acid-3% ferric chloride (10-3) or 4-META containing self-etching primer (TP), followed by application of BF or SB polymer powders with or without NaF, to evaluate microtensile bond strength (µTBS) in six experimental groups; 10-3/SB, 10-3/BF, TP/SB, TP/BF, TP/SB/NaF and TP/BF/NaF. SEM observation of the resin-dentin interface was performed after acid-base challenge to evaluate interfacial dentin resistance to acid attack. TP/BF showed highest µTBS, while NaF polymers decreased µTBS. TP/BF showed funnel-shaped erosion at the interface, however, NaF polymers improved acid resistance of interface. In conclusion, BF demonstrated high µTBSs and low acid-resistance at the interface. NaF addition enhanced acid resistance but decreased µTBS.

Effect of Instrumentation Techniques, Irrigant Solutions and Artificial accelerated Aging on Fiberglass Post Bond Strength to Intraradicular Dentin.

PubMed

Santana, Fernanda Ribeiro; Soares, Carlos José; Silva, Júlio Almeida; Alencar, Ana Helena Gonçalves; Renovato, Sara Rodrigues; Lopes, Lawrence Gonzaga; Estrela, Carlos

2015-07-01

To evaluate the effect of instrumentation techniques, irrigant solutions and specimen aging on fiberglass posts bond strength to intraradicular dentine. A total of 120 bovine teeth were prepared and randomized into control and experimental groups resulting from three study factors (instrumentation techniques, irrigant solutions, specimen aging). Posts were cemented with RelyX U100. Samples were submitted to push-out test and failure mode was evaluated under a confocal microscope. In specimens submitted to water artificial aging, nickel-titanium rotary instruments group presented higher bond strength values in apical third irrigated with NaOCl or chlorhexi-dine. Irrigation with NaOCl resulted in higher bond strength than ozonated water. Artificial aging resulted in significant bond strength increase. Adhesive cement-dentin failure was prevalent in all the groups. Root canal preparation with NiTi instruments associated with NaOCl irrigation and ethylenediaminetetra acetic acid (EDTA) increased bond strength of fiberglass posts cemented with self-adhesive resin cement to intraradicular dentine. Water artificial aging significantly increased post-Clinical significance: The understanding of factors that may influence the optimal bond between post-cement and cement-dentin are essential to the success of endodontically treated tooth restoration.

Application of x-ray nano-particulate markers for the visualization of intermediate layers and interfaces using scanning electron microscopy

NASA Astrophysics Data System (ADS)

Bessudnova, Nadezda O.; Bilenko, David I.; Zakharevich, Andrey M.

2012-03-01

In this study the methodology of biological sample preparation for dental research using SEM/EDX has been elaborated. (1)The original cutting equipment supplied with 3D user-controlled sample fixation and an adjustable cooling system has been designed and evaluated. (2) A new approach to the root dentine drying procedure has been developed to preserve structure peculiarities of root dentine. (3) A novel adhesive system with embedded X-Ray nanoparticulate markers has been designed. (4)The technique allowing for visualization of bonding resins, interfaces and intermediate layers between tooth hard tissues and restorative materials of endodontically treated teeth using the X-ray nano-particulate markers has been developed and approved. These methods and approaches were used to compare the objective depth of penetration of adhesive systems of different generations in root dentine. It has been shown that the depth of penetration in dentine is less for adhesive systems of generation VI in comparison with bonding resins of generation V, which is in agreement with theoretical evidence. The depth of penetration depends on the correlation between the direction of dentinal tubules, bonding resin delivery and gravity.

Aspirin Allergy Desensitization in Cerebrovascular Disease

PubMed Central

Zuckerman, Scott L; Seder, David B; Tsujiura, Crystiana; Cushing, Deborah; Gallup, Holly; Mocco, J; Hanel, Richard A; Ecker, Robert D

2014-01-01

Summary Aspirin (ASA) is the mainstay of treatment in cerebrovascular and systemic vascular disease. ASA hypersensitivity can pose a challenge to achieving optimum medical management prior to and after neurointerventional treatment. Desensitization to ASA is well described in the allergy and cardiovascular literature, but there are no similar discussions specific to neurointervention. The purpose of our study was to describe our experience with ASA hypersensitivity management and review the relevant literature. Two cases of patients with symptomatic cerebrovascular disease requiring neurointervention who were successfully desensitized to their ASA hypersensitivity prior to treatment are described. The subsequent literature is reviewed. Several ASA desensitization protocols exist and have been proven to successfully treat ASA hypersensitivity and allow for ASA therapy to be safely initiated. We describe several previously published protocols. ASA desensitization is a safe and simple way to manage ASA hypersensitivity. We provide comprehensive management guidelines for the neurointerventionalist engaging in ASA desensitization. PMID:24556294

Long-term survival and vitality outcomes of permanent teeth following deep caries treatment with step-wise and partial-caries-removal: A Systematic Review.

PubMed

Hoefler, Vaughan; Nagaoka, Hiroko; Miller, Craig S

2016-11-01

A systematic review was performed to compare the long-term survival of deep dentine caries-affected permanent teeth treated with partial-caries-removal (PCR) versus similar teeth treated with stepwise-caries-removal techniques (SWT). Clinical studies investigating long-term PCR and SWT outcomes in unrestored permanent teeth with deep dentine caries were evaluated. Failures were defined as loss of pulp vitality or restorative failures following treatment. PubMed, Web of Science, Dentistry and Oral Sciences Source, and Central databases were systematically searched. From 136 potentially relevant articles, 9 publications utilizing data from 5 studies (2 RCTs, and 3 observational case-series) reporting outcomes for 426 permanent teeth over two to ten years were analyzed. Regarding restorative failures, >88% success at two years for both techniques was reported. For loss of pulp vitality, observational studies reported >96% vitality at two years for each technique, while one RCT reported significantly higher vitality (p<0.05) at three years for PCR (96%) compared to SWT (83%). Risk of bias was high in all studies. Successful vitality and restorative outcomes for both PCR and SWT have been demonstrated at two years and beyond in permanent teeth with deep dentine caries. Partial-caries-removal may result in fewer pulpal complications over a three year period than SWT, although claims of a therapeutic advantage are based on very few, limited-quality studies. Partial-caries-removal and SWT are deep caries management techniques that reduce pulp exposure risk. Permanent teeth with deep dentine caries treated with either technique have a high likelihood for survival beyond two years. Copyright © 2016 Elsevier Ltd. All rights reserved.

The effect of zoledronate-containing primer on dentin bonding of a universal adhesive.

PubMed

Zenobi, Walter; Feitosa, Victor Pinheiro; Moura, Maria Elisa Martins; D'arcangelo, Camillo; Rodrigues, Lidiany Karla de Azevedo; Sauro, Salvatore

2018-01-01

To evaluate the bonding ability and nanoleakage of a universal adhesive applied to dentin pre-treated using a zoledronate-containing primer (zol-primer) before and after mechanical load cycling. Flat dentin surfaces obtained from human molars were assigned to one of the following adhesion procedures (n=6): 1-Single Bond Universal (SBU) applied in etch-and-rinse mode; 2- SBU applied as etch-and-rinse after the application of zol-primer; 3- SBU applied in self-etch strategy; 4- SBU applied as self-etch after the use of zol-primer. Half of the specimens were processed for microtensile bond strength test after 24h, while the other half part was submitted to 200,000 mechanical cycles. Further specimens were silver-impregnated and assessed for interface nanoleakage by SEM. Data were analyzed with two-way ANOVA and Tukey's test (p<0.05). At 24h evaluation, the four groups presented similar bond strengths, whilst both groups bonded with etch-and-rinse technique showed significant bond strength reduction after mechanical load (p<0.05), with the highest drop in bond strength for the specimens pre-treated with the zol-primer. No negative effects were found for self-etch strategy (p>0.05) in microtensile test. Lower nanoleakage expression was observed for etch-and-rinse specimens treated with zol-primer. However, noteworthy reduction of adhesive layer thickness was observed when combining the zol-primer with the self-etch bonding approach. It can be concluded that zol-primer should not be used along with a universal adhesive in etch-and-rinse mode, but its application before self-etch application may provide less degradation of the resin-dentin interface. Copyright © 2017 Elsevier Ltd. All rights reserved.

Drosophila Insulin receptor regulates the persistence of injury-induced nociceptive sensitization

PubMed Central

Patel, Atit A.

2018-01-01

ABSTRACT Diabetes-associated nociceptive hypersensitivity affects diabetic patients with hard-to-treat chronic pain. Because multiple tissues are affected by systemic alterations in insulin signaling, the functional locus of insulin signaling in diabetes-associated hypersensitivity remains obscure. Here, we used Drosophila nociception/nociceptive sensitization assays to investigate the role of Insulin receptor (Insulin-like receptor, InR) in nociceptive hypersensitivity. InR mutant larvae exhibited mostly normal baseline thermal nociception (absence of injury) and normal acute thermal hypersensitivity following UV-induced injury. However, their acute thermal hypersensitivity persists and fails to return to baseline, unlike in controls. Remarkably, injury-induced persistent hypersensitivity is also observed in larvae that exhibit either type 1 or type 2 diabetes. Cell type-specific genetic analysis indicates that InR function is required in multidendritic sensory neurons including nociceptive class IV neurons. In these same nociceptive sensory neurons, only modest changes in dendritic morphology were observed in the InRRNAi-expressing and diabetic larvae. At the cellular level, InR-deficient nociceptive sensory neurons show elevated calcium responses after injury. Sensory neuron-specific expression of InR rescues the persistent thermal hypersensitivity of InR mutants and constitutive activation of InR in sensory neurons ameliorates the hypersensitivity observed with a type 2-like diabetic state. Our results suggest that a sensory neuron-specific function of InR regulates the persistence of injury-associated hypersensitivity. It is likely that this new system will be an informative genetically tractable model of diabetes-associated hypersensitivity. PMID:29752280

Effect of EDTA, sodium hypochlorite, and chlorhexidine gluconate with or without surface modifiers on dentin microhardness.

PubMed

Aslantas, Eda E; Buzoglu, Hatice Dogan; Altundasar, Emre; Serper, Ahmet

2014-06-01

This study aimed to evaluate the effects of root canal irrigants on the microhardness of root canal dentin in the presence and absence of surface-modifying agents. Forty-eight root halves were prepared by longitudinal splitting of the distal roots of 24 freshly extracted mandibular human third molars and embedded in autopolymerizing acrylic resin, leaving the dentin surface exposed. After polishing, the microhardness values of the untreated dentin surfaces were recorded by using Vickers tester at the mid-root level. The root halves were randomly assigned to 6 groups composed of 8 samples each and treated for 5 minutes with one of the following irrigants: 17% EDTA, REDTA, 2% chlorhexidine gluconate (CHX), 2% CHX with surface modifiers (CHX-Plus), 6% NaOCl, or 6% NaOCl with surface modifiers (Chlor-XTRA). After surface treatment, dentin microhardness values were recorded at close proximity to the initial indentation areas. Experimental data were statistically analyzed by using the t test and one-way analysis of variance, followed by Tukey honestly significant difference test at α = 0.05. EDTA, REDTA, NaOCl, and Chlor-XTRA significantly decreased the microhardness of root dentin compared with intact controls (P < .05). The addition of surface modifiers to the irrigants did not affect the microhardness of the samples. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Evaluation of caries progression in dentin treated by fluoride-containing materials using an in-air micro-PIGE and micro-PIXE measurement system

NASA Astrophysics Data System (ADS)

Yamamoto, H.; Iwami, Y.; Yagi, K.; Hayashi, M.; Komatsu, H.; Okuyama, K.; Matsuda, Y.; Yasuda, K.

2015-04-01

It is well-known that fluorine (F) is involved in the progression of caries. The evaluation of caries progression has conventionally been based on the change in mineral content using transverse microradiography (TMR). The purpose of this study was to evaluate the progression of dentinal caries by the change in calcium (Ca) content using Particle-Induced Gamma-ray Emission/Particle-Induced X-ray Emission (PIGE/PIXE) techniques at the Wakasa Wan Energy Research Center. We also assessed the relationship between caries progression rate and the concentration of F penetration into dentin from dental fluoride-containing materials (FCMs). Dentin sections of six extracted human teeth were prepared to obtain various amounts of F uptake using three types of FCMs. F and Ca distribution of specimens were obtained using PIGE/PIXE techniques. After evaluation, the specimens were immersed in 10 ml of demineralizing solution (pH 4.5) to simulate caries attack. To estimate caries progression rates, the same portions of the specimens were evaluated after caries attack treatment using PIGE/PIXE. A negative correlation between the F uptake in dentin and the rate of caries progression was observed. Therefore, caries progression in dentin was reduced by increasing the amount of F uptake from FCMs. This demonstrates that PIGE/PIXE techniques are valuable for estimating caries progression rates.

Effect of Collagen Matrix Saturation on the Surface Free Energy of Dentin using Different Agents.

PubMed

de Almeida, Leopoldina de Fátima Dantas; Souza, Samilly Evangelista; Sampaio, Aline Araújo; Cavalcanti, Yuri Wanderley; da Silva, Wander José; Del Bel Cur, Altair A; Hebling, Josimeri

2015-07-01

The surface free energy of conditioned-dentin is one of the factors that interfere with monomeric infiltration of the interfibrillar spaces. Saturation of the tooth matrix with different substances may modulate this energy and, consequently, the wettability of the dentin. To evaluate the influence of different substances used to saturate conditioned-dentin on surface free energy (SFE) of this substrate. Dentin blocks (4 × 7 × 1 mm, n = 6/ group), obtained from the roots of bovine incisors, were etched using phosphoric acid for 15 seconds, rinsed and gently dried. The surfaces were treated for 60 seconds with: ultra-purified water (H20-control); ethanol (EtOH), acetone (ACT), chlorhexidine (CHX), ethylenediaminetetraacetic acid (EDTA); or sodium hypochlorite (NaOCl). The tooth surfaces were once again dried with absorbent paper and prepared for SFE evaluation using three standards: water, formamide and bromonaphthalene. Analysis of variance (ANOVA) and Dunnet's tests (a = 0.05) were applied to the data. Ethylenediaminetetraacetic acid was the only substance that caused a change to the contact angle for the standards water and formamide, while only EtOH influenced the angles formed between formamide and the dentin surface. None of the substances exerted a significant effect for bromonaphtha-lene. In comparison to the control, only EDTA and NaOCl altered both polar components of the SFE. Total SFE was increased by saturation of the collagen matrix by EDTA and reduced when NaOCl was used. Saturation of the collagen matrix by EDTA and EtOH changed the surface free energy of the dentin. In addition, the use of NaOCl negatively interfered with the properties evaluated. The increase of surface free energy and wettability of the dentin surface would allow higher penetration of the the adhesive system, which would be of importance to the clinical success of resin-dentin union.

Alteration of Dentin-Enamel Mechanical Properties Due to Dental Whitening Treatments

PubMed Central

Zimmerman, B.; Datko, L.; Cupelli, M.; Alapati, S.; Dean, D.; Kennedy, M.

2010-01-01

The mechanical properties of dentin and enamel affect the reliability and wear properties of a tooth. This study investigated the influence of clinical dental treatments and procedures, such as whitening treatments or etching prior to restorative procedures. Both autoclaved and non-autoclaved teeth were studied in order to allow for both comparison with published values and improved clinical relevance. Nanoindentation analysis with the Oliver-Pharr model provided elastic modulus and hardness across the dentin-enamel junction (DEJ). Large increases were observed in the elastic modulus of enamel in teeth that had been autoclaved (52.0GPa versus 113.4GPa), while smaller increases were observed in the dentin (17.9GPa versus 27.9GPa). Likewise, there was an increase in the hardness of enamel (2.0GPa versus 4.3GPa) and dentin (0.5GPa versus 0.7GPa) with autoclaving. These changes suggested that the range of elastic modulus and hardness values previously reported in literature may be partially due to the sterilization procedures. Treatment of the exterior of non-autoclaved teeth with Crest Whitestrips™, Opalescence™ or UltraEtch™ caused changes in the mechanical properties of both the enamel and dentin. Those treated with Crest Whitestrips™ showed a reduction in the elastic modulus of enamel (55.3GPa to 32.7GPa) and increase in the elastic modulus of dentin (17.2GPa to 24.3GPa). Opalescence™ treatments did not significantly affect the enamel properties, but did result in a decrease in modulus of dentin (18.5GPa to 15.1GPa). Additionally, as expected, UltraEtch™ treatment decreased the modulus and hardness of enamel (48.7GPa to 38.0GPa and 1.9GPa to 1.5GPa, respectively) and dentin (21.4GPa to 15.0GPa and 1.9GPa to 1.5GPa, respectively). Changes in the mechanical properties were linked to altered protein concentration within the tooth, as evidenced by fluorescence microscopy and Fourier transform infrared spectroscopy. PMID:20346902

Characterization of Chlorhexidine-Loaded Calcium-Hydroxide Microparticles as a Potential Dental Pulp-Capping Material.

PubMed

Priyadarshini, Balasankar M; Selvan, Subramanian T; Narayanan, Karthikeyan; Fawzy, Amr S

2017-06-22

This study explores the delivery of novel calcium hydroxide [Ca(OH)₂] microparticles loaded with chlorhexidine (CHX) for potential dental therapeutic and preventive applications. Herein, we introduce a new approach for drug-delivery to deep dentin-surfaces in the form of drug-loaded microparticles. Unloaded Ca(OH)₂ [Ca(OH)₂/Blank] and CHX-loaded/Ca(OH)₂ microparticles were fabricated by aqueous chemical-precipitation technique. The synthesized-microparticles were characterized in vitro for determination of surface-morphology, crystalline-features and thermal-properties examined by energy-dispersive X-ray scanning and transmission electron-microscopy (EDX-SEM/TEM), Fourier-transform infrared-spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential scanning-calorimetry (DSC). Time-related pH changes, initial antibacterial/biofilm-abilities and cytotoxicity of CHX-loaded/Ca(OH)₂ microparticles were evaluated. Microparticles were delivered to dentin-surfaces with subsequent SEM examination of treated dentin-substrates. The in vitro and ex vivo CHX-release profiles were characterized. Ca(OH)₂/Blank were hexagonal-shaped with highest z -average diameter whereas CHX-inclusion evidenced micro-metric spheres with distinguishable surface "rounded deposits" and a negative-shift in diameter. CHX:Ca(OH)₂/50 mg exhibited maximum encapsulation-efficiency with good antibacterial and cytocompatible properties. SEM examination revealed an intact layer of microparticles on exposed dentin-surfaces with retention of spherical shape and smooth texture. Microparticles loaded on dentin-surfaces showed prolonged release of CHX indicating substantial retention on dentin-substrates. This study validated the inherent-applicability of this novel drug-delivery approach to dentin-surfaces using micro-metric CHX-loaded/Ca(OH)₂ microparticles.

Effects of Contamination by Hemostatic Agents and Use of Cleaning Agent on Etch-and-Rinse Dentin Bond Strength.

PubMed

Pucci, César Rogério; Araújo, Rodrigo Maximo de; Lacerda, Ana Julia Farias de; Souza, Mirella Anjos de; Huhtala, Maria Filomena Rocha Lima; Feitosa, Fernanda Alves

2016-01-01

The aim of this study was to evaluate the influence of contamination by hemostatic agents and rinsing with chlorhexidine on bond strength between dentin and resin composite. Ninety-six bovine teeth were sectioned to expose a flat dentin surface area. A standardized cavity with 2.0 mm in thickness, superficial diameter of 4.0 mm and bottom diameter of 3.0 mm was prepared with a diamond bur in each dentin specimen. The teeth were divided into four groups according to the hemostatic employed: G1: control; G2: use of ViscoStat, Ultradent; G3: Hemosthasegel, FGM; and G4: Hemostop, Dentsply. The groups were divided into two subgroups according to the cleaning protocol method (n=12): A: without any further cleaning; and B: cleaning with chlorhexidine at 0.2%. All cavities were filled using a dentin adhesive and a resin composite, following the manufacturer's instructions. After 24 h, the specimens were aged by thermal and mechanical cycling. The bond strength was determined by the push out bond test (MPa), Statistical analysis was performed using two-way ANOVA and Tukey test (p<0.05). Statistically significant differences were detected among all groups treated with hemostatic agents and the control group. The post-hoc test showed that cleaning the cavity with chlorhexidine significantly improves the bond strength between dentin and resin composite. Our results suggested that the use of chlorhexidine can reestablish the bond strength between dentin and resin composite when a hemostatic agent was applied.

Anacardic acid from brazilian cashew nut trees reduces dentine erosion.

PubMed

Silveira, Cintia; Oliveira, Flávia; Dos Santos, Maria Lucilia; de Freitas, Thiago; Imparato, José Carlos; Magalhães, Ana Carolina

2014-01-01

The aim of this study was to analyze the effect of solutions containing saturated anacardic acid (AA) on dentine erosion in vitro. AA was chemically isolated from natural cashew nutshell liquid obtained by continuous extraction in a Soxhlet extractor and was fully saturated by catalytic hydrogenation. Matrix metalloproteinase 2 (MMP-2) activity, when exposed to buffers containing 100 µmol/l AA, was analyzed using zymography. Bovine root samples were subjected to erosive demineralization (Sprite Zero™, 4 × 90 s/day) and remineralization with artificial saliva between the erosive cycles for 5 days. The samples were treated as follows, after the first and the last acid exposure (1 min; n = 12/group): (1) 100 µmol/l epigallocatechin-3-gallate (EGCG) (positive control); (2) 0.05% NaF; (3) 100 µmol/l saturated AA; (4) saturated AA and EGCG; (5) saturated AA, EGCG and NaF; (6) untreated (negative control). Dentine erosion was measured using a contact profilometer. Two dentine samples from each group were analyzed using scanning electron microscopy. Saturated AA reduced the activity of MMP-2. ANOVA and Tukey's test revealed that all treatments significantly reduced dentine loss compared to the negative control (6.03 ± 0.98 µm). Solutions containing saturated AA (1.97 ± 1.02 µm) showed the greatest reduction in dentine erosion compared to the NaF (3.93 ± 1.54 µm) and EGCG (3.79 ± 0.83 µm) solutions. Therefore, it may be concluded that AA significantly reduces dentine erosion in vitro, possibly by acting as an MMP-2 inhibitor.

Nondestructive assessment of dentin demineralization using polarization sensitive optical coherence tomography after exposure to fluoride and laser irradiation

PubMed Central

Manesh, Saman K.; Darling, Cynthia L.; Fried, Daniel

2009-01-01

Previous studies have demonstrated that polarization sensitive optical coherence tomography (PS-OCT) can be used to image natural and artificial caries in dentin. The purpose of this study was to measure non-destructively the severity of artificial caries lesions in dentin and determine the efficacy of intervention with anti-caries agents including fluoride and lasers. Although several studies have assessed the utility of PS-OCT to image caries lesions in enamel and to quantify the lesion severity, only a few studies have focused on lesions in dentin. In this study images of artificial dentin lesions on extracted human teeth were acquired with PS-OCT. Before exposure to an artificial demineralizing solution, three incisions were made on the sample surfaces using either Er:YAG, Nd:YAG (λ=355-nm), or TEA CO2 lasers and selected areas were treated with topical fluoride to create six unique treatment areas for each of the three laser conditions investigated. The integrated reflectivity and depth of demineralization were calculated for each of the six areas on each sample using the PS-OCT images. Polarized light microscopy (PLM) and transverse microradiography (TMR) were used to measure lesion severity on histological thin sections for comparison. PS-OCT successfully measured the inhibition of demineralization by topical fluoride. Laser irradiation was not particularly effective in increasing or decreasing the rate of dentin demineralization. PLM and TMR corroborated those results. This study demonstrates that PS-OCT can be used to measure demineralization on dentin surfaces and determine the degree of inhibition of demineralization by anti-caries agents. PMID:19283826

Shear bond strengths of composite to dentin using six dental adhesive systems.

PubMed

Triolo, P T; Swift, E J; Barkmeier, W W

1995-01-01

The development of adhesive agents for bonding composite to dentin has rapidly evolved in recent years. It is postulated that dentin bond strengths in the range of 17 MPa are sufficient to resist the polymerization shrinkage of composite resins. The purpose of this study was to evaluate the shear bond strengths of the following dentin adhesive systems: All-Bond 2 (Bisco), Imperva Bond (Shofu), Optibond (Kerr), Permagen (Ultradent), ProBond (Caulk/Dentsply), and Scotchbond Multi-Purpose (3M). Sixty human molars (10 per group) were mounted in phenolic rings, and the occlusal surfaces were flat ground in dentin to 600 grit. The prepared dentin bonding sites were treated according to the directions for each of the systems evaluated. A gelatin capsule technique was used to bond Bis-Fil composite cylinders to the teeth. The specimens were stored in water at 37 degrees C for 24 hours. Mean shear bond strengths were as follows: Scotchbond Multi-Purpose: 23.1 +/- 2.6 MPa, All-Bond 2: 21.4 +/- 7.8 MPa, Imperva Bond: 19.8 +/- 6.1 MPa, Optibond: 19.7 +/- 3.6 MPa, ProBond: 16.3 +/- 4.5 MPa, and Permagen: 16.2 +/- 3.0 MPa. There was not a significant difference (P<0.05) in the bond strengths of Scotchbond Multi-Purpose, All-Bond 2, Imperva Bond, and Optibond. The bond strengths of Scotchbond Multi-Purpose and All-Bond 2 were significantly greater (P<0.05) than ProBond and Permagen. Current-generation dentin adhesive systems have approached or exceeded the theoretical threshold value to resist contraction stresses during polymerization of resin materials.

Preventive effects of different protective agents on dentin erosion: An in vitro investigation

PubMed Central

Gulino, Chiara; Mirando, Maria; Colombo, Marco; Pietrocola, Giampiero

2017-01-01

Background The purpose of this in vitro study was to evaluate the preventive effects of different protective agents on dentine erosion, measuring mean percentage weight loss. Dissolution of dentine under erosive challenges caused by soft drinks was analyzed: specimens were weighed following each immersion period, with mean percent weight losses calculated. Material and Methods Extracted teeth were sectioned into uniform slabs. Seventy permanent enamel specimens were randomly distributed to seven groups. Initial weights of all dentin specimens were performed. The fluoride pastes Remin Pro, MI Paste Plus, Tooth Mousse, Biorepair, Biorepair Plus and Regenerate were used in this study. A control group was treated just with tap water. The specimens then were immersed in Coca-Cola for a total of 32 min at room temperature. Finally each specimen was dry and weighed. The mass loss was calculated as a percentage of that observed prior the fluoride pastes application. Weight loss data were subjected to Analysis of Variance (One-way ANOVA) followed by Bonferroni’s post hoc tests. Results Percent weight loss of specimens exposed to early stages in Coca-Cola showed linear progression with time. Specimen’s application of fluoridated varnishes such as Biorepair or Regenerate, prior immersion in Coca-Cola, significantly protect dentin from demineralization. Otherwise, application of Tooth Mousse or Biorepair Plus increased dentin demineralization starting from 24 min of immersion in Coca-Cola. Conclusions Despite the limitations of this study, the protective pastes that showed the less weight loss due to the acidic challenge are Biorepair and Regenerate. Key words:Dentine, erosion, protective agents, soft drinks, toothpastes. PMID:28149456

Preventive effects of different protective agents on dentin erosion: An in vitro investigation.

PubMed

Poggio, Claudio; Gulino, Chiara; Mirando, Maria; Colombo, Marco; Pietrocola, Giampiero

2017-01-01

The purpose of this in vitro study was to evaluate the preventive effects of different protective agents on dentine erosion, measuring mean percentage weight loss. Dissolution of dentine under erosive challenges caused by soft drinks was analyzed: specimens were weighed following each immersion period, with mean percent weight losses calculated. Extracted teeth were sectioned into uniform slabs. Seventy permanent enamel specimens were randomly distributed to seven groups. Initial weights of all dentin specimens were performed. The fluoride pastes Remin Pro, MI Paste Plus, Tooth Mousse, Biorepair, Biorepair Plus and Regenerate were used in this study. A control group was treated just with tap water. The specimens then were immersed in Coca-Cola for a total of 32 min at room temperature. Finally each specimen was dry and weighed. The mass loss was calculated as a percentage of that observed prior the fluoride pastes application. Weight loss data were subjected to Analysis of Variance (One-way ANOVA) followed by Bonferroni's post hoc tests. Percent weight loss of specimens exposed to early stages in Coca-Cola showed linear progression with time. Specimen's application of fluoridated varnishes such as Biorepair or Regenerate, prior immersion in Coca-Cola, significantly protect dentin from demineralization. Otherwise, application of Tooth Mousse or Biorepair Plus increased dentin demineralization starting from 24 min of immersion in Coca-Cola. Despite the limitations of this study, the protective pastes that showed the less weight loss due to the acidic challenge are Biorepair and Regenerate. Key words: Dentine, erosion, protective agents, soft drinks, toothpastes.

Polymerization contraction stress in dentin adhesives bonded to dentin and enamel.

PubMed

Hashimoto, Masanori; de Gee, Anton J; Feilzer, Albert J

2008-10-01

In a previous study on of polymerization contraction stress determinations of adhesives bonded to dentin a continuous decline of stress was observed after the adhesives had been light-cured. The decline was ascribed to stress relief caused by diffusion into the adhesive layer of water and/or solvents, left in the impregnated dentin surface after drying and/or evaporation in the application procedure. The purpose of the present study was to test the hypothesis that the contraction stress of adhesives bonded to enamel will not decline after light-curing, based on the assumption that water and/or solvents are more efficiently removed from impregnated enamel surfaces in the drying and/or evaporation step. Contraction stress was determined in a tensilometer for three total-etching adhesives Scotchbond multi-purpose, Single bond and One-step plus and four self-etching adhesives Clearfil SE Bond, Clearfil Protect Bond, AdheSE, and Xeno III. The adhesives were placed in a thin layer between a glass plate and a flat dentin or enamel surface pre-treated with phosphoric acid or self-etching primer and light-cured under constrained conditions. All adhesives bonded to enamel showed a stress decline, but significantly less than for dentin with the exception of two self-etching adhesives. The greatest decline was found for the total-etching adhesive systems bonded to dentin. The presence of hydrophobic monomers in the adhesives had a significant influence on the decline. The experiments indicate that fluids are withdrawn from the resin impregnated tooth structures, which may result in small defects in the tooth-resin interfaces.

Amalgam shear bond strength to dentin using single-bottle primer/adhesive systems.

PubMed

Cobb, D S; Denehy, G E; Vargas, M A

1999-10-01

To evaluate the in vitro shear bond strengths (SBS) of a spherical amalgam alloy (Tytin) to dentin using several single-bottle primer/adhesive systems both alone: Single Bond (SB), OptiBond Solo (Sol), Prime & Bond 2.1 (PB), One-Step (OS) and in combination with the manufacturer's supplemental amalgam bonding agent: Single Bond w/3M RelyX ARC (SBX) and Prime & Bond 2.1 w/Amalgam Bonding Accessory Kit (PBA). Two, three-component adhesive systems, Scotchbond Multi-Purpose (SBMP) and Scotchbond Multi-Purpose Plus w/light curing (S + V) and w/o light curing (S+) were used for comparison. One hundred eight extracted human third molars were mounted lengthwise in phenolic rings with acrylic resin. The proximal surfaces were ground to expose a flat dentin surface, then polished to 600 grit silicon carbide paper. The teeth were randomly assigned to 9 groups (n = 12), and dentin surfaces in each group were treated with an adhesive system according to the manufacturer's instructions, except for S + V specimens, where the adhesive was light cured for 10 s before placing the amalgam. Specimens were then secured in a split Teflon mold, having a 3 mm diameter opening and amalgam was triturated and condensed onto the treated dentin surfaces. Twenty minutes after condensation, the split mold was separated. Specimens were placed in distilled water for 24 hrs, then thermocycled (300 cycles, between 5 degrees C and 55 degrees C, with 12 s dwell time). All specimens were stored in 37 degrees C distilled water for 7 days, prior to shear strength testing using a Zwick Universal Testing Machine at a cross-head speed of 0.5 mm/min. The highest to the lowest mean dentin shear bond strength values (MPa) for the adhesive systems tested were: S + V (10.3 +/- 2.3), SBX (10.2 +/- 3.5), PBA, (6.4 +/- 3.6), SOL (5.8 +/- 2.5), SBMP (5.7 +/- 1.8), S+ (4.8 +/- 2.3), PB (2.7 +/- 2.6), SB (2.7 +/- 1.1) and OS (2.5 +/- 1.8). One-way ANOVA and Duncan's Multiple Range Test indicated significant differences among groups. SBX and S + V produced significantly higher amalgam to dentin shear bond strengths than all other adhesive systems. Bond strengths of amalgam to dentin for the single-bottle adhesives, SOL and PBA were comparable to the three-component systems, SBMP and S+ and were significantly greater than OS, SB and PB (P < 0.05).

Effects of NaOCl, EDTA and MTAD when applied to dentine on stress distribution in post-restored roots with flared canals.

PubMed

Belli, S; Eraslan, O; Eraslan, O; Eskitascioglu, M; Eskitascioglu, G

2014-12-01

To evaluate the effect of NaOCl, EDTA and MTAD on the stress distribution and levels in roots with flared canals and three different aesthetic post systems using finite element stress analysis (FEA). Three-dimensional (3D) FEA models simulating a maxillary incisor with excessive structural loss and flared root canals were created. The dentine of the first models of each post group was assumed as homogenous, whereas the others were deemed as having their elastic modulus affected up to 100 μm deep as a result of irrigation protocol (5.25 NaOCl, 17% EDTA and MTAD for 2 h). A sound incisor tooth model was used as the control. Restorations were created according to the post system used (pre-fabricated fibre post (PFP)), polyethylene fibre (Ribbond) post and core build-up (RBP), and one-piece milled zirconia post and core (ZP). Ceramic crowns were added to the models. A 300-N static load was applied at the centre of the palatal surface of the models to calculate the stress distributions. The SolidWorks/Cosmosworks structural analysis programmes were used for FEA analysis. Results were presented by considering von Mises criteria. The analysis of the von Mises stresses revealed that RBP created less stress in the remaining root dentine when compared to PFP and ZP. ZP maintained the stresses inside its body and reduced stress on the palatal surface of the root; however, it forwarded more stress towards the apical area. NaOCl-, EDTA- and MTAD-treated dentine increased the stresses within the root structure regardless of the effect of the post system used (11-15.4 MPa for PFP, 9.5-13.02 MPa for RBP and 14.2 MPa for ZP). Amongst the irrigation solutions used, EDTA and MTAD increased the stresses more than NaOCl in all models. All the irrigation solutions showed the same stress levels and distributions in the ZP model. NaOCl-, EDTA- and MTAD- treated dentine and a rigid post with high elastic modulus may increase fracture risk in roots with flared canals by increasing the stresses within root dentine. Therefore, solutions that alter the elastic modulus of dentine less (such as NaOCl) or an individually shaped post-core system constructed with a material that has an elastic modulus close to dentine (polyethylene fibre) should be used in weak roots. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Real-Time Binding Kinetic Analyses of the Interaction of the Dietary Stain Orange II with Dentin Matrix.

PubMed

Alraies, Amr; Cole, David K; S Rees, Jeremy; Glasse, Carl; Young, Nigel; Waddington, Rachel J; Sloan, Alastair J

2018-06-09

Dietary stains can be adsorbed into the dentin of teeth. Using Orange II as a model dietary stain, this study investigated the strength of its interaction with the mineral and protein components of dentin matrix and how hydrogen peroxide (H 2 O 2 ) treatment influences this interaction. Dentin slices were prepared from human teeth and were either deproteinized (5.6% sodium hypochlorite, 12 days), demineralised (0.5 M EDTA, 3 days) or left as intact control samples. Samples were stained with Orange II for 1-168 h, during which staining intensity was quantified by image analysis. Similarly, uptake of stain by deproteinized / demineralized samples treated with 10 or 30% H 2 O 2 was investigated. Using surface plasmon resonance technology, real-time binding kinetics were determined assessing the interaction of orange II with the dentin matrix protein constituents, collagen type I, biglycan, decorin, dentin sialoprotein and osteopontin. Deproteinization of dentin matrix reduced the uptake of the orange II compared to the intact control. Conversely, demineralization of dentin samples increased the uptake of the dye. Treatment of samples for 48 h with H 2 O 2 reduced subsequent uptake of the orange II. Real-time kinetic analysis indicated moderate strength of binding for Orange II with collagen type I, weak binding with decorin and biglycan and negligible binding with dentine sialoprotein and osteopontin. These results indicate a predominant role for collagen type I, which accounts for 90% of the organic protein matrix of teeth, for attracting dietary stains. Binding analyses indicate that the interaction is highly dissociable, and further binding is reduced following H 2 O 2 treatment. This study provides new information regarding adsorption of dietary stains into tooth dentin, suggesting that they are attracted and moderately bound to the collagen type I matrix. This study also contributes valuable information for discussion for considering the effect of H 2 O 2 on bleaching teeth and its influence on subsequent uptake of dietary stains following whitening treatments. Copyright © 2018. Published by Elsevier Ltd.

Paucity of Nanolayering in Resin-Dentin Interfaces of MDP-based Adhesives

PubMed Central

Tian, F.; Zhou, L.; Zhang, Z.; Niu, L.; Zhang, L.; Chen, C.; Zhou, J.; Yang, H.; Wang, X.; Fu, B.; Huang, C.; Pashley, D.H.; Tay, F.R.

2015-01-01

Self-assembled nanolayering structures have been reported in resin-dentin interfaces created by adhesives that contain 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP). These structures have been hypothesized to contribute to bond durability. The objective of the present study was to determine the extent of nanolayering in resin-dentin interfaces after application of commercialized 10-MDP-containing self-etch and universal adhesives to human dentin. Seven commercialized adhesives were examined: Adhese Universal (Ivoclar-Vivadent), All-Bond Universal (Bisco, Inc.), Clearfil SE Bond 2, Clearfil S3 Bond Plus, Clearfil Universal Bond (all from Kuraray Noritake Dental Inc.), G-Premio Bond (GC Corp.), and Scotchbond Universal (3M ESPE). Each adhesive was applied in the self-etch mode on midcoronal dentin according to the respective manufacturer’s instructions. Bonded specimens (n = 6) were covered with flowable resin composite, processed for transmission electron microscopy, and examined at 30 random sites without staining. Thin-film glancing angle X-ray diffraction (XRD) was used to detect the characteristic peaks exhibited by nanolayering (n = 4). The control consisted of 15%wt, 10%wt, and 5%wt 10-MDP (DM Healthcare Products, Inc.) dissolved in a mixed solvent (ethanol and water weight ratio 9:8, with photoinitiators). Experimental primers were applied to dentin for 20 s, covered with hydrophobic resin layer, and examined in the same manner. Profuse nanolayering with highly ordered periodicity (~3.7 nm wide) was observed adjacent to partially dissolved apatite crystallites in dentin treated with the 15% 10-MDP primer. Three peaks in the 2θ range of 2.40° (3.68 nm), 4.78° (1.85 nm), and 7.18° (1.23 nm) were identified from thin-film XRD. Reduction in the extent of nanolayering was observed in the 10% and 5% 10-MDP experimental primer-dentin interface along with lower intensity XRD peaks. Nanolayering and characteristic XRD peaks were rarely observed in specimens prepared from the commercialized adhesives. The sparsity of nanolayering in resin-dentin interfaces created by commercialized adhesives challenges its clinical effectiveness as a mechanism for improving bond longevity in dentin bonding. PMID:26701351

Paucity of Nanolayering in Resin-Dentin Interfaces of MDP-based Adhesives.

PubMed

Tian, F; Zhou, L; Zhang, Z; Niu, L; Zhang, L; Chen, C; Zhou, J; Yang, H; Wang, X; Fu, B; Huang, C; Pashley, D H; Tay, F R

2016-04-01

Self-assembled nanolayering structures have been reported in resin-dentin interfaces created by adhesives that contain 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP). These structures have been hypothesized to contribute to bond durability. The objective of the present study was to determine the extent of nanolayering in resin-dentin interfaces after application of commercialized 10-MDP-containing self-etch and universal adhesives to human dentin. Seven commercialized adhesives were examined: Adhese Universal (Ivoclar-Vivadent), All-Bond Universal (Bisco, Inc.), Clearfil SE Bond 2, Clearfil S3 Bond Plus, Clearfil Universal Bond (all from Kuraray Noritake Dental Inc.), G-Premio Bond (GC Corp.), and Scotchbond Universal (3M ESPE). Each adhesive was applied in the self-etch mode on midcoronal dentin according to the respective manufacturer's instructions. Bonded specimens (n = 6) were covered with flowable resin composite, processed for transmission electron microscopy, and examined at 30 random sites without staining. Thin-film glancing angle X-ray diffraction (XRD) was used to detect the characteristic peaks exhibited by nanolayering (n = 4). The control consisted of 15%wt, 10%wt, and 5%wt 10-MDP (DM Healthcare Products, Inc.) dissolved in a mixed solvent (ethanol and water weight ratio 9:8, with photoinitiators). Experimental primers were applied to dentin for 20 s, covered with hydrophobic resin layer, and examined in the same manner. Profuse nanolayering with highly ordered periodicity (~3.7 nm wide) was observed adjacent to partially dissolved apatite crystallites in dentin treated with the 15% 10-MDP primer. Three peaks in the 2θ range of 2.40° (3.68 nm), 4.78° (1.85 nm), and 7.18° (1.23 nm) were identified from thin-film XRD. Reduction in the extent of nanolayering was observed in the 10% and 5% 10-MDP experimental primer-dentin interface along with lower intensity XRD peaks. Nanolayering and characteristic XRD peaks were rarely observed in specimens prepared from the commercialized adhesives. The sparsity of nanolayering in resin-dentin interfaces created by commercialized adhesives challenges its clinical effectiveness as a mechanism for improving bond longevity in dentin bonding. © International & American Associations for Dental Research 2015.

Heat propagation in dentin during instrumentation with different sonic scaler tips.

PubMed

Kocher, T; Plagmann, H C

1996-04-01

It is important to know how much heat is generated when a root surface is debrided with sonic scalers and if that heat can be released satisfactorily into the environment. The temperature changes that occurred in dentinal specimens treated with two different sonic scaler tips, used with and without coolant, were studied. Temperature increases of up to 4 degrees C were observed for both tips when a coolant was used. Heat propagation during instrumentation was dependent to a considerable degree on the temperature of the coolant. Sonic scalers should not be used without coolant, because the dentinal temperature may increase up to 35 degrees C, depending on the force of application. A high positive linear correlation was found between increase in temperature and force of application.

Microleakage in Class V cavities with self-etching adhesive system and conventional rotatory or laser Er,Cr:YSGG

PubMed Central

Arnabat, J; España-Tost, T

2012-01-01

Objective: To analyse microleakage in Class V cavity preparation with Er;Cr:YSGG at different parameters using a self-etching adhesive system. Background: Several studies reported microleakage around composite restorations when cavity preparation is done or treated by Er;Cr:YSGG laser. We want to compare different energy densities in order to obtain the best parameters, when using a self-etching adhesive system. Methods: A class V preparations was performed in 120 samples of human teeth were divided in 3 groups: (1) Preparation using the burr. (2) Er;Cr:YSGG laser preparation with high energy 4W, 30 Hz, 50% Water 50% Air and (3) Er;Cr:YSGG laser preparation lower energy 1.5 W, 30 Hz, 30% Water 30% Air. All the samples were restored with self-etching adhesive system and hybrid composite. Thermocycling (5000 cycles) and immersed in 0.5% fuchsin. The restorations were sectioned and evaluated the microleakage with a stereomicroscope. Results: Lower energy laser used for preparation showed significant differences in enamel and dentin. To group 3, the microleakage in the enamel was less, whilst the group 1, treated with the turbine, showed less microleakage at dentin level. Group 2 showed the highest microleakage at dentin/cement level. Conclusion: Burr preparation gives the lowest microleakage at cement/dentin level, whilst Er;Cr:YSGG laser at lower power has the low energy obtains lowest microleakage at enamel. On the contrary high-energy settings produce inferior results in terms of microleakage. PMID:24511195

Xenogenous Collagen Matrix and/or Enamel Matrix Derivative for Treatment of Localized Gingival Recessions: A Randomized Clinical Trial. Part II: Patient-Reported Outcomes.

PubMed

Rocha Dos Santos, Manuela; Sangiorgio, João Paulo Menck; Neves, Felipe Lucas da Silva; França-Grohmann, Isabela Lima; Nociti, Francisco Humberto; Silverio Ruiz, Karina Gonzales; Santamaria, Mauro Pedrine; Sallum, Enilson Antonio

2017-12-01

Gingival recession (GR) might be associated with patient discomfort due to cervical dentin hypersensitivity (CDH) and esthetic dissatisfaction. The aim is to evaluate the effect of root coverage procedure with a xenogenous collagen matrix (CM) and/or enamel matrix derivative (EMD) in combination with a coronally advanced flap (CAF) on CDH, esthetics, and oral health-related quality of life (OHRQoL) of patients with GR. Sixty-eight participants with single Miller Class I/II GRs were treated with CAF (n = 17), CAF + CM (n = 17), CAF + EMD (n = 17), and CAF + CM + EMD (n = 17). CDH was assessed by evaporative stimuli using a visual analog scale (VAS) and a Schiff scale. Esthetics outcome was assessed with VAS and the Questionnaire of Oral Esthetic Satisfaction. Oral Health Impact Profile-14 (OHIP-14) questionnaire was used to assess OHRQoL. All parameters were evaluated at baseline and after 6 months. Intragroup analysis showed statistically significant reduction in CDH and esthetic dissatisfaction with no intergroup significant differences (P >0.05). The impact of oral health on QoL after 6 months was significant for CAF + CM, CAF + EMD, and CAF + CM + EMD (P <0.05). Total OHIP-14 score and psychologic discomfort, psychologic disability, social disability, and handicap dimensions showed negative correlation with esthetics. OHIP-14 physical pain dimension had positive correlation with CDH (P <0.05). OHIP-14 showed no correlation with percentage of root coverage, keratinized tissue width, or keratinized tissue thickness (P >0.05). Root coverage procedures improve patient OHRQoL by impacting on a wide range of dimensions, perceived after reduction of CDH and esthetic dissatisfaction of patients with GRs treated with CAF + CM, CAF + EMD, and CAF + CM + EMD.

Effect of oxalic acid pre-treatment in restorations of non-carious cervical lesions: A randomized clinical trial.

PubMed

de Souza, André Mattos Brito; Colares, Regina Claudia Ramos; Mendonça, Juliano Satori; Rodrigues, Lidiany Karla Azevedo; Santiago, Sérgio Lima

2014-09-01

Non-carious cervical lesions are usually associated with dentin hypersensitivity. The use of oxalic acid in restorations of these lesions could be beneficial in relieving pain. To evaluate the use of oxalic acid in restorations of non-carious cervical lesions. A randomized clinical trial. One operator placed 90 restorations in 20 volunteers of both sexes, with at least two lesions to be restored with the techniques: Control - Restoration with total-etch technique and Experimental - Restoration with pretreatment with oxalic acid followed by application of adhesive system. The restorative adhesive system used was XP Bond/Durafill. The restorations were directly assessed by two independent examiners using a modified United States Public Health Service (USPHS) method at baseline, 6 and 12 months, taking into account the following criteria: Retention (R), marginal integrity (MI), marginal discoloration (MD), postoperative sensitivity (S), caries (C), and anatomic form (AF). The data were statistically analyzed using the Fisher exact and McNemar tests. The level of significance was set at 5%. After 1 year, the results of restorations clinically satisfactory obtained for the control and experimental group respectively were: R (97% / 89%), MI (100% / 100%), MD (100% / 100%), S (100% / 100%), C (100% / 100%), and AF (100% / 100%). The use of oxalic acid as an agent of dentin pretreatment did not influence the clinical performance of restorations in non-carious cervical lesions after 1 year.

Laser Teeth Bleaching: Evaluation of Eventual Side Effects on Enamel and the Pulp and the Efficiency In Vitro and In Vivo

PubMed Central

De Moor, Roeland Jozef Gentil; Meire, Maarten August; De Coster, Peter Jozef

2015-01-01

Light and heat increase the reactivity of hydrogen peroxide. There is no evidence that light activation (power bleaching with high-intensity light) results in a more effective bleaching with a longer lasting effect with high concentrated hydrogen peroxide bleaching gels. Laser light differs from conventional light as it requires a laser-target interaction. The interaction takes place in the first instance in the bleaching gel. The second interaction has to be induced in the tooth, more specifically in the dentine. There is evidence that interaction exists with the bleaching gel: photothermal, photocatalytical, and photochemical interactions are described. The reactivity of the gel is increased by adding photocatalyst of photosensitizers. Direct and effective photobleaching, that is, a direct interaction with the colour molecules in the dentine, however, is only possible with the argon (488 and 415 nm) and KTP laser (532 nm). A number of risks have been described such as heat generation. Nd:YAG and especially high power diode lasers present a risk with intrapulpal temperature elevation up to 22°C. Hypersensitivity is regularly encountered, being it of temporary occurrence except for a number of diode wavelengths and the Nd:YAG. The tooth surface remains intact after laser bleaching. At present, KTP laser is the most efficient dental bleaching wavelength. PMID:25874258

Astrometry of comets using hypersensitized type 2415 film

NASA Technical Reports Server (NTRS)

Everhart, E.

1984-01-01

Kodak Technical Pan Film 2415 should be known to those doing cometary astrometry. It has exceedingly fine resolution (320 lines/mm) and, when properly hypersensitized, it is almost as fast as treated IIIa-J plates and reaches fainter stars. Reciprocity failure with the treated film is practically zero, and the shelf life of treated film sheets is about a month at 2 C stored in a nitrogen atmosphere. This film is readily available in 4 by 5-inch sheets and is inexpensive. The film base is Estar, a plastic chosen for its stability. Over 120 astrometric measures of negatives on this film have shown a median residual error in comet positions of 1.1 seconds, a value that compares favorably with those of most observatories reporting positions.

In Vitro Adhesion of Streptococcus sanguinis to Dentine Root Surface After Treatment with Er:Yag Laser, Ultrasonic System, or Manual Curette

PubMed Central

Martins, Fernanda L.; Giorgetti, Ana Paula O.; de Freitas, Patrícia M.; Duarte, Poliana M.

2009-01-01

Abstract Objective: The purpose of this in vitro study was to evaluate the dentine root surface roughness and the adherence of Streptococcus sanguinis (ATCC 10556) after treatment with an ultrasonic system, Er:YAG laser, or manual curette. Background Data: Bacterial adhesion and formation of dental biofilm after scaling and root planing may be a challenge to the long-term stability of periodontal therapy. Materials and Methods: Forty flattened bovine roots were randomly assigned to one of the following groups: ultrasonic system (n = 10); Er:YAG laser (n = 10); manual curette (n = 10); or control untreated roots (n = 10). The mean surface roughness (Ra, μm) of the specimens before and after exposure to each treatment was determined using a surface profilometer. In addition, S. sanguinis was grown on the treated and untreated specimens and the amounts of retained bacteria on the surfaces were measured by culture method. Results: All treatments increased the Ra; however, the roughest surface was produced by the curettes. In addition, the specimens treated with curettes showed the highest S. sanguinis adhesion. There was a significant positive correlation between roughness values and bacterial cells counts. Conclusion: S. sanguinis adhesion was the highest on the curette-treated dentine root surfaces, which also presented the greatest surface roughness. PMID:19712018

Assessment of radicular dentin permeability after irradiation with CO2 laser and endodontic irrigation treatments with thermal imaging

NASA Astrophysics Data System (ADS)

Cho, Heajin; Lee, Robert C.; Chan, Kenneth H.; Fried, Daniel

2017-02-01

Previous studies have demonstrated that the permeability changes due to the surface modification of dentin can be quantified via thermal imaging during dehydration. The CO2 laser has been shown to remove the smear layer and disinfect root canals. Moreover, thermal modification via CO2 laser irradiation can be used to convert dentin into a highly mineralized enamel-like mineral. The purpose of this study is to evaluate the radicular dentin surface modification after CO2 laser irradiation by measuring the permeability with thermal imaging. Human molar specimens (n=12) were sectioned into 4 axial walls of the pulp chamber and treated with either 10% NaClO for 1 minute, 5% EDTA for 1 minute, CO2 laser or none. The CO2 laser was operated at 9.4 μm with a pulse duration of 26 μs, pulse repetition rate of 300 Hz and a fluence of 13 J/cm2. The samples were dehydrated using an air spray for 60 seconds and imaged using a thermal camera. The resulting surface morphological changes were assessed using 3D digital microscopy. The images from digital microscopy confirmed melting of the mineral phase of dentin. The area enclosed by the time-temperature curve during dehydration, ▵Q, measured with thermal imaging increased significantly with treatments with EDTA and the CO2 laser (P<0.05). These results indicate that the surface modification due to CO2 laser treatment increases permeability of radicular dentin.

Effect of salivary contamination and decontamination on bond strength of two one-step self-etching adhesives to dentin of primary and permanent teeth.

PubMed

Santschi, Katharina; Peutzfeldt, Anne; Lussi, Adrian; Flury, Simon

2015-02-01

To evaluate the effects of human saliva contamination and two decontamination procedures at different stages of the bonding procedure on the bond strength of two one-step self-etching adhesives to primary and permanent dentin. Extracted human primary and permanent molars (210 of each) were ground to mid-coronal dentin. The dentin specimens were randomly divided into 7 groups (n = 15/group/molar type) for each adhesive (Xeno V+ and Scotchbond Universal): no saliva contamination (control); saliva contamination before or after light curing of the adhesives followed by air drying, rinsing with water spray/air drying, or by rinsing with water spray/air drying/reapplication of the adhesives. Resin composite (Filtek Z250) was applied on the treated dentin surfaces. The specimens were stored at 37°C and 100% humidity for 24 h. After storage, shear bond strength (SBS) was measured and data analyzed with nonparametric ANOVA followed by exact Wilcoxon rank sum tests. Xeno V+ generated significantly higher SBS than Scotchbond Universal when no saliva contamination occurred. Saliva contamination reduced SBS of Xeno V+, with the reduction being more pronounced when contamination occurred before light curing than after. In both situations, decontamination involving reapplication of the adhesive restored SBS. Saliva contamination had no significant effect on Scotchbond Universal. There were no differences in SBS between primary and permanent teeth. Rinsing with water and air drying followed by reapplication of the adhesive restored bond strength to saliva-contaminated dentin.

Zinc oxide eugenol paste jeopardises the adhesive bonding to primary dentine.

PubMed

Pires, C W; Lenzi, T L; Soares, F Z M; Rocha, R O

2018-05-12

This was to evaluate the influence of root canal filling pastes on microshear bond strength (µSBS) of an adhesive system to primary dentine. Human (32) primary molars were randomly assigned into four experimental groups (n = 8): zinc oxide eugenol paste (ZOE); iodoform paste (Guedes-Pinto paste); calcium hydroxide paste thickened with zinc oxide; and no filling paste (control). Flat dentine surfaces were covered with a 1 mm-thick layer of the pastes for 15 min at 37 °C. The pastes were mechanically removed from dentine surfaces, followed by rinsing and drying. After adhesive application (Adper Single Bond 2, 3M ESPE), starch tubes were placed over pre-treated dentine and filled with composite resin (Z250, 3M ESPE). The µSBS test was performed after 24 h of water storage at 37 °C. The failure mode was evaluated using a stereomicroscope. The µSBS values (MPa) were analysed with one-way ANOVA and Tukey post-hoc tests (α = 0.05). The lowest µSBS values were achieved when ZOE was used. No difference was found among other filling pastes compared with control group. All specimens showed adhesive/mixed failures. Zinc oxide eugenol paste negatively influenced the bond strength of adhesive systems to primary dentine. Iodoform-based Guedes-Pinto paste and calcium hydroxide paste thickened with zinc oxide did not influence the microshear bond strength values.

Characterization of Chlorhexidine-Loaded Calcium-Hydroxide Microparticles as a Potential Dental Pulp-Capping Material

PubMed Central

Priyadarshini, Balasankar M.; Selvan, Subramanian T.; Narayanan, Karthikeyan; Fawzy, Amr S.

2017-01-01

This study explores the delivery of novel calcium hydroxide [Ca(OH)2] microparticles loaded with chlorhexidine (CHX) for potential dental therapeutic and preventive applications. Herein, we introduce a new approach for drug-delivery to deep dentin-surfaces in the form of drug-loaded microparticles. Unloaded Ca(OH)2 [Ca(OH)2/Blank] and CHX-loaded/Ca(OH)2 microparticles were fabricated by aqueous chemical-precipitation technique. The synthesized-microparticles were characterized in vitro for determination of surface-morphology, crystalline-features and thermal-properties examined by energy-dispersive X-ray scanning and transmission electron-microscopy (EDX-SEM/TEM), Fourier-transform infrared-spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential scanning-calorimetry (DSC). Time-related pH changes, initial antibacterial/biofilm-abilities and cytotoxicity of CHX-loaded/Ca(OH)2 microparticles were evaluated. Microparticles were delivered to dentin-surfaces with subsequent SEM examination of treated dentin-substrates. The in vitro and ex vivo CHX-release profiles were characterized. Ca(OH)2/Blank were hexagonal-shaped with highest z-average diameter whereas CHX-inclusion evidenced micro-metric spheres with distinguishable surface “rounded deposits” and a negative-shift in diameter. CHX:Ca(OH)2/50 mg exhibited maximum encapsulation-efficiency with good antibacterial and cytocompatible properties. SEM examination revealed an intact layer of microparticles on exposed dentin-surfaces with retention of spherical shape and smooth texture. Microparticles loaded on dentin-surfaces showed prolonged release of CHX indicating substantial retention on dentin-substrates. This study validated the inherent-applicability of this novel drug-delivery approach to dentin-surfaces using micro-metric CHX-loaded/Ca(OH)2 microparticles. PMID:28952538

Push-out bond strengths of two fiber post types bonded with different dentin bonding agents.

PubMed

Topcu, Fulya Toksoy; Erdemir, Ugur; Sahinkesen, Gunes; Mumcu, Emre; Yildiz, Esra; Uslan, Ibrahim

2010-05-01

The aim of this study was to evaluate the regional push-out bond strengths for two fiber-reinforced post types using three different dentin bonding agents. Sixty single-rooted extracted human first premolar teeth were sectioned below the cemento-enamel junction, and the roots were endodontically treated. Following standardized post space preparations, the roots were divided into two fiber-post groups (Glassix and Carbopost), and further divided into three subgroups of 10 specimens each for the bonding systems self-etching dentin bonding agents (Clearfil SE Bond and Optibond all-in-one), and total-etching dentin bonding agent (XP Bond). A dual-cure resin luting cement (Maxcem) was then placed in the post spaces and posts were then seated into the root canals polymerized through the cervical portion. The roots were then cut into 3-mm thick sections. Push-out tests were performed at a crosshead speed of 0.5 mm/min. The data were analyzed with multivariate ANOVA (alpha = 0.05). The morphology of interface between different dentin bonding agents from the cervical sections were analyzed with SEM. Glass fiber-reinforced posts demonstrated significantly higher push-out bond strengths than carbon fiber-reinforced posts (p < 0.001). Bond strength values decreased significantly from the cervical to the apical root canal regions (p < 0.001). Self-etching dentin adhesive Clearfil SE Bond and total-etching dentin adhesive XP Bond demonstrated similar bond strengths values and this was significantly higher compared with the Optibond all-in-one in cervical root canal region. In conclusion, in all root segments, the glass fiber-reinforced posts provided significantly increased post retention than the carbon fiber-reinforced posts, regardless of the adhesive used. (c) 2010 Wiley Periodicals, Inc.

Influence of different etching modes on bond strength and fatigue strength to dentin using universal adhesive systems.

PubMed

Takamizawa, Toshiki; Barkmeier, Wayne W; Tsujimoto, Akimasa; Berry, Thomas P; Watanabe, Hedehiko; Erickson, Robert L; Latta, Mark A; Miyazaki, Masashi

2016-02-01

The purpose of this study was to determine the dentin bonding ability of three new universal adhesive systems under different etching modes using fatigue testing. Prime & Bond elect [PE] (DENTSPLY Caulk), Scotchbond Universal [SU] (3M ESPE), and All Bond Universal [AU] (Bisco) were used in this study. A conventional single-step self-etch adhesive, Clearfil Bond SE ONE [CS] (Kuraray Noritake Dental) was also included as a control. Shear bond strengths (SBS) and shear fatigue strength (SFS) to human dentin were obtained in the total-etch mode and self-etch modes. For each test condition, 15 specimens were prepared for the SBS and 30 specimens for SFS. SEM was used to examine representative de-bonded specimens, treated dentin surfaces and the resin/dentin interface for each test condition. Among the universal adhesives, PE in total-etch mode showed significantly higher SBS and SFS values than in self-etch mode. SU and AU did not show any significant difference in SBS and SFS between the total-etch mode and self-etch mode. However, the single-step self-etch adhesive CS showed significantly lower SBS and SFS values in the etch-and-rinse mode when compared to the self-etch mode. Examining the ratio of SFS/SBS, for PE and AU, the etch-and-rinse mode groups showed higher ratios than the self-etch mode groups. The influence of different etching modes on dentin bond quality of universal adhesives was dependent on the adhesive material. However, for the universal adhesives, using the total-etch mode did not have a negative impact on dentin bond quality. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Effect of NaF and TiF(4) varnish and solution on bovine dentin erosion plus abrasion in vitro.

PubMed

Magalhães, Ana Carolina; Levy, Flávia Mauad; Rizzante, Fábio A; Rios, Daniela; Buzalaf, Marília Afonso Rabelo

2012-03-01

This in vitro study aimed to analyze the effect of TiF(4) compared to NaF varnishes and solutions, to protect against dentin erosion associated with abrasion. Bovine dentin specimens were pre-treated with NaF-Duraphat (2.26% F), NaF/CaF(2)-Duofluorid (5.63% F), experimental-NaF (2.45% F), experimental-TiF(4) (2.45% F) and placebo varnishes; NaF (2.26% F) and TiF(4) (2.45% F) solutions. Controls remained untreated. The erosive pH cycling was performed using a soft drink (pH 2.6) 4 × 90 s/day and the toothbrushing-abrasion 2 × 10 s/day, in vitro for 5 days. Between the challenges, the specimens were exposed to artificial saliva. Dentin tissue loss was measured profilometrically (μm). ANOVA/Tukey's test showed that all fluoridated varnishes (Duraphat, 7.5 ± 1.1; Duofluorid, 6.8 ± 1.1; NaF, 7.2 ± 1.9; TiF(4), 6.5 ± 1.0) were able to significantly reduce dentin tissue loss (40.7% reduction compared to control) when compared to placebo varnish (11.2 ± 1.3), control (11.8 ± 1.7) and fluoridated (NaF, 9.9 ± 1.8; TiF(4), 10.3 ± 2.1) solutions (p < 0.0001), which in turn did not significantly differ from each other. All fluoridated varnishes, but not the solutions, had a similar performance and a good potential to reduce dentin tissue loss under mild erosive and abrasive conditions in vitro. Risk patients for erosion and abrasion, especially those with exposed dentin, should benefit from this clinical preventive measure. Further research has to confirm this promising result in the clinical situation.

Effect of low-level laser therapy (λ780 nm) on the mechanically damaged dentin-pulp complex in a model of extrusive luxation in rat incisors.

PubMed

de Santana, Dandara Andrade; Fonseca, Gabriela Ferraz; Ramalho, Luciana Maria Pedreira; Rodriguez, Tânia Tavares; Aguiar, Marcio Cajazeira

2017-12-01

In order to regenerate the dental pulp, many strategies have been developed as phototherapy. In the pulp repair, we do not know if gallium-aluminum-arsenide (GaAlAs) laser preserves the primary odontoblasts or stimulates the formation of more dentin matrix when dental pulp is damaged. The aim of the present study was to examine the effect of laser phototherapy (λ780 nm) on vascularization, inflammation, density of the primary odontoblast layer, and formation of reactionary and reparative dentin in the dental pulp by provoking extrusion of the rat incisor. The upper incisors were extruded 3 mm and then repositioned into their original sockets followed by a laser irradiation of the palatal mucosa (λ = 780 nm; p = 70 mW; CW; 4.2 J/cm 2 ; 60 s) every 48 h. Non-traumatized and/or non-irradiated incisors were used as the controls. At 8 and 30 days after surgery, incisors were processed for histological and histomorphometric analysis. Morphological analysis revealed no differences in vascularization between groups, but showed discrete inflammation in some non-irradiated and injured specimens, which correlated with a more irregular reparative dentin. The density of primary odontoblasts in the groups treated with lasers was higher when compared to non-irradiated groups, but no statistically significant difference between groups (p > 0.05). The thickness of the tertiary dentin was increased in both traumatized groups with no statistically significant difference between non-irradiated and irradiated groups (p > 0.05).The present findings revealed that the GaAlAs laser induced small changes on dentin-pulp complex, with more regular dentin matrix in the irradiated dental pulps.

A Chemical Phosphorylation-inspired Design for Type I Collagen Biomimetic Remineralization

PubMed Central

Gu, Li-sha; Kim, Jongryul; Kim, Young Kyung; Liu, Yan; Dickens, Sabine H.; Pashley, David H.; Ling, Jun-qi; Tay, Franklin R.

2010-01-01

Objectives Type I collagen alone cannot initiate tissue mineralization. Sodium trimetaphosphate (STMP) is frequently employed as a chemical phosphorylating reagent in the food industry. This study examined the feasibility of using STMP as a functional analog of matrix phosphoproteins for biomimetic remineralization of resin-bonded dentin. Methods Equilibrium adsorption and desorption studies of STMP were performed using demineralized dentin powder (DDP). Interaction between STMP and DDP was examined using Fourier-transform infrared spectroscopy. Based on those results, a bio-inspired mineralization scheme was developed for chemical phosphorylation of acid-etched dentin with STMP, followed by infiltration of the STMP-treated collagen matrix with two etch-and-rinse adhesives. Resin-dentin interfaces were remineralized in a Portland cement-simulated body fluid system, with or without the use of polyacrylic acid (PAA) as a dual biomimetic analog. Remineralized resin-dentin interfaces were examined unstained using transmission electron microscopy. Results Analysis of saturation binding curves revealed the presence of irreversible phosphate group binding sites on the surface of the DDP. FT-IR provided additional evidence of chemical interaction between STMP and DDP, with increased in the peak intensities of the P=O and P–O–C stretching modes. Those peaks returned to their original intensities after alkaline phosphatase treatment. Evidence of intrafibrillar apatite formation could be seen in incompletely resin-infiltrated, STMP-phosphorylated collagen matrices only when PAA was present in the SBF. Significance These results reinforce the importance of PAA for sequestration of amorphous calcium phosphate nanoprecursors in the biomimetic remineralization scheme. They also highlight the role of STMP as a templating analog of dentin matrix phosphoproteins for inducing intrafibrillar remineralization of apatite nanocrystals within the collagen matrix of incompletely resin-infiltrated dentin. PMID:20688381

Rationale behind the design and comparative evaluation of an all-in-one self-etch model adhesive.

PubMed

Kanehira, Masafumi; Finger, Werner J; Ishihata, Hiroshi; Hoffmann, Marcus; Manabe, Atsufumi; Shimauchi, Hidetoshi; Komatsu, Masashi

2009-06-01

To investigate and compare bonding and dentin sealing efficacy of a marketed all-in-one and an experimental model adhesive with minimum effective amounts of acidic monomer and water. Composition of model adhesive (NAD) in mass%: UDMA (45), 4-META (20), H2O (7.5), and acetone (27.5). For characterization of a reasonable NAD application procedure shear bond strengths (SBS, n=8) were determined on human enamel and dentin. Clearfil S3 Bond (TSB; Kuraray) served as reference. SBSs were evaluated after 10 min, 1 and 7 days, and 1 month, marginal adaptation (n=8) was assessed in cylindrical butt-joint dentin cavities. Diffusive and convective water fluxes through 1mm thick adhesive-coated dentin disks (n=6) were qualitatively and quantitatively analyzed. SBSs proved that application of NAD in one coat with 20s agitated dwell time was > or =20 MPa, enamel SBSs (24h) were 25 MPa, p>0.05. Dentin SBSs for TSB and NAD were not different (p>0.05) at the four stages (means: 18.9, 23.5, 25.4, and 23.6 MPa). Five and seven of the eight bonded restorations with TSB and NAD were gap-free (p>0.05). Dentin disks treated with EDTA from both sides or one side only were highly permeable for liquid, whereas adhesive-coated dentin disks showed no permeability at 0 and 2.5 kPa water pressure. Within the limitations of this study the model adhesive tested represents a promising basic composition for all-in-one adhesives, eliminating common problems encountered with single step adhesives such as phase separation and permeability.

Aspirin allergy desensitization in cerebrovascular disease. A report of two cases, literature review and management guide for the neurointerventionalist.

PubMed

Zuckerman, Scott L; Seder, David B; Tsujiura, Crystiana; Cushing, Deborah; Gallup, Holly; Mocco, J; Hanel, Richard A; Ecker, Robert D

2014-01-01

Aspirin (ASA) is the mainstay of treatment in cerebrovascular and systemic vascular disease. ASA hypersensitivity can pose a challenge to achieving optimum medical management prior to and after neurointerventional treatment. Desensitization to ASA is well described in the allergy and cardiovascular literature, but there are no similar discussions specific to neurointervention. The purpose of our study was to describe our experience with ASA hypersensitivity management and review the relevant literature. Two cases of patients with symptomatic cerebrovascular disease requiring neurointervention who were successfully desensitized to their ASA hypersensitivity prior to treatment are described. The subsequent literature is reviewed. Several ASA desensitization protocols exist and have been proven to successfully treat ASA hypersensitivity and allow for ASA therapy to be safely initiated. We describe several previously published protocols. ASA desensitization is a safe and simple way to manage ASA hypersensitivity. We provide comprehensive management guidelines for the neurointerventionalist engaging in ASA desensitization.

The influence of fluoride varnish on the attrition of dentine.

PubMed

Li, H; Watson, T F; Sherriff, M; Curtis, R; Bartlett, D W

2007-01-01

Previous investigations have shown the potential for fluoride to be protective in an abrasion/erosion laboratory model. The aim of this study was to investigate the effect of high concentrations of fluoride delivered in a varnish on attrition of dentine. Fifteen caries-free, intact lower third molar teeth were sectioned and the enamel removed by a water-cooled diamond disc. Polished dentine surfaces were divided into 8 areas, 4 of which were randomly covered with a high-concentration fluoride varnish for 24 h. The samples were subjected to 5,000 cycles of attrition bathed under artificial saliva. Microhardness testing adjacent to the wear scars showed no statistical difference between the fluoride-treated (71.42 KHN, SD 10.52) and control surfaces (72.66 KHN, SD 9.69). The volume of the wear scar was statistically greater for the fluoride-treated surface at 9.6 microm(3) (SD 4.92) and 8.13 microm(3) (SD 5.54) for the control areas (p = 0.029). The low pH of the fluoride varnish appears to have increased the amount of wear from attrition in this laboratory study. Copyright 2007 S. Karger AG, Basel.

Regeneration of dental pulp/dentine complex with a three-dimensional and scaffold-free stem-cell sheet-derived pellet.

PubMed

Na, Sijia; Zhang, Hao; Huang, Fang; Wang, Weiqi; Ding, Yin; Li, Dechao; Jin, Yan

2016-03-01

Dental pulp/dentine complex regeneration is indispensable to the construction of biotissue-engineered tooth roots and represents a promising approach to therapy for irreversible pulpitis. We used a tissue-engineering method based on odontogenic stem cells to design a three-dimensional (3D) and scaffold-free stem-cell sheet-derived pellet (CSDP) with the necessary physical and biological properties. Stem cells were isolated and identified and stem cells from root apical papilla (SCAPs)-based CSDPs were then fabricated and examined. Compact cell aggregates containing a high proportion of extracellular matrix (ECM) components were observed, and the CSDP culture time was prolonged. The expression of alkaline phosphatase (ALP), dentine sialoprotein (DSPP), bone sialoprotein (BSP) and runt-related gene 2 (RUNX2) mRNA was higher in CSDPs than in cell sheets (CSs), indicating that CSDPs have greater odonto/osteogenic potential. To further investigate this hypothesis, CSDPs and CSs were inserted into human treated dentine matrix fragments (hTDMFs) and transplanted into the subcutaneous space in the backs of immunodeficient mice, where they were cultured in vivo for 6 weeks. The root space with CSDPs was filled entirely with a dental pulp-like tissue with well-established vascularity, and a continuous layer of dentine-like tissue was deposited onto the existing dentine. A layer of odontoblast-like cells was found to express DSPP, ALP and BSP, and human mitochondria lined the surface of the newly formed dentine-like tissue. These results clearly indicate that SCAP-CSDPs with a mount of endogenous ECM have a strong capacity to form a heterotopic dental pulp/dentine complex in empty root canals; this method can be used in the fabrication of bioengineered dental roots and also provides an alternative treatment approach for pulp disease. Copyright © 2013 John Wiley & Sons, Ltd.

Lasers in Apicoectomy: A Brief Review.

PubMed

Mohammadi, Zahed; Jafarzadeh, Hamid; Shalavi, Sousan; Kinoshita, Jun-Ichiro; Giardino, Luciano

2017-02-01

Since the invention of laser, various applications for lasers in endodontics have been proposed, such as disinfection of the root canal system, canal shaping, pulp diagnosis, and apico-ectomy. One of the major applications of laser in endodontics is apicoectomy. The aim of this article is to review the benefits and drawbacks of laser applications in apicoectomy, including effect on apical seal, effect on dentin permeability, effect on postsurgery pain, effect on crack formation, effect on root-end morphology, effect on treatment outcome, and connective tissue response to laser-treated dentin.

Alteration of dentin-enamel mechanical properties due to dental whitening treatments.

PubMed

Zimmerman, B; Datko, L; Cupelli, M; Alapati, S; Dean, D; Kennedy, M

2010-05-01

The mechanical properties of dentin and enamel affect the reliability and wear properties of a tooth. This study investigated the influence of clinical dental treatments and procedures, such as whitening treatments or etching prior to restorative procedures. Both autoclaved and non-autoclaved teeth were studied in order to allow for both comparison with published values and improved clinical relevance. Nanoindentation analysis with the Oliver-Pharr model provided elastic modulus and hardness across the dentin-enamel junction (DEJ). Large increases were observed in the elastic modulus of enamel in teeth that had been autoclaved (52.0 GPa versus 113.4 GPa), while smaller increases were observed in the dentin (17.9 GPa versus 27.9 GPa). Likewise, there was an increase in the hardness of enamel (2.0 GPa versus 4.3 GPa) and dentin (0.5 GPa versus 0.7 GPa) with autoclaving. These changes suggested that the range of elastic modulus and hardness values previously reported in the literature may be partially due to the sterilization procedures. Treatment of the exterior of non-autoclaved teeth with Crest Whitestrips, Opalescence or UltraEtch caused changes in the mechanical properties of both the enamel and dentin. Those treated with Crest Whitestrips showed a reduction in the elastic modulus of enamel (55.3 GPa to 32.7 GPa) and increase in the elastic modulus of dentin (17.2 GPa to 24.3 GPa). Opalescence treatments did not significantly affect the enamel properties, but did result in a decrease in the modulus of dentin (18.5 GPa to 15.1 GPa). Additionally, as expected, UltraEtch treatment decreased the modulus and hardness of enamel (48.7 GPa to 38.0 GPa and 1.9 GPa to 1.5 GPa, respectively) and dentin (21.4 GPa to 15.0 GPa and 1.9 GPa to 1.5 GPa, respectively). Changes in the mechanical properties were linked to altered protein concentration within the tooth, as evidenced by fluorescence microscopy and Fourier transform infrared spectroscopy. Published by Elsevier Ltd.

Effect of calcium phosphate nanocomposite on in vitro remineralization of human dentin lesions.

PubMed

Weir, Michael D; Ruan, Jianping; Zhang, Ning; Chow, Laurence C; Zhang, Ke; Chang, Xiaofeng; Bai, Yuxing; Xu, Hockin H K

2017-09-01

Secondary caries is a primary reason for dental restoration failures. The objective of this study was to investigate the remineralization of human dentin lesions in vitro via restorations using nanocomposites containing nanoparticles of amorphous calcium phosphate (NACP) or NACP and tetracalcium phosphate (TTCP) for the first time. NACP was synthesized by a spray-drying technique and incorporated into a resin consisting of ethoxylated bisphenol A dimethacrylate (EBPADMA) and pyromellitic glycerol dimethacrylate (PMGDM). After restoring the dentin lesions with nanocomposites as well as a non-releasing commercial composite control, the specimens were treated with cyclic demineralization (pH 4, 1h per day) and remineralization (pH 7, 23h per day) for 4 or 8 weeks. Calcium (Ca) and phosphate (P) ion releases from composites were measured. Dentin lesion remineralization was measured at 4 and 8 weeks by transverse microradiography (TMR). Lowering the pH increased ion release of NACP and NACP-TTCP composites. At 56 days, the released Ca concentration in mmol/L (mean±SD; n=3) was (13.39±0.72) at pH 4, much higher than (1.19±0.06) at pH 7 (p<0.05). At 56 days, P ion concentration was (5.59±0.28) at pH 4, much higher than (0.26±0.01) at pH 7 (p<0.05). Quantitative microradiography showed typical subsurface dentin lesions prior to the cyclic demineralization/remineralization treatment, and dentin remineralization via NACP and NACP-TTCP composites after 4 and 8 weeks of treatment. At 8 weeks, NACP nanocomposite achieved dentin lesion remineralization (mean±SD; n=15) of (48.2±11.0)%, much higher than (5.0±7.2)% for dentin in commercial composite group after the same cyclic demineralization/remineralization regimen (p<0.05). Novel NACP-based nanocomposites were demonstrated to achieve dentin lesion remineralization for the first time. These results, coupled with acid-neutralization and good mechanical properties shown previously, indicate that the NACP-based nanocomposites are promising for restorations to inhibit caries and protect tooth structures. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Successful desensitization protocol for hypersensitivity reaction probably caused by dabrafenib in a patient with metastatic melanoma.

PubMed

Bar-Sela, Gil; Abu-Amna, Mahmoud; Hadad, Salim; Haim, Nissim; Shahar, Eduardo

2015-09-01

Vemurafenib and dabrafenib are both orally bioavailable small molecule agents that block mitogen activated protein kinase signalling in patients with melanoma and BRAF(V600E) mutation. Generalized hypersensitivity reactions to vemurafenib or dabrafenib have not been described. Continuing vemurafenib or dabrafenib therapy despite hypersensitivity reaction is especially important in patients with melanoma and BRAF(V600E) mutation, in whom this mutation plays a critical role in tumour growth. Desensitization protocols to overcome hypersensitivity reactions by gradual reintroduction of small amounts of the offending drug up to full therapeutic doses are available for many anti-cancer agents, including vemurafenib but, to the best of our knowledge, have not been reported for dabrafenib. We describe a patient with metastatic melanoma who developed Type I hypersensitivity reaction to vemurafenib and to subsequent treatment with dabrafenib, and who was successfully treated by drug desensitization which allowed safe prolonged continuation of dabrafenib. The development of hypersensitivity reactions for both dabrafenib and vemurafinib in the current case could be because these drugs have a similar chemical structure and cause a cross-reactivity. However, hypersensitivity reaction to a non-medicinal ingredient shared by the two drugs is also possible. Oral desensitization appears to be an option for patients with hypersensitivity Type I to dabrafenib. This approach may permit clinicians to safely administer dabrafenib to patients who experience hypersensitivity reactions to this life-prolonging medication. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Training in Good Psychiatric Management for Borderline Personality Disorder in Residency: An Aide to Learning Supportive Psychotherapy for Challenging-to-Treat Patients.

PubMed

Bernanke, Joel; McCommon, Benjamin

2018-01-01

Given many competing demands, psychotherapy training to competency is difficult during psychiatric residency. Good Psychiatric Management for borderline personality disorder (GPM) offers an evidence-based, simplified, psychodynamically informed framework for the outpatient management of patients with borderline personality disorder, one of the most challenging disorders psychiatric residents must learn to treat. In this article, we provide an overview of GPM, and show that training in GPM meets a requirement for training in supportive psychotherapy; builds on psychodynamic psychotherapy training; and applies to other severe personality disorders, especially narcissistic personality disorder. We describe the interpersonal hypersensitivity model used in GPM as a straightforward way for clinicians to collaborate with patients in organizing approaches to psychoeducation, treatment goals, case management, use of multiple treatment modalities, and safety. A modification of the interpersonal hypersensitivity model that includes intra-personal hypersensitivity can be used to address narcissistic problems often present in borderline personality disorder. We argue that these features make GPM ideally suited for psychiatry residents in treating their most challenging patients, provide clinical examples to illustrate these points, and report the key lessons learned by a psychiatry resident after a year of GPM supervision.

TiF(4) and NaF at pH 1.2 but not at pH 3.5 are able to reduce dentin erosion.

PubMed

Wiegand, Annette; Magalhães, Ana Carolina; Sener, Beatrice; Waldheim, Elena; Attin, Thomas

2009-08-01

This study aimed to analyse and compare the protective effect of buffered (pH 3.5) and native (pH 1.2) TiF(4) in comparison to NaF solutions of same pH on dentin erosion. Bovine samples were pretreated with 1.50% TiF(4) or 2.02% NaF (both 0.48M F) solutions, each with a pH of 1.2 and 3.5. The control group received no fluoride pretreatment. Ten samples in each group were eroded with HCl (pH 2.6) for 10x60s. Erosion was analysed by determination of calcium release into the acid. Additionally, the surface and the elemental surface composition were examined by scanning electron microscopy (two samples in each group) and X-ray energy-dispersive spectroscopy in fluoridated but not eroded samples (six samples in each group). Cumulative calcium release (nmol/mm(2)) was statistically analysed by repeated measures ANOVA and one-way ANOVA at t=10min. TiF(4) and NaF at pH 1.2 decreased calcium release significantly, while TiF(4) and NaF at pH 3.5 were not effective. Samples treated with TiF(4) at pH 1.2 showed a significant increase of Ti, while NaF pretreatment increased F concentration significantly. TiF(4) at pH 1.2 led to the formation of globular precipitates occluding dentinal tubules, which could not be observed on samples treated with TiF(4) at pH 3.5. NaF at pH 1.2 but not at pH 3.5 induced the formation of surface precipitates covering dentinal tubules. Dentin erosion can be significantly reduced by TiF(4) and NaF at pH 1.2, but not at pH 3.5.

Influence of chlorhexidine on dentin adhesive interface micromorphology and nanoleakage expression of resin cements.

PubMed

Stape, Thiago Henrique Scarabello; Menezes, Murilo De Sousa; Barreto, Bruno De Castro Ferreira; Naves, Lucas Zago; Aguiar, Flávio Henrique Baggio; Quagliatto, Paulo Sérgio; Martins, Luís Roberto Marcondes

2013-08-01

This study focused on adhesive interface morphologic characterization and nanoleakage expression of resin cements bonded to human dentin pretreated with 1% chlorhexidine (CHX). Thirty-two non-carious human third molars were ground flat to expose superficial dentin. Resin composite blocks were luted to the exposed dentin using one conventional (RelyX ARC) and one self-adhesive resin cement (RelyX U100), with/without CHX pretreatment. Four groups (n = 8) were obtained: control groups (ARC and U100); experimental groups (ARC/CHX and U100/CHX) were pretreated with 1% CHX prior to the luting process. After storage in water for 24 h, the bonded teeth were sectioned into 0.9 × 0.9 mm(2) sticks producing a minimum of 12 sticks per tooth. Four sticks from each tooth were prepared for hybrid layer evaluation by scanning electron microscope analysis. The remaining sticks were immersed in silver nitrate for 24 h for either nanoleakage evaluation along the bonded interfaces or after rupture. Nanoleakage samples were carbon coated and examined using backscattered electron mode. Well-established hybrid layers were observed in the groups luted with RelyX ARC. Nanoleakage evaluation revealed increase nanoleakage in groups treated with CHX for both resin cements. Group U100/CHX exhibited the most pronouncing nanoleakage expression along with porous zones adjacent to the CHX pretreated dentin. The results suggest a possible incompatibility between CHX and RelyX U100 that raises the concern that the use of CHX with self-adhesive cements may adversely affect resin-dentin bond. Copyright © 2013 Wiley Periodicals, Inc.

[Effect of three aging challenges on the bonding stability of resin-dentin interface using an etch-and-rinse adhesive].

PubMed

Xu, Shuai; Zhang, Ling; Li, Fang; Zhou, Wei; Chen, Yujiang; Chen, Jihua

2014-06-01

To systematically investigate the aging effect of thermocycling, water storage and bacteria aggression on the stability of resin-dentin bonds. Forty molars were sectioned perpendicularly to the axis of the teeth to expose the middle-coronal dentin surfaces. The dentin surfaces were then treated with Single Bond 2 and made a core build-up. According to random digits table, the bonding specimens were divided into four groups (n = 10) as follows: immediate control group, aging group with thermocycling for 5 000 times, aging group with artificial saliva storage for 6 months and aging group with bacteria aggression for 14 days. The specimens in each group were then subjected to microtensile bond strengths (µTBS) testing and nanoleakage evaluation respectively. After aging treatments, the three aging groups showed significantly lower µTBS than the immediate control group [(44.24 ± 12.75) MPa, P < 0.05]. The immediate control group also showed the lowest value of nanoleakage. The µTBS of aging group with bacteria aggression [(25.53 ± 7.39) MPa] was significantly lower than those of the other aging groups with artificial saliva storage[(29.72 ± 6.51) MPa] and thermocycling [(31.92 ± 11.87) MPa, P < 0.05]. There were no differences in the nanoleakage values among the three aging groups (P > 0.05). All the aging treatments with artificial saliva storage, thermocycling and bacteria aggression could accelerate the degradation of bonding interfaces between an etch-and-rinse adhesive and dentin. Bacteria aggression showed the most impairing effect on the stability of resin-dentin bonds.

Effect of the calcium silicate-based sealer removal protocols and time-point of acid etching on the dentin adhesive interface.

PubMed

Morais, Jéssika Mayhara Pereira; Victorino, Keli Regina; Escalante-Otárola, Wilfredo Gustavo; Jordão-Basso, Keren Cristina Fagundes; Palma-Dibb, Regina Guenka; Kuga, Milton Carlos

2018-06-15

The aim of the study was to evaluate the effects when acid etching on the dentin surface was immediately performed (I) or 7 days (D) after calcium silicate-based sealer (MTA Fillapex) removal, using 95% ethanol (E) or xylol (X). First study, 60 bovine incisor dentin specimens were impregnated with sealer and divided into six groups (n = 10): (EI), E + I; (XI), X + I; (ED), E + D; (XD), X + D, (UN), untreated and (MR), mechanical removal of sealer. Scanning electron microscopy (SEM) images (500×) were obtained from each specimen and scores assessed the sealer residues persistence. Second study, 60 specimens were similarly treated; however, the specimens were restored with composite resin after the removal protocols. Hybrid layer formation was evaluated using confocal laser microscopy (1,024×). Third study, 60 specimens were similarly obtained and subjected to micro-shear test to evaluate the effects of removal protocols on the bond strength of etch-and- rinse adhesive system to dentin. XI showed the highest persistence of sealer residues (p < .05), similar to MR (p > .05). EI showed the greatest hybrid layer extension, except in relation to UN (p < .05). XI and MR presented the lowest bond strength adhesive system to dentin (p < .05). Acid etching immediately after calcium silicate-based endodontic sealer removal using xylol presented the highest residues persistence and negatively affected the adhesive interface between dentin and etch-and-rinse adhesive system. © 2018 Wiley Periodicals, Inc.

Marginal adaptation of composite resins under two adhesive techniques.

PubMed

Dačić, Stefan; Veselinović, Aleksandar M; Mitić, Aleksandar; Nikolić, Marija; Cenić, Milica; Dačić-Simonović, Dragica

2016-11-01

In the present research, different adhesive techniques were used to set up fillings with composite resins. After the application of etch and rinse or self etch adhesive technique, marginal adaptation of composite fillings was estimated by the length of margins without gaps, and by the microretention of resin in enamel and dentin. The study material consisted of 40 extracted teeth. Twenty Class V cavities were treated with 35% phosphorous acid and restored after rinsing by Adper Single Bond 2 and Filtek Ultimate-ASB/FU 3M ESPE composite system. The remaining 20 cavities were restored by Adper Easy One-AEO/FU 3M ESPE composite system. Marginal adaptation of composite fillings was examined using a scanning electron microscope (SEM). The etch and rinse adhesive technique showed a significantly higher percentage of margin length without gaps (in enamel: 92.5%, in dentin: 57.3%), compared with the self-etch technique with lower percentage of margin length without gaps, in enamel 70.4% (p < .001), and in dentin-22.6% (p < .05). In the first technique, microretention was composed of adhesive and hybrid layers as well as resin tugs in interprismatic spaces of enamel, while the dentin microretention was composed of adhesive and hybrid layers with resin tugs in dentin canals. In the second technique, resin tugs were rarely seen and a microgap was dominant along the border of restoration margins. The SEM analysis showed a better marginal adaptation of composite resin to enamel and dentin with better microretention when the etch and rinse adhesive procedure was applied. © 2016 Wiley Periodicals, Inc.

Enamel and dentin bond strength following gaseous ozone application.

PubMed

Cadenaro, Milena; Delise, Chiara; Antoniollo, Francesca; Navarra, Ottavia Chiara; Di Lenarda, Roberto; Breschi, Lorenzo

2009-08-01

To evaluate the effects of gaseous ozone application on enamel and dentin bond strength produced by two self-etching adhesive systems. The shear bond strength test was conducted to assess adhesion on enamel (protocol 1), while the microtensile bond strength test was performed on dentin (protocol 2). Protocol 1: 96 bovine incisors were randomly divided into 4 groups, and enamel surfaces were bonded in accordance with the following treatments: (1E) ozone + Clearfil Protect Bond; (2E) Clearfil Protect Bond (control); (3E) ozone + Xeno III; (4E) Xeno III (control). Ozone gas was applied for 80 s. Shear bond strength was measured with a universal testing machine. Protocol 2: 40 noncarious human molars were selected. Middle/deep dentin was exposed and bonded in accordance with the following treatments: (1D) ozone+Clearfil Protect Bond; (2D) Clearfil Protect Bond (control); (3D) ozone+Xeno III (4D) Xeno III (control). Four-mm-thick buildups were built on the adhesives, then specimens were sectioned in accordance with the nontrimming technique. Specimens were stressed until failure occurred, and failure modes were analyzed. Shear bond and microtensile bond strength data were analyzed using two-way ANOVA and Tukey's post-hoc test. No statistical differences were found between ozone treated specimens and controls, neither on enamel nor on dentin irrespective of the tested adhesive. Clearfil Protect Bond showed higher bond strength to enamel than Xeno III, irrespective of the ozone treatment (p < 0.05). The use of ozone gas to disinfect the cavity before placing a restoration had no influence on immediate enamel and dentin bond strength.

Effect of 2% Chlorhexidine Digluconate on the Bond Strength to Normal versus Caries-Affected Dentin

PubMed Central

Komori, Paula C. P.; Pashley, David H.; Tjäderhane, Leo; Breschi, Lorenzo; Mazzoni, Annalisa; de Goes, Mario Fernando; Wang, Linda; Carrilho, Marcela R.

2013-01-01

SUMMARY This study evaluated the effect of 2% chlorhexidine digluconate (CHX) used as a therapeutic primer on the long-term bond strengths of two etch-and-rinse adhesives to normal (ND) and caries-affected (CAD) dentin. Forty extracted human molars with coronal carious lesions, surrounded by normal dentin, were selected for this study. Flat surfaces of two types of dentin (i.e. ND and CAD) were prepared with a water-cooled high speed diamond disc, and then acid-etched, rinsed and air-dried. In control groups, dentin was re-hydrated with distilled water, blot-dried and bonded with a three-step (Scotchbond Multi-Purpose-MP) or a two-step (Single Bond 2-SB) etch-and-rinse adhesive. In experimental groups, dentin was re-hydrated with 2% CHX (60 s), blot-dried and bonded with the same adhesives. Resin composite build-ups were made. Specimens were prepared for microtensile bond testing in accordance with the non-trimming technique and then tested either immediately or after 6-month storage in artificial saliva. Data were analyzed by ANOVA/Bonferroni tests (α = 0.05). CHX did not affect the immediate bond strength to ND or CAD (p>0.05). CHX treatment significantly lowered the loss of bond strength after 6 months seen in control bonds for ND (p<0.05), but it did not alter the bond strength of CAD (p>0.05). Application of MP on CHX-treated ND or CAD produced bonds that did not change over 6 months of storage. PMID:19363971

Effect of 2% chlorhexidine digluconate on the bond strength to normal versus caries-affected dentin.

PubMed

Komori, Paula C P; Pashley, David H; Tjäderhane, Leo; Breschi, Lorenzo; Mazzoni, Annalisa; de Goes, Mario Fernando; Wang, Linda; Carrilho, Marcela R

2009-01-01

This study evaluated the effect of 2% chlorhexidine digluconate (CHX) used as a therapeutic primer on the long-term bond strengths of two etch-and-rinse adhesives to normal (ND) and caries-affected (CAD) dentin. Forty extracted human molars with coronal carious lesions, surrounded by normal dentin, were selected for this study. The flat surfaces of two types of dentin (ND and CAD) were prepared with a water-cooled high-speed diamond disc, then acid-etched, rinsed and air-dried. In the control groups, the dentin was re-hydrated with distilled water, blot-dried and bonded with a three-step (Scotchbond Multi-Purpose-MP) or two-step (Single Bond 2-SB) etch-and-rinse adhesive. In the experimental groups, the dentin was rehydrated with 2% CHX (60 seconds), blot-dried and bonded with the same adhesives. Resin composite build-ups were made. The specimens were prepared for microtensile bond testing in accordance with the non-trimming technique, then tested either immediately or after six-months storage in artificial saliva. The data were analyzed by ANOVA/Bonferroni tests (alpha = 0.05). CHX did not affect the immediate bond strength to ND or CAD (p > 0.05). CHX treatment significantly lowered the loss of bond strength after six months as seen in the control bonds for ND (p < 0.05), but it did not alter the bond strength of CAD (p > 0.05). The application of MP on CHX-treated ND or CAD produced bonds that did not change over six months of storage.

Effect of handpiece maintenance method on bond strength.

PubMed

Roberts, Howard W; Vandewalle, Kraig S; Charlton, David G; Leonard, Daniel L

2005-01-01

This study evaluated the effect of dental handpiece lubricant on the shear bond strength of three bonding agents to dentin. A lubrication-free handpiece (one that does not require the user to lubricate it) and a handpiece requiring routine lubrication were used in the study. In addition, two different handpiece lubrication methods (automated versus manual application) were also investigated. One hundred and eighty extracted human teeth were ground to expose flat dentin surfaces that were then finished with wet silicon carbide paper. The teeth were randomly divided into 18 groups (n=10). The dentin surface of each specimen was exposed for 30 seconds to water spray from either a lubrication-free handpiece or a lubricated handpiece. Prior to exposure, various lubrication regimens were used on the handpieces that required lubrication. The dentin surfaces were then treated with total-etch, two-step; a self-etch, two-step or a self-etch, one-step bonding agent. Resin composite cylinders were bonded to dentin, the specimens were then thermocycled and tested to failure in shear at seven days. Mean bond strength data were analyzed using Dunnett's multiple comparison test at an 0.05 level of significance. Results indicated that within each of the bonding agents, there were no significant differences in bond strength between the control group and the treatment groups regardless of the type of handpiece or use of routine lubrication.

The effect of immediate dentin sealing and optical powder removal method on the fracture resistance of CAD/CAM-fabricated endocrowns.

PubMed

El-Damanhoury, Hatem M; Gaintantzopoulou, Marianna

2016-01-01

To evaluate the effect of immediate dentin sealing and optical powder removal method on the fracture resistance of CAD/CAM-fabricated ceramic endocrowns. Seventy-eight extracted premolars were endodontically treated. Standardized endocrown preparations were done in 60 teeth. Teeth were divided equally (n = 10) depending on the treatment of dentin (delayed sealing [DS] or immediate sealing [IS]), and the methods of optical powder removal (air-water spray washing [AW]; microabrasion [MA]; or aqueous suspension of pumice [PB], followed by air-water spray washing). After cementation, specimens were thermocycled (5,000 cycles, 5°C/50°C) and stored in distilled water for 1 week. Specimens were loaded in compression using a universal testing machine until failure. Failure load was recorded, and modes of failure were examined under a stereomicroscope. Micromorphological evaluation of different dentin treatments was done under SEM (n = 3). Results were analyzed using two-way ANOVA and Bonferroni post hoc multiple comparison tests (α = 0.05). Fracture resistance of all IS groups was significantly lower than DS groups, except for AW. There was no statistically significant difference between powder removal methods. Immediate dentin sealing does not improve the fracture resistance of endocrown restorations. Air-water spray washing is adequate to remove the optical powder after optical scanning impression taking.

Role of medullary astroglial glutamine synthesis in tooth pulp hypersensitivity associated with frequent masseter muscle contraction.

PubMed

Watase, Tetsuro; Shimizu, Kohei; Ohara, Kinuyo; Komiya, Hiroki; Kanno, Kohei; Hatori, Keisuke; Noma, Noboru; Honda, Kuniya; Tsuboi, Yoshiyuki; Katagiri, Ayano; Shinoda, Masamichi; Ogiso, Bunnai; Iwata, Koichi

2018-01-01

Background The mechanisms underlying tooth pulp hypersensitivity associated with masseter muscle hyperalgesia remain largely underinvestigated. In the present study, we aimed to determine whether masseter muscle contraction induced by daily electrical stimulation influences the mechanical head-withdrawal threshold and genioglossus electromyography activity caused by the application of capsaicin to the upper first molar tooth pulp. We further investigated whether astroglial glutamine synthesis is involved in first molar tooth pulp hypersensitivity associated with masseter muscle contraction. Methods The first molar tooth pulp was treated with capsaicin or vehicle in masseter muscle contraction or sham rats, following which the astroglial glutamine synthetase inhibitor methionine sulfoximine or Phosphate buffered saline (PBS) was applied. Astroglial activation was assessed via immunohistochemistry. Results The mechanical head-withdrawal threshold of the ipsilateral masseter muscle was significantly decreased in masseter muscle contraction rats than in sham rats. Genioglossus electromyography activity was significantly higher in masseter muscle contraction rats than sham rats. Glial fibrillary acidic protein-immunoreactive cell density was significantly higher in masseter muscle contraction rats than in sham rats. Administration of methionine sulfoximine induced no significant changes in the density of glial fibrillary acidic protein-immunoreactive cells relative to PBS treatment. However, mechanical head-withdrawal threshold was significantly higher in masseter muscle contraction rats than PBS-treated rats after methionine sulfoximine administration. Genioglossus electromyography activity following first molar tooth pulp capsaicin treatment was significantly lower in methionine sulfoximine-treated rats than in PBS-treated rats. In the ipsilateral region, the total number of phosphorylated extracellular signal-regulated protein kinase immunoreactive cells in the medullary dorsal horn was significantly smaller upon first molar tooth pulp capsaicin application in methionine sulfoximine-treated rats than in PBS-treated rats. Conclusions Our results suggest that masseter muscle contraction induces astroglial activation, and that this activation spreads from caudal to the obex in the medullary dorsal horn, resulting in enhanced neuronal excitability associated with astroglial glutamine synthesis in medullary dorsal horn neurons receiving inputs from the tooth pulp. These findings provide significant insight into the mechanisms underlying tooth pulp hypersensitivity associated with masseter muscle contraction.

Upregulation of calprotectin in mild IgE-mediated ovalbumin hypersensitivity

PubMed Central

Wang, Junli; Ma, Jingqiu; Sheng, Xiaoyang

2017-01-01

Calprotectin, also known as S100A8/A9, has been linked to gut inflammation caused by IgE-mediated food hypersensitivities, but the pathophysiologic abnormalities it causes remain to be determined. We created a mild food hypersensitivity model through oral gavage of ovalbumin in Norway brown rats without using immune adjuvant. Changes in the levels of calprotectin and inflammation-associated cytokines were then observed over time. We found that fecal calprotectin as well as jejunal and liver TLR4, TNF-α, NF-κB, IL-1β, and IL-6 were upregulated in hypersensitive rats. Additionally, the influence of calprotectin on CD4+ T and dendritic cells was observed by co-culturing CD4+ T cells with dendritic cells, which revealed a shift toward increased Th2 T cells in calprotectin-treated cultures. These results suggest that calprotectin, along with other inflammatory factors, promotes the inflammation seen in mild food allergy. PMID:28454097

Brain damage resembling acute necrotizing encephalopathy as a specific manifestation of haemophagocytic lymphohistiocytosis - induced by hypersensitivity.

PubMed

Dai, Dongling; Wen, Feiqiu; Liu, Sixi; Zhou, Shaoming

2016-08-31

Both haemophagocytic lymphohistiocytosis and acute necrotizing encephalopathy are life-threatening condition. It presents major diagnostic difficulties, since it may have a diversity in clinical picture and with many conditions leading to the same clinical presentation. So it is key important to understand the disorders. We report a pediatric case of haemophagocytic lymphohistiocytosis with specific presentation which predominantly featured as acute necrotizing encephalopathy of childhood. We discuss the diagnosis and differential diagnosis, and speculate the etiology of haemophagocytic lymphohistiocytosis is due to hypersensitivity. Haemophagocytic lymphohistiocytosis and brain damage in this case may be induced by hypersensitivity, which have good clinical outcome if diagnosed and treated early.

Nanodrug delivery systems in dentistry: a review on current status and future perspectives.

PubMed

Renugalakshmi, Apathsakayan; Vinothkumar, Thilla Sekar; Kandaswamy, Deivanayagam

2011-09-01

The present review provides an insight into various potential areas of dentistry that are being invaded by nanotechnology based drugs and drug delivery systems. Current treatments for diseases of dental and oral structures rely on the use of classical pharmacological agents which, in some cases are limited by low efficacy and lack of selectivity to target cells. However, various nanostructures in drug delivery and their challenges in the field of dentistry have not been reviewed so far in the literature. The different treatment opportunities of importance include caries control restorations, tooth remineralisation, management of dentinal hypersensitivity, dental caries vaccine, management of oral biofilm, root canal disinfection, local anaesthesia and periodontal infection. The authors have also identified few dental applications demanding extensive research to emerge as a promising therapeutic strategy. We conclude by claiming that dentistry should follow the trend of probing matter at nanoscale to achieve a predictable treatment outcome.

Cost-effectiveness analysis of HLA B*5701 genotyping in preventing abacavir hypersensitivity.

PubMed

Hughes, Dyfrig A; Vilar, F Javier; Ward, Charlotte C; Alfirevic, Ana; Park, B Kevin; Pirmohamed, Munir

2004-06-01

Abacavir, a human immunodeficiency virus-1 (HIV-1) nucleoside-analogue reverse transcriptase inhibitor, causes severe hypersensitivity in 4-8% of patients. HLA B*5701 is a known genetic risk factor for abacavir hypersensitivity in Caucasians. Our aim was to confirm the presence of this genetic factor in our patients, and to determine whether genotyping for HLA B*5701 would be a cost-effective use of healthcare resources. Patients with and without abacavir hypersensitivity were identified from a UK HIV clinic. Patients were genotyped for HLA B*5701, and pooled data used for calculation of test characteristics. The cost-effectiveness analysis incorporated the cost of testing, cost of treating abacavir hypersensitivity, and the cost and selection of alternative antiretroviral regimens. A probabilistic decision analytic model (comparing testing versus no testing) was formulated and Monte Carlo simulations performed. Of the abacavir hypersensitive patients, six (46%) were HLA B*5701 positive, compared to five (10%) of the non-hypersensitive patients (odds ratio 7.9 [95% confidence intervals 1.5-41.4], P = 0.006). Pooling of our data on HLA B*5701 with published data resulted in a pooled odds ratio of 29 (95% CI 6.4-132.3; P < 0.0001). The cost-effectiveness model demonstrated that depending on the choice of comparator, routine testing for HLA B*5701 ranged from being a dominant strategy (less expensive and more beneficial than not testing) to an incremental cost-effectiveness ratio (versus no testing) of Euro 22,811 per hypersensitivity reaction avoided. Abacavir hypersensitivity is associated with HLA B*5701, and pre-prescription pharmacogenetic testing for this appears to be a cost-effective use of healthcare resources.

Hsa-let-7c controls the committed differentiation of IGF-1-treated mesenchymal stem cells derived from dental pulps by targeting IGF-1R via the MAPK pathways.

PubMed

Liu, Gen-Xia; Ma, Shu; Li, Yao; Yu, Yan; Zhou, Yi-Xiang; Lu, Ya-Die; Jin, Lin; Wang, Zi-Lu; Yu, Jin-Hua

2018-04-13

The putative tumor suppressor microRNA let-7c is extensively associated with the biological properties of cancer cells. However, the potential involvement of let-7c in the differentiation of mesenchymal stem cells has not been fully explored. In this study, we investigated the influence of hsa-let-7c (let-7c) on the proliferation and differentiation of human dental pulp-derived mesenchymal stem cells (DPMSCs) treated with insulin-like growth factor 1 (IGF-1) via flow cytometry, CCK-8 assays, alizarin red staining, real-time RT-PCR, and western blotting. In general, the proliferative capabilities and cell viability of DPMSCs were not significantly affected by the overexpression or deletion of let-7c. However, overexpression of let-7c significantly inhibited the expression of IGF-1 receptor (IGF-1R) and downregulated the osteo/odontogenic differentiation of DPMSCs, as indicated by decreased levels of several osteo/odontogenic markers (osteocalcin, osterix, runt-related transcription factor 2, dentin sialophosphoprotein, dentin sialoprotein, alkaline phosphatase, type 1 collagen, and dentin matrix protein 1) in IGF-1-treated DPMSCs. Inversely, deletion of let-7c resulted in increased IGF-1R levels and enhanced osteo/odontogenic differentiation. Furthermore, the ERK, JNK, and P38 MAPK pathways were significantly inhibited following the overexpression of let-7c in DPMSCs. Deletion of let-7c promoted the activation of the JNK and P38 MAPK pathways. Our cumulative findings indicate that Let-7c can inhibit the osteo/odontogenic differentiation of IGF-1-treated DPMSCs by targeting IGF-1R via the JNK/P38 MAPK signaling pathways.

Anti-inflammatory and anti-hypersensitive effects of the crude extract, fractions and triterpenes obtained from Chrysophyllum cainito leaves in mice.

PubMed

Meira, Nicole Anzanelo; Klein, Luiz Carlos; Rocha, Lilian W; Quintal, Zhelmy Martin; Monache, Franco Delle; Cechinel Filho, Valdir; Quintão, Nara Lins Meira

2014-02-03

Chrysophyllum cainito, popularly known as "star apple", caimito, "abiu-roxo" or "abiu-do-Pará", is a tree of about 25m in height. Besides its culinary use, it is also used in folk medicine for the treatment of diabetes mellitus and several inflammatory diseases. The crude methanolic extract (CME) was submitted to phytochemical studies for obtaining fractions and isolated compounds. They were monitored by thin-layer-chromatography (TLC). The biological activity was evaluated in mice using the carrageenan-induced mechanical hypersensitivity and paw oedema. Biochemical assays, such as myeloperoxidase (MPO) and activity and cytokines levels quantification, were carried out to analyse the involvement of neutrophil migration and IL-1β and TNFα production. Some adverse effects were investigated using the open-field and rota-rod tests, and it was also measured the rectal temperature. This study demonstrates, for the first time, the anti-hypersensitivity and anti-inflammatory effects of CME, fractions and two isolated triterpenes obtained from the leaves of Chrysophyllum cainito on carrageenan-induced hypersensitivity and paw-oedema. The mice treated with CME or chloroform fraction (CHCl3) presented reduction in mechanical hypersensitivity. The effect of the CME seemed to be partially related to the anti-inflammatory activity, as the paw-oedema and MPO activity were also significantly inhibited. The isolated compound Lup-20(29)-en-3β-O-hexanoate demonstrated more reduction of the hypersensitivity than 3β-Lup-20(29)-en-3-yl acetate, suggesting that this molecule might be partially responsible for the biological effects obtained with CME and CHCl3 fractions. Finally, animals treated with CME and CHCl3 did not present changes in locomotor activity, motor performance or body temperature. Our data demonstrates, for the first time, that the crude extract, fractions and pure compounds obtained from the Chrysophyllum cainito leaves possess important anti-hypersensitive properties against inflammatory pain in mice. The mechanisms through which Chrysophyllum cainito exerts its anti-hypersensitive actions are still unclear, and require further investigation; however, this could well constitute a new and attractive alternative for the management of persistent inflammatory and neuropathic pain in humans. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

The variation in surface morphology and hardness of human deciduous teeth samples after laser irradiation

NASA Astrophysics Data System (ADS)

Khalid, Arooj; Bashir, Shazia; Akram, Mahreen; Salman Ahmed, Qazi

2017-11-01

The variation in surface morphology and hardness of human deciduous teeth samples has been investigated after laser irradiation at different wavelengths and energies. Nd:YAG was employed as a source of irradiation for IR (1064 nm) and visible (532 nm) radiation, whereas an excimer laser was used as the source of UV (248 nm) radiation. Scanning electron microscope (SEM) analysis was carried out to reveal the surface morphological evolution of teeth samples. Vickers microhardness tester was employed to investigate the modifications in the hardness of the laser-treated samples. It is observed from SEM analysis that IR wavelength is responsible for ablation of collagen matrix and intertubular dentine. For visible radiation, the ablation of collagen along with hydroxypatite is observed. With UV radiation, the ablation of peritubular dentine is dominant and is responsible for the sealing of tubules. The decrease in hardness at lower energy for both wavelengths is due to the evaporation of carbon content. With increasing energy, evaporation of water along with carbon content, and resolidification and re-organization of inorganic content causes the increase in hardness of the treated dentine. SEM as well as microhardness analyses reveal that laser wavelengths and energy of laser radiation significantly influence the surface morphology and hardness of samples.

Extracellular dextran and DNA affect the formation of Enterococcus faecalis biofilms and their susceptibility to 2% chlorhexidine.

PubMed

Li, Weilan; Liu, Hongyan; Xu, Qiong

2012-07-01

Enterococcus faecalis is frequently recovered from root-filled teeth with refractory apical periodontitis. The ability of E. faecalis to form a matrix-encased biofilm contributes to its pathogenicity; however, the role of extracellular dextran and DNA in biofilm formation and its effect on the susceptibility of the biofilm to chlorhexidine remains poorly understood. E. faecalis biofilms were incubated on dentin blocks. The effect of a dextran-degrading enzyme (dextranase) and DNase I on the adhesion of E. faecalis to dentin was measured using the colony-forming unit (CFU) counting method. CFU assays and confocal laser scanning microscopy were used to investigate the influence of dextranase and DNase I on the antimicrobial activity of 2% chlorhexidine. The CFU count assays indicated that the formation of biofilms by E. faecalis was reduced in cells treated with dextranase or DNase I compared with that in untreated cells (P < .05). In addition, we found that treating E. faecalis biofilms with dextranase or DNase I effectively sensitized the biofilms to 2% chlorhexidine (P < .05). Both dextranase and DNase I decrease the adhesion of E. faecalis to dentin and sensitized E. faecalis biofilms to 2% chlorhexidine. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

High-speed scanning ablation of dental hard tissues with a λ=9.3-μm CO2 laser: heat accumulation and peripheral thermal damage

NASA Astrophysics Data System (ADS)

Nguyen, Daniel; Staninec, Michal; Lee, Chulsung; Fried, Daniel

2010-02-01

A mechanically scanned CO2 laser operated at high laser pulse repetition rates can be used to rapidly and precisely remove dental decay. This study aims to determine whether these laser systems can safely ablate enamel and dentin without excessive heat accumulation and peripheral thermal damage. Peripheral thermal damage can adversely impact the mechanical strength of the irradiated tissue, particularly for dentin, and reduce the adhesion characteristics of the modified surfaces. Samples were derived from noncarious extracted molars. Pulpal temperatures were recorded using microthermocouples situated at the pulp chamber roof of samples (n=12), which were occlusally ablated using a rapid-scanning, water-cooled 300 Hz CO2 laser over a two minute time course. The mechanical strength of facially ablated dentin (n=10) was determined via four-point bend test and compared to control samples (n=10) prepared with 320 grit wet sand paper to simulate conventional preparations. Composite-to-enamel bond strength was measured via single-plane shear test for ablated/non-etched (n=10) and ablated/acid-etched (n=8) samples and compared to control samples (n=9) prepared by 320 grit wet sanding. Thermocouple measurements indicated that the temperature remained below ambient temperature at 19.0°C (s.d.=0.9) if water-cooling was used. There was no discoloration of either dentin and enamel, the treated surfaces were uniformly ablated and there were no cracks observable on the laser treated surfaces. Fourpoint bend tests yielded mean mechanical strengths of 18.2 N (s.d.=4.6) for ablated dentin and 18.1 N (s.d.=2.7) for control (p>0.05). Shear tests yielded mean bond strengths of 31.2 MPa (s.d.=2.5, p<0.01) for ablated/acid-etched samples, 5.2 MPa (s.d.=2.4, p<0.001) for ablated/non-etched samples, and 37.0 MPa (s.d.=3.6) for control. The results indicate that a rapid-scanning 300 Hz CO2 laser can effectively ablate dentin and enamel without excessive heat accumulation and with minimal thermal damage. It is not clear whether the small (16%) but statistically significant reduction in the shear bond strength to enamel is clinically significant since the mean shear bond strength exceeded 30 MPa.

Long-term bonding effectiveness of simplified etch-and-rinse adhesives to dentin after different surface pre-treatments

PubMed Central

Verma, Radhika; Singh, Udai Pratap; Tyagi, Shashi Prabha; Nagpal, Rajni; Manuja, Naveen

2013-01-01

Objective: To evaluate the effect of 2% chlorhexidine (CHX) and 30% proanthocyanidin (PA) application on the immediate and long-term bond strength of simplified etch-and-rinse adhesives to dentin. Materials and Methods: One hundred twenty extracted human molar teeth were ground to expose the flat dentin surface. The teeth were equally divided into six groups according to the adhesives used, either Tetric N Bond or Solobond M and pretreatments given either none, CHX, or PA. Composite cylinder was bonded to each specimen using the respective adhesive technique. Half the samples from each group (n = 10) were then tested immediately. The remaining samples were tested after 6 month storage in distilled water. Results: The mean bond strength of samples was not significantly different upon immediate testing being in the range of 8.4(±0.7) MPa. The bond strength fell dramatically in the control specimens after 6 month storage to around 4.7(±0.33) MPa, while the bond strength was maintained in the samples treated with both CHX and PA. Conclusion: Thirty percent PA was comparable to 2% CHX with respect to preservation of the resin dentin bond over 6 months. PMID:23956543

Tooth quality in dental fluorosis genetic and environmental factors.

PubMed

Vieira, A P G F; Hanocock, R; Eggertsson, H; Everett, E T; Grynpas, M D

2005-01-01

Dental fluorosis (DF) affects the appearance and structure of tooth enamel and can occur following ingestion of excess fluoride during critical periods of amelogenesis. This tooth malformation may, depending on its severity, influence enamel and dentin microhardness and dentin mineralization. Poor correlation between tooth fluoride (F) concentration and DF severity was shown in some studies, but even when a correlation was present, tooth fluoride concentration explained very little of DF severity. This fact calls into question the generally accepted hypothesis that the main factor responsible for DF severity is tooth fluoride concentration. It has been shown previously that genetic factors (susceptibility to DF) play an important role in DF severity although DF severity relates to individual susceptibility to fluoride exposure (genetics), tooth fluoride concentration relates to fluoride ingestion (environmental). The objective of this study was to investigate the correlation between tooth fluoride concentration, DF severity, and tooth mechanical and materials properties. Three strains of mice (previously shown to have different susceptibility to DF) at weaning were treated with four different levels of F in their water (0, 25, 50, and 100 ppm) for 6 weeks. Mice teeth were tested for fluoride by instrumental neutron activation analysis (INAA), DF severity determined by quantitative light-induced fluorescence [QLF], and tooth quality (enamel and dentin microhardness and dentin mineralization). Tooth fluoride concentration (environment factor) correlated positively with DF severity (QLF) (rs=0.608), fluoride treatment group (rs=0.952). However, tooth fluoride concentration correlated negatively with enamel microhardness (rs=-0.587), dentin microhardness (rs=-0.268) and dentin mineralization (rs=-0.245). Dental fluorosis (genetic factor) severity (QLF) correlated positively with fluoride treatment (rs=0.608) and tooth fluoride concentration (rs=0.583). DF severity correlated negatively with enamel microhardness (rs=-0.564) and dentin microhardness (rs=-0.356). Genetic factors (DF severity) and the environmental factor (fluoride concentration in tooth structure) have similar influence on tooth biomechanical properties, whereas only the environmental factor has an influence on tooth material property (mineralization).

Assessment of antibacterial properties of newer dentin bonding agents: An in vitro study.

PubMed

Sampath, Pavitra B; Hegde, Mithra N; Hegde, Priyadarshini

2011-07-01

To evaluate and compare the antibacterial activity of newer dentin bonding agents on Streptococcus mutans using the direct contact test. Streptococcus mutans was used as test organism and a direct contact test was performed. The dentin bonding agents to be tested were grouped as Group I, Clearfil Protect Bond, Group II, Adper Easy One, and Group III, Prime and Bond NT. For the direct contact test, three microtiter plates consisting of 96 wells each were taken (288 wells). These wells were divided into three groups of 96 wells; 16 wells of a microtiter plate were utilized, of which four were designated as 'A' wells (with the dentin bonding agent and bacterial suspension), another four as 'B' wells (without the dentin bonding agent, but with the bacterial suspension), another four as the 'C' wells (with the tested material, but without bacteria, which served as the negative control), and the remaining four as the 'D' wells (without the dentin bonding agent, which served as the positive control). Each group was treated with their respective bonding agents as per the manufactures instructions. Broth of 15 μL was then transferred from the A wells into an adjacent set of B wells containing fresh medium (215 μL). This resulted in two sets of four wells for each tested material containing an equal volume of liquid medium, so that bacterial growth was monitored both in the presence and in the absence of the tested material. The plate was placed for incubation at 37°C in the microplate reader and the optical density in each well was measured at 600 nm. The readings were taken at regular intervals. (Every 30 minutes for 16 hours). The Dentin bonding agents evaluated in this study showed different inhibitory effects. Clearfil Protect Bond and Prime and Bond NT were most effective, and Adper Easy One was least effective against Streptococcus mutans. The Dentin bonding agents evaluated in this study showed different inhibitory effects. Clearfil Protect Bond and Prime and Bond NT were most effective, and Adper Easy One was the least effective against Streptococcus mutans. Hence, the incorporation of antibacterial agents into the dentin bonding agents may become an essential factor in inhibiting residual bacteria in the cavity and secondary caries.

The effect of dimethyl sulfoxide (DMSO) on dentin bonding and nanoleakage of etch-and-rinse adhesives.

PubMed

Tjäderhane, Leo; Mehtälä, Pekka; Scaffa, Polliana; Vidal, Cristina; Pääkkönen, Virve; Breschi, Lorenzo; Hebling, Josimeri; Tay, Franklin R; Nascimento, Fabio D; Pashley, David H; Carrilho, Marcela R

2013-10-01

The objective was to examine the effect of a solvent dimethyl sulfoxide (DMSO) on resin-dentin bond durability, as well as potential functional mechanisms behind the effect. Microtensile bond strength (μTBS) was evaluated in extracted human teeth in two separate experiments. Dentin specimens were acid-etched and assigned to pre-treatment with 0.5mM (0.004%) DMSO as additional primer for 30s and to controls with water pre-treatment. Two-step etch-and-rinse adhesive (Scotchbond 1XT, 3M ESPE) was applied and resin composite build-ups were created. Specimens were immediately tested for μTBS or stored in artificial saliva for 6 and 12 months prior to testing. Additional immediate and 6-month specimens were examined for interfacial nanoleakage analysis under SEM. Matrix metalloproteinase (MMP) inhibition by DMSO was examined with gelatin zymography. Demineralized dentin disks were incubated in 100% DMSO to observe the optical clearing effect. The use of 0.5mM DMSO had no effect on immediate bond strength or nanoleakage. In controls, μTBS decreased significantly after storage, but increased significantly in DMSO-treated group. The control group had significantly lower μTBS than DMSO-group after 6 and 12 months. DMSO also eliminated the increase in nanoleakage seen in controls. 5% and higher DMSO concentrations significantly inhibited the gelatinases. DMSO induced optical clearing effect demonstrating collagen dissociation. DMSO as a solvent may be useful in improving the preservation of long-term dentin-adhesive bond strength. The effect may relate to dentinal enzyme inhibition or improved wetting of collagen by adhesives. The collagen dissociation required much higher DMSO concentrations than the 0.5mM DMSO used for bonding. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Influence of Smear Layer on the Antimicrobial Activity of a Sodium Hypochlorite/Etidronic Acid Irrigating Solution in Infected Dentin.

PubMed

Morago, Ana; Ordinola-Zapata, Ronald; Ferrer-Luque, Carmen María; Baca, Pilar; Ruiz-Linares, Matilde; Arias-Moliz, María Teresa

2016-11-01

The aim of this study was to evaluate the influence of the smear layer on the antimicrobial activity of a 2.5% sodium hypochlorite (NaOCl)/9% etidronic acid (HEBP) irrigating solution against bacteria growing inside dentin tubules. Dentin tubules were infected with Enterococcus faecalis by centrifugation. After 5 days of incubation, the smear layer had formed in half of the samples, which were then treated with 2.5% NaOCl either alone or combined with 9% HEBP for 3 minutes. The percentage of dead cells in infected dentinal tubules was measured using confocal laser scanning microscopy and the live/dead technique. The smear layer on the surface of the root canal wall was also observed by scanning electron microscopy. Results of the percentage of dead cells were compared using parametric tests after subjecting data to the normalized Anscombe transformation. The level of significance was P < .05. In the absence of the smear layer, 2.5% NaOCl alone and combined with 9% HEBP showed high antimicrobial activity without significant differences between the 2. The smear layer reduced the antimicrobial activity of 2.5% NaOCl significantly, whereas the solution with HEBP was not affected. No dentin tubules free of the smear layer were obtained in the 2.5% NaOCl group. In the case of 2.5% NaOCl/9% HEBP, 95.40% ± 3.63% of dentin tubules were cleaned. The presence of the smear layer reduced the antimicrobial activity of 2.5% NaOCl. The combination of 2.5% NaOCl/9% HEBP exerted antimicrobial activity that was not reduced by the smear layer. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Effect of a single application of TiF(4) and NaF varnishes and solutions on dentin erosion in vitro.

PubMed

Magalhães, Ana Carolina; Levy, Flávia Mauad; Rios, Daniela; Buzalaf, Marília Afonso Rabelo

2010-02-01

This in vitro study aimed to analyse the effect of a single application of TiF(4) and NaF varnishes and solutions to protect against dentin erosion. Bovine root dentin samples were pre-treated with NaF-Duraphat varnish (2.26%F, pH 4.5), NaF/CaF(2)-Duofluorid varnish (5.63%F, pH 8.0), NaF-experimental varnish (2.45%F, pH 4.5), TiF(4)-experimental varnish (2.45%F, pH 1.2), NaF solution (2.26%F, pH 4.5), TiF(4) solution (2.45%F, pH 1.2) and placebo varnish (pH 5.0, no-F varnish control). Controls remained untreated. Ten samples in each group were then subjected to an erosive demineralisation (Sprite Zero, 4x 90s/day) and remineralisation (artificial saliva, between the erosive cycles) cycling for 5 days. Dentin loss was measured profilometrically after pre-treatment and after 1, 3 and 5 days of de-remineralisation cycling. The data were statistically analysed by two-way ANOVA and Bonferroni's post hoc test (p<0.05). After pre-treatment, TiF(4) solution significantly induced surface loss (1.08+/-0.53 microm). Only Duraphat reduced the dentin loss overtime, but it did not significantly differ from placebo varnish (at 3rd and 5th days) and TiF(4) varnish (at 3rd day). Duraphat varnish seems to be the best option to partially reduce dentin erosion. However, the maintenance of the effects of this treatment after successive erosive challenges is limited. Copyright 2009 Elsevier Ltd. All rights reserved.

Effect of tooth whitening strips on fatigue resistance and flexural strength of bovine dentin in vitro

PubMed Central

Kim, Namhee; De Souza, Grace M.

2017-01-01

Objective To determine the effects of whitening strips on bovine dentin fatigue resistance and flexural strength in vitro. Materials and methods A total of eighty bovine dentin specimens (2x2x17mm) were treated with either: control glycerine gel on plastic film wrap or whitening strips containing 9.5% hydrogen peroxide. Treatment was applied for 30 minutes, twice a day, for 1- or 4-weeks. After the last treatment, ten specimens per group were randomly selected to undergo fatigue testing (106 cycles, 3Hz, 20N) while the other ten were subjected to flexural strength testing after ten days of storage in artificial saliva. Kaplan-Meier method with a log rank test, Wilcoxon test and Cox regression were used to assess fatigue test results (p<0.05). One-way ANOVA and Tukey’s tests were used to compare the flexural strength results (p<0.05). Results There were significant differences in survival during the fatigue test among the groups (p<0.001). Treatment (control or bleach) was a significant factor for specimen survival (p<0.001, Exp(B) = 33.45). There were significant differences in mean flexural strength (p<0.001). No significant difference was found between “1-wk control” and “4-wk control”. The mean flexural strength and fatigue resistance of the “4-wk bleach” were significantly lower than all the other groups. Conclusions The use of whitening strips reduced the fatigue resistance and flexural strength of bovine dentin in vitro. Until the effect of whitening strips on mechanical properties of human dentin is fully elucidated, it remains prudent to advise patients to avoid excessive direct use of whitening strips on dentin. PMID:28278191

Starch Combined with Sucrose Provokes Greater Root Dentine Demineralization than Sucrose Alone.

PubMed

Souza, Samilly Evangelista; Sampaio, Aline Araújo; Del Bel Cury, Altair Antoninha; Cavalcanti, Yuri Wanderley; Ricomini Filho, Antônio Pedro; Cury, Jaime Aparecido

2018-02-14

Since there is no consensus about whether starch increases the cariogenic potential of sucrose, we used a validated 3-species biofilm model to evaluate if starch combined with sucrose provokes higher root dentine demineralization than sucrose alone. Biofilms (n = 18) composed by Streptococcus mutans (the most cariogenic bacteria), Actinomces naeslundii (which has amylolytic activity), and Streptococcus gordonii (which binds salivary amylase) were formed on root dentine slabs under exposure 8 ×/day to one of the following treatments: 0.9% NaCl, 1% starch, 10% sucrose, or a combination of 1% starch and 10% sucrose. Before each treatment, biofilms were pretreated with human whole saliva for 1 min. The pH of the culture medium was measured daily as an indicator of biofilm acidogenicity. After 96 h of growth, the biofilms were collected, and the biomass, bacteria viability, and polysaccharides were analyzed. Dentine demineralization was assessed by surface hardness loss (% SHL). Biofilm bioarchitecture was analyzed using confocal laser scanning microscopy. Treatment with a starch and sucrose combination provoked higher (p = 0.01) dentine demineralization than sucrose alone (% SHL = 53.2 ± 7.0 vs. 43.2 ± 8.7). This was supported by lower pH values (p = 0.007) of the culture medium after daily exposure to the starch and sucrose combination compared with sucrose (4.89 ± 0.29 vs. 5.19 ± 0.32). Microbiological and biochemical findings did not differ between biofilms treated with the combination of starch and sucrose and sucrose alone (p > 0.05). Our findings give support to the hypothesis that a starch and sucrose combination is more cariogenic for root dentine than sucrose alone. © 2018 S. Karger AG, Basel.

Characterization of caries progression on dentin after irradiation with Nd:YAG laser by FTIR spectroscopy and fluorescence imaging

NASA Astrophysics Data System (ADS)

Ana, P. A.; Brito, A. M. M.; Zezell, D. M.; Lins, E. C. C. C.

2015-06-01

Considering the use of high intensity lasers for preventing dental caries, this blind in vitro study evaluated the compositional and fluorescence effects promoted by Nd:YAG laser (λ=1064 nm) when applied for prevention of progression of dentin caries, in association or not with topical application of acidulated phosphate fluoride (APF). Sixty bovine root dentin slabs were prepared and demineralized by 32h in order to create early caries lesions. After, the slabs were distributed into six experimental groups: G1- untreated and not submitted to a pH-cycling model; G2- untreated and submitted to a pH-cycling model; G3- acidulated phosphate fluoride application (APF); G4- Nd:YAG irradiation (84.9 J/cm2, 60 mJ/pulse); G5- treated with Nd:YAG+APF; G6- treated with APF+Nd:YAG. After treatments, the samples of groups G2 to G6 were submitted to a 4-day pH-cycling model in order to simulate the progression of early caries lesions. All samples were characterized by the micro-attenuated total reflection technique of Fourier transformed infrared spectroscopy (μATR-FTIR), using a diamond crystal, and by a fluorescence imaging system (FIS), in which it was used an illuminating system at λ= 405±30 nm. Demineralization promoted reduction in carbonate and phosphate contents, exposing the organic matter; as well, it was observed a significant reduction of fluorescence intensity. Nd:YAG laser promoted additional chemical changes, and increased the fluorescence intensity even with the development of caries lesions. It was concluded that the compositional changes promoted by Nd:YAG, when associated to APF, are responsible for the reduction of demineralization progression observed on root dentin.

Restorative therapy for erosive lesions.

PubMed

Lambrechts, P; Van Meerbeek, B; Perdigão, J; Gladys, S; Braem, M; Vanherle, G

1996-04-01

More needs to be learned about the etiology of erosion lesions before they can be accurately diagnosed, confidently treated and, more importantly, prevented. The treatment is dependent on the location and the degree of erosion. The decision to treat an erosion lesion should be based on careful consideration of the etiology and progression of the condition. Reasons for restoring noncarious enamel/dentin lesions are discussed and various therapeutic measures are provided. Preventive and restorative therapeutic measures for noncarious abrasive/ erosive lesions are proposed such as: a change of dietary or behavior patterns; application of desensitization products; intensive fluoride therapy with or without iontophoresis; brushing with desensitizing dentifrices; adhesive penetration with dentin bonding agents; glass ionomers and compomers; resin composites; composite or porcelain veneers; crown and bridge work; occlusal adjustments and nightguard fabrication if the abfraction factor coincides. The clinical durability of restorative therapy and important clinical factors related to the restoration of multifactorial defects are discussed.

FcγRIIa ligation induces platelet hypersensitivity to thrombotic stimuli.

PubMed

Berlacher, Mark D; Vieth, Joshua A; Heflin, Brittany C; Gay, Steven R; Antczak, Adam J; Tasma, Brian E; Boardman, Holly J; Singh, Navinderjit; Montel, Angela H; Kahaleh, M Bashar; Worth, Randall G

2013-01-01

Platelets are known for their important role in hemostasis, however their significance in other functions, including inflammation and infection, are becoming more apparent. Patients with systemic lupus erythematosus (SLE) are known to have circulating IgG complexes in their blood and are highly susceptible to thrombotic events. Because platelets express a single receptor for IgG, we tested the hypothesis that ligation of this receptor (FcγRIIa) induces platelet hypersensitivity to thrombotic stimuli. Platelets from SLE patients were considerably more sensitive to thrombin compared to healthy volunteers, and this correlated with elevated levels of surface IgG on SLE platelets. To test whether FcγRIIa ligation stimulated thrombin hypersensitivity, platelets from healthy volunteers were incubated with buffer or heat-aggregated IgG, then stimulated with increasing concentrations of thrombin. Interestingly, heat-aggregated IgG-stimulated platelets, but not buffer-treated platelets, were hypersensitive to thrombin, and hypersensitivity was blocked by an anti-FcγRIIa monoclonal antibody (mAb). Thrombin hypersensitivity was not due to changes in thrombin receptor expression (GPIbα or PAR1) but is dependent on activation of shared signaling molecules. These observations suggest that ligation of platelet FcγRIIa by IgG complexes induces a hypersensitive state whereby small changes in thrombotic stimuli may result in platelet activation and subsequent vascular complications such as transient ischemic attacks or stroke. Copyright © 2013 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Antimicrobial Photodynamic Therapy as an Adjunct for Clinical Partial Removal of Deciduous Carious Tissue: A Minimally Invasive Approach.

PubMed

Ornellas, Pâmela O; Antunes, Leonardo S; Motta, Paula C; Mendonça, Caroline; Póvoa, Helvécio; Fontes, Karla; Iorio, Natalia; Antunes, Lívia A A

2018-06-20

This study aimed to evaluate the use of antimicrobial photodynamic therapy (aPDT) as an adjunct for minimally invasive treatment (partial removal of carious tissue - PRCT) of deciduous carious tissue evaluating its efficacy in reducing microorganisms. For that, a clinical study was design including children with deciduous molars with active deep caries lesions (DCL). PRCT was performed and remaining dentin was treated with 100 μg/mL methylene blue solution (5 min) and than irradiated with a low power laser emitting red light (InGaAIP - indium gallium aluminum phosphide; λ = 660nm; 100mW; 300 J/cm²; 90s; 9J). The colony forming units (CFU) count after PRCT and after PRCT + aPDT/mg of dentin were compared for total microorganisms, including Candida spp., the mutans streptococci group, Streptococcus spp. and Lactobacillus spp. The dentin was classified (color, consistency and humidity). The microbial reduction varied from 69.88% to 86.29% and was significantly observed for total microorganisms, mutans streptococci, Streptococcus spp. and Lactobacillus spp (p<0.001). The dentin type did not influence reduction of microorganisms (p>0.05). The aPDT presents a promising future for clinical use as an adjunct for the reduction of microorganisms in PRCT of DCL in all kinds of dentin. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Use of patch testing for the diagnosis of abacavir-related hypersensitivity reaction in HIV patients.

PubMed

Giorgini, S; Martinelli, C; Tognetti, L; Carocci, A; Giuntini, R; Mastronardi, V; Torricelli, F; Leoncini, F; Lotti, T

2011-01-01

The use of antiretroviral drug abacavir (ABC) has been often associated with cutaneous hypersensitivity reactions, the majority being severe. The present study discusses the issues of patch testing associated with pharmacogenetic screening in light of the development of abacavir hypersensitivity reactions (HSRs). The present authors classified 100 patients into three groups: 20 patients (group A) had experienced a hypersensitivity reaction when treated with highly active antiretroviral therapy (HAART) including ABC; 60 HIV-positive patients (group B) were receiving HAART scheme including ABC; 20 HIV-negative patients acted as control group (group C). Patients of group A and B were patch tested with ABC as such, then with an ABC extract diluted to 1 and 10% in petrolatum. Group C patients underwent patches with petrolatum only. A biopsy of the lesion was performed in those patients who showed a positive skin reaction. All patients had been tested for HLA-B5701. A correlation between positive ABC-patch testing and HLA-B5701 was found in 50% of patients enrolled in group A, while in group B and C, all patients tested negative for both genetic marker and ABC-patch testing. Histopathology findings confirmed a vigorous CD4+ and CD8+ cellular response that is compatible with HSR. Patch testing is a safe and sensitive method that can be used for to confirm or exclude any correlation between abacavir and hypersensitivity skin reactions in patients who have been previously treated with abacavir during HAART. Correlation between patch test, immunohistochimical, and genetic tests results shows that genetic testing increases the possibility to identify patients with a true reaction. © 2012 Wiley Periodicals, Inc.

Impact of Prophylactic Conversion to an Extended Infusion Schedule to Prevent Hypersensitivity Reactions in Ovarian Cancer Patients during Carboplatin Retreatment

PubMed Central

O’Cearbhaill, Roisin; Zhou, Qin; Iasonos, Alexia; Hensley, Martee L.; Tew, William P.; Aghajanian, Carol; Spriggs, David R.; Lichtman, Stuart M.; Sabbatini, Paul J.

2015-01-01

Objective Repeated exposure to carboplatin can lead to hypersensitivity reactions during retreatment with carboplatin. This may prevent its further use in platinum-sensitive ovarian cancer patients. At our institution, an increasing proportion of patients are prophylactically converted to an extended schedule of infusion after 8 cycles of carboplatin. We sought to determine whether an incrementally increasing, extended 3-hour infusion of carboplatin was associated with a lower rate of hypersensitivity reactions compared to the standard 30-minute schedule in sequentially treated patients. Methods We performed a retrospective electronic medical record review of patients with recurrent ovarian cancer retreated with carboplatin at our institution from 01/98–12/08. Results Seven hundred seventy-seven patients with relapsed ovarian, fallopian tube, or primary peritoneal cancer were retreated with carboplatin and met study inclusion criteria. Of these, 117 (17%) developed hypersensitivity reactions during second-line or greater carboplatin-based treatment for recurrent disease. Only 6 (3.4%) of the 174 patients who received the extended schedule developed hypersensitivity reactions (0% grade 4; 1.7% grade 3) compared to 111 (21%) of 533 patients in the standard schedule group (12% grade 4; 77% grade 3). The first hypersensitivity episode occurred after a median of 16 platinum (carboplatin and cisplatin) treatments in the extended group compared to 9 in the standard group. Using the Fisher-exact test, there was an association with a reduced incidence of hypersensitivity reactions with the extended infusion schedule (P<0.001). Conclusion Our data suggest appropriate premedication and prophylactic conversion to an extended infusion during carboplatin retreatment may reduce hypersensitivity reactions. PMID:19944454

Estimation of the risk of failure for an endodontically treated maxillary premolar with MODP preparation and CAD/CAM ceramic restorations.

PubMed

Lin, Chun-Li; Chang, Yen-Hsiang; Pa, Che-An

2009-10-01

This study evaluated the risk of failure for an endodontically treated premolar with mesio occlusodistal palatal (MODP) preparation and 3 different computer-aided design/computer-aided manufacturing (CAD/CAM) ceramic restoration configurations. Three 3-dimensional finite element (FE) models designed with CAD/CAM ceramic onlay, endocrown, and conventional crown restorations were constructed to perform simulations. The Weibull function was incorporated with FE analysis to calculate the long-term failure probability relative to different load conditions. The results indicated that the stress values on the enamel, dentin, and luting cement for endocrown restoration were the lowest values relative to the other 2 restorations. Weibull analysis revealed that the individual failure probability in the endocrown enamel, dentin, and luting cement obviously diminished more than those for onlay and conventional crown restorations. The overall failure probabilities were 27.5%, 1%, and 1% for onlay, endocrown, and conventional crown restorations, respectively, in normal occlusal condition. This numeric investigation suggests that endocrown and conventional crown restorations for endodontically treated premolars with MODP preparation present similar longevity.

Immediate-type hypersensitivity drug reactions

PubMed Central

Stone, Shelley F; Phillips, Elizabeth J; Wiese, Michael D; Heddle, Robert J; Brown, Simon G A

2014-01-01

Hypersensitivity reactions including anaphylaxis have been reported for nearly all classes of therapeutic reagents and these reactions can occur within minutes to hours of exposure. These reactions are unpredictable, not directly related to dose or the pharmacological action of the drug and have a relatively high mortality risk. This review will focus on the clinical presentation, immune mechanisms, diagnosis and prevention of the most serious form of immediate onset drug hypersensitivity reaction, anaphylaxis. The incidence of drug-induced anaphylaxis deaths appears to be increasing and our understanding of the multiple and complex reasons for the unpredictable nature of anaphylaxis to drugs is also expanding. This review highlights the importance of enhancing our understanding of the biology of the patient (i.e. immune response, genetics) as well as the pharmacology and chemistry of the drug when investigating, diagnosing and treating drug hypersensitivity. Misdiagnosis of drug hypersensitivity leads to substantial patient risk and cost. Although oral provocation is often considered the gold standard of diagnosis, it can pose a potential risk to the patient. There is an urgent need to improve and standardize diagnostic testing and desensitization protocols as other diagnostic tests currently available for assessment of immediate drug allergy are not highly predictive. PMID:24286446

Immediate-type hypersensitivity drug reactions.

PubMed

Stone, Shelley F; Phillips, Elizabeth J; Wiese, Michael D; Heddle, Robert J; Brown, Simon G A

2014-07-01

Hypersensitivity reactions including anaphylaxis have been reported for nearly all classes of therapeutic reagents and these reactions can occur within minutes to hours of exposure. These reactions are unpredictable, not directly related to dose or the pharmacological action of the drug and have a relatively high mortality risk. This review will focus on the clinical presentation, immune mechanisms, diagnosis and prevention of the most serious form of immediate onset drug hypersensitivity reaction, anaphylaxis. The incidence of drug-induced anaphylaxis deaths appears to be increasing and our understanding of the multiple and complex reasons for the unpredictable nature of anaphylaxis to drugs is also expanding. This review highlights the importance of enhancing our understanding of the biology of the patient (i.e. immune response, genetics) as well as the pharmacology and chemistry of the drug when investigating, diagnosing and treating drug hypersensitivity. Misdiagnosis of drug hypersensitivity leads to substantial patient risk and cost. Although oral provocation is often considered the gold standard of diagnosis, it can pose a potential risk to the patient. There is an urgent need to improve and standardize diagnostic testing and desensitization protocols as other diagnostic tests currently available for assessment of immediate drug allergy are not highly predictive. © 2013 The British Pharmacological Society.

Metronidazole hypersensitivity.

PubMed

Knowles, S; Choudhury, T; Shear, N H

1994-03-01

To report a case of a possible hypersensitivity reaction induced by metronidazole. An Asian woman with a history of recurrent vaginitis had previously developed localized erythema while on intravaginal metronidazole and nystatin. While receiving oral metronidazole for treatment of a current bacterial vaginosis, she developed chills, fever, generalized erythema, and a rash within 60 minutes of the first dose. Treatment with diphenhydramine was instituted. The following day while in the hospital, the patient's condition worsened; she experienced shortness of breath and increased edema of the extremities. Methylprednisolone was administered with diphenhydramine and her condition improved over the next 5 days. The patient's vaginitis was treated with gentian violet and she was discharged on a tapering dosage of prednisone. Metronidazole-induced cutaneous reactions and systemic hypersensitivity reactions are reviewed. Alternatives to metronidazole and other potential cross-reactive drugs are suggested for the treatment of recurrent vaginitis. Although the patient's initial reaction to metronidazole represented a rare event, written documentation and communication in the patient's native language may have prevented the subsequent severe hypersensitivity reaction.

Selective removal of carious human dentin using a nanosecond pulsed laser operating at a wavelength of 5.85 μ m

NASA Astrophysics Data System (ADS)

Ishii, Katsunori; Kita, Tetsuya; Yoshikawa, Kazushi; Yasuo, Kenzo; Yamamoto, Kazuyo; Awazu, Kunio

2015-05-01

Less invasive methods for treating dental caries are strongly desired. However, conventional dental lasers do not always selectively remove caries or ensure good bonding to the composite resin. According to our previous study, demineralized dentin might be removed by a nanosecond pulsed laser operating at wavelengths of around 5.8 μm. The present study investigated the irradiation effect of the light on carious human dentin classified into "remove," "not remove," and "unclear" categories. Under 5.85-μm laser pulses, at average power densities of 30 W/cm2 and irradiation time of 2 s, the ablation depth of "remove" and "not remove," and also the ablation depth of "unclear" and "not remove," were significantly different (p<0.01). The ablation depth was correlated with both Vickers hardness and Ca content. Thus, a nanosecond pulsed laser operating at 5.85 μm proved an effective less-invasive caries treatment.

Effect of different irrigation on smear layer removal after post space preparation.

PubMed

Gu, Xin-Hua; Mao, Cai-Yun; Kern, Matthias

2009-04-01

The purpose of this study was to evaluate the effect of different irrigating solutions on smear layer removal and dentinal tubule opening on root canal surfaces after post space preparation and to study whether additional ultrasonic irrigation has any effect on smear layer removal. Forty-eight anterior teeth were treated endodontically. After post space preparation, they were assigned to six groups: group 1, EDTA; group 2, EDTA with ultrasonic activation; group 3, sodium hypochlorite (NaOCl); group 4, NaOCl with ultrasonic activation; group 5, sodium chloride (NaCl); and group 6, NaCl with ultrasonic activation. Specimens were examined under a field-emission scanning electron microscope and scored for debris removal and dentinal tubule opening at the coronal, middle, and apical thirds of the root canal. The results showed that EDTA performed significantly better than NaCl and NaOCl in smear layer removal and dentinal tubule opening. Additional ultrasonic irrigation did not improve smear layer removal significantly.

Determination of the bactericidal activity of different calcium hydroxide presentations on a dentin model.

PubMed

Sinan, A; Adou, A J; Rochd, T; Calas, P

2007-03-01

Calcium hydroxide placed as a temporary dressing in the root canal helps sterilize infected canals. Hycal and Roeko calcium hydroxide points are two delayed-action medications containing Ca(OH)2 recommended for root canal treatment. The purpose of this study was to test their bactericidal activity in comparison with that of C-PMCP on Streptococcus sanguins strain NCTC 7823. Artificially infected 4-mm high blocks of dentin obtained from bovine incisors were used as an experimental model (n = 192). After three days of treatment with the two antiseptics, intracanal dentin powder was collected by serial drillings and used to inoculate a culture broth. The turbidity of this broth after 24 hours showed if the bacteria were eliminated or not and was used as criterion of antiseptic efficacy. No bacterial growth was observed in the samples treated with C-PMCP. Hycal had a considerable bactericidal activity with 94% of negative cultures whereas first-generation Roeko points had no activity on the strain of S. sanguis tested.

Effects of etch-and-rinse and self-etch adhesives on dentin MMP-2 and MMP-9.

PubMed

Mazzoni, A; Scaffa, P; Carrilho, M; Tjäderhane, L; Di Lenarda, R; Polimeni, A; Tezvergil-Mutluay, A; Tay, F R; Pashley, D H; Breschi, L

2013-01-01

Auto-degradation of collagen matrices occurs within hybrid layers created by contemporary dentin bonding systems, by the slow action of host-derived matrix metalloproteinases (MMPs). This study tested the null hypothesis that there are no differences in the activities of MMP-2 and -9 after treatment with different etch-and-rinse or self-etch adhesives. Tested adhesives were: Adper Scotchbond 1XT (3M ESPE), PQ1 (Ultradent), Peak LC (Ultradent), Optibond Solo Plus (Kerr), Prime&Bond NT (Dentsply) (all 2-step etch-and-rinse adhesives), and Adper Easy Bond (3M ESPE), Tri-S (Kuraray), and Xeno-V (Dentsply) (1-step self-etch adhesives). MMP-2 and -9 activities were quantified in adhesive-treated dentin powder by means of an activity assay and gelatin zymography. MMP-2 and MMP-9 activities were found after treatment with all of the simplified etch-and-rinse and self-etch adhesives; however, the activation was adhesive-dependent. It is concluded that all two-step etch-and-rinse and the one-step self-etch adhesives tested can activate endogenous MMP-2 and MMP-9 in human dentin. These results support the role of endogenous MMPs in the degradation of hybrid layers created by these adhesives.

Thermal effects associated with the Nd/YAG dental laser.

PubMed

von Fraunhofer, J A; Allen, D J

1993-01-01

The heat produced at the dentinal pulpal wall opposite the irradiation site was measured during etching of dental enamel with an Nd:YAG laser in preparation for direct bonding of orthodontic appliances. Forty extracted human teeth were randomly divided into four groups of 10 teeth. Within each group, the buccal surfaces of 5 teeth and the lingual surfaces of the other 5 teeth were laser treated for 12 sec. Irradiation was performed with a commercial Nd:YAG laser at the power settings of 80mJ, 1W, 2W and 3W. Prior to irradiation, an occlusal access preparation was made into the pulp in order to facilitate the placement of a thermocouple for measurement of temperature changes at the dentinal pulpal wall opposite the irradiation site. The thermocouple was held against the dentinal pulpal wall and the resulting temperature changes were recorded. Heating effects at the dentinal pulpal wall on both buccal and lingual surfaces showed an increase in heat as a function of the increase in power output from the laser unit (p < 0.01). The temperatures measured at power levels 1-3W appeared to be of sufficient magnitude to cause at least localized pulpal inflammation and possible irreversible damage to the pulp tissue immediately opposite the site of laser irradiation.

Effects of Etch-and-Rinse and Self-etch Adhesives on Dentin MMP-2 and MMP-9

PubMed Central

Mazzoni, A.; Scaffa, P.; Carrilho, M.; Tjäderhane, L.; Di Lenarda, R.; Polimeni, A.; Tezvergil-Mutluay, A.; Tay, F.R.; Pashley, D.H.; Breschi, L.

2013-01-01

Auto-degradation of collagen matrices occurs within hybrid layers created by contemporary dentin bonding systems, by the slow action of host-derived matrix metalloproteinases (MMPs). This study tested the null hypothesis that there are no differences in the activities of MMP-2 and -9 after treatment with different etch-and-rinse or self-etch adhesives. Tested adhesives were: Adper Scotchbond 1XT (3M ESPE), PQ1 (Ultradent), Peak LC (Ultradent), Optibond Solo Plus (Kerr), Prime&Bond NT (Dentsply) (all 2-step etch-and-rinse adhesives), and Adper Easy Bond (3M ESPE), Tri-S (Kuraray), and Xeno-V (Dentsply) (1-step self-etch adhesives). MMP-2 and -9 activities were quantified in adhesive-treated dentin powder by means of an activity assay and gelatin zymography. MMP-2 and MMP-9 activities were found after treatment with all of the simplified etch-and-rinse and self-etch adhesives; however, the activation was adhesive-dependent. It is concluded that all two-step etch-and-rinse and the one-step self-etch adhesives tested can activate endogenous MMP-2 and MMP-9 in human dentin. These results support the role of endogenous MMPs in the degradation of hybrid layers created by these adhesives. PMID:23128110

An in situ investigation into the abrasion of eroded dental hard tissues by a whitening dentifrice.

PubMed

Turssi, C P; Faraoni, J J; Rodrigues, A L; Serra, M C

2004-01-01

This crossover study aimed to investigate abrasion of previously eroded hard dental tissues by a whitening dentifrice compared to a regular dentifrice. After a 3-day lead-in period, 14 volunteers were randomly assigned to use one of the toothpastes while wearing a removable appliance, containing 3 enamel and 3 root dentine slabs on each side. On the first day salivary pellicle was allowed to form. Twice daily for the following 3 days, one side of each appliance was immersed in an acidic carbonated drink ex vivo while the other side remained unexposed. Specimens were then brushed with the allocated dentifrice. After a 3-day washout period, new sets of enamel and dentine slabs were mounted in the appliances and the participants commenced period 2 using the alternative toothpaste. Acid-treated specimens always showed more wear than untreated specimens. The whitening dentifrice did not significantly increase the wear of softened enamel compared with the regular dentifrice. Brushing with the whitening toothpaste led to significantly greater wear of sound enamel and of both eroded and sound dentine than the regular dentifrice. The results suggest that whitening dentifrices may not increase the wear of acid-softened enamel but may have a more deleterious effect on dentine than regular toothpastes.

Drug hypersensitivity in human immunodeficiency virus-infected patient: challenging diagnosis and management

PubMed Central

Widhani, Alvina; Karjadi, Teguh Harjono

2014-01-01

Human immunodeficiency virus (HIV)-infected patients present complex immunological alterations. Multiple drugs that usually prescribed for prevention or treatment of opportunistic infections and antiretroviral pose these patients a higher risk of developing drug hypersensitivity. All antiretroviral agents and drugs to treat opportunistic infections have been reported to cause drug hypersensitivity reactions. Allergic reactions with antiretroviral are not restricted to older agents, although newer drugs usually more tolerated. Cutaneous adverse drug reactions are the most common manifestation of drug hypersensitivity in HIV, typically manifesting as maculopapular rash with or without systemic symptoms in the presence or absence of internal organ involvement. The onset of an allergic reaction is usually delayed. Severe drug hypersensitity reactions as erythema multiforme, Stevens Johnson syndrome and toxic epidermal necrolysis develop more often in HIV-infected patients compared to other populations. Mild to moderate rash without systemic symptom or organ involvement usually do not need drug discontinuation. Appropriate diagnosis and management of drug hypersensitivity reactions are essential, especially in patients with very low CD4+ T-cell count and multiple opportunistic infections. Clinicians should aware of different half-life of each drug when decided to stop the drug. Knowledge of the metabolism, recognition of the risk factors, and the ability to suggest the probability of particular drug as causative are also important points. A step wise rechallenge test or desensitization with the offending drug might be a preferable action and more commonly used in managing drug hypersensitivity in HIV-infected patients. Desensitization protocols have been successfully done for several antiretroviral and opportunistic infection drugs. PMID:24527412

Management of hypersensitivity to platinum- and taxane-based chemotherapy: cepo review and clinical recommendations

PubMed Central

Boulanger, J.; Boursiquot, J.N.; Cournoyer, G.; Lemieux, J.; Masse, M.S.; Almanric, K.; Guay, M.P.

2014-01-01

Background Although antineoplastic agents are critical in the treatment of cancer, they can potentially cause hypersensitivity reactions that can have serious consequences. When such a reaction occurs, clinicians can either continue the treatment, at the risk of causing a severe or a potentially fatal anaphylactic reaction, or stop the treatment, although it might be the only one available. The objective of the present work was to evaluate the effectiveness of methods used to prevent and treat hypersensitivity reactions to platinum- or taxane-based chemotherapy and to develop evidence-based recommendations. Methods The scientific literature published to December 2013, inclusive, was reviewed. Results Premedication with antihistamines, H2 blockers, and corticosteroids is not effective in preventing hypersensitivity reactions to platinum salts. However, premedication significantly reduces the incidence of hypersensitivity to taxanes. A skin test can generally be performed to screen for patients at risk of developing a severe reaction to platinum salts in the presence of grade 1 or 2 reactions, but skin testing does not appear to be useful for taxanes. A desensitization protocol allows for re-administration of either platinum- or taxane-based chemotherapy to some patients without causing severe hypersensitivity reactions. Conclusions Several strategies such as premedication, skin testing, and desensitization protocols are available to potentially allow for administration of platinum- or taxane-based chemotherapy to patients who have had a hypersensitivity reaction and for whom no other treatment options are available. Considering the available evidence, the Comité de l’évolution des pratiques en oncologie made recommendations for clinical practice in Quebec. PMID:25089112

Repeated exposure to methamphetamine induces sex-dependent hypersensitivity to ischemic injury in the adult rat heart

PubMed Central

Seeley, Sarah L.; Stoops, Thorne S.; D’Souza, Manoranjan S.

2017-01-01

Background We previously reported that adult female, but not male rats that were prenatally exposed to methamphetamine exhibit myocardial hypersensitivity to ischemic injury. However, it is unknown whether hypersensitivity to ischemic injury develops when rats are exposed to methamphetamine during adulthood. The goal of this study was to determine whether methamphetamine exposure during adulthood sensitizes the heart to ischemic injury. Methods Adult male and female rats received daily injections of methamphetamine (5 mg/kg) or saline for 10 days. Their hearts were isolated on day 11 and subjected to a 20 min ischemic insult on a Langendorff isolated heart apparatus. Cardiac contractile function was measured by an intraventricular balloon, and infarct size was measured by triphenyltetrazolium chloride staining. Results Hearts from methamphetamine-treated females exhibited significantly larger infarcts and suppressed postischemic recovery of contractile function compared to hearts from saline-treated females. In contrast, methamphetamine had no effect on infarct size or contractile recovery in male hearts. Subsequent experiments demonstrated that hypersensitivity to ischemic injury persisted in female hearts following a 1 month period of abstinence from methamphetamine. Myocardial protein kinase C-ε expression, Akt phosphorylation, and ERK phosphorylation were unaffected by adult exposure to methamphetamine. Conclusions Exposure of adult rats to methamphetamine sex-dependently increases the extent of myocardial injury following an ischemic insult. These data suggest that women who have a heart attack might be at risk of more extensive myocardial injury if they have a recent history of methamphetamine abuse. PMID:28575091

Repeated exposure to methamphetamine induces sex-dependent hypersensitivity to ischemic injury in the adult rat heart.

PubMed

Rorabaugh, Boyd R; Seeley, Sarah L; Stoops, Thorne S; D'Souza, Manoranjan S

2017-01-01

We previously reported that adult female, but not male rats that were prenatally exposed to methamphetamine exhibit myocardial hypersensitivity to ischemic injury. However, it is unknown whether hypersensitivity to ischemic injury develops when rats are exposed to methamphetamine during adulthood. The goal of this study was to determine whether methamphetamine exposure during adulthood sensitizes the heart to ischemic injury. Adult male and female rats received daily injections of methamphetamine (5 mg/kg) or saline for 10 days. Their hearts were isolated on day 11 and subjected to a 20 min ischemic insult on a Langendorff isolated heart apparatus. Cardiac contractile function was measured by an intraventricular balloon, and infarct size was measured by triphenyltetrazolium chloride staining. Hearts from methamphetamine-treated females exhibited significantly larger infarcts and suppressed postischemic recovery of contractile function compared to hearts from saline-treated females. In contrast, methamphetamine had no effect on infarct size or contractile recovery in male hearts. Subsequent experiments demonstrated that hypersensitivity to ischemic injury persisted in female hearts following a 1 month period of abstinence from methamphetamine. Myocardial protein kinase C-ε expression, Akt phosphorylation, and ERK phosphorylation were unaffected by adult exposure to methamphetamine. Exposure of adult rats to methamphetamine sex-dependently increases the extent of myocardial injury following an ischemic insult. These data suggest that women who have a heart attack might be at risk of more extensive myocardial injury if they have a recent history of methamphetamine abuse.

Low incidence of anti-drug antibodies in patients with type 2 diabetes treated with once-weekly glucagon-like peptide-1 receptor agonist dulaglutide.

PubMed

Milicevic, Z; Anglin, G; Harper, K; Konrad, R J; Skrivanek, Z; Glaesner, W; Karanikas, C A; Mace, K

2016-05-01

Therapeutic administration of peptides may result in anti-drug antibody (ADA) formation, hypersensitivity adverse events (AEs) and reduced efficacy. As a large peptide, the immunogenicity of once-weekly glucagon-like peptide-1 (GLP-1) receptor agonist dulaglutide is of considerable interest. The present study assessed the incidence of treatment-emergent dulaglutide ADAs, hypersensitivity AEs, injection site reactions (ISRs), and glycaemic control in ADA-positive patients in nine phase II and phase III trials (dulaglutide, N = 4006; exenatide, N = 276; non-GLP-1 comparators, N = 1141). Treatment-emergent dulaglutide ADAs were detected using a solid-phase extraction acid dissociation binding assay. Neutralizing ADAs were detected using a cell-based assay derived from human endothelial kidney cells (HEK293). A total of 64 dulaglutide-treated patients (1.6% of the population) tested ADA-positive versus eight (0.7%) from the non-GLP-1 comparator group. Of these 64 patients, 34 (0.9%) had dulaglutide-neutralizing ADAs, 36 (0.9%) had native-sequence GLP-1 (nsGLP-1) cross-reactive ADAs and four (0.1%) had nsGLP-1 neutralization ADAs. The incidence of hypersensitivity AEs and ISRs was similar in the dulaglutide versus placebo groups. No dulaglutide ADA-positive patient reported hypersensitivity AEs. Because of the low incidence of ADAs, it was not possible to establish their effect on glycaemic control. © 2016 John Wiley & Sons Ltd.

Occlusal loading and cross-linking effects on dentin collagen degradation in physiological conditions.

PubMed

Turco, Gianluca; Frassetto, Andrea; Fontanive, Luca; Mazzoni, Annalisa; Cadenaro, Milena; Di Lenarda, Roberto; Tay, Franklin R; Pashley, David H; Breschi, Lorenzo

2016-02-01

This study evaluated the ability of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC) to improve the stability of demineralized dentin collagen matrices when subjected to mechanical cycling by means of Chewing Simulation (CS). Demineralized dentin disks were randomly assigned to four groups (N=4): (1) immersion in artificial saliva at 37°C for 30 days; (2) pre-treatment with 0.5 M EDC for 60 s, then stored as in Group 1; (3) CS challenge (50 N occlusal load, 30 s occlusal time plus 30 s with no load, for 30 days); (4) pre-treatment with 0.5 M EDC as in Group 2 and CS challenge as in Group 3. Collagen degradation was evaluated by sampling storage media for ICTP and CTX telopeptides. EDC treated specimens showed no significant telopeptides release, irrespective of the aging method. Cyclic stressing of EDC-untreated specimens caused significantly higher ICTP release at day 1, compared to static storage, while by days 3 and 4, the ICTP release in the cyclic group fell significantly below the static group, and then remained undetectable from 5 to 30 days. CTX release in the cyclic groups, on EDC-untreated control specimens was always lower than in the static group in days 1-4, and then fell to undetectable for 30 days. This study showed that chewing stresses applied to control untreated demineralized dentin increased degradation of collagen in terms of CTX release, while collagen crosslinking agents may prevent dentin collagen degradation, irrespective of simulated occlusal function. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Reinforcement of dentin in self-etch adhesive technology: a new concept.

PubMed

Waidyasekera, Kanchana; Nikaido, Toru; Weerasinghe, Dinesh S; Ichinose, Shizuko; Tagami, Junji

2009-08-01

Characterize the ultramorphology and secondary caries inhibition potential of different dentin adhesive systems in order to find a satisfactory explanation resist to recurrent caries. Human premolar dentin was treated with one of the two self-etching adhesive systems, Clearfil SE Bond, Clearfil Protect Bond or an acid-etching adhesive system, Single Bond. The bonded interface was exposed to an artificial demineralizing solution (pH 4.5) for 90 min and then 5% sodium hypochlorite for 20 min. Transmission electron microscopic observation was performed at the adhesive-dentin interface. The width of the reinforced zone was measured and data were analyzed with univariate analysis of variance under general linear model. In order to identify type of crystallites in the reinforced zone selected area electron diffraction was performed. An acid-base resistant zone (ABRZ) was found adjacent to the hybrid layer in the outer lesion front with only Clearfil SE Bond and Clearfil Protect Bond, while Single Bond was devoid of this protective zone. Crystallite arrangement and the ultramorphology were almost similar in the corresponding regions of Clearfil SE Bond and Clearfil Protect Bond. However, thickness of the ABRZ at the mid portion was 1159(+/-41.91)nm in Clearfil protect Bond, which was significantly thicker than that of Clearfil SE Bond (F=514.84, p<0.001). Selected area electron diffraction confirmed the crystallites in the zone as apatite. The self-etching adhesive systems created a new reinforced acid resistant dentin under the hybrid layer. Difference in the thickness of the zone expressed a different potential for demineralization inhibition.

Anatomical analysis of the resected roots of mandibular first molars after failed non-surgical retreatment

PubMed Central

2018-01-01

Objectives Understanding the reason for an unsuccessful non-surgical endodontic treatment outcome, as well as the complex anatomy of the root canal system, is very important. This study examined the cross-sectional root canal structure of mandibular first molars confirmed to have failed non-surgical root canal treatment using digital images obtained during intentional replantation surgery, as well as the causative factors of the failed conventional endodontic treatments. Materials and Methods This study evaluated 115 mandibular first molars. Digital photographic images of the resected surface were taken at the apical 3 mm level and examined. The discolored dentin area around the root canal was investigated by measuring the total surface area, the treated areas as determined by the endodontic filling material, and the discolored dentin area. Results Forty 2-rooted teeth showed discolored root dentin in both the mesial and distal roots. Compared to the original filled area, significant expansion of root dentin discoloration was observed. Moreover, the mesial roots were significantly more discolored than the distal roots. Of the 115 molars, 92 had 2 roots. Among the mesial roots of the 2-rooted teeth, 95.7% of the roots had 2 canals and 79.4% had partial/complete isthmuses and/or accessory canals. Conclusions Dentin discoloration that was not visible on periapical radiographs and cone-beam computed tomography was frequently found in mandibular first molars that failed endodontic treatment. The complex anatomy of the mesial roots of the mandibular first molars is another reason for the failure of conventional endodontic treatment. PMID:29765897

Effects of ethylenediaminetetraacetic, etidronic and peracetic acid irrigation on human root dentine and the smear layer.

PubMed

Lottanti, S; Gautschi, H; Sener, B; Zehnder, M

2009-04-01

To evaluate the effects of ethylenediaminetetraacetic (EDTA), etidronic (EA) and peracetic acid (PA) when used in conjunction with sodium hypochlorite (NaOCl) as root canal irrigants on calcium eluted from canals, smear layer, and root dentine demineralization after instrumentation/irrigation. Single-rooted human premolars were irrigated as follows (n = 12 per group): (1) 1% NaOCl during instrumentation, deionized water after instrumentation, (2) 1% NaOCl during, 17% EDTA after instrumentation, (3) a 1 : 1-mixture of 2% NaOCl and 18% EA during and after instrumentation, and (4) 1% NaOCl during, 2.25% PA after instrumentation. Irrigant volumes and contact times were 10 mL/15 min during and 5 mL/3 min after instrumentation. The evaluated outcomes were eluted calcium by atomic absorption spectroscopy, smear-covered areas by scanning electron microscopy in secondary electron mode and apparent canal wall decalcifications on root transsections in backscatter mode. For the smear layer analysis, sclerotic dentine was taken into consideration. Results were compared using appropriate parametric and nonparametric tests, alpha = 0.05. The statistical comparison of the protocols regarding calcium elution revealed that protocol (1) yielded less calcium than (3), which yielded less than protocols (2) and (4). Most of the instrumented canal walls treated with one of the decalcifying agents were free of smear layer. Protocols (1) and (3) caused no decalcification of root dentine, whilst (2) and (4) showed substance typical demineralization patterns. The decalcifying agents under investigation were all able to remove or prevent a smear layer. However, they eroded the dentine wall differently.

Phase, compositional, and morphological changes of human dentin after Nd:YAG laser treatment.

PubMed

Lin, C P; Lee, B S; Lin, F H; Kok, S H; Lan, W H

2001-06-01

Although techniques for repairing root fracture have been proposed, the prognosis is generally poor. If the fusion of a root fracture by laser is possible, it will offer an alternative to extraction. Our group has attempted to use lasers to fuse a low melting-point bioactive glass to fractured dentin. This report is focused on the phase, compositional, and morphological changes observed by means of X-ray diffractometer, Fourier transforming infrared spectroscopy, and scanning electron microscopy-energy dispersive X-ray spectroscopy in human dentin after exposure to Nd:YAG laser. The irradiation energies were from 150 mJ/ pulse-10 pps-4 s to 150 mJ/pulse-30 pps-4 s. After exposure to Nd:YAG laser, dentin showed four peaks on the X-ray diffractometer that corresponding to a-tricalcium phosphate (TCP) and beta-TCP at 20 = 30.78 degrees/34.21 degrees and 32.47 degrees/33.05 degrees, respectively. The peaks of a-TCP and beta-TCP gradually increased in intensity with the elevation of irradiation energy. In Fourier transforming infrared analysis, two absorption bands at 2200 cm(-1) and 2015 cm(-1) could be traced on dentin treated by Nd:YAG laser with the irradiation energies beyond 150 mJ/pulse-10 pps-4 s. The energy dispersive X-ray results showed that the calcium/phosphorus ratios of the irradiated area proportionally increased with the elevation of irradiation energy. The laser energies of 150 mJ/ pulse-30 pps-4 s and 150 mJ/pulse-20 pps-4 s could result in the a-TCP formation and collagen breakdown. However, the formation of glass-like melted substances without a-TCP at the irradiated site was induced by the energy output of 150 mJ/ pulse-10 pps-4 s. Scanning electron micrographs also revealed that the laser energy of 150 mJ/ pulse-10 pps-4 s was sufficient to prompt melting and recrystallization of dentin crystals without cracking. Therefore, we suggest that the irradiation energy of Nd:YAG laser used to fuse a low melting-point bioactive glass to dentin is 150 mJ/ pulse-10 pps-4 s.

DENTINE CARIES: ACID-TOLERANT MICROORGANISMS AND ASPECTS ON COLLAGEN DEGRADATION.

PubMed

Lager, Anders Hedenbjörk

2014-01-01

Dental caries is a common disease all over the world, despite the fact that it can be both effectively prevented and treated. It is driven by acids produced by oral microorganisms as a consequence of their metabolism of dietary carbohydrates. Given enough acid challenge, eventually the tooth enamel barrier will be broken down, and the carious lesion will extend into underlying hard tissue, forming a macroscopic cavity in the dentine. In comparison to biofilm on enamel, a dentine carious lesion provides a vastly different environment for the residing microorganisms. The environment influences the types and numbers of microorganisms that can colonize the dentine caries lesion. The overall aims for this thesis are to enumerate and further study microorganisms found in established dentine caries lesions and also to illuminate how host-derived proteolytic enzymes might contribute to this degradation, not only to better understand the caries process in dentine but also to find incitements for new methods to influence the natural progression of caries lesions. In Paper I, the numbers of remaining viable microorganisms after completed excavation using two excavation methods were investigated. Samples of carious dentine tissue were collected before and after excavation and cultivated on different agar media in different atmospheres. Analysis was performed by counting the number of colony-forming units (CFUs). Key findings: The number of remaining microorganisms after excavation was low for both methods, but some microorganisms always remained in the cavity floors even when the cavities were judged as caries free using normal clinical criteria. In Paper II, the acid tolerant microbiota in established dentine caries lesions was investigated. Samples were taken as in Paper I, but on three levels (superficial, center of lesion, floor of lesion after completed excavation). The samples were cultivated in anaerobic conditions on solid pH-selective agar media of different acidity. Key findings: Each investigated lesion harbored a unique microbiota in terms of both species composition and numbers of microorganisms. This indicates that various combinations of aciduric microorganisms can colonize, survive in and probably also propagate dentine carious lesions. We also found that solid pH-selective agars can be used successfully to select acid-tolerant microorganisms in caries lesions. This would preserve their phenotypic traits for further study. In Paper III, the relation between salivary levels of matrix metalloproteinase-8 (MMP-8), salivary levels of tissue inhibitor of MMP (TIMP-1), and the presence of manifest caries lesions in a large number of subjects was investigated. Saliva samples were collected and analyzed for concentrations of MMP-8, TIMP-1 and total protein using immunofluorometric assays, enzyme linked immunosorbent assays and Bradford assays, respectively. Key findings: Subjects with manifest caries lesions had significantly elevated levels of salivary MMP-8 compared to subjects without caries lesions. TIMP-1 was not significant in any case. In Paper IV, a new method for generating bioactive demineralized dentine matrix substrate (DDM) was developed using a dialysis system and two different demineralization approaches (acetic acid or EDTA). The generated DDM was subsequently analyzed for the presence of type 1 collagen, active MMP-8 and hydroxyproline (HYP) levels using SDS-PAGE, ELISA or immunofluorescence assay. Key findings: Both demineralization methods produced a substrate rich in collagen and with preserved MMP-8 activity. This report presents new knowledge on the composition of the acid tolerant dentine caries microbiota from three levels in dentine carious lesions and on the efficacy of operative caries removal on the numbers of viable microorganisms in the caries free cavity using two operative methods. Moreover, the basic mechanisms behind collagen degradation in the dentine caries process are studied from both a clinical and laboratory perspective. The report also provides a reference for further studies on dentine caries microbiology and dentine caries collagen degradation mechanisms, both of which are known only in part.

Clinical study of Mineral Trioxide Aggregate in primary molars. Comparison between Grey and White MTA--a long term follow-up (84 months).

PubMed

Cardoso-Silva, Cristina; Barbería, Elena; Maroto, Myriam; García-Godoy, Franklin

2011-02-01

The aim of the present study was to conduct a clinical and radiographic long-term evaluation of pulpotomy in temporary molars performed with Grey and White Mineral Trioxide Aggregate (MTA) and compare the results of Grey and White MTA pulpotomies in a sample of 233 primary molars with a maximum follow-up period of 84 months. The sample was selected from patients treated at the Department of Pediatric Dentistry, Faculty of Dentistry, Complutense University of Madrid, Spain. This prospective study included first and second primary molars treated with pulpotomy with Grey or White MTA, controlled for a maximum follow-up period of 84 months. Statistical analysis of clinical and radiographic findings was completed using ANOVA (P<0.05). Follow-up evaluations, performed every 6 months, revealed that only 2 molars treated with White MTA presented abscess and pathological mobility. Radiographic examination of the 210 molars revealed unfavourable pulp response in only 6 molars (internal or furcation root resorption), without statistically significant differences between Grey and White MTA. Two radiological findings were noticed: dentine bridge formation and partial or total root canal stenosis. Grey MTA induced a higher percentage of dentine bridges with statistically significant differences (P<0.05), and a higher percentage of pulp canal stenosis, without a statistically significant difference. Grey and White MTA presented high levels of clinical and radiographic success. Although the present study showed evidence of a very good biologic response with both types of MTA, Grey MTA showed significantly higher number of dentine bridge formation than White MTA. Copyright © 2010 Elsevier Ltd. All rights reserved.

Safety of nonthermal atmospheric pressure plasma for tooth bleaching evaluated in terms of microhardness and mineral content

NASA Astrophysics Data System (ADS)

Nam, S. H.; Hong, J. W.; Lee, H. J.; Jeon, Y. C.; Kim, G. C.

2017-08-01

The purpose of this study was to evaluate the influence of bleaching with nonthermal atmospheric pressure plasma and 15% hydrogen peroxide (HP) or 15% carbamide peroxide (CP). Sixty human enamel and dentin slabs were randomly assigned to six groups as follows: Group 1 was a control group and did not receive any treatment; Group 2 was exposed only to plasma, as a negative control; Group 3 was treated with 15% HP; Group 4 was treated with 15% HP plus plasma; Group 5 was treated with 15% CP alone; and Group 6 was treated with 15% CP plus plasma during 30 min bleaching treatments. A microhardness measurement was conducted according to a microhardness tester. The amount of calcium (Ca), phosphorus (P), chloride (Cl), sodium (Na), magnesium (Mg), and zinc (Zn) in the enamel and dentin was quantified with an electron probe microanalyzer (EPMA). The data were analyzed by using the Student’s t test and one-way analysis of variance (ANOVA), complemented by Tukey’s test. The statistical analysis did not show any significant differences in microhardness values and six mineral contents in all groups (p  >  0.05). Therefore, we believe that the application of nonthermal atmospheric pressure plasma is a safe energy source for tooth bleaching.

Risk Factors for Oxaliplatin-Induced Hypersensitivity Reactions in Japanese Patients with Advanced Colorectal Cancer

PubMed Central

Seki, Kyoko; Senzaki, Kenzou; Tsuduki, Yasuo; Ioroi, Takeshi; Fujii, Michiko; Yamauchi, Hiroko; Shiraishi, Yukinari; Nakata, Izumi; Nishiguchi, Kohshi; Matsubayashi, Teruhisa; Takakubo, Yoshihide; Okamura, Noboru; Yamamori, Motohiro; Tamura, Takao; Sakaeda, Toshiyuki

2011-01-01

Objective: Previously, we suggested that oxaliplatin (L-OHP)-related grade 3/4 hypersensitivity reactions occurred immediately after the initiation, but grade 1/2 reactions did not. This study was conducted to clarify the risk factors for L-OHP-related hypersensitivity reactions. Methods: Clinical data from 108 Japanese patients with colorectal cancer were analyzed, who were treated with L-OHP-containing regimens, FOLFOX4 and/or mFOLFOX6. The risk factors examined included demographic data, preexisting allergies, laboratory test data, treatment regimen, treatment line of therapy, pretreatment with steroids, total number of cycles and cumulative amount of L-OHP. Results: The incidence of grade 1/2 and grade 3/4 hypersensitivity reactions were found at 13.0% (14/108) and 9.3% (10/108), respectively. Female (P=0.037), preexisting allergies (P=0.004) and lower level of lactate dehydrogenase (P=0.003) were risk factors for grade 1/2 hypersensitivity reactions, and higher neutrophil count (P=0.043) and lower monocyte count (P=0.007) were for grade 3/4 reactions. Total number of cycles were larger in the patients with grade 3/4 reactions than those without reactions (P=0.049). Conclusions: Further extensive examination with a large number of patients is needed to establish a patient management strategy. PMID:21448307

Subgroups of Paediatric Acute Lymphoblastic Leukaemia Might Differ Significantly in Genetic Predisposition to Asparaginase Hypersensitivity

PubMed Central

Kutszegi, Nóra; Semsei, Ágnes F.; Gézsi, András; Sági, Judit C.; Nagy, Viktória; Csordás, Katalin; Jakab, Zsuzsanna; Lautner-Csorba, Orsolya; Gábor, Krisztina Míta; Kovács, Gábor T.; Erdélyi, Dániel J.; Szalai, Csaba

2015-01-01

L-asparaginase (ASP) is a key element in the treatment of paediatric acute lymphoblastic leukaemia (ALL). However, hypersensitivity reactions (HSRs) to ASP are major challenges in paediatric patients. Our aim was to investigate genetic variants that may influence the risk to Escherichia coli-derived ASP hypersensitivity. Sample and clinical data collection was carried out from 576 paediatric ALL patients who were treated according to protocols from the Berlin—Frankfurt—Münster Study Group. A total of 20 single nucleotide polymorphisms (SNPs) in GRIA1 and GALNT10 genes were genotyped. Patients with GRIA1 rs4958351 AA/AG genotype showed significantly reduced risk to ASP hypersensitivity compared to patients with GG genotype in the T-cell ALL subgroup (OR = 0.05 (0.01–0.26); p = 4.70E-04), while no such association was found in pre-B-cell ALL. In the medium risk group two SNPs of GRIA1 (rs2055083 and rs707176) were associated significantly with the occurrence of ASP hypersensitivity (OR = 0.21 (0.09–0.53); p = 8.48E-04 and OR = 3.02 (1.36–6.73); p = 6.76E-03, respectively). Evaluating the genders separately, however, the association of rs707176 with ASP HSRs was confined only to females. Our results suggest that genetic variants of GRIA1 might influence the risk to ASP hypersensitivity, but subgroups of patients can differ significantly in this respect. PMID:26457809

Effects of water storage on bond strength and dentin sealing ability promoted by adhesive systems.

PubMed

Cantanhede de Sá, Renata Bacelar; Oliveira Carvalho, Adriana; Puppin-Rontani, Regina Maria; Ambrosano, Glaúcia Maria; Nikaido, Toru; Tagami, Junji; Giannini, Marcelo

2012-12-01

To evaluate the dentin bond strength (BS) and sealing ability (SA) promoted by adhesive systems after 24 h or 6 months of water storage. The tested adhesive systems were: one three-step etch-and-rinse adhesive (Adper Scotchbond Multi-Purpose, SBMP) and three single-step self-etching systems (Adper Easy Bond, Bond Force, and G-Bond Plus). Bovine incisors were used for both evaluations, BS (n = 11) and SA (n = 5). To examine BS, the buccal surface was ground with SiC paper to expose a flat dentin surface. After adhesive application, a block of resin composite was incrementally built up over the bonded surface and sectioned into sticks. These bonded specimens were subjected to microtensile bond strength testing after 24 h and 6 months of water storage using a universal testing machine. For SA analysis, enamel was removed from the buccal surfaces. The teeth were connected to a device to measure the initial SA (10 psi), and the second measurement was taken after treating dentin with EDTA. Afterwards, the adhesive systems were applied to dentin and the SA was re-measured for each adhesive after 24 h and 6 months of water storage. The SA was expressed in terms of percentage of dentinal sealing. BS and SA data were submitted to two-way ANOVA and Tukey's test (α = 0.05). All adhesives showed a reduction of SA after 6 months of water storage. The SA promoted by self-etching adhesives was higher than that of SBMP. No adhesive system showed a reduction of the BS after 6 months. Sealing ability was affected by water storage, while no changes in microtensile bond strength were observed after 6 months of water storage. The single-step self-etching systems showed greater sealing ability than did SBMP, even after 6 months of storage in water.

Etidronate from Medicine to Endodontics: effects of different irrigation regimes on root dentin roughness

PubMed Central

TARTARI, Talita; DUARTE JUNIOR, Anivaldo Pereira; SILVA JÚNIOR, José Otávio Carrera; KLAUTAU, Eliza Burlamaqui; SILVA E SOUZA JUNIOR, Mario Honorato; SILVA E SOUZA, Patrícia de Almeida Rodrigues

2013-01-01

An increase in dentin roughness, associated with surface composition, contributes to bacterial adherence in recontaminations. Surface roughness is also important for micromechanical interlocking of dental materials to dentin, and understanding the characteristics of the surface is essential to obtain the adhesion of root canal sealers that have different physico-chemical characteristics. Objectives To evaluate the effects of sodium hypochlorite (NaOCl), ethylenediaminetetraacetic (EDTA), etidronic (HEBP), and citric acid (CA) associated with different irrigation regimens on root dentin roughness. Material and Methods Forty-five root halves of anterior teeth were used. The root parts were sectioned in thirds, embedded in acrylic resin and polished to a standard surface roughness. Initially, the samples of each third were randomly assigned into 3 groups and treated as follows: G1 - saline solution (control); G2 - 5% NaOCl+18% HEBP mixed in equal parts; and G3 - 2.5% NaOCl. After initial measuments, the G3 samples were distributed into subgroups G4, G5 and G6, which were subjected to 17% EDTA, 10% CA and 9% HEBP, respectively. Following the new measuments, these groups received a final flush with 2.5% NaOCl, producing G7, G8 and G9. The dentin surface roughness (Ra) was determined before and after treatments using a profilometer. The Wilcoxon test (α<0.05) was used to compare the values before and after treatments, and the Friedman test (α<0.05) to detect any differences among root thirds. Results (i) NaOCl did not affect the surface roughness; (ii) there was a significant increase in roughness after the use of chelating agents (P<0.01); and (iii) only the G3 group showed a difference in surface roughness between apical third and other thirds of the teeth (P<0.0043). Conclusion Only the irrigation regimens that used chelating agents altered the roughness of root dentin. PMID:24212986

Etidronate from medicine to endodontics: effects of different irrigation regimes on root dentin roughness.

PubMed

Tartari, Talita; Duarte Junior, Anivaldo Pereira; Silva Júnior, José Otávio Carrera; Klautau, Eliza Burlamaqui; Silva E Souza Junior, Mario Honorato; Silva E Souza Junior, Patrícia de Almeida Rodrigues

2013-01-01

An increase in dentin roughness, associated with surface composition, contributes to bacterial adherence in recontaminations. Surface roughness is also important for micromechanical interlocking of dental materials to dentin, and understanding the characteristics of the surface is essential to obtain the adhesion of root canal sealers that have different physico-chemical characteristics. To evaluate the effects of sodium hypochlorite (NaOCl), ethylenediaminetetraacetic (EDTA), etidronic (HEBP), and citric acid (CA) associated with different irrigation regimens on root dentin roughness. Forty-five root halves of anterior teeth were used. The root parts were sectioned in thirds, embedded in acrylic resin and polished to a standard surface roughness. Initially, the samples of each third were randomly assigned into 3 groups and treated as follows: G1 - saline solution (control); G2 - 5% NaOCl+18% HEBP mixed in equal parts; and G3 - 2.5% NaOCl. After initial measuments, the G3 samples were distributed into subgroups G4, G5 and G6, which were subjected to 17% EDTA, 10% CA and 9% HEBP, respectively. Following the new measuments, these groups received a final flush with 2.5% NaOCl, producing G7, G8 and G9. The dentin surface roughness (Ra) was determined before and after treatments using a profilometer. The Wilcoxon test (α<0.05) was used to compare the values before and after treatments, and the Friedman test (α<0.05) to detect any differences among root thirds. (i) NaOCl did not affect the surface roughness; (ii) there was a significant increase in roughness after the use of chelating agents (P<0.01); and (iii) only the G3 group showed a difference in surface roughness between apical third and other thirds of the teeth (P<0.0043). Only the irrigation regimens that used chelating agents altered the roughness of root dentin.

Effect of cavity disinfectants on antibacterial activity and microtensile bond strength in class I cavity.

PubMed

Kim, Bo-Ram; Oh, Man-Hwan; Shin, Dong-Hoon

2017-05-31

This study was performed to compare the antibacterial activities of three cavity disinfectants [chlorhexidine (CHX), NaOCl, urushiol] and to evaluate their effect on the microtensile bond strength of Scotchbond Universal Adhesive (3M-ESPE, St. Paul, MN, USA) in class I cavities. In both experiments, class I cavities were prepared in dentin. After inoculation with Streptococcus mutans, the cavities of control group were rinsed and those of CHX, NaOCl and urushiol groups were treated with each disinfectant. Standardized amounts of dentin chips were collected and number of S. mutans was determined. Following the same cavity treatment, same adhesive was applied in etch-and-rinse mode. Then, microtensile bond strength was evaluated. The number of S. mutans was significantly reduced in the cavities treated with CHX, NaOCl, and urushiol compared with control group (p<0.05). However, there was a significant bond strength reduction in NaOCl group, which showed statistical difference compared to the other groups (p<0.05).

Condition-specific role of colonic inflammatory molecules in persistent functional colorectal hypersensitivity in the mouse

PubMed Central

La, Jun-Ho; Gebhart, G. F.

2014-01-01

Background A low-level inflammation has been hypothesized to mediate visceral hypersensitivity in functional bowel disorders that persist after or even in the absence of gut inflammation. We aimed to test the efficacy of a steroidal anti-inflammatory treatment, and identify local inflammatory molecules mediating post- and non-inflammatory colorectal hypersensitivity using two mouse models. Methods Visceromotor responses to colorectal distension were quantified as a measure of colorectal sensitivity. On day 1, mice received intracolonic saline (control), trinitrobenzenesulfonic acid (post-inflammatory on day 15), or acidified hypertonic saline (non-inflammatory). Colorectal sensitivity before (day 10) and after (day 15) four-day dexamethasone treatment was compared, and colonic gene expression of inflammatory molecules was quantified. Results Dexamethasone effectively inhibited gene expression of inflammatory molecules such as interleukin (IL)-1β and mast cell protease-1 in the colon, but did not attenuate colorectal hypersensitivity in either model. Gene expression of inflammatory molecules in the colon did not differ between control and the non-inflammatory model, but the post-inflammatory model showed increased IL-10 and tight junction protein 2, and decreased IL-6, transforming growth factor (TGF)-β, a precursor of β-endorphin, occludin, and mucin 2. While no common molecule explained colorectal hypersensitivity in these models, hypersensitivity was positively correlated with TGF-β2 mRNA in control, and with IL-1β, inhibin βA and prostaglandin E2 synthase in the dexamethasone-treated post-inflammatory model. In the non-inflammatory model, cyclooxygenase-2 mRNA was negatively correlated with colorectal sensitivity. Conclusion These results suggest that persistent functional colorectal hypersensitivity is mediated by condition-specific mediators whose gene expression in the colon is not inevitably sensitive to steroidal anti-inflammatory treatment. PMID:25307695

Identification of spinal circuits involved in touch-evoked dynamic mechanical pain

PubMed Central

Cheng, Longzhen; Duan, Bo; Huang, Tianwen; Zhang, Yan; Chen, Yangyang; Britz, Olivier; Garcia-Campmany, Lidia; Ren, Xiangyu; Vong, Linh; Lowell, Bradford B.; Goulding, Martyn; Wang, Yun; Ma, Qiufu

2017-01-01

Mechanical hypersensitivity is a debilitating symptom associated with millions of chronic pain patients. It exists in distinct forms, including brush-evoked dynamic and filament-evoked punctate. Here we report that dynamic mechanical hypersensitivity induced by nerve injury or inflammation was compromised in mice with ablation of spinal VT3Lbx1 neurons defined by coexpression of VGLUT3Cre and Lbx1Flpo, as indicated by the loss of brush-evoked nocifensive responses and conditional place aversion. Electrophysiological recordings show that VT3Lbx1 neurons form morphine-resistant polysynaptic pathways relaying inputs from low-threshold Aβ mechanoreceptors to lamina I output neurons. Meanwhile, the subset of somatostatin (SOM) lineage neurons preserved in VT3Lbx1 neuron-ablated mice is largely sufficient to mediate von Frey filament-evoked punctate mechanical hypersensitivity, including both morphine-sensitive and morphine-resistant forms. Furthermore, acute silencing of VT3Lbx1 neurons attenuated pre-established dynamic mechanical hypersensitivity induced by nerve injury, suggesting these neurons as a potential cellular target for treating this form of neuropathic pain. PMID:28436981

Cough Hypersensitivity Syndrome: A Few More Steps Forward

PubMed Central

Song, Woo-Jung

2017-01-01

Cough reflex is a vital protective mechanism against aspiration, but when dysregulated, it can become hypersensitive. In fact, chronic cough is a significant medical problem with a high degree of morbidity. Recently, a unifying paradigm of cough hypersensitivity syndrome has been proposed. It represents a clinical entity in which chronic cough is a major presenting problem, regardless of the underlying condition. Although it remains a theoretical construct, emerging evidence suggests that aberrant neurophysiology is the common etiology of this syndrome. Recent success in randomized clinical trials using a P2X3 receptor antagonist is the first major advance in the therapeutics of cough in the past 30 years; it at last provides a strategy for treating intractable cough as well as an invaluable tool for dissecting the mechanism underpinning cough hypersensitivity. Additionally, several cough measurement tools have been validated for use and will help assess the clinical relevance of cough in various underlying conditions. Along with this paradigm shift, our understanding of cough mechanisms has improved during the past decades, allowing us to continue to take more steps forward in the future. PMID:28677352

Cochlear hearing loss in patients with Laron syndrome.

PubMed

Attias, Joseph; Zarchi, Omer; Nageris, Ben I; Laron, Zvi

2012-02-01

The aim of this prospective clinical study was to test auditory function in patients with Laron syndrome, either untreated or treated with insulin-like growth factor I (IGF-I). The study group consisted of 11 patients with Laron syndrome: 5 untreated adults, 5 children and young adults treated with replacement IGF-I starting at bone age <2 years, and 1 adolescent who started replacement therapy at bone age 4.6 years. The auditory evaluation included pure tone and speech audiometry, tympanometry and acoustic reflexes, otoacoustic emissions, loudness dynamics, auditory brain stem responses and a hyperacusis questionnaire. All untreated patients and the patient who started treatment late had various degrees of sensorineural hearing loss and auditory hypersensitivity; acoustic middle ear reflexes were absent in most of them. All treated children had normal hearing and no auditory hypersensitivity; most had recordable middle ear acoustic reflexes. In conclusion, auditory defects seem to be associated with Laron syndrome and may be prevented by starting treatment with IGF-I at an early developmental age.

Incidence of immediate hypersensitivity reaction and serum sickness following administration of Crotalidae polyvalent immune Fab antivenom: a meta-analysis.

PubMed

Schaeffer, Tammi H; Khatri, Vaishali; Reifler, Liza M; Lavonas, Eric J

2012-02-01

  Crotalidae polyvalent immune Fab (ovine) (FabAV) is commonly used in the treatment of symptomatic North American crotaline snake envenomation. When approved by the U.S. Food and Drug Administration in 2000, the incidences of immediate hypersensitivity reactions and serum sickness were reported as 0.14 and 0.18, respectively. The objective of this meta-analysis was to evaluate the incidence of immediate hypersensitivity reactions and serum sickness reported in studies of patients treated with FabAV therapy after North American crotaline envenomation.   The authors searched PubMed, Ovid MEDLINE, and EMBASE from January 1, 1997, to September 20, 2010, for English-language medical literature and cross-referenced bibliographies of reviewed articles. The published abstracts of the major toxicology conferences were also searched. All prospective and retrospective cohort studies with patients receiving FabAV therapy for North American crotaline envenomations were eligible for data abstraction. Two content experts reviewed full-text articles and extracted relevant study design and outcome data. Proportions of immediate hypersensitivity and serum sickness for each study were analyzed in a random-effects model to produce an overall estimate of immediate hypersensitivity and serum sickness incidence associated with FabAV administration.   The literature search revealed 11 unique studies of patients who received FabAV that contained information on immediate hypersensitivity reactions and serum sickness. The meta-analysis produced a combined estimate of the incidence of immediate hypersensitivity of 0.08 (95% confidence interval [CI] = 0.05 to 0.11) and a combined estimate of the incidence of serum sickness of 0.13 (95% CI = 0.07 to 0.21).   In this systematic literature review and meta-analysis, the combined estimates of the incidence of immediate hypersensitivity reactions and serum sickness from FabAV in the treatment of symptomatic North American crotaline envenomations appear to be lower than previously reported, at 0.08 and 0.13, respectively. © 2012 by the Society for Academic Emergency Medicine.

Enamel Matrix Derivative Promote Primary Human Pulp Cell Differentiation and Mineralization

PubMed Central

Riksen, Elisabeth Aurstad; Landin, Maria A.; Reppe, Sjur; Nakamura, Yukio; Lyngstadaas, Ståle Petter; Reseland, Janne E.

2014-01-01

Enamel matrix derivative (EMD) has been found to induce reactive dentin formation; however the molecular mechanisms involved are unclear. The effect of EMD (5–50 μg/mL) on primary human pulp cells were compared to untreated cells and cells incubated with 10−8 M dexamethasone (DEX) for 1, 2, 3, 7, and 14 days in culture. Expression analysis using Affymetrix microchips demonstrated that 10 μg/mL EMD regulated several hundred genes and stimulated the gene expression of proteins involved in mesenchymal proliferation and differentiation. Both EMD and DEX enhanced the expression of amelogenin (amel), and the dentinogenic markers dentin sialophosphoprotein (DSSP) and dentin matrix acidic phosphoprotein 1 (DMP1), as well as the osteogenic markers osteocalcin (OC, BGLAP) and collagen type 1 (COL1A1). Whereas, only EMD had effect on alkaline phosphatase (ALP) mRNA expression, the stimulatory effect were verified by enhanced secretion of OC and COL1A from EMD treated cells, and increased ALP activity in cell culture medium after EMD treatment. Increased levels of interleukin-6 (IL-6), interleukin-8 (IL-8), and monocyte chemoattractant proteins (MCP-1) in the cell culture medium were also found. Consequently, the suggested effect of EMD is to promote differentiation of pulp cells and increases the potential for pulpal mineralization to favor reactive dentine formation. PMID:24857913

Microleakage of light-cured resin and resin-modified glass-ionomer dentin bonding agents applied with co-cure vs pre-cure technique.

PubMed

Tulunoglu, O; Uçtaşh, M; Alaçam, A; Omürlü, H

2000-01-01

This in vitro study evaluated the effect of dentin bonding agents in reducing microleakage after three months in Class V restorations restored with Z100 resin composite. Materials tested were three types of resin-based dentin bonding agents: a multi-step (Scotchbond Multi-Purpose); a one-step (Scotchbond One-Step); a self-etching, self-priming (Clearfil Liner Bond) and a resin-modified glass ionomer (GC Fuji Bond LC). Class V cavity preparations with occlusal margins in enamel and gingival margins in cementum were prepared both on labial and lingual surfaces of extracted premolar teeth. Restorations (two per tooth) were distributed randomly into nine test groups (n = 10) consisting of the various DBAs applied with co-cure and pre-cure techniques, and no dentin bonding as a negative control group. Samples were stored in saline for three months, thermocycled, stained with silver nitrate, then sectioned through the middle of the preparation to facilitate the removal of the composite resin restoration. For groups treated with the pre-cure technique, the differences between the enamel leakage values of SBMP-control, CFLB-control and SB1S-control subgroups were significant (p < 0.05). For enamel leakage values of groups treated with the co-cure technique, the differences between the SBMP-control, SB1S-control, CFLB-control and Fuji LC-control subgroups were significant (p < 0.05). For cementum leakage values of groups treated with pre-cure technique, the difference between the CFLB-control and the Fuji, SBMP and SB1S groups was significant (p < 0.05). No significant differences could be detected between the cementum leakage values of groups treated with the co-cure technique (p > 0.05). The differences between the values obtained with application of CFLB with the pre-cure and co-cure techniques at the cementum margins were found to be statistically significant (p = 0.02). No statistically significant differences could be detected between the pre-cure and co-cure values of the other test materials. Generally for every group, cementum microleakage values were greater than enamel microleakage values (p < 0.05). The use of Scotchbond Multi-Purpose, Scotchbond One-Step and Fuji Bond LC with the co-cure technique to decrease the application time did not cause any significant increase in microleakage. Only pre-curing using Clearfil Liner Bond provided better microleakage properties than the other pre-cured adhesives.

Assessment of post-contamination treatments affecting different bonding stages to dentin

PubMed Central

Elkassas, Dina; Arafa, Abla

2016-01-01

Objectives: To assess the effect of cleansing treatments following saliva and blood contamination at different bonding stages to dentin. Materials and Methods: Labial surfaces of 168 permanent maxillary central incisors were ground flat exposing superficial dentin. Specimens were divided into: uncontaminated control (A), contamination after etching (B), contamination after adhesive application (C), contamination after adhesive polymerization (D). Groups were further subdivided according to cleansing treatments into: rinsing (B1, C1, D1), re-etching (B2, D3), sodium hypochlorite application (B3), ethyl alcohol application (C2), acetone application (C3), rinsing and rebonding (D2), re-etching and rebonding (D4). Composite microcylinders were bonded to treated substrates and shear loaded micro-shear bond strength (μSBS) until failure and treated surfaces were examined with scanning electron microscope. Debonded surfaces were classified as adhesive, cohesive or mixed failure. The data were analyzed using one-way ANOVA and Tukey's post hoc test. Results: The μSBS values were ranked as follow; Group B: A > B3 > B2 > B1 > B, Group C: A > C3 > C2 > C1 > C, Group D: A > D4 > D1 = D2 ≥ D3. Debonded surfaces showed adhesive failure in Group B while cohesive failure in Groups C and D. Conclusions: Cleansing treatments differ according to bonding step; re-etching then rebonding suggested if etched substrate or polymerized adhesive were contaminated while acetone application decontaminated affected unpolymerized adhesive. PMID:27403048

Effects of the bisphosphonate alendronate on molars of young rats after lateral luxation.

PubMed

Rothbarth, Cláudia Pires; Bradaschia-Correa, Vivian; Ferreira, Lorraine Braga; Arana-Chavez, Victor Elias

2014-12-01

The bisphosphonate alendronate (ALN) was employed with the aim of investigating its effects on dental and periodontal tissues after lateral luxation of developing molars. Twenty-one-day-old Wistar rats had their second upper molars laterally luxated. Daily 2.5 mg kg(-1) ALN injections started at the day of the luxation; controls received sterile saline solution. The teeth were analyzed 7, 14, and 21 days after the procedure. On the days cited, the maxillae were fixed, decalcified, and embedded in paraffin or Spurr resin. The paraffin sections were stained with H&E, incubated for TRAP histochemistry or immunolabeled for osteopontin (OPN). Spurr ultrathin sections were examined in a transmission electron microscope. After 21 days, the root apex of luxated molars without ALN was wide open and disorganized and also covered by an irregular layer of cellular cementum, which was not observed in ALN-treated animals. Ankylosis sites were observed in ALN rats in both luxated and non-luxated teeth. The TRAP-positive osteoclasts were more numerous in ALN group, despite their latent ultrastructural appearance without the presence of resorption apparatus compared to controls. OPN immunolabeling revealed a thick immunopositive line in the dentin that must be resultant from the moment of the luxation, while ALN-treated specimens did not present alterations in dentin. The present findings indicate that alendronate inhibits some alterations in dentin and cementum formation induced by dental trauma. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Influence of Blood Contamination on Bond Strength of a Self-Etching System

PubMed Central

de Carvalho Mendonça, Ellen Cristina; Vieira, Samuel Nilo; Kawaguchi, Fernando Aparecido; Powers, John; Matos, Adriana Bona

2010-01-01

Objectives: To detect the influence of blood contamination (BC) on the bond strength (BS) of a self-etching bonding system (SES) to enamel and dentine. Methods: 25 human molars were longitudinally sectioned on the mesio-distal axis in order to obtain 50 specimens, which were embedded in acrylic resin. At first, the specimens were ground to expose a flat surface of enamel, and a bond strength test was performed. Afterwards, the samples were ground again in order to obtain a flat surface of dentine. Ten groups (total: n=100) were assigned according to substrate (enamel and dentine), step in the bonding sequence when contamination occurred (before the acidic primer and after the bonding resin), and contamination treatment (dry or rinse and dry procedure). Fresh human blood was introduced either before or after SES application (Clearfil SE Bond) and treated with air drying, or by rinsing and drying following application. Composite resin (Filtek Z-250,3M ESPE) was applied as inverted, truncated cured cones that were debonded in tension. Results: The mean tensile BS values (MPa) for enamel/dentine were 19.4/23.0 and 17.1/10.0 for rinse-and-dry treatment (contamination before and after SES, respectively); while the measurements for the dry treatment, 16.2/23.3 and 0.0/0.0 contamination before and after SES, respectively. Conclusions: It was determined that blood contamination impaired adhesion to enamel and dentine when it occurred after bond light curing. Among the tested contamination treatments, the rinse-and-dry treatment produced the highest bond strength with BC after SES application, but it was not sufficient to recover the BS in the contamination-free group. PMID:20613916

Effects of Chemical Cross-linkers on Caries-affected Dentin Bonding

PubMed Central

Macedo, G.V.; Yamauchi, M.; Bedran-Russo, A.K.

2009-01-01

The achievement of a strong and stable bond between composite resin and dentin remains a challenge in restorative dentistry. Over the past two decades, dental materials have been substantially improved, with better handling and bonding characteristics. However, little attention has been paid to the contribution of collagen structure/stability to bond strength. We hypothesized that the induction of cross-linking in dentin collagen improves dentin collagen stability and bond strength. This study investigated the effects of glutaraldehyde- and grape seed extract-induced cross-linking on the dentin bond strengths of sound and caries-affected dentin, and on the stability of dentin collagen. Our results demonstrated that the application of chemical cross-linking agents to etched dentin prior to bonding procedures significantly enhanced the dentin bond strengths of caries-affected and sound dentin. Glutaraldehyde and grape seed extract significantly increased dentin collagen stability in sound and caries-affected dentin, likely via distinct mechanisms. PMID:19892915

Successful treatment of poison oak dermatitis treated with Grindelia spp. (Gumweed).

PubMed

Canavan, Don; Yarnell, Eric

2005-08-01

Poison oak and related hypersensitivity dermatitides are age-old problems that have historically been treated with herbal medicines before the availability of corticosteroids. Few of these historical therapies have been rigorously investigated. The case presented here provides some insight into the potential efficacy of certain herbs for relieving mild-to-moderate poison ivy dermatitis.

Comprehensive analyses of how tubule occlusion and advanced glycation end-products diminish strength of aged dentin

NASA Astrophysics Data System (ADS)

Shinno, Yuko; Ishimoto, Takuya; Saito, Mitsuru; Uemura, Reo; Arino, Masumi; Marumo, Keishi; Nakano, Takayoshi; Hayashi, Mikako

2016-01-01

In clinical dentistry, since fracture is a major cause of tooth loss, better understanding of mechanical properties of teeth structures is important. Dentin, the major hard tissue of teeth, has similar composition to bone. In this study, we investigated the mechanical properties of human dentin not only in terms of mineral density but also using structural and quality parameters as recently accepted in evaluating bone strength. Aged crown and root dentin (age ≥ 40) exhibited significantly lower flexural strength and toughness than young dentin (age < 40). Aged dentin, in which the dentinal tubules were occluded with calcified material, recorded the highest mineral density; but showed significantly lower flexural strength than young dentin. Dentin with strong alignment of the c-axis in hydroxyapatite exhibited high fracture strength, possibly because the aligned apatite along the collagen fibrils may reinforce the intertubular dentin. Aged dentin, showing a high advanced glycation end-products (AGEs) level in its collagen, recorded low flexural strength. We first comprehensively identified significant factors, which affected the inferior mechanical properties of aged dentin. The low mechanical strength of aged dentin is caused by the high mineral density resulting from occlusion of dentinal tubules and accumulation of AGEs in dentin collagen.

Concept and clinical application of the resin-coating technique for indirect restorations.

PubMed

Nikaido, Toru; Tagami, Junji; Yatani, Hirofumi; Ohkubo, Chikahiro; Nihei, Tomotaro; Koizumi, Hiroyasu; Maseki, Toshio; Nishiyama, Yuichiro; Takigawa, Tomoyoshi; Tsubota, Yuji

2018-03-30

The resin-coating technique is one of the successful bonding techniques used for the indirect restorations. The dentin surfaces exposed after cavity preparation are coated with a thin film of a coating material or a dentin bonding system combined with a flowable composite resin. Resin coating can minimize pulp irritation and improve the bond strength between a resin cement and tooth structures. The technique can also be applied to endodontically treated teeth, resulting in prevention of coronal leakage of the restorations. Application of a resin coating to root surface provides the additional benefit of preventing root caries in elderly patients. Therefore, the coating materials have the potential to reinforce sound tooth ("Super Tooth" formation), leading to preservation of maximum tooth structures.

Advanced Oxidative Protein Products Cause Pain Hypersensitivity in Rats by Inducing Dorsal Root Ganglion Neurons Apoptosis via NADPH Oxidase 4/c-Jun N-terminal Kinase Pathways

PubMed Central

Ding, Ruoting; Sun, Baihui; Liu, Zhongyuan; Yao, Xinqiang; Wang, Haiming; Shen, Xing; Jiang, Hui; Chen, Jianting

2017-01-01

Pain hypersensitivity is the most common category of chronic pain and is difficult to cure. Oxidative stress and certain cells apoptosis, such as dorsal root ganglion (DRG) neurons, play an essential role in the induction and development of pain hypersensitivity. The focus of this study is at a more specific molecular level. We investigated the role of advanced oxidative protein products (AOPPs) in inducing hypersensitivity and the cellular mechanism underlying the proapoptotic effect of AOPPs. Normal rats were injected by AOPPs-Rat serum albumin (AOPPs–RSA) to cause pain hypersensitivity. Primary cultured DRG neurons were treated with increasing concentrations of AOPPs–RSA or for increasing time durations. The MTT, flow cytometry and western blot analyses were performed in the DRG neurons. A loss of mitochondrial membrane potential (MMP) and an increase in intracellular reactive oxygen species (ROS) were observed. We found that AOPPs triggered DRG neurons apoptosis and MMP loss. After AOPPs treatment, intracellular ROS generation increased in a time- and dose-dependent manner, whereas, N-acetyl-L-cysteine (NAC), a specific ROS scavenger could inhibit the ROS generation. Proapoptotic proteins, such as Bax, caspase 9/caspase 3, and PARP-1 were activated, whereas anti-apoptotic Bcl-2 protein was down-regulated. AOPPs also increased Nox4 and JNK expression. Taken together, these findings suggest that AOPPs cause pain hypersensitivity in rats, and extracellular AOPPs accumulation triggered Nox4-dependent ROS production, which activated JNK, and induced DRG neurons apoptosis by activating caspase 3 and PARP-1. PMID:28674486

Advanced Oxidative Protein Products Cause Pain Hypersensitivity in Rats by Inducing Dorsal Root Ganglion Neurons Apoptosis via NADPH Oxidase 4/c-Jun N-terminal Kinase Pathways.

PubMed

Ding, Ruoting; Sun, Baihui; Liu, Zhongyuan; Yao, Xinqiang; Wang, Haiming; Shen, Xing; Jiang, Hui; Chen, Jianting

2017-01-01

Pain hypersensitivity is the most common category of chronic pain and is difficult to cure. Oxidative stress and certain cells apoptosis, such as dorsal root ganglion (DRG) neurons, play an essential role in the induction and development of pain hypersensitivity. The focus of this study is at a more specific molecular level. We investigated the role of advanced oxidative protein products (AOPPs) in inducing hypersensitivity and the cellular mechanism underlying the proapoptotic effect of AOPPs. Normal rats were injected by AOPPs-Rat serum albumin (AOPPs-RSA) to cause pain hypersensitivity. Primary cultured DRG neurons were treated with increasing concentrations of AOPPs-RSA or for increasing time durations. The MTT, flow cytometry and western blot analyses were performed in the DRG neurons. A loss of mitochondrial membrane potential (MMP) and an increase in intracellular reactive oxygen species (ROS) were observed. We found that AOPPs triggered DRG neurons apoptosis and MMP loss. After AOPPs treatment, intracellular ROS generation increased in a time- and dose-dependent manner, whereas, N -acetyl-L-cysteine (NAC), a specific ROS scavenger could inhibit the ROS generation. Proapoptotic proteins, such as Bax, caspase 9/caspase 3, and PARP-1 were activated, whereas anti-apoptotic Bcl-2 protein was down-regulated. AOPPs also increased Nox4 and JNK expression. Taken together, these findings suggest that AOPPs cause pain hypersensitivity in rats, and extracellular AOPPs accumulation triggered Nox4-dependent ROS production, which activated JNK, and induced DRG neurons apoptosis by activating caspase 3 and PARP-1.

Variations in collagen fibrils network structure and surface dehydration of acid demineralized intertubular dentin: effect of dentin depth and air-exposure time.

PubMed

Fawzy, Amr S

2010-01-01

The aim was to characterize the variations in the structure and surface dehydration of acid demineralized intertubular dentin collagen network with the variations in dentin depth and time of air-exposure (3, 6, 9 and 12 min). In addition, to study the effect of these variations on the tensile bond strength (TBS) to dentin. Phosphoric acid demineralized superficial and deep dentin specimens were prepared. The structure of the dentin collagen network was characterized by AFM. The surface dehydration was characterized by probing the nano-scale adhesion force (F(ad)) between AFM tip and intertubular dentin surface as a new experimental approach. The TBS to dentin was evaluated using an alcohol-based dentin self-priming adhesive. AFM images revealed a demineralized open collagen network structure in both of superficial and deep dentin at 3 and 6 min of air-exposure. However, at 9 min, superficial dentin showed more collapsed network structure compared to deep dentin that partially preserved the open network structure. Total collapsed structure was found at 12 min for both of superficial and deep dentin. The value of the F(ad) is decreased with increasing the time of air-exposure and is increased with dentin depth at the same time of air-exposure. The TBS was higher for superficial dentin at 3 and 6 min, however, no difference was found at 9 and 12 min. The ability of the demineralized dentin collagen network to resist air-dehydration and to preserve the integrity of open network structure with the increase in air-exposure time is increased with dentin depth. Although superficial dentin achieves higher bond strength values, the difference in the bond strength is decreased by increasing the time of air-exposure. The AFM probed F(ad) showed to be sensitive approach to characterize surface dehydration, however, further researches are recommended regarding the validity of such approach.

The effect of EDTA, EGTA, EDTAC, and tetracycline-HCl with and without subsequent NaOCl treatment on the microhardness of root canal dentin.

PubMed

Sayin, Taner Cem; Serper, Ahmet; Cehreli, Zafer C; Otlu, Harika G

2007-09-01

The purpose of this study was to evaluate the effect of single and combined use of ethylenediamine tetra acetic acid (EDTA), ethylene glycol bis [b-aminoethylether] N,N,N',N'-tetraacetic acid (EGTA), EDTA plus Cetavlon (EDTAC), tetracycline-HCl, and NaOCl on the microhardness of root canal dentin. The crowns of 30 single-rooted human teeth were discarded at the cementoenamel junction and the roots were bisected longitudinally to obtain root halves (N = 60). The specimens were embedded in autopolymerizing acrylic resin, leaving the root canal dentin exposed. Dentin surfaces were prepared for microhardness test by grinding and polishing. The reference microhardness values of untreated specimens were recorded using a Vicker's microhardness tester at the apical, midroot, and cervical levels of the root canal. Thereafter, the specimens treated with single (test solution only) or combined (test solution, followed by 2.5% NaOCl) versions of the irrigants for 5 minutes. Posttreatment microhardness values were obtained as with initial ones. Statistical comparisons between the test groups and among single and combined treatments were carried out using 2-way ANOVA with repeated measures (P =.05). Comparisons within each group with respect to application regions were made with Friedman's nonparametric 2-way analysis of variance at the same level of significance. All treatment regimens except distilled water significantly decreased the microhardness of the root canal dentin (P < . 05). The single and combined use of EDTA decreased the microhardness of the root canal dentin significantly more than all other treatment regimens (P < .05). Compared with their single-treatment versions, all combined treatment regimens decreased the mean microhardness values significantly (P < .05). A comparison of single and combined treatment regimens revealed significant decreases only for EDTA and EDTA + NaOCl in the coronal region and for EDTAC and EDTAC + NaOCl in the apical and middle regions of the root canal (P < .05). The use of EDTA alone or prior to NaOCl resulted in the maximum decrease in dentin microhardness. The softening effect of subsequent NaOCl treatment was both material and region dependent. However, for combined treatment regimens, subsequent use of NaOCl levels the statistical differences between the regional microhardness values obtained after treatment with EGTA, EDTAC, and tetracycline-HCl.

In vitro transdentinal effect of low-level laser therapy

NASA Astrophysics Data System (ADS)

Oliveira, C. F.; Basso, F. G.; dos Reis, R. I.; Parreiras-e-Silva, L. T.; Lins, E. C.; Kurachi, C.; Hebling, J.; Bagnato, V. S.; de Souza Costa, C. A.

2013-05-01

Low-level laser therapy (LLLT) has been used for the treatment of dentinal hypersensitivity. However, the specific LLL dose and the response mechanisms of these cells to transdentinal irradiation have not yet been demonstrated. Therefore, this study evaluated the transdentinal effects of different LLL doses on stressed odontoblast-like pulp cells MDPC-23 seeded onto the pulpal side of dentin discs obtained from human third molars. The discs were placed in devices simulating in vitro pulp chambers and the whole set was placed in 24-well plates containing plain culture medium (DMEM). After 24 h incubation, the culture medium was replaced by fresh DMEM supplemented with either 5% (simulating a nutritional stress condition) or 10% fetal bovine serum (FBS). The cells were irradiated with doses of 15 and 25 J cm-2 every 24 h, totaling three applications over three consecutive days. The cells in the control groups were removed from the incubator for the same times as used in their respective experimental groups for irradiation, though without activating the laser source (sham irradiation). After 72 h of the last active or sham irradiation, the cells were evaluated with respect to succinic dehydrogenase (SDH) enzyme production (MTT assay), total protein (TP) expression, alkaline phosphatase (ALP) synthesis, reverse transcriptase polymerase chain reaction (RT-PCR) for collagen type 1 (Col-I) and ALP, and morphology (SEM). For both tests, significantly higher values were obtained for the 25 J cm-2 dose. Regarding SDH production, supplementation of the culture medium with 5% FBS provided better results. For TP and ALP expression, the 25 J cm-2 presented higher values, especially for the 5% FBS concentration (Mann-Whitney p < 0.05). Under the tested conditions, near infrared laser irradiation at 25 J cm-2 caused transdentinal biostimulation of odontoblast-like MDPC-23 cells.

Oclacitinib in feline nonflea-, nonfood-induced hypersensitivity dermatitis: results of a small prospective pilot study of client-owned cats.

PubMed

Ortalda, Christian; Noli, Chiara; Colombo, Silvia; Borio, Stefano

2015-08-01

Oclacitinib is a Janus kinase inhibitor that decreases pruritus and lesions in allergic dogs. In cats, it is able to inhibit interleukin-31-induced pruritus; no information is available on its clinical effectiveness. To evaluate the efficacy, ease of administration and tolerability of oclacitinib in feline nonflea-, nonfood-induced hypersensitivity dermatitis. Cats >12 months of age and >3 kg body weight with a diagnosis of nonflea-, nonfood-induced hypersensitivity dermatitis were treated with oclacitinib, 0.4-0.6 mg/kg orally (p.o.) twice daily for 2 weeks, then once daily for an additional 14 days. Clinical lesions were evaluated with the Scoring Feline Allergic Dermatitis (SCORFAD) system and pruritus was evaluated with a 10-cm-long visual analog scale (VAS) before and at the end of the study. Owners assessed global efficacy, ease of administration and tolerability with a four-point scale. Twelve cats were treated with a mean initial oclacitinib dose of 0.47 mg/kg p.o. twice daily. There was good improvement in SCORFAD and VAS pruritus scores in five of 12 cases, while the other cats were unchanged, deteriorated or dropped out due to treatment failure. Owners scored global efficacy as good/excellent in four of 12 cases and ease of administration and tolerability as good/excellent in 10 of 12. Oclacitinib at 0.4-0.6 mg/kg p.o. may be an effective and safe drug for some cats with nonflea-, nonfood-induced hypersensitivity dermatitis. Further studies are needed to identify the most effective dose range for this species. © 2015 ESVD and ACVD.

Multinational experience with hypersensitivity drug reactions in Latin America.

PubMed

Jares, Edgardo José; Sánchez-Borges, Mario; Cardona-Villa, Ricardo; Ensina, Luis Felipe; Arias-Cruz, Alfredo; Gómez, Maximiliano; Barayazarra, Susana; Bernstein, Jonathan A; Serrano, Carlos D; Cuello, Mabel Noemi; Morfin-Maciel, Blanca María; De Falco, Alicia; Cherrez-Ojeda, Iván

2014-09-01

Epidemiologic drug allergy data from Latin America are scarce, and there are no studies on specific procedures focusing on this topic in Latin America. To assess the clinical characteristics and management of hypersensitivity drug reactions in different Latin American countries. An European Network of Drug Allergy questionnaire survey was implemented in 22 allergy units in 11 Latin American countries to report on consecutive patients who presented with a suspected hypersensitivity drug reaction. Each unit used its own protocols to investigate patients. Included were 868 hypersensitivity drug reactions in 862 patients (71% of adults and elderly patients were women and 51% of children were girls, P = .0001). Children presented with less severe reactions than adults and elderly patients (P < .0001). Urticaria and angioedema accounted for the most frequent clinical presentations (71%), whereas anaphylaxis was present in 27.3% of cases. There were no deaths reported. Nonsteroidal anti-inflammatory drugs (52.3%), β-lactam antibiotics (13.8%), and other antibiotics (10.1%) were the drugs used most frequently. Skin prick tests (16.7%) and provocation tests (34.2%) were the study procedures most commonly used. A large proportion of patients were treated in the emergency department (62%) with antihistamines (68%) and/or corticosteroids (53%). Only 22.8% of patients presenting with anaphylaxis received epinephrine. Nonsteroidal anti-inflammatory drugs and antibiotics were the drugs used in at least 75% of patients. More than half the reactions were treated in the emergency department, whereas epinephrine was administered in fewer than 25% of patients with anaphylaxis. Dissemination of guidelines for anaphylaxis among primary and emergency department physicians should be encouraged. Copyright © 2014 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Influence of solvents on the bond strength of resin sealer to intraradicular dentin after retreatment.

PubMed

Palhais, Marcelo; Sousa-Neto, Manoel Damião; Rached-Junior, Fuad Jacob Abi; Amaral, Mariana Carvalho de Andrade; Alfredo, Edson; Miranda, Carlos Eduardo Saraiva; Silva-Sousa, Yara Teresinha Corrêa

2017-01-26

This study evaluated the removal of filling material with ProTaper Universal Rotary Retreatment system (PTR) combined with solvents and the influence of solvents on the bond strength (PBS) of sealer to intraradicular dentin after canal reobturation. Roots were endodontically treated and distributed to five groups (n = 12). The control group was not retreated. In the four experimental groups, canals were retreated with PTR alone or in combination with xylol, orange oil, and eucalyptol. After filling material removal, two specimens of each group were analysed by SEM and µCT to verify the presence of filling remnants on root canal walls. The other roots were reobturated and sectioned in 1-mm-thick dentin slices that were subjected to the push-out test. Data were analysed by two-way ANOVA and Tukey's test (α = 0.05). SEM and µCT analysis revealed that all retreatment techniques left filling remnants on canal walls. The control group (3.47 ± 1.21) presented significantly higher (p < 0.05) PBS than the experimental groups. The groups retreated with PTR alone (2.59 ± 0.99) or combined with xylol (2.54 ± 0.77) and orange oil (2.32 ± 0.93) presented similar bond strength (p > 0.05), and differed significantly from the group with eucalyptol (1.89 ± 0.63). The solvents reduced the PBS of the sealer to dentin and no retreatment technique promoted complete removal of filling material.

Comparative clinical evaluation of the immediate and late analgesic effect of GaAlAs diode lasers of 830 and 660 nm in the treatment of dentine pain: preliminary results

NASA Astrophysics Data System (ADS)

Ladalardo, Thereza C.; Mangabeira Albernaz, Pedro L.; Brugnera, Aldo, Jr.; Zanin, Fatima A. A.; Siqueira, Jose T.; Pinheiro, Antonio L. B.

2002-06-01

In this comparative clinical study, we aimed at evaluating the immediate and late analgesic effect of GaAlAs diode lasers of 660 nm and 830 nm in treatment of dentine pain. We used GaAlAs diode lasers of 660 nm and 830 nm with 35 mW, continuous wave emission, spot size 1 mm2 and a dosage of 4 joules/cm2 applied to the cervical dentine surface. In total 4 treatment sessions were performed at intervals of 7 days in a period of 4 consecutive weeks. A total of 40 teeth treated were divided into two groups comprising 20 teeth each: one group irradiated with a 660 nm wavelength laser, and the other one with a 830 nm wavelength laser. By means of a quantitative visual analogue scale (V.A.S.), we measured the sensitive responses to cold stimulus pre- treatment, and at a follow-up period of 15 and 30 minutes post-treatment in both groups in order to evaluate the immediate analgesic effect. The late effect was evaluated at a follow-up period of 15 and 30 days. Using the GaAlAs diode laser of 660 nm wavelength resulted in better levels of dentine desensitization, at both immediate and late analgesic effect analysis compared with the use of the GaAlAs diode laser of 830 nm wavelength.

Comparative Evaluation of the Etching Pattern of Er,Cr:YSGG & Acid Etching on Extracted Human Teeth-An ESEM Analysis

PubMed Central

Mazumdar, Dibyendu; Ranjan, Shashi; Krishna, Naveen Kumar; Kole, Ravindra; Singh, Priyankar; Lakiang, Deirimika; Jayam, Chiranjeevi

2016-01-01

Introduction Etching of enamel and dentin surfaces increases the surface area of the substrate for better bonding of the tooth colored restorative materials. Acid etching is the most commonly used method. Recently, hard tissue lasers have been used for this purpose. Aim The aim of the present study was to evaluate and compare the etching pattern of Er,Cr:YSGG and conventional etching on extracted human enamel and dentin specimens. Materials and Methods Total 40 extracted non-diseased teeth were selected, 20 anterior and 20 posterior teeth each for enamel and dentin specimens respectively. The sectioned samples were polished by 400 grit Silicon Carbide (SiC) paper to a thickness of 1.0 ± 0.5 mm. The enamel and dentin specimens were grouped as: GrE1 & GrD1 as control specimens, GrE2 & GrD2 were acid etched and GrE3 & GrD3 were lased. Acid etching was done using Conditioner 36 (37 % phosphoric acid) according to manufacturer instructions. Laser etching was done using Er,Cr:YSGG (Erbium, Chromium : Ytrium Scandium Gallium Garnet) at power settings of 3W, air 70% and water 20%. After surface treatment with assigned agents the specimens were analyzed under ESEM (Environmental Scanning Electron Microscope) at X1000 and X5000 magnification. Results Chi Square and Student “t” statistical analysis was used to compare smear layer removal and etching patterns between GrE2-GrE3. GrD2 and GrD3 were compared for smear layer removal and diameter of dentinal tubule opening using the same statistical analysis. Chi-square test for removal of smear layer in any of the treated surfaces i.e., GrE2-E3 and GrD2-D3 did not differ significantly (p>0.05). While GrE2 showed predominantly type I etching pattern (Chi-square=2.78, 0.05

0.10) and GrE3 showed type III etching (Chi-square=4.50, p<0.05). The tubule diameters were measured using GSA (Gesellschaft fur Softwareentwicklung und Analytik, Germany) image analyzer and the ‘t’ value of student ‘t’ test was 18.10 which was a highly significant result (p<.001). GrD2 had a mean dentinal tubule diameter of 2.78μm and GrD3 of 1.09μm. Conclusion The present study revealed type I etching pattern after acid etching, while type III etching pattern in enamel after laser etching. The lased dentin showed preferential removal of intertubular dentin while acid etching had more effect on the peritubular dentin. No significant differences was observed in removal of smear layer between the acid etched and lased groups. Although diameter of the exposed dentinal tubules was lesser after lased treatment in comparison to acid etching, further long term in vivo studies are needed with different parameters to establish the usage of Er,Cr:YSGG as a sole etching agent. PMID:27437337

Different methods of dentin processing for application in bone tissue engineering: A systematic review.

PubMed

Tabatabaei, Fahimeh Sadat; Tatari, Saeed; Samadi, Ramin; Moharamzadeh, Keyvan

2016-10-01

Dentin has become an interesting potential biomaterial for tissue engineering of oral hard tissues. It can be used as a scaffold or as a source of growth factors in bone tissue engineering. Different forms of dentin have been studied for their potential use as bone substitutes. Here, we systematically review different methods of dentin preparation and the efficacy of processed dentin in bone tissue engineering. An electronic search was carried out in PubMed and Scopus databases for articles published from 2000 to 2016. Studies on dentin preparation for application in bone tissue engineering were selected. The initial search yielded a total of 1045 articles, of which 37 were finally selected. Review of studies showed that demineralization was the most commonly used dentin preparation process for use in tissue engineering. Dentin extract, dentin particles (tooth ash), freeze-dried dentin, and denatured dentin are others method of dentin preparation. Based on our literature review, we can conclude that preparation procedure and the size and shape of dentin particles play an important role in its osteoinductive and osteoconductive properties. Standardization of these methods is important to draw a conclusion in this regard. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2616-2627, 2016. © 2016 Wiley Periodicals, Inc.

Relationship between water status in dentin and interfacial morphology in all-in-one adhesives.

PubMed

Yoshida, Eiji; Uno, Sigeru; Nodasaka, Yoshinobu; Kaga, Msayuki; Hirano, Susumu

2007-05-01

All-in-one adhesive systems have been recently developed to simplify bonding procedures. The adhesives containing acidic resin monomers generate a relatively thin bonding zone between dentin and composite. This zone may be left acidic and permeable when polymerization is poor. In this study, the effect of water contained in dentin on the quality of the bonding interface was morphologically investigated for all-in-one adhesives. Intact coronal dentin (hydrated dentin), desiccated coronal dentin (dehydrated dentin), caries-affected dentin (CAD) and resin composites were used for adherends to assess the effects of water contained in dentin on the ultra-structures of bonding interfaces created with two all-in-one adhesives and a resin composite. The bonding interfaces were observed under TEM without demineralization. Voids of various sizes were found at the bottom of the adhesive resin layers along the bonding interface of hydrated dentin, while dehydrated dentin, CAD and resin composites did not generate voids. The results showed that the voids were possibly formed by water that had penetrated from the underlying dentin. When the adherend contains little water, the formation of voids will not occur. It was verified that a phenomenon of void formation would not occur in a clinical situation in which caries-affected dentin is mainly subjected to adhesive practices.

A review of the regenerative endodontic treatment procedure

PubMed Central

Lee, Bin-Na; Moon, Jong-Wook; Chang, Hoon-Sang; Hwang, In-Nam; Oh, Won-Mann

2015-01-01

Traditionally, apexification has been used to treat immature permanent teeth that have lost pulp vitality. This technique promotes the formation of an apical barrier to close the open apex so that the filling materials can be confined to the root canal. Because tissue regeneration cannot be achieved with apexification, a new technique called regenerative endodontic treatment was presented recently to treat immature permanent teeth. Regenerative endodontic treatment is a treatment procedure designed to replace damaged pulp tissue with viable tissue which restores the normal function of the pulp-dentin structure. After regenerative endodontic treatment, continued root development and hard tissue deposition on the dentinal wall can occur under ideal circumstances. However, it is difficult to predict the result of regenerative endodontic treatment. Therefore, the purpose of this study was to summarize multiple factors effects on the result of regenerative endodontic treatment in order to achieve more predictable results. In this study, we investigated the features of regenerative endodontic treatment in comparison with those of other pulp treatment procedures and analyzed the factors that have an effect on regenerative endodontic treatment. PMID:26295020

Adhesive phase separation at the dentin interface under wet bonding conditions.

PubMed

Spencer, Paulette; Wang, Yong

2002-12-05

Under in vivo conditions, there is little control over the amount of water left on the tooth and, thus, there is the danger of leaving the dentin surface so wet that the bonding resin undergoes physical separation into hydrophobic and hydrophilic-rich phases. The purpose of this study was to investigate phase separation in 2,2-bis[4(2-hydroxy-3-methacryloyloxy-propyloxy)-phenyl] propane (BisGMA)-based adhesive using molecular microanalysis and to examine the effect of phase separation on the structural characteristics of the hybrid layer. Model BisGMA/HEMA (hydroxyethl methacrylate) mixtures with/without ethanol and commercial BisGMA-based adhesive (Single Bond) were combined with water at concentrations from 0 to 50 vol%. Macrophase separation in the BisGMA/HEMA/water mixtures was detected using cloud point measurements. In parallel with these measurements, the BisGMA/HEMA and adhesive/water mixtures were cast as films and polymerized. Molecular structure was recorded from the distinct features in the phase-separated adhesive using confocal Raman microspectroscopy (CRM). Human dentin specimens treated with Single Bond were analyzed with scanning electron microscopy (SEM) and CRM mapping across the dentin/adhesive interface. The model BisGMA/HEMA mixtures with ethanol and the commercial BisGMA-based adhesive experienced phase separation at approximately 25 vol% water. Raman spectra collected from the phase-separated adhesive indicated that the composition of the particles and surrounding matrix material was primarily BisGMA and HEMA, respectively. Based on SEM analysis, there was substantial porosity at the adhesive interface with dentin. Micro-Raman spectral analysis of the dentin/adhesive interface indicates that the contribution from the BisGMA component decreases by nearly 50% within the first micrometer. The morphologic results in corroboration with the spectroscopic data suggest that as a result of adhesive phase separation the hybrid layer is not an impervious 3-dimensional collagen/polymer network but a porous web characterized by hydrophobic BisGMA-rich particles distributed in a hydrophilic HEMA-rich matrix. Copyright 2002 Wiley Periodicals, Inc.

X-linked hypophosphatemia: the mutant gene is expressed in teeth as well as in kidney.

PubMed Central

Shields, E D; Scriver, C R; Reade, T; Fujiwara, T M; Morgan, K; Ciampi, A; Schwartz, S

1990-01-01

Mutation at a locus (HPDR) on the X chromosome (McKusick 30780 [HPDR1]; 30781 [HPDR2]) causes impaired renal phosphate transport, hypophosphatemia, and an associated impairment in the process of mineralization in bone and teeth (X-linked hypophosphatemia [XLH]). We measured the dental pulp profile area (PRATIO [= pulp area/tooth area]) and serum phosphorus (Pi) values in uniformly treated XLH patients (six males, 81 teeth, 1,457 Pi values; 11 females, 129 teeth, 1,439 Pi values). Serum Pi values, reflecting the metabolic environment of tooth development, were obtained by repeated measurement between 1 mo and 26 years of age during treatment. PRATIO values calculated from standardized Rinn radiographs were used as outcome measurements of tooth development in XLH patients and in age-matched controls (12 males, 100 teeth; 27 females, 275 teeth). Age-dependent serum Pi values were not different in the treated XLH males and females. In teeth forming primary dentin there was no gene dosage effect on PRATIO values apparent in subjects below 15 years of age. However, in teeth forming secondary dentin a gene dosage was found in the subjects aged 15 to 25 years: XLH male teeth (n = 65) mean +/- SD = 0.163 +/- 0.046; XLH female teeth (n = 75) mean +/- SD = 0.137 +/- 0.039; control teeth (n = 209) mean +/- SD = 0.116 +/- 0.023; (higher PRATIO values mean less development or mineralization of secondary dentin); differences in these PRATIO values (males vs. female and XLH vs. control) were significant by mixed-model analysis of variance.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2155529

Pulpal reaction to a dental adhesive in deep human cavities.

PubMed

Torstenson, B

1995-08-01

In the last years several dental adhesives have been developed. They are supposed to chemically adhere to dentin and a liner to protect the pulp is not used. The aim of this study was to compare the short-term pulpal reaction, in an intra-toothpair study, between a dental adhesive, Scotchbond 2, and a lining system, Tubulitec, in combination with P-50 in surface-sealed cavities. Deep buccal cavities in 16 human pairs of premolars, 32 teeth, were restored in vivo with a light cured composite resin, P-50. To minimize bacterial contamination all cavities were treated with a cleanser, Tubulicid, and the cavities were surface-sealed with temporary cement, Coltosol. One tooth in each pair, the test, was treated with Scotchprep Dentin Primer and Scotchbond 2 Light Cure Dental Adhesive. In the other tooth in the pair, the control, Tubulitec Primer and Liner were used. The teeth were extracted after 6-14 days. The sections were evaluated for degree of inflammation and the presence of bacteria. Irrespective of treatment of dentin the majority of teeth, 23, including one pulpal exposure, revealed no inflammation or a few inflammatory cells. In four test teeth, including one pulpal exposure, and two controls, growth of bacteria was found on the cavity walls and slight or moderate inflammation was seen in the corresponding pulps. In one test and two control teeth slight inflammation was seen but no bacteria could be detected. In the absence of bacteria Scotchbond 2 did not seem to irritate the pulp.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro study of root fracture treated by CO2 laser and DP-bioactive glass paste.

PubMed

Wang, Yin-Lin; Lee, Bor-Shiunn; Tseng, Ching-Li; Lin, Feng-Huei; Lin, Chun-Pin

2008-01-01

An ideal material has yet to be discovered that can successfully treat vertical root fracture. Therefore, the purpose of this study was to use a continuous-wave CO2 laser of medium-energy density to fuse DP-bioactive glass paste (DPGP) to vertical root fracture. The DP-bioglass powder was based on a Na2O-CaO-SiO2-P2O5 system and it was mixed with phosphoric acid (65% concentration) with a powder/liquid ratio of 2 g/4 mL to form DPGP. The interaction of DPGP and dentin was analyzed by means of X-ray diffractometer (XRD) and differential thermal analysis/thermogravimetric analysis (DTA/TGA). Root fracture line was filled with DPGP followed by CO2 laser irradiation and the result was examined by scanning electron microscopy (SEM). The main crystal phase of DPGP was monocalcium phosphate monohydrate (Ca(H2PO4)2.H2O) and the phase transformed to dicalcium phosphate dihydrate (CaHPO4.2H2O) after mixing DPGP with dentin powder (DPG-D). Additionally, gamma-Ca2P2O7 and beta-Ca2P2O7 were identified when DPG-D was lased by CO2 laser. The reaction temperature was between 500 degrees C and 1100 degrees C. SEM results demonstrated that the fracture line was effectively sealed by DPGP. The chemical reaction of DPGP and dentin indicated that DPGP combined with CO2 laser is a potential regimen for the treatment of vertical root fracture.

Peroxisome proliferator-activated receptor-gamma agonist rosiglitazone attenuates postincisional pain by regulating macrophage polarization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hasegawa-Moriyama, Maiko, E-mail: hase-mai@m3.kufm.kagoshima-u.ac.jp; Ohnou, Tetsuya; Godai, Kohei

Highlights: Black-Right-Pointing-Pointer Rosiglitazone attenuated postincisional pain. Black-Right-Pointing-Pointer Rosiglitazone alters macrophage polarization to F4/80{sup +}CD206{sup +} M2 macrophages at the incisional sites. Black-Right-Pointing-Pointer Transplantation of rosiglitazone-treated macrophages produced analgesic effects. -- Abstract: Acute inflammation triggered by macrophage infiltration to injured tissue promotes wound repair and may induce pain hypersensitivity. Peroxisome proliferator-activated receptor {gamma} (PPAR){gamma} signaling is known to regulate heterogeneity of macrophages, which are often referred to as classically activated (M1) and alternatively activated (M2) macrophages. M1 macrophages have considerable antimicrobial activity and produce a wide variety of proinflammatory cytokines. In contrast, M2 macrophages are involved in anti-inflammatory and homeostatic functionsmore » linked to wound healing and tissue repair. Although it has been suggested that PPAR{gamma} agonists attenuate pain hypersensitivity, the molecular mechanism of macrophage-mediated effects of PPAR{gamma} signaling on pain development has not been explored. In this study, we investigated the link between the phenotype switching of macrophage polarization induced by PPAR{gamma} signaling and the development of acute pain hypersensitivity. Local administration of rosiglitazone significantly ameliorated hypersensitivity to heat and mechanical stimuli, and paw swelling. Consistent with the down-regulation of nuclear factor {kappa}B (NF{kappa}B) phosphorylation by rosiglitazone at the incisional sites, the number of F4/80{sup +}iNOS{sup +} M1 macrophages was decreased whereas numbers of F4/80{sup +}CD206{sup +} M2 macrophages were increased in rosiglitazone-treated incisional sites 24 h after the procedure. In addition, gene induction of anti-inflammatory M2-macrophage-associated markers such as arginase1, FIZZ1 and interleukin (IL)-10 were significantly increased, whereas M1-macrophage-related molecules such as integrin {alpha}X, IL-1{beta}, MIP2{alpha} and leptin were decreased at rosiglitazone-treated incisional sites. Moreover, transplantation of rosiglitazone-treated peritoneal macrophages into the incisional sites significantly attenuated hyperalgesia. We speculate that local administration of rosiglitazone significantly alleviated the development of postincisional pain, possibly through regulating macrophage polarity at the inflamed site. PPAR{gamma} signaling in macrophages may be a potential therapeutic target for the treatment of acute pain development.« less

Common allergies do not influence the prevalence of cutaneous hypersensitivity reactions to antiepileptic drugs.

PubMed

Bosak, Magdalena; Porębski, Grzegorz; Słowik, Agnieszka; Turaj, Wojciech

2017-09-01

The aim of the study was to establish whether the presence of common allergies increases the risk of drug-related hypersensitivity reactions among patients with epilepsy treated with antiepileptic drugs (AEDs). We studied 753 patients with epilepsy seen in tertiary outpatient epilepsy clinic. We obtained data related to epilepsy type, past and ongoing treatment with AEDs, occurrence of maculopapular exanthema or more serious cutaneous adverse reactions (Stevens-Johnson syndrome - SJS) and their characteristics. We noted an occurrence of allergic reactions unrelated to treatment with AED, including rash unrelated to AED, bronchial asthma, persistent or seasonal allergic rhinitis, atopic dermatitis, rash after specific food and other allergic reactions. There were 61 cases of AED-related cutaneous hypersensitivity reaction (including 3 cases of SJS) noted in association with 2319 exposures to AEDs (2.63%) among 55 out of 753 patients (7.3%). Cutaneous hypersensitivity reaction to AED was most commonly noted after lamotrigine (12.1%), carbamazepine (5.4%) and oxcarbazepine (4.1%). Prevalence of allergic reactions unrelated to AED was similar between patients with and without AED-related cutaneous hypersensitivity reaction (rash unrelated to AED: 16.4% vs. 10.2%; bronchial asthma: 1.8% vs. 0.1%; persistent allergic rhinitis: 7.3% vs. 10.2%; seasonal allergic rhinitis: 7.3% vs. 11.7%; atopic dermatitis: 0 vs. 0.7%; rash after specific food: 5.4% vs. 6.4%; other allergic reactions: 5.4% vs. 5.2%, respectively; P>0.1 for each difference). Presence of common allergies is not a significant risk factor for AED-related cutaneous hypersensitivity reaction among patients with epilepsy. Copyright © 2017 Elsevier B.V. All rights reserved.

Randomized, Controlled Trial of Dexamethasone Versus Dexamethasone Plus Hydrocortisone as Prophylaxis for Hypersensitivity Reactions Due to Paclitaxel Treatment for Gynecologic Cancer.

PubMed

Jeerakornpassawat, Dhammapoj; Suprasert, Prapaporn

2017-10-01

The aim of this study was to assess intravenous hydrocortisone (HCT) added to standard dexamethasone (DXM) prophylaxis for paclitaxel-associated hypersensitivity reactions (HSRs). Paclitaxel naives scheduled for 6 cycles of paclitaxel (plus platinum) were randomized to DXM alone (20 mg intravenously [IV]) versus DXM plus HCT (100 mg IV) as premedication including chlorpheniramine (10 mg IV), diphenhydramine (25 mg orally), and ranitidine (50 mg IV) 30 minutes before infusion. Clinic nurses observed for HSRs. Groups were well balanced for cancer type, stage, drug allergy, chemotherapy naivete, mean age, body mass index, and paclitaxel dose. The 44 DXM controls underwent 213 cycles and the 42 investigational DXM plus HCT group 192 per protocol cycles. Hypersensitivity reactions were observed among 9 (4.2%) DXM only cycles compared with 1 (0.5%) among DXM plus HCT cycles (P = 0.022). Hypersensitivity reactions occurred in 8 (18%) DXM only patients and in 1 (2.4%) among those correctly receiving DXM plus HCT (P = 0.030). All HSRs occurred in cycles 1 to 3, within 10 to 40 minutes after infusion initiation, and peaked in cycle 2 (5/39) for DXM recipients and in cycle 3 (1/30) for DXM plus HCT. Hypersensitivity reaction severity was grade 1 in 3 DXM only recipients and grade 2 in 6 DXM and 1 DXM plus HCT. A sole grade 3 HSR was in an intention-to-treat DXM-HCT patient, who erroneously received no HCT. Hypersensitivity reaction symptoms were facial flushing (8 episodes), dyspnea (7), palmar rash (1), and transient hypotension (1). Paclitaxel infusion was suspended for treatment of HSRs; in all cases, symptoms mitigated and infusion successfully restarted for the remaining dose. Adding HCT to routine DXM prophylaxis significantly decreased paclitaxel HSR frequency.

Cuspal reinforcement in endodontically treated molars.

PubMed

Uyehara, M Y; Davis, R D; Overton, J D

1999-01-01

This in vitro study compared the ability of horizontal pins and a dental adhesive to reinforce the facial cusps of endodontically treated mandibular molars. Seventy-two mandibular molars were divided into six groups and mounted in acrylic blocks (n = 12). In Groups 1-5 standardized endodontic access and instrumentation in the coronal one-third of each root canal were completed. In Groups 1-4 the lingual cusps were reduced, leaving the buccal cusps intact. The facial cusps of the teeth in each group received one of the following modes of reinforcement: Group 1--no reinforcement; Group 2--dentin adhesive (Amalgambond Plus); Group 3--two horizontal TMS Minim pins; Group 4--two horizontal TMS Minim pins and Amalgambond Plus. Teeth in Group 5 were prepared for and restored with a complete cuspal coverage amalgam restoration using four vertical TMS Minim pins. Group 6 consisted of intact natural teeth. Using an Instron Universal Testing Machine, the lingual slope of the facial cusp of each specimen was loaded to failure using a compressive force applied at an angle 60 degrees to the long axis of the tooth. The mean fracture strengths for all groups were analyzed using a one-way ANOVA and Student-Newman-Keuls multiple range test (alpha = 0.05). Fracture patterns and modes of failure were also evaluated. The intact teeth (Group 6) were significantly more fracture resistant than all other groups, with the exception of Group 4 (combination of pins and adhesive). Group 1 (non-reinforced teeth) was significantly weaker than all other groups. Groups 2-4 (specimens with reinforced cusps) were not significantly different from each other. The use of horizontal pins or a combination of horizontal pins plus dentin adhesive for cuspal reinforcement resulted in significantly more teeth demonstrating favorable fracture patterns than did the use of adhesives alone. The buccal cusps of endodontically treated mandibular molars reinforced with a combination of horizontal pins and dentin adhesive were not significantly weaker than intact teeth. Of the restored teeth, those which had buccal cusps reinforced with horizontal pins and those treated with complete cuspal coverage amalgam restorations exhibited the most favorable restorative prognosis following cusp fracture.

Mineral Apposition Rates in Coronal Dentine of Mandibular First Molars in Soay Sheep: Results of a Fluorochrome Labeling Study.

PubMed

Kahle, Patricia; Witzel, Carsten; Kierdorf, Uwe; Frölich, Kai; Kierdorf, Horst

2018-05-01

We studied the spatio-temporal variation of mineral apposition rate (MAR) in postnatally formed coronal dentine of mandibular first molars from Soay sheep repeatedly injected with different fluorochromes. MAR declined along the cuspal to cervical crown axis, and from early to late formed dentine, that is, from the dentine at the enamel-dentine-junction (EDJ) to the dentine adjacent to the dentine-pulp-interface (DPI). Highest mean MARs (about 21 µm/day) were recorded in cuspal dentine formed in the period of 28-42 days after birth. Lowest values (<2 µm/day) were recorded in late-formed (secondary) dentine close to the DPI. The high MARs recorded in the dentine of the cuspal crown portions enable the formation of a large tooth crown within a relatively short period of less than one year. The established MARs in the dentine of the different crown portions of sheep molars will allow a precise determination of the timing of stress events affecting dentine formation. They are also helpful for devising sampling protocols in studies of trace element or stable isotope distributions in sheep dentine aimed at assessing temporal variation of incorporation into forming dentine. Such data are useful in a variety of contexts, including, for example, the exposure to pollutants and the reconstruction of husbandry practices or feeding regimes. Anat Rec, 301:902-912, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Effect of Dimethyl Sulfoxide on Bond Strength of a Self-Etch Primer and an Etch and Rinse Adhesive to Surface and Deep Dentin.

PubMed

Sharafeddin, Farahnaz; Salehi, Raha; Feizi, Negar

2016-09-01

Composite bond to dentin is crucial in many clinical conditions particularly in deep cavities without enamel margins due to insufficient penetration of adhesive into demineralized dentin. The aim of this study was to assess the shear bond strength (SBS) of a methacrylate-based and a silorane-based composite resin to surface and deep dentin after pretreatment with dimethyl sulfoxide (DMSO). Eighty extracted human premolars were randomly divided into two groups of flat occlusal dentin with different cuts as A: surface group (sections just below the dentinoenamel junction (DEJ) and B: deep group (2 mm below DEJ). Each group was randomly assigned to 4 subgroups and their samples were restored with Adper Single bond (ASB) and Filtek Z350 or Silorane system Adhesive (SA) and Filtek P90 composite resins, using a 3×3mm cylindrical plastic mold. following these steps , the subgroups were assigned as SubgroupA 1 : surface dentin+ Silorane System Primer (SSP)+ Silorane System Bonding (SSB)+ P90; Subgroup A 2 : surface dentin+ 37% etchant (E37%) + Adper Single Bond (ASB)+ Z350; Subgroup A 3 : surface dentin+ DMSO+ SSP+ SSB+ P90; Subgroup A 4 : surface dentin+ E37%+ DMSO+ ASB+ Z350; Subgroup B 1 : deep dentin+ SSP+ SSB+ P90; Subgroup B 2 : deep dentin+ E37%+ ASB+ Z350; Subgroup B 3 : deep dentin+ DMSO+ SSP+ SSB+ P90; Subgroup B 4 :dentin +E37% +DMSO +ASB +Z350. The specimens were thermocycled at 5± 2/55± 2°C for 1000 cycles and then tested for SBS. Using DMSO as dentin conditioner increased SBS of ASB to deep dentin (p< 0.001) and SBS of SA to surface dentin (p= 0.003) but had no effect on SBS of SA to deep dentin (p= 1.00). The ability of DMSO to increase SBS of ASB to deep dentin provides a basis for improving bonding of this composite resin in deep cavities.

An in vitro assessment of the effect of load and pH on wear between opposing enamel and dentine surfaces.

PubMed

Ranjitkar, Sarbin; Kaidonis, John A; Townsend, Grant C; Vu, Anh M; Richards, Lindsay C

2008-11-01

Previous in vitro studies have described the wear characteristics of specimens in which enamel has been opposed to enamel and dentine opposed to dentine. The aim of this study was to assess the characteristics of wear between specimens in which enamel was opposed to dentine at loads simulating attrition and at pH values simulating different erosive environments. It was hypothesized that enamel would wear more slowly than dentine under all conditions. Opposing enamel and dentine specimens from 57 human third molar teeth were worn in electromechanical machines with various loads (32, 62 and 100 N) and lubricants (pH 1.2, 3.0 and 6.1). Tooth wear was quantified by measuring reduction in dentine volume over time using a 3D profilometer. Qualitative assessment was also carried out using scanning electron microscopy. Dentine wear increased with increasing load, and dentine wear was faster at pH 1.2 than at pH 3.0 or 6.1 for all loads tested. Interestingly, enamel wore more rapidly than dentine at pH 1.2 under all loads. At pH values of 3.0 and 6.1, enamel wear rates were not measurably different from zero and they were less than wear rates for opposing dentine specimens at all loads. Micrographic assessment showed extensive surface destruction of dentine wear facets due to erosion at pH 1.2. Dentine wear facets were smoother at pH 3.0 that at pH 6.1. When enamel wears against dentine in an acidic environment enamel will wear more rapidly at very low pH, while under less acid conditions dentine will wear faster than enamel.

[Effects of different surface modifications on micro-structure and adhesion of zirconia ceramic: an in vitro study].

PubMed

Siwen, Li; Shishi, Li; Yanhong, Wang; Hongmei, Ma

2017-02-01

This study evaluated the effect of different mechanical-chemical surface treatments on the characteristics, microstructure, and composition of zirconia ceramics and on the zirconia-dentin adhesion. The sintered commercial zirconia blocks (IPS e.max ZirCAD) were sectioned into 126 beams (6 mm×6 mm×5 mm) and randomly assigned to seven experimental groups (n=18). The zirconia block specimens were further treated as follows: (A) untreated, as control; (B) sandblasted with 50 μm Al2O3; (C) sandblasted with 50 μm Al2O3+30 μm silica powder; (D) sandblasted with 50 μm Al2O3+30% silica-sol coating; (E) sandblasted with 110 μm Al2O3; (F) sandblasted with 110 μm Al2O3+30 μm silica powder; and (G) sandblasted with 110 μm Al2O3+30% silica-sol coating. The surface roughness (Ra) of zirconia ceramics using X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX) after seven surface treatments was analyzed. Seventy specimens of dentin surfaces were prepared. A dual-cure resin cement was applied into zirconia surfaces with its corresponding adhesive components to dentin. Shear bond strength (SBS) of each sample was measured using a universal testing machine. The data were analyzed by ANOVA using SPSS 17.0 software. Ra of zirconia were significantly different compared with the control group (P<0.05). The crystalline transformation from tetragonal phase to monoclinic phase was observed after surface modification. Monoclinic volume content of the heat-treated group was highest than that in other groups. The content of element Si in the heat-treated group was higher than that in other treatment groups accompanied by a decrease in elements Zr, Y, and Hf after being treated by two silica-coating methods. Air abrasion significantly increased the micro-cracks in the ceramic surface and caused the grain boundaries to disappear. A serious shrinkage of the thin silica film can be observed after sintering procedure. This process induced cracks and the film to strip away slightly from the surfaces of Y-TZP substrate. The SBS values from large to small were F and G groups, C and D groups, B and E groups (P<0.05), and control group (P<0.05). Alumina sandblasting, silica powder abrasion, and silica-sol coating affect the surface morphology, structure, and composition of the tooth. This effect can also achieve the improved micro-mechanical interlocking or chemical bonding and finally increase the bond strength between zirconia and tooth. Alumina sandblasting followed by silica coating is an effective technique to increase the bonding strength between the zirconia ceramic and dentin.
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Porous zirconia ceramic as an alternative to dentin for in vitro dentin barriers cytotoxicity test.

PubMed

Hu, Meng-Long; Lin, Hong; Jiang, Ruo-Dan; Dong, Li-Min; Huang, Lin; Zheng, Gang

2018-06-01

This study assessed the potential of porous zirconia ceramic as an alternative to dentin via an in vitro dentin barrier cytotoxicity test. The permeability of dentin and porous zirconia ceramic was measured using a hydraulic-conductance system, and their permeability was divided into two groups: high and low. Using an in vitro dentin barrier test, the cytotoxicity of dental materials by dentin and porous zirconia ceramic was compared within the same permeability group. The L-929 cell viability was assessed by MTT assay. The mean (SD) permeability of the high and low group for dentin was 0.334 (0.0873) and 0.147 (0.0377) μl min -1  cm -2  cm H 2 O -1 and for zirconia porous ceramic was 0.336 (0.0609) and 0.146 (0.0340) μl min -1  cm -2  cm H 2 O -1 . The cell viability of experimental groups which are the low permeability group was higher than that of the high permeability group for both dentin and porous zirconia ceramic as a barrier except for Maxcem Elite ™ by porous zirconia ceramic. There was no significant difference between dentin and porous zirconia ceramic in cell viability, within either the high or low permeability group for all materials. The SD for cell viability of the porous zirconia ceramic was less than that of the dentin, across all materials within each permeability group, except for Maxcem Elite ™ in the high permeability group. Porous zirconia ceramic, having similar permeability to dentin at the same thickness, can be used as an alternative to dentin for in vitro dentin barrier cytotoxicity tests. In vitro dentin barrier cytotoxicity tests when a standardized porous zirconia ceramic was used as a barrier could be useful for assessing the potential toxicity of new dental materials applied to dentin before applying in clinical and may resolve the issue of procuring human teeth when testing proceeds.

Effects of blood contamination on microtensile bond strength to dentin of three self-etch adhesives.

PubMed

Chang, Seok Woo; Cho, Byeong Hoon; Lim, Ran Yeob; Kyung, Seung Hyun; Park, Dong Sung; Oh, Tae Seok; Yoo, Hyun Mi

2010-01-01

This study evaluated the effects of blood contamination and decontamination methods during different steps of bonding procedures on the microtensile bond strength of two-step self-etch adhesives to dentin. Sixty extracted human molars were ground flat to expose occlusal dentin. The 60 molars were randomly assigned to three groups, each treated with a different two-step self-etch adhesive: Clearfil SE Bond, AdheSE and Tyrian SPE. In turn, these groups were subdivided into five subgroups (n = 20), each treated using different experimental conditions as follows: control group-no contamination; contamination group 1-CG1: primer application/ contamination/primer re-application; contamination group 2-CG2: primer application/contamination/wash/dry/primer re-application; contamination group 3-CG3: primer application/adhesive application/light curing/contamination/ adhesive re-application/light curing; contamina- tion group 4-CG4: primer application/adhesive application/light curing/contamination/wash/ dry/adhesive re-application/light curing. Composite buildup was performed using Z250. After 24 hours of storage in distilled water at 37 degrees C, the bonded specimens were trimmed to an hourglass shape and serially sectioned into slabs with 0.6 mm2 cross-sectional areas. Microtensile bond strengths (MTBS) were assessed for each specimen using a universal testing machine. The data were analyzed by two-way ANOVA followed by a post hoc LSD test. SEM evaluations of the fracture modes were also performed. The contaminated specimens showed lower bond strengths than specimens in the control group (p < 0.05), with the exception of CG1 in the Clearfil SE group and CG2 and CG3 in the Tyrian SPE group. Among the three self-etch adhesives, the Tyrian SPE group exhibited a significantly lower average MTBS compared to the Clearfil SE Bond and AdheSE (p < 0.05) groups. Based on the results of the current study, it was found that blood contamination reduced the MTBS of all three self-etch adhesives to dentin, and water-rinsing was unable to overcome the effects of blood contamination.

Analysis of Resin-Dentin Interface Morphology and Bond Strength Evaluation of Core Materials for One Stage Post-Endodontic Restorations

PubMed Central

Bitter, Kerstin; Gläser, Christin; Neumann, Konrad; Blunck, Uwe; Frankenberger, Roland

2014-01-01

Purpose Restoration of endodontically treated teeth using fiber posts in a one-stage procedure gains more popularity and aims to create a secondary monoblock. Data of detailed analyses of so called “post-and-core-systems” with respect to morphological characteristics of the resin-dentin interface in combination with bond strength measurements of fiber posts luted with these materials are scarce. The present study aimed to analyze four different post-and-core-systems with two different adhesive approaches (self-etch and etch-and-rinse). Materials and Methods Human anterior teeth (n = 80) were endodontically treated and post space preparations and post placement were performed using the following systems: Rebilda Post/Rebilda DC/Futurabond DC (Voco) (RB), Luxapost/Luxacore Z/Luxabond Prebond and Luxabond A+B (DMG) (LC), X Post/Core X Flow/XP Bond and Self Cure Activator (Dentsply DeTrey) (CX), FRC Postec/MultiCore Flow/AdheSE DC (Ivoclar Vivadent) (MC). Adhesive systems and core materials of 10 specimens per group were labeled using fluorescent dyes and resin-dentin interfaces were analyzed using Confocal Laser Scanning Microscopy (CLSM). Bond strengths were evaluated using a push-out test. Data were analyzed using repeated measurement ANOVA and following post-hoc test. Results CLSM analyses revealed significant differences between groups with respect to the factors hybrid layer thickness (p<0.0005) and number of resin tags (p = 0.02; ANOVA). Bond strength was significantly affected by core material (p = 0.001), location inside the root canal (p<0.0005) and incorporation of fluorescent dyes (p = 0.036; ANOVA). CX [7.7 (4.4) MPa] demonstrated significantly lower bond strength compared to LC [14.2 (8.7) MPa] and RB [13.3 (3.7) MPa] (p<0.05; Tukey HSD) but did not differ significantly from MC [11.5 (3.5) MPa]. Conclusion It can be concluded that bond strengths inside the root canal were not affected by the adhesive approach of the post-and-core-system. All systems demonstrated homogenous hybrid layer formation and penetration into the dentinal tubules in spite of the complicating conditions for adhesion inside the root canal. PMID:24586248

Dentinal permeation modeling

NASA Astrophysics Data System (ADS)

Trunina, Natalia; Derbov, Vladimir; Tuchin, Valery; Altshuler, Gregory

2008-06-01

Dentinal permeation is of interest in a wide context of tooth care and treatment, in particular, tooth color improvement using combination of chemical whitening agents and light activation. A simple model of dentinal permeation accounting for the morphology of human tooth dentine and including dentinal tubules, more dense and homogeneous peritubular dentine, and less dense and less homogeneous intertubular dentin is proposed. Calculation of permeability of dentine layer is carried out for H IIO and H IIO II versus the tubule diameter and tubule density taken from the microphotograph analysis. This opens the possibility to calculate the distribution of permeability over the tooth surface taking into account the variations of tubule diameter and density as well as those of the diffusion coefficients and layer thickness

Micro-shear bond strengths of adhesive resins to coronal dentin versus the floor of the pulp chamber.

PubMed

Toba, Shigemitsu; Veerapravati, Weeraporn; Shimada, Yasushi; Nikaido, Toru; Tagami, Junji

2003-09-01

To evaluate the micro-shear bond strengths to superficial coronal dentin and the floor of the pulp chamber using two dentin bonding systems and to compare the ultrastructure of the resin-dentin interface of the two regions. 30 non-carious molars were used to obtain 2 mm thick slabs of coronal dentin and dentin at the pulp chamber. The specimens in each region were divided into three sub-groups to be bonded as follows; Clearfil SE Bond was used according to the manufacturer's instructions, Single Bond was applied to either wet dentin (Blot dry Group) or air-dried dentin (Dry Group) after phosphoric acid etching. A resin composite cylinder 0.5 mm high and 0.75 mm in diameter formed using a vinyl tube was bonded to the dentin. Specimens were stored at 37 degrees C for 24 hours in water and then stressed in shear at a crosshead speed of 1 mm/minute. The data were analyzed with one-way ANOVA and Fisher's PLSD test at the 5% level of significance. In addition, the ultrastructure of cross-sectioned dentin surfaces, the conditioned dentin surface and the resin dentin interfaces were observed by SEM. The bond strengths of Clearfil SE Bond and the Single Bond Blot dry group were approximately 40 MPa in coronal dentin and 30 MPa in the dentin at the floor of the pulp chamber respectively. However, the bond strengths of Single Bond were significantly lower in the Dry condition (MPa) (P < 0.05). SEM observations revealed the thickness of the hybrid layer created by Clearfil SE Bond in coronal dentin and at the floor of the pulp chamber were less than 1.0 microm thick. For Single Bond, a 3-4 microm hybrid layer was created in coronal dentin, while a thinner hybrid layer was observed in the floor of the pulp chamber. Morphological and structural variations in dentin may have influenced the bond strengths of the bonding systems to the floor of the pulp chamber.

Long-term stability of dentin matrix following treatment with various natural collagen cross-linkers

PubMed Central

Castellan, Carina Strano; Bedran-Russo, Ana Karina; Karol, Sachin; Rodrigues Pereira, Patrícia Nóbrega

2011-01-01

Objectives Collagen disorganization is one of the main degradation patterns found in unsuccessful adhesive restorations. The hypothesis of this study was that pretreatment using natural collagen cross-linking agents rich in proanthocyanidin (PA) would improve mechanical properties and stability over time of the dentin collagen and, thus, confer a more resistant and lasting substrate for adhesive restorations. Methods PA-based extracts, from grape seed (GSE), cocoa seed (CSE), cranberry (CRE), cinnamon (CNE) and açaí berry (ACE) were applied over the demineralized dentin. The apparent elastic modulus (E) of the treated dentin collagen was analyzed over a 12 months period. Specimens were immersed in the respective solution and E values were obtained by a micro-flexural test at baseline, 10, 30, 60, 120 and 240 min. Samples were stored in artificial saliva and re-tested after 3, 6 and 12 months. Data was analyzed using ANOVA and Tukey test. Results GSE and CSE extracts showed a time-dependant effect and were able to improve [240 min (MPa): GSE=108.96±56.08; CSE=59.21±24.87] and stabilize the E of the organic matrix [12 months (MPa): GSE=40.91±19.69; CSE= 42.11±13.46]. CRE and CNE extracts were able to maintain the E of collagen matrices constant over 12 months [CRE=11.17±7.22; CNE= 9,96±6.11; MPa]. ACE (2.64±1.22 MPa) and control groups immersed in neat distilled water (1.37±0.69 MPa) and ethanol water (0.95±0.33MPa) showed no effect over dentin organic matrix and enable their degradation and reduction of mechanical properties. Significance Some PA-based extracts were capable of improving and stabilizing collagen matrices through exogenous cross-links induction. PMID:21783144

Hypersensitivity reactions associated with L-asparaginase administration in 142 dogs and 68 cats with lymphoid malignancies: 2007-2012.

PubMed

Blake, Mary Kay; Carr, Brittany J; Mauldin, Glenna E

2016-02-01

Clinically significant hypersensitivity reactions (HSRs) to the chemotherapy drug L-asparaginase are reported in humans and dogs, but frequency in small animals is not well-defined. This study retrospectively evaluated the frequency of HSR to L-asparaginase given by IM injection to dogs and cats with lymphoid malignancies. The medical records of all dogs and cats treated with at least 1 dose of L-asparaginase chemotherapy over a 5-year period were reviewed. A total of 370 doses of L-asparaginase were administered to the dogs, with 88 of 142 dogs receiving multiple doses, and 6 dogs experiencing an HSR. A total of 197 doses were administered to the cats, with 33 of 68 cats receiving multiple doses, and no cats experiencing an HSR. Hypersensitivity reactions were documented in 4.2% of dogs, and in association with 1.6% of L-asparaginase doses administered. These results show that HSRs occur uncommonly among dogs and cats, even with repeated dosing.

Hypersensitivity reactions associated with L-asparaginase administration in 142 dogs and 68 cats with lymphoid malignancies: 2007–2012

PubMed Central

Blake, Mary Kay; Carr, Brittany J.; Mauldin, Glenna E.

2016-01-01

Clinically significant hypersensitivity reactions (HSRs) to the chemotherapy drug L-asparaginase are reported in humans and dogs, but frequency in small animals is not well-defined. This study retrospectively evaluated the frequency of HSR to L-asparaginase given by IM injection to dogs and cats with lymphoid malignancies. The medical records of all dogs and cats treated with at least 1 dose of L-asparaginase chemotherapy over a 5-year period were reviewed. A total of 370 doses of L-asparaginase were administered to the dogs, with 88 of 142 dogs receiving multiple doses, and 6 dogs experiencing an HSR. A total of 197 doses were administered to the cats, with 33 of 68 cats receiving multiple doses, and no cats experiencing an HSR. Hypersensitivity reactions were documented in 4.2% of dogs, and in association with 1.6% of L-asparaginase doses administered. These results show that HSRs occur uncommonly among dogs and cats, even with repeated dosing. PMID:26834270

Hypersensitivity reaction to mizolastine: study of cross reactions.

PubMed

Gonzalo-Garijo, M A; Jiménez-Ferrera, G; Bobadilla-González, P; Cordobés-Durán, C

2006-01-01

A 26-year-old male suffering from acute rhinitis took the first dose of Zolistan (mizolastine, 10 mg), orally, and 15 minutes later he developed intense generalized pruritus, cutaneous rash, oropharyngeal pruritus, edema on his face, difficulty in swallowing, and mild dyspnea. He was treated with methylprednisolone and epinephrine and improved within 30 minutes. The patient had not taken mizolastine before and he has avoided it since the reaction. Cutaneous tests with Zolistan and its excipients proved negative. Simple-blind oral challenge tests with the excipients and then with Zolistan were positive only with Zolistan. In order to confirm the absence of cross-reactivity between mizolastine and other benzimidazoles, we tested omeprazole, domperidone and mebendazole, all of which yielded negative results. To our knowledge, this is the second case of immediate hypersensitivity to mizolastine documented to date. In our case, the clinical history, physical examination and provocation tests allow us to establish the diagnosis of hypersensitivity to mizolastine and exclude the cross reactivity with other benzimidazole derivatives.

Patch Testing for Evaluation of Hypersensitivity to Implanted Metal Devices: A Perspective From the American Contact Dermatitis Society.

PubMed

Schalock, Peter C; Crawford, Glen; Nedorost, Susan; Scheinman, Pamela L; Atwater, Amber Reck; Mowad, Christen; Brod, Bruce; Ehrlich, Alison; Watsky, Kalman L; Sasseville, Denis; Silvestri, Dianne; Worobec, Sophie M; Elliott, John F; Honari, Golara; Powell, Douglas L; Taylor, James; DeKoven, Joel

2016-01-01

The American Contact Dermatitis Society recognizes the interest in the evaluation and management of metal hypersensitivity reactions. Given the paucity of robust evidence with which to guide our practices, we provide reasonable evidence and expert opinion-based guidelines for clinicians with regard to metal hypersensitivity reaction testing and patient management. Routine preoperative evaluation in individuals with no history of adverse cutaneous reactions to metals or history of previous implant-related adverse events is not necessary. Patients with a clear self-reported history of metal reactions should be evaluated by patch testing before device implant. Patch testing is only 1 element in the assessment of causation in those with postimplantation morbidity. Metal exposure from the implanted device can cause sensitization, but a positive metal test does not prove symptom causality. The decision to replace an implanted device must include an assessment of all clinical factors and a thorough risk-benefit analysis by the treating physician(s) and patient.

Mechanical properties and molecular structure analysis of subsurface dentin after Er:YAG laser irradiation.

PubMed

He, Zhengdi; Chen, Lingling; Hu, Xuejuan; Shimada, Yasushi; Otsuki, Masayuki; Tagami, Junji; Ruan, Shuangchen

2017-10-01

The purpose of this study was to evaluate the chemical and mechanical modifications in subsurface dentin layer after Er: YAG (Erbium-Yttrium Aluminium Garnet) laser irradiation, as the guidance of new dental restorative materials specific for laser irradiated dentin. Dentin disks obtained from extracted human molars were prepared and exposed to a single pulse Er:YAG laser irradiation at 80mJ/pulse. After laser irradiation the mechanical and chemical characteristics of intertubular dentin in subsurface layer were studied using nanoindentation tester and micro-Raman spectromy (μ-RS). The dentin 5-50µm depth beneath the lased surface was determined as testing area. Two-way analysis of variance (ANOVA) were used to compare the mechanical values between lased and untreated subsurface dentin (P = 0.05). A laser affected subsurface dentin layer after Er:YAG laser treatment is present. The laser irradiation is considered to decrease the mechanical properties in the superficial subsurface layer (<15µm deep). There was no significant difference in nanohardness and Young's modulus between lased subsurface dentin and untreated dentin (p > 0.05) under the depth of 15µm. However, the dentin at 5µm and 10µm depth beneath the lased surface exhibited significantly lower (~ 47.8% and ~ 33.6% respectively) hardness (p < 0.05). Er:YAG laser irradiation affected both mineral and organic components in subsurface dentin layer, a higher degree of crystallinity and reduced organic compounds occurred in the lased subsurface dentin. Under the tested laser parameters, Er:YAG laser irradiation causes lower mechanical values and reduction of organic components in subsurface dentin, which has deleterious effects on resin adhesion to this area. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

The influence of the energy density and other clinical parameters on bond strength of Er:YAG-conditioned dentin compared to conventional dentin adhesion.

PubMed

Gisler, Gottfried; Gutknecht, Norbert

2014-01-01

The aim of this in vitro study was to optimise clinical parameters and the energy density of Er:YAG laser-conditioned dentin for class V fillings. Shear tests in three test series were conducted with 24 freshly extracted human third molars as samples for each series. For every sample, two orofacial and two approximal dentin surfaces were prepared. The study design included different laser energies, a thin vs a thick bond layer, the influence of adhesives as well as one-time- vs two-time treatment. The best results with Er:YAG-conditioned dentin were obtained with fluences just above the ablation threshold (5.3 J/cm(2)) in combination with a self-etch adhesive, a thin bond layer and when bond and composite were two-time cured. Dentin conditioned this way reached an averaged bond strength of 23.32 MPa (SD 5.3) and 24.37 MPa (SD 6.06) for two independent test surfaces while showing no statistical significance to conventional dentin adhesion and two-time treatment with averaged bond strength of 24.93 MPa (SD 11.51). Significant reduction of bond strength with Er:YAG-conditioned dentin was obtained when using either a thick bond layer, twice the laser energy (fluence 10.6 J/cm(2)) or with no dentin adhesive. The discussion showed clearly that in altered (sclerotic) dentin, e.g. for class V fillings of elderly patients, bond strengths in conventional dentin adhesion are constantly reduced due to the change of the responsibles, bond giving dentin structures, whereas for Er:YAG-conditioned dentin, the only way to get an optimal microretentive bond pattern is a laser fluence just above the ablation threshold of sclerotic dentin.

The effect of Er:YAG laser irradiation on the bond stability of self-etch adhesives at different dentin depths.

PubMed

Karadas, Muhammet; Çağlar, İpek

2017-07-01

The aim of this study was to evaluate the effect of Er:YAG laser irradiation on the micro-shear bond strength of self-etch adhesives to the superficial dentin and the deep dentin before and after thermocycling. Superficial dentin and deep dentin surfaces were prepared by flattening of the occlusal surfaces of extracted human third molars. The deep or superficial dentin specimens were randomized into three groups according to the following surface treatments: group I (control group), group II (Er:YAG laser; 1.2 W), and group III (Er:YAG laser; 0.5 W). Clearfil SE Bond or Clearfil S 3 Bond was applied to each group's dentin surfaces. After construction of the composite blocks on the dentin surface, the micro-shear bond testing of each adhesive was performed at 24 h or after 15,000 thermal cycles. The data were analyzed using a univariate analysis of variance and Tukey's test (p < 0.05). Laser irradiation in superficial dentin did not significantly affect bond strength after thermocycling (p > 0.05). However, deep-dentin specimens irradiated with laser showed significantly higher bond strengths than did control specimens after thermocycling (p < 0.05). Thermocycling led to significant deterioration in the bond strengths of all deep-dentin groups. The stable bond strength after thermocycling was measured for all of the superficial-dentin groups. No significant difference was found between the 0.5 and 1.2 W output power settings. In conclusion, the effect of laser irradiation on the bond strength of self-etch adhesives may be altered by the dentin depth. Regardless of the applied surface treatment, deep dentin showed significant bond degradation.

Morphology and chemical composition of dentin in permanent first molars with the diagnose MIH.

PubMed

Heijs, Suzanne C B; Dietz, Wolfram; Norén, Jörgen G; Blanksma, Nynke G; Jälevik, Birgitta

2007-01-01

The purpose of this investigation was to study the morphology and distribution of some inorganic elements in dentin in first permanent molars from children with Molar-Incisor Hypomineralization (MIH). Sixty four tooth sections from thirty two children were examined in polarized light. Fifteen representative sections were selected for SEM/XRMA analysis; 5 were used for SEM analysis and 10 for XRMA analysis. No morphological changes in the dentin were revealed in polarized light microscopy (PLM). However, in all but two sections interglobular dentin was found. The SEM analyzes confirmed the findings of the PLM with no structural changes to be found in the dentin. The XRMA results showed a difference in the concentration of elements between dentin below normal and dentin below carious or hypomineralized enamel. Elements related to organic matter appeared with higher values in dentin below hypomineralized and carious enamel. The morphological and chemical findings in dentin below hypomineralized enamel imply that the odontoblasts are not affected in cases of MIH, but may be affected by hypocalcemia, reflected by the presence of interglobular dentin.

A review of heat transfer in human tooth--experimental characterization and mathematical modeling.

PubMed

Lin, Min; Xu, Feng; Lu, Tian Jian; Bai, Bo Feng

2010-06-01

With rapid advances in modern dentistry, high-energy output instruments (e.g., dental lasers and light polymerizing units) are increasingly employed in dental surgery for applications such as laser assisted tooth ablation, bleaching, hypersensitivity treatment and polymerization of dental restorative materials. Extreme high temperature occurs within the tooth during these treatments, which may induce tooth thermal pain (TTP) sensation. Despite the wide application of these dental treatments, the underlying mechanisms are far from clear. Therefore, there is an urgent need to better understand heat transfer (HT) process in tooth, thermally induced damage of tooth, and the corresponding TTP. This will enhance the design and optimization of clinical treatment strategies. This paper presents the state-of-the-art of the current understanding on HT in tooth, with both experimental study and mathematical modeling reviewed. Limitations of the current experimental and mathematical methodologies are discussed and potential solutions are suggested. Interpretation of TTP in terms of thermally stimulated dentinal fluid flow is also discussed. Copyright (c) 2010 Academy of Dental Materials. All rights reserved.

Asthma, hypersensitivity pneumonitis and other respiratory diseases caused by metalworking fluids.

PubMed

Rosenman, Kenneth D

2009-04-01

To highlight advances in understanding the respiratory disease associated with metal machining, a common work process involving approximately 1.2 million workers in the USA. Recent studies emphasize that work-related asthma and hypersensitivity pneumonitis continue to be caused by exposure to metalworking fluid. Identification of an individual patient indicates the need for follow-up investigations at the work site to prevent additional disease and/or identify additional effected individuals. Identification of the causal agent for hypersensitivity pneumonitis has centered on microbial contamination of metalworking fluids with a number of studies focusing on Mycobacterium immunogenum. Both asthma and hypersensitivity pneumonitis occur among workers exposed to metalworking fluid. The incidence of these diseases among such workers is unknown. Outbreaks of these conditions continue to be identified among metal machinists. Whether these are true outbreaks associated with some breakdown in workplace controls or, rather the recognition of ongoing endemic disease that is typically misdiagnosed as pneumonia or common adult onset asthma, needs further evaluation. Further work to elucidate the specific causal agent(s) is necessary to affect effective workplace controls. Treating an identified individual case as an index case with a follow-up workplace investigation will only be possible if practicing physicians interact with public health authorities to report newly diagnosed cases.

Biomimetic remineralization of dentin

PubMed Central

Niu, Li-na; Zhang, Wei; Pashley, David H.; Breschi, Lorenzo; Mao, Jing; Chen, Ji-hua; Tay, Franklin R.

2013-01-01

Objectives Remineralization of demineralized dentin is important for improving dentin bonding stability and controlling primary and secondary caries. Nevertheless, conventional dentin remineralization strategy is not suitable for remineralizing completely-demineralized dentin within hybrid layers created by etch-and-rinse and moderately aggressive self-etch adhesive systems, or the superficial part of a caries-affected dentin lesion left behind after minimally invasive caries removal. Biomimetic remineralization represents a different approach to this problem by attempting to backfill the demineralized dentin collagen with liquid-like amorphous calcium phosphate nanoprecursor particles that are stabilized by biomimetic analogs of noncollagenous proteins. Methods This paper reviewed the changing concepts in calcium phosphate mineralization of fibrillar collagen, including the recently discovered, non-classical particle-based crystallization concept, formation of polymer-induced liquid- precursors (PILP), experimental collagen models for mineralization, and the need for using phosphate-containing biomimetic analogs for biomimetic mineralization of collagen. Published work on the remineralization of resin-dentin bonds and artificial caries-like lesions by various research groups was then reviewed. Finally, the problems and progress associated with the translation of a scientifically-sound concept into a clinically-applicable approach are discussed. Results and Significance The particle-based biomimetic remineralization strategy based on the PILP process demonstrates great potential in remineralizing faulty hybrid layers or caries-like dentin. Based on this concept, research in the development of more clinically feasible dentin remineralization strategy, such as incorporating poly(anionic) acid-stabilized amorphous calcium phosphate nanoprecursor-containing mesoporous silica nanofillers in dentin adhesives, may provide a promising strategy for increasing of the durability of resin-dentin bonding and remineralizing caries-affected dentin. PMID:23927881

Influence of laboratory degradation methods and bonding application parameters on microTBS of self-etch adhesives to dentin.

PubMed

Erhardt, Maria Carolina G; Pisani-Proença, Jatyr; Osorio, Estrella; Aguilera, Fátima S; Toledano, Manuel; Osorio, Raquel

2011-04-01

To evaluate the laboratory resistance to degradation and the use of different bonding treatments on resin-dentin bonds formed with three self-etching adhesive systems. Flat, mid-coronal dentin surfaces from extracted human molars were bonded according to manufacturer's directions and submitted to two challenging regimens: (A) chemical degradation with 10% NaOC1 immersion for 5 hours; and (B) fatigue loading at 90 N using 50,000 cycles at 3.0 Hz. Additional dentin surfaces were bonded following four different bonding application protocols: (1) according to manufacturer's directions; (2) acid-etched with 36% phosphoric acid (H3PO4) for 15 seconds; (3) 10% sodium hypochlorite (NaOClaq) treated for 2 minutes, after H3PO4-etching; and (4) doubling the application time of the adhesives. Two one-step self-etch adhesives (an acetone-based: Futurabond/FUT and an ethanol-based: Futurabond NR/FNR) and a two-step self-etch primer system (Clearfil SE Bond/CSE) were examined. Specimens were sectioned into beams and tested for microtensile bond strength (microTBS). Selected debonded specimens were observed under scanning electron microscopy (SEM). Data (MPa) were analyzed by ANOVA and multiple comparisons tests (alpha= 0.05). microTBS significantly decreased after chemical and mechanical challenges (P< 0.05). CSE showed higher microTBS than the other adhesive systems, regardless the bonding protocol. FUT attained the highest microTBS after doubling the application time. H3PO4 and H3PO4 + NaOCl pretreatments significantly decreased bonding efficacy of the adhesives.

Bonding of fibre-reinforced composite post to root canal dentin.

PubMed

Bell, Anna-Maria Le; Lassila, Lippo V J; Kangasniemi, Ilkka; Vallittu, Pekka K

2005-08-01

The aim of this study was to determine bonding properties of two types of fibre-reinforced composite (FRC) posts cemented into root canals of molars. Serrated titanium posts served as reference. Prefabricated carbon/graphite FRC posts with cross-linked polymer matrix and individually formed glass FRC posts with interpenetrating polymer network (IPN) polymer matrix were compared. The crowns of extracted third molars were removed and post space (diameter: 1.5mm) was drilled, etched and bonded. The posts were treated with dimethacrylate adhesive resin, light-polymerized and cemented with a dual-polymerizing composite resin luting cement. After thermocycling (6000x) the samples were cut into discs of thicknesses: 1, 2 and 4mm (n=12/group). Push-out force was measured by pushing the post from one end. Assessment of failure mode was made under a stereomicroscope (1, adhesive failure between post and cement; 2, cohesive failure of post-system; 3, adhesive failure between cement and dentin). The push-out force increased with increased height of dentin disc in all groups (ANOVA, p<0.001). In the 4mm thick dentin discs the individually formed glass FRC posts showed highest push-out force and the difference to that of the titanium posts was significant (ANOVA, p<0.001). The other differences were not statistically significant. None of the individually formed glass FRC posts showed adhesive failures between the post and the cement. Contrary to the other posts, there were no adhesive (post-cement) failures with the individually formed glass FRC posts, suggesting better interfacial adhesion of cement to these posts.

Davallialactone reduces inflammation and repairs dentinogenesis on glucose oxidase-induced stress in dental pulp cells.

PubMed

Lee, Young-Hee; Kim, Go-Eun; Song, Yong-Beom; Paudel, Usha; Lee, Nan-Hee; Yun, Bong-Sik; Yu, Mi-Kyung; Yi, Ho-Keun

2013-11-01

The chronic nature of diabetes mellitus (DM) raises the risk of oral complication diseases. In general, DM causes oxidative stress to organs. This study aimed to evaluate the cellular change of dental pulp cells against glucose oxidative stress by glucose oxidase with a high glucose state. The purpose of this study was to test the antioxidant character of davallialactone and to reduce the pathogenesis of dental pulp cells against glucose oxidative stress. The glucose oxidase with a high glucose concentration was tested for hydroxy peroxide (H2O2) production, cellular toxicity, reactive oxygen species (ROS) formation, induction of inflammatory molecules and disturbance of dentin mineralization in human dental pulp cells. The anti-oxidant effect of Davallilactone was investigated to restore dental pulp cells' vitality and dentin mineralization via reduction of H2O2 production, cellular toxicity, ROS formation and inflammatory molecules. The treatment of glucose oxidase with a high glucose concentration increased H2O2 production, cellular toxicity, and inflammatory molecules and disturbed dentin mineralization by reducing pulp cell activity. However, davallialactone reduced H2O2 production, cellular toxicity, ROS formation, inflammatory molecules, and dentin mineralization disturbances even with a long-term glucose oxidative stress state. The results of this study imply that the development of oral complications is related to the irreversible damage of dental pulp cells by DM-induced oxidative stress. Davallialactone, a natural antioxidant, may be useful to treat complicated oral disease, representing an improvement for pulp vital therapy. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

A profilometry-based dentifrice abrasion Method for V8 brushing machines. Part I: Introduction to RDA-PE.

PubMed

White, Donald J; Schneiderman, Eva; Colón, Ellen; St John, Samuel

2015-01-01

This paper describes the development and standardization of a profilometry-based method for assessment of dentifrice abrasivity called Radioactive Dentin Abrasivity - Profilometry Equivalent (RDA-PE). Human dentine substrates are mounted in acrylic blocks of precise standardized dimensions, permitting mounting and brushing in V8 brushing machines. Dentin blocks are masked to create an area of "contact brushing." Brushing is carried out in V8 brushing machines and dentifrices are tested as slurries. An abrasive standard is prepared by diluting the ISO 11609 abrasivity reference calcium pyrophosphate abrasive into carboxymethyl cellulose/glycerin, just as in the RDA method. Following brushing, masked areas are removed and profilometric analysis is carried out on treated specimens. Assessments of average abrasion depth (contact or optical profilometry) are made. Inclusion of standard calcium pyrophosphate abrasive permits a direct RDA equivalent assessment of abrasion, which is characterized with profilometry as Depth test/Depth control x 100. Within the test, the maximum abrasivity standard of 250 can be created in situ simply by including a treatment group of standard abrasive with 2.5x number of brushing strokes. RDA-PE is enabled in large part by the availability of easy-to-use and well-standardized modern profilometers, but its use in V8 brushing machines is enabled by the unique specific conditions described herein. RDA-PE permits the evaluation of dentifrice abrasivity to dentin without the requirement of irradiated teeth and infrastructure for handling them. In direct comparisons, the RDA-PE method provides dentifrice abrasivity assessments comparable to the gold industry standard RDA technique.

Photodynamic therapy for inactivating endodontic bacterial biofilms and effect of tissue inhibitors on antibacterial efficacy

NASA Astrophysics Data System (ADS)

Shrestha, Annie; Kishen, Anil

Complex nature of bacterial cell membrane and structure of biofilm has challenged the efficacy of antimicrobial photodynamic therapy (APDT) to achieve effective disinfection of infected root canals. In addition, tissue-inhibitors present inside the root canals are known to affect APDT activity. This study was aimed to assess the effect of APDT on bacterial biofilms and evaluate the effect of tissue-inhibitors on the APDT. Rose-bengal (RB) and methylene-blue (MB) were tested on Enterococcus faecalis (gram-positive) and Pseudomonas aeruginosa (gram-negative) biofilms. In vitro 7- day old biofilms were sensitized with RB and MB, and photodynamically activated with 20-60 J/cm2. Photosensitizers were pre-treated with different tissue-inhibitors (dentin, dentin-matrix, pulp tissue, bacterial lipopolysaccharides (LPS), and bovine serum albumin (BSA)) and tested for antibacterial effect of APDT. Microbiological culture based analysis was used to analyze the cell viability, while Laser Scanning Confocal Microscopy (LSCM) was used to examine the structure of biofilm. Photoactivation resulted in significant reduction of bacterial biofilms with RB and MB. The structure of biofilm under LSCM was found to be disrupted with reduced biofilm thickness. Complete biofilm elimination could not be achieved with both tested photosensitizers. APDT effect using MB and RB was inhibited in a decreasing order by dentin-matrix, BSA, pulp, dentin and LPS (P< 0.05). Both strains of bacterial biofilms resisted complete elimination after APDT and the tissue inhibitors existing within the root canal reduced the antibacterial activity at varying degrees. Further research is required to enhance the antibacterial efficacy of APDT in an endodontic environment.

Can 1% chlorhexidine diacetate and ethanol stabilize resin-dentin bonds?

PubMed Central

Manso, Adriana Pigozzo; Grande, Rosa Helena Miranda; Bedran-Russo, Ana Karina; Reis, Alessandra; Loguercio, Alessandro D.; Pashley, David Henry; Carvalho, Ricardo Marins

2014-01-01

Objectives To examine the effects of the combined use of chlorhexidine and ethanol on the durability of resin-dentin bonds. Methods Forty-eight flat dentin surfaces were etched (32% phosphoric acid), rinsed (15 s) and kept wet until bonding procedures. Dentin surfaces were blot-dried with absorbent paper and re-wetted with water (Water, control), 1% chlorhexidine diacetate in water (CHD/Water), 100% ethanol (Ethanol), or 1% chlorhexidine diacetate in ethanol (CHD/Ethanol) solutions for 30 s. They were then bonded with All Bond 3 (AB3, Bisco) or Excite (EX, Ivoclar-Vivadent) using a smooth, continuous rubbing application (10 s), followed by 15 s gentle air stream to evaporate solvents. The adhesives were light-cured (20 s) and resin composite build-ups constructed for the microtensile method. Bonded beams were obtained and tested after 24-hours, 6-months and 15-months of water storage at 37°C. Storage water was changed every month. Effects of treatment and testing periods were analyzed (ANOVA, Holm-Sidak, p<0.05) for each adhesive. Results There were no interactions between factors for both etch-and-rinse adhesives. AB3 was significantly affected only by storage (p = 0.003). Excite was significantly affected only by treatments (p = 0.048). AB3 treated either with ethanol or CHD/ethanol resulted in reduced bond strengths after 15 months. The use of CHD/ethanol resulted in higher bond strengths values for Excite. Conclusions Combined use of ethanol/1% chlorhexidine diacetate did not stabilize bond strengths after 15 months. PMID:24815823

Tannic acid for smear layer removal: pilot study with scanning electron microscope.

PubMed

Bitter, N C

1989-04-01

The effects of a 25% tannic acid solution applied to the surface of prepared dentin was compared with untreated prepared dentin surfaces. The following results were demonstrated by electron microscope observation: (1) cavity preparations created an amorphous dentinal smear layer, (2) placement of a 25% tannic acid solution for 15 seconds removed the smear layer, (3) the contents of the dentinal tubules were not removed and no enlargement of dentinal tubules was found, and (3) a clean dentinal surface was observed.

Presence of matrix vesicles in the body of odontoblasts and in the inner third of dentinal tissue: a scanning electron microscopic study.

PubMed

Garcés-Ortíz, Maricela; Ledesma-Montes, Constantino; Reyes-Gasga, José

2013-05-01

The aim of this report is to present the results of a scanning electron microscopic study on the presence of matrix vesicles (MVs) found in human dentine. Dentin tissue from 20 human bicuspids was analyzed by means of scanning electron microscopy. MVs were found as outgrowths of the cellular membrane of the odontoblastic body, the more proximal portion of the odontoblastic process before entering the dentinal tubule and in the odontoblastic process within the inner third of the dentin. Size of MVs varied depending on location. In the inner third of dentin, they were seen in diverse positions; as membranal outgrowths, deriving from the odontoblastic process, lying free in the intratubular space and attached to the dentinal wall. Sometimes, they were seen organized forming groups of different sizes and shapes or as multivesicular chains running from the surface of the odontoblastic process to the tubular wall. MVs were present in places never considered: 1) the body of odontoblasts; 2) the most proximal part of the odontoblastic processes before entering the circumpulpal dentine and also: 3) in the inner third of dentinal tissue. According to our results, MVs not only participate during mantle dentin mineralization during early dentinogenesis, they also contribute during the mineralization process of the inner dentin.

The effect of MTA application on the affected dentine remineralization after partial caries excavation (in vivo)

NASA Astrophysics Data System (ADS)

Pratiwi, A. R.; Meidyawati, R.; Djauharie, N.

2017-08-01

On deep carious lesions, only thin dentine remains, causing a high risk of pulp exposure during the removal of all infected dentine. A minimally invasive technique is required, such as a partial caries excavation method in the infected dentine tissue and the use of bioactive material that can promote (Mineral Trioxide Aggregate) MTA remineralization. To compare the remineralization of deep carious lesion-affected dentine with the removal of some and all the infected dentine after the application of MTA. Subjects were divided into two groups: group I had only some parts of the infected dentine removed before MTA application, while group II had all the infected dentine removed before MTA application. Each group was measured on the pixel grey value before the treatment and again four weeks after the MTA application, and then the results were compared. Furthermore, the enhancement of both groups’ grey values were compared. Remineralization occurred in both groups after the MTA application. There was no significant difference in the remineralization level of the affected dentine in both groups I and II four weeks after the MTA application. Remineralization occurred in the affected dentine in both groups, either by removing only some parts or all the infected dentine in the deep carious lesion.

Characteristics of adverse drug reactions in a vemurafenib early post-marketing phase vigilance study in Japan.

PubMed

Uhara, H; Kiyohara, Y; Tsuda, A; Takata, M; Yamazaki, N

2018-02-01

Post-approval research or monitoring is important to determine real-world safety of new products; however, evidence is scant for vemurafenib in Japanese patients. In Japan, a unique system is officially obligated to investigate post-approval safety. Here we report the first adverse drug reaction (ADR) data from vemurafenib-treated Japanese patients with metastatic melanoma. Data were collected in an early post-marketing phase vigilance (EPPV) study. ADRs were events for which a causal relationship with vemurafenib could not be ruled out or was unknown. ADR data were collected for patients treated with vemurafenib (960 mg bid) between 26 February and 25 August 2015. Among 95 patients, 46 patients had 118 ADRs (24 serious ADRs in 13 patients). The most common serious ADRs were hypersensitivity (n = 1; 3 events), arthralgia (n = 2; 2 events), pyrexia (n = 2; 2 events) and drug eruption (n = 2; 2 events). Seven patients had serious skin disorders or hypersensitivity, six of whom had prior anti-programmed cell death-1 (PD-1) antibodies 5-35 days before starting vemurafenib. ADR reports of serious skin disorders appeared to be collected more rapidly than previously reported. Cutaneous squamous cell carcinoma developed in only one patient. EPPV in Japanese vemurafenib-treated patients identified no new safety signals. The most serious skin and hypersensitivity ADRs occurred in patients with prior anti-PD-1 exposure. Cutaneous squamous cell carcinoma appeared to be rare in Japanese patients. Further research is needed to clarify whether prior treatment with anti-PD-1 agents or racial differences affect the characteristic profile of cutaneous ADRs in Japanese patients.

Mineral trioxide aggregate as pulp dressing agent in pulpotomy treatment of primary molars: 42-month clinical study.

PubMed

Maroto, Myriam; Barbería, Elena; Vera, Vicente; García-Godoy, Franklin

2007-10-01

To evaluate the long-term clinical and radiographical results of using gray mineral trioxide aggregate (MTA) in pulpotomy treatments in primary molars. A total of 69 primary molars were treated with pulpotomy procedures using MTA and follow-up every 6 months up to 42 months. Clinical success was 100% as none of the molars showed clinical pathologic signs; radiographical success was 98.5% as one case of internal resorption was recorded. Reparative dentin deposition was found as stenosis of the pulp canals in 84% of the cases 42 months after treatment and as dentin bridge formation in 83% of the cases 42 months after treatment. Moreover, 11 permanent successors erupted at their normal exfoliation time without pathology after pulpotomy treatment with gray MTA of the primary molars.

A prospective clinical study of regenerative endodontic treatment of traumatized immature teeth with necrotic pulps using bi-antibiotic paste.

PubMed

Nazzal, H; Kenny, K; Altimimi, A; Kang, J; Duggal, M S

2018-04-01

To evaluate the treatment outcomes of a revitalization endodontic technique (RET) for the management of traumatized immature teeth with necrotic pulps in children. Fifteen healthy children (age range = 7-10 years) with traumatized immature maxillary incisors with necrotic pulps treated with bi-antibiotic revitalization endodontic technique were prospectively assessed over approximately two years (mean = 22 months). One operator undertook all treatments, clinical reviews and standardized radiographic exposures with radiographic analysis being carried out by two calibrated experienced clinicians. Crown colour change was assessed using an objective published methodology. Wilcoxon signed-rank test was used to compare root lengths, root dentinal widths and apical foramen widths over time. Interoperator measurement reliability was consistently strong for all measurements. There was no significant difference in root lengths or root dentinal wall widths following RET. A significant difference in apical foramen widths was observed after 2 years (P = 0.013) with resolution of clinical signs of infection in all cases. Despite omitting minocycline and using Portland cement (nonbismuth containing cement), a noticeable crown colour change (yellower, redder and lighter), as measured by an objective colour measurement system with ΔE = 7.39, was recorded. Most patients, however, were satisfied with the aesthetic outcome. Traumatized immature teeth with necrotic pulps treated with revitalization endodontic technique did not demonstrate continuation of root development or dentine formation when assessed by periapical radiographs. However, apical closure and periodontal healing were observed. A measurable change in crown colour (yellower, redder and lighter), with mostly no aesthetic concern to the patients/parents, was also observed. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Effect of Galla chinensis on the remineralization of two bovine root lesions morphous in vitro.

PubMed

Guo, Bin; Que, Ke-Hua; Jing Yang; Wang, Bo; Liang, Qian-Qian; Xie, Hong-Hui

2012-09-01

The present study aims to evaluate the effect of Galla chinensis compounds on the remineralization of two artificial root lesions morphous in vitro. Sixty bovine dentine blocks were divided into two groups and individually treated with two levels of demineralization solutions to form erosive and subsurface artificial carious lesions in vitro. Each group was then divided into three subgroups, each of which were treated with a remineralization solution (positive control), deionized water (negative control), or 4 000 mg⋅L(-1) aqueous solutions of Galla chinensis extract. The dentine blocks were then subjected to a pH-cycling regime for 7 days. During the first 4 days, the daily cycle included 21-h deal and 3-h demineralization applications. The dentine blocks were dealt with the entire day during the remaining 3 days. Two specimens from each of the treatment groups were selected and observed under a polarized light microscope. Data collected using a laser scanning confocal microscope were computerized and analyzed. Galla chinensis extract clearly enhanced the remineralization of both erosive lesion and subsurface lesion patterns in the specimens (P<0.05). The level of remineralization of the erosive lesion by Galla chinensis extract was lower than that of the subsurface lesion (P<0.05). In addition, the remineralization of the subsurface lesion by Galla chinensis extract was higher than that of the remineralization solution (P<0.05). No significant difference between the remineralization of erosive lesions by Galla chinensis extract and the remineralization solution was observed (P>0.05). So Galla chinensis extract has the potential to improve the remineralization of artificial root lesions under dynamic pH-cyclic conditions, indicating its potential use as a natural remineralization medicine.

Incidence of microcracks in maxillary first premolars after instrumentation with three different mechanized file systems: a comparative ex vivo study.

PubMed

Kfir, A; Elkes, D; Pawar, A; Weissman, A; Tsesis, I

2017-01-01

The objective of this study is to determine the potential for microcracks in the radicular dentin of first maxillary premolars using three different mechanized endodontic instrumentation systems. Eighty extracted maxillary first premolars with two root canals and no externally visible microcracks were selected. Root canal instrumentation was performed with either the ProTaper file system, the WaveOne primary file, or the self-adjusting file (SAF). Teeth with intact roots served as controls. The roots were cut into segments and examined with an intensive, small-diameter light source that was applied diagonally to the entire periphery of the root slice under ×20 magnification; the presence of microcracks and fractures was recorded. Pearson's chi-square method was used for statistical analysis, and significance was set at p < 0.05. Microcracks were present in 30 and 20 % of roots treated with the ProTaper and WaveOne systems, respectively, while no microcracks were present in the roots treated with the SAF (p = 0.008 and p = 0.035, respectively). Intact teeth presented with cracks in 5 % of the roots. The intensive, small-diameter light source revealed microcracks that could not be detected when using the microscope's light alone. Within the limitations of this study, it could be concluded that mechanized root canal instrumentation with the ProTaper and WaveOne systems in maxillary first premolars causes microcracks in the radicular dentin, while the use of the SAF file causes no such microcracks. Rotary and reciprocating files with large tapers may cause microcracks in the radicular dentin of maxillary first premolars. Less aggressive methods should be considered for these teeth.

The effect of dentin on the pulp tissue dissolution capacity of sodium hypochlorite and calcium hydroxide.

PubMed

Slutzky-Goldberg, Iris; Hanut, Aiham; Matalon, Shlomo; Baev, Valery; Slutzky, Hagay

2013-08-01

Sodium hypochlorite (NaOCl) and calcium hydroxide (Ca[OH]2) have tissue dissolution capacity. The aim of this study was to evaluate the potential effect of dentin on their tissue dissolution capacity in a novel dentin model. Dentin models were prepared from 25 freshly extracted human molar teeth; the crowns were separated from the roots, and a rectangular inner shape was prepared. Pulp tissue samples adjusted to similar weights of 6.5 ± 0.2 mg were randomly divided into 6 groups: NaOCl groups in test tubes or dentin models for 1 hour, Ca(OH)2 groups in test tubes or dentin models for 1 week, and control groups saline in test tubes or dentin models for 1 week. The final weights after the experimental period were checked and compared with the initial weights. The differences were statistically analyzed. The tissue dissolution capacity of Ca(OH)2 was affected by the presence of dentin. Similarly, NaOCl lost its effect on the pulp tissue after incubation in dentin. Comparison between all test groups showed highly significant differences (P < .001). Dentin has a detrimental effect on the ability of NaOCl and Ca(OH)2 to dissolve pulp tissue. The dentin model appears to be an efficient tool for the study of interactions between local endodontic medicaments, dentin, and pulp tissue. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Prostate Cancer Progression and Serum SIBLING (Small Integrin Binding N-Linked Glycoprotein)Levels

DTIC Science & Technology

2007-10-01

termed SIBLINGs (for small integrin binding ligand N-linked glycoproteins) whose members include bone sialoprotein (BSP), osteopontin (OPN), dentin...enzyme-linked immunosorbent assays (ELISAs) for quantitatively determining the levels of bone sialoprotein (BSP), osteopontin (OPN), dentin...synthesized as a chimeric protein, composed of three parts: dentin sialoprotein (DSP), dentin glycoprotein (DGP) and dentin phosphoprotein (DPP, also

Hierarchical structure and mechanical properties of remineralized dentin.

PubMed

Chen, Yi; Wang, Jianming; Sun, Jian; Mao, Caiyun; Wang, Wei; Pan, Haihua; Tang, Ruikang; Gu, Xinhua

2014-12-01

It is widely accepted that the mechanical properties of dentin are significantly determined by its hierarchical structure. The current correlation between the mechanical properties and the hierarchical structure was mainly established by studying altered forms of dentin, which limits the potential outcome of the research. In this study, dentins with three different hierarchical structures were obtained via two different remineralization procedures and at different remineralization stages: (1) a dentin structure with amorphous minerals incorporated into the collagen fibrils, (2) a dentin with crystallized nanominerals incorporated into the collagen fibrils, and (3) a dentin with an out-of-order mineral layer filling the collagen fibrils matrix. Nanoindentation tests were performed to investigate the mechanical behavior of the remineralized dentin slides. The results showed that the incorporation of the crystallized nanominerals into the acid-etched demineralized organic fibrils resulted in a remarkable improvement of the mechanical properties of the dentin. In contrast, for the other two structures, i.e. the amorphous minerals inside the collagen fibrils and the out-of-order mineral layer within the collagen fibrils matrix, the excellent mechanical properties of dentin could not be restored. Copyright © 2014 Elsevier Ltd. All rights reserved.

Co-distribution of cysteine cathepsins and matrix metalloproteases in human dentin.

PubMed

Scaffa, Polliana Mendes Candia; Breschi, Lorenzo; Mazzoni, Annalisa; Vidal, Cristina de Mattos Pimenta; Curci, Rosa; Apolonio, Fabianni; Gobbi, Pietro; Pashley, David; Tjäderhane, Leo; Tersariol, Ivarne Luis Dos Santos; Nascimento, Fábio Dupart; Carrilho, Marcela Rocha

2017-02-01

It has been hypothesized that cysteine cathepsins (CTs) along with matrix metalloproteases (MMPs) may work in conjunction in the proteolysis of mature dentin matrix. The aim of this study was to verify simultaneously the distribution and presence of cathepsins B (CT-B) and K (CT-K) in partially demineralized dentin; and further to evaluate the activity of CTs and MMPs in the same tissue. The distribution of CT-B and CT-K in sound human dentin was assessed by immunohistochemistry. A double-immunolabeling technique was used to identify, at once, the occurrence of those enzymes in dentin. Activities of CTs and MMPs in dentin extracts were evaluated spectrofluorometrically. In addition, in situ gelatinolytic activity of dentin was assayed by zymography. The results revealed the distribution of CT-B and CT-K along the dentin organic matrix and also indicated co-occurrence of MMPs and CTs in that tissue. The enzyme kinetics studies showed proteolytic activity in dentin extracts for both classes of proteases. Furthermore, it was observed that, at least for sound human dentin matrices, the activity of MMPs seems to be predominant over the CTs one. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biomimetic remineralization of dentin.

PubMed

Niu, Li-Na; Zhang, Wei; Pashley, David H; Breschi, Lorenzo; Mao, Jing; Chen, Ji-Hua; Tay, Franklin R

2014-01-01

Remineralization of demineralized dentin is important for improving dentin bonding stability and controlling primary and secondary caries. Nevertheless, conventional dentin remineralization strategy is not suitable for remineralizing completely demineralized dentin within hybrid layers created by etch-and-rinse and moderately aggressive self-etch adhesive systems, or the superficial part of a caries-affected dentin lesion left behind after minimally invasive caries removal. Biomimetic remineralization represents a different approach to this problem by attempting to backfill the demineralized dentin collagen with liquid-like amorphous calcium phosphate nanoprecursor particles that are stabilized by biomimetic analogs of noncollagenous proteins. This paper reviewed the changing concepts in calcium phosphate mineralization of fibrillar collagen, including the recently discovered, non-classical particle-based crystallization concept, formation of polymer-induced liquid-precursors (PILP), experimental collagen models for mineralization, and the need for using phosphate-containing biomimetic analogs for biomimetic mineralization of collagen. Published work on the remineralization of resin-dentin bonds and artificial caries-like lesions by various research groups was then reviewed. Finally, the problems and progress associated with the translation of a scientifically sound concept into a clinically applicable approach are discussed. The particle-based biomimetic remineralization strategy based on the PILP process demonstrates great potential in remineralizing faulty hybrid layers or caries-like dentin. Based on this concept, research in the development of more clinically feasible dentin remineralization strategy, such as incorporating poly(anionic) acid-stabilized amorphous calcium phosphate nanoprecursor-containing mesoporous silica nanofillers in dentin adhesives, may provide a promising strategy for increasing of the durability of resin-dentin bonding and remineralizing caries-affected dentin. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Grape seed extracts inhibit dentin matrix degradation by MMP-3

PubMed Central

Khaddam, Mayssam; Salmon, Benjamin; Le Denmat, Dominique; Tjaderhane, Leo; Menashi, Suzanne; Chaussain, Catherine; Rochefort, Gaël Y.; Boukpessi, Tchilalo

2014-01-01

Since Matrix metalloproteinases (MMPs) have been suggested to contribute to dentin caries progression, the hypothesis that MMP inhibition would affect the progression of dentin caries is clinically relevant. Grape seed extracts (GSE) have been previously reported to be natural inhibitors of MMPs. Objective: To evaluate the capacity of a GSE mouthrinse to prevent the degradation of demineralized dentin matrix by MMP-3 (stromelysin-1). Materials and Methods: Standardized blocks of dentin obtained from sound permanent teeth extracted for orthodontic reasons were demineralized with Ethylenediaminetetraacetic acid (EDTA) and pretreated either with (A) GSE (0.2% w/v), (B) amine fluoride (AmF) (20% w/v), (C) a mouthrinse which contains both, (D) placebo, (E) sodium fluoride (0.15 mg.ml−1), (F) PBS, (G) Chlorhexidine digluconate (CHX), or (H) zinc chloride (ZnCl2). The dentin blocks were then incubated with activated recombinant MMP-3. The supernatants were analyzed by Western Blot for several dentin matrix proteins known to be MMP-3 substrate. In parallel, scanning electron microscopy (SEM) was performed on resin replica of the dentin blocks. Results: Western blot analysis of the supernatants revealed that MMP-3 released from the dentin matrix small proteoglycans (decorin and biglycan) and dentin sialoprotein (DSP) in the AmF, sodium fluoride, PBS and placebo pretreated groups, but not in the GSE and mouthrinse pretreated groups. SEM examination of resin replica showed that the mouthrinse and its active components not only had an anti-MMP action but also modified the dentin surface accessibility. Conclusion: This study shows that GSE either alone or combined with AmF as in the evaluated mouthrinse limits dentin matrix degradation. This association may be promising to prevent the progression of caries within dentin. However, the procedure should be adapted to clinically relevant durations. PMID:25400590

Effect of a new desensitizing material on human dentin permeability.

PubMed

Rusin, Richard P; Agee, Kelli; Suchko, Michael; Pashley, David H

2010-06-01

Resin-modified glass ionomers (RMGI) have demonstrated clinical success providing immediate and long-term relief from root sensitivity. RMGIs have been recently introduced as paste-liquid systems for convenience of clinical usage. The objective of this study was to measure the ability of a new paste-liquid RMGI to reduce fluid flow through human dentin, compared to an established single-bottle nanofilled total etch resin adhesive indicated for root desensitization. Dentin permeability was measured on human crown sections on etched dentin, presenting a model for the exposed tubules typical of root sensitivity, and permitting measurement of the maximum permeability. In the first two groups, the etched dentin was coated with either the RMGI or adhesive, and permeability measured on the coated dentin. In a third group, a smear layer was created on the dentin with sandpaper, then the specimens were coated with the RMGI; permeability was measured on the smeared and coated dentin. Specimens from each group were sectioned and examined via scanning electron microscopy (SEM). Both the resin adhesive and the new paste-liquid RMGI protective material significantly reduced fluid flow through dentin, and exhibited excellent seal on dentin with either open tubules or smear-layer occluded tubules. The RMGI infiltrated the smear layer with resin during placement, penetrated dentin tubules, and formed resin tags. The RMGI was equivalent to the adhesive in its ability to reduce fluid flow and seal dentin. It is therefore concluded that the new RMGI and the adhesive show the potential to offer excellent sensitivity relief on exposed root dentin. Copyright (c) 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Patch-testing for the management of hypersensitivity reactions to second-line anti-tuberculosis drugs: a case report.

PubMed

Khan, Samsuddin; Andries, Aristomo; Pherwani, Asha; Saranchuk, Peter; Isaakidis, Petros

2014-08-15

The second-line anti-tuberculosis drugs used in the treatment of multidrug-resistant tuberculosis often cause adverse events, especially in patients co-infected with the human immunodeficiency virus. Severe hypersensitivity reactions due to these drugs are rare and there is little published experience to guide their management. A 17-year old Indian female multidrug-resistant tuberculosis patient co-infected with human immunodeficiency virus developed a hypersensitivity reaction after starting second-line anti-tuberculosis treatment in Mumbai, India. The patient was being treated with kanamycin, moxifloxacin, para-aminosalicylic acid, cycloserine, clofazimine, and amoxicillin-clavulanic acid. Twenty-four hours later, the patient developed generalized urticaria, morbilliform rash and fever. All drugs were suspended and the patient was hospitalised for acute management. Skin patch-testing was used to identify drugs that potentially caused the hypersensitivity reaction; results showed a strong reaction to clofazimine, moderate reaction to kanamycin and mild reaction to cycloserine. An interim second-line anti-tuberculosis regimen was prescribed; cycloserine and kanamycin were then re-challenged one-by-one using incremental dosing, an approach that allowed clinicians to re-introduce these drugs promptly and safely. The patient is currently doing well. This is the first case-report of a multidrug-resistant tuberculosis patient co-infected with the human immunodeficiency virus with hypersensitivity reaction to multiple second-line anti-tuberculosis drugs. Skin patch-testing and controlled re-challenge can be a useful management strategy in such patients. There is an urgent need for second-line anti-tuberculosis regimens that are more effective, safe and better tolerated.

Cermet reinforcement of a weakened endodontically treated root: a case report.

PubMed

Lui, J L

1992-08-01

Many clinical applications have been recommended for glass-cermet cement because of its improved properties compared to the original glass-ionomer cements. It has also been accepted as a dentinal substitute that can strengthen teeth. In this paper, an additional clinical application for glass-cermet cement, the reinforcement of weakened endodontically treated roots, is suggested. This technique is in keeping with the trends of tooth conservation and the use of an adhesive restorative material in the restoration of severely damaged teeth by a conservative approach.

[Advantages and disadvantages of endocrown restorations of endodontically treated teeth with large coronal destruction].

PubMed

Bao, X D

2018-04-09

The strength of endodontically treated teeth were reduced apparently because of structural damage, therefore further reduction of healthy tissue should be avoided as much as possible in restoration. Endocrown made by chair-side CAD/CAM is some kind of minimal invasive restoration, and the retention of restoration is achieved by reliable bonding and macromechanial retention forces. Without post preparation, the root structure could be resevered. Following the indications and use of biomechanical dentin-like CAD/CAM materials could reduce the adverse effect of tensile stress on cervical part.

Stress distribution of endodontically treated teeth with titanium alloy post and carbon fiber post with different alveolar bone height: A three-dimensional finite element analysis.

PubMed

Singh, S Vijay; Bhat, Manohar; Gupta, Saurabh; Sharma, Deepak; Satija, Harsha; Sharma, Sumeet

2015-01-01

A three-dimensional (3D) finite element analysis (FEA) on the stress distribution of endodontically treated teeth with titanium alloy post and carbon fiber post with different alveolar bone height. The 3D model was fabricated using software to represent an endodontically treated mandibular second premolar with post and restored with a full ceramic crown restoration, which was then analyzed using FEA using FEA ANSYS Workbench V13.0 (ANSYS Inc., Canonsburg, Pennsylvania, U.S.A) software. The FEA showed the maximum stresses of 137.43 Mpa in dentin with alveolar bone height of 4 mm when the titanium post was used, 138.48 Mpa when carbon fiber post was used as compared to 105.91 Mpa in the model with alveolar bone height of 2 mm from the cement enamel junction (CEJ) when the titanium post was used and 107.37 Mpa when the carbon fiber post was used. Stress was observed more in alveolar bone height level of 4 mm from CEJ than 2 mm from CEJ. Stresses in the dentin were almost similar when the carbon fiber post was compared to titanium post. However, stresses in the post and the cement were much higher when titanium post was used as compared to carbon fiber post.

Influence of Immediate Dentin Sealing on the Shear Bond Strength of Pressed Ceramic Luted to Dentin with Self-Etch Resin Cement

PubMed Central

Dalby, Robert; Ellakwa, Ayman; Millar, Brian; Martin, F. Elizabeth

2012-01-01

Objectives. To examine the effect of immediate dentin sealing (IDS), with dentin bonding agents (DBAs) applied to freshly cut dentin, on the shear bond strength of etched pressed ceramic luted to dentin with RelyX Unicem (RXU) cement. Method. Eighty extracted noncarious third molars were ground flat to expose the occlusal dentin surfaces. The teeth were randomly allocated to five groups (A to E) of sixteen teeth each. Groups A to D were allocated a dentin bonding agent (Optibond FL, One Coat Bond, Single Bond, or Go!) that was applied to the dentin surface to mimic the clinical procedure of IDS. These specimen groups then had etched glass ceramic discs (Authentic) luted to the sealed dentin surface using RXU. Group E (control) had etched glass ceramic discs luted to the dentin surface (without a dentin bonding agent) using RXU following the manufacturer's instructions. All specimens were stored for one week in distilled water at room temperature and then shear stressed at a constant cross-head speed of 1 mm per minute until failure. Statistical analysis was performed by ANOVA followed by post hoc Tukey HSD method (P < 0.05) applied for multiple paired comparisons. Results. The shear bond strength results for group A to E ranged from 6.94 ± 1.53 to 10.03 ± 3.50 MPa. One-way ANOVA demonstrated a difference (P < 0.05) between the groups tested and the Tukey HSD demonstrated a significant (P < 0.05) difference between the shear bond strength (SBS) of Optibond FL (Group A) and Go! (Group D). There was no statistical difference (P > 0.05) in the SBS between the test groups (A–D) or the control (group E). Conclusion. IDS using the dentin bonding agents tested does not statistically (P > 0.05) affect the shear bond strength of etched pressed ceramic luted to dentin with RXU when compared to the control. PMID:22287963

Morphological Analysis of Dentin Surface after Conditioning with Two Different methods: Chemical and Mechanical.

PubMed

Rafael, Caroline Freitas; Quinelato, Valquíria; Morsch, Carolina Schaffer; DeDeus, Gustavo; Reis, Claudia Mendonca

2016-01-01

Alternative pretreatment strategies of dentin and adhesionare constantly being developed and studied with the goal of improving the adhesion of resin restorative materials with this tissue. The objectives of the present study were to evaluate the ability of airborne-particle abrasion (APA) with aluminum oxide on dentin to remove the smear layer and the effects produced on the dentin microstructure. The phosphoric acid (PA) was used for a comparison. For that, 20 human third molars were randomly allocated into two experimental groups, according to the dentin pretreatment method used: G1 (N = 10) - PA, G2 (N = 10) -APA. For dentin surface analyses, an environmental scanning electron microscope (ESEM) was employed to observe dentin surfaces before and after the procedures. Before pretreatment, the specimens of both groups were smear covered. After pretreatment, the G1 images revealed dentin tubule orifices opened, enlarged and some erosive effects. (G2) exposed tubule orifices without enlargement, but crack-like alterations were observed on the surfaces. In this way, APA with aluminum oxide was able to remove the smear layer. The influences of the dentin roughness on adhesion and the consequences on dentin integrity and hardness need further investigations. A good conditioning of the dentin before cementation is necessary in order to obtain a satisfactory rehabilitation in adhesive dentistry. So, it is necessary to know all methods to do it.

Prevention of water-contamination of ethanol-saturated dentin and hydrophobic hybrid layers

PubMed Central

Sauro, Salvatore; Watson, Timothy F; Mannocci, Francesco; Tay, Franklin R; Pashley, David H

2013-01-01

SUMMARY Purpose This in vitro study evaluated the amount and the distribution of outward fluid flow that occurred when an experimental etch-and-rinse hydrophobic adhesive was applied to ethanol-saturated dentin before and after oxalate pretreatment. Materials and methods Measurements of dentin permeability were performed under a constant pulpal pressure of 20 cm H2O in deep and middle dentin. A lucifer yellow solution was placed in the pulp chamber to determine the distribution of the water contamination of the hybrid layers. Results The distribution of fluorescence in dentin specimens that were not pretreated with oxalate revealed that the dye permeated around the resin tags and filled the hybrid layer. Dentin specimens pretreated with oxalate prior to resin bonding, showed 80–83% less (p<0.05) water contamination compared to controls. The dentin permeability results obtained before and after oxalate pretreatment showed that oxalate decreased dentin permeability by 98% (p<0.05) compared to acid-etched controls. This prevented outward fluid movement during bonding resulting in better resin sealing of dentin due to the formation of a double seal of resin tags over calcium oxalate crystals in the tubules. Conclusion Outward dentinal fluid flow may contaminate hybrid layers during adhesive bonding procedures. Pretreatment of acid-etched dentin with 3% oxalic acid prior to bonding procedures can prevent outward fluid flow during bonding and water contamination of the hydrophobic hybrid layers. PMID:19701507

Zinc-Containing Restorations Create Amorphous Biogenic Apatite at the Carious Dentin Interface: A X-Ray Diffraction (XRD) Crystal Lattice Analysis.

PubMed

Toledano, Manuel; Aguilera, Fátima S; López-López, Modesto T; Osorio, Estrella; Toledano-Osorio, Manuel; Osorio, Raquel

2016-10-01

The aim of this research was to assess the ability of amalgam restorations to induce amorphous mineral precipitation at the caries-affected dentin substrate. Sound and caries-affected dentin surfaces were subjected to both Zn-free and Zn-containing dental amalgam restorations. Specimens were submitted to thermocycling (100,000 cycles/5°C-55°C, 3 months). Dentin surfaces were studied by atomic force microscopy (nanoroughness), X-ray diffraction, field emission scanning electron microscopy, and energy-dispersive analysis, for physical and morphological surface characterization. Zn-containing amalgam placement reduced crystallinity, crystallite size, and grain size of calcium phosphate crystallites at the dentin surface. Both microstrain and nanoroughness were augmented in caries-affected dentin restored with Zn-containing amalgams. Caries-affected dentin showed the shortest mineral crystallites (11.04 nm), when Zn-containing amalgams were used for restorations, probably leading to a decrease of mechanical properties which might favor crack propagation and deformation. Sound dentin restored with Zn-free amalgams exhibited a substantial increase in length of grain particles (12.44 nm) embedded into dentin crystallites. Zn-containing amalgam placement creates dentin mineralization and the resultant mineral was amorphous in nature. Amorphous calcium phosphate provides a local ion-rich environment, which is considered favorable for in situ generation of prenucleation clusters, promotong further dentin remineralization.

[Hypersensitivity to dacarbazine in patients with metastatic malignant melanoma].

PubMed

Levy, A; Guitera, P; Kerob, D; Ollivaud, L; Archimbaud, A; Dubertret, L; Basset-Seguin, N

2006-02-01

Dacarbazine (DTIC) is the first-line chemotherapy for metastatic malignant melanoma without cerebral metastasis. Its clinical and hematological safety is usually good. Hypersensitivity in hepatic failure patients is the most serious side effect described. This was a retrospective study of the prevalence of hypersensitivity in patients treated with DTIC for metastatic melanoma between 11/01/2002 and 10/31/2003. Hypersensitivity was diagnosed in the event of fever, hypereosinophilia (> 500/mm3) with or without liver dysfunction (> twice pre-therapeutic values). Clinical data, DTIC administration modalities, number of courses and clinical and laboratory safety data were recorded. Twenty patients were included, 11 women and 9 men of median age 58.6 years (22-82 years) with multiple metastases in all cases. DTIC was the first-line treatment for 19 patients, being administered for 4 days to 10 patients and for 1 day to the other 10 patients, depending on their overall health status. Five hypersensitivity-like manifestations were observed, all in the 4-day treatment group. In 3 patients, fever and hypereosinophilia were seen without liver dysfunction at D3 of the second course of treatment. In 2 patients, treatment was stopped after the second course because of disease progression. In the third patient, 4 courses were given with recurrence of symptoms, although the latter were controlled during the fifth course with corticosteroids and antihistamines given 15 minutes before the start of treatment. Two patients experienced severe forms of hypersensitivity with fever, hypereosinophilia, liver dysfunction (cytolysis and cholestasis) and delayed medullar aplasia, after the first and second course respectively. In one patient, bone marrow examination showed a block at the promyelocytic stage consistent with a toxic etiology. Treatment with DTIC was stopped, and all signs regressed with symptomatic treatment. Hypersensitivity with DTIC seems to be frequent, being observed in 20% of our patients, with early onset (after the first or second course) and absence of dose-dependence. We describe for the first time two cases of medullar aplasia occurring in association with DTIC hypersensitivity. During phase I studies, the hematologic toxicity of DTIC was moderate, rarely affecting red cells, and was observed with higher doses than those used in metastatic malignant melanoma. We suggest that this aplasia forms part of the signs of hypersensitivity because of the bone marrow morphology, the existence of anemia and concomitant resolution with all the others signs of hypersensitivity. Laboratory monitoring (NFS, liver enzymes) is thus justified, particularly after the first and second courses of DTIC. In case of fever and hypereosinophilia without liver dysfunction, DTIC may be continued together with symptomatic treatment. In the event of hepatic dysfunction, and of course severe hematological disorders, potentially fatal complications can occur and treatment must be stopped.

Previous Cocaine Exposure Makes Rats Hypersensitive to Both Delay and Reward Magnitude

PubMed Central

Roesch, Matthew R.; Takahashi, Yuji; Gugsa, Nishan; Bissonette, Gregory B.; Schoenbaum, Geoffrey

2008-01-01

Animals prefer an immediate over a delayed reward, just as they prefer a large over a small reward. Exposure to psychostimulants causes long-lasting changes in structures critical for this behavior and might disrupt normal time-discounting performance. To test this hypothesis, we exposed rats to cocaine daily for 2 weeks (30 mg/kg, i.p.). Approximately 6 weeks later, we tested them on a variant of a time-discounting task, in which the rats responded to one of two locations to obtain reward while we independently manipulated the delay to reward and reward magnitude. Performance did not differ between cocaine-treated and saline-treated (control) rats when delay lengths and reward magnitudes were equal at the two locations. However, cocaine-treated rats were significantly more likely to shift their responding when we increased the delay or reward size asymmetrically. Furthermore, they were slower to respond and made more errors when forced to the side associated with the lower value. We conclude that previous exposure to cocaine makes choice behavior hypersensitive to differences in the time to and size of available rewards, consistent with a general effect of cocaine exposure on reward valuation mechanisms. PMID:17202492

Previous cocaine exposure makes rats hypersensitive to both delay and reward magnitude.

PubMed

Roesch, Matthew R; Takahashi, Yuji; Gugsa, Nishan; Bissonette, Gregory B; Schoenbaum, Geoffrey

2007-01-03

Animals prefer an immediate over a delayed reward, just as they prefer a large over a small reward. Exposure to psychostimulants causes long-lasting changes in structures critical for this behavior and might disrupt normal time-discounting performance. To test this hypothesis, we exposed rats to cocaine daily for 2 weeks (30 mg/kg, i.p.). Approximately 6 weeks later, we tested them on a variant of a time-discounting task, in which the rats responded to one of two locations to obtain reward while we independently manipulated the delay to reward and reward magnitude. Performance did not differ between cocaine-treated and saline-treated (control) rats when delay lengths and reward magnitudes were equal at the two locations. However, cocaine-treated rats were significantly more likely to shift their responding when we increased the delay or reward size asymmetrically. Furthermore, they were slower to respond and made more errors when forced to the side associated with the lower value. We conclude that previous exposure to cocaine makes choice behavior hypersensitive to differences in the time to and size of available rewards, consistent with a general effect of cocaine exposure on reward valuation mechanisms.

The effect of dentinal stimulation on pulp nerve function and pulp morphology in the dog.

PubMed

Hirvonen, T J; Närhi, M V

1986-11-01

The effect of dentinal stimulation on pulpal nerve responses and pulp morphology has been studied in the dog. Canine tooth (n = 25) dentin was stimulated by drilling, probing, and air-blasting for from two to five hours. Acid-etching was used to open dentinal tubules. All test teeth showed disruption of the odontoblast layer and its separation from the predentin; also, dislocation of odontoblast nuclei into dentinal tubules was found in most cases. Single-fiber (n = 14, conduction velocity = 24.3 +/- 7.4 (SD) m/s) recordings of the responses of canine tooth pulpal nerves to dentinal stimulation were made in ten of the stimulated teeth. No changes in the sensitivity of the nerves to dentinal stimulation could be detected. It is concluded that pulpal nerve function and morphological changes of the pulp are not clearly correlated. The condition of the dentin surface seems to be the important factor.

Deformation behavior of human dentin in liquid nitrogen: a diametral compression test.

PubMed

Zaytsev, Dmitry; Panfilov, Peter

2014-09-01

Contribution of the collagen fibers into the plasticity of human dentin is considered. Mechanical testing of dentin at low temperature allows excluding the plastic response of its organic matrix. Therefore, deformation and fracture behavior of the dentin samples under diametral compression at room temperature and liquid nitrogen temperature are compared. At 77K dentin behaves like almost brittle material: it is deformed exclusively in the elastic regime and it fails due to growth of the sole crack. On the contrary, dentin demonstrates the ductile response at 300K. There are both elastic and plastic contributions in the deformation of dentin samples. Multiple cracking and crack tip blunting precede the failure of samples. Organic phase plays an important role in fracture of dentin: plasticity of the collagen fibers could inhibit the crack growth. Copyright © 2014 Elsevier B.V. All rights reserved.

Evaluation of tartar control dentifrices in in vitro models of dentin sensitivity.

PubMed

Mason, S; Levan, A; Crawford, R; Fisher, S; Gaffar, A

1991-01-01

The effects of anticalculus dentifrices were compared with other commercially available dentifrices in in vitro models of dentin sensitivity. Changes in the hydraulic conductance of dentin discs were measured with and without a smear layer before and after treatment and also after a post-treatment acid etch. The capacity of dentifrices to occlude open dentinal tubules in vitro was also assessed by scanning electron microscopy (SEM). There was good correlation (R = 0.98) between our test and values reported in the literature. Tartar control dentifrices gave reductions in fluid flow rates through the dentin discs comparable to those obtained with Promise, Sensodyne, Thermodent and Denquel. Additionally, tartar control dentifrices did not remove microcrystalline debris (smear layers) from the surfaces of dentin in vitro. These results were confirmed by SEM. Thus, according to the hydrodynamic theory of dentin sensitivity, these in vitro results suggest that pyrophosphate-containing dentifrices should reduce dentinal sensitivity.

Effect of surface treatment of fiberglass posts on bond strength to root dentin.

PubMed

Valdivia, Andréa Dolores Correia Miranda; Novais, Veridiana Resende; Menezes, Murilo de Sousa; Roscoe, Marina Guimarães; Estrela, Carlos; Soares, Carlos José

2014-01-01

This study evaluated the influence of the surface treatments of fiberglass posts on bond strength to root dentin using push-out test. Forty bovine incisor roots were endodontically treated. The surface of the fiberglass posts (Exacto #2, Angelus) were treated using 4 different protocols (n=10): Control - 70% ethanol for 1 min; 37% phosphoric acid for 1 min; 10% hydrofluoric acid for 1 min; and 24% hydrogen peroxide for 1 min. After a silane coupling agent was applied for 1 min and all posts were cemented using self-adhesive resin cement (RelyX Unicem, 3M-ESPE). The roots were sectioned and two 1-mm-thick slices were obtained from each third: cervical, middle and apical. The specimens were subjected to the push-out test with a crosshead speed of 0.5 mm/min. Data were analyzed by repeated measures ANOVA followed by Tukey's HSD tests (=0.05). The surface treatment (p<0.001) and root third region (p=0.007) factors were significant. The retention to root canal was affected by surface treatment type. The post surface treatment with 24% hydrogen peroxide for 1 min yielded significantly higher bond strength when the fiberglass posts were cemented with RelyX Unicem.

Inhibition of the Quorum Sensing System (ComDE Pathway) by Aromatic 1,3-di-m-tolylurea (DMTU): Cariostatic Effect with Fluoride in Wistar Rats

PubMed Central

Kaur, Gurmeet; Balamurugan, P.; Princy, S. Adline

2017-01-01

Dental caries occurs as a result of dysbiosis among commensal and pathogenic bacteria leading to demineralization of enamel within a dental biofilm (plaque) as a consequence of lower pH in the oral cavity. In our previous study, we have reported 1,3-disubstituted ureas particularly, 1,3-di-m-tolylurea (DMTU) could inhibit the biofilm formation along with lower concentrations of fluoride (31.25 ppm) without affecting bacterial growth. In the present study, RT-qPCR analysis showed the target specific molecular mechanism of DMTU. In vivo treatment with DMTU, alone or in combination with fluoride, resulted in inhibition of caries (biofilm development of Streptococcus mutans) using a Wistar rat model for dental caries. The histopathological analysis reported the development of lesions on dentine in infected subjects whereas the dentines of treated rodents were found to be intact and healthy. Reduction in inflammatory markers in rodents' blood and liver samples was observed when treated with DMTU. Collectively, data speculate that DMTU is an effective anti-biofilm and anti-inflammatory agent, which may improve the cariostatic properties of fluoride. PMID:28748175

Inhibition of the Quorum Sensing System (ComDE Pathway) by Aromatic 1,3-di-m-tolylurea (DMTU): Cariostatic Effect with Fluoride in Wistar Rats.

PubMed

Kaur, Gurmeet; Balamurugan, P; Princy, S Adline

2017-01-01

Dental caries occurs as a result of dysbiosis among commensal and pathogenic bacteria leading to demineralization of enamel within a dental biofilm (plaque) as a consequence of lower pH in the oral cavity. In our previous study, we have reported 1,3-disubstituted ureas particularly, 1,3-di-m-tolylurea (DMTU) could inhibit the biofilm formation along with lower concentrations of fluoride (31.25 ppm) without affecting bacterial growth. In the present study, RT-qPCR analysis showed the target specific molecular mechanism of DMTU. In vivo treatment with DMTU, alone or in combination with fluoride, resulted in inhibition of caries (biofilm development of Streptococcus mutans ) using a Wistar rat model for dental caries. The histopathological analysis reported the development of lesions on dentine in infected subjects whereas the dentines of treated rodents were found to be intact and healthy. Reduction in inflammatory markers in rodents' blood and liver samples was observed when treated with DMTU. Collectively, data speculate that DMTU is an effective anti-biofilm and anti-inflammatory agent, which may improve the cariostatic properties of fluoride.

Caries-removal effectiveness of a papain-based chemo-mechanical agent: A quantitative micro-CT study.

PubMed

Neves, Aline A; Lourenço, Roseane A; Alves, Haimon D; Lopes, Ricardo T; Primo, Laura G

2015-01-01

The aim of this study was to access the effectiveness and specificity of a papain-based chemo-mechanical caries-removal agent in providing minimum residual caries after cavity preparation. In order to do it, extracted carious molars were selected and scanned in a micro-CT before and after caries-removal procedures with the papain-based gel. Similar parameters for acquisition and reconstruction of the image stacks were used between the scans. After classification of the dentin substrate based on mineral density intervals and establishment of a carious tissue threshold, volumetric parameters related to effectiveness (mineral density of removed dentin volume and residual dentin tissue) and specificity (relation between carious dentin in removed volume and initial caries) of this caries-removal agent were obtained. In general, removed dentin volume was similar or higher than the initial carious volume, indicating that the method was able to effectively remove dentin tissue. Samples with an almost perfect accuracy in carious dentin removal also showed an increased removal of caries-affected tissue. On the contrary, less or no affected dentin was removed in samples where some carious tissue was left in residual dentin. Mineral density values in residual dentin were always higher or similar to the threshold for mineral density values in carious dentin. In conclusion, the papain-based gel was effective in removing carious dentin up to a conservative in vitro threshold. Lesion characteristics, such as activity and morphology of enamel lesion, may also influence caries-removal properties of the method. © Wiley Periodicals, Inc.

The interrelationship of microstructure and hardness of human coronal dentin using reference point indentation technique and micro-Raman spectroscopy.

PubMed

Seyedmahmoud, Rasoul; McGuire, Jacob D; Wang, Yong; Thiagarajan, Ganesh; Walker, Mary P

2017-10-01

The aim of this paper is to determine the interrelationship between the microstructure - in terms of chemical composition and crystallinity - to the microhardness of coronal dentin. Dentin microhardness was tested by a novel reference point indenter and compared to the traditional Knoop hardness method. Micro-Raman spectroscopy was used to determine the chemical composition and crystallinity of dentin. From the occlusal groove to the border of the coronal pulp chamber, dentin hardness decreased from superficial dentin (SD) to deep dentin (DD). Mineral/organic matrix ratios (phosphate/CH and phosphate/amide I) also decreased from SD to DD; however, this change was significant (P<0.05) in the phosphate/amide I ratio only. The phosphate/carbonate ratio decreased significantly by varying position from SD to DD. The degree of the crystallinity, as measured by the full width at half maximum (FWHM) of the peak at 960cm -1 , decreased significantly going from superficial to deep dentin. For the first time, the interrelationship between the microstructure and the mechanical properties of coronal dentin was determined by using the novel reference point indentation technique and micro-Raman spectroscopy. We hypothesize that the decrease in hardness from superficial to deep dentin can potentially be explained by decreased mineral content and increased carbonate content, which is also associated with decreased crystallinity. Collectively, there is a positive association between dentin hardness and mineral content and a negative association between dentin hardness and carbonate content. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Enhanced differentiation of dental pulp cells cultured on microtubular polymer scaffolds in vitro.

PubMed

Haeri, Morteza; Sagomonyants, Karen; Mina, Mina; Kuhn, Liisa T; Goldberg, A Jon

2017-06-01

Dental caries (tooth decay) is the most common chronic disease. Dental tissue engineering is a promising alternative approach to alleviate the shortcomings of the currently available restorative materials. Mimicking the natural extracellular matrix (ECM) could enhance the performance of tissue engineering scaffolds. In this study, we developed microtubular (~20 μm diameter) polymethyl methacrylate (PMMA) scaffolds resembling the tubular (~2.5 μm diameter) structure of dentin, the collagen-based mineralized tissue that forms the major portion of teeth, to study the effect of scaffold architecture on differentiation of mouse dental pulp cells in vitro . Flat (control), plasma-treated solid and microtubular PMMA scaffolds with densities of 240±15, 459±51 and 480±116 tubules/mm 2 were first characterized using scanning electron microscopy and contact angle measurements. Dental pulp cells were cultured on the surface of the scaffolds for up to 21 days and examined using various assays. Cell proliferation and mineralization were examined using Alamar Blue and Xylenol Orange (XO) staining assays, respectively. The differentiation of pulp cells into odontoblasts was examined by immunostaining for Nestin and by quantitative PCR analysis for dentin matrix protein 1 ( Dmp1 ), dentin sialophosphoprotein ( Dspp ) and osteocalcin ( Ocn ). Our results showed that the highest tubular density scaffolds significantly (p<0.05) enhanced differentiation of pulp cells into odontoblasts as compared to control flat scaffolds, as evidenced by increased expression of Nestin (5.4x). However, mineralization was suppressed on all surfaces, possibly due to low cell density. These results suggest that the microtubular architecture may be a desirable feature of scaffolds developed for clinical applications. Regenerative engineering of diseased or traumatized tooth structure could avoid the deficiencies of traditional dental restorative (filling) materials. Cells in the dental pulp have the potential to differentiate to dentin-producing odontoblast cells. Furthermore, cell-supporting scaffolds that mimic a natural extracellular matrix (ECM) are known to influence behavior of progenitor cells. Accordingly, we hypothesized that a dentin-like microtubular scaffold would enhance differentiation of dental pulp cells. The hypothesis was proven true and differentiation to odontoblasts increased with increasing density of the microtubules. However, mineralization was suppressed, possibly due to a low density of cells. The results demonstrate the potential benefits of a microtubular scaffold design to promote odontoblast cells for regeneration of dentin.

Comparative safety of intravenous Ferumoxytol versus Ferric Carboxymaltose for the Treatment of Iron Deficiency Anemia: rationale and study design of a randomized double-blind study with a focus on acute hypersensitivity reactions.

PubMed

Adkinson, N Franklin; Strauss, William E; Bernard, Kristine; Kaper, Robert F; Macdougall, Iain C; Krop, Julie S

2017-01-01

Intravenous (IV) iron is often used to treat iron deficiency anemia in patients who are unable to tolerate or are inadequately managed with oral iron. However, IV iron treatment has been associated with acute hypersensitivity reactions. The comparative risk of adverse events (AEs) with IV iron preparations has been assessed by a few randomized controlled trials, which are most often limited by small patient numbers, which lack statistical power to identify differences in low-frequency AE such as hypersensitivity reactions. Ferumoxytol versus Ferric Carboxymaltose for the Treatment of Iron Deficiency Anemia (FIRM) is a randomized, double-blind, international, multicenter, Phase III study designed to compare the safety of ferumoxytol and ferric carboxymaltose (FCM). The study includes adults with hemoglobin <12.0 g/dL (females) or <14.0 g/dL (males), transferrin saturation ≤20% or ferritin ≤100 ng/mL within 60 days of dosing, and a history of unsatisfactory or nontolerated oral iron therapy or in whom oral iron therapy is inappropriate. Patients are randomized (1:1) to ferumoxytol 510 mg or FCM 750 mg, each given intravenously on days 1 and 8. Primary end points are the incidence of moderate-to-severe hypersensitivity reactions, including anaphylaxis, and moderate-to-severe hypotension. All potential hypersensitivity and hypotensive reactions will be adjudicated by a blinded, independent Clinical Events Committee. A secondary safety end point is the composite frequency of moderate-to-severe hypersensitivity reactions, including anaphylaxis, serious cardiovascular events, and death. Secondary efficacy end points include mean change in hemoglobin and mean change in hemoglobin per milligram of iron administered from baseline to week 5. Urinary excretion of phosphorus and the occurrence of hypophosphatemia after IV iron administration will be examined as well as the mechanisms of such hypophosphatemia in a substudy. FIRM will provide data on the comparative safety of ferumoxytol and FCM, two IV iron preparations with similar dosing schedules, focusing on moderate-to-severe hypersensitivity reactions, including anaphylaxis, and moderate-to-severe hypotension. The study plans to enroll 2000 patients and is expected to complete in 2017.

Nanomechanical properties of biochemically modified dentin bonded interfaces

PubMed Central

dos Santos, Paulo H; Karol, Sachin; Bedran-Russo, Ana Karina B

2014-01-01

Summary The effect of biomodification of dentin matrices using collagen cross-linkers, glutaraldehyde (GD) and grape seed extract (GSE), on the reduced modulus of elasticity (Er) and nanohardness (H) of the hybrid layer and underlying dentin was investigated at the dentin-resin bonded interface. The coronal dentin of nine molars were exposed and divided into groups: 5% GD, 6.5% GSE and control. Control samples were etched, bonded with Adper Single Bond Plus and Premise composite. GD and GSE were applied for 1 hour prior to bonding procedures. After 24 hours, samples were sectioned, and resin-dentin beams were either kept in distilled water or exposed to collagenase treatment for 24 hours. Nano-indentations were performed at the hybrid layer and underlying dentin. GD and GSE treatment increased the Er and H of resin-dentin interface structures when compared to the control group (p < 0.05), particularly the hybrid layer, and may be a promising novel approach to strengthen the dentin-resin bonded interface structures when using these adhesive system and resin-based composite. PMID:21058972