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Sample records for calcium hydroxide pastes

  1. Intratubular disinfection with tri-antibiotic and calcium hydroxide pastes.

    PubMed

    Pereira, Thais Cristina; Vasconcelos, Layla Reginna Silva Munhoz De; Graeff, Marcia Sirlene Zardin; Duarte, Marco Antonio Hungaro; Bramante, Clóvis Monteiro; Andrade, Flaviana Bombarda De

    2017-03-01

    The aim of this study was to compare the in vitro intradentinal antimicrobial ability of the calcium hydroxide and tri-antibiotic pastes. Standard bovine dentin tubes were sterilized and then infected with Enterococcus faecalis by a new contamination protocol of great depths of dentin. The specimens were filled with the medications, divided into two test-groups: calcium hydroxide (Group 1) and tri-antibiotic (Group 2) pastes. After 15 days, the teeth were evaluated by microbiological culture and confocal laser scanning microscopy (CLSM) with viability dye assay LIVE/DEAD inside dentinal tubules. In experiment of culture, the bacterial collection of the dentin fragments was done for counting the colony-forming units. The tri-antibiotic paste had a slightly greater antimicrobial effect; however, there was no statistical difference between the groups. It was concluded that the tri-antibiotic paste and the calcium hydroxide paste exercise the same effect on intra-tubular decontamination against E. faecalis. So, due the multiples advantages, the calcium hydroxide paste can be the choice for dentinal decontamination in regenerative procedures.

  2. Calcium hydroxide paste in the maxillary sinus: a case report.

    PubMed

    Fava, L R

    1993-09-01

    A case is reported in which a perforation of the sinus floor of the maxillary sinus occurred with extrusion of a calcium hydroxide paste during routine root canal treatment of a maxillary premolar. All clinical manifestations are described as well as the results of a follow-up evaluation.

  3. Assessment of ion diffusion from a calcium hydroxide-propolis paste through dentin.

    PubMed

    Montero, Janaina Corazza; Mori, Graziela Garrido

    2012-01-01

    This study evaluated the ability of ions from a non-alcoholic calcium hydroxide-propolis paste to diffuse through dentinal tubules. Thirty-six single-rooted bovine teeth were used. The tooth crowns were removed, and the root canals were instrumented and divided into 3 groups: Group 1 - calcium hydroxide-propylene glycol paste; Group 2 - calcium hydroxide-saline solution paste; Group 3 - calcium hydroxide-propolis paste. After the root canal dressings were applied, the teeth were sealed and placed in containers with deionized water. The pH of the water was measured after 3, 24, 72 and 168 hours to determine the diffusion of calcium hydroxide ions through the dentinal tubules. All of the pastes studied promoted the diffusion of calcium hydroxide ions through the dentinal tubules. Associating propolis to calcium hydroxide resulted in a pH increase, which occurred with greater intensity after 72 hours. The calcium hydroxide-propolis paste was able to diffuse in dentin.

  4. Evaluation of pH and calcium ion diffusion from calcium hydroxide pastes and MTA.

    PubMed

    Sáez, María Del M; López, Gabriela L; Atlas, Diana; de la Casa, María L

    2017-04-01

    The aim of this ex vivo study was to evaluate changes in pH and calcium ion diffusion through root dentin from calcium hydroxide (Ca (OH) 2) and mineral trioxide aggregate (MTA) pastes at 7, 30 and 60 days; and the relationship between pH and ion diffusion. Thirty-two human premolars were used. Crowns were sectioned and root canals instrumented and filled in with the following preparations: 1) Ca(OH) 2 + distilled water (n=7); 2) Ca(OH) 2 + 0.1% chlorhexidine gluconate (n=7); 3) MTA + distilled water (n=7); 4) MTA + 0.1% chlorhexidine gluconate (CHX) (n=7); 5) distilled water (n=2) (control); 6) 0.1% chlorhexidine gluconate (n=2) (control). The apex and coronary opening were sealed with IRM. Roots were placed in Eppendorf tubes with 1 ml distilled water at 37°C and 100% humidity. At baseline, 7, 30 and 60 days, pH was measured with pH meter, and calcium ion content in the solution was analyzed by atomic absorption spectrophotometry. The data were statistically analyzed using ANOVA, simple linear regression analysis and Pearson's correlation test. The highest pH values were achieved with calcium hydroxide pastes at 60 days (p ≤ 0.05). Calcium ions were released in all groups. The calcium hydroxide paste with distilled water at 60 days had the highest calcium ion value (p ≤ 0.01). There was a positive correlation between calcium and pH values. Sociedad Argentina de Investigación Odontológica.

  5. A Comparative Study of Ion Diffusion from Calcium Hydroxide with Various Herbal Pastes through Dentin

    PubMed Central

    Dhirawani, Rajesh B; Marya, Jayant; Dhirawani, Vrinda; Kumar, Vijayendra

    2017-01-01

    Aim The aim of this study was to evaluate the diffusion ability of ions through dentinal tubules of different nonalcoholic calcium hydroxide-containing herbal pastes and compare it with the calcium hydroxide paste prepared with saline. Materials and methods A total of 36 single-rooted premolar teeth were used in this study. The tooth crowns were removed and the root canals were prepared. Depending on the vehicle to be used for preparing calcium hydroxide pastes, six groups were made: Group I: Ca(OH)2 saline paste (control group), group II: Ca(OH)2 papaya latex paste, group III: Ca(OH)2 coconut water paste, group IV: Ca(OH)2 Ashwagandha (Withania somnifera) paste, group V: Ca(OH)2 Tulsi (Ocimum tenuiflorum) paste, and group VI: Ca(OH)2 garlic (Allium sativum) paste. After biomechanical preparation, calcium hydroxide herbal paste dressings were applied and sealed with resin-based cement. The teeth were placed in containers with deionized water, and the pH of the water was measured at regular intervals over 3, 24, 72, and 168 hours. Results We observed that all herbal pastes allowed the diffusion of ions, but pastes prepared with Ashwagandha and papaya latex showed more ion diffusion after 168 hours and marked increase in pH, depicting better support for calcium hydroxide action. Conclusion We conclude that Ashwagandha and papaya latex allow better diffusion of calcium hydroxide through den-tinal tubules, thus enhancing its action, and advise its use as a vehicle for placing intracanal medicament. How to cite this article Dausage P, Dhirawani RB, Marya J, Dhirawani V, Kumar V. A Comparative Study of Ion Diffusion from Calcium Hydroxide with Various Herbal Pastes through Dentin. Int J Clin Pediatr Dent 2017;10(1):41-44. PMID:28377654

  6. Efficacy of three methods for inserting calcium hydroxide-based paste in root canals

    PubMed Central

    Galvão, Thales; Camargo, Bernardo; Alves, Flávio

    2017-01-01

    Background To compare the quality of calcium hydroxide paste fillings performed by three different techniques. Material and Methods Sixty extracted maxillary central incisors, with previous root canal treatment, were decoronated and the gutta-percha was completely removed from the root canals. Subsequently, the canals were filled with a calcium hydroxide-based paste composed of calcium hydroxide, bismuth carbonate, and glycerin. The study samples were divided into the following three groups on the basis of three insertion techniques (n = 20, each): conventional technique using a hand instrument (MAN), rotary Lentulo spiral (LEN) technique, and a combined technique combining conventional hand files with sonic activation through the EndoActivator device (EA). The quality of fillings was evaluated radiographically by two examiners on the basis of the amount of voids and the apical limit. Results The canals filled with LEN or MAN had less void volume compared to the EA technique (P >0.01), with no significant differences between them. Considering the apical limits, the three tested techniques showed comparable results (P >0.05). Conclusions A combined approach utilizing hand files with sonic activation showed no enhancements over the LEN or MAN techniques on the quality of intracanal placement of calcium hydroxide paste. Key words:Calcium hydroxide placement, EndoActivator, Lentulo spirals, intracanal medication, root canal treatment. PMID:28638552

  7. Displaced calcium hydroxide paste causing inferior alveolar nerve paraesthesia: report of a case.

    PubMed

    Ahlgren, Fredrik K E K; Johannessen, Anne Christine; Hellem, Sølve

    2003-12-01

    A patient presented with an intraoral red, painful, and hard swelling in the lower right jaw. Radiographs showed a 2 x 1 cm area of radiopaque material surrounding the apex of the second premolar. The material, according to the patient's dentist, was calcium hydroxide paste used as a temporary dressing material in the root canal. The patient developed paraesthesia in her lower lip probably due to a neurotoxic effect caused by calcium hydroxide. The foreign material was surgically excavated from the spongious bone, directly adjacent to the nerve, and the patient later regained her sensation in the lip. A histopathological analysis revealed necrosis, deposits of foreign bodies, and inflammatory cells and foreign-body giant cells. This report illustrates the toxicity and adjacent clinical symptoms of calcium hydroxide paste when displaced into bone tissue close to the alveolar inferior nerve. It also demonstrates the benefits of removing such displaced material before symptoms progress.

  8. Intracanal placement of calcium hydroxide: a comparison of specially designed paste carrier technique with other techniques

    PubMed Central

    2013-01-01

    Background This study compared the effectiveness of a Specially Designed Paste Carrier technique with the Syringe-Spreader technique and the Syringe-Lentulo spiral technique in the intracanal placement of calcium hydroxide. Methods Three groups, each containing 15 single-rooted human anterior teeth were prepared using standardized Mtwo rotary instruments to a master apical file size 40 with 0.04 taper. Each group was filled with calcium hydroxide paste using: Syringe and #25 finger spreader (Group 1); Syringe and #4 rotary Lentulo spiral (Group 2), Specially Designed Paste Carrier (Group 3). Using pre-filling and post-filling radiographs in buccolingual and mesiodistal planes, the radiodensities at 1 mm, 3 mm, 5 mm, and 7 mm from the apical foramen were analyzed by ANOVA and Bonferroni post hoc tests. Results Overall, The Specially Designed Paste Carrier technique showed a statistically significantly higher mean radiodensity than the two other compared techniques. No significant difference was detected between the Syringe-Lentulo spiral and the Syringe-Spreader techniques. Conclusion The Specially Designed Paste Carrier technique was more effective than the Syringe-Spreader technique and the Syringe-Lentulo spiral technique in the intracanal placement of calcium hydroxide. PMID:24098931

  9. Diffusion of hydroxyl ions from calcium hydroxide and Aloe vera pastes.

    PubMed

    Batista, Victor Eduardo de Souza; Olian, Douglas Dáquila; Mori, Graziela Garrido

    2014-01-01

    This study evaluated the diffusion through the dentinal tubules of hydroxyl ions from different calcium hydroxide (CH) pastes containing Aloe vera. Sixty single-rooted bovine teeth were used. The tooth crowns were removed, the root canals were instrumented and the specimens were assigned to 4 groups (n=15) according to the intracanal medication: Group CH/S - CH powder and saline paste; Group CH/P - CH powder and propylene glycol paste; Group CH/A - calcium hydroxide powder and Aloe vera gel paste; Group CH/A/P - CH powder, Aloe vera powder and propylene glycol paste. After placement of the root canal dressings, the teeth were sealed coronally and apically with a two-step epoxy adhesive. The teeth were placed in identified flasks containing deionized water and stored in an oven with 100% humidity at 37 °C. After 3 h, 24 h, 72 h, 7 days, 15 days and 30 days, the deionized water in the flasks was collected and its pH was measured by a pH meter. The obtained data were subjected to statistical analysis at a significance level of 5%. The results demonstrated that all pastes provided diffusion of hydroxyl ions through the dentinal tubules. The combination of Aloe vera and CH (group CH/A) provided a constant release of calcium ions. Group CH/A/P showed the highest pH at 24 and 72 h. In conclusion, the experimental pastes containing Aloe vera were able to enable the diffusion of hydroxyl ions through the dentinal tubules.

  10. Antimicrobial Activity and Physicochemical Properties of Calcium Hydroxide Pastes Used as Intracanal Medication.

    PubMed

    Zancan, Rafaela Fernandes; Vivan, Rodrigo Ricci; Milanda Lopes, Marcelo Ribeiro; Weckwerth, Paulo Henrique; de Andrade, Flaviana Bombarda; Ponce, José Burgos; Duarte, Marco Antonio Hungaro

    2016-12-01

    The aim of the present study was to evaluate the pH, calcium release, solubility, and antimicrobial action against biofilms of calcium hydroxide + saline solution, Calen (SS White Artigos Dentários Ltd, Rio de Janeiro, Brazil) (CH/P), Calen camphorated paramonochlorophenol (CMCP) (CH/CMPC), and calcium hydroxide + chlorhexidine (CH/CHX) pastes. The pH of the pastes was determined with a calibrated pH meter placed in direct contact with each paste. The root canals of acrylic teeth (N = 10) were filled with the previously mentioned intracanal dressings and immersed in ultrapure water to measure hydroxyl (pH meter) and calcium ion release (atomic absorption spectrophotometer) at time intervals of 3, 7, 15, and 30 days. To assess solubility, the root canals of acrylic teeth (N = 10) were filled with the previously mentioned pastes and scanned by micro-computed tomographic imaging before (initial) and after 7, 15, and 30 days of immersion in ultrapure water. The solubility of each specimen was the difference between the initial and final volume scanning. For antimicrobial analysis, monospecies and dual-species biofilms were in vitro induced on dentin blocks (N = 20). Afterward, they were treated with the pastes for 7 days. Live/dead dye and a confocal microscope were used to measure the percentage of living cells. Data were statistically compared (P < .05). The highest OH(-) ion release values were found in 3 and 30 days. Ca(2+) releases were greater in CH/CMCP. CH/P and CH/CMCP showed a higher percentage of volume loss values. CH/CHX presented the greatest antimicrobial action. CH/P and CH/CMPC showed higher solubility values in the period analyzed. Seven days of contact may be insufficient for calcium hydroxide + saline solution, CH/P, and CH/CMCP pastes to kill bacterial cells in the biofilms studied. Chlorhexidine added to CH favored greater effectiveness against the previously mentioned bacterial biofilms. Copyright © 2016 American Association of

  11. Continued root-end growth and apexification using a calcium hydroxide and iodoform paste (Metapex®): three case reports.

    PubMed

    Sridhar, N; Tandon, Shobha

    2010-10-14

    The aim of these case reports is to present a treatment to promote root-end growth and apexification in nonvital immature permanent teeth in children. Three cases were presented where the calcium hydroxide and iodoform paste Metapex® was placed in the root canals of immature permanent teeth using disposable plastic tips. The teeth involved were evaluated radiographically at regular intervals for the first 12 months after placement of the paste. At the end of 12 months all the cases showed continued root growth and apical closure (apexification) with no evidence of periapical pathology. Conventional endodontic treatment was then performed. In all three of the clinical cases presented, a combination of calcium hydroxide and iodoform paste (Metapex®) was used and showed promising results in inducing root-end growth and closure after 12 months. In these three clinical cases, the calcium hydroxide and iodoform paste Metapex® (Meta Biomed Co. Ltd., South Korea) was found to induce apical closure when assessed radiographically. Over a period of 12 months all the cases showed continued root growth. The calcium hydroxide and iodoform paste Metapex® promoted continued root-end growth with apexification in the nonvital immature permanent teeth treated.

  12. In vitro evaluation of antimicrobial activity of different Gutta-percha points and calcium hydroxide pastes

    PubMed Central

    Jhamb, Ashu; Chaurasia, Vishwajit Rampratap; Masamatti, Vinay kumar S.; Agarwal, Jai Hans; Tiwari, Samarth; Nair, Divya

    2014-01-01

    Purpose: To evaluate the antimicrobial activity of different compositions of Gutta-percha points and calcium hydroxide (Ca(OH)2) pastes, used in endodontic therapy. Materials and Methods: The evaluated material consisted of Gutta-percha points containing Ca(OH)2, Gutta-percha points containing chlorhexidine (Chx), conventional Gutta-percha points and Ca(OH)2 pastes. Antimicrobial properties of Chx and CaOH paste are compared with CaOH points. Antimicrobial tests included three species of microorganisms: Escherichia coli (ATCC 25923), Staphylococcus aureus (ATCC 25922) Pseudomonas aeruginosa (ATCC BAA-427), the agar disc diffusion method was employed. The plates were kept at room temperature for 2 h for prediffusion and then incubated at 37°C for 24 h. Zones of inhibition were measured. Results and Conclusion: All microbial species used in the study were inhibited by the Gutta-percha points containing Chx and by the Ca(OH)2 pastes, no antimicrobial activity was observed for the other groups (conventional Gutta-percha and Ca(OH)2 group). PMID:25254192

  13. Comparison of ultrasonic irrigation and RinsEndo for the removal of calcium hydroxide and Ledermix paste from root canals.

    PubMed

    Rödig, Tina; Hirschleb, Manja; Zapf, Antonia; Hülsmann, Michael

    2011-12-01

    To compare the efficacy of ultrasonic irrigation and RinsEndo in removing calcium hydroxide and Ledermix paste from simulated root canal irregularities. The root canals of sixty extracted single-rooted teeth were prepared using FlexMaster rotary instruments to size 60, 0.02 taper. The roots were split longitudinally, and a standardized groove was prepared in the apical part of one segment. The teeth were randomly allocated into two groups (n = 30), according to the intracanal dressing. In the first group, grooves were filled with calcium hydroxide paste (Calxyl), whereas the grooves in the second group were filled with Ledermix paste. After reassembly, the root canals were completely filled with the respective medicament using a lentulo. The removal of medicament dressing was performed after 7 days with either passive ultrasonic irrigation or RinsEndo and 1% sodium hypochlorite for 3 min. The amount of remaining medicament was evaluated under a microscope with 30 × magnification using a four-grade scoring system. A regression analysis with P ≤ 0.05 was performed. Ledermix paste removal was significantly more effective than the removal of calcium hydroxide (P < 0.0001), whereas irrigation technique was not a significant factor (P = 0.3712). The percentages of complete removal of calcium hydroxide and Ledermix paste were 11.7% and 51.7%, respectively. None of the irrigation techniques was able to completely remove the intracanal medicaments from the apical part of the root canal. Irrespective of the irrigation technique, significantly less Ledermix paste was detected compared with calcium hydroxide. © 2011 International Endodontic Journal.

  14. Calcium hydroxide poisoning

    MedlinePlus

    These products contain calcium hydroxide: Cement Limewater Many industrial solvents and cleaners (hundreds to thousands of construction products, flooring strippers, brick cleaners, cement thickening products, and many ...

  15. Effect of the leaching of calcium hydroxide from cement paste on mechanical and physical properties

    SciTech Connect

    Carde, C.; Francois, R.

    1997-04-01

    This paper deals with the effect of the leaching process of cement based materials on their mechanical and physical properties. In order to characterize this effect, the authors have performed experiments on cement paste samples. The leaching process was achieved by the use of a 50% concentrate solution of ammonium nitrate. Both compression tests and water porosity tests were conducted on micro-cylinder samples (10, 12, 14 and 20 mm of diameter) because of the slow kinetics of degradation due to the leaching. The deterioration of the cement paste and the mortar exposed to the action of the ammonium nitrate was manifested by a peripheral zone of less resistance. This process induces mainly a total leaching of Ca(OH){sub 2} and a progressive decalcification of C-S-H which leads to a gradient of C/S ratio in the leaching zone. Both mechanical tests and water porosity tests show that there is a linear variation of the loss of strength and the increase in porosity in relation to the ratio of degraded area over total area of the sample A{sub d}/A{sub t}. It means that both compressive resistance and water porosity of the leaching zone are constant whatever the size of the degraded zone and then whatever the time of exposure to the chemical attack. So the authors could venture the hypothesis that the dissolution of calcium hydroxide is the essential parameter governing both decrease in strength and increase in porosity.

  16. Efficacy of different techniques for removal of calcium hydroxide-chlorhexidine paste from root canals.

    PubMed

    Camargo, Carlos Henrique Ribeiro; Leal, Flávia Martins; Silva, Gleyce Oliveira; de Oliveira, Tatiana Rocha; Madureira, Paloma Grasso; Camargo, Samira Esteves Afonso

    2016-01-01

    The purpose of this study was to evaluate the efficacy of different techniques for removal of combined calcium hydroxide [Ca(OH)2] and chlorhexidine paste from root canals. Fifty single-rooted human teeth were prepared by oscillatory and rotary systems and filled with a paste of Ca(OH)2 and 2% chlorhexidine gel. After incubation for 14 days, the specimens were divided into 5 groups (n = 10), and the medication was removed by 1 of 5 different procedures. In group 1 (control), removal procedures involved a master apical file, foraminal debridement, and 5 mL of saline solution applied with the NaviTip irrigation needle. Group 2 was treated the same as group 1, but in addition 0.5 mL of 17% ethylenediaminetetraacetic acid was used for 3 minutes. In group 3, ultrasonic agitation was performed for 1 minute. Group 4 was treated as group 2, but the NaviTip FX needle was used for irrigation. In group 5, a master apical file, foraminal debridement, and 3-minute application of 5 mL of citric acid were used. After the root-cleaning procedures, the crowns were removed at the cementoenamel junction, and the roots were split longitudinally into halves. The success of intracanal medicament removal was observed under stereoscopic microscope and scanning electron microscope. Remnants of Ca(OH)2 were found in all experimental groups, regardless of the removal technique used. There was no statistically significant difference in cleanliness in the apical third of the root canal among groups 1, 2, and 3. Group 4 showed the best and group 5 the worst results with statistically significant differences. Overall, the NaviTip FX irrigation needle technique was more efficient in removing a Ca(OH)2-chlorhexidine paste from the root canal.

  17. The Ability of Triple Antibiotic Paste and Calcium Hydroxide in Disinfection of Dentinal Tubules

    PubMed Central

    Adl, Alireza; Hamedi, Sabie; Sedigh Shams, Mahdi; Motamedifar, Mohamad; Sobhnamayan, Fereshte

    2014-01-01

    Introduction: The purpose of this in vitro study was to compare the ability of triple antibiotic paste (TAP) to calcium hydroxide (CH) in disinfecting dentinal tubules. Material and Methods: Sixty root blocks were obtained from extracted single-rooted human teeth. The root canals were enlarged with Gates-Glidden drills up to size 3 and were contaminated with Enterococcus. faecalis (E. faecalis), and then left for 21 days. The contaminated blocks were treated with saline (as negative control), CH or TAP. Dentin debris was obtained at the end of first and 7th days, using Gates-Glidden drills sizes 4 and 5 from two different depths of 100 and 200 µm. The vital bacterial load was assessed by counting the number of colony forming units (CFUs). The data was analyzed with the Kruskal-Wallis H and Dunn Post-Hoc tests. The Wilcoxon Signed Ranks test was used to check for differences in bacterial growth at both depths (P<0.05). Results: In comparison with CH, the TAP significantly decreased the number of CFUs in both depths and time intervals (P<0.001), while the CH group showed a moderate antibacterial effect. Conclusion: TAP is more effective in disinfecting the canal against E. faecalis compared to CH. PMID:24688581

  18. Antimicrobial and chemical study of MTA, Portland cement, calcium hydroxide paste, Sealapex and Dycal.

    PubMed

    Estrela, C; Bammann, L L; Estrela, C R; Silva, R S; Pécora, J D

    2000-01-01

    The objective of this study was to investigate the antimicrobial action of mineral trioxide aggregate (MTA), Portland cement, calcium hydroxide paste (CHP), Sealapex and Dycal. The chemical elements of MTA and two Portland cements were also analyzed. Four standard bacterial strains: Staphylococcus aureus (ATCC 6538), Enterococcus faecalis (ATCC 29212), Pseudomonas aeruginosa (ATCC 27853), Bacillus subtilis (ATCC 6633), one wild fungus, Candida albicans (ICB/USP-562), and one mixture of these were used. Thirty Petri plates with 20 ml of BHI agar were inoculated with 0.1 ml of the experimental suspensions. Three cavities, each one measuring 4 mm in depth and 4 mm in diameter, were made in each agar plate using a copper coil and then completely filled with the product to be tested. The plates were pre-incubated for 1 h at environmental temperature followed by incubation at 37 degrees C for 48 h. The diameters of the zones of microbial inhibition were then measured. Samples from diffusion and inhibition halos were extracted from each plate and immersed in 7 ml BHI broth and incubated at 37 degrees C for 48 h. Analyses of chemical elements present in MTA and in two samples of Portland cement were performed with a fluorescence spectrometer Rx. The results showed that the antimicrobial activity of CHP was superior to those of MTA, Portland cement, Sealapex and Dycal, for all microorganisms tested, presenting inhibition zones of 6-9.5 mm and diffusion zones of 10-18 mm. MTA, Portland cement, and Sealapex presented only diffusion zones and among these, Sealapex produced the largest zone. Dycal did not show inhibition or diffusion zones. Portland cements contain the same chemical elements as MTA except that MTA also contains bismuth.

  19. Leaching of both calcium hydroxide and C-S-H from cement paste: Modeling the mechanical behavior

    SciTech Connect

    Carde, C.; Torrenti, J.M.; Francois, R.

    1996-08-01

    This paper deals with the effect of the leaching process of cement based materials on their mechanical properties. This process induces mainly a total leaching of Ca(OH){sub 2} and a progressive decalcification of C-S-H which leads to a gradient of C/S ratio in the leaching zone. In a previous work, the authors venture the hypothesis that the dissolution of calcium hydroxide was the essential parameter governing both decrease in strength and increase in porosity in the case of a paste sample made with an OPC cement which leads to a 20% content of calcium. In order to quantify the effect of the decrease of C/S ratio in C-S-H, the authors have performed experiments on paste samples with the admixture of silica fume to reduce the content of calcium hydroxide and thus emphasize the effect of C/S ratio decrease of the C-S-H. The leaching process was achieved by the use of a 50% concentrate solution of ammonium nitrate. Compression tests were conducted on micro-cylinder samples (10, 12, 14, 20 and 30 mm of diameter) because of the slow kinetics of degradation due to the leaching. The deterioration of the cement paste and the mortar exposed to the action of the ammonium nitrate was indicated by a peripheral zone of less resistance. The experimental results allow the modeling of the mechanical behavior of cement pastes in relation to the ratio of degraded area over total area of the sample A{sub d}/A{sub t}. The model thus defined allows separation of the effect of calcium hydroxide leaching and C-S-H leaching, and shows the importance of the first one. The current research program tries to characterize the deterioration of the mechanical properties of the concrete surrounding radioactive wastes, due to the water flow during storage.

  20. Effect of ultrasonic streaming on intra-dentinal disinfection and penetration of calcium hydroxide paste in endodontic treatment

    PubMed Central

    ARIAS, Marcela Paola Castro; MALIZA, Amanda Garcia Alves; MIDENA, Raquel Zanin; GRAEFF, Márcia Sirlene Zardin; DUARTE, Marco Antonio Húngaro; de ANDRADE, Flaviana Bombarda

    2016-01-01

    ABSTRACT Objective The antimicrobial effect of ultrasonic agitation of calcium hydroxide (CH) pastes in infected bovine dentin and their penetrability were evaluated using confocal laser scanning microscopy (CLSM) and microbiological culture. Material and Methods Fifty-two bovine teeth were infected with Enterococcus faecalis using a new contamination protocol; then they received CH paste and were divided into groups with or without ultrasound. Ultrasonic agitation was conducted for 1 min with a plain point insert. After 15 d, the CLSM analyzed the viable and dead bacteria with Live and Dead assay. The dentinal wall debris was collected by burs, and the colony forming units (CFU/mL) were counted. The penetrability of the paste inside dentinal tubules was tested using the B-rodamine dye. Results The calcium hydroxide paste showed better results with the use of ultrasonic agitation (p<0.05). Conclusion The ultrasonic agitation of CH paste increased its antimicrobial action and was responsible for intradentinal penetration with the fulfilment of the tubules. PMID:28076462

  1. Antibiofilm efficacy of photoactivated curcumin, triple and double antibiotic paste, 2% chlorhexidine and calcium hydroxide against Enterococcus fecalis in vitro

    PubMed Central

    Devaraj, Sharmila; Jagannathan, Nithya; Neelakantan, Prasanna

    2016-01-01

    Root canal disinfection is one of the most important factors governing success of root canal treatment, especially when regenerative strategies are used. This study evaluated the efficacy of 5 intracanal medicaments against mature biofilms of Enterococcus fecalis in vitro: Light activated curcumin, triple antibiotic paste (TAP), double antibiotic paste (DAP), chlorhexidine, calcium hydroxide. Untreated teeth with biofilms served as controls. Confocal microscopy was used to analyse the biofilm mass and percentage of live/dead bacteria within the root canal as well as dentinal tubules. Dentinal shavings obtained from the root canal walls (at 200 and 400 microns depth) were used to quantify the colony forming units/mL. The results showed that light activated curcumin and triple antibiotic paste brought about complete disruption of the biofilm structure (P < 0.05) while chlorhexidine and calcium hydroxide were not significantly different from the control (P > 0.05). Light activated curcumin brought about the highest percentage of dead cells at both depths, but this was not significantly different from triple antibiotic paste (P > 0.05). Curcumin, TAP and DAP brought about a significant reduction of CFU/mL at both depths compared to the control and other groups (P < 0.05). Light activated curcumin brought about a 7 log reduction of bacteria at both depths. PMID:27097667

  2. Antibiofilm efficacy of photoactivated curcumin, triple and double antibiotic paste, 2% chlorhexidine and calcium hydroxide against Enterococcus fecalis in vitro.

    PubMed

    Devaraj, Sharmila; Jagannathan, Nithya; Neelakantan, Prasanna

    2016-04-21

    Root canal disinfection is one of the most important factors governing success of root canal treatment, especially when regenerative strategies are used. This study evaluated the efficacy of 5 intracanal medicaments against mature biofilms of Enterococcus fecalis in vitro: Light activated curcumin, triple antibiotic paste (TAP), double antibiotic paste (DAP), chlorhexidine, calcium hydroxide. Untreated teeth with biofilms served as controls. Confocal microscopy was used to analyse the biofilm mass and percentage of live/dead bacteria within the root canal as well as dentinal tubules. Dentinal shavings obtained from the root canal walls (at 200 and 400 microns depth) were used to quantify the colony forming units/mL. The results showed that light activated curcumin and triple antibiotic paste brought about complete disruption of the biofilm structure (P < 0.05) while chlorhexidine and calcium hydroxide were not significantly different from the control (P > 0.05). Light activated curcumin brought about the highest percentage of dead cells at both depths, but this was not significantly different from triple antibiotic paste (P > 0.05). Curcumin, TAP and DAP brought about a significant reduction of CFU/mL at both depths compared to the control and other groups (P < 0.05). Light activated curcumin brought about a 7 log reduction of bacteria at both depths.

  3. Analysis of the reaction of subcutaneous tissues in rats and the antimicrobial activity of calcium hydroxide paste used in association with different substances.

    PubMed

    Midena, Raquel Zanin; Garcia, Roberto Brandão; Cavenago, Bruno Cavalini; Marciano, Marina Angélica; Minotti, Paloma Gagliardi; Ordinola-Zapata, Ronald; Weckwerth, Paulo Henrique; Andrade, Flaviana Bombarda de; Duarte, Marco Antonio Hungaro

    2015-10-01

    The aim of this study was to evaluate the subcutaneous tissue response in rats and the antimicrobial activity of intracanal calcium hydroxide dressings mixed with different substances against E. faecalis. Fifty four rats were divided into three experimental groups according to the vehicle in the calcium hydroxide treatment: 0.4% chlorohexidine in propylene glycol (PG),Casearia sylvestris Sw in PG and calcium hydroxide+PG (control group). The pastes were placed into polyethylene tubes and implanted into the subcutaneous tissue. After 7, 14 and 30 days, the samples were processed and histologically evaluated (hematoxylin and eosin). The tissue surface in contact with the material was analyzed, and the quantitative analysis determined the volume density occupied by the inflammatory infiltrate (giant cells, polymorphonuclear cells and mononuclear cells), fibroblasts, collagen fibers and blood vessels. For the antimicrobial analysis, 20 dentin blocks infected with E. faecalis were treated with calcium hydroxide pastes in different vehicles; 0.4% chlorhexidine in PG, PG, extract from Casearia sylvestris Sw in PG and a positive control (infection and without medication) for 7 days. The efficiency of the pastes was evaluated by the live/dead technique and confocal microscopy. The results showed that 0.4% chlorhexidine induced a higher inflammatory response than the other groups. The Casearia sylvestris Sw extract showed satisfactory results in relation to the intensity of the inflammatory response. In the microbiological test, there were no statistical differences between the evaluated intracanal dressings and the percentage of bacterial viability was between 33 and 42%. The control group showed an 86% viability. Antimicrobial components such as chlorhexidine or Casearia sylvestris Sw did not improve the antimicrobial activity against E. faecalis in comparison to the calcium hydroxide+PG treatment. In addition, the incorporation of chlorhexidine in the calcium hydroxide

  4. Analysis of the reaction of subcutaneous tissues in rats and the antimicrobial activity of calcium hydroxide paste used in association with different substances

    PubMed Central

    MIDENA, Raquel Zanin; GARCIA, Roberto Brandão; CAVENAGO, Bruno Cavalini; MARCIANO, Marina Angélica; MINOTTI, Paloma Gagliardi; ORDINOLA-ZAPATA, Ronald; WECKWERTH, Paulo Henrique; de ANDRADE, Flaviana Bombarda; DUARTE, Marco Antonio Hungaro

    2015-01-01

    The aim of this study was to evaluate the subcutaneous tissue response in rats and the antimicrobial activity of intracanal calcium hydroxide dressings mixed with different substances against E. faecalis. Fifty four rats were divided into three experimental groups according to the vehicle in the calcium hydroxide treatment: 0.4% chlorohexidine in propylene glycol (PG), Casearia sylvestris Sw in PG and calcium hydroxide+PG (control group). The pastes were placed into polyethylene tubes and implanted into the subcutaneous tissue. After 7, 14 and 30 days, the samples were processed and histologically evaluated (hematoxylin and eosin). The tissue surface in contact with the material was analyzed, and the quantitative analysis determined the volume density occupied by the inflammatory infiltrate (giant cells, polymorphonuclear cells and mononuclear cells), fibroblasts, collagen fibers and blood vessels. For the antimicrobial analysis, 20 dentin blocks infected with E. faecalis were treated with calcium hydroxide pastes in different vehicles; 0.4% chlorhexidine in PG, PG, extract from Casearia sylvestris Sw in PG and a positive control (infection and without medication) for 7 days. The efficiency of the pastes was evaluated by the live/dead technique and confocal microscopy. The results showed that 0.4% chlorhexidine induced a higher inflammatory response than the other groups. The Casearia sylvestris Sw extract showed satisfactory results in relation to the intensity of the inflammatory response. In the microbiological test, there were no statistical differences between the evaluated intracanal dressings and the percentage of bacterial viability was between 33 and 42%. The control group showed an 86% viability. Antimicrobial components such as chlorhexidine or Casearia sylvestris Sw did not improve the antimicrobial activity against E. faecalis in comparison to the calcium hydroxide+PG treatment. In addition, the incorporation of chlorhexidine in the calcium hydroxide

  5. [An experimental study on mineral triozide aggregate and calcium hydroxide-based paste applied to direct pulp capping in rat].

    PubMed

    Zhao, Yan; Jin, Asari; Gao, Ping; Mitsuko, Inoue

    2013-08-01

    To evaluate the volume change of rat root following direct pulp capping with mineral triozide aggregate(MTA) and calcium hydroxide-based paste (Vitapex) . Sixty-four female, 1-month-old Wistar rats were randomly divided into 4 groups, MTA group, Vitapex group, model group and control group, 16 rats in each group. The right maxillary first molar was taken as experimental tooth and control tooth. The exposed pulp was capped separately with MTA and calcium hydroxide after the pulp had been exposed mechanically, while nothing done to the control group. Using micro-CT and three-dimensional reconstruction techniques, the volume change of rat root was evaluated at 1, 2, 4 weeks and 6 weeks after direct pulp capping. The data were analyzed by an way ANOVA analysis followed by a LSD-t test. The root volume in the MTA group[(1.08 ± 0.07), (1.32 ± 0.18) mm(3)] was significantly smaller than that in the Vitapex group[(1.28 ± 0.16), (1.59 ± 0.18) mm(3)] at 2 and 4 weeks after operation (P < 0.05) . At the sixth week , there was no significant difference between the MTA group [(1.36 ± 0.03) mm(3)] and the Vitapex group[(1.61 ± 0.31) mm(3)] (P > 0.05) . The root volume in the MTA group and Vitapex group was significantly larger than that in the model group [(0.87 ± 0.09), (1.01 ± 0.17) , (1.02 ± 0.25) mm(3)] from the second to sixth week after operation (P < 0.05) . MTA and Vitapex can effectively promote root formation and growth and can be used as biological pulp-capping material.

  6. Antimicrobial and Cytotoxic Activity of Cinnamomum zeylanicum, Calcium Hydroxide, and Triple Antibiotic Paste as Root Canal Dressing Materials.

    PubMed

    Abbaszadegan, Abbas; Dadolahi, Sahar; Gholami, Ahmad; Moein, Mahmoud Reza; Hamedani, Shahram; Ghasemi, Younes; Abbott, Paul Vincent

    2016-02-01

    The aim of this article was (i) to define the chemical constituents of Cinnamomum zeylanicum essential oil (CEO), (ii) to compare the antimicrobial activity of CEO with triple antibiotic paste (TAP) and calcium hydroxide [Ca(OH)2] on planktonic and biofilm Enterococcus faecalis; and (iii) to compare the cytotoxicity of these medicaments on L929 fibroblasts. Gas chromatography-mass spectrometry was used to define the constituents of CEO. Zone of inhibition, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and time-kill tests were performed. Further, 108 human teeth were infected with E. faecalis and treated with the medicaments for 1, 7, and 14 days. Cytotoxicity was assessed by exposing L929 fibroblasts to the medicaments. Cinnamaldehyde was the main component of CEO. Triple antibiotic paste had the greatest zone of inhibition and the smallest MIC and MBC. Triple antibiotic paste and CEO eradicated planktonic E. faecalis after 4 and 24 hours, while Ca(OH)2 failed to achieve 100% killing after 24 hours. Cinnamomum zeylanicum essential oil and TAP eradicated biofilm E. faecalis after 7 and 14 days, but Ca(OH)2 could not eliminate E. faecalis after 14 days. Cinnamomum zeylanicum essential oil was the most biocompatible medicament. Cinnamomum zeylanicum essential oil is an efficient antibacterial agent against planktonic and biofilm E. faecalis and it was cytocompatible to L929 fibroblasts. Therefore, CEO has the potential to be used as an antimicrobial agent in root canal treatment.

  7. Microscopic cleanliness evaluation of the apical root canal after using calcium hydroxide mixed with chlorhexidine, propylene glycol, or antibiotic paste.

    PubMed

    da Silva, Juliana M; Andrade Junior, Carlos V; Zaia, Alexandre A; Pessoa, Oscar F

    2011-02-01

    This study evaluated cleaning of the dentinal wall after removal of different calcium hydroxide pastes. Sixty-eight single-rooted teeth were prepared using the step-back technique and randomly divided into 4 groups according to medication used: Ca(OH)2 with 0.2% chlorhexidine solution (Group 1), Ca(OH)2 with propylene glycol (Group 2), Ca(OH)2 with antibiotic paste (ciprofloxacin, metronidazole) and distilled water (Group 3), and Ca(OH)2 with antibiotic paste and propylene glycol (Group 4). The samples were stored at 37 °C and 100% relative humidity for 21 days. The medicaments were removed using 5 mL 1% NaOCl, instrumentation with master apical file, 5 mL 1% NaOCl, patency with the K-file #10, ultrasonic instrumentation, and 10 mL 17% EDTA-T. The specimens were analyzed using scanning electron microscopy and chemical analysis. The Kruskal-Wallis (α = 5%) test showed that were no differences between the experimental groups when comparing Ca(OH)2 removal (P = .0951). The chi-square test (α = 5%) indicated a predominance of Ca(OH)2 obstructing dental tubules in all groups. On the basis of the methodology applied, it was concluded that the apical dentine surface remained equally covered by Ca(OH)2, regardless of the vehicle used.

  8. Assessment of the Antibacterial Activity of Calcium Hydroxide Combined with Chlorhexidine Paste and Other Intracanal Medications against Bacterial Pathogens

    PubMed Central

    de Magalhães Silveira, Cláudia Fernandes; Cunha, Rodrigo Sanches; Fontana, Carlos Eduardo; de Martin, Alexandre Sigrist; de Almeida Gomes, Brenda Paula Figueiredo; Motta, Rogério Heládio Lopes; da Silveira Bueno, Carlos Eduardo

    2011-01-01

    Objectives: The purpose of this study was to assess the in vitro antibacterial activity of four formulations of calcium hydroxide [Ca(OH)2] pastes against Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa and Streptococcus mutans. Methods: A broth dilution test was performed, and the lengths of time for different pastes to kill the microbial cells were recorded and statistically analyzed. The following medications were assessed: Group I – Ca(OH)2 + 2.0% chlorhexidine (CHX) gel; Group II – Ca(OH)2 + camphorated paramonochlorophenol (CMCP) and propylene glycol; Group III – Ca(OH)2 + propylene glycol; Group IV – Ca(OH)2 + saline. Results: The results showed that E. faecalis was the most resistant microorganism. Groups II and III eliminated all the microbial cells in 15 seconds. Group I took 45 seconds to eliminate E. faecalis. Conclusions: Under the conditions of this study, it was concluded that all the intracanal medications tested showed antibacterial activity. However, the association of Ca(OH)2 and PMCC or Ca(OH)2 and propylene glycol showed a better performance, since Groups II and III took a shorter length of time than the other groups to eliminate S. aureus and E. faecalis. PMID:21311611

  9. Evaluation of hydroxyl ion diffusion in dentin and injectable forms and a simple powder-water calcium hydroxide paste: an in vitro study.

    PubMed

    Eftekhar, Behrooz; Moghimipour, Eskandar; Eini, Ebrahim; Jafarzadeh, Mansour; Behrooz, Narges

    2014-08-01

    Intra canal medicaments are used to reduce the number of bacteria and reinfection in endodontic procedures. Calcium Hydroxide was introduced to endodontics by Herman as an intracanal antimicrobial agent. The aim of this study was to present an injectable formulation of calcium hydroxide then compare the final pH of this new formulation with Metapaste and evaluate the effect of a mixture of Calcium Hydroxide powder with water on human extracted teeth. A total of 49 extracted human single-canal roots without caries and visible microcracks were included in this study. The teeth were decoronated and length of teeth was measured 1 mm anatomic apex. The canals were prepared using step-back technique. A cavity was created in the middle third of the buccal surface of all roots. The teeth were randomly divided into five groups: Group A (n = 15): In this group the root canals were filled with a mixture of calcium hydroxide powder and distilled water. Group B (n = 15): Included roots that were filled with Metapaste. Group C (n = 15): Root canals of this group were filled with new formulation of calcium hydroxide paste. Group D (negative control, n = 2): Included roots that were filled with a mixture of calcium hydroxide powder and distilled water. Group E (positive control, n = 2): Root canals of this group were filled with a mixture of calcium hydroxide powder and distilled water. Each tooth was immersed in a separate closed container with 4 mL saline for 2 weeks, pH of liquids were measured with an electrical pH meter after 7 and 14 days. The SPSS software (version 13) was used for data analysis. Analysis of variance (ANOVA) and Tukey tests were used for the statistical evaluation of results. There was no significant difference at 7th day between the groups (P = 0.17) but at 14th day, a significant difference was observed between the groups (P = 0.04). The new formulation of calcium hydroxide with methylcellulose base has slower ionic dissolution, more durability and

  10. Evaluation of Hydroxyl Ion Diffusion in Dentin and Injectable Forms and a Simple Powder-Water Calcium Hydroxide Paste: An in Vitro Study

    PubMed Central

    Eftekhar, Behrooz; Moghimipour, Eskandar; Eini, Ebrahim; Jafarzadeh, Mansour; Behrooz, Narges

    2014-01-01

    Background: Intra canal medicaments are used to reduce the number of bacteria and reinfection in endodontic procedures. Calcium Hydroxide was introduced to endodontics by Herman as an intracanal antimicrobial agent. Objectives: The aim of this study was to present an injectable formulation of calcium hydroxide then compare the final pH of this new formulation with Metapaste and evaluate the effect of a mixture of Calcium Hydroxide powder with water on human extracted teeth. Patients and Methods: A total of 49 extracted human single-canal roots without caries and visible microcracks were included in this study. The teeth were decoronated and length of teeth was measured 1 mm anatomic apex. The canals were prepared using step-back technique. A cavity was created in the middle third of the buccal surface of all roots. The teeth were randomly divided into five groups: Group A (n = 15): In this group the root canals were filled with a mixture of calcium hydroxide powder and distilled water. Group B (n = 15): Included roots that were filled with Metapaste. Group C (n = 15): Root canals of this group were filled with new formulation of calcium hydroxide paste. Group D (negative control, n = 2): Included roots that were filled with a mixture of calcium hydroxide powder and distilled water. Group E (positive control, n = 2): Root canals of this group were filled with a mixture of calcium hydroxide powder and distilled water. Each tooth was immersed in a separate closed container with 4 mL saline for 2 weeks, pH of liquids were measured with an electrical pH meter after 7 and 14 days. The SPSS software (version 13) was used for data analysis. Analysis of variance (ANOVA) and Tukey tests were used for the statistical evaluation of results. Results: There was no significant difference at 7th day between the groups (P = 0.17) but at 14th day, a significant difference was observed between the groups (P = 0.04). Conclusions: The new formulation of calcium hydroxide with

  11. The XP-Endo Finisher for the removal of calcium hydroxide paste from root canals and from the apical third.

    PubMed

    Hamdan, Rami; Michetti, Jérôme; Pinchon, Déborah; Diemer, Franck; Georgelin-Gurgel, Marie

    2017-07-01

    The aim was to compare the efficacy of the passive ultrasonic irrigation PUI and the Xp-endo Finisher (FKG-Dentaire, La-Chaux-de-Fonds, Switzerland) in removing the calcium hydroxide paste from root canals and from the apical third. Sixty-eight root canals of single-rooted teeth were shaped using the BT-Race files (FKG-Dentaire, La-Chaux-de-Fonds, Switzerland). Ca(OH)2 was placed in all samples except for the negative control group (n=4). Remaining teeth were randomly divided into three groups: G1-Xp (n=30), G2-PUI (n=30) and the positive control group (n=4). Removal procedure consisted of three repeated one-minute-cycles. Samples were split longitudinally, photos of halves were taken at X6.4 magnification and were analyzed using the ImageJ-Software (The National Institutes of Health NIH, Bethesda, Maryland, USA) to calculate the percentage of surfaces with residual Ca(OH)2; the results were compared using the Wilcoxon-Mann Whitney test. Photos of the apical thirds were taken at X16 and X40 magnifications and were scored by two examiners from (0) to (4). Scores of the apical third were compared using the Fisher test. The Xp-endo Finisher removed completely the Ca(OH)2 dressing from four teeth (13.33%) whereas the PUI in one tooth (3.33%). The mean values of the remaining Ca(OH)2 were (2.1%, 3.6%) respectively and the difference was not significant (p= 0.195). Both examiners found the Xp-endo Finisher more efficient in the apical third and the difference was significant; p= (0.025, 0.047) respectively. The Xp-endo Finisher showed a superiority over the PUI in removing the Ca(OH)2 from the apical third after 3 minutes of activation. Key words:Calcium hydroxide removal, Passive ultrasonic irrigation, Xp-endo Finisher.

  12. Effect of calcium hydroxide and triple antibiotic paste as intracanal medicaments on the incidence of inter-appointment flare-up in diabetic patients: An in vivo study

    PubMed Central

    Pai, Swathi; Vivekananda Pai, A. R.; Thomas, Manuel S.; Bhat, Vishal

    2014-01-01

    Aim: To evaluate and compare the effect of antibacterial intracanal medicaments on inter-appointment flare-up in diabetic patients. Materials and Methods: Fifty diabetic patients requiring root canal treatment were assigned into groups I, II, and III. In group I, no intracanal medicament was placed. In groups II and III, calcium hydroxide and triple antibiotic pastes were placed as intracanal medicaments, respectively. Patients were instructed to record their pain on days 1, 2, 3, 7, and 14. Inter-appointment flare-up was evaluated using verbal rating scale (VRS). Results: Overall incidence of inter-appointment flare-up among diabetic patients was found to be 16%. In group I, 50% of the patients and in group II, 15% of the patients developed inter-appointment flare-up. However, no patients in group III developed inter-appointment flare-up. The comparison of these results was found to be statistically significant (P = 0.002; χ2 = 12.426). However, with respect to intergroup comparison, only the difference between groups I and III was found to be statistically significant (P = 0.002; χ2 = 12.00). Conclusions: Calcium hydroxide and triple antibiotic paste are effective for managing inter-appointment flare-ups in diabetic patients. Triple antibiotic paste is more effective than calcium hydroxide in preventing the occurrence of flare-up in diabetic patients. PMID:24944440

  13. Microbial evaluation of traumatized teeth treated with triple antibiotic paste or calcium hydroxide with 2% chlorhexidine gel in pulp revascularization.

    PubMed

    Nagata, Juliana Y; Soares, Adriana J; Souza-Filho, Francisco J; Zaia, Alexandre A; Ferraz, Caio C R; Almeida, José F A; Gomes, Brenda P F A

    2014-06-01

    Revascularization outcome depends on microbial elimination because apical repair will not happen in the presence of infected tissues. This study evaluated the microbial composition of traumatized immature teeth and assessed their reduction during different stages of the revascularization procedures performed with 2 intracanal medicaments. Fifteen patients (7-17 years old) with immature teeth were submitted to the revascularization procedures; they were divided into 2 groups according to the intracanal medicament used: TAP group (n = 7), medicated with a triple antibiotic paste, and CHP group (n = 8), dressed with calcium hydroxide + 2% chlorhexidine gel. Samples were taken before any treatment (S1), after irrigation with 6% NaOCl (S2), after irrigation with 2% chlorhexidine (S3), after intracanal dressing (S4), and after 17% EDTA irrigation (S5). Cultivable bacteria recovered from the 5 stages were counted and identified by means of polymerase chain reaction assay (16S rRNA). Both groups had colony-forming unit counts significantly reduced after S2 (P < .05); however, no significant difference was found between the irrigants (S2 and S3, P = .99). No difference in bacteria counts was found between the intracanal medicaments used (P = .95). The most prevalent bacteria detected were Actinomyces naeslundii (66.67%), followed by Porphyromonas endodontalis, Parvimonas micra, and Fusobacterium nucleatum, which were detected in 33.34% of the root canals. An average of 2.13 species per canal was found, and no statistical correlation was observed between bacterial species and clinical/radiographic features. The microbial profile of infected immature teeth is similar to that of primarily infected permanent teeth. The greatest bacterial reduction was promoted by the irrigation solutions. The revascularization protocols that used the tested intracanal medicaments were efficient in reducing viable bacteria in necrotic immature teeth. Copyright © 2014 American Association of

  14. Predictive Mechanical Characterization of Macro-Molecular Material Chemistry Structures of Cement Paste at Nano Scale - Two-phase Macro-Molecular Structures of Calcium Silicate Hydrate, Tri-Calcium Silicate, Di-Calcium Silicate and Calcium Hydroxide

    NASA Astrophysics Data System (ADS)

    Padilla Espinosa, Ingrid Marcela

    Concrete is a hierarchical composite material with a random structure over a wide range of length scales. At submicron length scale the main component of concrete is cement paste, formed by the reaction of Portland cement clinkers and water. Cement paste acts as a binding matrix for the other components and is responsible for the strength of concrete. Cement paste microstructure contains voids, hydrated and unhydrated cement phases. The main crystalline phases of unhydrated cement are tri-calcium silicate (C3S) and di-calcium silicate (C2S), and of hydrated cement are calcium silicate hydrate (CSH) and calcium hydroxide (CH). Although efforts have been made to comprehend the chemical and physical nature of cement paste, studies at molecular level have primarily been focused on individual components. Present research focuses on the development of a method to model, at molecular level, and analysis of the two-phase combination of hydrated and unhydrated phases of cement paste as macromolecular systems. Computational molecular modeling could help in understanding the influence of the phase interactions on the material properties, and mechanical performance of cement paste. Present work also strives to create a framework for molecular level models suitable for potential better comparisons with low length scale experimental methods, in which the sizes of the samples involve the mixture of different hydrated and unhydrated crystalline phases of cement paste. Two approaches based on two-phase cement paste macromolecular structures, one involving admixed molecular phases, and the second involving cluster of two molecular phases are investigated. The mechanical properties of two-phase macromolecular systems of cement paste consisting of key hydrated phase CSH and unhydrated phases C3S or C2S, as well as CSH with the second hydrated phase CH were calculated. It was found that these cement paste two-phase macromolecular systems predicted an isotropic material behavior. Also

  15. Efficacy of Triple Antibiotic Paste, Moxifloxacin, Calcium Hydroxide And 2% Chlorhexidine Gel In Elimination of E. Faecalis: An In vitro Study

    PubMed Central

    Sekhar, K.S; Gupta, Pankaj; Tejolatha, Bellam; Gupta, Anjali; Kashyap, Shruti; Desai, Veena; Farista, Shanin

    2017-01-01

    Introduction Root canal treatment is incomplete without usage of intra canal medicaments. They help in the reduction of bacterial count and its by-products, making canals clean and decreasing postoperative pains. Aim The aim of this study was to evaluate and compare the antimicrobial activity of triple antibiotic paste, Moxifloxacin, calcium hydroxide and 2% Chlorhexidine (CHX) gel in elimination of Enterococcous faecalis (E. faecalis). Materials and Methods Seventy-five root blocks were obtained from extracted single rooted human teeth. The canal diameter was increased using Gates- Glidden drill up to size 3 and then contaminated with E. faecalis for 21 days. The contaminated samples were then divided into following 5 groups. Group 1: Saline (negative group), Group 2: Calcium hydroxide Ca(OH)2, Group 3: 2% CHX gel, Group 4: Triple Antibiotic Paste (TAP) (50 μg – metronidazole of 400 mg, 50 μg – minocycline of 100 mg, 50 μg – ciprofloxacin of 100 mg) and Group 5: Moxifloxacin (50 μg – moxifloxacin of 400 mg). Dentin debris was obtained at the end of first, 7th, and 10th day using Gates Glidden drill sizes 4 and 5. The bacterial load was assessed by counting the number of Colony Forming Units (CFUs). The data were analyzed with the ANOVA and Post-Hoc tests to assess the differences in antibacterial efficacy between groups (p=<0.001). Results A 2% CHX gel alone completely inhibited the growth of E. faecalis after one, seven and 10 days. The 2% CHX gel was the most effective medicament against E. faecalis, as it showed significant differences with normal saline, calcium hydroxide, Moxifloxacin or triple antibiotic paste at all time intervals. The triple antibiotic paste group showed a moderate antibacterial effect as its difference with all group was significantly better at all days. Moxifloxacin was more effective than calcium hydroxide on 7th and 10th day. Conclusion Best antimicrobial efficacy was shown by 2% CHX gel. Moxifloxacin was equally efficient

  16. 21 CFR 582.1205 - Calcium hydroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Additives § 582.1205 Calcium hydroxide. (a) Product. Calcium hydroxide. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or feeding...

  17. Effects of the association between a calcium hydroxide paste and 0.4% chlorhexidine on the development of the osteogenic phenotype in vitro.

    PubMed

    da Silva, Raquel Assed Bezerra; Leonardo, Mário Roberto; da Silva, Léa Assed Bezerra; de Castro, Larissa Moreira Spinola; Rosa, Adalberto Luiz; de Oliveira, Paulo Tambasco

    2008-12-01

    The present study aimed to evaluate whether the association between a calcium hydroxide paste (Calen paste) and 0.4% chlorhexidine (CHX) affects the development of the osteogenic phenotype in vitro. With rat calvarial osteogenic cell cultures, the following parameters were assayed: cell morphology and viability, alkaline phosphatase activity, total protein content, bone sialoprotein immunolocalization, and mineralized nodule formation. Comparisons were carried out by using the nonparametric Kruskal-Wallis test (level of significance, 5%). The results showed that the association between Calen paste and 0.4% CHX did not affect the development of the osteogenic phenotype. No significant changes were observed in terms of cell shape, cell viability, alkaline phosphatase activity, and the total amount of bone-like nodule formation among control, Calen, or Calen + CHX groups. The strategy to combine Ca(OH)(2) and CHX to promote a desirable synergistic antibacterial effect during endodontic treatment in vivo might not significantly affect osteoblastic cell biology.

  18. EFFECTIVENESS OF NaOCl ALONE OR IN COMBINATION WITH EDTA ON THE DIFFUSION OF HYDROXYL IONS RELEASED BY CALCIUM HYDROXIDE PASTE

    PubMed Central

    FELIPPE, Mara Cristina Santos; FELIPPE, Wilson Tadeu; ESPEZIM, Catherine Schmitz; de FREITAS, Sérgio Fernando Torres

    2006-01-01

    Aim: To evaluate the effect of different irrigant solutions employed during removal and replacement of calcium hydroxide paste on the diffusion of hydroxyl ions through root canal dentine in vitro. Methodology: Thirty-five maxillary and mandibular human canines with straight and fully developed roots were used. After mechanical preparation up to 1mm short of tooth length, 30 canals were filled with calcium hydroxide paste and 5 canals were left empty; all teeth had their coronal accesses properly sealed. Teeth were placed in plastic containers with distilled water, and pH was read after 30 days when the paste from 20 teeth was renewed. After removal of the paste by endodontic instrumentation and irrigation with distilled water, canals were replenished with newly mixed paste in Group 1 and 2. In these groups, final irrigation was conducted with 5 mL of EDTA followed by 5 mL of NaOCl in specimens in Group 1, and 5 mL of NaOCl only in specimens in Group 2. In 10 teeth the paste was not replenished at 30 days (Group 3). All specimens were returned to the containers with fresh distilled water, and the pH was recorded after another 30 days. The differences between the first (30d) and second (60d) pH readings were calculated and submitted to analysis of variance and individual comparisons using the Scheffeé's test. Results: Results of mean analysis on differences of pH readings showed that greater diffusion had occurred on specimens in Group 3. Individual comparisons using Scheffeé's test showed statistical significance between Groups 2 and 3, and equivalence between all other groups. Conclusion: It was concluded that the use of EDTA did not enhance diffusion of hydroxyl ions through root canal dentine. PMID:19089021

  19. Effect of a calcium hydroxide/chlorhexidine paste as intracanal dressing in human primary teeth with necrotic pulp against Porphyromonas gingivalis and Enterococcus faecalis.

    PubMed

    Gondim, Juliana O; Avaca-Crusca, Juliana S; Valentini, Sandro R; Zanelli, Cleslei F; Spolidorio, Denise M P; Giro, Elisa M A

    2012-03-01

    Intracanal medication is important for endodontic treatment success as it eliminates microorganisms that persist after biomechanical preparation. Aim.  To evaluate the effect of two intracanal medications against Porphyromonas gingivalis and Enterococcus faecalis in the root canals of human primary teeth with necrotic pulp with and without furcal/periapical lesion, using quantitative real-time polymerase chain reaction (qRT-PCR). Thirty-two teeth with necrotic pulp were used. Twelve teeth did not present lesion, and 20 teeth presented radiographically visible furca/periapical lesion. Microbiological samples were collected after coronal access and biomechanical preparation. The teeth were medicated with calcium hydroxide pastes prepared with either polyethylene glycol or chlorhexidine. After 30days, the medication was removed and a third collection was performed. Microbiological samples were processed using qRT-PCR. Data were analysed by Wilcoxon and Mann-Whitney tests (α=0.05). There was no significant difference in the microbiota present in the primary teeth with and without furcal/periapical lesion. Biomechanical preparation was effective in reducing the number of microorganisms (P<0.05). The intracanal medications had similar antibacterial activity. The association of chlorhexidine with calcium hydroxide did not increase the antibacterial activity of the intracanal medication in the treatment of primary teeth with necrotic pulp with and without furcal/periapical lesion. © 2011 The Authors. International Journal of Paediatric Dentistry © 2011 BSPD, IAPD and Blackwell Publishing Ltd.

  20. Effect of double antibiotic and calcium hydroxide pastes on dislodgement resistance of an epoxy resin-based and two calcium silicate-based root canal sealers.

    PubMed

    Gokturk, Hakan; Bayram, Emre; Bayram, Huda Melike; Aslan, Tugrul; Ustun, Yakup

    2017-05-01

    The purpose of the present study was to determine the dislodgement resistance of AH Plus, MTA Fillapex, and Total Fill BC sealer to root canal dentin walls following placement of calcium hydroxide (CH) or double antibiotic paste (DAP) medicaments. Root canals of 90 single-rooted human mandibular premolar teeth were instrumented with Reciproc rotary instruments to a size R50. The teeth were randomly divided into two experimental groups: those receiving an intracanal medicament with either CH or DAP and a control group (n = 30). After 3 weeks, the medicaments were removed by irrigation with 5 mL of 2.5 % NaOCl, 5 mL 17 % EDTA, and 5 mL distilled water under sonic agitation. Each group was then subdivided into three subgroups (n = 10), and the canals were filled with either AH Plus, MTA Fillapex, or Total Fill BC sealer. After 1 week, a push-out test was applied to the specimens and the results were analyzed using one-way analysis of variance (ANOVA) and post hoc Tamhane's tests. Regardless of the type of intracanal medicament used, Total Fill BC Sealer and MTA Fillapex showed the highest and lowest bond strength, respectively (P < 0.05). The use or absence of medicaments did not significantly affect the dislodgment resistance of root canal fillings (P > 0.05). Prior CH placement improved dislodgement resistance of all sealers without statistical difference (P > 0.05). Adhesive failure between core and sealer was the most frequent failure mode. Prior application of CH or DAP did not significantly affect the adhesion of the AH Plus, MTA Fillapex, and Total Fill BC Sealers. There is a little information about the influence of antibiotic medicaments on the bond strength of root canal sealer. These findings suggest that the use of DAP does not affect the adhesion strength of AH Plus, MTA Fillapex, and Total Fill BC Sealers.

  1. Clinical and radiographic outcomes of calcium hydroxide and formocresol pulpotomies performed by dental students.

    PubMed

    Alaçam, Alev; Odabaş, Mesut E; Tüzüner, Tamer; Sillelioğlu, Hilal; Baygin, Ozgül

    2009-11-01

    The aim of this study was to compare the clinical and radiographic success rates of 3 pulpotomy techniques: formocresol, calcium hydroxide, and calcium hydroxide/iodoform. The pulpotomies were performed by fifth-year undergraduate dental students. Members of senior staff at the clinics supervised all of the procedures. Informed consent was obtained from each child's parents. The teeth were randomly assigned to the experimental (calcium hydroxide and calcium hydroxide/iodoform) or control (formocresol) groups. After coronal pulp removal and hemostasis, remaining pulp tissue was covered with calcium hydroxide or calcium hydroxide/iodoform paste in the experimental groups. In the control group, formocresol was placed with a cotton pellet over the pulp tissue for 5 minutes and removed; the pulp tissue was then covered with zinc oxide-eugenol. All teeth were restored with stainless-steel crowns. Clinical and radiographic successes and failures were recorded at 1-, 3-, 6-, and 12-month follow-ups by the authors. Data were statistically analyzed using chi-squared tests. The follow-up evaluations revealed that the clinical success rates were 89.7% for formocresol, 33.3% for calcium hydroxide, and 17.2% for calcium hydroxide/iodoform. The radiographic success rates were 89.7% for formocresol, 33.3% for calcium hydroxide, and 13.8% for calcium hydroxide/iodoform. Formocresol was superior to calcium hydroxide and calcium hydroxide/iodoform pastes for primary molar pulpotomies. Internal resorption was the most common radiographic failure in all 3 pulpotomy techniques.

  2. Microbial culture and checkerboard DNA-DNA hybridization assessment of bacteria in root canals of primary teeth pre- and post-endodontic therapy with a calcium hydroxide/chlorhexidine paste.

    PubMed

    Ito, Izabel Yoko; Junior, Fumio Matoba; Paula-Silva, Francisco Wanderley Garcia; Da Silva, Léa Assed Bezerra; Leonardo, Mário Roberto; Nelson-Filho, Paulo

    2011-09-01

    To investigate the root canal microbiota of primary teeth with apical periodontitis and the in vivo antimicrobial effects of a calcium hydroxide/chlorhexidine paste used as root canal dressing. Baseline samples were collected from 30 root canals of primary teeth with apical periodontitis. Then, the root canals were filled with a calcium hydroxide paste containing 1% chlorhexidine for 14 days and the second bacteriologic samples were taken prior to root canal filling. Samples were submitted to microbiologic culture procedure to detect root canal bacteria and processed for checkerboard DNA-DNA hybridization. Baseline microbial culture revealed high prevalence and cfu number of anaerobic, black-pigmented bacteroides, Streptococcus, and aerobic microorganisms. Following root canal dressing, the overall number of cfu was dramatically diminished compared to initial contamination (P <0.05), although prevalence did not change (P > 0.05). Of 35 probes used for checkerboard DNA-DNA hybridization, 31 (88.57%) were present at baseline, and following root canal dressing, the number of positive probes reduced to 13 (37.14%). Similarly, the number of bacterial cells diminished folowing application of calcium hydroxide/chlorhexidine root canal dressing (P = 0.006). Apical periodontitis is caused by a polymicrobial infection, and a calcium hydroxide/chlorhexidine paste is effective in reducing the number of bacteria inside root canals when applied as a root canal dressing. 2011 The Authors. International Journal of Paediatric Dentistry © 2011 BSPD, IAPD and Blackwell Publishing Ltd.

  3. Bacterial reduction in infected root canals treated with 2.5% NaOCl as an irrigant and calcium hydroxide/camphorated paramonochlorophenol paste as an intracanal dressing.

    PubMed

    Siqueira, José F; Magalhães, Karen M; Rôças, Isabela N

    2007-06-01

    This clinical study investigated the bacterial reduction after instrumentation using 2.5% sodium hypochlorite (NaOCl) as an irrigant and further interappointment dressing with a calcium hydroxide (Ca(OH)(2))/camphorated paramonochlorophenol (CPMC) paste. Eleven teeth with primary intraradicular infections and chronic apical periodontitis selected according to stringent inclusion/exclusion criteria followed in the study. Bacterial samples were taken before treatment (S1), after chemomechanical preparation using hand NiTi files and 2.5% NaOCl (S2), and following a 7-day medication with a Ca(OH)(2) paste in CPMC (S3). Cultivable bacteria recovered from infected root canals at the three stages were counted and identified by means of 16S rRNA gene sequencing analysis. At S1, all cases harbored bacteria, with a mean number of 2.8 taxa per canal (range, 1-6). At S2, 6 of 11 (54.5%) of the cases yielded positive cultures, with one to three species per canal. At S3, only one case (9.1%) was positive for the presence of bacteria, with Propionibacterium acnes as the only taxon isolated. A significantly high reduction in bacterial counts was observed between S1 and S2, and S1 and S3. Significant differences were also observed for comparisons involving S2 and S3 samples with regard to both quantitative bacterial reduction (p = 0.029) and number of culture-negative cases (p = 0.03). It was concluded that chemomechanical preparation with 2.5% NaOCl as an irrigant significantly reduced the number of bacteria in the canal but failed to render the canal free of cultivable bacteria in more than one-half of the cases. A 7-day intracanal dressing with Ca(OH)(2)/CPMC paste further significantly increased the number of culture-negative cases.

  4. Calcium hydroxide liners: a literature review

    PubMed Central

    Arandi, Naji Ziad

    2017-01-01

    Objective This review integrates the literature on cavity liners and current concepts of pulp protection with the aim of establishing a better understanding of the role of calcium hydroxide as a cavity liner. Materials and methods A search was conducted through PubMed, MEDLINE, and Ovid for articles with the criteria for the following terms: cavity liners and bases, pulp protection, and calcium hydroxide liners. No specific inclusion or exclusion criteria were applied as to what articles would be included in this review. It was hoped that the extent of the literature reviewed would be as comprehensive as possible. Conclusion This review underlines the fact that calcium hydroxide liners should only be used in the deepest spots in the cavity where the remaining dentine thickness is ≤0.5 mm. A protective layer of resin-modified glass ionomer should always follow the application of calcium hydroxide liners. PMID:28761378

  5. Efficacy of XP-endo finisher files in the removal of calcium hydroxide paste from artificial standardized grooves in the apical third of oval root canals.

    PubMed

    Wigler, R; Dvir, R; Weisman, A; Matalon, S; Kfir, A

    2017-07-01

    To compare the efficacy of the XP-endo finisher file (XP) (FKG Dentaire, La Chaux de Fonds, Switzerland) to that of passive ultrasonic irrigation (PUI) and conventional syringe and needle irrigation (SNI) in the removal of calcium hydroxide paste from an artificial standardized groove in the apical third of root canals. The root canals of 68 mandibular incisors with single oval canals were prepared using Mtwo instruments (VDW GmbH, Munich, Germany) up to size 40, .04 taper. Each tooth was split longitudinally, and in one half of the root, a standardized groove was prepared in the apical part of the specimen. The grooves were filled with Ca(OH)2 , and the root halves were reassembled. The roots were randomly divided into two control groups (n = 4) and three experimental groups (n = 20) according to the Ca(OH)2 methods used: XP, PUI and SNI. The amount of remaining medicament was evaluated under X25 magnification using a 4-grade scoring system. Kappa values were calculated for intra- and interobserver agreement evaluation. The differences in the Ca(OH)2 scores amongst the different groups were analysed using the Kruskal-Wallis test. None of the tested methods could completely clean the Ca(OH)2 from the artificial standardized groove in the apical third of the root canals. XP and PUI removed significantly more Ca(OH)2 than SNI (P < 0.001), with no significant differences between them (P = 0.238). XP and PUI were more effective in removing Ca(OH)2 from artificial standardized grooves in the apical third of root canals than SNI. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  6. Effect of calcium hydroxide and double and triple antibiotic pastes on the bond strength of epoxy resin-based sealer to root canal dentin.

    PubMed

    Akcay, Merve; Arslan, Hakan; Topcuoglu, Hüseyin Sinan; Tuncay, Oznur

    2014-10-01

    The aim of this study was to evaluate the effects of calcium hydroxide (CH) and triple (TAP) and double (DAP) antibiotic pastes on the bond strength of an epoxy resin-based sealer (AH Plus Jet; Dentsply DeTrey, Konstanz, Germany) to the root canal dentin. Sixty-four single-rooted human mandibular premolars were decoronated and prepared using the rotary system to size 40. The specimens were randomly divided into a control group (without intracanal dressing) and 3 experimental groups that received an intracanal dressing with either CH, DAP, or TAP (n = 16). The intracanal dressing was removed by rinsing with 10 mL 17% EDTA followed by 10 mL 2.5% sodium hypochlorite. The root canals were then obturated with gutta-percha and AH Plus Jet sealer. A push-out test was used to measure the bond strength between the root canal dentin and the sealer. The data were analyzed using 2-way analysis of variance and Tukey post hoc tests to detect the effect of the independent variables (intracanal medicaments and root canal thirds) and their interactions on the push-out bond strength of the root canal filling material to the root dentin (P = .05). The push-out bond strength values were significantly affected by the intracanal medicaments (P < .001) but not by the root canal thirds (P > .05). In the middle and apical third, the bond strength of the TAP group was higher than those of the CH and DAP groups (P < .05). The DAP and CH did not affect the bond strength of the epoxy resin-based sealer. Additionally, the TAP improved the bond strength of the epoxy resin-based sealer in the middle and apical thirds. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  7. INFLUENCE OF IODOFORM ON ANTIMICROBIAL POTENTIAL OF CALCIUM HYDROXIDE

    PubMed Central

    Estrela, Carlos; Estrela, Cyntia Rodrigues de Araújo; Hollanda, Augusto César Braz; Decurcio, Daniel de Almeida; Pécora, Jesus Djalma

    2006-01-01

    The purpose of this research was to verify the influence of Iodoform on antimicrobial potential of calcium hydroxide. S. aureus, E. faecalis, P. aeruginosa, B. subtilis, C. albicans were the biological indicators. The substances tested were: calcium hydroxide + saline; calcium hydroxide + Iodoform + saline; Iodoform + saline. For the agar diffusion test, 18 Petri plates with 20 ml of BHI agar were inoculated with the microbial suspensions. Fifty-four cavities were made and filled with the substances tested. The diameters of microbial inhibition were then measured. In direct exposure test, 162 #50 sterile absorbent paper points were immersed in the experimental suspensions for 5 min, and covered with the pastes. At intervals of 24, 48 and 72 hours, the paper points were immersed in 10 ml of Letheen Broth, followed by incubation at 37°°C for 48h. Microbial growth was evaluated by turbidity of the culture medium. A 0.1 ml inoculum obtained from the Letheen Broth was transferred to 7 ml of BHI, and incubated at 37°°C for 48h. Bacterial growth was again evaluated by turbidity of the culture medium. The calcium hydroxide associated with the saline or the iodoform plus saline showed antimicrobial effectiveness in both experimental methods. The iodoform paste presented antimicrobial ineffectiveness for the agar diffusion test on all biological microorganisms and for the direct exposure test on B. subtilis and on the mixture. PMID:19089027

  8. [Calcium hydroxide in the treatment of traumatized teeth].

    PubMed

    Cvek, M

    1989-09-01

    Calcium hydroxide is used in the treatment of different traumatized teeth. New concepts about the effects of calcium hydroxide on vital pulps and immature non vital teeth are developed. Some clinical techniques and their results are described.

  9. 21 CFR 184.1205 - Calcium hydroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Calcium hydroxide. 184.1205 Section 184.1205 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as...

  10. Analysis of barium hydroxide and calcium hydroxide slurry carbonation reactors

    SciTech Connect

    Patch, K.D.; Hart, R.P.; Schumacher, W.A.

    1980-05-01

    The removal of CO/sub 2/ from air was investigated by using a continuous-agitated-slurry carbonation reactor containing either barium hydroxide (Ba(OH)/sub 2/) or calcium hydroxide (Ca(OH)/sub 2/). Such a process would be applied to scrub /sup 14/CO/sub 2/ from stack gases at nuclear-fuel reprocessing plants. Decontamination factors were characterized for reactor conditions which could alter hydrodynamic behavior. An attempt was made to characterize reactor performance with models assuming both plug flow and various degrees of backmixing in the gas phase. The Ba(OH)/sub 2/ slurry enabled increased conversion, but apparently the process was controlled under some conditions by phenomena differing from those observed for carbonation by Ca(OH)/sub 2/. Overall reaction mechanisms are postulated.

  11. Particle size and shape of calcium hydroxide

    PubMed Central

    Komabayashi, Takashi; D’souza, Rena N; Dechow, Paul C; Safavi, Kamran E.; Spångberg, Larz S.W.

    2009-01-01

    The aim of this study was to examine the particle length, width, perimeter, and aspect ratio of calcium hydroxide powder using a flow particle image analyzer (FPIA). Five sample groups each with 10mg calcium hydroxide were mixed with 15mL of alcohol and sonicated. Digital images of the particle samples were taken using the FPIA and analyzed with a one-way ANOVA. The overall averages±S.D. among the five groups for particle length (μm), width (μm), perimeter (μm), and aspect ratio were 2.255±1.994, 1.620±1.464, 6.699±5.598, and 0.737±0.149, respectively. No statistical significance was observed among the groups for all parameters. When the total of 46,818 particles from all five groups were classified into the five length categories of 0.5μm increments, there were significant differences in width, perimeter, and aspect ratio (all p-values<0.0001). In conclusion, calcium hydroxide particles have a size and shape that may allow direct penetration into open dentin tubules. PMID:19166791

  12. Evaluation of antimicrobial efficacy of calcium hydroxide paste, chlorhexidine gel, and a combination of both as intracanal medicament: An in vivo comparative study

    PubMed Central

    Sinha, Nidhi; Patil, Santosh; Dodwad, Preeti Kore; Patil, Anand C; Singh, Bijay

    2013-01-01

    Aim: To compare the antimicrobial efficacy of calcium hydroxide (CH), 2% chlorhexidine gel (CHX) and a combination of both, on obligate anaerobes, facultative anaerobes and Candida spp . Materials and Methods: 90 single rooted permanent teeth were included in the study. After complete disinfection and access opening, the first microbiological pre-treatment sample (S1) was collected. After completion of instrumentation, a post-instumentation sample (S2) was taken and the teeth were divided into three groups: Group I: CH, Group II: 2% CHX, Group III: 2% CHX with CH. After 1 week, a post-medication sample (S3) was collected. Results: All three medicaments were effective in the elimination of obligate anaerobes. CHX and combination showed higher antimicrobial effect against facultative anaerobes and Candida spp. in comparison with CH. But there was no statistical significant difference between Group II and Group III. Conclusion: CHX with or without CH was more effective than CH alone against all the tested micro-organisms. PMID:23349580

  13. Evaluation of calcium ion, hydroxyl ion release and pH levels in various calcium hydroxide based intracanal medicaments: An in vitro study.

    PubMed

    Fulzele, Punit; Baliga, Sudhindra; Thosar, Nilima; Pradhan, Debaprya

    2011-10-01

    Evaluation of calcium ion and hydroxyl ion release and pH levels in various calcium hydroxide based intracanal medicaments. The purpose of this study was to evaluate calcium and hydroxyl ion release and pH levels of calcium hydroxide based products, namely, RC Cal, Metapex, calcium hydroxide with distilled water, along with the new gutta-percha points with calcium hydroxide. The materials were inserted in polyethylene tubes and immersed in deionized water. The pH variation, Ca(++) and OH(-) release were monitored periodically for 1 week. Statistical analysis was carried out using one-way analysis of variance and Tukey's post hoc tests with PASW Statistics version 18 software to compare the statistical difference. After 1 week, calcium hydroxide with distilled water and RC Cal raised the pH to 12.7 and 11.8, respectively, while a small change was observed for Metapex, calcium hydroxide gutta-percha points. The calcium released after 1 week was 15.36 mg/dL from RC Cal, followed by 13.04, 1.296, 3.064 mg/dL from calcium hydroxide with sterile water, Metapex and calcium hydroxide gutta-percha points, respectively. Calcium hydroxide with sterile water and RC Cal pastes liberate significantly more calcium and hydroxyl ions and raise the pH higher than Metapex and calcium hydroxidegutta-percha points.

  14. Evaluation of calcium ion, hydroxyl ion release and pH levels in various calcium hydroxide based intracanal medicaments: An in vitro study

    PubMed Central

    Fulzele, Punit; Baliga, Sudhindra; Thosar, Nilima; Pradhan, Debaprya

    2011-01-01

    Aims: Evaluation of calcium ion and hydroxyl ion release and pH levels in various calcium hydroxide based intracanal medicaments. Objective: The purpose of this study was to evaluate calcium and hydroxyl ion release and pH levels of calcium hydroxide based products, namely, RC Cal, Metapex, calcium hydroxide with distilled water, along with the new gutta-percha points with calcium hydroxide. Materials and Methods: The materials were inserted in polyethylene tubes and immersed in deionized water. The pH variation, Ca++ and OH- release were monitored periodically for 1 week. Statistical Analysis Used: Statistical analysis was carried out using one-way analysis of variance and Tukey's post hoc tests with PASW Statistics version 18 software to compare the statistical difference. Results: After 1 week, calcium hydroxide with distilled water and RC Cal raised the pH to 12.7 and 11.8, respectively, while a small change was observed for Metapex, calcium hydroxide gutta-percha points. The calcium released after 1 week was 15.36 mg/dL from RC Cal, followed by 13.04, 1.296, 3.064 mg/dL from calcium hydroxide with sterile water, Metapex and calcium hydroxide gutta-percha points, respectively. Conclusions: Calcium hydroxide with sterile water and RC Cal pastes liberate significantly more calcium and hydroxyl ions and raise the pH higher than Metapex and calcium hydroxidegutta-percha points. PMID:22346155

  15. Antimicrobial Activity of Calcium Hydroxide in Endodontics: A Review

    PubMed Central

    Shalavi, S; Yazdizadeh, M

    2012-01-01

    The purpose of endodontic therapy is to preserve the patient's natural teeth without compromising the patient's local or systemic health. Calcium hydroxide has been included in several materials and antimicrobial formulations that are used in several treatment modalities in endodontics, such as inter-appointment intracanal medicaments. The purpose of this article was to review the antimicrobial properties of calcium hydroxide in endodontics. Calcium hydroxide has a high pH (approximately 12.5-12.8) and is classified chemically as a strong base. The lethal effects of calcium hydroxide on bacterial cells are probably due to protein denaturation and damage to DNA and cytoplasmic membranes. Calcium hydroxide has a wide range of antimicrobial activity against common endodontic pathogens but is less effective against Enterococcus faecalis and Candida albicans. Calcium hydroxide is also a valuable anti-endotoxin agent. However, its effect on microbial biofilms is controversial. PMID:23323217

  16. Properties and applications of calcium hydroxide in endodontics and dental traumatology.

    PubMed

    Mohammadi, Z; Dummer, P M H

    2011-08-01

    Calcium hydroxide has been included within several materials and antimicrobial formulations that are used in a number of treatment modalities in endodontics. These include, inter-appointment intracanal medicaments, pulp-capping agents and root canal sealers. Calcium hydroxide formulations are also used during treatment of root perforations, root fractures and root resorption and have a role in dental traumatology, for example, following tooth avulsion and luxation injuries. The purpose of this paper is to review the properties and clinical applications of calcium hydroxide in endodontics and dental traumatology including its antibacterial activity, antifungal activity, effect on bacterial biofilms, the synergism between calcium hydroxide and other agents, its effects on the properties of dentine, the diffusion of hydroxyl ions through dentine and its toxicity. Pure calcium hydroxide paste has a high pH (approximately 12.5-12.8) and is classified chemically as a strong base. Its main actions are achieved through the ionic dissociation of Ca(2+) and OH(-) ions and their effect on vital tissues, the induction of hard-tissue deposition and the antibacterial properties. The lethal effects of calcium hydroxide on bacterial cells are probably due to protein denaturation and damage to DNA and cytoplasmic membranes. It has a wide range of antimicrobial activity against common endodontic pathogens but is less effective against Enterococcus faecalis and Candida albicans. Calcium hydroxide is also an effective anti-endotoxin agent. However, its effect on microbial biofilms is controversial. © 2011 International Endodontic Journal.

  17. 21 CFR 872.3250 - Calcium hydroxide cavity liner.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3250 Calcium hydroxide cavity liner. (a) Identification. A calcium hydroxide cavity liner is a device material intended to be applied to the interior of a prepared cavity before insertion of restorative material, such as amalgam, to protect the pulp of a tooth...

  18. Conversion coatings prepared or treated with calcium hydroxide solutions

    NASA Technical Reports Server (NTRS)

    Minevski, Zoran (Inventor); Clarke, Eric (Inventor); Maxey, Jason (Inventor); Nelson, Carl (Inventor); Eylem, Cahit (Inventor)

    2002-01-01

    A conversion coating process that forms a stable and corrosion-resistant oxide layer on metal or metal oxide substrates or layers. Particularly, the conversion coating process involves contacting the metal or metal oxide substrate or layer with the aqueous calcium hydroxide solutions in order to convert the surface of the substrate to a stable metal oxide layer or coating. According to the present invention, the calcium hydroxide solution is prepared by removing carbon dioxide from water or an aqueous solution before introducing the calcium hydroxide. In this manner, formation of calcium carbonate particles is avoided and the porosity of the conversion coating produced by the calcium hydroxide solution is reduced to below about 1%.

  19. [Development of a visible light-curing calcium hydroxide cement].

    PubMed

    Zhao, Xin-Yi; Kang, Biao; Liu, Han

    2005-05-01

    A visible light-curing calcium hydroxide cement is presented here and the effects of its resin matrix on the Ca2+ releasing, compressive strength of set material and the pH value of water in which set materials immersed are evaluated. Experimental results show that the effects of the selected resin matrix on Ca2+ releasing, compressive strength and pH value are significant. The calcium hydroxide cement containing BEMA or EMA and HEMA as resin matrix has good properties. The pulp capping test showed that an excellent dentin bridge appeared in dogs capped teeth at 70 days. pulp, pulp capping, calcium hydroxide, visible light-curing, dental materials

  20. Effect of root canal filling materials containing calcium hydroxide on the alkalinity of root dentin.

    PubMed

    Staehle, H J; Spiess, V; Heinecke, A; Müller, H P

    1995-08-01

    The effect of root canal filling pastes containing calcium oxide resp. calcium hydroxide on the alkalinity of extracted human teeth was investigated using a colour indicator (cresol red). An aqueous suspension of calcium hydroxide (Pulpdent), which is normally used for temporary root canal filling, most consistently produced alkalinity. Removal of the smear layer following instrumentation of the root canal led to increased proportion of alkaline-positive spots in dentinal locations distant from the canal. A clearly smaller effect was found with a calcium salicylate cement (Sealapex) and an oil-paste (Gangraena Merz), both of which are available for definite root canal fillings. Following removal of the smear layer, these hard-setting preparations caused moderate alkalinity in dentin adjacent to the canal but no effect was observed in locations more distant from the canal. Neither at locations adjacent to nor distant from the root canal was alkalinity found when another calcium salicylate cement (Apexit) was used. Apparently the release of hydroxyl ions into root dentin from calcium hydroxide containing root canal filling materials is not solely influenced by the absolute amount of calcium hydroxide, but also depends on other ingredients which variably inhibit the release of these ions.

  1. The reactivity of nano silica with calcium hydroxide.

    PubMed

    Lin, Qing; Xu, Zhongzi; Lan, Xianghui; Ni, Yaru; Lu, Chunhua

    2011-11-01

    The reactivity of nano silica (SiO₂) with calcium hydroxide (Ca(OH)₂) was evaluated and characterized in this study. Ca(OH)₂ activated nano SiO₂ takes place through an exothermic process, which is mainly attributed to the breakdown of Si-O-Si bonds. Ca(2+) offsets the charge imbalance and bonds to Si-OH and Si-O(-) giving rise to calcium silicate hydrate (CSH) gel. Care has to be taken that the reactivity of nano SiO₂ with Ca(OH) ₂significantly depends on the Q³ percentage in nano SiO ₂. Q³ percentages significantly influence the reaction kinetic of nano SiO₂ . The higher Q³ percentage results in a higher reaction degree of nano SiO₂ with Ca(OH)₂ and shorter setting times of the pastes. The higher Q³ percentage results in a lower total reaction heat of nano SiO₂ with Ca(OH)₂. It is suggested that the Q³ percentages of nano SiO₂ should be in excess of 30% to keep the satisfactory setting properties of the pastes for the application requirements of bone cement.

  2. Biocompatibility of Intracanal Medications Based on Calcium Hydroxide

    PubMed Central

    Andolfatto, Carolina; da Silva, Guilherme Ferreira; Cornélio, Ana Livia Gomes; Guerreiro-Tanomaru, Juliane Maria; Tanomaru-Filho, Mario; Faria, Gisele; Bonetti-Filho, Idomeo; Cerri, Paulo Sérgio

    2012-01-01

    Objective. The aim of this study was to evaluate the rat subcutaneous tissue reaction to calcium hydroxide-based intracanal medicaments, UltraCal XS (calcium hydroxide, barium sulphate, aqueous matrix), Hydropast (calcium hydroxide, barium sulphate, and propyleneglycol), and Calen (Calcium hydroxide, zinc oxide, colophony, and polyethyleneglycol), used as a control. Methods. Forty-eight rats (Rattus Norvegicus Holtzman) were distributed in three groups: Calen, UltraCal XS, and Hydropast. Polyethylene tubes filled with one of the medicaments were implanted in the dorsal subcutaneous. After 7 and 30 days, the implants were removed and the specimens were fixed and embedded in paraffin. Morphological and quantitative analyses were carried out in the HE-stained sections. The numerical density of inflammatory cells in the capsule was evaluated and statistical analyses were performed (P ≤ 0.05). Results. At 7 days, all materials induced an inflammatory reaction in the subcutaneous tissue adjacent to the implants. In all groups, a significant reduction in the number of inflammatory cells and giant cells was verified in the period of 30 days. Conclusion. These results indicate that the calcium hydroxide-based medicaments evaluated present biocompatibility similar to Calen. PMID:23320187

  3. Antibiofilm efficacy of silver nanoparticles as a vehicle for calcium hydroxide medicament against Enterococcus faecalis.

    PubMed

    Afkhami, Farzaneh; Pourhashemi, Seyyed Jalal; Sadegh, Mona; Salehi, Yasaman; Fard, Mohammad Javad Kharrazi

    2015-12-01

    The aim of the present study was to investigate antibacterial characteristic and Enterococcus faecalis (E. faecalis) biofilm suppression effect of different vehicles of calcium hydroxide as intracanal medicaments in short and long-term. Fifty-four human single-root teeth were contaminated with E. faecalis bacteria. The teeth were randomly divided into three experimental (n=16) and one control group (n=6). Each group was then exposed to various intracanal medicaments, namely calcium hydroxide paste (group 1), calcium hydroxide with chlorhexidine (group 2), calcium hydroxide with silver nanoparticles suspension (AgNPs) (group 3), and saline as the control group (group 4). Cultures were made from each group after one week and one month, and the number of colonies was counted. Moreover, a sample of each group was examined under electron microscope. Kruskal-Wallis test served for inter-group comparisons, and Mann-Whitney test served for comparison between the two incubation periods. All the intracanal medicaments resulted in significant decrease in number of colonies compared to control group in both incubation periods. After one week, the mixture of calcium hydroxide and AgNPs was the most effective medicament against E. faecalis bacteria (p<.05). No significant difference in antibacterial effect of the medicaments existed after one month incubation period (p>.05). AgNPs was more effective on the E. faecalis biofilm than other tested vehicles in short-term medication. AgNPs seems to have a good potential to be used as an appropriate vehicle of calcium hydroxide in order to eliminate of E. faecalis biofilm from human dentine in short-term. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. 21 CFR 872.3250 - Calcium hydroxide cavity liner.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Calcium hydroxide cavity liner. 872.3250 Section 872.3250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... prepared cavity before insertion of restorative material, such as amalgam, to protect the pulp of a...

  5. 21 CFR 872.3250 - Calcium hydroxide cavity liner.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Calcium hydroxide cavity liner. 872.3250 Section 872.3250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... prepared cavity before insertion of restorative material, such as amalgam, to protect the pulp of a...

  6. 21 CFR 872.3250 - Calcium hydroxide cavity liner.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Calcium hydroxide cavity liner. 872.3250 Section 872.3250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... prepared cavity before insertion of restorative material, such as amalgam, to protect the pulp of a...

  7. 21 CFR 872.3250 - Calcium hydroxide cavity liner.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Calcium hydroxide cavity liner. 872.3250 Section 872.3250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... prepared cavity before insertion of restorative material, such as amalgam, to protect the pulp of a...

  8. 21 CFR 184.1205 - Calcium hydroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... No. 1305-62-0) is also known as slaked lime or calcium hydrate. It is produced by the hydration of lime. (b) The ingredient meets the specifications of the Food Chemicals Codex, 3d Ed. (1981), p....

  9. Comparison of final irrigation techniques in removal of calcium hydroxide.

    PubMed

    Yücel, Ali Çağın; Gürel, Melek; Güler, Eda; Karabucak, Bekir

    2013-12-01

    The aim of this study was to compare new irrigation systems with a conventional irrigation technique for the removal of inter-appointment calcium hydroxide [Ca(OH)2 ]. Forty-seven extracted human single-rooted teeth were instrumented, and Ca(OH)2 paste was placed into root canals by using a lentulo spiral at the apical third. Teeth were randomly divided into three groups according to different irrigation protocols using a 30-gauge slot-tipped needle, EndoVac system and ProUltra® PiezoFlow™ ultrasonic irrigation system. Scanning electron microscopic images of the selected root canal surfaces (cervical, middle and apical third) were evaluated using a 5-grade scale. The influence of the irrigation system was evaluated using a two-way analysis of variance test and Tukey's test. The EndoVac and PiezoFlow groups demonstrated the lowest scale values (cleanest canals); however, there was no statistical difference between these two groups. The conventional irrigation group exhibited significantly higher scores (P < 0.05). The conventional needle irrigation was not sufficient to remove Ca(OH)2 from the root canal system. Irrigation with EndoVac and PiezoFlow™ ultrasonic irrigation systems improved the removal of the intracanal medicament resulting in cleaner root canal walls. © 2011 The Authors. Australian Endodontic Journal © 2011 Australian Society of Endodontology.

  10. [Conservative treatment of a case of periapical lesion with complications. Report of a case and calcium hydroxide therapy].

    PubMed

    Maráz, K; Gorzó, I; Olasz, T; Kapros, P

    1998-11-01

    A case and treatment of extraoral fistula on the chin-caused by necrotic pulp of lower left canine--is being presented. In this case an endodontic origin should always be considered from the aspect of differential diagnosis. Nonsurgical endodontic therapy, sometimes complimented by surgery, or extraction are the treatment modalities of these cases. For the treatment calcium hydroxide powder mixed with chlorhexidin gluckonat (0.1%) was used. Usage of calcium hydroxide paste was leaded to rapid and successful healing of extraoral lesions communicating with necrotic tooth.

  11. Characteristics of two calcium pectinates prepared from citrus pectin using either calcium chloride or calcium hydroxide.

    PubMed

    Guo, Xiujun; Duan, Hanying; Wang, Chao; Huang, Xuesong

    2014-07-09

    Calcium pectinate (CaP) was prepared from citrus pectin using either calcium chloride (C-CaP) or calcium hydroxide (HO-CaP) as the source of calcium for the reaction. The production yields and the rates of decalcification for the two calcium pectinates were compared and both found to be lower for C-CaP than for HO-CaP. In an attempt to explain these differences, certain chemical and structural characteristics of the two products, including functional groups (-CH3, C═O, COO-), rheological properties, morphology, and egg-box junction zones, were investigated by Fourier transformation infrared (FTIR) spectroscopy, rheology, scanning electron microscopy (SEM), and X-ray diffraction (XRD). The results from FTIR showed that, with an increase in calcium content, the wavenumber values and peak areas of FTIR for -CH3, C═O, and COO- groups all changed dramatically for C-CaP, while they were virtually unchanged for HO-CaP. Rheological analysis of the CaP gel showed that C-CaP had a stronger cross-linked network structure and a greater range of elastic behavior as compared to HO-CaP. SEM images of two CaP gels showed irregular membranes. C-CaP maintained a tight structure and a smooth surface, whereas HO-CaP was loose and rough. The results from XRD revealed a higher degree of crystallinity within C-CaP than within HO-CaP, which indicated that C-CaP possessed compact, ordered, and stable egg-box junction zones while the junction zones in HO-CaP were metastable and loose.

  12. Antimicrobial activity of calcium hydroxide and chlorhexidine on intratubular Candida albicans

    PubMed Central

    Jacques Rezende Delgado, Ronan; Helena Gasparoto, Thaís; Renata Sipert, Carla; Ramos Pinheiro, Claudia; Gomes de Moraes, Ivaldo; Brandão Garcia, Roberto; Antônio Hungaro Duarte, Marco; Monteiro Bramante, Clóvis; Aparecido Torres, Sérgio; Pompermaier Garlet, Gustavo; Paula Campanelli, Ana; Bernardineli, Norberti

    2013-01-01

    This study investigated the efficacy of calcium hydroxide and chlorhexidine gel for the elimination of intratubular Candida albicans (C. albicans). Human single-rooted teeth contaminated with C. albicans were treated with calcium hydroxide, 2% chlorhexidine gel, calcium hydroxide plus 2% chlorhexidine gel, or saline (0.9% sodium chloride) as a positive control. The samples obtained at depths of 0–100 and 100–200 µm from the root canal system were analyzed for C. albicans load by counting the number of colony forming units and for the percentage of viable C. albicans using fluorescence microscopy. First, the antimicrobial activity of calcium hydroxide and the 2% chlorhexidine gel was evaluated by counting the number of colony forming units. After 14 days of intracanal medication, there was a significant decrease in the number of C. albicans colony forming units at a depth of 0–100 µm with chlorhexidine treatment either with or without calcium hydroxide compared with the calcium hydroxide only treatment. However, there were no differences in the number of colony forming units at the 100–200 µm depth for any of the medications investigated. C. albicans viability was also evaluated by vital staining techniques and fluorescence microscopy analysis. Antifungal activity against C. albicans significantly increased at both depths in the chlorhexidine groups with and without calcium hydroxide compared with the groups treated with calcium hydroxide only. Treatments with only chlorhexidine or chlorhexidine in combination with calcium hydroxide were effective for elimination of C. albicans. PMID:23538639

  13. Influence of calcium hydroxide intracanal medication on the sealing ability of warm gutta-percha.

    PubMed

    Naaman, Alfred; Kaloustian, Hrant; Abboud, Nada Naaman-Bou; Ounsi, Hani Fouad; Ricci, Catherine; Medioni, Etienne

    2008-01-01

    This in vitro study sought to evaluate the influence of calcium hydroxide on the sealing ability of vertically condensed warm gutta-percha filling. Sixty single-rooted teeth were instrumented with a rotary system and divided randomly into two groups of 26 teeth each; the remaining eight teeth were divided into two groups of four to serve as negative and positive controls. The canals in the first group were filled with calcium hydroxide paste while the canals in the second group received no medication. Seven days after incubation, root canal dressings were removed by irrigation, using 5.25% sodium hypochlorite associated with ultrasonics and 50% citric acid. All specimens were filled using the warm gutta-percha vertical compaction technique, placed in test tubes containing India ink, and centrifuged at 30 G for five minutes; at that point, the dye penetration level was scored. Under the conditions of this study, the calcium hydroxide group showed significantly greater dye penetration than the non-medicated group.

  14. Effect of oil-based calcium hydroxide (Osteoinductal) on distraction osteogenesis in rabbit mandible.

    PubMed

    Polat, Hidayet Burak; Yeler, Hasan; Gumus, Cesur; Bulut, Huseyin Eray; Kucuk, Dervishan

    2009-06-01

    The objective of this study was to evaluate the effects of oil-based calcium hydroxide on mandibular lengthening during distraction osteogenesis. Twenty-four New Zealand white rabbits underwent unilateral mandibular osteotomy. The rabbits were divided into 4 groups containing 6 each: groups 1 and 3 were control groups and groups 2 and 4 were test groups. Oil-based calcium hydroxide suspension was applied to test groups' corticotomy gap after osteotomy during operation. No treatment was applied to the control groups. After 5 days' latency period, distraction was commenced at a rate of 0.8 mm/day for 10 days via custom-made distractor. Groups 1 and 2 were killed 14 days after distraction and groups 3 and 4 were killed 28 days after distraction. Quantitative computerized tomography evaluation did not demonstrate a difference mean the density and the area of the regeneration between groups 1 and 3, but there was a significant difference groups 2 and 4. Histomorphometric evaluation demonstrated that there was a significant difference between test and control groups in new bone volume formation during distraction osteogenesis. Application of oil-based calcium hydroxide paste during the osteotomy phase of distraction osteogenesis increased regeneration and new bone volume formation.

  15. Effects of calcium hydroxide and calcium chloride addition to bentonite in iron ore pelletization.

    PubMed

    Tugrul, Nurcan; Derun, Emek Moroydor; Pişkin, Mehmet

    2006-10-01

    Pyrite ash is created as waste from the roasting of pyrite ores during the production of sulphuric acid. These processes generate great amounts of pyrite ash waste that is generally land filled. This creates serious environmental pollution due to the release of acids and toxic substances. Pyrite ash waste can be utilized in the iron production industry as a blast furnace feed to process this waste and prevent environmental pollution. The essential parameters affecting the pelletization process of pyrite ash were studied using bentonite as a binder. Experiments were then carried out using bentonite and a mixture of bentonite with calcium hydroxide and calcium chloride in order to make the bentonite more effective. The metallurgical properties of pyrite ash, bentonite, calcium hydroxide, calcium chloride, a mixture of these and sintered pellets were studied using X-ray analysis. The crushing strength tests were carried out to investigate the strength of pyrite ash waste pellets. The results of these analyses showed that pyrite ash can be agglomerated to pellets and used in the iron production industry as a blast furnace feed. The crushing strength of the pellets containing calcium hydroxide and calcium chloride in addition to bentonite was better than the strength of pellets prepared using only bentonite binder.

  16. Antimicrobial Activity and pH of Calcium Hydroxide and Zinc Oxide Nanoparticles Intracanal Medication and Association with Chlorhexidine.

    PubMed

    Aguiar, Alana Souza; Guerreiro-Tanomaru, Juliane M; Faria, Gisele; Leonardo, Renato Toledo; Tanomaru-Filho, Mario

    2015-08-01

    To evaluate pH and antibacterial activity of pastes with calcium hydroxide [Ca(OH)2] and zinc oxide (ZnO) microparticles (micro) or nanoparticles (nano) and association with 0.4% chlorhexidine against Enterococcus faecalis. The following pastes were analyzed: Ca(OH)2/ZnO micro, (2) Ca(OH)2/ZnO nano, (3) Ca(OH)2/ ZnO micro + 0.4% chlorhexidine, (4) Ca(OH)2/ZnO nano + 0.4% chlorhexidine. Antibacterial activity against E. faecalis was evaluated by agar diffusion test. The direct contact test on planktonic cells of E. faecalis was performed for 30 and 60 seconds. Root canals from bovine teeth were filled with the pastes and pH was evaluated after 1, 7, 14, 21, 30 and 60 days. The data obtained were submitted to the statistical tests analysis of variance (ANOVA) and Tukey or Kruskal-Wallis and Dunn test, with a 5% significance level. Calcium hydroxide and zinc oxide nano, and the pastes with 0.4% chlorhexidine were more effective in agar diffusion test. In the direct contact test, the pastes with chlorhexidine showed the highest effect after 30 seconds. All pastes eliminated E. faecalis after 60 seconds. All pastes promoted an increase in pH. The highest increase in pH was observed with nanoparticle medications after 1 and 7 days (p < 0.05). After this period, the pastes presented similar pH increase. It was concluded that calcium hydroxide and zinc oxide nanoparticles promoted greater initial alkalinization. The antimicrobial activity of the pastes against E. faecalis is favored by the association with chlorhexidine. Although nanoparticles of calcium hydroxide and zinc oxide promoted antibacterial effect, the activity against E. faecalis is favored by association with chlorhexidine.

  17. Effects of aluminum hydroxide and calcium carbonate antacids on the bioavailability of ciprofloxacin.

    PubMed Central

    Frost, R W; Lasseter, K C; Noe, A J; Shamblen, E C; Lettieri, J T

    1992-01-01

    This study was designed to determine the effects of an aluminum hydroxide antacid and a calcium carbonate antacid on the bioavailability of ciprofloxacin (Cipro). Cipro (750 mg) was administered orally to 12 healthy volunteers in a three-way randomized crossover design. The three treatments included Cipro alone, four 850-mg calcium carbonate tablets taken 5 min before Cipro, and three 600-mg aluminum hydroxide tablets taken 5 min before Cipro. The relative bioavailability of Cipro when given with calcium carbonate was approximately 60% of the control value. When Cipro was given with aluminum hydroxide, the relative bioavailability was approximately 15%. Urinary recovery of Cipro in the aluminum hydroxide treatment group was approximately one-fourth of that in the calcium carbonate group. Although calcium carbonate decreased absorption to a lesser extent than aluminum hydroxide, these data suggest that antacids containing either aluminum or calcium should not be given concomitantly with Cipro. PMID:1503446

  18. Cytotoxicity Evaluation of Iranian Propolis and Calcium Hydroxide on Dental Pulp Fibroblasts

    PubMed Central

    Zare Jahromi, Maryam; Ranjbarian, Parisa; Shiravi, Samaneh

    2014-01-01

    Background and aims. Since intracanal medicaments can affect the cell viability in periapical tissues, the aim of this study was to evaluate the effect of calcium hydroxide and propolis on pulp fibroblasts. Materials and methods. Two healthy third molars were used as a source to obtain fibroblasts. The fibroblasts were cultured and subjected to 1 mg/mL of propolis and calcium hydroxide. This experiment was performed in six replicates and cell viability was evaluated with MTT assay. Statistical analysis was performed by t-test. Results. Comparison of cell viability with the use of 1 mg/mL of calcium hydroxide and propolis showed that cells subjected to propolis were more viable when compared to calcium hydroxide (P < 0.05). Conclusion. In this study, calcium hydroxide reduced fibroblast viability, significantly more than Iranian propolis. Other properties should be evaluated before Iranian propolis could be indicated for use as intracanal medicament. PMID:25346830

  19. Immature permanent teeth with apical periodontitis and abscess treated by regenerative endodontic treatment using calcium hydroxide and MTA: a report of two cases.

    PubMed

    Park, Mirae; Ahn, Byung Duk

    2014-01-01

    Regenerative endodontic techniques have been introduced to overcome the limits of the traditional apexification approach and allow continued root development after treatment of infected immature permanent teeth. The purpose of this report was to describe two cases with severe apical periodontitis and abscess that were successfully treated by regenerative endodontic treatment using calcium hydroxide. The report involves treatment of two patients who developed apical periodontitis and abscesses on their immature premolars affected by dens evaginatus. Regenerative endodontic treatment was performed using calcium hydroxide. The treatment procedures have been shown to result in increased thickening of root walls and encourage continued root development. Different outcomes were observed when calcium hydroxide was placed past and within the coronal half of the canal. Calcium hydroxide can be used as an effective medicament in regenerative endodontic technique, and successful regeneration can be expected even in severe cases of apical periodontitis or abscess.

  20. Carbonation as a binding mechanism for coal/calcium hydroxide pellets

    SciTech Connect

    Rapp, D.M.

    1991-01-01

    Current coal mining and processing procedures produce a significant quanity of fine coal that is difficult to handle and transport. The objective of this work is to determine if these fines can be economically pelletized with calcium hydroxide, a sulfur capturing sorbent, to produce a clean-burning fuel for fluidized-bed combustors or stoker boilers. To harden these pellets, carbonation, which is the reaction of calcium hydroxide with carbon dioxide to produce a cementitious matrix of calcium carbonate, is being investigated. Previous research indicated that carbonation significantly improved compressive strength, impact and attrition resistance and weatherproofed'' pellets formed with sufficient calcium hydroxide (5 to 10% for minus 28 mesh coal fines).

  1. Water sorption and solubility of different calcium hydroxide cements.

    PubMed

    Francisconi, Luciana Fávaro; de Freitas, Anderson Pinheiro; Scaffa, Polliana Mendes Candia; Mondelli, Rafael Francisco Lia; Francisconi, Paulo Afonso Silveira

    2009-01-01

    Calcium hydroxide cements have been largely used in deep cavities due to their abilities to stimulate dentin formation. However, their resistance can be relatively low and their solubility relatively high, in many instances. This study evaluated water sorption and solubility of different calcium hydroxide cements, in order to show alterations that may reduce their effectiveness. Five discs (20 mm in diameter and 1.5 mm thick) of three different materials (Biocal, Dycal and Hidro C) were prepared with the aid of a ring-shaped metallic matrix. After being stored at 37 degrees C for 24 h, the discs were weighed on a precision weight scale, dehydrated and weighed again. Immediately after weighing, discs were stored for a week in 50 mL of distilled water at 37 degrees C and, then, weighed again, dehydrated and submitted to a new weighing. The loss of soluble material and its water sorption was obtained from the difference between the initial and the final dry mass of each disc, after 1 week of immersion in water. Data were analyzed for significant differences by two-way ANOVA and Tukey's test (p<0.05). Mean water sorption values (g) +/- standard deviation and percentage (%), for each evaluated cement, were: Biocal (0.006 +/- 0.001 / 2.15); Dycal (0.016 +/- 0.004 / 5.49); and Hidro C (0.025 +/- 0.003 / 8.27). Mean solubility values (g) +/- standard deviation and percentage (%), for each evaluated cement, were: Biocal (0.002 +/- 0.001 / 0.72); Dycal (0.013 +/- 0.004 / 4.21); and Hidro C (0.023 +/- 0.004 / 7.65). Biocal absorbed less water and was less soluble than the other evaluated cements; Hidro C exhibited the highest water sorption and solubility values; and there were significant differences among all evaluated experimental groups.

  2. ASSOCIATION OF CALCIUM HYDROXIDE AND METRONIDAZOLE IN THE TREATMENT OF DOG'S TEETH WITH CHRONIC PERIAPICAL LESION

    PubMed Central

    Panzarini, Sônia Regina; Souza, Valdir; Holland, Roberto; Dezan, Eloi

    2006-01-01

    One of the primary objectives of endodontic treatment of teeth with pulp necrosis is the elimination of microorganisms from the root canal system, as effectively as possible, especially in cases with chronic periapical lesions. AIM: The purpose of this study was to analyze the response of the periapical tissue of dogs' teeth with chronic periapical lesions to endodontic treatment performed with utilization of metronidazole, calcium hydroxide, and an association of both as root canal dressings. METHODOLOGY: Forty root canals were submitted to pulpectomy and the root canals were kept exposed to the oral environment for 6 months. Then, they were submitted to biomechanical preparation and divided into 4 study groups with 10 specimens: group I – no root canal dressing; group II – calcium hydroxide; group III – metronidazole; group IV – calcium hydroxide associated to metronidazole. After 15 days, the root canals were filled with Fill Canal sealer. After 90 days, the animals were killed and the especimens processed for histological analysis. RESULTS: Calcium hydroxide dressing provided a significantly better outcome compared to other experimental groups (α = 0.01). Also, the results of the association of metronidazole and calcium hydroxide were similar to those observed for the metronidazole group. The worst results were obtained by the no root canal dressing group. CONCLUSION: The use of metronidazole alone or associated with Calcium hydroxide, did not improve periapical healing when compared to Calcium hydroxide dressing. PMID:19089054

  3. X-ray diffraction investigations of deformations and dislocation configuration in calcium hydroxide crystallites of concrete

    NASA Astrophysics Data System (ADS)

    Harutyunyan, V. S.; Abovyan, E. S.; Monteiro, P. J. M.

    2003-12-01

    On the bases of proposed theoretical approach for analysis of X-ray diffraction spectra the peculiarities of morphology, deformations, stresses and dislocation configuration of calcium hydroxide crystallites of interfacial transition zone in high-strength concrete (the water-cement ratio is about 0.35) are investigated. It is determined that the (0001) dislocation slip planes dividing the calcium hydroxide crystallites into coherent domains are arranged in them quasi-periodically along c-crystallographic axis. For dislocation configuration in crystallites the so-called multilayer dislocation multipole configuration is proposed. From the reconstructed strain distribution function of coherent domains it was concluded that the most part of them are subjected to compressive strain caused most probably due to drying shrinkage phenomenon. The intrinsic stresses of crystallites are estimated for uniaxial compressive, hydrostatic compressive, and shear types of deformation. A possibility for dislocation pile-ups formation in (0001) atomic planes (domain boundaries) is considered theoretically as well. From comparative analyses of intrinsic stresses of crystallites with their ultimate stresses it is assumed that the main mechanism leading to failure of calcium hydroxide both in interfacial transition zone and cement paste of concrete are dislocation pile-ups which form against phase inclusions because of action of external shear stresses. The results are obtained and compared for two samples with granite and smoky quartz aggregates. It is assumed that the proposed theoretical approach for analysis of X-ray diffraction spectra could be perspective especially for investigations of nanostructured polycrystalline materials with a columnar structure. (

  4. Pulp revascularization after root canal decontamination with calcium hydroxide and 2% chlorhexidine gel.

    PubMed

    Soares, Adriana de Jesus; Lins, Fernanda Freitas; Nagata, Juliana Yuri; Gomes, Brenda Paula Figueiredo de Almeida; Zaia, Alexandre Augusto; Ferraz, Caio Cezar Randi; de Almeida, José Flávio Affonso; de Souza-Filho, Francisco José

    2013-03-01

    Pulp revascularization may be considered a promising alternative for necrotic immature teeth. Many studies have accomplished passive decontamination associated with an antibiotic paste. To date, there is no report evaluating calcium hydroxide associated with 2% chlorhexidine gel for revascularization therapy. The aim of this case report was to describe a new proposal for pulp revascularization with mechanical decontamination and intracanal medication composed of calcium hydroxide and 2% chlorhexidine gel. The patient, a 9-year-old girl, suffered an intrusion associated with pulp exposure caused by an enamel-dentin fracture in her maxillary left central incisor. After diagnosis, treatment consisted of revascularization therapy with gentle manual instrumentation of the cervical and medium thirds of the root in addition to intracanal medication with calcium hydroxide and 2% chlorhexidine gel for 21 days. In the second session, a blood clot was stimulated up to the cervical third of the root canal. Mineral trioxide aggregate (MTA; Angelus, Londrina, Paraná, Brazil) was used for cervical sealing of the canal. Coronal sealing was performed with temporary filling material and composite resin. During the follow-up period, the root canal space showed a progressive decrease in width, mineralized tissue deposition on root canal walls, and apical closure. A cone-beam computed tomography scan taken at the 2-year follow-up confirmed these findings and did not show complete root canal calcification. This new proposal for revascularization therapy with 2% chlorhexidine gel may be used for the treatment of necrotic immature root canals. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. WATER SORPTION AND SOLUBILITY OF DIFFERENT CALCIUM HYDROXIDE CEMENTS

    PubMed Central

    Francisconi, Luciana Fávaro; de Freitas, Anderson Pinheiro; Scaffa, Polliana Mendes Candia; Mondelli, Rafael Francisco Lia; Francisconi, Paulo Afonso Silveira

    2009-01-01

    Objectives: Calcium hydroxide cements have been largely used in deep cavities due to their abilities to stimulate dentin formation. However, their resistance can be relatively low and their solubility relatively high, in many instances. This study evaluated water sorption and solubility of different calcium hydroxide cements, in order to show alterations that may reduce their effectiveness. Material and methods: Five discs (20 mm in diameter and 1.5 mm thick) of three different materials (Biocal®, Dycal® and Hidro C®) were prepared with the aid of a ring-shaped metallic matrix. After being stored at 37°C for 24 h, the discs were weighed on a precision weight scale, dehydrated and weighed again. Immediately after weighing, discs were stored for a week in 50 mL of distilled water at 37°C and, then, weighed again, dehydrated and submitted to a new weighing. The loss of soluble material and its water sorption was obtained from the difference between the initial and the final dry mass of each disc, after 1 week of immersion in water. Data were analyzed for significant differences by two-way ANOVA and Tukey's test (p<0.05). Results: Mean water sorption values (g) ± standard deviation and percentage (%), for each evaluated cement, were: Biocal® (0.006 ± 0.001 / 2.15); Dycal® (0.016 ± 0.004 / 5.49); and Hidro C® (0.025 ± 0.003 / 8.27). Mean solubility values (g) ± standard deviation and percentage (%), for each evaluated cement, were: Biocal® (0.002 ± 0.001 / 0.72); Dycal® (0.013 ± 0.004 / 4.21); and Hidro C® (0.023 ± 0.004 / 7.65). Conclusions: Biocal® absorbed less water and was less soluble than the other evaluated cements; Hidro C® exhibited the highest water sorption and solubility values; and there were significant differences among all evaluated experimental groups. PMID:19936520

  6. Influence of calcium hydroxide debris on the quality of endodontic apical seal.

    PubMed

    Contardo, L; De Luca, M; Bevilacqua, L; Breschi, L; Di Lenarda, R

    2007-10-01

    The aim of the study was to study investigate the influence of calcium hydroxide used as intermediate medication on the quality of apical seal of a silicon based and an experimental resin based endodontic sealer. Eighty endodontic canals were prepared and divided in four groups. Calcium hydroxide was applied in groups 2 and 4. After 7 days, medication was removed and canals were filled with gutta-percha and RoekoSeal Automix (groups 1 and 2) or Scotchbond MP+C&B cement B (groups 3 and 4). Specimens were placed into India ink, cleared and analyzed under a stereomicroscope to investigate apical leakage. Specimens that received calcium hydroxide medication showed leakage means higher than the corresponding untreated ones (i.e. group 1< group 2 and group 3< group 4; P<0.001). Calcium hydroxide interferes with the sealing ability of silicon based sealer, since it frequently remains entrapped within the endodontic space even after careful removal procedures.

  7. Ion release and mechanical properties of calcium silicate and calcium hydroxide materials used for pulp capping.

    PubMed

    Natale, L C; Rodrigues, M C; Xavier, T A; Simões, A; de Souza, D N; Braga, R R

    2015-01-01

    To compare the ion release and mechanical properties of a calcium hydroxide (Dycal) and two calcium silicate (MTA Angelus and Biodentine) cements. Calcium and hydroxyl ion release in water from 24-h set cements were calculated from titration with HCl (n = 3). Calcium release after 7, 14, 21 and 28 days at pH 5.5 and 7.0 was measured using ICP-OES (n = 6). Flexural strength (FS) and modulus (E) were tested after 48-h storage, and compressive strength (CS) was tested after 48 h and 7 days (n = 10). Ion release and mechanical data were subjected to anova/Tukey and Kruskal-Wallis/Mann-Whitney tests, respectively (α = 0.05). Titration curves revealed that Dycal released significantly fewer ions in solution than calcium silicates (P < 0.001). Calcium release remained constant at pH 7.0, whilst at pH 5.5, it dropped significantly by 24% after 21 days (P < 0.05). At pH 5.5, MTA Angelus released significantly more calcium than Dycal (P < 0.01), whilst Biodentine had superior ion release than Dycal at pH 7.0 (P < 0.01). Biodentine had superior flexural strength, flexural modulus and compressive strength than the other cements, whilst MTA Angelus had higher modulus than Dycal (P < 0.001). Immediate calcium and hydroxyl ion release in solution was significantly lower for Dycal. In general, all materials released constant calcium levels over 28 days, but release from Dycal was significantly lower than Biodentine and MTA Angelus depending on pH conditions. Biodentine had substantially higher strength and modulus than MTA Angelus and Dycal, both of which demonstrated low stress-bearing capabilities. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  8. Toxicity of Calcium Hydroxide Nanoparticles on Murine Fibroblast Cell Line

    PubMed Central

    Dianat, Omid; Azadnia, Sina; Mozayeni, Mohammad Ali

    2015-01-01

    Introduction: One of the major contributing factors, which may cause failure of endodontic treatment, is the presence of residual microorganisms in the root canal system. For years, most dentists have been using calcium hydroxide (CH) as the intracanal medicament between treatment sessions to eliminate remnant microorganisms. Reducing the size of CH particles into nanoparticles enhances the penetration of this medicament into dentinal tubules and increases their antimicrobial efficacy. This in vitro study aimed to compare the cytotoxicity of CH nanoparticles and conventional CH on fibroblast cell line using the Mosmann’s Tetrazolium Toxicity (MTT) assay. Methods and Materials: This study was conducted on L929 murine fibroblast cell line by cell culture and evaluation of the direct effect of materials on the cultured cells. Materials were evaluated in two groups of 10 samples each at 24, 48 and 72 h. At each time point, 10 samples along with 5 positive and 5 negative controls were evaluated. The samples were transferred into tubes and exposed to fibroblast cells. The viability of cells was then evaluated. The Two-way ANOVA was used for statistical analysis and the level of significance was set at 0.05. Results: Cytotoxicity of both materials decreased over time and for conventional CH was lower than that of nanoparticles. However, this difference was not statistically significant (P>0.05). Conclusion: The cytotoxicity of CH nanoparticles was similar to that of conventional CH. PMID:25598810

  9. Surface properties of kaolin and illite suspensions in concentrated calcium hydroxide medium.

    PubMed

    Konan, Koffi Léon; Peyratout, Claire; Bonnet, Jean-Pierre; Smith, Agnès; Jacquet, Alain; Magnoux, Patrick; Ayrault, Philippe

    2007-03-01

    The adsorption behaviour of calcium hydroxide onto illite and kaolin clay minerals was investigated by monitoring with atomic emission spectroscopy and pH measurements the amounts of ions left in solution after exposing clay minerals to calcium hydroxide solutions of various concentrations. Both clay minerals can adsorb calcium and hydroxyl ions. Rather than just considering proton exchanges at the clay mineral surfaces, the adsorption is explained by an approach based on Lewis description of molecules. With this approach, a mechanism for calcium hydroxide adsorption not only at the edges of the clay particles but also onto the faces is proposed. In order to gain a better insight onto the active groups at the surface of the studied clay minerals, adsorption of pyridine and ammonia on illite and kaolin was followed by FTIR spectroscopy. These measurements gave the signature of edges, which are marginally involved in interactions with calcium ions.

  10. Microstructure of amorphous aluminum hydroxide in belite-calcium sulfoaluminate cement

    SciTech Connect

    Song, Fei; Yu, Zhenglei; Yang, Fengling; Lu, Yinong Liu, Yunfei

    2015-05-15

    Belite-calcium sulfoaluminate (BCSA) cement is a promising low-CO{sub 2} alternative to ordinary Portland cement. Herein, aluminum hydroxide (AH{sub 3}), the main amorphous hydration product of BCSA cement, was investigated in detail. The microstructure of AH{sub 3} with various quantities of gypsum was investigated via scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The AH{sub 3} with various morphologies were observed and confirmed in the resulting pastes. Particular attention was paid to the fact that AH{sub 3} always contained a small amount of Ca according to the results of EDS analysis. The AH{sub 3} was then characterized via high resolution transmission electron microscopy (HRTEM). The results of HRTEM indicated that Ca arose from nanosized tricalcium aluminate hexahydrate which existed in the AH{sub 3}.

  11. A titration model for evaluating calcium hydroxide removal techniques.

    PubMed

    Phillips, Mark; McClanahan, Scott; Bowles, Walter

    2015-01-01

    Calcium hydroxide (Ca(OH)2) has been used in endodontics as an intracanal medicament due to its antimicrobial effects and its ability to inactivate bacterial endotoxin. The inability to totally remove this intracanal medicament from the root canal system, however, may interfere with the setting of eugenol-based sealers or inhibit bonding of resin to dentin, thus presenting clinical challenges with endodontic treatment. This study used a chemical titration method to measure residual Ca(OH)2 left after different endodontic irrigation methods. Eighty-six human canine roots were prepared for obturation. Thirty teeth were filled with known but different amounts of Ca(OH)2 for 7 days, which were dissolved out and titrated to quantitate the residual Ca(OH)2 recovered from each root to produce a standard curve. Forty-eight of the remaining teeth were filled with equal amounts of Ca(OH)2 followed by gross Ca(OH)2 removal using hand files and randomized treatment of either: 1) Syringe irrigation; 2) Syringe irrigation with use of an apical file; 3) Syringe irrigation with added 30 s of passive ultrasonic irrigation (PUI), or 4) Syringe irrigation with apical file and PUI (n=12/group). Residual Ca(OH)2 was dissolved with glycerin and titrated to measure residual Ca(OH)2 left in the root. No method completely removed all residual Ca(OH)2. The addition of 30 s PUI with or without apical file use removed Ca(OH)2 significantly better than irrigation alone. This technique allowed quantification of residual Ca(OH)2. The use of PUI (with or without apical file) resulted in significantly lower Ca(OH)2 residue compared to irrigation alone.

  12. Cysteamine Enhances Biofilm Eradication Efficacy of Calcium Hydroxide.

    PubMed

    Guo, Weidi; Quah, Samantha Yiling; Lim, Kian Chong; Yu, Victoria Soo Hoon; Tan, Kai Soo

    2016-05-01

    Calcium hydroxide (Ca[OH]2) is a widely used interappointment dressing, but its antibacterial property is compromised by dentin. Hence, the addition of chlorhexidine (CHX) with Ca(OH)2 has been proposed. However, the antimicrobial efficacy of this mixture compared with Ca(OH)2 alone is currently still debatable. Cysteamine is a mucolytic agent used to reduce the viscosity of mucus through the disruption of proteins, which are also important components of the extracellular matrix of biofilms. The aims of this study were to determine the efficacy of cysteamine alone and in combination with Ca(OH)2 to eradicate Enterococcus faecalis biofilm compared with CHX with Ca(OH)2, and to determine if this effect is affected by dentin. The biofilm eradication efficacies of Ca(OH)2 alone and with cysteamine were determined using 7-day E. faecalis biofilm cultured on dentin discs and compared with Ca(OH)2 with 2% CHX. The effects of dentin on the efficacies of Ca(OH)2 alone and with either cysteamine or CHX were examined. Cysteamine alone completely abolished E. faecalis biofilm at 200 mg/mL. The combination of Ca(OH)2 with either cysteamine at 10 mg/mL or 2% CHX completely obliterated E. faecalis biofilm. Cysteamine with Ca(OH)2 completely eradicated E. faecalis biofilm despite preincubation with dentin, whereas CHX with Ca(OH)2 was less effective. Cysteamine effectively eliminated E. faecalis biofilm and showed synergistic effects in combination with Ca(OH)2, which were unaffected by dentin. Hence, our findings support the use of cysteamine as a potential adjunct to Ca(OH)2 as an interappointment dressing. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  13. A titration model for evaluating calcium hydroxide removal techniques

    PubMed Central

    PHILLIPS, Mark; McCLANAHAN, Scott; BOWLES, Walter

    2015-01-01

    Objective Calcium hydroxide (Ca(OH)2) has been used in endodontics as an intracanal medicament due to its antimicrobial effects and its ability to inactivate bacterial endotoxin. The inability to totally remove this intracanal medicament from the root canal system, however, may interfere with the setting of eugenol-based sealers or inhibit bonding of resin to dentin, thus presenting clinical challenges with endodontic treatment. This study used a chemical titration method to measure residual Ca(OH)2 left after different endodontic irrigation methods. Material and Methods Eighty-six human canine roots were prepared for obturation. Thirty teeth were filled with known but different amounts of Ca(OH)2 for 7 days, which were dissolved out and titrated to quantitate the residual Ca(OH)2 recovered from each root to produce a standard curve. Forty-eight of the remaining teeth were filled with equal amounts of Ca(OH)2 followed by gross Ca(OH)2 removal using hand files and randomized treatment of either: 1) Syringe irrigation; 2) Syringe irrigation with use of an apical file; 3) Syringe irrigation with added 30 s of passive ultrasonic irrigation (PUI), or 4) Syringe irrigation with apical file and PUI (n=12/group). Residual Ca(OH)2 was dissolved with glycerin and titrated to measure residual Ca(OH)2 left in the root. Results No method completely removed all residual Ca(OH)2. The addition of 30 s PUI with or without apical file use removed Ca(OH)2 significantly better than irrigation alone. Conclusions This technique allowed quantification of residual Ca(OH)2. The use of PUI (with or without apical file) resulted in significantly lower Ca(OH)2 residue compared to irrigation alone. PMID:25760272

  14. Comparison of sodium hydroxide and calcium hydroxide pretreatments on the enzymatic hydrolysis and lignin recovery of sugarcane bagasse.

    PubMed

    Chang, Menglei; Li, Denian; Wang, Wen; Chen, Dongchu; Zhang, Yuyuan; Hu, Huawen; Ye, Xiufang

    2017-08-19

    Sodium hydroxide (NaOH) and calcium hydroxide (Ca(OH)2) respectively dissolved in water and 70% glycerol were applied to treat sugarcane bagasse (SCB) under the condition of 80°C for 2h. NaOH solutions could remove more lignin and obtain higher enzymatic hydrolysis efficiency of SCB than Ca(OH)2 solutions. Compared with the alkali-water solutions, the enzymatic hydrolysis of SCB treated in NaOH-glycerol solution decreased, while that in Ca(OH)2-glycerol solution increased. The lignin in NaOH-water pretreatment liquor could be easily recovered by calcium chloride (CaCl2) at room temperature, but that in Ca(OH)2-water pretreatment liquor couldn't. NaOH pretreatment is more suitable for facilitating enzymatic hydrolysis and lignin recovery of SCB than Ca(OH)2 pretreatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Apexification of an Immature Permanent Incisor with the Use of Calcium Hydroxide: 16-Year Follow-Up of a Case

    PubMed Central

    Silveira, Camila Maggi Maia; Sebrão, Cátia Cilene Nass; Vilanova, Larissa Soares Reis; Sánchez-Ayala, Alfonso

    2015-01-01

    Apexification is a process of forming a mineralized apical barrier and had been performed by using calcium hydroxide paste, due to its biological and healing performances in cases of existent trauma. This clinical report aims to report the results of a 16-year follow-up study of an apexification treatment applied to nonvital tooth 22 of a healthy 8-year-old male after a trauma. Clinical inspection of the tooth showed fractures of the incisal edge and mesial angle, absence of coronal mobility, and negative pulp vitality under cold testing. Radiographic analysis of the root revealed incomplete apex formation. The possibility of fracture into the root or luxation injury was rejected, and the diagnosis of pulp necrosis was verified. Apexification by calcium hydroxide and subsequent endodontic treatment were planned. Initial formation of the mineralized apical barrier was observed after 3 months, and the barrier was considered to be completed after 8 months. Clinical, radiographic, and CBCT examinations after 16 years verified the success of the treatment, although the choice of calcium hydroxide for apexification treatment is discussed. PMID:26171256

  16. A role for calcium hydroxide and dolomite in water: acceleration of the reaction under ultraviolet light.

    PubMed

    Nagase, Hiroyasu; Tsujino, Hidekazu; Kurihara, Daisuke; Saito, Hiroshi; Kawase, Masaya

    2014-04-01

    Organic environmental pollutants are now being detected with remarkably high frequency in the aquatic environment. Photodegradation by ultraviolet light is sometimes used as a method for removing organic chemicals from water; however, this method is relatively inefficient because of the low degradation rates involved, and more efficient methods are under development. Here we show that the removal of various organic pollutants can be assisted by calcined dolomite in aqueous solution under irradiation with ultraviolet light. It was possible to achieve substantial removal of bisphenol A, chlorophenols, alkylphenols, 1-naphthol and 17β-estradiol. The major component of dolomite responsible for the removal was calcium hydroxide. Our results demonstrate that the use of calcium hydroxide with ultraviolet light irradiation can be a very effective method of rapidly removing organic environmental pollutants from water. This is a new role for calcium hydroxide and dolomite in water treatment.

  17. Determination of Ksp, , , and for the Dissolution of Calcium Hydroxide in Water: A General Chemistry Experiment

    NASA Astrophysics Data System (ADS)

    Euler, William B.; Kirschenbaum, Louis J.; Ruekberg, Ben

    2000-08-01

    The molar solubility of sparingly soluble calcium hydroxide in water at room temperature and in boiling water is easily determined by titration of filtered saturated solutions with standardized hydrochloric acid solution. The apparent equilibrium constant, Ksp, can be calculated from the molar solubility of calcium hydroxide: Ksp = [Ca2+][OH-]2. The ? for the dissolution of calcium hydroxide at each temperature is calculated from the formula ? = -RT ln(Kc). ? values at two temperatures permit the calculation of ? and ?. This exercise utilizes low-cost, relatively nonhazardous materials presenting few disposal problems. It reinforces the students' understanding of the interrelationship of solubility, Ksp, ? , ? and ?. The significant extent of Ca(OH)2 solubility and its favorable temperature variation provide unique conditions for the success of this experiment.

  18. Lack of genotoxicity of formocresol, paramonochlorophenol, and calcium hydroxide on mammalian cells by comet assay.

    PubMed

    Ribeiro, Daniel Araki; Marques, Mariângela Esther Alencar; Salvadori, Daisy Maria Fávero

    2004-08-01

    Formocresol, paramonochlorophenol, and calcium hydroxide are widely used in dentistry because of their antibacterial activities in root canal disinfection. However, the results of genotoxicity studies using these materials are inconsistent in literature. The goal of this study was to examine the genotoxic potential of formocresol, paramonochlorophenol, and calcium hydroxide using mouse lymphoma cells and human fibroblasts cells in vitro by the comet assay. Data were assessed by Kruskal-Wallis nonparametric test. The results showed that all compounds tested did not cause DNA damage for the tail moment or tail intensity parameters. These findings suggest that formocresol, paramonochlorophenol, and calcium hydroxide do not promote DNA damage in mammalian cells and that the comet assay is a suitable tool to investigate genotoxicity.

  19. Ablation of prion protein immunoreactivity by heating in saturated calcium hydroxide

    PubMed Central

    Greenlee, Justin J; Nicholson, Eric M; Hamir, Amir N; Noyes, Gary P; Holtzapple, Mark T; Kehrli, Marcus E

    2008-01-01

    Background Prions, the infectious agents that cause transmissible spongiform encephalopathies (TSEs), are relatively resistant to destruction by physical, enzymatic, and chemical treatments. Hydrolysis in boiling saturated calcium hydroxide (limewater) utilizes inexpensive chemicals to digest protein components of offal. The purpose of this work was to determine if incubating brain material from scrapie-infected sheep in near-boiling saturated calcium hydroxide solution (Ca(OH)2) would abolish immunoreactivity of the infectious prion (PrPSc) as determined by western blot. Findings After incubating for as few as 10 minutes in saturated calcium hydroxide at 99°C, immunoreactivity of protease resistant bands by western blot analysis is completely lost. Conclusion Boiling in limewater may offer an alternative for disposal of carcasses and enable alternative uses for rendered products from potentially infected carcasses. PMID:18957103

  20. Ablation of prion protein immunoreactivity by heating in saturated calcium hydroxide.

    PubMed

    Greenlee, Justin J; Nicholson, Eric M; Hamir, Amir N; Noyes, Gary P; Holtzapple, Mark T; Kehrli, Marcus E

    2008-10-28

    Prions, the infectious agents that cause transmissible spongiform encephalopathies (TSEs), are relatively resistant to destruction by physical, enzymatic, and chemical treatments. Hydrolysis in boiling saturated calcium hydroxide (limewater) utilizes inexpensive chemicals to digest protein components of offal. The purpose of this work was to determine if incubating brain material from scrapie-infected sheep in near-boiling saturated calcium hydroxide solution (Ca(OH)2) would abolish immunoreactivity of the infectious prion (PrPSc) as determined by western blot. After incubating for as few as 10 minutes in saturated calcium hydroxide at 99 degrees C, immunoreactivity of protease resistant bands by western blot analysis is completely lost. Boiling in limewater may offer an alternative for disposal of carcasses and enable alternative uses for rendered products from potentially infected carcasses.

  1. Dental stem cell therapy with calcium hydroxide in dental pulp capping.

    PubMed

    Ji, Young-Min; Jeon, Soung Hoo; Park, Joo-Young; Chung, Jong-Hoon; Choung, Yun-Hoon; Choung, Pill-Hoon

    2010-06-01

    Calcium hydroxide has been extensively and steadily used for direct pulp capping in modern clinical dentistry. As it was known to have potential to induce hard tissue repair, this chemical has been applied to the exposed dental pulp and the hard tissue is expected to be regenerated above the pulp. During the reparative process of exposed pulp, primary odontoblasts that were lost as a result of extensive damage are replaced with newly differentiated odontoblast-like cells. This process is known to follow the sequential steps of proliferation, migration, and differentiation of progenitor cells. This research will examine the relationship between calcium hydroxide and the recruitment, proliferation, and mineralization of postnatal dental stem cells, obtained from an immature dental tissue of beagle dogs. Immunocytochemical staining and reverse transcriptase-polymerase chain reaction were used to identify the putative stem cell markers. Immunoblot analysis, wound healing assay, cell migration assay, and alizarin red staining were used to evaluate proliferation, migration, and mineralization capacity of the calcium hydroxide-treated stem cells. As an in vivo study, a combination of calcium hydroxide and autologous dental pulp stem cells (DPSCs) was applied for the treatment of intentionally created tooth defects on the premolars and the molars in beagle dogs to observe dentin regeneration. Ex vivo expanded DPSCs and periodontal ligament stem cells expressed STRO-1 and CD146, the mesenchymal stem cell markers. It was evident that calcium hydroxide increased recruitment, migration, proliferation, and mineralization of the DPSCs and periodontal ligament stem cells. Such results are valuable for future availability of DPSCs, which are recently focused as the stem cell reservoir for regeneration of dentin upon tooth injury, as well as for elucidation of the role of calcium hydroxide in pulp capping therapy.

  2. Influence of calcium hydroxide on the post-treatment pain in Endodontics: A systematic review

    PubMed Central

    Anjaneyulu, K.; Nivedhitha, Malli Sureshbabu

    2014-01-01

    Introduction: Pain of endodontic origin has been a major concern to the patients and the clinicians for many years. Post-operative pain is associated with inflammation in the periradicular tissues caused by irritants egressing from root canal during treatment. It has been suggested that calcium hydroxide intra-canal medicament has pain-preventive properties because of its anti-microbial or tissue altering effects. Some dispute this and reasoned that calcium hydroxide may initiate or increase pain by inducing or increasing inflammation. Objective: To evaluate the effectiveness of calcium hydroxide in reducing the post-treatment pain when used as an intra-canal medicament Materials and Methods: The following databases were searched: PubMed CENTRAL (until July 2013), MEDLINE, and Cochrane Database of Systematic Reviews. Bibliographies of clinical studies and reviews identified in the electronic search were analyzed for studies published outside the electronically searched journals. The primary outcome measure was to evaluate the post-treatment pain reduction when calcium hydroxide is used as an intra-canal medicament in patients undergoing root canal therapy. Results: The reviews found some clinical evidence that calcium hydroxide is not very effective in reducing post-treatment pain when it is used alone, but its effectiveness can be increased when used in combination with other medicaments like chlorhexidine and camphorated monochlorophenol (CMCP). Conclusion: Even though calcium hydroxide is one of the most widely used intra-canal medicament due to its anti-microbial properties, there is no clear evidence of its effect on the post-treatment pain after the chemo-mechanical root canal preparation. PMID:24944439

  3. Calcium silicate and calcium hydroxide materials for pulp capping: biointeractivity, porosity, solubility and bioactivity of current formulations.

    PubMed

    Gandolfi, Maria Giovanna; Siboni, Francesco; Botero, Tatiana; Bossù, Maurizio; Riccitiello, Francesco; Prati, Carlo

    2015-01-01

    The chemical-physical properties of novel and long-standing calcium silicate cements versus conventional pulp capping calcium hydroxide biomaterials were compared. Calcium hydroxide-based (Calxyl, Dycal, Life, Lime-Lite) and calcium silicate-based (ProRoot MTA, MTA Angelus, MTA Plus, Biodentine, Tech Biosealer capping, TheraCal) biomaterials were examined. Calcium and hydroxyl ion release, water sorption, interconnected open pores, apparent porosity, solubility and apatite-forming ability in simulated body fluid were evaluated. All calcium silicate materials released more calcium. Tech Biosealer capping, MTA Plus gel and Biodentine showed the highest values of calcium release, while Lime-Lite the lowest. All the materials showed alkalizing activity except for Life and Lime-Lite. Calcium silicate materials showed high porosity values: Tech Biosealer capping, MTA Plus gel and MTA Angelus showed the highest values of porosity, water sorption and solubility, while TheraCal the lowest. The solubility of water-containing materials was higher and correlated with the liquid-to-powder ratio. Calcium phosphate (CaP) deposits were noted on materials surfaces after short aging times. Scant deposits were detected on Lime-Lite. A CaP coating composed of spherulites was detected on all calcium silicate materials and Dycal after 28 days. The thickness, continuity and Ca/P ratio differed markedly among the materials. MTA Plus showed the thickest coating, ProRoot MTA showed large spherulitic deposits, while TheraCal presented very small dense spherulites. calcium silicate-based cements are biointeractive (ion-releasing) bioactive (apatite-forming) functional biomaterials. The high rate of calcium release and the fast formation of apatite may well explain the role of calcium silicate biomaterials as scaffold to induce new dentin bridge formation and clinical healing.

  4. Effect of calcium hydroxide and endodontic irrigants on fibre post bond strength to root canal dentine.

    PubMed

    Renovato, S R; Santana, F R; Ferreira, J M; Souza, J B; Soares, C J; Estrela, C

    2013-08-01

    To analyse the effect of calcium hydroxide paste, endodontic irrigants and time of application on the bond strength of fibre posts to root canal dentine. Seventy bovine incisors were divided into 7 groups according to removal of calcium hydroxide and distilled water (CHW) (immediate - I; 21 days - 21 days; 6 months - 6 months) and endodontic irrigant (1% sodium hypochlorite - SH; 1% sodium hypochlorite + 17% EDTA - SHE). Fibre posts were cemented (RelyX U100), after which the roots were serially sectioned and submitted to a micro-push-out test. Data were analysed using two-way anova followed by the Tukey's and the Dunnett's tests (α = 0.05). The CHW groups were not significantly different from the control group in 13 of the 18 associated factors (P > 0.05). There were significant reductions in bond strength in the cervical (P = 0.0216) and middle (P = 0.0017) thirds of the root at 6 months in groups irrigated with SH. Irrigation with SHE reduced the bond strength significantly in the middle (P = 0.0488) and apical (P = 0.0252) thirds of the roots in the immediate groups and in the middle third (P = 0.0287) in the 21-day group. Bond strength was greater in the cervical than in the apical thirds of all immediate and 21-day groups (P < 0.05). Bond strength of groups that received CH paste was similar to that found in the control group in 13 of the 18 associated factors. EDTA and SH reduced bond strength in specimens in the immediate (middle and apical thirds) and 21-day (middle third) groups. There was a significant reduction in bond strength in the groups irrigated with SH and tested at 6 months (cervical and middle thirds). There was a predominance of adhesive failures between resin cement and dentine in all groups. © 2012 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  5. Carbonation as a binding mechanism for coal/calcium hydroxide pellets. Technical report, September 1, 1991--November 30, 1991

    SciTech Connect

    Rapp, D.M.

    1991-12-31

    Current coal mining and processing procedures produce a significant quanity of fine coal that is difficult to handle and transport. The objective of this work is to determine if these fines can be economically pelletized with calcium hydroxide, a sulfur capturing sorbent, to produce a clean-burning fuel for fluidized-bed combustors or stoker boilers. To harden these pellets, carbonation, which is the reaction of calcium hydroxide with carbon dioxide to produce a cementitious matrix of calcium carbonate, is being investigated. Previous research indicated that carbonation significantly improved compressive strength, impact and attrition resistance and ``weatherproofed`` pellets formed with sufficient calcium hydroxide (5 to 10% for minus 28 mesh coal fines).

  6. Ion Association versus Ion Interaction Models in Examining Electrolyte Solutions: Application to Calcium Hydroxide Solubility Equilibrium

    ERIC Educational Resources Information Center

    Menéndez, M. Isabel; Borge, Javier

    2014-01-01

    The heterogeneous equilibrium of the solubility of calcium hydroxide in water is used to predict both its solubility product from solubility and solubility values from solubility product when inert salts, in any concentration, are present. Accepting the necessity of including activity coefficients to treat the saturated solution of calcium…

  7. 75 FR 28608 - Calcium Hydroxide; Receipt of Application for Emergency Exemption, Solicitation of Public Comment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-21

    .../floors, and perimeters of commercial nurseries to control Eleutherodactylus frogs. The applicant proposes... nurseries to control Eleutherodactylus frogs. Information in accordance with 40 CFR part 166 was submitted... calcium hydroxide is necessary to control the tropical frogs, Eleutherodactylus coqui and E. planirostris...

  8. Ion Association versus Ion Interaction Models in Examining Electrolyte Solutions: Application to Calcium Hydroxide Solubility Equilibrium

    ERIC Educational Resources Information Center

    Menéndez, M. Isabel; Borge, Javier

    2014-01-01

    The heterogeneous equilibrium of the solubility of calcium hydroxide in water is used to predict both its solubility product from solubility and solubility values from solubility product when inert salts, in any concentration, are present. Accepting the necessity of including activity coefficients to treat the saturated solution of calcium…

  9. Effect of calcium hydroxide on ph changes of the external medium after intracoronal bleaching.

    PubMed

    Sa, Patricia Marra de; Jeronymo, Raffaela Di Iorio; Yui, Karen Cristina Kazue; Silva, Eduardo Galera da; Huhtala, Maria Filomena Rocha Lima; Torres, Carlos Rocha Gomes; Gomes, Ana Paula Martins

    2011-05-01

    This in vitro study evaluated the effect of calcium hydroxide on pH changes of the external medium after intracoronal bleaching. A total of 50 extracted human premolars were prepared and filled with gutta-percha and endodontic sealer. The teeth were randomly divided into five groups according to the bleaching agents employed: (a) Sterile cotton pellet with distilled water (control group); (b) sodium perborate and distilled water; (c) sodium perborate and 10% carbamide peroxide; (d) sodium perborate and 35% hydrogen peroxide; (e) 35% hydrogen peroxide. The teeth were stored in vials containing distilled water and the pH values of the medium surrounding the teeth were analyzed. After 7-day storage, the bleaching agent was removed and replaced by calcium hydroxide, and the distilled water was changed, in which the teeth were kept stored for further 14 days. Measurement of pH of the external medium (distilled water) was performed 7 days after insertion of the bleaching agents, immediately, 7 and 14 days after insertion of the calcium hydroxide. Data were submitted to statistical analysis by the two-way ANOVA and Tukey,s test. There were pH changes of the external medium at 7- day period after bleaching procedures. These results confirmed the diffusion of bleaching agents to the external medium. Calcium hydroxide increased the external medium pH and was effective for pH alkalinization after intracoronal bleaching. Intracoronal bleaching of endodontically treated teeth may cause cervical root resorption. A possible explanation for this process is the passage of bleaching agents to the periodontal tissues yielding an inflammatory process. In an attempt to keep the neutrality of the periodontal pH, the calcium hydroxide has been recommended.Results of this study showed that this material should be always used after intracoronal bleaching.

  10. Solid state and solution 43Ca NMR of calcium peroxides involved in the disproportionation of hydrogen peroxide by calcium hydroxide.

    PubMed

    Trokiner, Arlette; Bessière, Aurélie; Thouvenot, René; Hau, Damien; Marko, Jean; Nardello, Véronique; Pierlot, Christel; Aubry, Jean-Marie

    2004-06-01

    In order to get some insight into the mechanism of the disproportionation of hydrogen peroxide catalyzed by calcium hydroxide, 43Ca NMR spectra of enriched samples of calcium peroxides and of their precursors have been studied in both solution and solid state. This study demonstrates that no well-defined peroxidized calcium species are formed in solution, showing that the catalytic role of calcium is likely restricted to the solid state. Most of the calcium compounds that could be involved in the catalytic process have been investigated with solid state NMR. The shift and quadrupolar parameters of Ca(OH)2, CaO2.8H2O and CaO2.2H2O2 are reported for the first time. These parameters are different enough to allow the quantitative analysis of a complex mixture of these compounds by NMR.

  11. Study of the chemical mechanisms of the reaction of neutralization of calcium hydroxide by phosphoric acid

    NASA Astrophysics Data System (ADS)

    Elgadi, M.; Mejdoubi, E.; Elansari, L. L.; Essaddek, A.; Abouricha, S.; Lamhamdi, A.

    2005-03-01

    Calcium phosphates reported in this study, are prepared following an acido-basic reaction between phosphoric acid and calcium hydroxide. These phosphates are the brushite, tricalcium phosphate, hydroxyapatite and oxygenated apatite. The follow-up of the reaction by infra-red spectroscopy of absorption showed that the alkaline pH of calcium hydroxide solution, favours the formation of carbonated apatite, at the start of the reaction. Following the addition of phosphoric acid, the pH becomes increasingly favourable to the formation of the desired phase. The insertion of molecular oxygen in the apatitic tunnel is carried out by the use of hydrogen peroxide. The molecular oxygen rate in the apatite is then determined by volumetric analysis.

  12. Effect of calcium hydroxide premedication on the marginal adaptation of calcium-enriched mixture cement apical plug

    PubMed Central

    Bidar, Maryam; Disfani, Reza; Asgary, Saeed; Forghani, Maryam; Gharagozlo, Salman; Rouhani, Armita

    2012-01-01

    Background: This study was to evaluate the effects of calcium hydroxide premedication on the marginal adaptation of the calcium-enriched mixture (CEM) cement as an apical plug. Materials and Methods: In this in vitro study, forty single rooted teeth were prepared and apical portion of the roots were immersed in sulfuric acid to produce open apices. The teeth were divided into 2 experimental groups. In medicated group, calcium hydroxide was placed in all canals for 1 week and in non-medicated group no dressing was used. Then, a 4-mm apical plug of CEM cement was placed in canals; each root was prepared for observation using scanning electron microscope and the maximum distance between CEM cement and surrounding dentin was measured. The data were analyzed by t-test, and significance level was set at α = 0.05. Results: The mean width of gap in medicated and non-medicated groups was 158/1 μm and 147/1 μm, respectively. There was no significant difference between the two groups (P > 0.05). Conclusion: Calcium hydroxide premedication had no adverse effect on the marginal adaptation of CEM cement apical plug. PMID:23559945

  13. Effect of Calcium Hydroxide, Chlorhexidine Digluconate and Camphorated Monochlorophenol on the Sealing Ability of Biodentine Apical Plug

    PubMed Central

    Srivastava, Harshit; Prasad, Ashwini B; Raisingani, Deepak; Soni, Dileep

    2016-01-01

    Introduction Teeth with immature apex are managed by establishing an apical plug using various materials and techniques. However, the use of previously placed intracanal medicament may affect the sealing ability of permanent filling material used as an apical plug. Aim To evaluate the effect of removal of previously placed Calcium Hydroxide, Chlorhexidine Digluconate and Camphorated Monochlorophenol as an intracanal medicament on the sealing ability of the Biodentine as an apical plug. Materials and Methods A total of 72 recently extracted human permanent teeth with single root were selected and stored in saline at room temperature. The crown portion of each tooth was removed at the level of cemento enamel junction; 14mm root length was taken as standard length. All the roots were submerged in 20% sulphuric acid up to 3 mm from the apex, for four days for root resorption. One sample was cut longitudinally to look for root resorption under stereo microscope. The canal preparation was done; the roots were kept in moist gauze after instrumentation. A total of 71 roots were randomly divided into three groups. GROUP 1:Calcium hydroxide paste, GROUP 2: Chlorhexidine digluconate, GROUP 3: Camphorated Monochlorophenol (CMCP). The medicaments were removed with stainless steel hand files and 0.5% sodium hypochlorite irrigation. After removal of medicament Biodentine was placed in apical third of resorbed roots and the remaining portion of the canals was filled with gutta-percha. All the 71 roots were analysed with fluid filtration method for evaluating microleakage. Results Comparing all the three groups statistically there was no significant difference. The mean values were found more for group 1 followed by group 2 & 3. Conclusion All the groups showed microleakage. Calcium hydroxide showed the maximum microleakage followed by Chlorhexidine digluconate and least with CMCP. PMID:27504409

  14. Pore size distribution, strength, and microstructure of portland cement paste containing metal hydroxide waste

    SciTech Connect

    Majid, Z.A.; Mahmud, H.; Shaaban, M.G.

    1996-12-31

    Stabilization/solidification of hazardous wastes is used to convert hazardous metal hydroxide waste sludge into a solid mass with better handling properties. This study investigated the pore size development of ordinary portland cement pastes containing metal hydroxide waste sludge and rice husk ash using mercury intrusion porosimetry. The effects of acre and the addition of rice husk ash on pore size development and strength were studied. It was found that the pore structures of mixes changed significantly with curing acre. The pore size shifted from 1,204 to 324 {angstrom} for 3-day old cement paste, and from 956 to 263 {angstrom} for a 7-day old sample. A reduction in pore size distribution for different curing ages was also observed in the other mixtures. From this limited study, no conclusion could be made as to any correlation between strength development and porosity. 10 refs., 6 figs., 3 tabs.

  15. Efficacy of XP-endo Finisher File in Removing Calcium Hydroxide from Simulated Internal Resorption Cavity.

    PubMed

    Keskin, Cangül; Sariyilmaz, Evren; Sariyilmaz, Öznur

    2017-01-01

    The aim of this study was to evaluate the effect of supplementary use of XP-endo Finisher file, passive ultrasonic activation (PUI), EndoActivator (EA), and CanalBrush (CB) on the removal of calcium hydroxide (CH) paste from simulated internal resorption cavities. The root canals of 110 extracted single-rooted teeth with straight canals were prepared up to size 50. The specimens were split longitudinally, and standardized internal resorption cavities were prepared with burs. The cavities and root canals were filled with CH paste. The specimens were divided into 5 groups as follows: XP-endo Finisher, EA, PUI, CB, and syringe irrigation (SI). The root canals were irrigated with 5.25% NaOCl and 17% EDTA for 2 minutes, respectively. Apart from the SI group, both solutions were activated by using tested techniques for 1 minute. The quantity of CH remnants on resorption cavities was scored. Data were analyzed by using Kruskal-Wallis H and Mann-Whitney U tests. XP-endo Finisher and PUI removed significantly more CH than SI, EA, and CB (P < .05), showing no significant difference between them (P > .05). Differences among SI, EA, and CB were also non-significant (P > .05). None of the tested techniques render the simulated internal resorption cavities free of CH debris. XP-endo Finisher and PUI were superior to SI, CB, and EA. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  16. The effectiveness of mineral trioxide aggregate, calcium hydroxide and formocresol for pulpotomies in primary teeth.

    PubMed

    Moretti, A B S; Sakai, V T; Oliveira, T M; Fornetti, A P C; Santos, C F; Machado, M A A M; Abdo, R C C

    2008-07-01

    To compare the effectiveness of mineral trioxide aggregate (MTA), calcium hydroxide (CH) and formocresol (FC) as pulp dressing agents in carious primary teeth. Forty-five primary mandibular molars with dental caries in 23 children [AUTHOR QUERY: How many children?] between 5 and 9 years old were treated by a conventional pulpotomy technique. The teeth were randomly assigned to the experimental (CH or MTA) or control (FC) groups. After coronal pulp removal and haemostasis, remaining pulp tissue was covered with MTA paste or CH powder in the experimental groups. In the control group, diluted FC was placed with a cotton pellet over the pulp tissue for 5 min and removed; the pulp tissue was then covered with zinc oxide-eugenol (ZOE) paste. All teeth were restored with reinforced ZOE base and resin modified glass-ionomer cement. Clinical and radiographic successes and failures were recorded at 3, 6, 12, 18 and 24 month follow-up. Forty-three teeth were available for follow-up. In the FC and MTA groups, 100% of the available teeth were clinically and radiographically successful at all follow-up appointments; dentine bridge formation could be detected in 29% of the teeth treated with MTA. In the CH group, 64% of the teeth presented clinical and radiographic failures detected throughout the follow-up period, and internal resorption was a frequent radiographic finding. Mineral trioxide aggregate was superior to CH and equally as effective as FC as a pulpotomy dressing in primary mandibular molars. Internal resorption was the most common radiographic finding up to 24 month after pulpotomies performed with CH.

  17. An In-vitro Evaluation of the pH Change Through Root Dentin Using Different Calcium Hydroxide Preparations as an Intracanal Medicament

    PubMed Central

    Manjunath, M.K.; Tejaswi, Sunil

    2014-01-01

    Context: The aim of the study was to evaluate the pH variation in the surrounding medium after the use of two different vehicles of Calcium hydroxide – Saline (aqueous), Propylene glycol (viscous) and Calcium hydroxide containing guttapercha points over a period of 7 days as an intracanal medicament. Materials and Methods: Sixty single rooted premolars were decoronated at the cementoenamel junction and cleaned and shaped uptil size 40 master apical file. External defects were made on the mesial surface in the coronal third of the roots and divided randomly into 4 groups. One control and three experimental. In the control - group I the root canals were left empty. In the experimental groups - group II was filled with Ca(OH)2 + saline, group III was filled with Ca(OH)2 + propylene glycol and group IV the root canals were filled with Calcium hydroxide points. The coronal accesses were sealed with 3mm of Cavit G and all the surfaces of the root except the defect were covered with 3 coats at Nail varnish. The samples were then placed in air tight vials containing 2ml of distilled water. The vials were kept in an incubator and the pH of the surrounding medium was measured using a digital pH meter after 1,3,5 and 7 days respectively. Results: A statistically significant difference (p<0.05) existed between the experimental groups over the observation period. At day 1, a high pH was recorded by the calcium hydroxide points and saline groups and a lower pH by the propylene group. At day’s 3 and 5, the maximum pH was recorded by the propylene glycol group and minimum by the calcium hydroxide points and saline groups. At day 7, the pH of all the groups had dropped, with propylene glycol recording the maximum pH followed by saline and lastly calcium hydroxide points. Conclusion: Within the limitations of this study, a viscous vehicle is better among other vehicles, calcium hydroxide paste of propylene glycol provided the highest 7 days release of hydroxyl ions. PMID

  18. Carbonation as a binding mechanism for coal/calcium hydroxide pellets. [Quarterly] technical report, March 1, 1993--May 31, 1993

    SciTech Connect

    Lytle, J.; Hackley, K.; Dagamac, M.; Berger, R.; Schanche, G.

    1993-09-01

    This research is an investigation of calcium hydroxide, a sulfur-capturing sorbent, as a binder for coal fines. The reaction of carbon dioxide with calcium hydroxide, referred to as carbonation, is being studied as a method of improving pellet quality. Carbonation forms a cementitious matrix of calcium carbonate. The effect of particle size and compaction pressure on pellet strength was studied using a laboratory hydraulic press. Particle distributions with mean sizes of 200, 90 and 40 microns were tested. The results indicate that pellet strength increased with decreasing particle size and increasing compaction pressure when calcium hydroxide was used as a binder. Pellets containing 10 wt% calcium hydroxide increased in strength by approximately 40% when air dried for one day. This increase in strength is attributed to carbonation of the calcium hydroxide via atmospheric carbon dioxide. Corn starch, an adhesive binder, was tested at the finest particle size. Pellet strength did not increase as a function of increasing compaction pressure. At the finest particle size and highest compaction pressure (18,750 psi), dried pellets formed with 2 wt% corn starch were equivalent in strength to pellets containing 5 wt% calcium hydroxide.

  19. Comparative in vitro investigation of different methods for temporary root canal filling with aqueous suspensions of calcium hydroxide.

    PubMed

    Staehle, H J; Thomä, C; Müller, H P

    1997-06-01

    Three methods for temporarily filling root canals with calcium hydroxide pastes were compared. Each of 20 root canals of extracted, human, single-rooted teeth was shaped with hand instruments under standardized conditions up to ISO size 50 and filled using a syringe system, a lentulo spiral or an endodontic reamer. Quality of fillings was assessed radiographically and by inspecting ground preparations. Ridit (relative to an identified distribution) analysis was employed to confirm differences in frequencies of certain quality criteria obtained with various application methods. With regard to degree of obturation and occurrence of porosities, application of temporary fillings with a lentulo spiral or syringe system revealed significantly better results than application with hand instruments (reamer). No differences with regard to degree of obturation were detected when comparing results obtained with syringe or lentulo. Fewer porosities in the apical part of the root canal were seen, both on radiographs and ground sections, with the syringe system compared with the lentulo spiral. In the presence of some contradictory reports found in the literature, the present study suggests that, after straight or slightly curved root canals have been shaped up to at least ISO size 50, high quality temporary root canal fillings may be obtained by application of an aqueous suspension of calcium hydroxide with a syringe system.

  20. Alcohol dispersions of calcium hydroxide nanoparticles for stone conservation.

    PubMed

    Rodriguez-Navarro, Carlos; Suzuki, Amelia; Ruiz-Agudo, Encarnacion

    2013-09-10

    Alcohol dispersions of Ca(OH)2 nanoparticles, the so-called nanolimes, are emerging as an effective conservation material for the consolidation of stone, mortars, and plasters present in old masonry and/or mural paintings. To better understand how this treatment operates, to optimize its performance and broaden its applications, here we study the nano and microstructural characteristics, carbonation behavior, and consolidation efficacy of colloidal alcohol dispersions of Ca(OH)2 nanoparticles produced by both homogeneous (commercial nanolime) and heterogeneous phase synthesis (aged slaked lime and carbide lime putties). We observe that the alcohol not only provides a high colloidal stability to Ca(OH)2 particles, but also affects the kinetics of carbonation and CaCO3 polymorph selection. This is due to the pseudomorphic replacement of Ca(OH)2 particles by calcium alkoxides upon reaction with ethanol or 2-propanol. The extent of this replacement reaction depends on Ca(OH)2 size and time. Hydrolysis of alkoxides speeds up the carbonation process and increases the CaCO3 yield. The higher degree of transformation into calcium alkoxide of both the commercial nanolime and the carbide lime fosters metastable vaterite formation, while calcite precipitation is promoted upon carbonation of the aged slaked lime due its lower reactivity, which limits calcium alkoxide formation. A higher consolidation efficacy in terms of strength gain of treated porous stone is achieved in the latter case, despite the fact that the carbonation is much faster and reaches a higher yield in the former ones. Formation of alkoxides, which has been neglected in previous studies, needs to be considered when applying nanolime treatments. These results show that the use Ca(OH)2 nanoparticle dispersions prepared with either aged slaked lime or carbide lime putties is an economical and effective conservation alternative to commercial nanolimes produced by homogeneous phase synthesis. Ultimately, this

  1. Apexogenesis of a symptomatic mandibular first permanent molar with calcium hydroxide pulpotomy.

    PubMed

    Kontham, Ujwal R; Tiku, Amita M; Damle, Satyawan G; Kalaskar, Ritesh R

    2005-09-01

    Vital pulp therapy of immature, symptomatic permanent posterior teeth presents a challenge in pediatric endodontics. A case report is presented in which cervical pulpotomy with calcium hydroxide was performed on a cariously exposed mandibular first permanent molar. The patient was seen every 3 months for a total of 18 months for a clinical and radiographic follow up. During the follow-up period, root development, as evidenced by root lengthening, was observed. Apical closure was evident at the end of 19 months. As the root canals showed a tendency toward calcification, root canal treatment was carried out, followed by restoration of the tooth with a stainless-steel crown. The success of this single-visit apexogenesis procedure supports the contention that young pulp possesses remarkable reparative capacity, as well as resistance to bacterial infection due to greater vascularity, and that apexogenesis with calcium hydroxide apical closure pulpotomy can be attempted for continued root development of symptomatic, vital, permanent teeth.

  2. Comparison of different irrigants on calcium hydroxide medication removal: microscopic cleanliness evaluation.

    PubMed

    Salgado, Ricardo Julio Cabrales; Moura-Netto, Cacio; Yamazaki, Andrea Kanako; Cardoso, Luciano Natividade; de Moura, Abílio Albuquerque Maranhão; Prokopowitsch, Igor

    2009-04-01

    Calcium hydroxide dressing residuals can compromise endodontic sealing. This study evaluated the cleaning efficacy of different endodontic irrigants in removing calcium hydroxide by SEM image analysis. Fifty-four single-rooted mandibular premolars were instrumented to a master apical file #60 and dressed with calcium hydroxide. After 36 hours, the teeth were reopened and Ca(OH)(2) medication was removed by 5 different experimental groups: 0.5% NaOCl (G1), EDTA-C (G2), citric acid (G3), EDTA-T (G4), and re-instrumentation with MAF using NaOCl and lubrificant, followed by EDTA-T (G5). The roots were split in the buccal-lingual direction and prepared for SEM analysis in cervical, middle, and apical thirds (9, 6, and 3mm from the apex). Five blinded examiners evaluated the wall cleanliness using a scale from 1 to 5. Statistical analysis was performed using Kruskal-Wallis at 5% level of significance. Group G5 had the best results in all thirds, with significant statistical differences compared to all other groups in the middle and coronal third, and to G1 in the apical third. On the other hand, G1, only flushed with NaOCl, had the worst results, with statistical differences in all thirds compared to the other groups. The best cleanliness was achieved by G4 and G5 groups. The recapitulation of MAF in combination with irrigants improved the removal of calcium hydroxide medication better than an irrigant flush alone.

  3. Efficacy of different irrigants in the removal of calcium hydroxide from root canals.

    PubMed

    Rödig, T; Vogel, S; Zapf, A; Hülsmann, M

    2010-06-01

    To compare the efficacy of different solutions (1% sodium hypochlorite, 10% citric acid and 20% EDTA) in the removal of calcium hydroxide from root canals. One hundred single-rooted maxillary incisors were prepared to size 50 and split longitudinally. Two standardized grooves were cut into the apical and coronal part of the root canal dentine and filled with calcium hydroxide. The reassembled teeth were irrigated with a syringe and a size 30 needle using the following irrigants: (i) 20% EDTA, (ii) 10% citric acid, (iii) 1% NaOCl, (iv) 10% citric acid + 1% NaOCl, (v) 20% EDTA + 1% NaOCl and (vi) water (control). Volume of irrigant was 20 mL in each group, and irrigation time was 5 min. Evaluation of cleanliness of the blinded specimens was performed by two calibrated observers under a microscope with 30x magnification using a four-grade scoring system as described by van der Sluis et al. (2007). Statistical evaluation was performed using a SAS-macro for non-parametric multifactorial analysis (P < 0.05). The best results were found for irrigation with EDTA and citric acid, whereas NaOCl and water showed the least effect. The combinations of irrigants did not result in improvement in terms of cleanliness. None of the irrigants nor their respective combinations were able to completely remove the calcium hydroxide. Chelating agents such as citric acid and EDTA showed the best results. The combination of chelators and NaOCl did not result in significant improvement of calcium hydroxide removal.

  4. Nanoparticles for cultural heritage conservation: calcium and barium hydroxide nanoparticles for wall painting consolidation.

    PubMed

    Giorgi, Rodorico; Ambrosi, Moira; Toccafondi, Nicola; Baglioni, Piero

    2010-08-16

    Nanotechnology provides new concepts and materials for the consolidation and protection of wall paintings. In particular, humble calcium and barium hydroxide nanoparticles offer a versatile and highly efficient tool to combat the main degradation processes altering wall paintings. Clear example of the efficacy and potentiality of nanotechnology is represented by the conservation in situ of Maya wall paintings in the archaeological area in Calakmul (Mexico).

  5. Tecidual Reaction of Calcium Hydroxide Front Chronic Stress Histological Study in Rats

    PubMed Central

    Semenoff, Tereza Aparecida Delle Vedove; Vieira, Evanice Menezes Marçal; Borges, Álvaro Henrique; Bandeca, Matheus Coelho; dos Santos, Reidson Stanley Soares; Pedro, Fábio Luis Miranda; da Silva, Natalino Francisco; Semenoff-Segundo, Alex

    2014-01-01

    Background: The Calcium Hydroxide has been widely used as an intracanal dressing and in combination with restorative and endodontic materials and its main goal is the tissue reparation. However, when the patient has chronic stress, the immunological response and tissue repair decreases in both the epithelial and connective tissue. Therefore, the aim was to analyze the effect of chronic stress on the tissue response in rats exposed to calcium hydroxide (CH). Materials and Methods: A total of 60 wistar rats were anesthetized, and a polyethylene tube containing CH was inserted under the skin. After 24 h, they were divided into two groups: Calcium hydroxide + stress (CHSG) n = 30 and calcium hydroxide (CHG) n = 30. They were stressed by physical restraint, for 12 h each day for periods of 7, 15 and 30 days when 10 animals from each group were euthanized. The tissues surrounding the polyethylene tubes were removed, and slides were prepared and stained with hematoxylin and eosin. The analysis was performed with an optical microscope with magnification of 4-400 times by a blinded senior examiner. The sample slides were classified according to the following scores 0 - absent/1 - present/2 - infiltrate to: Inflammatory infiltrate containing fibrous condensation, lymphocytes, plasmacytes, macrophages, neutrophils, and eosinophils. The data were statistically analyzed using the Student’s t-test (P < 0.05) for paired samples. Results: The exposure time of 7 days elicited no statistical difference between groups (P > 0.05). The 15 days exposure group had higher averages for CHG to eosinophils and inflammatory infiltrate (P < 0.05). In 30 days, CHG showed higher averages to inflammatory infiltrate and lower averages to FC (P < 0.05). Conclusions: Some modified patterns of responses in the CHSG were observed at 15 days and 30 days. PMID:25214724

  6. Comparison of the Penetration Depth of Conventional and Nano-Particle Calcium Hydroxide into Dentinal Tubules.

    PubMed

    Zand, Vahid; Mokhtari, Hadi; Hasani, Aila; Jabbari, Golchin

    2017-01-01

    The aim of this in vitro study was to evaluate and compare the penetration depth of conventional (CH) and nano-particle calcium hydroxide (NCH) into dentinal tubules. Ninety human single-rooted teeth were instrumented by RaCe rotary system and after chemomechanical preparation were randomly divided in two equal groups (n=45). In the first group conventional CH and in the other NCH was used as intracanal medicament. After 2 weeks of incubation all roots were intentionally split at longitudinal axis and prepared for scanning electron microscope (SEM) observation. Three zones of each root, coronal, middle and apical were examined under SEM and the maximum penetration depth of the dressing material into dentinal tubules was recorded for each zone. Data were analyzed using the independent sample t test and the level of significance was set at 0.05. In all of the three zones, NCH group had greater penetration depth than CH (P<0.001). In both groups the penetration depth increased from the apical section to the coronal. The depth of penetration of nano-particle calcium hydroxide into the dentinal tubules was significantly higher than that of conventional calcium hydroxide. The lowest penetration depth was observed in apical zone in both groups.

  7. In vitro evaluation of pH changes induced by calcium hydroxide liners.

    PubMed

    Gençay, Koray; Seymen, Figen; Selvi, Senem; Kiziltan, Başak

    2004-01-01

    Since the highly alkaline pH of calcium hydroxide is considered by many to be responsible for its biologic activity, the possible variations of pH induced by the different calcium hydroxide liners are accepted as a major concern. The aim of the present study was to determine the pH changes of five different calcium hydroxide liners and variations of pH levels at different time intervals. The materials tested were Dycal, Life, Calic, Dycal VLC, and Calcident 450. Samples were prepared according to manufacturer instructions and by using plastic molds; five standard samples from each material were prepared. The samples were then placed in separate vials, containing 10 mL deionized water (pH 7.0), and stored at room temperature (200C). The pH measurements were taken 1 hour, 24 hours, 3 days, and 7 days after mixing. The pH variations of each material at the given time intervals were recorded, and the means were calculated. Statistical analysis showed significantly high differences between the mean pH values induced by each material at all time intervals. The highest value for the first-hour measurement was for Dycal VLC, and the highest values for the other time intervals were for Calcident 450. The pH values of the materials exhibited statistically significant differences among all the time intervals. All materials changed the pH of deionized water toward alkaline.

  8. Efficacy of the NaviTip FX irrigation needle in removing calcium hydroxide from root canal

    PubMed Central

    Bramante, Clovis M.; Pinheiro, Bethânia C.; Garcia, Roberto B.; Bramante, Alexandre S.; Bernardineli, Norberti; de Moraes, Ivaldo G.; Húngaro-Duarte, Marco A.

    2012-01-01

    Objective: To evaluate the effectiveness of the NaviTip FX, brush-covered irrigation needle, in removing calcium hydroxide from the root canal. Study Design: Thirty single-rooted teeth were randomly divided into three groups: A - irrigation with a hypodermic needle inserted as far as possible without binding and activation with #30 K-type file; B - Irrigation with a hypodermic needle without activation; C - irrigation with NaviTip FX needle. Sodium hypoclorite 1% was used in irrigation. The root canals were examined trough scanning electron microscopy. Calcium hydroxide removal was recorded at 1, 5, and 10mm from the working length (WL) and the data were analysed using one-way ANOVA test (p<0.05). Results: NaviTip FX and hypodermic needle activated with #30K-type file showed lower score at 10 and 5mm with no significant difference between them. Comparison within groups did not show significant differences. All groups showed significantly better smear layer removal at 5 and 10 mm from the WL. Conclusion: The apical third (1mm) of the root canal was found to be the most critical site for Ca(OH)2 removal. Key words:Calcium hydroxide, irrigation, scanning electron microscope, NaviTip FX. PMID:24558560

  9. Efficacy of the NaviTip FX irrigation needle in removing calcium hydroxide from root canal.

    PubMed

    Bramante, Clovis M; Pinheiro, Bethânia C; Garcia, Roberto B; Bramante, Alexandre S; Bernardineli, Norberti; de Moraes, Ivaldo G; Húngaro-Duarte, Marco A; Pinheiro, Tiago N

    2012-10-01

    To evaluate the effectiveness of the NaviTip FX, brush-covered irrigation needle, in removing calcium hydroxide from the root canal. Thirty single-rooted teeth were randomly divided into three groups: A - irrigation with a hypodermic needle inserted as far as possible without binding and activation with #30 K-type file; B - Irrigation with a hypodermic needle without activation; C - irrigation with NaviTip FX needle. Sodium hypoclorite 1% was used in irrigation. The root canals were examined trough scanning electron microscopy. Calcium hydroxide removal was recorded at 1, 5, and 10mm from the working length (WL) and the data were analysed using one-way ANOVA test (p<0.05). NaviTip FX and hypodermic needle activated with #30K-type file showed lower score at 10 and 5mm with no significant difference between them. Comparison within groups did not show significant differences. All groups showed significantly better smear layer removal at 5 and 10 mm from the WL. The apical third (1mm) of the root canal was found to be the most critical site for Ca(OH)2 removal. Key words:Calcium hydroxide, irrigation, scanning electron microscope, NaviTip FX.

  10. Clinical outcome of direct pulp capping with MTA or calcium hydroxide: a systematic review and meta-analysis.

    PubMed

    Zhu, Chenxi; Ju, Bin; Ni, Rong

    2015-01-01

    Direct pulp capping is one of the most common dental practices in endodontic therapy. This systematic review and meta-analysis aim to determine whether the effect of mineral trioxide aggregate (MTA) and calcium hydroxide for direct pulp capping is different, as measured by the clinical and radiographic analysis. The study list was obtained by searching PubMed, Springer Link, Scopus and Cochrane Database. Only those papers that met the inclusion criteria were analyzed. The results indicated that four studies met the inclusion criteria. Statistically significant difference was found between the success rates of MTA and calcium hydroxide treated teeth that needed direct pulp capping (P=0.002). Clinical assessments of the MTA versus calcium hydroxide for direct pulp capping suggested that MTA was superior to calcium hydroxide in direct pulp capping resulting in a lower failure rate (risk difference 0.1 [95% CI 0.04 to 0.16]). In conclusion, MTA has a higher clinical success rate for direct pulp capping comparing to calcium hydroxide, and might be a suitable replacement for calcium hydroxide.

  11. Clinical outcome of direct pulp capping with MTA or calcium hydroxide: a systematic review and meta-analysis

    PubMed Central

    Zhu, Chenxi; Ju, Bin; Ni, Rong

    2015-01-01

    Direct pulp capping is one of the most common dental practices in endodontic therapy. This systematic review and meta-analysis aim to determine whether the effect of mineral trioxide aggregate (MTA) and calcium hydroxide for direct pulp capping is different, as measured by the clinical and radiographic analysis. The study list was obtained by searching PubMed, Springer Link, Scopus and Cochrane Database. Only those papers that met the inclusion criteria were analyzed. The results indicated that four studies met the inclusion criteria. Statistically significant difference was found between the success rates of MTA and calcium hydroxide treated teeth that needed direct pulp capping (P=0.002). Clinical assessments of the MTA versus calcium hydroxide for direct pulp capping suggested that MTA was superior to calcium hydroxide in direct pulp capping resulting in a lower failure rate (risk difference 0.1 [95% CI 0.04 to 0.16]). In conclusion, MTA has a higher clinical success rate for direct pulp capping comparing to calcium hydroxide, and might be a suitable replacement for calcium hydroxide. PMID:26770296

  12. Influence of calcium hydroxide dressing and two irrigants on the filling of artificial lateral canals.

    PubMed

    Deonizio, Marili Doro Andrade; Teixeira, Betânia Drummond Duarte; Gabardo, Marilisa Carneiro Leão; Batista, Antonio; Kowalczuck, Alexandre; Sydney, Gilson Blitzkow

    2015-01-01

    This study was carried out on the assumption that calcium hydroxide [Ca(OH) 2 ] dressing and irrigants may influence the obturation of lateral canals. To evaluate the influence of 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX) gel and Ca(OH) 2 on the filling of artificial lateral canals. Ex vivo quantitative laboratory study. Forty-two human mandibular premolars were selected. After cavity access, six lateral canals were performed, two in each root section, one mesial and one on the distal root surface. After preparation, the specimens were randomly divided into four groups: Group I: Under irrigation with 2% CHX and saline solution and with intracanal dressing Ca(OH) 2 paste; Group II: The same preparation as Group I, but without Ca(OH) 2 ; Group III: Under irrigation with 2.5% NaOCl without Ca(OH) 2 ; and Group IV: The same preparation as Group III, but with Ca(OH) 2 . Two teeth without intracanal dressing were used as negative controls. Lateral condensation technique was performed. Then, digital radiographic images were obtained. Data were analyzed using SPSS 17.0, submitted to Kappa (reliability between examiners) and Kruskal-Wallis test. No statistical difference was registered between Groups II and III in all root sections (P > 0.05), but it was observed between Groups I and IV (P < 0.05), except on the apical section (P > 0.05). In all sections, the Group I filled more artificial lateral canals than in Group IV. The irrigants tested had no influence on the filling of artificial lateral canals. Nevertheless, intracanal dressing of Ca(OH) 2 influenced this filling.

  13. The effect of peracetic acid on removing calcium hydroxide from the root canals.

    PubMed

    Sağsen, Burak; Ustün, Yakup; Aslan, Tuğrul; Canakçi, Burhan Can

    2012-09-01

    The goal of this study was to evaluate the efficiencies of different irrigation solutions in the removal of calcium hydroxide (CH). Forty-eight maxillary central incisor teeth were used. Root canals were prepared with the ProTaper system (Dentsply Maillefer, Baillagues, Switzerland). Five milliliters 2% NaOCl, 5 mL 17% EDTA, and 10 mL saline were used for final irrigation. The canals were filled with CH paste. Specimens were randomly divided into 4 experimental groups (n = 10) according to irrigation protocols. Positive and negative control groups (n = 4) were used. Group 1 used 2.5 mL 17% EDTA, group 2 used 2.5 mL 2.5% NaOCl + 2.5 mL 17% EDTA, group 3 used 2.5 mL 1% peracetic acid (PAA), and group 4 used 2.5 mL 0.5% PAA. The specimens were evaluated with scanning electron microscope analysis and scored. Kruskal-Wallis and Student Newman-Keuls post hoc tests were used for statistical analysis. In the apical thirds, 1% PAA was superior to the other groups (P < .05); however, there were no significant differences among the other groups (P > .05). In the middle thirds, no significant differences were found among the groups (P > .05). In the coronal thirds, 1% PAA was superior to the other groups. There were significant differences among all the other groups (P < .05). According to the findings of the present study, 1% PAA could be recommended for the removal of CH from the root canals. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

  14. Exopolysaccharide dispelled by calcium hydroxide with volatile vehicles related to bactericidal effect for root canal medication

    PubMed Central

    Lei, Lei; Shao, Meiying; Yang, Yan; Mao, Mengying; Yang, Yingming; Hu, Tao

    2016-01-01

    ABSTRACT Objective: Enterococcus faecalis is the dominant microbial species responsible for persistent apical periodontitis with ability to deeply penetrate into the dentin. Exopolysaccharides (EPS) contribute to the pathogenicity and antibiotic resistance of E. faecalis. Our aim was to investigate the antimicrobial activity of calcium hydroxide (CH), camphorated parachlorophenol (CMCP), and chlorhexidine (CHX) against E. faecalis in dentinal tubules. Material and Methods: Decoronated single-canal human teeth and semicylindrical dentin blocks were incubated with E. faecalis for 3 weeks. Samples were randomly assigned to six medication groups for 1 week (n=10 per group): CH + 40% glycerin-water solution (1:1, wt/vol); CMCP; 2% CHX; CH + CMCP (1:1, wt/vol); CH + CMCP (2:3, wt/vol); and saline. Bacterial samples were collected and assayed for colony-forming units. After dentin blocks were split longitudinally, confocal laser scanning microscopy was used to assess the proportion of viable bacteria and EPS production in dentin. Results: CMCP exhibited the best antimicrobial activity, while CH was the least sensitive against E. faecalis (p<0.05). CHX showed similar antimicrobial properties to CH + CMCP (1:1, wt/vol) (p>0.05). CH combined with CMCP inhibited EPS synthesis by E. faecalis, which sensitized biofilms to antibacterial substances. Moreover, increasing concentrations of CMCP decreased EPS matrix formation, which effectively sensitized biofilms to disinfection agents. Conclusion: The EPS matrix dispelled by CH paste with CMCP may be related to its bactericidal effect; the visualization and analysis of EPS formation and microbial colonization in dentin may be a useful approach to verify medicaments for antimicrobial therapy. PMID:27812619

  15. Carbonation as a binding mechanism for coal/calcium hydroxide pellets. Final technical report, September 1, 1991--August 31, 1992

    SciTech Connect

    Rapp, D.M.; Lytle, J.M.; Hackley, K.C.; Strickland, R.; Berger, R.; Schanche, G.

    1992-12-31

    In this project, the ISGS is investigating the pelletization of fine coal with calcium hydroxide, a sulfur-capturing sorbent. The objective is to produce a readily-transportable fuel which will burn in compliance with the recently passed Clean Air Act Amendment (CAAA). To improve the economics of pelletizing, carbonation, or, the reaction of carbon dioxide with calcium hydroxide, which produces a binding matrix of calcium carbonate, is being investigated as a method of hardening pelletized coal fines. This year, pellets were produced from 28 {times} 0 coal fines collected from an Illinois preparation plant using a laboratory version of a California Pellet Mill (CPM), a commercially available pellet machine. The CPM effectively pelletized coal fines at the moisture content they were dewatered to at the plant. Carbonation nearly doubled the strength of pellets containing 10 wt % calcium hydroxide. Other results from this year`s work indicate that inclusion of calcium hydroxide into pellets resulted in chlorine capture of approximately 20 wt % for combustion tests conducted at both 850 and 1100{degrees}C. Arsenic emissions were reduced from near 38 wt% at 850 C to essentially nil with inclusion of 10 wt % calcium hydroxide into the pellets. At 110{degrees}C, arsenic emissions were reduced from about 90 wt % to about 15 wt %. Sodium emissions, however, increased with the addition of calcium hydroxide. At 850{degrees}C, sodium capture dropped from about 98 wt % to 73 wt % for pellets containing 10 wt % calcium hydroxide; at 1100{degrees}C, capture dropped from about 92 wt % to about 20 wt %.

  16. Residual antibacterial activity of chlorhexidine digluconate and camphorated p-monochlorophenol in calcium hydroxide-based root canal dressings.

    PubMed

    Soares, Janir Alves; Leonardo, Mario Roberto; Tanomaru Filho, Mário; Silva, Léa Assed Bezerra da; Ito, Izabel Yoko

    2007-01-01

    The purpose of this study was to evaluate the residual antibacterial activity of several calcium hydroxide [Ca(OH)2]-based pastes, placed in root canals of dogs' teeth with induced chronic periapical lesions. Root canals were instrumented with the ProFile rotary system and filled with 4 pastes: G1 (n=16): Ca(OH)2 paste + anesthetic solution; G2 (n=20): Calen paste + camphorated p-monochlorophenol (CMCP); G3 (n=18): Calen; and G4 (n=18): Ca(OH)2 paste + 2% chlorhexidine digluconate. After 21 days, the pastes were removed with size 60 K-files and placed on Petri plates with agar inoculated with Micrococcus luteus ATCC 9341. Pastes that were not placed into root canals served as control. After pre-diffusion, incubation and optimization, the inhibition zones of bacterial growth were measured and analyzed by Mann-Whitney U test at 5% significance level. All pastes showed residual antibacterial activity. The control samples had larger halos (p<0.05). The mean residual antibacterial activity halos in G1, G2, G3 and G4 were 7.6; 10.4; 17.7 and 21.4 mm, respectively. The zones of bacterial growth of G4 were significantly larger than those of G1 and G2 (p<0.05). In conclusion, regardless of the vehicle and antiseptic, all Ca(OH)2-based pastes showed different degrees of measurable residual antibacterial activity. Furthermore, unlike CMCP, chlorhexidine increased significantly the antibacterial activity of Ca(OH)2.

  17. [Calcium hydroxide and treatment of inflammatory inter-radicular bone resorption of non-vital deciduous molars].

    PubMed

    Charles, Pilipili; Nathalie, Senger; Carine, Defat; Alexandru, George

    2004-01-01

    On non-vital deciduous molars, inter-radicular bone resorption is often an indication of extraction. The endodontic treatment of these teeth by means of zinc oxide-eugenol (ZOE) paste also showed its limits. To mitigate the deficiencies of this material, we suggested a preliminary treatment by means of calcium hydroxide (Ca(OH)2) for its anti-inflammatory and antiseptic properties as well as its ability to stimulate calcified tissues apposition or remineralisation. This study concerns 21 non-vital deciduous molars. X-rays excluded any lesion of the underlying permanent bony crypt (bone tissue) as well as any inflammation of the dental follicle. After preparation, root canals were filled by means of Pulpdent. An initial X-ray check was made 15 days and then every 3 months. After disappearance of the inflammatory resorption, root canal fillings were performed with ZOE paste. The remineralisation of the inter-radicular alveolar bone was observed for 14 deciduous molars, which were then filled using ZOE. The remineralisation period varies from 3 to 18 months depending on the scale of the lesion. Of the 7 failed treatments, 3 failed following downfall of the crown filling material, and 2 due to failure to keep appointments and late replacement of resorbed Ca(OH)2. On 2 teeth, the treatment did not stop the lesion forming. Calcium hydroxide (Ca(OH)2) give encouraging results in the treatment of inter-radicular alveolar bone resorption of non-vital deciduous tooth. Its fast resorption requires rigorous controls, frequent refills, and thus strong motivation on the part of the child and parents. It cannot, on any account, be considered as permanent filling material.

  18. Electrochemical noise analysis of galvanized steel immersed in saturated calcium hydroxide solutions

    SciTech Connect

    Diaz-Ballote, L.; Garfias-Mesias, L.F.

    1999-08-01

    Steel (UNS G10400) was galvanized by using a commercial hot-dip galvanizing method. The coated steel was immersed in a saturated calcium hydroxide (Ca[OH]{sub 2}) solution (pH {approx} 12.4) and in a saturated Ca(OH){sub 2} + 0.5 M potassium hydroxide (KOH) solution (pH {approx} 13.4). The potential and current were measured simultaneously while the coated steel was kept immersed in the solution. The potential was measured against a saturated calomel electrode (SCE) and by using an electrometer. The current was measured between two identical samples using a zero resistance ammeter (ZRA). The relationship between the performance of the zinc coating and the noise information obtained was discussed. The electrochemical potential was found to be correlated to the corrosion rate of the coated steel. The current pattern and the standard deviation of the current was found to be well correlated with the corrosion rate.

  19. Sustained release of calcium hydroxide from poly(DL-lactide-co-glycolide) acid microspheres for apexification.

    PubMed

    Cerda-Cristerna, Bernardino Isaac; Breceda-Leija, Alejandro; Méndez-González, Verónica; Chavarría-Bolaños, Daniel; Flores-Reyes, Héctor; Garrocho-Rangel, Arturo; Komabayashi, Takashi; Wadajkar, Aniket S; Pozos-Guillén, Amaury J

    2016-09-01

    Calcium hydroxide (CH) loaded poly(DL-lactide-co-glycolide) acid (PLGA) microspheres (MS) might be used for apexification requiring a sustained release of Ca(2+). The aim of this study was to formulate and characterize CH-PLGA-MS. The CH-loaded MS were prepared by either oil-in-water (O/W) or water-in-oil/in-water (W/O/W) emulsion solvent evaporation technique. MS produced by the O/W technique exhibited a larger diameter (18.63 ± 7.23 μm) than the MS produced by the W/O/W technique (15.25 ± 7.37 μm) (Mann-Whitney U test P < 0.001). The CH encapsulation efficiency (E e) and Ca(2+) release were calculated from data obtained by absorption techniques. Ca(2+) release profile was evaluated for 30 days. To know the E e, the CH-loaded MS were dissolved in 1 M NaOH to release all its content and a Ca(2+) colorimetric marker was added to this solution. The reagent marked the Ca(2+) in blue color, which was then measured by a UV-Vis system (650 nm). The percentage of E e was calculated on the basis of the theoretical loading. The E e of the O/W-produced MS was higher (24 %) than the corresponding percentage of the W/O/W-produced MS (11 %). O/W- and W/O/W-produced MS released slower and lower Ca(2+) than a control CH paste with polyethylene glycol 400 (Kruskal-Wallis test). O/W-produced MS released higher Ca(2+) than W/O/W-produced MS (statistically significant differences; P < 0.05). In conclusion, the CH-PLGA-MS were successfully formulated; the technique of formulation influenced the size, encapsulation efficiency and release profile. The MS were better sustained release system than the CH paste.

  20. In vitro study of calcium hydroxide removal from mandibular molar root canals.

    PubMed

    Ma, Jingzhi; Shen, Ya; Yang, Yan; Gao, Yuan; Wan, Pan; Gan, Yan; Patel, Payal; Curtis, Allison; Khakpour, Mehrzad; Haapasalo, Markus

    2015-04-01

    Previous studies have shown the difficulty in removing calcium hydroxide (Ca[OH]2) paste from the root canals before root filling. Mesial and distal canals of 30 mandibular molars were prepared with the WaveOne Primary (25/.08) and Large file (40/.08) (Dentsply Tulsa Dental Specialties, Tulsa, OK), respectively. All canals were then filled with Ca(OH)2. The teeth were divided into the following 3 treatment groups (each with n = 10): (1) instrumentation with needle irrigation, (2) instrumentation with irrigation and passive ultrasonic activation (PUI), and (3) the GentleWave system (Sonendo, Inc, Laguna Hills, CA) without instrumentation. The irrigation time in each group was 7.5 minutes. To further test the efficiency of the GentleWave system, shorter times of 90 seconds were tested using water alone. Reconstructed micro-computed tomographic scans were used to measure the volume of the canals and Ca(OH)2 after instrumentation, initial filling of Ca(OH)2, and after its removal. The percentage of Ca(OH)2 remaining in the canals was calculated. None of the 10 teeth (30 canals) in the conventional irrigation and PUI groups were completely cleaned of Ca(OH)2 in 7.5 minutes. In the apical third of mesial and distal canals, respectively, conventional irrigation removed 47.82% ± 16.36% and 77.68% ± 12.82%, PUI removed 61.66% ± 25.54% and 88.85 ± 12.06%, and the GentleWave system removed significantly more Ca(OH)2 (P < .05) with 100% and 98.78% ± 3.84%. Additional experiments in 10 teeth, using only water as the irrigant, revealed that the GentleWave system removed 99.85% and 99.97% of Ca(OH)2 within 90 seconds without the use of any instruments in the mesial and distal canals, respectively. The study confirms the difficulty to remove Ca(OH)2 from root canals using conventional methods. The GentleWave system removed the paste within 90 seconds using water irrigation alone. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights

  1. 40 CFR 721.10018 - Calcium hydroxide oxide silicate (Ca6(OH)2O2(Si2O5)3).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Calcium hydroxide oxide silicate (Ca6... New Uses for Specific Chemical Substances § 721.10018 Calcium hydroxide oxide silicate (Ca6(OH)2O2... substance identified as calcium hydroxide oxide silicate (Ca6(OH)2O2(Si2O5)3) (PMN P-01-442; CAS No....

  2. 40 CFR 721.10018 - Calcium hydroxide oxide silicate (Ca6(OH)2O2(Si2O5)3).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Calcium hydroxide oxide silicate (Ca6... New Uses for Specific Chemical Substances § 721.10018 Calcium hydroxide oxide silicate (Ca6(OH)2O2... substance identified as calcium hydroxide oxide silicate (Ca6(OH)2O2(Si2O5)3) (PMN P-01-442; CAS No....

  3. 40 CFR 721.10018 - Calcium hydroxide oxide silicate (Ca6(OH)2O2(Si2O5)3).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Calcium hydroxide oxide silicate (Ca6... New Uses for Specific Chemical Substances § 721.10018 Calcium hydroxide oxide silicate (Ca6(OH)2O2... substance identified as calcium hydroxide oxide silicate (Ca6(OH)2O2(Si2O5)3) (PMN P-01-442; CAS No....

  4. 40 CFR 721.10018 - Calcium hydroxide oxide silicate (Ca6(OH)2O2(Si2O5)3).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Calcium hydroxide oxide silicate (Ca6... New Uses for Specific Chemical Substances § 721.10018 Calcium hydroxide oxide silicate (Ca6(OH)2O2... substance identified as calcium hydroxide oxide silicate (Ca6(OH)2O2(Si2O5)3) (PMN P-01-442; CAS No....

  5. 40 CFR 721.10018 - Calcium hydroxide oxide silicate (Ca6(OH)2O2(Si2O5)3).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Calcium hydroxide oxide silicate (Ca6... New Uses for Specific Chemical Substances § 721.10018 Calcium hydroxide oxide silicate (Ca6(OH)2O2... substance identified as calcium hydroxide oxide silicate (Ca6(OH)2O2(Si2O5)3) (PMN P-01-442; CAS No....

  6. Simvastatin versus Calcium Hydroxide Direct Pulp Capping of Human Primary Molars: A Randomized Clinical Trial

    PubMed Central

    Asl Aminabadi, Naser; Maljaei, Ensiyeh; Erfanparast, Leila; Ala Aghbali, Amir; Hamishehkar, Hamed; Najafpour, Ebrahim

    2013-01-01

    Background and aims The aim of present study was to investigate pulp-dentin complex reactions following direct pulp capping (DPC) with calcium hydroxide [Ca(OH)2] and simvastatin as pulp-capping materials in the primary human molars. Materials and methods 120 primary molar teeth which had to be extracted for orthodontic reasons were randomly allocated into four groups. Group Ι as a control, underwent DPC with calcium hydroxide. The dental pulp in group ІІ, ІІІ and ІV were directly capped with simvastatin-based materials at concentrations of 1, 5 and 10 µM, respectively. All of the teeth were restored with stainless steel crown. After a mean period of 7.41 months teeth were extracted and processed for histological examination and categorized in terms of hard tissue formation and pulp inflammation. Results Teeth in group I had statistically favorable outcomes in hard tissue formation and pulp inflammation than did the groups ІІ, ІІІ and ІV (P < 0.001). Considering three different concentrations of simvastatin, the result showed a dose dependent trend. Teeth in group ІV showed significantly lower rates of hard tissue formation and higher rates of pulp inflammation and necrosis compared to those of groups ІІ (P < 0.05). Conclusion The findings of this study depicted that healing with no inflammation and hard tissue formation following statin treatment occurs with a lower rate than that with the calcium hydroxide. PMID:23487477

  7. Effects of calcium hydroxide addition on the physical and chemical properties of a calcium silicate-based sealer

    PubMed Central

    KUGA, Milton Carlos; DUARTE, Marco Antonio Hungaro; SANT'ANNA-JÚNIOR, Arnaldo; KEINE, Kátia Cristina; FARIA, Gisele; DANTAS, Andrea Abi Rached; GUIOTTI, Flávia Angélica

    2014-01-01

    Recently, various calcium silicate-based sealers have been introduced for use in root canal filling. The MTA Fillapex is one of these sealers, but some of its physicochemical properties are not in accordance with the ISO requirements. Objective The aim of this study was to evaluate the flowability, pH level and calcium release of pure MTA Fillapex (MTAF) or containing 5% (MTAF5) or 10% (MTAF10) calcium hydroxide (CH), in weight, in comparison with AH Plus sealer. Material and Methods The flowability test was performed according to the ISO 6876:2001 requirements. For the pH level and calcium ion release analyses, the sealers were placed individually (n=10) in plastic tubes and immersed in deionized water. After 24 hours, 7 and 14 days, the water in which each specimen had been immersed was evaluated to determine the pH level changes and calcium released. Flowability, pH level and calcium release data were analyzed statistically by the ANOVA test (α=5%). Results In relation to flowability: MTAF>AH Plus>MTAF5>MTAF10. In relation to the pH level, for 24 h: MTAF5=MTAF10=MTAF>AH Plus; for 7 and 14 days: MTAF5=MTAF10>MTAF>AH Plus. For the calcium release, for all periods: MTAF>MTAF5=MTAF10>AH Plus. Conclusions The addition of 5% CH to the MTA Fillapex (in weight) is an alternative to reduce the high flowability presented by the sealer, without interfering in its alkalization potential. PMID:25025558

  8. [Study of some physical and biological properties of an endodontic sealer composed of calcium hydroxide].

    PubMed

    Birman, E G; Sampaio, J M; Magalhães, J; Sato, E

    1990-01-01

    The authors present a study of the physical and biological properties of a new endodontic cement known as Sealapex. In its composition the presence of calcium hydroxide is introduced in order to induce calcification of the periapical tissue. Our results using glass round cover slips implanted on the subcutaneous tissue of mice indicated a persistent foreign body reaction (60 days). The physical properties studied compared to N-Rickert ciment indicated, a decreased leakage. Adhesivity tests didn't give us significant values. Laboratorial studies and clinical trials are necessary to a complete acceptance of this new ciment in endodontic treatment.

  9. [The effect of a combined nanoparticulate/calcium hydroxide medication on the biofilm of Enterococcus faecalis in starvation phase].

    PubMed

    Zhang, Fu-hua; Li, Mao; Wei, Zhi-jun; Zhao, Bing

    2016-02-01

    To evaluate the efficacy of Ca(OH)2 with a silver nanoparticle suspension to eliminate the biofilm of Enterococcus faecalis (E. faecalis) in starvation phase. The biofilm models of E.faecalis in the starvation phase were built in vitro with 256 extracted human single-rooted teeth, and the methods of plate culture count and crystal violet biofilm assay were applied to determine the effect of the inhibition of different intracanal medicament (silver nanoparticle with calcium hydroxide, silver nanoparticle alone, calcium hydroxide alone ) to the biofilm of E. faecalis in starvation phase at 1 and 7 days. The negative control group was treated with sterile water only. Statistical analysis was carried out with SPSS 13.0 software package. The inhibitory effect of Ca(OH)2+nanosilver on the biofilms of E. faecalis was found more significant than that of silver nanoparticle alone and calcium hydroxide alone at 1 and 7 days, and silver nanoparticle alone was more effective than calcium hydroxide alone. No difference in antimicrobial properties was observed between the two time points in the Ca(OH)2+silver nanoparticle group and silver nanoparticle group, while higher antimicrobial efficacy was observed in the Ca(OH)2 group after 7 days than 1 day. Silver nanoparticle with calcium hydroxide has an obvious inhibitory effect on the biofilm of E.faecalis in the starvation phase.

  10. Improving the quality of rice straw by urea and calcium hydroxide on rumen ecology, microbial protein synthesis in beef cattle.

    PubMed

    Polyorach, S; Wanapat, M

    2015-06-01

    Four rumen-fistulated beef cattle were randomly assigned to four treatments according to a 4 × 4 Latin square design to study the influence of urea and calcium hydroxide [Ca(OH)2 ] treatment of rice straw to improve the nutritive value of rice straw. Four dietary treatments were as follows: untreated rice straw, 50 g/kg urea-treated rice straw, 20 g/kg urea + 20 g/kg calcium hydroxide-treated rice straw and 30 g/kg urea + 20 g/kg calcium hydroxide-treated rice straw. All animals were kept in individual pens and fed with concentrate at 0.5 g/kg of BW (DM), rice straw was fed ad libitum. The experiment was conducted for four periods, and each period lasted for 21 days. During the first 14 days, DM feed intake measurements were made while during the last 7 days, all cattle were moved to metabolism crates for total faeces and urine collections. The results revealed that 20 g/kg urea + 20 g/kg calcium hydroxide-treated rice straw improved the nutritive value of rice straw, in terms of dry matter intake, digestibility, ruminal volatile fatty acids, population of bacteria and fungi, nitrogen retention and microbial protein synthesis. Based on this study, it could be concluded that using urea plus calcium hydroxide was one alternative method to improve the nutritive value of rice straw, rumen ecology and fermentation and thus a reduction of treatment cost.

  11. Periapical tissue reactions to calcium hydroxide and MTA after external root resorption as a sequela of delayed tooth replantation.

    PubMed

    Marão, Heloisa Fonseca; Panzarini, Sônia Regina; Aranega, Alessandra Marcondes; Sonoda, Celso Koogi; Poi, Wilson Roberto; Esteves, Jônatas Caldeiras; Silva, Pedro Ivo Santos

    2012-08-01

    Clinical experience has shown that most avulsed teeth are replanted after a long extra-alveolar time and dry or inadequate wet storage, causing necrosis of periodontal ligament cells. This condition invariably leads to development of external root resorption, leaving the filling material in contact with the periapical connective tissues. In this study, the periapical tissue reactions to calcium hydroxide (CH) and mineral trioxide aggregate (MTA) were evaluated after occurrence of external root resorption as an expected sequela of delayed tooth replantation. Twenty male Wistar rats (Rattus norvegicus, albinus) had their right upper incisor extracted and maintained in dry storage for 60 min. Then, the dental papilla, enamel organ, pulp tissue, and periodontal ligament were removed, and the teeth were immersed in a 2% acidulated phosphate sodium fluoride solution, pH 5.5, for 10 min. The teeth were randomly assigned into two groups (n = 10), in which the canals were filled with either a CH and saline paste (CH group) or MTA (MTA group). The sockets were irrigated with saline, and the teeth were replanted. After 80 days, it was possible to observe large areas of replacement root resorption and some areas of inflammatory root resorption in both groups. More severe inflammatory tissue reaction was observed in contact with calcium hydroxide compared with the mineral trioxide aggregate. New bone formation was more intense at the bottom of the socket in the MTA group. In conclusion, as far as periapical tissue compatibility is concerned, intracanal MTA can be considered as a viable option for root canal filling in delayed tooth replantation, in which external root resorption is an expected sequela.

  12. Comparison of Antifungal Activity of 2% Chlorhexidine, Calcium Hydroxide, and Nanosilver gels against Candida Albicans

    PubMed Central

    Mozayeni, Mohammad Ali; Hadian, Ali; Bakhshaei, Pedram; Dianat, Omid

    2015-01-01

    Objectives: Residual microorganisms in the root canal system (RCS) after endodontic therapy such as Candida albicans are a major cause of endodontic failure. Calcium hydroxide (CH) and chlorhexidine (CHX) have suitable antimicrobial activity against bacteria and can be used as intracanal medicaments. Nanosilver has also shown antimicrobial activity against microorganisms. This study aimed to compare the antifungal effect of calcium hydroxide, 2% chlorhexidine and nanosilver gels on Candida albicans. Materials and Methods: Eighty-one single-rooted teeth were selected. After root canal preparation, the teeth were contaminated. After culture, the teeth were randomly divided into 4 groups. In experimental groups, 24 teeth were selected and completely filled with CH, 2% CHX and nanosilver gels in each group. Nine teeth were selected in the control group and filled with saline solution. After 1, 3, and 7 days, samples were obtained by #30 sterile paper points, and #2 and #4 Gates Glidden drills and cultured on solid Sabouraud agar. Results: The results demonstrated that CH and 2% CHX had equal antifungal effects on samples taken by paper point and #2 Gates Glidden drill at all time points. Both CH and 2% CHX were more effective than nanosilver at all time periods. There was no statistically significant difference between medicaments in samples taken by #4 Gates Glidden drill. Conclusion: CH and 2% CHX gels have significantly higher antifungal activity than nanosilver gel. Also, CH and 2% CHX gels are equally effective against Candida albicans. PMID:26056520

  13. Light-cured calcium hydroxide vs formocresol in human primary molar pulpotomies: a randomized controlled trial.

    PubMed

    Zurn, Derek; Seale, N Sue

    2008-01-01

    The purpose of this prospective study was to compare light-cured calcium hydroxide (Ca(OH)2) with diluted formocresol (FC) for its success as a primary molar pulpotomy medicament Selection criteria included at least 2 matching, asymptomatic, contralateral primary molars requiring vital pulpotomies. Matched teeth in each patient were randomized to receive either Ca(OH)2 or FC as a pulpotomy medicament. All teeth were restored with prefabricated metal crowns. Twenty patients (34 pairs of teeth) were followed clinically and radiographically for > or =1 year. Two blinded, standardized, and calibrated examiners evaluated and scored each radiograph for signs of pathology, based upon a modified scale previously proposed. Findings were grouped in: (a) 0 - 6; (b) 7 - 12; and (c) 13 - 24 month intervals. Radiographic scoring favored the FC group of the 7- to 12- and 13- to 24-month intervals (P<.05). Clinical success was similar for Ca(OH)2 (94%) and FC (97%) at 12 months or less. Beyond 12 months, clinical success varied more (Ca(OH)2=84%, FC=97%), but not significantly (P=.08). Combined success rates were lower for Ca(OH)2 (56%) than FC (94%). Light-cured calcium hydroxide does not appear to be a viable alternative to diluted formocresol as a pulpotomy agent.

  14. Evidence of pulpotomy in primary teeth comparing MTA, calcium hydroxide, ferric sulphate, and electrosurgery with formocresol.

    PubMed

    Stringhini Junior, E; Vitcel, M E B; Oliveira, L B

    2015-08-01

    The aim of this study was to evaluate the scientific evidence of pulpotomy in primary teeth comparing mineral troxide aggregate (MTA), calcium hydroxide, ferric sulphate, and electrosurgery with formocresol. A systematic search using key words was conducted using seven databases up to December 10, 2013. Clinical articles in English, Portuguese and Spanish were selected, which were in accordance with the inclusion and exclusion criteria and the research objective of comparing whether pulpotomy performed with formocresol in primary teeth is more effective than other medicaments or techniques. Out of the 12,515 publication initially identified, 30 clinical articles were included in the systematic review and analysed by four meta-analyses. The success rate of MTA (94.6 %) was higher than that of formocresol (87.4 %), with a statistically significant difference (OR = 0.39; 95 % CI = 0.25-0.62). Formocresol pulpotomy success was not statistically different from ferric sulphate or electrosurgery. MTA was clinically and radiographically superior to formocresol for pulpotomy of primary teeth. The other alternatives to formocresol such as electrosurgery and ferric sulphate can be used instead of formocresol since they showed success similar to formocresol. In addition, there is no evidence to support calcium hydroxide for pulpotomies in primary teeth.

  15. Formocresol versus calcium hydroxide direct pulp capping of human primary molars: two year follow-up.

    PubMed

    Aminabadi, Naser Asl; Farahani, Ramin Mostofi Zadeh; Oskouei, Sina Ghertasi

    2010-01-01

    Clinical and radiographic evaluation of the premedicated direct pulp capping using formocresol (PDC) versus conventional direct pulp capping using calcium hydroxide (CDC) in human carious primary molars. A total of 120 vital primary molars with pinpoint exposure during caries removal in 84 patients aged 4-5 years were selected. In the PDC group (n = 60), 20% Buckley's formocresol solution, and in the CDC group (n = 60), calcium hydroxide powder were applied to the exposure sites followed by placement of zinc oxide-eugenol base. Teeth were restored with preformed stainless steel crowns. Clinical and radiographic evaluations of the treatment outcomes were performed at regular intervals of 6 and 12 months, respectively, for two years post-operatively. The prevalence of spontaneous pain, sensitivity on percussion, and fistula were significantly higher in the CDC group compared to the PDC group (P < 0.05). The number of teeth exhibiting periapical/furcal radiolucency or external/internal root resorption was also higher in the CDC group (P < 0.05). The clinical success rate of the PDC was 90% compared to the 61.7% of the CDC (P < 0.05). The radiographic success rates of the PDC and CDC groups were 85% and 53.3%, respectively (P < 0.05). It seems formocresol premedicated direct pulp capping could safely be used as a substitute for conventional direct pulp capping.

  16. Influence of dentin on pH of 2% chlorhexidine gel and calcium hydroxide alone or in combination.

    PubMed

    Freire, Laila Gonzales; Carvalho, Ceci Nunes; Ferrari, Patricia Helena Pereira; Siqueira, Evandro Luiz; Gavini, Giulio

    2010-06-01

    The aims of endodontic treatment in cases of apical periodontitis are to reduce as much as possible the number of microorganisms inside the root canal system and to inactivate toxins produced by them. Most of the times, these objectives are not achieved solely by chemomechanical preparation, and intracanal dressing may be necessary. In these cases, calcium hydroxide is used as a root canal dressing due to its well-known and recognized antimicrobial activity. Chlorhexidine has a wide spectrum of antimicrobial activity and its association with calcium hydroxide has been recommended in an attempt to amplify antimicrobial effects of calcium hydroxide. It is also known that dentin exerts a buffering effect under wide pH variations, and may be responsible for decreasing the antimicrobial activity of drugs inside the root canal. The objectives of this study were to assess the pH of 2% chlorhexidine gel and calcium hydroxide alone or in combination, as well as the influence of dentin on the pH of these compounds. Dentin powder was obtained from bovine teeth and added as 1.8% to the volume of the medications. All substances were individually stored in plastic flasks, in triplicate. A pH meter was used at five different moments to assess pH in viscous medium: immediately after preparation and after 24 h, and 7, 14, and 21 days. Results were analyzed by paired Student's t-test. Statistically significant differences were observed in the 2% chlorhexidine gel group alone or associated with calcium hydroxide and added of dentin powder (P < 0.05). Mean pH values indicated the influence of dentin powder because of a significant increase in pH. Calcium hydroxide with propylene glycol as the vehicle always showed high pH, demonstrating that this compound was not affected by the presence of dentin.

  17. Carbonation as a binding mechanism for coal/calcium hydroxide pellets. Technical report, December 1, 1992--February 28, 1993

    SciTech Connect

    Rapp, D.; Lytle, J.; Hackley, K.; Dagamac, M.; Berger, R.; Schanche, G.

    1993-05-01

    Pelletization of fine coal with calcium hydroxide, a sulfur capturing sorbent, represents a method to produce a fuel which will burn in compliance with the recently passed Clean Air Act Amendments (CAAA`s). To harden the pellets, the reaction of carbon dioxide with calcium hydroxide, referred to as carbonation, is being studied. Carbonation forms a bonding matrix of calcium carbonate. This is a two-year research program. This report covers the second quarter of the second year. Research is indicating that 5 to 10 wt% calcium hydroxide pellets can be produced via a roller-and-die pellet mill and air cured to achieve sufficient quality for handling and transportation. This quarter, 1/2 inch-diameter pellets containing 10% calcium hydroxide were demonstrated to gradually react with atmospheric carbon dioxide (3 days) while air drying to achieve compressive strengths equivalent to those attained for fully dried pellets which had been carbonated for one-hour with 100% commercial grade carbon dioxide. It was also demonstrated that an organic, adhesive binder, corn starch, can be very effective at producing strong pellets but drying is required before appreciable pellet strength is attained. For pellets containing 2 wt% corn starch, it was determined that less than 50% of the ultimate strength was achieved as the pellets were dried from 20 wt% to 5 wt% moisture. Strength improved considerably as the pellet moisture content was reduced below 5 wt%.

  18. Critical review: Injectability of calcium phosphate pastes and cements.

    PubMed

    O'Neill, R; McCarthy, H O; Montufar, E B; Ginebra, M-P; Wilson, D I; Lennon, A; Dunne, N

    2017-03-01

    Calcium phosphate cements (CPC) have seen clinical success in many dental and orthopaedic applications in recent years. The properties of CPC essential for clinical success are reviewed in this article, which includes properties of the set cement (e.g. bioresorbability, biocompatibility, porosity and mechanical properties) and unset cement (e.g. setting time, cohesion, flow properties and ease of delivery to the surgical site). Emphasis is on the delivery of calcium phosphate (CaP) pastes and CPC, in particular the occurrence of separation of the liquid and solid components of the pastes and cements during injection; and established methods to reduce this phase separation. In addition a review of phase separation mechanisms observed during the extrusion of other biphasic paste systems and the theoretical models used to describe these mechanisms are discussed.

  19. Booster vaccination against diphtheria and tetanus in man. Comparison of calcium phosphate and aluminium hydroxide as adjuvants--II.

    PubMed

    Aggerbeck, H; Fenger, C; Heron, I

    1995-10-01

    Diphtheria and tetanus antibody levels were measured before and four weeks after booster vaccination of 313 Danish military recruits participating in a clinical trial to compare aluminium hydroxide and calcium phosphate as adjuvants in diphtheria-tetanus vaccines (DT). Twenty-eight percent of the men had a diphtheria pre-vaccination content below a protective level of 0.01 IU ml-1. The calcium phosphate adsorbed vaccine showed the highest efficacy for both antigens. Adverse reactions were rare but more frequent in the calcium group than in the aluminium group. No correlation was found between pre- or post-vaccination levels and adverse reactions and both vaccines gave rise to specific IgE formation. The results show that calcium phosphate is more effective but not a safer alternative to aluminium hydroxide when compared in vaccines containing 1.0 mg ml-1 of Ca or of Al.

  20. [Growth and metabolism of calcium in rats chronically poisoned with aluminium hydroxide].

    PubMed

    Mahieu, S; Calvo, M L; Millen, N; Gonzalez, M; Contini, M C

    1998-01-01

    The effects of aluminum on growth have been studied in rats chronically poisoned with aluminum hydroxide (80 mg/kg b.w.-i.p.-three times a week, during 6 months) and in control rats, between 3 and 26 weeks of age. The growth data was evaluated according to Parks 'theory of feeding an growth. At the end of the poisoning period, the calcium metabolism was studied through a balance of calcium and the determination of bone Ca++ accretion and resorption rates with the aid of 45Ca++. The parathyroid glands function was studied using an indirect method. Treated rats showed a significant decrease in asymptotic weights and in the initial efficiency of food conversion into biomass regarding controls. No differences were observed in food intake between both group. Aluminum affected neither the peak growth rate nor the time necessary to attain maturity. The calcium balance in treated rats was significantly less than in the control group. This was accompanied by a significant increase in the calcium excreted by faces, caused perhaps by a less intestinal absorption. An important amount of aluminum on the surface of the trabecular bone and a reduction in the skeletal Ca++ mass, was observed in all treated rats. Nevertheless there are no differences in the latter when expressed for 100 g of body weight. The rate of skeletal Ca++ accretion was found to be significantly decreased in treated group with respect to controls, without any changes in the bone Ca resorption rate. The reduction in bone turnover revealed by the decrease of Vo+/Vo- was accompanied by less recovery velocity of calcemia in the aluminum treated group, being indirectly related to the parathyroid gland response to calcium depletion. In the model that we studied the decreased bone turnover could have been caused by deposits of aluminum in bone; however there could exist associated factors such as dysfunction in the secretion of PTH, or less affinity between its receptors at the bone level.

  1. Polymer Coated CaAl-Layered Double Hydroxide Nanomaterials for Potential Calcium Supplement

    PubMed Central

    Kim, Tae-Hyun; Lee, Jeong-A; Choi, Soo-Jin; Oh, Jae-Min

    2014-01-01

    We have successfully prepared layered double hydroxide (LDH) nanomaterials containing calcium and aluminum ions in the framework (CaAl-LDH). The surface of CaAl-LDH was coated with enteric polymer, Eudragit®L 100 in order to protect nanomaterials from fast dissolution under gastric condition of pH 1.2. The X-ray diffraction patterns, Fourier transform infrared spectroscopy, scanning electron and transmission electron microscopy revealed that the pristine LDH was well prepared having hydrocalumite structure, and that the polymer effectively coated the surface of LDH without disturbing structure. From thermal analysis, it was determined that only a small amount (less than 1%) of polymer was coated on the LDH surface. Metal dissolution from LDH nanomaterials was significantly reduced upon Eudragit®L 100 coating at pH 1.2, 6.8 and 7.4, which simulates gastric, enteric and plasma conditions, respectively, and the dissolution effect was the most suppressed at pH 1.2. The LDH nanomaterials did not exhibit any significant cytotoxicity up to 1000 μg/mL and intracellular calcium concentration significantly increased in LDH-treated human intestinal cells. Pharmacokinetic study demonstrated absorption efficiency of Eudragit®L 100 coated LDH following oral administration to rats. Moreover, the LDH nanomaterials did not cause acute toxic effect in vivo. All the results suggest the great potential of CaAl-LDH nanomaterials as a calcium supplement. PMID:25490138

  2. Polymer coated CaAl-layered double hydroxide nanomaterials for potential calcium supplement.

    PubMed

    Kim, Tae-Hyun; Lee, Jeong-A; Choi, Soo-Jin; Oh, Jae-Min

    2014-12-05

    We have successfully prepared layered double hydroxide (LDH) nanomaterials containing calcium and aluminum ions in the framework (CaAl-LDH). The surface of CaAl-LDH was coated with enteric polymer, Eudragit®L 100 in order to protect nanomaterials from fast dissolution under gastric condition of pH 1.2. The X-ray diffraction patterns, Fourier transform infrared spectroscopy, scanning electron and transmission electron microscopy revealed that the pristine LDH was well prepared having hydrocalumite structure, and that the polymer effectively coated the surface of LDH without disturbing structure. From thermal analysis, it was determined that only a small amount (less than 1%) of polymer was coated on the LDH surface. Metal dissolution from LDH nanomaterials was significantly reduced upon Eudragit®L 100 coating at pH 1.2, 6.8 and 7.4, which simulates gastric, enteric and plasma conditions, respectively, and the dissolution effect was the most suppressed at pH 1.2. The LDH nanomaterials did not exhibit any significant cytotoxicity up to 1000 μg/mL and intracellular calcium concentration significantly increased in LDH-treated human intestinal cells. Pharmacokinetic study demonstrated absorption efficiency of Eudragit®L 100 coated LDH following oral administration to rats. Moreover, the LDH nanomaterials did not cause acute toxic effect in vivo. All the results suggest the great potential of CaAl-LDH nanomaterials as a calcium supplement.

  3. Properties of high calcium fly ash geopolymer pastes with Portland cement as an additive

    NASA Astrophysics Data System (ADS)

    Phoo-ngernkham, Tanakorn; Chindaprasirt, Prinya; Sata, Vanchai; Pangdaeng, Saengsuree; Sinsiri, Theerawat

    2013-02-01

    The effect of Portland cement (OPC) addition on the properties of high calcium fly ash geopolymer pastes was investigated in the paper. OPC partially replaced fly ash (FA) at the dosages of 0, 5%, 10%, and 15% by mass of binder. Sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) solutions were used as the liquid portion in the mixture: NaOH 10 mol/L, Na2SiO3/NaOH with a mass ratio of 2.0, and alkaline liquid/binder (L/B) with a mass ratio of 0.6. The curing at 60°C for 24 h was used to accelerate the geopolymerization. The setting time of all fresh pastes, porosity, and compressive strength of the pastes at the stages of 1, 7, 28, and 90 d were tested. The elastic modulus and strain capacity of the pastes at the stage of 7 d were determined. It is revealed that the use of OPC as an additive to replace part of FA results in the decreases in the setting time, porosity, and strain capacity of the paste specimens, while the compressive strength and elastic modulus seem to increase.

  4. Histological response of human pulps capped with calcium hydroxide and a self-etch adhesive containing an antibacterial component

    PubMed Central

    Parthasarathy, Ambalavanan; Kamat, Sharad B.; Kamat, Mamta; Kidiyoor, Krishnamurthy Haridas

    2016-01-01

    Aim: To compare human pulp tissue response following direct pulp capping with calcium hydroxide and a self-etch adhesive containing antibacterial component. Materials and Methods: Sixty-six erupted sound premolars scheduled to be extracted for orthodontic reasons were selected from 17 human subjects. Pulp exposures were made. Direct pulp capping was then performed using calcium hydroxide and a self-etch adhesive containing antibacterial component in its primer. The teeth were then restored with composite resin. Two teeth were maintained intact as a control group. After 7 and 30 days, teeth were extracted and processed for light microscopic examination using a histological scoring system. The teeth were divided into four groups (N = 16) according to the pulp capping materials used and their days of extraction. The results were then statistically analyzed by Mann-Whitney U-test. Results: After the 7-day observation period, the inflammatory reaction to the self-etch adhesive containing antibacterial component group was significantly less severe than that in the calcium hydroxide group (P < 0.05). After the 30-day observation period, the inflammatory reaction was slight in both groups, but specimens with dentin bridge formation in the self-etch adhesive group were significantly less common than those in the calcium hydroxide group (P < 0.05). PMID:27217644

  5. In vitro susceptibility of oral Candida albicans strains to different pH levels and calcium hydroxide saturated aqueous solution.

    PubMed

    Weckwerth, Paulo Henrique; Carnietto, Cristiane; Weckwerth, Ana Carolina Villas Boas; Duarte, Marco Antonio Hungaro; Kuga, Milton Carlos; Vivan, Rodrigo Ricci

    2012-01-01

    Candida albicans is present in the oral cavity and in the whole digestive tract of humans and other animals, being frequently related to endodontic treatment failure. The present study determined the incidence of C. albicans in the oral cavity and the susceptibility of isolates to different pH values and saturated calcium hydroxide aqueous solution at pH 12.5. Sixty-five patients attending the Endodontic Clinic at the Sagrado Coração University participated in the study. The collected samples were cultivated in selective media for C. albicans and the isolates were tested in terms of resistance to both alkaline pH and saturated aqueous solution of calcium hydroxide. In relation to time variables, yeast viability was assessed by the Sabouraud's agar culture and fluorescein diacetate and ethidium bromide fluorescent staining method. Results from the different pHs and experimental times, including those from different techniques measuring fungal viability, were compared using the chi-square and Fisher's exact tests (α=0.05). The yeasts became completely inviable after 48 h of contact with the calcium hydroxide solution. On the other hand, when exposed to the alkaline culture broth, the yeasts were found to be viable at pHs 9.5 and 10.5 for up to 7 days. In conclusion, C. albicans can only be completely inhibited by direct contact with saturated calcium hydroxide aqueous solution after 48 h of exposure.

  6. Effect on the healing of periapical perforations in dogs of the addition of growth factors to calcium hydroxide.

    PubMed

    Kim, M; Kim, B; Yoon, S

    2001-12-01

    The purpose of this study was to investigate the effect of the addition of platelet-derived growth factor-BB and insulin-like growth factor-I to calcium hydroxide in the repair of apical perforations in dogs. Fifty-one premolar teeth of four beagle dogs were used. After developing periapical lesions root apices were artificially perforated. The teeth were divided into the three groups: group 1, the apical perforations were not sealed; group 2, the perforated areas were obturated with calcium hydroxide; and group 3, calcium hydroxide plus growth factors was applied to the sites of perforation. All canals were filled by a lateral condensation technique. Animals were killed 12 wk later, and sections were hematoxylin & eosin-stained and immunostained for osteonectin. The amount of inflammation was evaluated histomorphologically. The one-way ANOVA test demonstrated that the three groups were significantly different from one another. In group 3 there was no inflammatory reaction of apical tissue, and the connective tissue adjacent to the newly formed hard tissue was strongly immunostained for osteonectin. Most sections in group 1 showed no apical healing. Moderate healing was found in group 2. In conclusion the combination of platelet-derived growth factor-BB and insulin-like growth factor-I with calcium hydroxide improved healing of apical perforation in dogs.

  7. Effect of calcium hydroxide application to feedlot pen surface material on ammonia, odor, and greenhouse gas emissions

    USDA-ARS?s Scientific Manuscript database

    Calcium hydroxide (lime) is used to reduce microorganisms and odors in human biosolids, animal and poultry manures, and abattoir wastes. In the cattle industry, lime has been used as a disinfectant and is spread on the pen surface to control infections such as diarrhea and foot rot. The increase in ...

  8. Histological comparison of alendronate, calcium hydroxide and formocresol in amputated rat molar.

    PubMed

    Cengiz, S Burcak; Batirbaygil, Yildiz; Onur, Mehmet Ali; Atilla, Pergin; Asan, Esin; Altay, Nil; Cehreli, Zafer C

    2005-10-01

    The purpose of this study was to evaluate the potential of alendronate sodium (ALN), a biphosohonate to stimulate hard tissue formation in pulpotomized (amputated) rat molars. Two commonly used pulpotomy materials, calcium hydroxide (CH) and formocresol (FC) were utilized for comparisons. Histological evaluations were performed by observers blinded to treatment allocation on days 7, 15, 30 and 60, followed by statistical analysis of selected histological criteria. In all evaluation periods, hard tissue deposition was evident along the radicular dentin in ALN and CH groups. In days 30 and 60, the latter two groups showed no differences in inflammatory cell response and hard tissue deposition scores (P > 0.05). ALN appears to be capable of maintaining pulpal vitality, while promoting hard tissue formation, similar to CH.

  9. A Comparative Analysis of Antimicrobial Property of Wine and Ozone with Calcium Hydroxide and Chlorhexidine

    PubMed Central

    Ebenezar, A. V. Rajesh; Anand, Nirupa; Mary, A.Vinita; Mony, Bejoy

    2015-01-01

    Background The antibacterial properties of wine and ozone have been established but their antibacterial efficacies against endodontic pathogens are yet to be ascertained. Aim The purpose of this study is to comparatively evaluate the antibacterial property of ozonated water, white wine (14%) and de-alcoholised white wine. Materials and Methods S.mutans and E.faecalis were subcultured and inoculated in a nutrient broth for 24 hours. The following groups were formulated: Group 1A:2% Chlorhexidine (Control group); Group 1B:White wine; Group 1C:Dealcoholised white wine; Group 1D:Ozonated water; Group 2A: Ca(OH)2 + Chlorhexidine (Control group); Group 2B: White wine + Ca(OH)2; Group 2C:De-alcoholised White wine + Ca(OH)2 + chlorhexidine; Group 2D:White wine + Ca(OH)2 + chlorhexidine and group 2E: Dealcoholised white wine + Ca(OH)2 + chlorhexidine. The samples were allowed to diffuse into the culture medium for two hours, later the S. mutans were streaked on to the blood agar medium and the E. faecalis were streaked on to the Muller Hilton agar medium and incubated for 48 hours at 370C the zone of inhibition was measured after 48 hours. Results There was no growth of microorganisms seen with ozonated water. Chlorhexidine showed large zone of inhibition compared to the other groups. White wine has better antimicrobial property than de-alcoholised white wine, but when mixed with calcium hydroxide the dealcoholised white wine has better action against the microorganisms. Conclusion Ozonated water has the best antibacterial property and the antibacterial action of Calcium hydroxide is enhanced when it is mixed with de-alcoholised white wine. PMID:26266206

  10. Porosity-strength relation in calcium aluminate cement pastes

    SciTech Connect

    Matusinovic, T.; Sipusic, J.; Vrbos, N

    2003-11-01

    The compressive strength and the volume porosity of calcium aluminate cement pastes have been studied in order to connect their relationship. The influence of mass fraction of lithium carbonate on compressive strength and porosity of calcium aluminate cement (CAC) has been investigated at different water-cement (w/c) ratios. The functions proposed in the literature for different technical materials were tested on obtained strength and porosity data. Those functions have been a base for further development of more general functional dependence of strength and porosity for cement materials. Thus, we propose the following equation to relate the strength and porosity for CAC pastes:{sigma}={sigma}{sub P0}1-PP{sub 0}{sup 2}.

  11. A preliminary report on histological outcome of pulpotomy with endodontic biomaterials vs calcium hydroxide

    PubMed Central

    Peimani, Ali; Asgary, Saeed

    2013-01-01

    Objectives The purpose of the study was to evaluate human dental pulp response to pulpotomy with calcium hydroxide (CH), mineral trioxide aggregate (MTA), and calcium enriched mixture (CEM) cement. Materials and Methods A total of nine erupted third molars were randomly assigned to each pulpotomy group. The same clinician performed full pulpotomies and coronal restorations. The patients were followed clinically for six months; the teeth were then extracted and prepared for histological assessments. The samples were blindly assessed by an independent observer for pulp vitality, pulp inflammation, and calcified bridge formation. Results All patients were free of clinical signs/symptoms of pulpal/periradicular diseases during the follow up period. In CH group, one tooth had necrotic radicular pulp; other two teeth in this group had vital uninflamed pulps with complete dentinal bridge formation. In CEM cement and MTA groups all teeth had vital uninflamed radicular pulps. A complete dentinal bridge was formed beneath CEM cement and MTA in all roots. Odontoblast-like cells were present beneath CEM cement and MTA in all samples. Conclusions This study revealed that CEM cement and MTA were reliable endodontic biomaterials in full pulpotomy treatment. In contrast, the human dental pulp response to CH might be unpredictable. PMID:24303358

  12. Reduction in dentin permeability using a slurry containing dicalcium phosphate and calcium hydroxide.

    PubMed

    Cherng, Aishuan Maria; Takagi, Shozo; Chow, Laurence

    2006-08-01

    Treatments that obdurate dentin tubules have been used for reducing dentin hypersensitivity. The purpose of this study was to determine the effect of a treatment with a slurry of micron sized calcium phosphate on the hydraulic conductance (L(p)) of etched dentin discs in vitro. The treatment slurry was prepared by mixing a powder mixture of dicalcium phosphate anhydrous and calcium hydroxide with a solution that contained sodium fluoride and carboxymethyl cellulose. The mean baseline L(p) (in mL cm(-2) s(-1) H(2)O cm(-1)) was 2.07 +/- 1.45 (mean +/- SD; n = 13)). After one treatment and 2, 4, and 7 days of incubation in a protein-free saliva-like solution (SLS), the mean relative L(p), presented as % of baseline, were 65 +/- 16, 42 +/- 27, 36 +/- 26, and 33 +/- 27 (n = 13), respectively. The L(p) values of the baseline and treatment after incubation in the SLS were significantly (p < 0.05) different. Scanning electron microscopic examination showed partial obturation of dentin tubules in the treated dentin. X-ray diffraction and chemical analyses indicated the major product formed from the slurry was a fluoride-containing hydroxyapatite. Treatment appeared effective in further reducing L(p) of dentin discs after incubation in the SLS.

  13. Kinetics and Mechanism of Calcium Hydroxide Conversion into Calcium Alkoxides: Implications in Heritage Conservation Using Nanolimes.

    PubMed

    Rodriguez-Navarro, Carlos; Vettori, Irene; Ruiz-Agudo, Encarnacion

    2016-05-24

    Nanolimes are alcohol dispersions of Ca(OH)2 nanoparticles used in the conservation of cultural heritage. Although it was believed that Ca(OH)2 particles were inert when dispersed in short-chain alcohols, it has been recently shown that they can undergo transformation into calcium alkoxides. Little is known, however, about the mechanism and kinetics of such a phase transformation as well as its effect on the performance of nanolimes. Here we show that Ca(OH)2 particles formed after lime slaking react with ethanol and isopropanol and partially transform (fractional conversion, α up to 0.08) into calcium ethoxide and isopropoxide, respectively. The transformation shows Arrhenius behavior, with apparent activation energy Ea of 29 ± 4 and 37 ± 6 kJ mol(-1) for Ca-ethoxide and Ca-isopropoxide conversion, respectively. High resolution transmission electron microscopy analyses of reactant and product phases show that the alkoxides replace the crystalline structure of Ca(OH)2 along specific [hkl] directions, preserving the external hexagonal (platelike) morphology of the parent phase. Textural and kinetic results reveal that this pseudomorphic replacement involves a 3D diffusion-controlled deceleratory advancement of the reaction front. The results are consistent with an interface-coupled dissolution-precipitation replacement mechanism. Analysis of the carbonation of Ca(OH)2 particles with different degree of conversion into Ca-ethoxide (α up to 0.08) and Ca-isopropoxide (α up to 0.04) exposed to air (20 °C, 80% relative humidity) reveals that Ca-alkoxides significantly reduce the rate of transformation into cementing CaCO3 and induce the formation of metastable vaterite, as opposed to stable calcite which forms in untransformed Ca(OH)2 samples. Similar effects are obtained when a commercial nanolime partially transformed into Ca-ethoxide is subjected to carbonation. Such effects may hamper/delay the strengthening or consolidation effects of nanolimes, thus having

  14. Synthesis, spectroscopic and electrochemical performance of pasted β-nickel hydroxide electrode in alkaline electrolyte.

    PubMed

    Shruthi, B; Bheema Raju, V; Madhu, B J

    2015-01-25

    β-Nickel hydroxide (β-Ni(OH)2) was successfully synthesized using precipitation method. The structure and property of the β-Ni(OH)2 were characterized by X-ray diffraction (XRD), Fourier Transform infra-red (FT-IR), Raman spectra and thermal gravimetric-differential thermal analysis (TG-DTA). The results of the FTIR spectroscopy and TG-DTA studies indicate that the β-Ni(OH)2 contains water molecules and anions. The microstructural and composition studies have been performed using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) analysis. A pasted-type electrode is prepared using β-Ni(OH)2 powder as the active material on a nickel sheet as a current collector. Cyclic voltammetry (CV) and Electrochemical impedance spectroscopy (EIS) studies were performed to evaluate the electrochemical performance of the β-Ni(OH)2 electrode in 6M KOH electrolyte. CV curves showed a pair of strong redox peaks as a result of the Faradaic redox reactions of β-Ni(OH)2. The proton diffusion coefficient (D) for the present β-Ni(OH)2 electrode material is found to be 1.44×10(-12) cm(2) s(-1). Further, electrochemical impedance studies confirmed that the β-Ni(OH)2 electrode reaction processes are diffusion controlled. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Aqueous and surface chemistry of calcium-metal hydroxides in high pH environments

    SciTech Connect

    Cocke, D.L.; Mollah, M.Y.A.; Hess, T.R.; Lin, T.C.

    1997-08-01

    There is considerable interest in the chemistry associated with hazardous waste treatment by cement. The hydration of Portland cement is retarded in presence of zinc, cadmium and lead ions. Mixed hydroxides of calcium, zinc, cadmium and lead have been recently identified in the high pH environments of hydrating cement. FTIR, XRD, SEM, and SPM have been used to characterize these systems. A chemical equilibrium model of the early hydration of a zinc-doped cement/water system, Na-K-Ca-ZnH-SO{sub 4}-OH-Zn(OH){sub 2}-Zn(OH){sub 3}-Zn(OH){sub 4}-H{sub 2}O, has been developed to better understand the mechanism of the surface formation of calcium hydroxyzincate (CHZ). The model is based on Pitzer`s semi-empirical method for calculation of ion-activity coefficients at high ionic strength. The Pitzer parameters for Na{sup +}-Zn{sup 2+}, Na{sup +}-Zn{sup 2+}-SO{sub 4}{sup 2{minus}} and K{sup +}-Zn(OH){sub 4}{sup 2{minus}} have been evaluated, and the results successfully predict the equilibria (solubilities) of Na{sub 2}SO{sub 4}-ZnSO{sub 4}-H{sub 2}O, NaOH-Zn(OH){sub 2}-H{sub 2}O and KOH-ZnO-H{sub 2}O systems. The chemical model clearly demonstrates that the formation of CHZ on the calcium-silica-hydrate (C-S-H) surface is critically controlled by the Ca{sup 2+} ion concentration as well as pH of the pore water system. The results of this study suggest that the growth of CHZ is preceded by surface complex formation. Sequential charge control and sequential structure development have been used to discuss the surface selectivity of these compounds and their control of cement hydration.

  16. Coronal Discoloration Induced by Calcium-Enriched Mixture, Mineral Trioxide Aggregate and Calcium Hydroxide: A Spectrophotometric Analysis

    PubMed Central

    Esmaeili, Behnaz; Alaghehmand, Homayoun; Kordafshari, Tavoos; Daryakenari, Ghazaleh; Ehsani, Maryam; Bijani, Ali

    2016-01-01

    Introduction: The aim of this study was to compare the discoloration potential of calcium-enriched mixture (CEM) cement, white mineral trioxide aggregate (WMTA) and calcium hydroxide (CH), after placement in pulp chamber. Methods and Materials: Access cavities were prepared in 40 intact maxillary central incisors. Then, a 2×2 mm box was prepared on the middle third of the inner surface on the buccal wall of the access cavity. The specimens were randomly assigned into four groups; the boxes in the control group were left empty, in groups 1 to 3, the boxes were filled with CH, WMTA and CEM cement, respectively. The access cavities and the apical openings were sealed using resin modified glass ionomer (RMGI). The color measurement was performed with a spectrophotometer at the following intervals: before (T0), immediately after placement of the filling material (T1), one week (T2), 1 month (T3), 3 months (T4) and 5 months (T5) after filling of the box and finally immediately after removing the material from the boxes (T6). Color change (ΔE) values were calculated using the sample Kolmogorov-Smirnov test to determine the normal distribution of data, followed by ANOVA, repeated measured ANOVA and post-hoc Tukey’s tests. Results: All materials led to clinically perceptible crown discoloration after 1 week. The highest ΔE value belonged to WMTA group. Discoloration induced by CEM cement was not significantly different from CH or the control group (P>0.05). Conclusion: CEM cement may be the material of choice in the esthetic region, specifically pertaining to its lower color changing potential compared to WMTA. PMID:26843873

  17. Accelerated carbonation of Friedel's salt in calcium aluminate cement paste

    SciTech Connect

    Goni, S.; Guerrero, A

    2003-01-01

    The stability of Friedel's salt with respect to carbonation has been studied in calcium aluminate cement (CAC) pastes containing NaCl (3% of Cl{sup -} by weight of cement). Carbonation was carried out on a powdered sample in flowing 5% CO{sub 2} gas at 65% relative humidity to accelerate the process. At an intermediate carbonation step, a part of the sample was washed and dried up to 10 cycles to simulate a dynamic leaching attack. The two processes were followed by means of X-ray diffraction (XRD), pH and Cl{sup -} analyses in the simulated pore solution.

  18. An in vitro Comparison of Endodontic Medicaments Propolis and Calcium Hydroxide alone and in Combination with Ciprofloxacin and Moxifloxacin against Enterococcus Faecalis.

    PubMed

    Shrivastava, Rahul; Rai, Vivek Kumar; Kumar, Aina; Sinha, Sonal; Tripathi, Prerna; Gupta, Khushboo; Sabharwal, Sumit

    2015-05-01

    To evaluate and compare the antimicrobial properties of propolis and calcium hydroxide alone and in combination with ciprofloxacin and moxifloxacin against Enterococcus faecalis (E. Faecalis). The laboratory study was carried out to test the effectiveness of propolis and calcium hydroxidealone as well as in combination with the established endodontic medicaments (moxifloxacin and ciprofloxacin). The various combinations were-group 1: propolis, group 2: calcium hydroxide, group 3: moxifloxacin, group 4: ciprofoxacin, group 5: propolis + moxifloxacin, group 6: propolis + Ciprofloxacin, group 7: calcium hydroxide + ciprofloxacin, group 8: calcium hydroxide + moxifloxacin. The efficacy of these medicaments was tested by checking for the zone of inhibition for the specific strain (ATCC 29212) of E. faecalis at different time intervals, i.e. 24, 48 and 72 hours. Mean zone of inhibition was maximum in group V (21.94 ± 4.26) followed by group VI (18.80 ± 1.93), group I (18.71 ± 4.26), group VIII (15.88 ± 2.59), group III (14.91 ± 1.00), group VII (14.57 ± 2.17), group IV (13.91 ± 1.00) and minimum in group II (12.89 ± 2.14). Mean zone of inhibition was found to be maximum at 72 hours and minimum at 24 hours. At all time intervals, the combination of Propalis with Moxifocacin showed the maximum antimicrobial efficacy. On the basis of the results of the present study, it can be concluded that propolis and calcium hydroxide show synergistic effect with moxifloxacin and ciprofloxacin against E. Faecalis. Propolis in combination with antibiotics and alone is more effective than calcium hydroxide. Since propolis alone and in combination with antibiotics was observed to be more effective than calcium hydroxide, propolis can be considered as an intracanal medicament when compared to traditional calcium hydroxide.

  19. Novel microcalorimetric assay for antibacterial activity of implant coatings: The cases of silver-doped hydroxyapatite and calcium hydroxide.

    PubMed

    Braissant, Olivier; Chavanne, Philippe; de Wild, Michael; Pieles, Uwe; Stevanovic, Sabrina; Schumacher, Ralf; Straumann, Lukas; Wirz, Dieter; Gruner, Philipp; Bachmann, Alexander; Bonkat, Gernot

    2015-08-01

    Biomaterials with antimicrobial properties are now commonly used in different clinical specialties including orthopedics, endodontic, and traumatology. As a result, assessing the antimicrobial effect of coatings applied on implants is of critical importance. In this study, we demonstrate that isothermal microcalorimetry (IMC) can be used for monitoring bacterial growth and biofilm formation at the surface of such coatings and for determining their antimicrobial effects. The antibacterial effects of silver doped hydroxyapatite (HA) and calcium hydroxide coatings on Staphylococcus epidermidis were determined with a minimal workload. Using the Gompertz growth model we determined biofilm growth rates close to those values reported in the literature. Furthermore, we were able to estimate the reduction in the bacterial inocula originally applied at the surface of the coatings. Therefore, in addition to monitoring the antimicrobial effect of silver doped HA and calcium hydroxide coatings, we also demonstrate that IMC might be a valuable tool for assessing such antimicrobial properties of implant coatings at a minimal workload.

  20. Assessment of the Pozzolanic Activity of a Spent Catalyst by Conductivity Measurement of Aqueous Suspensions with Calcium Hydroxide

    PubMed Central

    Velázquez, Sergio; Monzó, José M.; Borrachero, María V.; Payá, Jordi

    2014-01-01

    The pozzolanic activity of the spent catalyst produced by fluid catalytic cracking (FCC) has been studied by various methods in recent years. However, no quick and easy method has been reported for this activity based on the associated studies. In this work, the pozzolanic activity of a spent catalyst was investigated by measuring its electrical conductivity in aqueous suspensions of pozzolan/calcium hydroxide. The behavior of the FCC catalyst residue was compared to that of reactive and inert materials of similar chemical compositions. Further, the influence of temperature on the suspension was studied, and also, a new method was proposed in which the pozzolan/calcium hydroxide ratio was varied (with the initial presence of solid Ca(OH)2 in the system). It was concluded that the method is effective, fast and simple for evaluating the high reactivity of the catalyst. Therefore, this method is an alternative for the evaluation of the reactivity of pozzolanic materials. PMID:28788583

  1. A 2-year follow-up of primary molars, pulpotomized with a gentle technique and capped with calcium hydroxide.

    PubMed

    Schröder, U

    1978-07-01

    The prognosis for pulpotomy of primary molars with calcium hydroxide as wound dressing was evaluated clinically and radiographically. Thirty-three primary mandibular molars were amputated under the following conditions: (1) chronic coronal pulpitis, (2) the amputation was done with diamond instruments and a high-speed machine under aseptic conditions, and (3) application of calcium hydroxide in contact with the wound surface. After 1 year the treatment was regarded as successful for 22 of the teeth (67%); 11 teeth showed internal dentin resorption. After 2 years the frequency of success, allowing for drop-out, was 59%. Internal dentin resorption was seen in 14 root canals; in 10 of them within the first 6 months. A histologic study of nine root pulps with internal dentin resorption revealed an extra-pulpal blood clot on the wound surface in five.

  2. Duration for apical barrier formation in necrotic immature permanent incisors treated with calcium hydroxide apexification using ultrasonic or hand filing.

    PubMed

    Lee, Li-Wan; Hsiao, Sheng-Huang; Chang, Chao-Ching; Chen, Li-Kai

    2010-08-01

    Traumatic injury usually results in pulp necrosis of immature permanent incisors in children aged 7-10 years. Calcium hydroxide apexification is the most common treatment for necrotic, immature permanent teeth. This study compared the duration for apical barrier formation in necrotic immature permanent incisors treated with calcium hydroxide apexification using ultrasonic or hand filing. Thirty-two trauma-induced necrotic immature permanent incisors with or without a periapical lesion (PL) were selected from children aged 7-10 years. They were evenly divided into four groups. Teeth in groups 1 (with PL) and 2 (without PL) were treated with ultrasonic filing, and teeth in groups 3 (with PL) and 4 (without PL) were treated with hand filing. The canals were cleaned with 0.2% chlorhexidine solution during treatment and then compactly filled with calcium hydroxide. The patients were followed up once every 1-3 weeks to change the intracanal medication and to detect when the apical barrier formed. The mean duration for apical barrier formation was 11.1 +/- 1.1 weeks, 11.8 +/- 1.0 weeks, 13.3+/-0.9 weeks and 13.4 +/- 0.7 weeks for groups 1, 2, 3 and 4, respectively. Student's t test showed significant differences in the mean duration for apical barrier formation between groups 1+2 and 3 + 4 (p = 0.000), groups 1 and 3 (p = 0.000), and groups 2 and 4 (p = 0.002). These results indicated that teeth treated with ultrasonic filing required a shorter mean duration for apical barrier formation than teeth treated with hand filing regardless of the presence of PL or not. Ultrasonic filing with 0.2% chlorhexidine as an irrigant is effective for disinfection of the root canal and can shorten the duration for apical barrier formation in necrotic permanent incisors treated with calcium hydroxide apexification. 2010 Formosan Medical Association & Elsevier. Published by Elsevier B.V. All rights reserved.

  3. Dual nutraceutical nanohybrids of folic acid and calcium containing layered double hydroxides

    NASA Astrophysics Data System (ADS)

    Kim, Tae-Hyun; Oh, Jae-Min

    2016-01-01

    Dual nutraceutical nanohybrids consisting of organic nutrient, folic acid (FA), and mineral nutrient, calcium, were prepared based on layered double hydroxide (LDH) structure. Among various hybridization methods such as coprecipitation, ion exchange, solid phase reaction and exfoliation-reassembly, it was found that exfoliation-reassembly was the most effective in terms of intercalation of FA moiety between Ca-containing LDH layers. X-ray diffraction patterns and infrared spectra indicated that FA molecules were well stabilized in the interlayer space of LDHs through electrostatic interaction. From the atomic force and scanning electron microscopic studies, particle thickness of LDH was determined to be varied with tens, a few and again tens of nanometers in pristine, exfoliated and reassembled state, respectively, while preserving particle diameter. The result confirmed layer-by-layer hybrid structure of FA and LDHs was obtained by exfoliation-reassembly. Solid UV-vis spectra showed 2-dimensional molecular arrangement of FA moiety in hybrid, exhibiting slight red shift in n→π* and π→π* transition. The chemical formulae of FA intercalated Ca-containing LDH were determined to Ca1.30Al(OH)4.6FA0.74·3.33H2O and Ca1.53Fe(OH)5.06FA2.24·9.94H2O by inductively coupled plasma-atomic emission spectroscopy, high performance liquid chromatography and thermogravimetry, showing high nutraceutical content of FA and Ca.

  4. Delayed tooth replantation following root canal filling with calcium hydroxide and MTA: Histomorphometric study in rats.

    PubMed

    Esteves, Jônatas Caldeira; Marão, Heloisa Fonseca; Silva, Pedro Ivo Dos Santos; Poi, Wilson Roberto; Panzarini, Sônia Regina; Aranega, Alessandra Marcondes; Ribeiro, Eduardo Dias; Sonoda, Celso Koogi

    2015-09-01

    The aim of this study was to perform a histomorphometric evaluation of the repair process in rat teeth replanted after root canals were filled with calcium hydroxide (CH) and mineral trioxide aggregate (MTA). Upper right incisors were extracted from 30 rats divided into three groups (n=10). The teeth were stored dry for 60min, after which the pulp and periodontal ligament (PDL) were removed and immersed in acidulated-phosphate sodium fluoride solution. In Group I, the root canals were filled with saline; in Group II, they were filled with CH; and in Group III, they were filled with CH, and the foramen was sealed with an MTA plug. The teeth were replanted, and the animals were sacrificed after 60 days. The sections with teeth were removed for histological preparation (haematoxylin and eosin, H&E). The characteristics of the PDL, cementum, dentine, and alveolar bone, as well as the occurrence of inflammatory and replacement root resorption and apical sealing, were subjected to histological and morphometric analysis (P<0.05). Group I was the most affected by root resorption (mean=67.05%). In Groups II and III, the resorption averaged 42.2% and 11.7%, respectively. Group III was less affected by inflammatory resorption and presented more areas of apical sealing by mineralized tissue (P<0.05). An apical MTA plug improved the repair of the replanted tooth by decreasing surface resorption and repairing mineralized tissue in the periapical region. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Antimicrobial efficacy of octenidine hydrochloride, MTAD and chlorhexidine gluconate mixed with calcium hydroxide.

    PubMed

    Tirali, Resmiye Ebru; Gulsahi, Kamran; Cehreli, Sevi Burcak; Karahan, Zeynep Ceren; Uzunoğlu, Emel; Elhan, Atilla

    2013-05-01

    The aim of this in vitro study was to investigate whether mixing with calcium hydroxide [Ca(OH)2] affects the antimicrobial action of Octenidine hydrochloride (Octenisept), MTAD and chlorhexidine against Enterococcus faecalis and Candida albicans. Freshly grown cultures of Enterococcus faecalis, Candida albicans and a mixture of both strains were incubated in agar plates containing brain-heart infusion broth (BHIB). Zones of inhibition were measured at 24 and 48 hours. Statistical analysis was performed using Mann-Whitney U test and Kruskal-Wallis one-way analysis of variance (ANOVA, both p=0.05). Mixing with Ca(OH)2 significantly increased the antibacterial effect of Octenisept (p<0.05), but did not alter its antifungal activity. Only chlorhexidine showed more antibacterial and antifungal efficiency compared to its Ca(OH)2-mixed version (both p<0.05). Mixing with Ca(OH)2 decreased the antibacterial efficacy of MTAD, but increased its antifungal effect (both p<0.05). These results demonstrate the differential effects of Ca(OH)2 addition on the antimicrobial action of the tested endodontic medicaments in vitro. Ca(OH)2 was as effective as its combination with all of the tested medicaments.

  6. Microleakage of glass-ionomer cement placed in association with non-setting calcium hydroxide.

    PubMed

    Mahmood, S A; Wood, D J; Boyle, E L; Jarad, F D; Youngson, C C

    2005-05-01

    The purpose of this investigation was to determine whether non-setting calcium hydroxide [Ca (OH)2] cement placed in the root canal system of premolar teeth would affect the subsequent microleakage of a glass-ionomer restoration (GIC). Following selection, 62 human premolar teeth extracted for orthodontic reasons were accessed and root canals prepared according to a standardized procedure. The specimens were then allocated randomly into two major groups each of 30 teeth. Two other teeth were used as a positive and a negative control. The control group was restored with glass-ionomer cement following drying of the canal and placement of a cotton wool pledget. The test group had all canals dressed with non-setting Ca(OH)2 and then was subdivided, one set (n = 22) being restored following conditioning of the access cavity margins, the other (n = 8) having the margins cleaned with a hand excavator. Samples were assessed for microleakage using a two-point scoring system (leakage or no leakage) in conjunction with a clearing technique using AgNO3. Using Fisher's exact test, a statistically significant difference was found between the control and test groups (P < 0.05) but there was no significant difference between the excavated and conditioned cavities (P=0.55). It is concluded that contamination of access cavity margins with Ca(OH)2 during medication of a root canal interferes with the bond of GIC, resulting in increased microleakage in vitro.

  7. Subcutaneous tissue reaction to castor oil bean and calcium hydroxide in rats

    PubMed Central

    CAMARGO, Samira Esteves Afonso; RODE, Sigmar de Mello; do PRADO, Renata Falchete; CARVALHO, Yasmin Rodarte; CAMARGO, Carlos Henrique Ribeiro

    2010-01-01

    Castor oil bean cement (COB) is a new material that has been used as an endodontic sealer, and is a candidate material for direct pulp capping. Objective The purpose of this study was to evaluate the biocompatibility of a new formulation of COB compared to calcium hydroxide cement (CH) and a control group without any material, in the subcutaneous tissue of rats. Material and methods The materials were prepared, packed into polyethylene tubes, and implanted in the rat dorsal subcutaneous tissue. Animals were sacrificed at the 7th and 50th days after implantation. A quantitative analysis of inflammatory cells was performed and data were subjected to ANOVA and Tukey's tests at 5% significance level. Results Comparing the mean number of inflammatory cells between the two experimental groups (COB and CH) and the control group, statistically significant difference (p=0.0001) was observed at 7 and 50 days. There were no significant differences (p=0.111) between tissue reaction to CH (382 inflammatory cells) and COB (330 inflammatory cells) after 7 days. After 50 days, significantly more inflammatory cells (p=0.02) were observed in the CH group (404 inflammatory cells) than in the COB group (177 inflammatory cells). Conclusions These results demonstrate that the COB cement induces less inflammatory response within long periods. PMID:20857007

  8. [Acute effect of calcium hydroxide-containing material in the rat's dental pulp microcirculation].

    PubMed

    Grigár, A; Iványi, I; Balogh, A E; Rosivall, L; Nyárasdy, I

    2001-06-01

    Experimental stimulation and clinical procedures applied on the crown of the tooth cause vascular reaction in the dental pulp. Laser-Doppler flowmetry is a good method for determining the blood flow of the dental pulp. The aim of these experiments was to study the acute effect of a calcium hydroxide-containing pulp-capping material (Dycal, DeTrey) on blood flow of the dental pulp after the application into a deep test-cavity. Two groups of male Sprague-Dawley rats (308 g +/- 50 S.E.) were used: control- and test-group, n = 10. A standardised deep class five cavity was prepared in the left lower incisor of each rat. Laser-Doppler flowmeter was used to measure the vascular reaction of the pulp. The levels of blood flow were recorded prior to (0 min.) and after the application (1, 5, 15, 30, 60 min.) of Dycal. Results were evaluated with one-way ANOVA. Significantly higher pulpal blood flow was found only in the first minute after the application of Dycal. In any other time no significant difference was found between the results before and after (5, 15, 30, 60 min.) the application in test- and control-group.

  9. Antimicrobial Activity of Calcium Hydroxide and Betamethasone on Enterococcus faecalis; An in vitro Assessment

    PubMed Central

    Tabrizizadeh, Mahdi; Rasti, Mojtaba; Ayatollahi, Fatemeh; Mossadegh, Mohammad Hossein; Zandi, Hengameh; Dehghan, Farzad; Mousavi, Zohreh

    2015-01-01

    Introduction: Calcium hydroxide (CH) is one of the most common intracanal medications. Corticosteroids (CS) are used in endodontics because of their anti-inflammatory activity. This study aimed to evaluate the antimicrobial effect of CH+betamethasone and CH+saline against Enterococcus faecalis (E. faecalis) using agar diffusion test and measuring the microbial zone of inhibition (ZOI). Methods and Materials: Four plates containing Mueller-Hinton broth and E. faecalis culture media, were prepared. In each plate, 5 holes (5×3 mm) were created and a creamy mixture of CH+betamethasone was inserted into the holes (10 holes for each material). Two holes with ampicillin disks and two empty holes were used as negative and positive controls, respectively. Plates were incubated for 24 h and then the diameter of microbial ZOI was measured. The pH of each mixture was measured by pH meter. Data were analyzed using the Mann-Whitney U test. Results: The mean diameter of ZOI for CH+betamethasone and CH+saline was 3.4 and 3 mm, respectively. The difference was not significant (P=0.143). The pH was 12.5 for CH+saline and 12.3 CH+betamethasone, respectively. Conclusion: The mixture of CH+betamethasone had good antimicrobial effects against E. faecalis. Further studies are needed to confirm the value of this mixture in clinical settings. PMID:26213541

  10. Nestin expressions of exposed pulp after direct pulp capping by calcium hydroxide and platelet rich plasma

    PubMed Central

    Puspita, Sartika; Utoro, Totok; Haniastuti, Tetiana

    2016-01-01

    Objective: The aim of this study was to evaluate nestin expression of pulp tissue following direct pulp capping with platelet-rich plasma (PRP). Materials and Methods: The thirty sound teeth from Sprague-Dawley rats were used and divided into two groups: Groups 1, teeth were capped with calcium hydroxide/Ca(OH)2 (n = 15) and Group 2 with PRP (n = 15). After 1st, 7th, and 21st days, respectively, 5 teeth each group (American Dental Association 41) were processed for light microscopic examination. Expressions of nestin were assessed by immunohistochemical techniques. Results: Nestin expression of Ca(OH)2 on the distance place of exposure at 1st and 7th days were 80% and at 21st day were 60%. Nestin expression of PRP on the distance place at 1st day was 80%, 7th 100%, and 21st day was 80%. At day 21 observation, Kruskal–Wallis test shows nestin expression was increased significantly in PRP groups (P < 0.05), but it was not increase significantly compare with Ca(OH)2. Conclusion: PRP had ability as a direct pulp capping material to induce nestin expression. PMID:27403050

  11. 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.

  12. Evaluation of formocresol, calcium hydroxide, ferric sulfate, and MTA primary molar pulpotomies.

    PubMed

    Yildiz, Esma; Tosun, Gul

    2014-04-01

    The aim of this study is to evaluate four different pulpotomy medicaments in primary molars. A total of 147 primary molars with deep caries were treated with four different pulpotomy medicaments (FC: formocresol, FS: ferric sulfate, CH: calcium hydroxide, and MTA: mineral trioxide aggregate) in this study. The criteria for tooth selection for inclusion were no clinical and radiographic evidence of pulp pathology. During 30 months of follow-up at 6-month intervals, clinical and radiographic success and failures were recorded. The differences between the groups were statistically analyzed using the Chi-square test and Kaplan-Meier analysis. At 30 months, clinical success rates were 100%, 95.2%, 96.4%, and 85% in the FC, FS, MTA, and CH groups, respectively. In radiographic analysis, the MTA group had the highest (96.4%), and the CH group had the lowest success rate (85%). There were no clinical and radiographic differences between materials (P > 0.05). Although there were no differences between materials, only in the CH group did three teeth require extraction due to further clinical symptoms of radiographic failures during the 30-month follow-up period. None of the failed teeth in the other groups required extraction during the 30-month follow-up period.

  13. Evaluation of formocresol, calcium hydroxide, ferric sulfate, and MTA primary molar pulpotomies

    PubMed Central

    Yildiz, Esma; Tosun, Gul

    2014-01-01

    Objective: The aim of this study is to evaluate four different pulpotomy medicaments in primary molars. Materials and Methods: A total of 147 primary molars with deep caries were treated with four different pulpotomy medicaments (FC: formocresol, FS: ferric sulfate, CH: calcium hydroxide, and MTA: mineral trioxide aggregate) in this study. The criteria for tooth selection for inclusion were no clinical and radiographic evidence of pulp pathology. During 30 months of follow-up at 6-month intervals, clinical and radiographic success and failures were recorded. The differences between the groups were statistically analyzed using the Chi-square test and Kaplan-Meier analysis. Results: At 30 months, clinical success rates were 100%, 95.2%, 96.4%, and 85% in the FC, FS, MTA, and CH groups, respectively. In radiographic analysis, the MTA group had the highest (96.4%), and the CH group had the lowest success rate (85%). There were no clinical and radiographic differences between materials (P > 0.05). Conclusions: Although there were no differences between materials, only in the CH group did three teeth require extraction due to further clinical symptoms of radiographic failures during the 30-month follow-up period. None of the failed teeth in the other groups required extraction during the 30-month follow-up period. PMID:24966776

  14. Study Comparing the Effectiveness of Chlorhexidine, Calcium Hydroxide and Linezolid Based Medicaments Against Enterococcus Faecalis

    PubMed Central

    Pavaskar, Rajdeep; Chalakkal, Paul; Krishnan, Ramesh; Sirikonda, Saritha; Vasepalli, Madhu; Venkataramana, Pammi

    2014-01-01

    Purpose: This study evaluated the efficacy of 2% chlorhexidine (CX), calcium hydroxide (CH), Vitapex® (VP), linezolid (LZ), a combination of LZ with CH (LC) against Enterococcus faecalis (EF). Study Design: EF strains were mixed with peptone water and the turbidity was adjusted to the McFarland’s turbidity standard tube No: 0.5. The inoculum obtained was used to make lawn cultures on the agar plates. A total of 30 agar plates were prepared, such that each plate had five wells containing the five medicaments. The plates were incubated and evaluated for zones of inhibition after intervals of 24 hours and 72 hours. The results were statistically evaluated by paired t-test, ANOVA and Post-hoc analysis using Tukey’s HSD. Results: The difference between values of the zones of inhibition around various medicaments after 24 hours and 72 hours was found to be statistically significant. A comparison between the five groups after 24 hours or 72 hours showed that each group differed significantly from the rest of the groups. Conclusions: LC had the greatest effectiveness against EF, followed by LZ, CX, VP and CH. PMID:24783147

  15. Accidental injury of the inferior alveolar nerve due to the extrusion of calcium hydroxide in endodontic treatment: a case report

    PubMed Central

    2016-01-01

    During clinical endodontic treatment, we often find radiopaque filling material beyond the root apex. Accidental extrusion of calcium hydroxide could cause the injury of inferior alveolar nerve, such as paresthesia or continuous inflammatory response. This case report presents the extrusion of calcium hydroxide and treatment procedures including surgical intervention. A 48 yr old female patient experienced Calcipex II extrusion in to the inferior alveolar canal on left mandibular area during endodontic treatment. After completion of endodontic treatment on left mandibular first molar, surgical intervention was planned under general anesthesia. After cortical bone osteotomy and debridement, neuroma resection and neurorrhaphy was performed, and prognosis was observed. But no improvement in sensory nerve was seen following surgical intervention after 20 mon. A clinician should be aware of extrusion of intracanal medicaments and the possibility of damage on inferior alveolar canal. Injectable type of calcium hydroxide should be applied with care for preventing nerve injury. The alternative delivery method such as lentulo spiral was suggested on the posterior mandibular molar. PMID:26877992

  16. Calcium hydroxide as a processing base in alkali-aided pH-shift protein recovery process.

    PubMed

    Paker, Ilgin; Jaczynski, Jacek; Matak, Kristen E

    2017-02-01

    Protein may be recovered by using pH shifts to solubilize and precipitate protein. Typically, sodium hydroxide is used as the processing base; however, this has been shown to significantly increase sodium in the final recovered protein. Protein was extracted from black bullhead catfish (Ameiurus melas) using a pH-shift method. Protein was solubilized using either sodium hydroxide (NaOH) or calcium hydroxide (Ca(OH)2 ) and precipitated at pH 5.5 using hydrochloric acid (HCl). Protein solubility was greater when Ca(OH)2 was used compared to NaOH during this process. Using Ca(OH)2 as the processing base yielded the greatest lipid recovery (P < 0.05) at 77 g 100 g(-1) , whereas the greatest (P < 0.05) protein recovery yield was recorded as 53 g 100 g(-1) protein using NaOH. Protein solubilized with Ca(OH)2 had more (P < 0.05) calcium in the protein fraction, whereas using NaOH increased (P < 0.05) sodium content. Results of our study showed that protein solubility was increased and the recovered protein had significantly more calcium when Ca(OH)2 was used as the processing base. Results showed both NaOH and Ca(OH)2 to be an effective processing base for pH-shift protein recovery processes. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  17. Clinical evaluation of glutaraldehyde with calcium hydroxide and glutaraldehyde with zinc oxide eugenol in pulpotomy of primary molars.

    PubMed

    Shumayrikh, N M; Adenubi, J O

    1999-12-01

    The objectives of this study were to clinically evaluate the effectiveness of 2% buffered glutaraldehyde in pulpotomies of human primary molars and to compare the success rate of glutaraldehyde with calcium hydroxide and glutaraldehyde with zinc oxide eugenol as dressing material on the radicular pulp. Pulpotomies were completed on 61 primary molars in 19 children. The teeth were divided into two groups by random allocation. One group had a dressing of zinc oxide-eugenol base (IRM) incorporated with one drop of 2% buffered glutaraldehyde while the other group had a dressing of calcium hydroxide base incorporated with one drop of 2% buffered glutaraldehyde after the initial placement of 2% buffered glutaraldehyde on cotton pellet for 3 min. All teeth had light-curing compomer (Dyract) placed over the dressing material followed by a stainless steel crown restoration within 1 or 2 weeks after the pulpotomy. Blind clinical and radiographic evaluations of 57 teeth available after 12 months showed a success rate of 92.9% and 73.6% respectively. The clinical and radiographic success rates for glutaraldehyde/zinc oxide eugenol pulpotomies were 96.5% and 75.8% respectively while those for glutaraldehyde-calcium hydroxide were 89.2% and 71.4%. There was no statistically significant difference between the two groups either clinically or radiographically. The overall clinical success rate suggested that 2% buffered glutaraldehyde was an effective agent in the pulpotomy of human primary molars.

  18. Accidental injury of the inferior alveolar nerve due to the extrusion of calcium hydroxide in endodontic treatment: a case report.

    PubMed

    Shin, Yooseok; Roh, Byoung-Duck; Kim, Yemi; Kim, Taehyeon; Kim, Hyungjun

    2016-02-01

    During clinical endodontic treatment, we often find radiopaque filling material beyond the root apex. Accidental extrusion of calcium hydroxide could cause the injury of inferior alveolar nerve, such as paresthesia or continuous inflammatory response. This case report presents the extrusion of calcium hydroxide and treatment procedures including surgical intervention. A 48 yr old female patient experienced Calcipex II extrusion in to the inferior alveolar canal on left mandibular area during endodontic treatment. After completion of endodontic treatment on left mandibular first molar, surgical intervention was planned under general anesthesia. After cortical bone osteotomy and debridement, neuroma resection and neurorrhaphy was performed, and prognosis was observed. But no improvement in sensory nerve was seen following surgical intervention after 20 mon. A clinician should be aware of extrusion of intracanal medicaments and the possibility of damage on inferior alveolar canal. Injectable type of calcium hydroxide should be applied with care for preventing nerve injury. The alternative delivery method such as lentulo spiral was suggested on the posterior mandibular molar.

  19. Effect of Previous Calcium Hydroxide Dressing on the Sealing Properties of the New Endodontic Cement Apical Barrier

    PubMed Central

    Bidar, Maryam; Disfani, Reza; Gharagozlo, Salman; Rouhani, Armita; Forghani, Maryam

    2011-01-01

    Objectives: Using the fluid filtration method, an in vitro study was conducted to evaluate the effects of medication with calcium hydroxide on the sealing ability of the New Endodontic Cement (NEC) apical barrier in the short and long terms. Methods: Fifty extracted single rooted teeth were prepared and apical resorption produced using acid sulfuric for four days. The teeth were randomly divided into two experimental groups (n=20) and two control groups. In group 1, calcium hydroxide was placed into all canals for one week and in group 2, no medication was used. In both groups, a 4 mm NEC apical plug was placed in the canals and the remaining portion of the canals was filled with gutta-percha. The amount of microleakage of all samples was evaluated after one week and three months. The data were statistically analyzed using two-way ANOVA. Results: There was no significant difference between the two groups in either time period (P>.05). In both group 1 and group 2, microleakage increased after three months but this increase was not statistically significant (P>.05). Conclusions: According to the result of this study, medication with calcium hydroxide had no adverse effect on the short- and long-term sealing properties of an NEC apical plug. PMID:21769266

  20. Evaluation of mineral trioxide aggregate (MTA) versus calcium hydroxide cement (Dycal(®) ) in the formation of a dentine bridge: a randomised controlled trial.

    PubMed

    Leye Benoist, Fatou; Gaye Ndiaye, Fatou; Kane, Abdoul Wakhabe; Benoist, Henri Michel; Farge, Pierre

    2012-02-01

    To assess the effectiveness of mineral trioxide aggregate (MTA) used as an indirect pulp-capping material in human molar and premolar teeth. We conducted a clinical evaluation of 60 teeth, which underwent an indirect pulp-capping procedure with either MTA or calcium hydroxide cement (Dycal(®) ). Calcium hydroxide was compared with MTA and the thickness of the newly formed dentine was measured at regular time intervals. The follow-up was at 3 and 6 months, and dentine formation was monitored by radiological measurements on digitised images using Mesurim Pro(®) software. At 3 months, the clinical success rates of MTA and calcium hydroxide were 93% and 73%, respectively (P = 0.02). At 6 months, the success rate was 89.6% with MTA, and remained steady at 73% with calcium hydroxide (P = 0.63). The mean initial residual dentine thickness was 0.23 mm, and increased by 0.121 mm with MTA and by 0.136 mm with calcium hydroxide at 3 months. At 6 months, there was an increase of 0.235 mm with MTA and of 0.221 mm with calcium hydroxide.   A higher success rate was observed in the MTA group relative to the Dycal(®) group after 3 months, which was statistically significant. After 6 months, no statistically significant difference was found in the dentine thickness between the two groups. Additional histological investigations are needed to support these findings. © 2012 FDI World Dental Federation.

  1. Efficacy of 3 different irrigation systems on removal of calcium hydroxide from the root canal: a scanning electron microscopic study.

    PubMed

    Alturaiki, Sami; Lamphon, Hebah; Edrees, Hadeel; Ahlquist, Michael

    2015-01-01

    The purpose of this study was to evaluate the effectiveness of different irrigation systems on removing calcium hydroxide (Ca[OH]2) from the root canal by using a scanning electron microscope. Forty extracted single-rooted teeth were divided randomly into 4 groups. Canal instrumentation was done, and the teeth were filled with Ca(OH)2 paste. One week later, 4 techniques were used for Ca(OH)2 removal. In the first group, the canals were cleaned with a master apical file. The second, third, and fourth groups were irrigated using the EndoVac (Discus Dental, Culver City, CA), EndoActivator (Dentsply Tulsa Dental Specialties, Tulsa, OK), and ProUltra (Dentsply Tulsa, Tulsa, OK) systems, respectively. All the groups were irrigated with 3 mL (18%) EDTA and 3 mL (1%) NaOCl for 1 minute. The canal walls were viewed, and the remaining amount of Ca(OH)2 was evaluated using a scanning electron microscope. A scoring system was used to assess the amount of residue Ca(OH)2 on each third of the canal. The obtained data for comparisons between the conventional irrigation needle and each device were statistically analyzed using the Mann-Whitney U test. To compare the 4 devices, the results were statistically analyzed using the analysis of variance test. None of the investigated techniques removed the Ca(OH)2 dressing completely. However, the EndoActivator System showed better results in removing Ca(OH)2 in each third of the root canals in comparison with the other techniques. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  2. A novel approach for stabilizing fresh urine by calcium hydroxide addition

    PubMed Central

    Randall, Dyllon G.; Krähenbühl, Manuel; Köpping, Isabell; Larsen, Tove A.; Udert, Kai M.

    2016-01-01

    In this study, we investigated the prevention of enzymatic urea hydrolysis in fresh urine by increasing the pH with calcium hydroxide (Ca(OH)2) powder. The amount of Ca(OH)2 dissolving in fresh urine depends significantly on the composition of the urine. The different urine compositions used in our simulations showed that between 4.3 and 5.8 g Ca(OH)2 dissolved in 1 L of urine at 25 °C. At this temperature, the pH at saturation is 12.5 and is far above the pH of 11, which we identified as the upper limit for enzymatic urea hydrolysis. However, temperature has a strong effect on the saturation pH, with higher values being achieved at lower temperatures. Based on our results, we recommend a dosage of 10 g Ca(OH)2 L−1 of fresh urine to ensure solid Ca(OH)2 always remains in the urine reactor which ensures sufficiently high pH values. Besides providing sufficient Ca(OH)2, the temperature has to be kept in a certain range to prevent chemical urea hydrolysis. At temperatures below 14 °C, the saturation pH is higher than 13, which favors chemical urea hydrolysis. We chose a precautionary upper temperature of 40 °C because the rate of chemical urea hydrolysis increases at higher temperatures but this should be confirmed with kinetic studies. By considering the boundaries for pH and temperature developed in this study, urine can be stabilized effectively with Ca(OH)2 thereby simplifying later treatment processes or making direct use easier. PMID:27055084

  3. Effect of rotary instrument associated with different irrigation techniques on removing calcium hydroxide dressing.

    PubMed

    Faria, Gisele; Viola, Kennia Scapin; Kuga, Milton Carlos; Garcia, Arturo Javier Aranda; Daher, Vanessa Bossolani; De Pasquali Leonardo, Mário Francisco; Tanomaru-Filho, Mário

    2014-08-01

    Calcium hydroxide [Ca(OH)2 ] residues in root canals may compromise sealing of filling and endodontic treatment success. The aim of this study was to compare the efficacy of using rotary instrument associated with EndoActivator, EndoVac, passive ultrasonic irrigation (PUI), and conventional needle irrigation (CNI), in Ca(OH)2 removal from root canal, by means of scanning electron microscopy (SEM) images. Sixty-six human canines were prepared with the Protaper system up to F5 and filled with Ca(OH)2 . After 7 days, Ca(OH)2 was removed with rotary instrument F5 associated with the irrigation techniques used in each group (n = 15): GI (CNI), GII (EndoVac), GIII (EndoActivator) and GIV (PUI). In all groups 15 mL of 2.5% NaOCl and 3 mL of 17% EDTA were used for Ca(OH)2 removal. The Ca(OH)2 residues was evaluated by SEM in the middle and apical third using a system of scores. The results were analyzed by the Kruskal-Wallis and Dunn tests (α = 0.05). None of the techniques completely removed the Ca(OH)2 from root canals. There was no difference between EndoActivator, EndoVac and PUI (P > 0.05), but the three techniques removed more Ca(OH)2 than the CNI (P < 0,05), in the middle and apical thirds of the root canal. It was concluded that the rotary instrument combined with EndoActivator, EndoVac, and PUI was shown to be more efficient than the rotary instrument combined with the CNI in removing Ca(OH)2 from the root canal.

  4. Dual nutraceutical nanohybrids of folic acid and calcium containing layered double hydroxides

    SciTech Connect

    Kim, Tae-Hyun; Oh, Jae-Min

    2016-01-15

    Dual nutraceutical nanohybrids consisting of organic nutrient, folic acid (FA), and mineral nutrient, calcium, were prepared based on layered double hydroxide (LDH) structure. Among various hybridization methods such as coprecipitation, ion exchange, solid phase reaction and exfoliation-reassembly, it was found that exfoliation-reassembly was the most effective in terms of intercalation of FA moiety between Ca-containing LDH layers. X-ray diffraction patterns and infrared spectra indicated that FA molecules were well stabilized in the interlayer space of LDHs through electrostatic interaction. From the atomic force and scanning electron microscopic studies, particle thickness of LDH was determined to be varied with tens, a few and again tens of nanometers in pristine, exfoliated and reassembled state, respectively, while preserving particle diameter. The result confirmed layer-by-layer hybrid structure of FA and LDHs was obtained by exfoliation-reassembly. Solid UV–vis spectra showed 2-dimensional molecular arrangement of FA moiety in hybrid, exhibiting slight red shift in n→π* and π→π* transition. The chemical formulae of FA intercalated Ca-containing LDH were determined to Ca{sub 1.30}Al(OH){sub 4.6}FA{sub 0.74}·3.33H{sub 2}O and Ca{sub 1.53}Fe(OH){sub 5.06}FA{sub 2.24}·9.94H{sub 2}O by inductively coupled plasma-atomic emission spectroscopy, high performance liquid chromatography and thermogravimetry, showing high nutraceutical content of FA and Ca. - Highlights: • We successfully intercalated FA molecules into Ca-containing LDHs. • Exfoliation-reassembly was proven to be the most effective. • The interaction between LDH and FA were studied by FT-IR and UV–vis spectra. • Thermal stability of FA were enhanced by electrostatic interaction with LDH layers.

  5. Effectiveness of various irrigation protocols for the removal of calcium hydroxide from artificial standardized grooves

    PubMed Central

    GOKTURK, Hakan; OZKOCAK, Ismail; BUYUKGEBIZ, Feyzi; DEMIR, Osman

    2017-01-01

    Abstract Objective The aim of this study was to investigate the ability of laser-activated irrigation (LAI), XP-endo Finisher, CanalBrush, Vibringe, passive ultrasonic irrigation (PUI), and conventional syringe irrigation systems on the removal of calcium hydroxide (CH) from simulated root canal irregularities. Material and Methods The root canals of one hundred and five extracted single-rooted teeth were instrumented using Reciproc rotary files up to size R40. The teeth were split longitudinally. Two of the three standard grooves were created in the coronal and apical section of one segment, and another in the middle part of the second segment. The standardized grooves were filled with CH and the root halves were reassembled. After 14 days, the specimens were randomly divided into 7 experimental groups (n=15/group). CH was removed as follows: Group 1: beveled needle irrigation; Group 2: double side-vented needle irrigation; Group 3: CanalBrush; Group 4: XP-endo Finisher; Group 5: Vibringe; Group 6: PUI; Group 7: LAI. The amount of remaining CH in the grooves was scored under a stereomicroscope at 20× magnification. Statistical evaluation was performed using Kruskal–Wallis and Bonferroni-Correction Mann–Whitney U tests. Results Groups 1 and 2 were the least efficient in eliminating CH from the grooves. Groups 6 and 7 eliminated more CH than the other protocols; however, no significant differences were found between these two groups (P>.05). Conclusions Nevertheless, none of the investigated protocols were able to completely remove all CH from all three root regions. LAI and PUI showed less residual CH than the other protocols from artificial grooves. PMID:28678948

  6. Effectiveness of various irrigation protocols for the removal of calcium hydroxide from artificial standardized grooves.

    PubMed

    Gokturk, Hakan; Ozkocak, Ismail; Buyukgebiz, Feyzi; Demir, Osman

    2017-01-01

    The aim of this study was to investigate the ability of laser-activated irrigation (LAI), XP-endo Finisher, CanalBrush, Vibringe, passive ultrasonic irrigation (PUI), and conventional syringe irrigation systems on the removal of calcium hydroxide (CH) from simulated root canal irregularities. The root canals of one hundred and five extracted single-rooted teeth were instrumented using Reciproc rotary files up to size R40. The teeth were split longitudinally. Two of the three standard grooves were created in the coronal and apical section of one segment, and another in the middle part of the second segment. The standardized grooves were filled with CH and the root halves were reassembled. After 14 days, the specimens were randomly divided into 7 experimental groups (n=15/group). CH was removed as follows: Group 1: beveled needle irrigation; Group 2: double side-vented needle irrigation; Group 3: CanalBrush; Group 4: XP-endo Finisher; Group 5: Vibringe; Group 6: PUI; Group 7: LAI. The amount of remaining CH in the grooves was scored under a stereomicroscope at 20× magnification. Statistical evaluation was performed using Kruskal-Wallis and Bonferroni-Correction Mann-Whitney U tests. Groups 1 and 2 were the least efficient in eliminating CH from the grooves. Groups 6 and 7 eliminated more CH than the other protocols; however, no significant differences were found between these two groups (P>.05). Nevertheless, none of the investigated protocols were able to completely remove all CH from all three root regions. LAI and PUI showed less residual CH than the other protocols from artificial grooves.

  7. Removal efficiency of calcium hydroxide dressing from the root canal without chemically active adjuvant.

    PubMed

    Maalouf, Lara; Zogheib, Carla; Naaman, Alfred

    2013-03-01

    Compare the efficiency in removing two calcium hydroxide [Ca(OH)2] preparations from root canal and apical third using single use syringe, ultrasonics and RinsEndo((®)) with saline solution. One hundred and eighty human singlerooted teeth were instrumented using ProTaper((®)) rotary system, divided into two groups according to Ca(OH)2 filling. A: Powder mixed with water, B: Pulpdent((®)). Each group was divided into three subgroups for the irrigation: A1, B1: Single use syringe; A2, B2: Ultrasonics; A3, B3: RinsEndo((®)). Teeth were split longitudinally, photographed and imported into Adobe Photoshop. The percentage ratios of Ca(OH)2 remaining in the canal and in the apical third were calculated. Data were statistically analyzed using 'ANOVA two-way' and 'univariate tests'. (a) Remnants of medicament were found in all teeth, (b) no statistically significant difference in the elimination of both Ca(OH)2 from the entire canal (p = 0.436), however, mixed powder was better eliminated from the apical third (p = 0.005), (c) no statistically significant difference among the irrigation techniques in the whole canal (p = 0.608), though, RinsEndo((®)) and ultrasonics were the most effective in cleaning the apical third (p = 0.032) when mixed powder was used. None of the techniques removed completely Ca(OH)2 from the canal. In the apical third, RinsEndo((®)) and ultrasonics were the most effective when mixed powder was used. Ca(OH)2, the most commonly used intracanal dressing, should be completely eliminated before the obturation to assure a good endodontic sealing. Based on the results of this study, RinsEndo((®)) and ultrasonics were the most effective in removal of Ca(OH)2 especially the powder mixed with water presentation.

  8. A novel approach for stabilizing fresh urine by calcium hydroxide addition.

    PubMed

    Randall, Dyllon G; Krähenbühl, Manuel; Köpping, Isabell; Larsen, Tove A; Udert, Kai M

    2016-05-15

    In this study, we investigated the prevention of enzymatic urea hydrolysis in fresh urine by increasing the pH with calcium hydroxide (Ca(OH)2) powder. The amount of Ca(OH)2 dissolving in fresh urine depends significantly on the composition of the urine. The different urine compositions used in our simulations showed that between 4.3 and 5.8 g Ca(OH)2 dissolved in 1 L of urine at 25 °C. At this temperature, the pH at saturation is 12.5 and is far above the pH of 11, which we identified as the upper limit for enzymatic urea hydrolysis. However, temperature has a strong effect on the saturation pH, with higher values being achieved at lower temperatures. Based on our results, we recommend a dosage of 10 g Ca(OH)2 L(-1) of fresh urine to ensure solid Ca(OH)2 always remains in the urine reactor which ensures sufficiently high pH values. Besides providing sufficient Ca(OH)2, the temperature has to be kept in a certain range to prevent chemical urea hydrolysis. At temperatures below 14 °C, the saturation pH is higher than 13, which favors chemical urea hydrolysis. We chose a precautionary upper temperature of 40 °C because the rate of chemical urea hydrolysis increases at higher temperatures but this should be confirmed with kinetic studies. By considering the boundaries for pH and temperature developed in this study, urine can be stabilized effectively with Ca(OH)2 thereby simplifying later treatment processes or making direct use easier. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Review suggests direct pulp capping with MTA more effective than calcium hydroxide.

    PubMed

    Rasaratnam, Lakshmi

    2016-09-01

    Data sourcesPubMed, the Cochrane Library, Embase, and the Web of Knowledge.Study selectionRandomised controlled trials (RCTs) or retrospective non-randomised trials (RNTs) of direct pulp capping in patients comparing mineral trioxide aggregate (MTA) with calcium hydroxide (CH) were considered.Data extraction and synthesisTwo reviewers independently abstracted data. Risk of bias for the RCTs was assessed using the Cochrane risk of bias tool and RNTs were assessed according to the methodological index for non-randomised studies. Different study designs were analysed separately.ResultsThirteen studies were included, ten of which were RCTs. Meta-analysis demonstrated a significantly higher success rate for MTA compared with the CH-capped groups. For RCT studies (2 studies, 405 teeth): OR = 2.26; (95% CI, 1.33-3.85; P = .003) and for RNTs (3 studies - 526 teeth): OR = 2.88; (95% CI, 1.86-4.44; P < .00001). Nine studies (325 teeth) compared the inflammatory response with MTA showing significantly less inflammation compared with CH samples (OR = 4.56; 95% CI, 2.65 7.83; P < .00001). Nine studies (325 teeth) compared dentine bridge formation with a higher percentage of calcified dentin bridge formation in the MTA than CH-capped groups (OR = 3.56; 95% CI, 1.89 6.70; P < .0001).ConclusionsMTA has a higher success rate and results in less pulpal inflammatory response and more predictable hard dentin bridge formation than CH. MTA appears to be a suitable replacement of CH used for direct pulp capping.

  10. Newly developed resinous direct pulp capping agent containing calcium hydroxide (MTYA1-Ca).

    PubMed

    Niinuma, A

    1999-11-01

    The aim of this study was to evaluate a newly developed resin (MTYA1-Ca) for direct pulp capping. The powder of MTY1-Ca is composed of 89.0% microfiller, 10.0% calcium hydroxide and 1.0% benzoyl peroxide and was mixed with liquid (67.5% triethyleneglycol dimethacrylate, 30.0% glyceryl methacrylate, 1.0% o-methacryloyl tyrosine amide, 1.0% dimethylaminoethylmethacrylate, and 0.5% camphorquinone). The shear bond, diametral tensile, bending and compressive strengths were measured. The alkaline activity of the elute dissolved from MTYA1-Ca was calculated. Cell viability by MTT assay and alkaline phosphatase (ALPase) activity were evaluated from dental pulp fibroblast reaction to the eluate dissolved from MTYA1-Ca. Histopathological studies of the response to exposed dental pulp of beagle dogs were completed with Dycal as a control. The physical properties of MTYA1-Ca were significantly superior to those of Dycal. It was impossible to measure these properties with Dycal because of poor physical properties. Both MTYA1-Ca and Dycal maintained high levels of alkaline activity (pH 10.96-12.20) over the 168-h duration of the study. Cell viability by MTT assay in the intact eluate of MTYA1-Ca was significantly higher than that of Dycal, whilst ALPase showed no difference between MTYA1-Ca and Dycal. A dentine bridge formed more slowly under MTYA1-Ca than under Dycal, but similar amounts had formed at 90 days. MTYA1-Ca has the potential to be used as a direct pulp capping material.

  11. Mineral Trioxide Aggregate vs. Calcium Hydroxide in Primary Molar Pulpotomy: A Systematic Review

    PubMed Central

    Shirvani, Armin; Hassanizadeh, Raheleh; Asgary, Saeed

    2014-01-01

    Introduction: The aim of this quantitative systematic review/meta-analysis was to compare the treatment outcomes of mineral trioxide aggregate (MTA) and calcium hydroxide (CH) in pulpotomy of human primary molars. The focused PICO question was “in case of pulp exposure in vital primary molars, how does MTA pulpotomy compare to CH in terms of clinical/radiographic success?” Methods and Materials: We retrieved published randomized clinical trials (RCTs) of at least 6-month duration; our search included articles published up to March 2013 in five following databases: PubMed (Medline), Cochrane database of systematic reviews, Science Citation Index, EMBASE, and Google Scholar. Mantel Haenszel and Inverse Variance-weighted methods were applied by STATA; the relative risk (RR) was calculated with 95% confidence intervals (CI). Results: A total of 282 English articles were collected. Two authors independently screened the articles and five RCTs were selected; data extraction and quality assessment were then carried out. Four RCTs were appropriate for meta-analysis according to their follow-up times by Mantel Haenszel method. Statistically significant difference was found between success rate of MTA compared to CH, with RR=0.08 (95% CI, 0.02-0.39), RR=0.19 (95% CI, 0.08-0.46), and RR=0.38 (95% CI, 0.21-0.68) for 6-, 12-, and 24-month follow-ups, respectively. A significant difference was also observed for all included RCTs after analyses using the Inverse Variance-weighted method (RR=0.44; 95% CI, 0.27-0.72). Conclusions: Systematic review/meta-analysis of included RCTs revealed that for pulpotomy of vital primary molars, MTA has better treatment outcomes compared to CH. PMID:24688575

  12. Evaluation of calcium (Ca2+) and hydroxide (OH-) ion diffusion rates of indirect pulp capping materials.

    PubMed

    Kurun Aksoy, Merve; Tulga Oz, Firdevs; Orhan, Kaan

    2017-07-08

    The aim of this study was to evaluate and compare the calcium (Ca2+) and hydroxide (OH-) ion release of 4 artificially produced pulp capping materials (MTA, Biodentin, TheraCal LC, Calsimol) used for indirect pulp capping treatment. In total, 70 freshly extracted human third molar teeth were used for the study. Cavities of extracted teeth were prepared by round burs. The remaining dentin thickness (1 ± 0.3 mm) tissue was measured by a micrometer and cone beam computerized tomography. Indirect pulp capping was performed in the cavities using Calcimol, MTA, TheraCal LC and Biodentin. The leached Ca2+ were measured using optical emission spectrometry and the release of OH- ions using a pH meter. The measurements were performed after 24 hours, 7 days and 28 days in saline solution. Statistical analysis was performed using 1-way and 2-way analysis of variance (ANOVA) tests (p<0.05). Ca2+ ions were detected in treated saline solution during the experimental period for all materials. All the measurements of Biodentin and Theracal LC levels for Ca2+ ions were higher than those of the other materials (p<0.05). For all materials, Ca2+-ion release increased during the first 7 days followed by a linear decrease during the subsequent study periods. The Biodentine group showed the highest OH- ion rates compared to the other materials in the 24-hour examination period, while the scores gradually decreased during the subsequent measurement periods (p<0.05). Tricalcium silicate materials such as Biodentine and TheraCal LC used in this study may be preferable for indirect pulp capping because of their stimulation of hard tissue formation and ion-releasing ability.

  13. Sealing ability of composite resin placed over calcium hydroxide and calcium sulphate plugs in the repair of furcation perforations in mandibular molars: a study in vitro.

    PubMed

    Imura, N; Otani, S M; Hata, G; Toda, T; Zuolo, M L

    1998-03-01

    The purpose of this study was to evaluate in vitro the sealing ability of various materials in the repair of furcation perforations in mandibular molars by measuring coronal microleakage with Indian ink. Ninety extracted mandibular molars were embedded individually into a plaster of Paris block, with the roots surrounded by a simulated periodontal ligament of silicone. Subsequently, a standard coronal access opening was prepared, the root canal orifices were located and a perforation was made with a size 012 round bur in a water-cooled high-speed handpiece directly into the centre of the floor of the pulp chamber. The perforations were repaired with amalgam, composite resin, calcium sulphate under composite resin and calcium hydroxide under composite resin. The teeth were coated with two layers of nail polish, leaving the access opening area uncovered, and immersed in Indian ink for 4 days at 37 degrees C. The teeth were sectioned longitudinally and dye penetration measured from the coronal level of the repair material to the apical end of the perforation. All experimental groups revealed dye penetration in varying degrees, but there was no significant difference amongst them (Kruskal-Wallis test P < 0.05). Calcium sulphate and calcium hydroxide prevented overextrusion of composite resin when used under this repair material.

  14. Chlorhexidine, ethanol, lipopolysaccharide and nicotine do not enhance the cytotoxicity of a calcium hydroxide pulp capping material.

    PubMed

    Wheater, M A; Falvo, J; Ruiz, F; Byars, M

    2012-11-01

    To determine whether cells pre-stressed by known cytotoxic or inflammatory agents are more susceptible to the deleterious effects of a calcium hydroxide formulation used in pulp capping. Adult human dermal fibroblasts were treated for 48 h with 0.001% chlorhexidine, 0.2% ethanol, 5 μg mL(-1) Escherichia coli lipopolysaccharide (LPS) or 0.05 mmol L(-1) nicotine. Cells were subsequently treated with the soluble materials extracted from Dycal pellets for an additional 24 h. Controls included cells cultured in medium only and cells exposed to Dycal only. Cytotoxicity was measured using colorimetric MTT, WST and secreted lactate dehydrogenase assays. In addition, mitotic activity was evaluated using a colorimetric histone H3 phosphorylation assay. Data were statistically analysed using anova with Tukey's multiple comparison post-test and significance at P ≤ 0.05. For all assays, measured values for cells treated with chlorhexidine, ethanol, LPS or nicotine plus the soluble materials extracted from Dycal pellets were significantly lower compared to control (P < 0.05) for all comparisons between experimental conditions. However, between treatments and for comparisons of treatments with Dycal, there were no differences observed for any assay. Calcium hydroxide in a formulation used in dental clinical procedures is highly cytotoxic to cultured cells, as evidenced by several cellular assays. However, other known toxic agents, including chlorhexidine, ethanol, bacterial LPS and nicotine, do not appear to function synergistically to increase the deleterious cellular effects of the calcium hydroxide in an in vitro model of cytotoxicity. © 2012 International Endodontic Journal.

  15. Effect of different adhesive protocols vs calcium hydroxide on primary tooth pulp with different remaining dentin thicknesses:24-month results.

    PubMed

    Büyükgüral, Bülent; Cehreli, Zafer C

    2008-03-01

    The aim of this randomized, controlled, single-blind and prospective study was to evaluate the clinical and radiographic success rates of three different bonding protocols vs calcium hydroxide liner for protection of the dentin-pulp complex of primary molars with different remaining dentin thicknesses. Two hundred forty primary molar teeth with moderate to deep occlusal caries were restored in 97 children who met inclusion criteria. After cavity preparation, the teeth were randomly assigned into four groups (n = 60/group) with respect to the material used for protection of the dentin-pulp complex: (1) total-etching with 36% phosphoric acid followed by an acetone-based adhesive (Prime&Bond NT), (2) a self-etch adhesive system (Xeno III), (3) an acetone-based adhesive (Prime&Bond NT) without prior acid conditioning, and (4) control: calcium hydroxide cement (Dycal). Teeth in groups 1-3 were restored with a polyacid-modified resin-based composite (Dyract AP) and those in group 4 with amalgam. The remaining dentin thickness was calculated using image analysis software (ImageJ). The teeth were evaluated clinically and radiographically for 24 months. The distribution of restored teeth with minimal remaining dentin thickness (< or =0.5 mm) was 3.3, 8.3, 8.3, and 10% for groups 1, 2, 3, and 4, respectively. Despite the absence of pulpal protection in groups 1-3, none of those teeth exhibited any significant clinical or radiographic symptom during the study period. After 2 years, the clinical and radiographic success rate of restorative treatments was 100%. Protection of the dentin-pulp complex with the tested bonding protocols resulted in similar outcomes in mainly shallow and medium deep cavities as compared to calcium hydroxide amalgam in more deep cavities, when indirect pulp treatment was performed in class I compomer restorations.

  16. Antioxidant and cytoprotective activities of Piper betle, Areca catechu, Uncaria gambir and betel quid with and without calcium hydroxide

    PubMed Central

    2013-01-01

    Background Betel quid chewing is a popular habit in Southeast Asia. It is believed that chewing betel quid could reduce stress, strengthen teeth and maintain oral hygiene. The aim of this study was to investigate the antioxidant and cytoprotective activities of each of the ingredients of betel quid and compared with betel quid itself (with and without calcium hydroxide). The correlation of their cytoprotective and antioxidant activities with phenolic content was also determined. Methods Five samples (betel leaf, areca nut, gambir, betel quid and betel quid containing calcium hydroxide) were extracted in deionized distilled water for 12 hours at 37°C. Antioxidant activities were evaluated for radical scavenging activity using DPPH assay, ferric reducing activity using FRAP assay and lipid peroxidation inhibition activity using FTC assay. Total phenolic content (TPC) was determined using Folin-Ciocalteu procedure. Phenolic composition was analyzed using LC-MS/MS. Cytoprotective activity towards human gingival fibroblast cells was examined using MTT assay. Results Among the ingredients of betel quid, gambir demonstrated the highest antioxidant (DPPH - IC50 = 6.4 ± 0.8 μg/mL, FRAP - 5717.8 ± 537.6 μmol Fe(II)/mg), total phenolic content (TPC - 1142.5 ± 106.8 μg TAE/mg) and cytoprotective (100.1 ± 4.6%) activities. Betel quid when compared with betel quid containing calcium hydroxide has higher antioxidant (DPPH - IC50 =59.4 ± 4.4 μg/mL, FRAP - 1022.2 ± 235.7 μmol Fe(II)/mg), total phenolic content (TPC - 140.0 ± 22.3 μg TAE/mg), and cytoprotective (113.5 ± 15.9%) activities. However, all of the five samples showed good lipid peroxidation inhibition compared to vitamin E. LC-MS/MS analysis revealed the presence of quinic acid as the major compound of gambir and betel quid. A positive correlation was observed between TPC and radical scavenging (r = 0.972), reducing power (r = 0.981) and cytoprotective

  17. The Efficacy of Calcium Hydroxide Powder mixed with 0.2% Chlorhexidine Digluconate or mixed with Normal Saline as Intracanal Medicament in the Treatment of Apical Periodontitis.

    PubMed

    Menakaya, Ifeoma N; Adegbulugbe, Ilemobade C; Oderinu, Olabisi H; Shaba, Olufemi P

    2015-08-01

    To compare the efficacy of calcium hydroxide powder mixed with 0.2% chlorhexidine digluconate or mixed with normal saline as intracanal medicament in the treatment of apical periodontitis. Subjects were 55 in number aged 17 to 60 years. Two-visit conventional root canal treatment was performed on 70 teeth. The teeth were divided by randomization (balloting) into two groups: control group and experimental group, each with 35 teeth treated with calcium hydroxide mixed with normal saline or with 0.2% chlorhexidine digluconate as intracanal medicament respectively. All treated teeth were evaluated clinically and radiographically for signs and symptom of periapical infection at specified periods postoperatively. Overall efficacy of medicament was rated based on quality guidelines for endodontic treatment by the European Society of Endodontology 2006. A postoperative favorable outcome of 97.1% in the control group and 94.3% in the experimental group was observed at 6-month review. This difference was not statistically significant (p > 0.05). The use of normal saline or 0.2% chlorhexidine digluconate to mix calcium hydroxide used as intracanal medicament during endodontic treatment resulted in high postoperative favorable outcomes. Efficacy of 0.2% chlorhexidine digluconate as a vehicle for mixing calcium hydroxide as an intracanal medicament in the treatment of apical periodontitis is comparable to the efficacy of calcium hydroxide mixed with normal saline.

  18. Fracture resistance of immature teeth filled with BioAggregate, mineral trioxide aggregate and calcium hydroxide.

    PubMed

    Tuna, Elif Bahar; Dinçol, Muzaffer Emir; Gençay, Koray; Aktören, Oya

    2011-06-01

    Abstract -  Background: The aim of this in vitro study was to assess the long-term fracture resistance of human immature permanent teeth filled with BioAggregate (BA), mineral trioxide aggregate (MTA) and calcium hydroxide (CH).  The study consisted of single rooted premolar teeth with immature root formation extracted for orthodontic reasons. A total of 28 immature premolars with average root length of 10.7 mm and apical diameter of 3 mm were included in the study. The pulps were extirpated and the canals were prepared using an apical approach. The teeth were randomly assigned to four groups: Group I: DiaRoot(®) BA (DiaDent, Burnaby, BC, Canada), Group II: Angelus MTA (MTA-A; Angelus, Londrina, Brazil), Group III: ProRoot(®) MTA (MTA-PR; Dentsply, Tulsa, OK, USA), Group IV: CH (Sultan Chemists Inc., Englewood, NJ, USA). The teeth were placed in saline solution at 4°C for 1 year. The root of each tooth was then embedded in an acrylic resin block. All specimens were loaded at a crosshead speed of 1 mm min(-1) in an Instron testing machine and the peak loads up to fracture were recorded. Data were analysed statistically by Kruskal-Wallis and Mann-Whitney U-tests.  Mean (±SD) failure loads (MPa) were: 37.69 ± 14.43 for BA group, 32.94 ± 8.15 for MTA-A group, 28.74 ± 9.49 for MTA-PR group and 23.18 ± 8.48 for CH group. The BA group exhibited the highest fracture resistance and the CH group showed the lowest resistance to fracture. Significant differences (P < 0.05) in fracture resistance were found between the DiaRoot-BA and CH groups, and also between the MTA-A and CH groups.  Within the limitations of this study, data suggest that DiaRoot-BA-filled immature teeth demonstrate higher fracture resistance than other groups at 1 year. Considering the long-term risk of cervical root fracture associated with immature teeth, the use of DiaRoot-BA as a root canal filling material appears to be the most advantageous of the

  19. The effect of calcium hydroxide on solubilisation of bio-active dentine matrix components.

    PubMed

    Graham, Lee; Cooper, Paul R; Cassidy, Nicola; Nor, Jacques E; Sloan, Alastair J; Smith, Anthony J

    2006-05-01

    Calcium hydroxide (Ca(OH)(2)) has been used extensively to induce dentine regeneration through formation of dentine bridges at sites of pulp exposure after dental tissue injury, however, the biological processes underpinning these events are unclear. We hypothesise that growth factors and other bio-active molecules, sequestered within dentine matrix, may be released by the action of Ca(OH)(2) and signal gene expression in pulp cells, which mediates the changes in cell behaviour observed during regeneration. Powdered sound, human dentine samples were extracted with either 0.02 m Ca(OH)(2), pH 11.7 or 10% EDTA, pH 7.2 ( a control known extractant of bio-active and other ECM molecules from dentine) over a 14-day period. Extracts were compared for non-collagenous protein (NCP) and glycosaminoglycan (GAG) content using dye binding assays and protein compositions were analysed by 1D-polyacrylamide gel electrophoresis (1D-PAGE) and TGF-beta1 ELISA. The effects of extracts on TGF-beta1, Collagen-1alpha and Nestin gene expression were analysed using semi-quantitative RT-PCR in the dental MDPC-23, OD-21 and fibroblastic Swiss 3T3 cell lines following 24h of exposure. Ca(OH)(2) solubilised NCPs and GAGs from the dentine ECM, although with a lower yield than the EDTA solution and with different kinetics. 1D-PAGE analysis demonstrated some differences in profiles for proteins solubilised from dentine by Ca(OH)(2) and EDTA. Both solutions released TGF-beta1 from the dentine with higher concentrations present in the EDTA (1.395 +/- 0.036 ng/mg) versus the Ca(OH)(2) (0.364 +/- 0.012 ng/mg) extract. Notably, both extracts induced similar gene expression profiles in all cell lines. These data provide a rational explanation for the action of Ca(OH)(2) during pulp capping in which the cellular activities involved in dentine bridge formation may be mediated through release of growth factors and other bio-active molecules from the dentine by Ca(OH)(2).

  20. Effects of chemomechanical preparation with 2.5% sodium hypochlorite and intracanal medication with calcium hydroxide on cultivable bacteria in infected root canals.

    PubMed

    Siqueira, José F; Guimarães-Pinto, Tatiana; Rôças, Isabela N

    2007-07-01

    This clinical study was conducted to assess the bacterial reduction after chemomechanical preparation with 2.5% NaOCl as an irrigant and the additive antibacterial effect of intracanal dressing with calcium hydroxide. According to stringent inclusion criteria, 11 teeth with primary intraradicular infections and chronic apical periodontitis were selected and monitored in the study. Bacterial samples were taken at the baseline (before treatment) (S1), after chemomechanical preparation with 2.5% NaOCl as an irrigant (S2), and after a 7-day dressing with a calcium hydroxide paste in glycerin (S3). Cultivable bacteria recovered from infected root canals at the 3 stages were counted and identified by means of 16S rRNA gene sequencing analysis. At S1, all canals were positive for bacteria, with the mean number of 2.8 taxa per canal (range, 1-6). At S2, 5 cases (45.5%) still harbored cultivable bacteria, with 1 or 2 species per canal. At S3, bacteria were cultured from 2 cases (18.2%), with 1 species per positive case. There was no indication that any specific bacterial taxon was more resistant to treatment. A significant reduction in bacterial counts was observed between S1 and S2, and S1 and S3. However, no statistically significant difference was observed for comparisons involving S2 and S3 samples with regard to the number of cases yielding negative cultures (P = .18) or quantitative bacterial reduction (P = .19). It was concluded that the whole antibacterial protocol used in this study significantly reduced the number of bacteria in the canal and rendered most canals free of cultivable bacteria.

  1. Revascularization of an Immature Tooth with Apical Periodontitis Using Calcium Hydroxide: A 3-year Follow-up.

    PubMed

    Silva, Mauro Henrique Chagas; Campos, Celso Neiva; Coelho, Marcelo Santos

    2015-01-01

    Root canal treatment of teeth presenting immature development is a great challenge for both the patient and the professional. The thinness of the root canal walls of immature teeth may lead to root fracture and thus the outcomes of such treatments are uncertain. Revascularization is based on root canal decontamination followed by the induction of blood migration from the periapical tissues and the development of new vascular tissue in the canal space. The principle of disinfection in regenerative endodontics is that it should be achieved with minimum root canal instrumentation; an intracanal medication is used to inhibit bacterial growth and appropriate sealing of the coronal portion is performed. The American Association of Endodontists (AAE) considerations for regenerative endodontics include calcium hydroxide as an alternative intracanal dressing. This material has also been claimed to diminish the possibility of dental staining during revascularization procedures. The relatively new treatment protocol has been widely reported in the last few years; however it should be performed only when other alternatives are not reasonable. This case report presents a 3-year follow-up of a case of revascularization of a maxillary central incisor using calcium hydroxide as a root canal disinfection dressing.

  2. The effect of sodium hypochlorite application on the success of calcium hydroxide and mineral trioxide aggregate pulpotomies in primary teeth.

    PubMed

    Akcay, Merve; Sari, Saziye

    2014-01-01

    This study's purpose was to evaluate the success of calcium hydroxide (CH) and mineral trioxide aggregate (MTA) pulpotomies following the use of five percent sodium hypochlorite (NaOCl) as an antibacterial agent to clean the chamber prior to application of the pulpotomy agent. A total of 128 teeth were randomly divided into two pulpotomy groups (CH or MTA). The teeth in each pulpotomy group, CH and MTA, were further randomly divided into subgroups to receive either the NaOCl (experimental) or saline (control) cleaning agent prior to applying the pulpotomy agent. The treatments were followed clinically and radiographically for 12 months. The radiographic success rates were 84 percent for CH NaOCl, 74 percent for CH saline control, 97 percent for MTA NaOCl, and 100 percent for MTA saline control. There were no significant differences between the radiographic success rates in the CH and MTA subgroups (CH NaOCl-CH control and MTA NaOCl-MTA control); no significant differences were observed when comparing the CH NaOCl-MTA NaOCl groups and the CH NaOCl-MTA control groups. Use of sodium hypochlorite as an antibacterial agent prior to application of the pulpotomy agent improved the success of calcium hydroxide pulpotomies to equal the success of mineral trioxide aggregate pulpotomies for observation up to 12 months.

  3. Revascularization of an Immature Tooth with Apical Periodontitis Using Calcium Hydroxide: A 3-year Follow-up

    PubMed Central

    Silva, Mauro Henrique Chagas; Campos, Celso Neiva; Coelho, Marcelo Santos

    2015-01-01

    Root canal treatment of teeth presenting immature development is a great challenge for both the patient and the professional. The thinness of the root canal walls of immature teeth may lead to root fracture and thus the outcomes of such treatments are uncertain. Revascularization is based on root canal decontamination followed by the induction of blood migration from the periapical tissues and the development of new vascular tissue in the canal space. The principle of disinfection in regenerative endodontics is that it should be achieved with minimum root canal instrumentation; an intracanal medication is used to inhibit bacterial growth and appropriate sealing of the coronal portion is performed. The American Association of Endodontists (AAE) considerations for regenerative endodontics include calcium hydroxide as an alternative intracanal dressing. This material has also been claimed to diminish the possibility of dental staining during revascularization procedures. The relatively new treatment protocol has been widely reported in the last few years; however it should be performed only when other alternatives are not reasonable. This case report presents a 3-year follow-up of a case of revascularization of a maxillary central incisor using calcium hydroxide as a root canal disinfection dressing. PMID:26962377

  4. Calcium hydroxide nanoparticles for the conservation of cultural heritage: new formulations for the deacidification of cellulose-based artifacts

    NASA Astrophysics Data System (ADS)

    Poggi, G.; Toccafondi, N.; Melita, L. N.; Knowles, J. C.; Bozec, L.; Giorgi, R.; Baglioni, P.

    2014-03-01

    Alkaline earth metal hydroxide nanoparticles dispersions have demonstrated to be efficient for the preservation of cellulose-based artifacts, providing a stable neutral environment and, if in excess, turning into mild alkaline species. New formulations tailored for specific conservation issues have been recently obtained via a solvothermal reaction, starting from bulk metal, and short chain alcohols. Using this synthetic procedure, stable, and high concentrated calcium hydroxide nanoparticles dispersions can be obtained. The characterization of nanoparticles was carried out by dynamic light scattering, transmission electron microscopy and X-ray powder diffraction and showed that the dispersed systems are particularly suitable for the application on porous substrates. In a direct application of this technology, acidic paper and canvas samples were artificially aged after deacidification using calcium hydroxide nanoparticles dispersed in short chain alcohols. Cellulose viscosimetric polymerization degree (DPv), cellulose pyrolysis temperature, and samples' pH were evaluated upon the aging and in terms of protective action arising from the applied treatment. In particular, determinations of DPv clearly showed that the degradation of acidic paper and canvas samples proceeds at higher rates with respect to deacidified samples. These evidences were also confirmed by the thermogravimetric analysis of samples, in which the benefits due to the deacidification treatments are measured in terms of pyrolysis temperature of cellulose. These new formulations of nanoparticles dispersions expand the palette of available tools for the conservation of cellulose-based works of art, such as easel paintings, and manuscripts, potentially opening the way for the intervention on parchment and leather, whose preservation is a particularly challenging task.

  5. [Efficacy of sodium hydroxide at 2.5 %, chlorhexidine gluconate at 0.5 % and calcium hydroxide against Candida albicans].

    PubMed

    Ndiaye, D; Diongue, K; Bane, K; Seck, A; Niang, S O; Lèye Benoist, F; Ndiaye, D; Touré, B

    2016-12-01

    Endodontic flora is dominated in the apical part of the channels by strict anaerobic and some facultative anaerobic bacteria but also by Candida yeasts, especially Candida albicans species that are involved in the maintenance and persistence of endodontic infections. Their elimination of the canal system in practice by chemo-mechanical methods of disinfection is not always guaranteed. Thus, this in vitro study was performed to determine the sensitivity of C. albicans with sodium hypochlorite (NaOCl) dosed at 2.5 %, the chlorhexidine digluconate 0.5 % and calcium hydroxide used in inter-session medication. The diffusion method was used initially to test the sensitivity of C. albicans strains with the above products. Then a dilution technique has allowed us to determine the minimum inhibitory concentration of these active products on C. albicans. Strains from infected pulp teeth of patients showed a sensitivity of C. albicans to sodium hypochlorite to a minimum inhibitory concentration less than 70μg/mL and 30μg/mL for chlorhexidine. This study demonstrated a sensitivity of C. albicans to sodium hypochlorite and chlorhexidine. Copyright © 2016. Published by Elsevier Masson SAS.

  6. Comparison of the adjuvant activity of aluminum hydroxide and calcium phosphate on the antibody response towards Bothrops asper snake venom.

    PubMed

    Olmedo, Hidekel; Herrera, María; Rojas, Leonardo; Villalta, Mauren; Vargas, Mariángela; Leiguez, Elbio; Teixeira, Catarina; Estrada, Ricardo; Gutiérrez, José María; León, Guillermo; Montero, Mavis L

    2014-01-01

    The adjuvanticity of aluminum hydroxide and calcium phosphate on the antibody response in mice towards the venom of the snake Bothrops asper was studied. It was found that, in vitro, most of the venom proteins are similarly adsorbed by both mineral salts, with the exception of some basic phospholipases A2, which are better adsorbed by calcium phosphate. After injection, the adjuvants promoted a slow release of the venom, as judged by the lack of acute toxicity when lethal doses of venom were administered to mice. Leukocyte recruitment induced by the venom was enhanced when it was adsorbed on both mineral salts; however, venom adsorbed on calcium phosphate induced a higher antibody response towards all tested HPLC fractions of the venom. On the other hand, co-precipitation of venom with calcium phosphate was the best strategy for increasing: (1) the capacity of the salt to couple venom proteins in vitro; (2) the venom ability to induce leukocyte recruitment; (3) phagocytosis by macrophages; and (4) a host antibody response. These findings suggest that the chemical nature is not the only one determining factor of the adjuvant activity of mineral salts.

  7. Ions Release and pH of Calcium Hydroxide-, Chlorhexidine- and Bioactive Glass-Based Endodontic Medicaments.

    PubMed

    Carvalho, Ceci Nunes; Freire, Laila Gonzales; Carvalho, Alexandre Pinheiro Lima de; Duarte, Marco Antonio Húngaro; Bauer, José; Gavini, Giulio

    2016-01-01

    This study evaluated pH and release of calcium, sodium and phosphate ions from different medications in human dentin. Fifty premolars were prepared and randomly divided into groups: (CHX) - 2% chlorhexidine gel; (CHX + CH) - CHX + calcium hydroxide PA; (CH) - CH + propylene glycol 600; (NPBG) - experimental niobium phosphate bioactive glass + distilled water; (BG) - bioactive glass (Bio-Gran) + distilled water. The specimens were immersed in deionized water and the pH variations were measured. The quantification of ions in the solutions was made by inductively coupled plasma - atomic emission spectroscopy (ICP/AES) at 10 min, 24 h, 7, 14, 21 and 30 days. The results were analyzed by ANOVA and Tukey`s test, with a significance level of 5%. CH had the highest level of calcium ions release at 30 days, while CHX and BG released more sodium ions. BG, NPBG and CHX released a higher amount of phosphate ions. The pH of CH was significantly higher compared with the other groups. CH favored the greatest increase of pH and calcium ions release. The bioactive glasses released more sodium and phosphate ions and presented an alkaline pH immediately and after 30 days.

  8. An investigation of the relative efficacy of Buckley's Formocresol and calcium hydroxide in primary molar vital pulp therapy.

    PubMed

    Waterhouse, P J; Nunn, J H; Whitworth, J M

    2000-01-08

    To compare the clinical and radiological outcomes following two different, single visit vital pulp therapy techniques, in cariously exposed primary molar teeth. A paediatric dental clinic within the Dental Hospital, Newcastle upon Tyne, UK. Fifty two child patients were sequentially enrolled in the clinical investigation, 26 males and 26 females with an age range of 3.3-12.5 years. Primary molar teeth requiring vital pulp therapy were randomly allocated to either the formocresol group (F) or the calcium hydroxide group (C). The total number of teeth treated was 84. Recruitment was on the basis of strict inclusion criteria. Coronal pulp amputation was prescribed only in teeth with vital, cariously exposed pulp tissue. Treatment was undertaken between October 1994 and December 1996. All cases were reviewed using predefined clinical and radiological criteria. The statistical tests used were logistic regression of a triple nested data structure, chi-squared analysis of equality of treatment and probability of success with relation to subject age. Eighty-four cariously exposed primary molars required vital pulp therapy. Forty six (55%) teeth were included in the F group and 38 (45%) allocated to the C group. Five teeth were lost to follow-up, leaving 79 teeth: forty four (56%) in group F and 35 (44%) in group C. Eighty four percent (37/44) of teeth treated with formocresol and 77 percent (27/35) treated with calcium hydroxide were classed as clinically and radiographically successful at the cut-off date, December 1997, after a mean clinical review of 22.5 months (range 6.1-38.5 months) and a mean radiographic review of 18.9 months (range 1.3-36.9 months). This investigation confirms the clinical efficacy of a one-fifth dilution of Buckley's Formocresol as an agent in pulp treatment of cariously exposed, vital primary molar teeth. However, calcium hydroxide in its pure, powder form is a clinically acceptable alternative when combined with strict selection criteria for

  9. Efficacy of XP-endo finisher and TRUShape 3D conforming file compared to conventional and ultrasonic irrigation in removing calcium hydroxide.

    PubMed

    Uygun, Ahmet Demirhan; Gündoğdu, Eyüp Candaş; Arslan, Hakan; Ersoy, İbrahim

    2016-11-12

    The aim of this study was to compare the efficacy of the XP-endo Finisher and TRUShape 3D Conforming File to conventional and ultrasonic irrigation techniques for removing calcium hydroxide from artificially created grooves on root canals. The study used 32 human mandibular premolar teeth, which were decoronated and instrumented up to ProTaper Universal F5 (Dentsply Maillefer; Ballagiues, Switzerland). The teeth were split longitudinally, two standardised grooves were prepared in the apical and coronal portions and filled with calcium hydroxide. Each tooth was reassembled with wax. The samples were stored at 100% humidity at 37°C for 1 week, after which the specimens were grouped and irrigated using needle irrigation, ultrasonic irrigation, XP-endo Finisher via continuous irrigation or TRUShape 3D Conforming File via continuous irrigation. Two calibrated observers scored the amount of calcium hydroxide remaining, and the data were statistically analysed using the Kruskal-Wallis and Mann-Whitney U-tests, (P < 0.05). Needle irrigation had the poorest scores (P < .001), while the XP-endo Finisher, TRUShape 3D Conforming File via continuous irrigation and ultrasonic irrigation groups had similar results in removing calcium hydroxide.

  10. Comparison of mineral trioxide aggregate and calcium hydroxide for apexification of immature permanent teeth: A systematic review and meta-analysis.

    PubMed

    Lin, Jia-Cheng; Lu, Jia-Xuan; Zeng, Qian; Zhao, Wei; Li, Wen-Qing; Ling, Jun-Qi

    2016-07-01

    Calcium hydroxide and mineral trioxide aggregate (MTA) are used for inducing a calcific barrier at an open tooth root (apexification). The purpose of this study was to compare the efficacy of calcium hydroxide and MTA for apexification of immature permanent teeth. Medline, Cochrane, EMBASE, and Google Scholar were searched until November 24, 2015, using the keywords apexification, permanent teeth, MTA, and calcium hydroxide. Of 216 studies identified, four studies were included. There were no differences in the clinical success rate [pooled odds ratio (OR) = 3.03, 95% confidence interval (CI): 0.42-21.72, p = 0.271], radiographic success rate (pooled OR = 4.30, 95% CI: 0.45-41.36, p = 0.206), or apical barrier formation rate (pooled OR = 1.71, 95% CI: 0.59-4.96, p = 0.322) between calcium hydroxide and MTA groups. The time required for apical barrier formation was significantly less in the MTA group (pooled difference in means = -3.58, 95% CI: from -4.91 to -2.25, p < 0.001). While both materials provide similar success rates, the shorter treatment time with MTA may translate into higher overall success rates because of better patient compliance. Copyright © 2016. Published by Elsevier B.V.

  11. THE COMPARISON OF SEVERAL STANDARD MATERIALS AND TECHNIQUES FOR THE WARREN-AVERBACH DETERMINATION OF MICRO-STRUCTURE CHARACTERISTICS OF CALCIUM HYDROXIDE SORBENT MATERIALS

    EPA Science Inventory

    The paper gives results of a comparison of several standard materials and techniques for the Warren-Averbach determination of microstructure characteristics of calcium hydroxide--Ca(OH)2--sorbent materials. The comparison is part of an investigation of the injection of dry Ca(OH)...

  12. THE COMPARISON OF SEVERAL STANDARD MATERIALS AND TECHNIQUES FOR THE WARREN-AVERBACH DETERMINATION OF MICRO-STRUCTURE CHARACTERISTICS OF CALCIUM HYDROXIDE SORBENT MATERIALS

    EPA Science Inventory

    The paper gives results of a comparison of several standard materials and techniques for the Warren-Averbach determination of microstructure characteristics of calcium hydroxide--Ca(OH)2--sorbent materials. The comparison is part of an investigation of the injection of dry Ca(OH)...

  13. Effects of amine, amine salt and amide on the behaviour of carbon dioxide absorption into calcium hydroxide suspension to precipitate calcium carbonate.

    PubMed

    Chuajiw, Wittaya; Nakano, Mitsuru; Takatori, Kazumasa; Kojima, Toshiya; Wakimoto, Yoshiki; Fukushima, Yoshiaki

    2013-12-01

    The amount of carbon dioxide (CO2) absorption and calcium ion (Ca2+) concentration besides the pH of aqueous solution were observed during the CO2 absorption to precipitate calcium carbonate (CaCO3) from calcium hydroxide (Ca(OH)2). A reaction rate-limiting effect of an amount of CO2 absorption without any organic additives in the early stage of the precipitation was observed, which was attributed to an interruption effect of bicarbonate ion (HCO3(-)) on the precipitation of CaCO3. The improvement for the reaction rate was achieved not only by amine additives but also by neutral additives such as epsilon-caprolactam or amine salt. When the hexamethylene diamine was dissolved in the solution, successive change of crystal forms of CaCO3 aragonite to calcite in aqueous suspensions, confirmed by Ca2+ concentration change and X-ray diffraction, was concluded that a local environment around the amine group in aqueous solution and an interaction of the diamine with precipitated CaCO3 particles were important factors for these reactions.

  14. Assessment of the Potential of CFC (Calcium hydroxide Flagyl Ciprofloxacin) for the Rapid Disinfection of Resilon and Gutta-Percha.

    PubMed

    Hamza, Mariam Omer Bin; Gufran, Khalid; Baroudi, Kusai

    2015-10-01

    Obturating materials exposed to the dental operating environment has been shown to be contaminated, making rapid chair side disinfection mandatory to ensure the sterility of the root canals. The purpose of this study was to investigate the effectiveness of CFC (combination of Calcium hydroxide, Flagyl and Ciprofloxacin) for the rapid disinfection of Gutta-percha and Resilon cones. Seventy new Gutta-percha and Resilon cones were randomly selected, contaminated with Enterococcus faecalis and divided into 4 group according to the irrigant used for disinfection {Group I: 5.25% Sodium Hypochlorite (NaOCl), Group II: MTAD, Group III: 2% Chlorhexidine (CHX), Group IV: CFC (a combination of Calcium hydroxide, Flagyl and Ciprofloxacin)}. All the samples were placed in a centrifuge tube with BHI broth after being washed with sterile water. The samples were then incubated for 7 days at 37(o)C. Samples were randomly plated on Mac Conkey agar plate and the colony count was recorded and the observations were drawn. A 5.25% NaOCl required 1 minute exposure for effective disinfection of all the samples. MTAD could eliminate E.faecalis from gutta-percha samples in 30 seconds whereas it required 1 minute of exposure for Resilon cones. Both 2% CHX and CFC could not disinfect the samples with 1 minute exposure and a minimum of 5 minute exposure was required. A 5.25% NaOCl and Biopure MTAD required less chair side time to disinfect all the samples effectively when compared with 2% CHX and CFC.

  15. Spectrophotometric analysis of crown discoloration following the use of silver nanoparticles combined with calcium hydroxide as intracanal medicament

    PubMed Central

    Elahy, Sadaf; Mahmoudi-Nahavandi, Alireza

    2017-01-01

    Background Optimal antibacterial efficacy of intracanal medicaments containing silver nanoparticles (Ag-NPs) has been well documented. However, concerns remain regarding the effect of Ag-NPs on tooth color. This study aimed to assess the effects of calcium hydroxide (CH) mixed with Ag-NPs as intracanal medicaments on tooth color. The effect of location of application of medicament on the degree of discoloration was evaluated as well. Material and Methods Fifty extracted single-rooted, single-canal human teeth with straight roots, no caries, no cracks or fractures were collected and accessed. After cleaning and shaping of the root canals, the teeth were randomly divided into two experimental groups (n=20) with CH and CH plus Ag-NPs as intracanal medicaments and a control group of saline (n=10). Experimental groups were randomly divided into two equal subgroups of A, where medicament was applied below the cemento enamel junction (CEJ) and B where the medicament was applied to the root canal and pulp chamber. Color change (ΔE) was assessed using a spectrophotometer in CIELAB system at five time points of beforemedicaments application (T0), immediately medicaments placement (T1), one week (T2), one month (T3) and three months (T4) after the application of medicaments. Data were analyzed using two-way and three-way ANOVA. Results Color change in Ag-NPs plus CH and CH groups was not significantly different at any time point (P=0.23). Increased exposure time in both groups did not increase the ΔE (P >0.05). Significant differences were noted in ΔE between subgroups A and B (P<0.05). Conclusions Addition of Ag-NPs to CH caused no significant change in tooth color compared to the application of CH alone. However, its use must be limited to the root canal space only. Key words:Silver nanoparticles, color change, calcium hydroxide, spectrophotometry, intracanal medicament. PMID:28828148

  16. Assessment of the Potential of CFC (Calcium hydroxide Flagyl Ciprofloxacin) for the Rapid Disinfection of Resilon and Gutta-Percha

    PubMed Central

    Hamza, Mariam Omer Bin; Gufran, Khalid

    2015-01-01

    Introduction Obturating materials exposed to the dental operating environment has been shown to be contaminated, making rapid chair side disinfection mandatory to ensure the sterility of the root canals. Objective The purpose of this study was to investigate the effectiveness of CFC (combination of Calcium hydroxide, Flagyl and Ciprofloxacin) for the rapid disinfection of Gutta-percha and Resilon cones. Materials and Methods Seventy new Gutta-percha and Resilon cones were randomly selected, contaminated with Enterococcus faecalis and divided into 4 group according to the irrigant used for disinfection {Group I: 5.25% Sodium Hypochlorite (NaOCl), Group II: MTAD, Group III: 2% Chlorhexidine (CHX), Group IV: CFC (a combination of Calcium hydroxide, Flagyl and Ciprofloxacin)}. All the samples were placed in a centrifuge tube with BHI broth after being washed with sterile water. The samples were then incubated for 7 days at 37oC. Samples were randomly plated on Mac Conkey agar plate and the colony count was recorded and the observations were drawn. Results A 5.25% NaOCl required 1 minute exposure for effective disinfection of all the samples. MTAD could eliminate E.faecalis from gutta-percha samples in 30 seconds whereas it required 1 minute of exposure for Resilon cones. Both 2% CHX and CFC could not disinfect the samples with 1 minute exposure and a minimum of 5 minute exposure was required. Conclusion A 5.25% NaOCl and Biopure MTAD required less chair side time to disinfect all the samples effectively when compared with 2% CHX and CFC. PMID:26557614

  17. A novel model for testing the efficiency of removal of calcium hydroxide from complex root canal anatomies.

    PubMed

    Küçükkaya Eren, Selen; Aksel, Hacer; Parashos, Peter

    2017-04-01

    The purpose of this study was to evaluate the efficacy of several irrigation protocols in the removal of calcium hydroxide [Ca(OH)2 ] from simulated internal root resorption cavities in a complex root canal anatomy model. The 20° to 35° curved mesiobuccal roots of 94 maxillary molars were sectioned longitudinally; internal resorption cavities were prepared in the apical third of the canal walls. Calcium hydroxide was placed into the cavities and the root halves reassembled. Four teeth were used as controls, and 90 teeth were randomly divided into six experimental groups (n = 15), according to the irrigation protocols used: syringe irrigation; H2 O2 (HP); Navitip FX; Vibringe-syringe; Vibringe-NaviTip FX; ultrasonically activated irrigation (UAI) using an ultrasonic K-file. In the HP group, 2.5% NaOCl and 3% H2 O2 were used, while 2.5% NaOCl and 17% EDTA were used in the remaining groups. Stereomicroscope images and radiographs were used to measure the remaining Ca(OH)2 . The model proved to be suitable for simulating complex anatomy. Positive correlation was found between stereomicroscope and radiographic analyses (P < 0.05). UAI removed significantly more Ca(OH)2 than the other experimental groups (P < 0.05). The HP group was the least efficient protocol (P < 0.05). It would appear that a reliable model has been developed that simulates complex root canal anatomy. Irrigant activation protocols enhanced Ca(OH)2 removal. © 2017 Australian Society of Endodontology Inc.

  18. Calcium carbonate as a phosphate binder in dialysis patients: evaluation of an enteric-coated preparation and effect of additional aluminium hydroxide on hyperaluminaemia.

    PubMed

    Ittel, T H; Schäfer, C; Schmitt, H; Gladziwa, U; Sieberth, H G

    1991-01-22

    Calcium carbonate has been successfully used as a phosphate binder in patients with chronic renal failure; however, a high frequency of hypercalcaemia has been reported. To study the effects of calcium carbonate preparations with different dissolution characteristics on the incidence of this side effect, we conducted a double-blind, crossover trial in 21 patients undergoing chronic haemodialysis. Aluminum hydroxide therapy was replaced with calcium carbonate. The subjects then randomly received either an enteric-coated or a gastric-coated preparation. Calcium carbonate (3.1-3.6 g/d) controlled serum phosphate concentrations as effectively as aluminium hydroxide (2.9 g/d). Concurrently, there was a significant rise in mean serum calcium and a fall in serum concentrations of both parathyroid hormone and osteocalcin, the latter suggesting a decrease in bone turnover. Overall, hypercalcaemic episodes developed in 9 patients (43%) and occurred at a considerable frequency (33 episodes per 100 patient-months) during treatment with the gastric-coated formulation. Following conversion to enteric-coated calcium carbonate (3.6 g/d) patients had fewer occurrences of hypercalcaemia (12 episodes per 100 patient-months, P less than 0.05) and, as compared to the gastric-coated preparation, increases in serum calcium greater than 3.00 mmol/l were not observed at all. Hyperaluminaemia was regressive during therapy with calcium carbonate, but addition of small doses of aluminium hydroxide caused a large rise in serum aluminium concentrations after infusion of desferrioxamine, indicating an enhanced rate of absorption or aberrant compartmentalization of aluminium. We conclude that calcium carbonate can control hyperphosphataemia in dialysis patients.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Effect of cetyl trimethyl ammonium bromide concentration on structure, morphology and carbon dioxide adsorption capacity of calcium hydroxide based sorbents

    NASA Astrophysics Data System (ADS)

    Hlaing, Nwe Ni; Vignesh, K.; Sreekantan, Srimala; Pung, Swee-Yong; Hinode, Hirofumi; Kurniawan, Winarto; Othman, Radzali; Thant, Aye Aye; Mohamed, Abdul Rahman; Salim, Chris

    2016-02-01

    Calcium hydroxide (Ca(OH)2) has been proposed as an important material for industrial, architectural, and environmental applications. In this study, calcium acetate was used as a precursor and cetyl trimethyl ammonium bromide (CTAB) was used as a surfactant to synthesize Ca(OH)2 based adsorbents for carbon dioxide (CO2) capture. The effect of CTAB concentration (0.2-0.8 M) on the structure, morphology and CO2 adsorption performance of Ca(OH)2 was studied in detail. The synthesized samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), BET surfaced area and thermogravimetry-differential thermal analysis (TG-DTA) techniques. The phase purity, crystallite size, Brunauer-Emmett-Teller (BET) surface area and CO2 adsorption performance of Ca(OH)2 precursor adsorbents were significantly increased when the concentration of CTAB was increased. XRD results showed that pure Ca(OH)2 phase was obtained at the CTAB concentration of 0.8 M. TGA results exhibited that 0.8 M of CTAB-assisted Ca(OH)2 precursor adsorbent possessed a residual carbonation conversion of ∼56% after 10 cycles.

  20. Effect of Calcium Hydroxide on the Push-out Bond Strength of Endodontic Biomaterials in Simulated Furcation Perforations

    PubMed Central

    Ghasemi, Negin; Reyhani, Mohammad Forough; Salem Milani, Amin; Mokhtari, Hadi; Khoshmanzar, Faezeh

    2016-01-01

    Introduction: The aim of this in vitro study was to evaluate the effect of calcium hydroxide (CH) on push-out bond strength of white mineral trioxide aggregate (WMTA) and calcium-enriched mixture (CEM) cement in simulated furcation perforations. Methods and Materials: Furcation perforations, measuring 1.3 mm in diameter and 2 mm in height, were created in 80 human mandibular first molars. The teeth were then divided into 4 groups (n=20). In groups 1 and 3 CH was placed in the perforation for one week, before placement of WMTA and CEM. In groups 2 and 4 perforations were repaired without placement of CH. In groups 1 and 2 the perforation sites were repaired with WMTA and CEM cement was used in groups 3 and 4. After 7 days, the push-out test was carried out using a universal testing machine. Data were analyzed with two-way ANOVA. The level of significance was set at 0.05. Results: The maximum and minimum bond strength values were recorded in the WMTA/CH (13.08±1.8 MPa) and CEM cement groups (8.03±0.98 MPa), respectively. There were significant differences in resistance to dislodgement between the WMTA/CH and other groups (P<0.05). Conclusion: Placement of CH before placement of WMTA in furcation perforation improves the push-out bond strength of this material. PMID:27141214

  1. Laboratory Synthesized Calcium Oxide and Calcium Hydroxide Grains: A Candidate to Explain the 6.8 Micron Band

    NASA Technical Reports Server (NTRS)

    Kimura, Yuki; Nuth, Joseph A., III

    2005-01-01

    We will demonstrate that CaO and Ca(OH)2 are excellent candidates to explain the 6.8 microns feature, which is one of the most obscure features in young stellar objects. We discuss the condensation of CaO grains and the potential formation of a Ca(OH)2 surface layer. The infrared spectra of these grains are compared with the spectra of fifteen young stellar objects. We note that CaO-rich grains are seen in all meteoritic CAIs (calcium-aluminum-rich inclusions) and the 6.8 micron feature has only been observed in young stellar objects. Therefore, we consider CaO grains to be a plausible candidate to explain the 6.8 microns feature and hypothesize that they are produced in the hot interiors of young stellar environments.

  2. Investigation of early growth of calcium hydroxide crystals in cement solution by soft x-ray transmission microscopy

    SciTech Connect

    Harutyunyan, V. S.; Kirchheim, A. P.; Monteiro, P. J. M.; Aivazyan, A. P.; Fischer, P.

    2009-02-02

    Research on cement hydration was performed at the full-field soft transmission X-ray microscope XM-1 located at beamline 6.1.2 at the Advanced Light Source (ALS) in Berkeley CA which is operated by the Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, California. A series of works [1-3] has been conducted using this microscope for the in situ observation and qualitative analysis of through-solution hydration products and products of topochemical reactions, which form in cementitious aqueous solutions. This paper studies the precipitation of the calcium hydroxide (CH) crystals from the cement solution. The analysis of successive images of the hydration process provides critical quantitative information about the growth rate of calcium hydroxide (CH) crystals, the supersaturation ratio, and the kinetic and diffusion coefficients of the growth process. ASTM Type II portland cement and 6% C{sub 4}A{sub 3}{bar S} admixture were mixed in aqueous solution and saturated with respect to CH and gypsum. The C{sub 4}A{sub 3}{bar S} admixture was included in the experimental program because of the general research program on expansive cements, and adding C{sub 4}A{sub 3}{bar S} to portland cement is an efficient method of generating ettringite and significant early-age expansion. The solution/solid materials ratio was 10 cm{sup 3}/g, which is higher than the one existing in regular concrete and mortars; to compensate for this dilution, the solution was originally saturated with CH and gypsum. To allow sufficient transmission of the soft X-rays, a small droplet was taken from the supernatant solution and assembled in the sample holder, and then squeezed between two silicon nitride windows for the analysis. The X-ray optical setup of the microscope XM-1 is described elsewhere [2]. In this experiment, a wavelength of 2.4 nm (516.6 eV) was used. The radiation transmitting the sample was detected using an X-ray CCD camera, with a resolution of 35 nm provided

  3. A dynamic marine calcium cycle during the past 28 million years

    USGS Publications Warehouse

    Griffith, E.M.; Paytan, A.; Caldeira, K.; Bullen, T.D.; Thomas, E.

    2008-01-01

    Multiple lines of evidence have shown that the isotopic composition and concentration of calcium in seawater have changed over the past 28 million years. A high-resolution, continuous seawater calcium isotope ratio curve from marine (pelagic) barite reveals distinct features in the evolution of the seawater calcium isotopic ratio suggesting changes in seawater calcium concentrations. The most pronounced increase in the ??44/40Ca value of seawater (of 0.3 per mil) occurred over roughly 4 million years following a period of low values around 13 million years ago. The major change in marine calcium corresponds to a climatic transition and global change in the carbon cycle and suggests a reorganization of the global biogeochemical system.

  4. Coronary artery calcium scanning: past, present, and future.

    PubMed

    Hecht, Harvey S

    2015-05-01

    Coronary artery calcium scanning (CAC) has emerged as the most robust predictor of coronary events in the asymptomatic primary prevention population, particularly in the intermediate-risk cohort. Every study has demonstrated its superiority to risk factor-based paradigms, e.g., the Framingham Risk Score, with outcome-based net reclassification indexes ranging from 52.0% to 65.6% in the intermediate-risk, 34.0% to 35.8% in the high-risk, and 11.6% to 15.0% in the low-risk cohorts. CAC improves medication and lifestyle adherence and is cost-effective in specified populations, with the ability to effectively stratify the number needed to treat and scan for different therapeutic strategies and patient cohorts. Data have emerged clearly demonstrating the worse prognosis associated with increasing CAC on serial scans, suggesting a potential role for evaluating residual risk and treatment success or failure. CAC is also strongly associated with the development of stroke and congestive heart failure. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  5. Preparation of calcium- and magnesium-fortified potato starches with altered pasting properties.

    PubMed

    Noda, Takahiro; Takigawa, Shigenobu; Matsuura-Endo, Chie; Ishiguro, Koji; Nagasawa, Koichi; Jinno, Masahiro

    2014-09-15

    Calcium- and magnesium-fortified potato starches were prepared by immersion in various concentrations of CaCl2 and MgCl2 aqueous solutions, respectively. The pasting properties, i.e., peak viscosity and breakdown, of all the starches obtained above were analyzed using a Rapid Visco Analyzer. Furthermore, the gelatinization properties and in vitro digestibility of the representative calcium- and magnesium-fortified starches were tested. The maximum calcium content of the fortified potato starches was as high as 686 ppm with the addition of a high-concentration CaCl2 solution, while the calcium content of the control potato starch was 99 ppm. The magnesium content increased from 89 to 421 ppm by treatment of the potato starch with an MgCl2 solution. Markedly lower values of peak viscosity and breakdown were observed in calcium- and magnesium-fortified potato starches than in the control potato starch. However, the gelatinization temperature and enthalpy as well as resistant starch content of calcium- and magnesium-fortified potato starches were similar to those of the control potato starch. It is concluded that potato starches with altered pasting properties can be easily manufactured by the use of solutions containing high levels of calcium and magnesium.

  6. Early age hydration of calcium sulfoaluminate (synthetic ye'elimite, C{sub 4}A{sub 3}S{sup ¯}) in the presence of gypsum and varying amounts of calcium hydroxide

    SciTech Connect

    Hargis, Craig W.; Kirchheim, Ana Paula; Monteiro, Paulo J.M.; Gartner, Ellis M.

    2013-06-15

    Suspensions of synthetic ye'elimite (C{sub 4}A{sub 3}S{sup ¯}) in a saturated gypsum (CS{sup ¯}H{sub 2}) and calcium hydroxide (CH) solution were examined in-situ in a wet cell by soft X-ray transmission microscopy and ex-situ by scanning electron microscopy. The most voluminous hydration product observed was ettringite. Ettringite commonly displayed acicular, filiform, reticulated, and stellate crystal habits. Additionally, pastes with C{sub 4}A{sub 3}S{sup ¯}, 15% CS{sup ¯}H{sub 2}, and varying amounts of CH were prepared and examined with X-ray diffraction (XRD) and isothermal calorimetry. The XRD experiments showed that increasing CH content caused more solid solution (SO{sub 4}{sup 2−}/OH{sup −}) AFm phases to form at early ages (< 1 d) and more monosulfate to form at later ages (> 1 d). Calorimetry indicated that the increased production of solid solution AFm was accompanied with an increase in the initial (< 30 min) rate of heat evolution, and increasing CH generally reduced the time till the second maximum rate of heat evolution due to the formation of ettringite and monosulfate.

  7. Precursor preparation for Ca-Al layered double hydroxide to remove hexavalent chromium coexisting with calcium and magnesium chlorides

    NASA Astrophysics Data System (ADS)

    Zhong, Lihua; He, Xiaoman; Qu, Jun; Li, Xuewei; Lei, Zhiwu; Zhang, Qiwu; Liu, Xinzhong

    2017-01-01

    Al(OH)3 and Ca(OH)2 powders are co-ground to prepare a precursor which hydrates into a layered double hydroxide (LDH) phase by agitation in aqueous solution with target hexavalent chromium (Cr(VI)) at room temperature, to achieve an obvious improvement in removal efficiency of Cr(VI) through an easy incorporation into the structure. Although the prepared precursor transforms into LDH phases also when agitated in the solutions of calcium and magnesium chlorides, it incorporates Cr(VI) preferentially to the chloride salts when they coexist. The adsorption isotherm and kinetic studies show that the phenomena occurring on the Al-Ca precursor fit a pseudo-second-order kinetics with a Langmuir adsorption capacity of 59.45 mg/g. Besides, characterizations of the prepared precursor and the samples after adsorption are also performed by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Transmission electron microscope (TEM) to understand the reason of the preferential incorporation of Cr(VI) to the coexisting chloride salts during the LDH phase formation.

  8. The effects of calcium hydroxide on hydrogen chloride emission characteristics during a simulated densified refuse-derived fuel combustion process.

    PubMed

    Chiang, Kung-Yuh; Jih, Jer-Chyuan; Lin, Kae-Long

    2008-08-30

    This study investigated the effects of different calcium hydroxide (Ca(OH)(2)) addition methods on the potential for hydrogen chloride (HCl) formation in a simulated densified refuse-derived fuel (RDF-5) with single metal combustion system. These experiments were conducted at 850 degrees C with the Ca(OH)(2) spiked in the RDF-5 production or injection in the flue gas treatment system. The results indicated that the potential for HCl formation was decreased significantly by Ca(OH)(2) spiked in the RDF-5 production or injection in the flue gas treatment system. However, the Ca(OH)(2) injection method in the flue gas for HCl emission reduction was better than other method. According to the relationship between the HCl emission and amount of Ca(OH)(2) injected or spiked, it is interesting to find that when the Ca(OH)(2) injected or spiked ranged from 0% to 5%, the potential for HCl formation in the single metal combustion system decreases significantly with increasing Ca(OH)(2) injected or spiked ratio. A corresponding increase in the amount of CaCl(2) partitioned to the fly ash was observed. However, with the ratio of Ca(OH)(2) higher than 5%, the amount of HCl formation showed that no further significant variation occurred with increasing Ca(OH)(2) spiked ratio.

  9. Antibacterial Efficacy of Calcium Hydroxide and Chlorhexidine Mixture for Treatment of Teeth with Primary Endodontic Lesions: A Randomized Clinical Trial

    PubMed Central

    Donyavi, Zakiyeh; Ghahari, Parastoo; Esmaeilzadeh, Mohammad; Kharazifard, Mohammadjavad; Yousefi-Mashouf, Rasoul

    2016-01-01

    Introduction: This study compared the root canal microbial count of necrotic teeth after irrigation with 6% sodium hypochlorite (NaOCl) (single session treatment) and two-session root canal treatment with two-week application of calcium hydroxide (CH) mixed with 0.2% chlorhexidine (CHX) as intracanal medicament. Methods and Materials: In this randomized clinical trial, single-rooted necrotic teeth were divided into two groups. Root canal was irrigated with 2 mL of 6% NaOCl in one group, and a mixture of 0.2% CHX and CH powder as an intracanal medicament for two weeks, in the other group. Root canal samples were obtained before and after the intervention and number of colony forming units (CFUs) was counted in each phase. Results: The reduction of Enterococcus faecalis CFU was not significantly different between the two groups (P=0.233) but the CFU of aerobic and anaerobic bacteria was significantly lower in CH+CHX group (P<0.001). Conclusion: Two-week application of CH+CHX caused significant reduced the aerobic, anaerobic and E. faecalis colony counts. Thus, it may be beneficial to carry out primary root canal treatment of necrotic teeth with endodontic lesions in two sessions with intracanal medicaments to achieve predictable results. PMID:27790252

  10. Effect of treating sugarcane bagasse with urea and calcium hydroxide on feed intake, digestibility, and rumen fermentation in beef cattle.

    PubMed

    Gunun, Nirawan; Wanapat, Metha; Gunun, Pongsatorn; Cherdthong, Anusorn; Khejornsart, Pichad; Kang, Sungchhang

    2016-08-01

    Four beef cattle with initial body weight of 283 ± 14 kg were randomly allocated according to a 4 × 4 Latin square design to study on the effect of feeding sugarcane bagasse (SB) treated with urea and/or calcium hydroxide (Ca(OH)2) on feed intake, digestibility, and rumen fermentation. The treatments were as follows: rice straw (RS), untreated SB (SB), 4 % urea-treated SB (SBU), and 2 % urea + 2 % Ca(OH)2-treated SB (SBUC), respectively. The results revealed that cattle fed with SBU and SBUC had higher feed intake and apparent digestibility. Ammonia nitrogen and blood urea nitrogen were increased in cattle fed with SB as roughage source (P < 0.05). Feeding SBU and SBUC to cattle resulted in higher propionic acid and lower acetic acid, acetic to propionic ratio, and methane production (P < 0.05). Moreover, the number of fungi was increased in SBU- and SBUC-fed groups while protozoa population was unchanged. This study concluded that the nutritive value of SB was improved by urea and/or Ca(OH)2 treatment, and feeding treated SB could increase feed intake, digestibility, and rumen fermentation. This study suggested that SB treated with 2 % urea + 2 % Ca(OH)2 could be used as an alternative roughage source for ruminant feeding.

  11. Mineral trioxyde aggregate versus calcium hydroxide in apexification of non vital immature teeth: Study protocol for a randomized controlled trial

    PubMed Central

    2011-01-01

    Background Pulp necrosis is one of the main complications of dental trauma. When it happens on an immature tooth, pulp necrosis implies a lack of root maturation and apical closure. A therapy called apexification is required to induce the formation of a calcified apical barrier allowing a permanent and hermetic root filling. The aim of this prospective randomized clinical trial is to compare Mineral Trioxide Aggregate(MTA)with Calcium Hydroxide(CH)as materials used to induce root-end closure in necrotic permanent immature incisors. Methods/Design This study, promoted by AP-HP, was approved by the ethics committee(CPP Paris Ile de France IV). 34 children aged from 6 to 18 years and presenting a non-vital permanent incisor are selected. Prior to treatment, an appropriate written consent has to be obtained from both parents and from children. Patients are then randomly assigned to either the MTA(experimental)or CH(control)groups. Recalls are performed after 3, 6 and 12 months to determine the presence or absence of a calcified apical barrier through the use of clinical and radiographic exams. Additional criteria such as clinical symptoms, apical radiolucencies, periapical index(PAI)are also noted. Trial registration ClinicalTrials.gov no. NCT00472173 (First inclusion: May 10, 2007; Last inclusion: April 23, 2009; study completed: April 15, 2010) PMID:21752247

  12. A comparative study on dental pulp response to calcium hydroxide, white and grey mineral trioxide aggregate as pulp capping agents.

    PubMed

    Eskandarizadeh, Ali; Shahpasandzadeh, Mohammad Hossein; Shahpasandzadeh, Mahdieh; Torabi, Molok; Parirokh, Masoud

    2011-10-01

    Vital pulp therapy has been known as one of the treatment options to preserve pulp after being exposed by trauma or caries. To investigate human pulpal response to white and grey mineral trioxide aggregate (WMTA, GMTA) and Dycal (MTA) as pulp capping agents. Human volunteers were participated in this randomized clinical trial. This study was conducted on 90 intact first and second premolars of human maxillary and mandibular teeth. The teeth were randomly assigned into three groups of 30 each. Under local anesthesia, teeth were exposed and capped either with GMTA, WMTA, or Dycal. After 30, 60, and 90 days 10 teeth of each group were extracted and prepared for histologic observation. Histopathologic data were analyzed by χ(2), Kruskal Wallis and Mann Whitney tests. the calcified bridge in teeth that were capped with GMTA was significantly thicker than Dycal at 30 and 60 days (P= 0.015 and P=0.002, respectively); whereas WMTA showed significantly thicker calcified bridge than Dycal at 90 days (P=0.02). In addition, GMTA specimens showed significantly less inflammation compared to Dycal samples at 90 days interval (P=0.019). No significant difference was found between GMTA and WMTA in terms of calcified bridge thickness and pulp inflammatory response to the capping materials (P>0.05). Based on the result of this study, both types of MTA can be suggested as the materials of choice for direct pulp capping procedure instead of Dycal as hard setting calcium hydroxide cement.

  13. A comparison of human dental pulp response to calcium hydroxide and Biodentine as direct pulp-capping agents.

    PubMed

    Jalan, Anushka Lalit; Warhadpande, Manjusha M; Dakshindas, Darshan M

    2017-01-01

    Direct pulp capping involves the placement of a biocompatible agent on pulp tissue that has been inadvertently exposed from traumatic injury or by iatrogenic means. To compare the human pulp response to calcium hydroxide and Biodentine as direct pulp-capping agents. Pulp exposures were performed on the pulpal floor of forty human permanent premolars. The exposure sites were dressed with either Dycal or Biodentine as pulp-capping materials. After 45 days, teeth were extracted and processed for histological examination. The histological data were subjected to Wilcoxon rank-sum test. The dentinal bridges in teeth that were capped with Biodentine were significantly thicker (P < 0.0001) and more continuous (P = 0.0001) with less pulpal inflammation (P = 0.0044) in comparison to Dycal. Based on the result of this study, Biodentine can be suggested as the material of choice for direct pulp capping procedure instead of Dycal. However, further long-term follow-up in vivo human studies using Biodentine on cariously exposed pulpal teeth are warranted to derive a definite conclusion.

  14. Clinical and radiographic evaluation of indirect pulp treatment with MTA and calcium hydroxide in primary teeth (in-vivo study).

    PubMed

    George, Vimi; Janardhanan, Suresh Kumar; Varma, Balagopal; Kumaran, Parvathy; Xavier, Arun Mamachan

    2015-01-01

    Clinical and radiographic effects of mineral trioxide aggregate (white MTA) and calcium hydroxide (Dycal) in indirect pulp treatment (IPT) of primary teeth over a period of 6 months. A clinical trial with sample size of 40 primary molars between the age group of 5-9 years, of which, 20 teeth were considered, each for MTA and Dycal. Measurements on the digitized radiographs were performed at baseline, third and sixth month, increase in dentin was then measured using Corel Draw software. Independent t-test had indicated that at the end of 3 months and 6 months, a statistically significant increase in dentin thickness with both MTA and Dycal (P-value ≤ 0.001) was found. Within the MTA group, the thickness of dentin formed was 0.089 mm ± 0.031 mm at first 3 months and 0.055 ± 0.022 mm at the second 3 months, (P ≤ 0.001) evaluated using paired t-test. In the Dycal group, increment in dentin deposited was 0.068 mm at the first 3 months and second 3 months, it was 0.030 mm (P-value ≤ 0.001). Clinically and radiographically, MTA is superior to Dycal as a good IPT medicament in primary teeth.

  15. A comparison of human dental pulp response to calcium hydroxide and Biodentine as direct pulp-capping agents

    PubMed Central

    Jalan, Anushka Lalit; Warhadpande, Manjusha M.; Dakshindas, Darshan M.

    2017-01-01

    Context: Direct pulp capping involves the placement of a biocompatible agent on pulp tissue that has been inadvertently exposed from traumatic injury or by iatrogenic means. Aim: To compare the human pulp response to calcium hydroxide and Biodentine as direct pulp-capping agents. Materials and Methods: Pulp exposures were performed on the pulpal floor of forty human permanent premolars. The exposure sites were dressed with either Dycal or Biodentine as pulp-capping materials. After 45 days, teeth were extracted and processed for histological examination. Statistical Analysis: The histological data were subjected to Wilcoxon rank-sum test. Results: The dentinal bridges in teeth that were capped with Biodentine were significantly thicker (P < 0.0001) and more continuous (P = 0.0001) with less pulpal inflammation (P = 0.0044) in comparison to Dycal. Conclusion: Based on the result of this study, Biodentine can be suggested as the material of choice for direct pulp capping procedure instead of Dycal. However, further long-term follow-up in vivo human studies using Biodentine on cariously exposed pulpal teeth are warranted to derive a definite conclusion. PMID:28855762

  16. Retrievabilty of calcium hydroxide intracanal medicament with Chitosan from root canals: An in vitro CBCT volumetric analysis

    PubMed Central

    Vineeta, Nikhil; Gupta, Sachin; Chandra, Aditi

    2014-01-01

    Aim: This study compared the amount of aqueous-based and oil-based calcium hydroxide [Ca(OH)2 ] remaining in the canal, after removal with two different chelators 17% EDTA and 0.2% Chitosan in combination with ultrasonic agitation. Materials and Methods: Cleaning and shaping of root canals of 28 mandibular premolar was done and canals were filled either with Metapex or Ca(OH)2 mixed with distilled water. Volumetric analysis was performed utilizing cone beam-computed tomography (CBCT) after 7 days of incubation. Ca(OH)2 was removed using either 17% EDTA or 0.2% Chitosan in combination with ultrasonic agitation. Volumetric analysis was repeated and percentage difference was calculated and statistically analysed using Kruskal-Wallis and Mann-Whitney U test. Results: Both the chelators failed to remove aqueous-based as well as oil-based Ca(OH)2 completely from the root canal. Aqueous-based Ca(OH)2 was easier to be removed than oil-based Ca(OH)2. 0.2% Chitosan was significantly more effective for removal of oil-based Ca(OH)2 (P < 0.01) while both 17% EDTA and 0.2% Chitosan were equally effective in removing aqueous-based Ca(OH)2 . Conclusion: Combination of 0.2% Chitosan and ultrasonic agitation results in lower amount of Ca(OH)2 remnants than 17% EDTA irrespective of type of vehicle present in the mix. PMID:25298647

  17. The Influence of Dentine on the pH of Calcium Hydroxide, Chlorhexidine Gel, and Experimental Bioactive Glass-Based Root Canal Medicament

    PubMed Central

    Nunes Carvalho, Ceci; Gonzales Freire, Laila; Pinheiro Lima de Carvalho, Alexandre; Luiz Siqueira, Evandro; Bauer, José; Cunha Gritti, Giovana; Pereira de Souza, Juliana; Gavini, Giulio

    2015-01-01

    Objectives. To evaluate the influence of dentine on the pH of different medications in standardized simulated canals. Materials and Methods. Forty resin blocks were divided into groups with and without dentine powder, as follows: 2% chlorhexidine gel; 2% chlorhexidine gel associated with calcium hydroxide PA; calcium hydroxide PA delivered in propylene glycol 600; and NPG delivered in distilled water. The dentine powder was obtained from the root dentine of bovine teeth and added to the medications. The simulated canals were placed in containers with 1.5 mL of deionized water and pH was monitored in multiple intervals, up to 30 days. The mean pH values were calculated and submitted to statistical analysis using paired Student's t-test and ANOVA complemented by the Tukey test (p < 0.05). Results. There was no statistical difference between the groups with and without dentine powder (p > 0.05). The pH values of calcium hydroxide were significantly higher than those of NPG in the first 24 hours (p < 0.05). After 7 days, both behaved in a similar manner. Conclusion. The addition of dentine powder to the medications evaluated did not alter the pH of the external solution in any of the time points tested. PMID:26347249

  18. Comparative Evaluation of Clinical and Radiographic Success of Formocresol, Propolis, Turmeric Gel, and Calcium Hydroxide on Pulpotomized Primary Molars: A Preliminary Study.

    PubMed

    Hugar, Shivayogi M; Kukreja, Pratibha; Hugar, Shweta S; Gokhale, Niraj; Assudani, Harsha

    2017-01-01

    Despite various advents in technology, the present era marks a shift to phytotherapeutics and alternative modalities to conventional endodontic treatments. Newer endodontic modalities have been developed inculcating the ancient system of medicine. The present study was done to compare and evaluate the clinical pulp response and radiographic signs after pulpotomy in four groups of primary molar teeth treated with formocresol (control), propolis extract, turmeric gel, and calcium hydroxide respectively. Following ethical clearance, 90 primary molar teeth in 45 pediatric patients, aged between 4 and 9 years, were selected for pulpotomy. These were then randomly divided by split-mouth technique into two groups as experimental (propolis extract/turmeric gel/calcium hydroxide) and control (formocresol) groups. The patients were followed up for 6 months for clinical and radiographic signs and symptoms to evaluate the success of treatment. A comparable clinical and radiographic success rate was seen with all experimental groups as compared to the control (formocresol) group. With concerns about the safety of formocresol appearing in the dental and medical literature for more than 20 years, the materials used in this study can be considered as promising alternatives for formocresol in pediatric endodontic treatment. Hugar SM, Kukreja P, Hugar SS, Gokhale N, Assudani H. Comparative Evaluation of Clinical and Radiographic Success of Formocresol, Propolis, Turmeric Gel, and Calcium Hydroxide on Pulpotomized Primary Molars: A Preliminary Study. Int J Clin Pediatr Dent 2017;10(1):18-23.

  19. Comparative Evaluation of Clinical and Radiographic Success of Formocresol, Propolis, Turmeric Gel, and Calcium Hydroxide on Pulpotomized Primary Molars: A Preliminary Study

    PubMed Central

    Hugar, Shivayogi M; Hugar, Shweta S; Gokhale, Niraj; Assudani, Harsha

    2017-01-01

    Aims Despite various advents in technology, the present era marks a shift to phytotherapeutics and alternative modalities to conventional endodontic treatments. Newer endodontic modalities have been developed inculcating the ancient system of medicine. The present study was done to compare and evaluate the clinical pulp response and radiographic signs after pulpotomy in four groups of primary molar teeth treated with formocresol (control), propolis extract, turmeric gel, and calcium hydroxide respectively. Materials and methods Following ethical clearance, 90 primary molar teeth in 45 pediatric patients, aged between 4 and 9 years, were selected for pulpotomy. These were then randomly divided by split-mouth technique into two groups as experimental (propolis extract/turmeric gel/calcium hydroxide) and control (formocresol) groups. The patients were followed up for 6 months for clinical and radiographic signs and symptoms to evaluate the success of treatment. Results A comparable clinical and radiographic success rate was seen with all experimental groups as compared to the control (formocresol) group. Conclusion With concerns about the safety of formocresol appearing in the dental and medical literature for more than 20 years, the materials used in this study can be considered as promising alternatives for formocresol in pediatric endodontic treatment. How to cite this article Hugar SM, Kukreja P, Hugar SS, Gokhale N, Assudani H. Comparative Evaluation of Clinical and Radiographic Success of Formocresol, Propolis, Turmeric Gel, and Calcium Hydroxide on Pulpotomized Primary Molars: A Preliminary Study. Int J Clin Pediatr Dent 2017;10(1):18-23. PMID:28377649

  20. Retrievability of calcium hydroxide intracanal medicament with three calcium chelators, ethylenediaminetetraacetic acid, citric acid, and chitosan from root canals: An in vitro cone beam computed tomography volumetric analysis

    PubMed Central

    Raghu, Ramya; Pradeep, Geethu; Shetty, Ashish; Gautham, P. M.; Puneetha, P. G.; Reddy, T. V. Satyanarayana

    2017-01-01

    Aim: This study compared the amount of aqueous-based and oil-based calcium hydroxide remaining in the canal, after removal with two different chelators 17% EDTA, 20% Citric acid and 0.2% Chitosan in combination with ultrasonic agitation. Methods and Material: Cleaning and shaping of root canals of 28 mandibular premolar was done and canals were filled either with Metapex or Ca(OH)2 mixed with distilled water. Volumetric analysis was performed utilizing cone beam-computed tomography (CBCT) after seven days of incubation. Ca(OH)2 was removed using either 17% EDTA, 20% Citric acid or 0.2% Chitosan in combination with ultrasonic agitation. Statistical analysis used: Volumetric analysis was repeated and percentage difference was calculated and statistically analyzed using Kruskal-Wallis and Mann-Whitney U test. Results: All the three chelators failed to remove aqueous-based as well as oil-based Ca(OH)2 completely from the root canal. Aqueous-based Ca(OH)2 was easier to be removed than oil-based Ca(OH)2. 0.2% Chitosan in combination with ultrasonics performed better than 17% EDTA and 20% citric acid in removal of Ca(OH)2. Conclusion: Combination of 0.2% Chitosan and ultrasonic agitation results in lower amount of Ca(OH)2 remnants than 17% EDTA, 20% Citric acid irrespective of type of vehicle present in the mix. PMID:28761249

  1. Evaluation of calcium sulfate paste for augmentation of lumbar pedicle screw pullout strength.

    PubMed

    Rohmiller, Michael T; Schwalm, Dugan; Glattes, R Chris; Elalayli, Tarek G; Spengler, Dan M

    2002-01-01

    Many authors have evaluated the components responsible for ultimate pullout strength of pedicle screws. In these studies, one important variable has been the screw fixation. Because pedicle screw fixation has increased in popularity over recent years, so has the need for augmentation in difficult situations. Polymethylmethacrylate (PMMA) has been established as the gold standard in terms of strength of fixation but has the potential for severe complications when applied in spine surgery. Calcium sulfate is an alternative to PMMA, because it lacks the exothermic reaction, is potentially osteoconductive and is resorbed by the body in 30 to 60 days. To determine the strength of a new calcium sulfate cement in terms of pedicle screw augmentation. The purpose was to evaluate calcium sulfate versus PMMA in terms of pullout strength. PMMA was considered the gold standard in terms of strength for this experiment. Lumbar vertebrae implanted with pedicle screws were subjected to axial pullout tests. The force required to cause implant failure was measured and compared for three methods of fixation. Force to failure (Newtons) for each pedicle test was recorded and analyzed with results from similarly augmented pedicles. Lumbar vertebrae were harvested from four cadavers and implanted with pedicle screws. These screws were either placed in native bone or augmented with either calcium sulfate paste or PMMA. In those pedicles that had augmentation, the material was permitted to set for a minimum of 24 hours. Axial pullout tests were then performed using an MTS (Materials Testing System Corporation, Minneapolis, MN) testing machine. The screws were pulled out over a distance of up to 6 mm at 0.25 mm/sec. This rate and distance ensured failure in each case. The load to failure was recorded for each pedicle. Calcium sulfate augmentation improved pedicle screw pullout strength significantly when compared with native bone (p=.0003). This represented an average increase of 167% over

  2. Efficacy of different irrigation techniques in the removal of calcium hydroxide from a simulated internal root resorption cavity.

    PubMed

    Topçuoğlu, H S; Düzgün, S; Ceyhanlı, K T; Aktı, A; Pala, K; Kesim, B

    2015-04-01

    To evaluate the efficacy of six irrigation techniques to remove calcium hydroxide (CH) from a simulated internal root resorption cavity. The root canals of 100 single-rooted teeth were prepared using the ProTaper system to size F5. The roots were split longitudinally, and standardized simulated internal root resorption cavities were prepared in the two root halves. The root halves were reassembled, and CH was placed into the root canals, with the exception of five teeth that served as the negative control group. Another five teeth (the positive control group) were not subjected to the CH removal procedure. Ninety teeth were randomly divided into six experimental groups (n = 15), according to the final irrigation techniques used: conventional syringe irrigation (CSI), CanalBrush (CB), passive ultrasonic irrigation (PUI), self-adjusting file (SAF) system, EndoActivator (EA), and apical negative pressure irrigation (EndoVac system). Five millilitres of 3% NaOCl and 17% EDTA were used in all experimental groups during the CH removal procedure. The amount of remaining CH was evaluated under a stereomicroscope at 20 ×magnification, using a 4-grade scoring system. The data were statistically compared using the Kruskal-Wallis and Mann-Whitney U-tests (P < 0.05). Remnants of CH in simulated internal root resorption cavities were found in all experimental groups. SAF and PUI were superior to the other groups (P < 0.05); however, there was no significant difference between the SAF and PUI (P > 0.05). There were also no significant differences between the CSI, CB, EA and EndoVac groups (P > 0.05). None of the irrigation techniques was able to completely remove CH from a simulated internal root resorption cavity. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  3. The efficacy of the self-adjusting file and ProTaper for removal of calcium hydroxide from root canals

    PubMed Central

    FARIA, Gisele; KUGA, Milton Carlos; RUY, Alessandra Camila; ARANDA-GARCIA, Arturo Javier; BONETTI-FILHO, Idomeo; GUERREIRO-TANOMARU, Juliane Maria; LEONARDO, Renato Toledo

    2013-01-01

    Objective The goal of this study was to evaluate the efficacy of the Self-Adjusting File (SAF) and ProTaper for removing calcium hydroxide [Ca(OH)2] from root canals. Material and Methods Thirty-six human mandibular incisors were instrumented with the ProTaper system up to instrument F2 and filled with a Ca(OH)2-based dressing. After 7 days, specimens were distributed in two groups (n=15) according to the method of Ca(OH)2 removal. Group I (SAF) was irrigated with 5 mL of NaOCl and SAF was used for 30 seconds under constant irrigation with 5 mL of NaOCl using the Vatea irrigation device, followed by irrigation with 3 mL of EDTA and 5 mL of NaOCl. Group II (ProTaper) was irrigated with 5 mL of NaOCl, the F2 instrument was used for 30 seconds, followed by irrigation with 5 mL of NaOCl, 3 mL of EDTA, and 5 mL of NaOCl. In 3 teeth Ca(OH)2 was not removed (positive control) and in 3 teeth canals were not filled with Ca(OH)2 (negative control). Teeth were sectioned and prepared for the scanning electron microscopy. The amounts of residual Ca(OH)2 were evaluated in the middle and apical thirds using a 5-score system. Results None of the techniques completely removed the Ca(OH)2 dressing. No difference was observed between SAF and ProTaper in removing Ca(OH)2 in the middle (P=0.11) and the apical (P=0.23) thirds. Conclusion The SAF system showed similar efficacy to rotary instrument for removal of Ca(OH)2 from mandibular incisor root canals. PMID:24037074

  4. Calcium hydroxide dressing residues after different removal techniques affect the accuracy of Root-ZX apex locator

    PubMed Central

    Eymirli, Ayhan; Uyanik, Mehmet Özgür; Çalt, Semra; Nagas, Emre

    2015-01-01

    Objectives This study compared the ability of several techniques to remove calcium hydroxide (CH) from the root canal and determined the influence of CH residues on the accuracy of the electronic apex locator. Materials and Methods Root canals of 90 human maxillary lateral incisors with confirmed true working length (TWL) were prepared and filled with CH. The teeth were randomly assigned to one of the experimental groups according to the CH removal technique (n = 14): 0.9% saline; 0.9% saline + master apical file (MAF); 17% ethylenediamine tetraacetic acid (EDTA); 17% EDTA + MAF; 5.25% sodium hypochlorite (NaOCl); 5.25% NaOCl + MAF. Six teeth were used as negative control. After CH removal, the electronic working length was measured using Root-ZX (Morita Corp.) and compared with TWL to evaluate Root-ZX accuracy. All specimens were sectioned longitudinally, and the area of remaining CH (CH) and total canal area were measured using imaging software. Results The EDTA + MAF and NaOCl + MAF groups showed better CH removal than other groups (p < 0.05). Root-ZX reliability to prevent overestimated working length to be > 85% within a tolerance of ± 1.0 mm (p < 0.05). There was strong negative correlation between amount of CH residues and EAL accuracy (r = -0.800 for ± 0.5 mm; r = -0.940 for ± 1.0 mm). Conclusions The mechanical instrumentation improves the CH removal of irrigation solutions although none of the techniques removed the dressing completely. Residues of CH medication in root canals affected the accuracy of Root-ZX adversely. PMID:25671212

  5. A comparative study on dental pulp response to calcium hydroxide, white and grey mineral trioxide aggregate as pulp capping agents

    PubMed Central

    Eskandarizadeh, Ali; Shahpasandzadeh, Mohammad Hossein; Shahpasandzadeh, Mahdieh; Torabi, Molok; Parirokh, Masoud

    2011-01-01

    Context: Vital pulp therapy has been known as one of the treatment options to preserve pulp after being exposed by trauma or caries. Aim: To investigate human pulpal response to white and grey mineral trioxide aggregate (WMTA, GMTA) and Dycal (MTA) as pulp capping agents. Setting and Design: Human volunteers were participated in this randomized clinical trial. Materials and Methods: This study was conducted on 90 intact first and second premolars of human maxillary and mandibular teeth. The teeth were randomly assigned into three groups of 30 each. Under local anesthesia, teeth were exposed and capped either with GMTA, WMTA, or Dycal. After 30, 60, and 90 days 10 teeth of each group were extracted and prepared for histologic observation. Statistical Analysis: Histopathologic data were analyzed by χ2, Kruskal Wallis and Mann Whitney tests. Results: the calcified bridge in teeth that were capped with GMTA was significantly thicker than Dycal at 30 and 60 days (P= 0.015 and P=0.002, respectively); whereas WMTA showed significantly thicker calcified bridge than Dycal at 90 days (P=0.02). In addition, GMTA specimens showed significantly less inflammation compared to Dycal samples at 90 days interval (P=0.019). No significant difference was found between GMTA and WMTA in terms of calcified bridge thickness and pulp inflammatory response to the capping materials (P>0.05). Conclusions: Based on the result of this study, both types of MTA can be suggested as the materials of choice for direct pulp capping procedure instead of Dycal as hard setting calcium hydroxide cement. PMID:22144801

  6. Randomized control trial comparing calcium hydroxide and mineral trioxide aggregate for partial pulpotomies in cariously exposed pulps of permanent molars.

    PubMed

    Chailertvanitkul, P; Paphangkorakit, J; Sooksantisakoonchai, N; Pumas, N; Pairojamornyoot, W; Leela-Apiradee, N; Abbott, P V

    2014-09-01

    To compare the treatment outcomes when calcium hydroxide and mineral trioxide aggregate are used for partial pulpotomy in cariously exposed young permanent molars in a randomized control trial. Eighty-four teeth in 80 volunteers (aged 7-10 years) with reversible pulpitis and carious pulp exposures were randomly divided into two groups. Exposed pulps were severed using high-speed round burs until fresh pulp was seen. Cavities were irrigated with 2.5% sodium hypochlorite, and the pulp exposures were photographed and measured. Dycal or ProRoot MTA was placed on the pulp. Vitremer was placed over the material until the remaining cavity was 2 mm deep; amalgam was then placed. Teeth were evaluated for clinical symptoms and radiographic periapical changes after 24 h, 3 months, 6 months, 1 year and 2 years. Mean survival times and incidence of extraction were calculated using exact binomial confidence intervals. The median survival time for both ProRoot MTA and Dycal groups was 24 months. Three teeth had unfavourable outcomes with the incidence rate of 0.20/100 tooth-months with ProRoot MTA (95% CI: 0.02-0.71) and 0.11/100 tooth-months with Dycal (95% CI: 0.001-0.60). The incidence of unfavourable outcomes was 0.05/100 (95% CI: 0.001-0.30) and 2.38/100 (95% CI: 0.29-8.34) tooth-months in teeth with small (<5 mm(2) ) and large (>5 mm(2) ) pulp exposure areas, respectively. Partial pulpotomy in teeth of young patients with reversible pulpitis, either using ProRoot MTA or Dycal, resulted in favourable treatment outcomes for up to 2 years. The incidence of unfavourable outcomes tended to be higher in teeth with pulp exposure areas larger than 5 mm(2) . © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  7. Evaluation of the antibacterial effect of calcium hydroxide in combination with three different vehicles: An in vitro study

    PubMed Central

    Farhad, Ali Reza; Barekatain, Behnaz; Allameh, Maryam; Narimani, Tahmineh

    2012-01-01

    Introduction: Antimicrobial activity of interappointment intracanal medications is an important consideration in endodontics. Considering the fact that calcium hydroxide (CH) cannot sterilize the root canal system, completing its antimicrobial spectrum seems necessary. The aim of this study was to compare the antibacterial activity of CH combined with three different vehicles in root canal system. Materials and Methods: In this in vitro experimental study, 61 freshly extracted human single rooted teeth were used. After chemo-mechanical preparation, the teeth were dressed with CH in combination with: G1: Distilled water (DW); G2: 5.25% sodium hypochlorite; G3: 0.2% chlorhexidine solution. All teeth were mounted in a 2-chamber apparatus. After sterilization, the coronal chamber was exposed to bacteria and the apical chamber was filled with broth for 90 days. Leakage was recorded when turbidity was observed in broth. Mean times of leakage and turbidity percentage were recorded for each group. Data were analyzed by One Way ANOVA test (α=0.005). Results: The highest mean time of contamination was for chorhexidine/CH combination (M=66.76 days), and the lowest was for DW/CH combination (M=40.29 days). Statistically significant difference was observed between G3 and G1 (P=0.042), but the difference between G2 and G3 (P=0.76) or G1 and G2 (P=0.18) were not significant. 88.23% of the samples of G1, 70.58% of G2, and 64.70% of G3 were contaminated after 3 months. Conclusion: As an intracanal medication, the chlorhexidine/CH combination had significantly more antibacterial activity than DW/CH combination. PMID:22623933

  8. Comparison of particle morphology between commercial- and research-grade calcium hydroxide in endodontics.

    PubMed

    Komabayashi, Takashi; Ahn, Chul; Spears, Robert; Zhu, Qiang

    2014-09-01

    Ca(OH)2 aqueous slurry is widely used as an inter-appointment antimicrobial dressing in root canal treatment. The aim of this study was to quantify the particle size and shape of commercial-grade UltraCal XS (UC) and to compare it with that of research-grade Ca(OH)2 (RG) using a flow particle image analyzer (FPIA). The morphology and penetration inside the dentin tubules of the UC and RG particles were examined using a scanning electron microscope (SEM). UC and RG (10 mg) were mixed with 15 mL of alcohol, and were sonicated. Five milliliters of the dispersion was subjected to FPIA, and particle length, width, perimeter and aspect ratio were analyzed. In addition, UC paste and RG aqueous slurry were agitated on dentin discs and were prepared for SEM examination. There were significant differences between UC and RG with regard to the frequency of different length groups (P < 0.0001). UC contained smaller particles than RG (P < 0.0001). Under SEM, the agitated UC and RG particles occluded the opening of dentin tubules and penetrated inside the dentin tubules. The size of UC particles is smaller than those of RG. Both UC and RG particles were able to penetrate into open dentin tubules.

  9. Comparison of particle morphology between commercial- and research-grade calcium hydroxide in endodontics

    PubMed Central

    Komabayashi, Takashi; Ahn, Chul; Spears, Robert; Zhu, Qiang

    2014-01-01

    Ca(OH)2 aqueous slurry is widely used as an inter-appointment antimicrobial dressing in root canal treatment. The aim of this study was to quantify the particle size and shape of commercial-grade UltraCal XS (UC) and to compare it with that of research-grade Ca(OH)2 (RG) using a flow particle image analyzer (FPIA). The morphology and penetration inside the dentin tubules of the UC and RG particles were examined using a scanning electron microscope (SEM). UC and RG (10 mg) were mixed with 15 mL of alcohol, and were sonicated. Five milliliters of the dispersion was subjected to FPIA, and particle length, width, perimeter and aspect ratio were analyzed. In addition, UC paste and RG aqueous slurry were agitated on dentin discs and were prepared for SEM examination. There were significant differences between UC and RG with regard to the frequency of different length groups (P < 0.0001). UC contained smaller particles than RG (P < 0.0001). Under SEM, the agitated UC and RG particles occluded the opening of dentin tubules and penetrated inside the dentin tubules. The size of UC particles is smaller than those of RG. Both UC and RG particles were able to penetrate into open dentin tubules. PMID:25231145

  10. Efficacy of Erbium, Chromium-doped:Yttrium, Scandium, Gallium, and Garnet Laser Irradiation Combined with Resin-based Tricalcium Silicate and Calcium Hydroxide on Direct Pulp Capping: A Randomized Clinical Trial.

    PubMed

    Cengiz, Esra; Yilmaz, Hasan Guney

    2016-03-01

    The purpose of this randomized clinical study was to evaluate the efficiency of erbium, chromium-doped:yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser irradiation combined with a resin-based tricalcium silicate material and calcium hydroxide in direct pulp capping for a 6-month follow-up period. A total of 60 teeth of 60 patients between the ages of 18 and 41 years were recruited for this study. Sixty permanent vital teeth without symptoms and radiographic changes were randomly assigned to the following 4 groups (n = 15): Gr CH, the exposed area was sealed with calcium hydroxide (CH) paste; Gr laser CH, the treated area was sealed with CH paste after Er,Cr:YSGG laser irradiation at an energy level of 0.5 W without water and with 45% air; Gr TheraCal, TheraCal LC (Bisco, Schaumburg, IL) was applied directly to the exposed pulp; and Gr Laser TheraCal, TheraCal LC was applied after irradiation with an Er,Cr:YSGG laser. At the 1-week and 1-, 3-, and 6-month recall examinations, the loss of vitality, spontaneous pain, reactions to thermal stimuli and percussion, and radiographic changes were considered as failure. The success rates in the CH and TheraCal groups were 73.3% and 66.6%, respectively. These rates did not reveal any significant difference. In both laser groups, success rates were 100%. The Er,Cr:YSGG laser-irradiated TheraCal and Er,Cr:YSGG laser-irradiated CH groups showed statistically higher success rates than the TheraCal and CH groups, respectively. Er,Cr:YSGG laser irradiation at 0.5 W without water combined with pulp capping agents can be recommended for direct pulp therapy. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  11. Structural and nano-mechanical properties of Calcium Silicate Hydrate (C-S-H) formed from alite hydration in the presence of sodium and potassium hydroxide

    SciTech Connect

    Mendoza, Oscar; Giraldo, Carolina; Camargo, Sergio S.

    2015-08-15

    This research evaluates the effect of sodium and potassium hydroxide on the structure and nano-mechanical properties of Calcium Silicate Hydrate (C-S-H) formed from the hydration of pure alite. Monoclinic (MIII) alite was synthesized and hydrated, using water-to-alite ratios of 0.5 and 0.6 and additions of 10% NaOH and KOH by weight of alite. Based on results of X-ray diffraction, isothermal calorimetry, thermogravimetric analysis, Nuclear Magnetic Resonance and nanoindentation, two different effects of the alkaline hydroxides on the hydration reaction of alite, both at early and later ages, can be identified: (i) a differentiated hydration process, attributed to an enhancement in calcium hydroxide (CH) precipitation and a stimulation of the C-S-H nuclei; and (ii) an increase in the elastic modulus of the C-S-H aggregations, attributed to an electrostatic attraction between positive charges from the alkaline cations and negative charges from the C-S-H structure.

  12. Pulpal response to nano hydroxyapatite, mineral trioxide aggregate and calcium hydroxide when used as a direct pulp capping agent: an in vivo study.

    PubMed

    Swarup, S J; Rao, A; Boaz, K; Srikant, N; Shenoy, R

    2014-01-01

    Nano hydroxyapatite (Nano-HA) and Mineral Trioxide Aggregate (MTA) because of its better qualities can be used as an alternative to calcium hydroxide in direct pulp capping procedures. The aim of the study was to compare the response of exposed human pulp to Nano-HA, Mineral Trioxide Aggregate and calcium hydroxide. The study was done on 30 premolars, ranging from patients between 11-15 years. Intentional pulp capping was done using one of the experimental materials. The extracted teeth were then subjected to staining procedure and evaluated for dentin bridge and pulpal response after 15 and 30 days. Intragroup comparisons of the observed values were analyzed using Chi-square test. Nano-HA and MTA produced continuous dentin bridges. Dentin bridge that was formed in MTA group had regular pattern of dentinal tubules but no tubules were seen in the nano-HA group. Dentin bridge was not observed in Dycal group for the 15 days period in majority of the sample and by 30 days dentin bridge was observed that were both continuous and interrupted in equal number of samples. The initial inflammatory response and necrosis was more with Nano-HA and calcium hydroxide which reduced with time. MTA showed no inflammatory changes in majority of the samples in both the study periods. Necrosis was least observed in MTA group followed by Nano-HA. Vascularity increased in Nano-HA group in the initial periods which reduced with increasing time. Based on the ability of nano-HA to produce complete dentinal bridges, favorable cellular and vascular response, the material could be considered as an substitute and could be tried used as a direct pulp capping agent.

  13. Comparative Evaluation of Propolis, Metronidazole with Chlorhexidine, Calcium Hydroxide and Curcuma Longa Extract as Intracanal Medicament Against E.faecalis– An Invitro Study

    PubMed Central

    Nair, Rashmi; Asrani, Hemant

    2015-01-01

    Introduction The increase of potential side effects and safety concerns of conventional medicaments have led to the recent popularity of herbal alternative medications. The herbal products are known for its high antimicrobial activity, biocompatibility, anti-inflammatory and antioxidant properties. Aim The purpose of this study was to investigate and compare the effectiveness of Propolis, Metronidazole with Chlorhexidine gel, Curcuma Longa and Calcium Hydroxide for elimination of E.faecalis bacteria in extracted teeth samples. Materials and Methods Ninety extracted single rooted intact teeth were taken for the study. Decoronation, removal of apices and chemomechanical preparation was done for all samples. These sterilized samples were then contaminated with pure culture of E.faecalis under laminar flow. The samples were incubated for a period of 21 days. The infected samples were assigned to 5 groups: Group I- Propolis; Group II- Metronidazole with Chlorhexidine gel; Group III- Calcium hydroxide; Group IV- Curcuma Longa; and control group- Saline. Efficacy of newer intracanal medicaments against E.faecalis were carried out in the samples at the end of 1, 2 & 5 days for each group with the help of colorimeter. Student paired t-test, ANOVA and multiple tukey test were used for statistical analysis. Results The value of optical density was statistically significant in all groups when compared to that of control group. Group I (Propolis) produced better antimicrobial efficacy followed by Chlorhexidine Metronidazole combination, Curcuma Longa and Calcium hydroxide. Conclusion Within the limitations of this study, it can be concluded that Propolis showed better antimicrobial properties against E.faecalis than other medicaments. PMID:26673857

  14. In vitro evaluation of enamel remineralisation by a casein phosphopeptide-amorphous calcium phosphate paste.

    PubMed

    Willershausen, Brita; Schulz-Dobrick, Burkhard; Gleissner, Christiane

    2009-01-01

    The aim of this preliminary in vitro study was to evaluate the effect of a casein phosphopeptide and amorphous calcium phosphate (CPP-ACP) paste on untreated enamel surfaces that had previously been exposed to an erosive challenge. Over a period of 6 h, enamel samples from five fully erupted, caries-free molars were incubated with apple juice and later covered with CPP-ACP paste for 15 min. Enamel samples incubated with physiological sodium chloride solution or with apple juice alone served as controls. The quantitative elementary analysis for calcium and phosphorus in various depths ranging from 5 to 50 microm was performed using an electron-probe microanalyser. Exposure to apple juice resulted in a loss of minerals down to a depth of 30 microm with a mean loss of 13% at 5 microm and 6% at 10 microm. After treatment with CPP-ACP paste, the mineral loss decreased to a mean of 9% at 5 microm and remained at 5% at a depth of 10 microm (not a statistically significant difference). At a depth of 20 microm, no further mineral loss was recorded. This study demonstrated that there is a slight gain in the mineral contents after the application of a CPP-ACP paste, mainly in the upper enamel layer. Within the limitations of this in vitro study, the application of CPP-ACP paste may enhance the remineralisation after an erosive challenge and thus offer some protection for patients who are at risk for erosion.

  15. Antibacterial effect of calcium hydroxide combined with chlorhexidine on Enterococcus faecalis: a systematic review and meta-analysis

    PubMed Central

    SAATCHI, Masoud; SHOKRANEH, Ali; NAVAEI, Hooman; MARACY, Mohammad Reza; SHOJAEI, Hasan

    2014-01-01

    Objective Enterococcus faecalis (E. faecalis) is the most frequently isolated strain in failed endodontic therapy cases since it is resistant to calcium hydroxide (CH). Whether a combination of CH and chlorhexidine (CHX) is more effective than CH alone against E. faecalis is a matter of controversy. Thus, the aim of this study was to conduct a systematic review and meta-analysis of the literature. Material and Methods A comprehensive search in PubMed, EMbase, EBSCOhost, The Cochrane Library, SciELO, and BBO databases, Clinical trials registers, Open Grey, and conference proceedings from the earliest available date to February 1, 2013 was carried out and the relevant articles were identified by two independent reviewers. Backward and forward search was performed and then inclusion and exclusion criteria were applied. The included studies were divided into "comparisons" according to the depth of sampling and dressing period of each medicament. Meta-analysis was performed using Stata software 10.0. The level of significance was set at 0.05. Results Eighty-five studies were retrieved from databases and backward/forward searches. Fortyfive studies were considered as relevant (5 in vivo, 18 in vitro, 18 ex vivo, and 4 review articles). Nine studies were included for meta-analysis. Inter-observer agreement (Cohen kappa) was 0.93. The included studies were divided into 21 comparisons for meta-analysis. Chi-square test showed the comparisons were heterogeneous (p<0.001). Random effect model demonstrated no significant difference between CH/CHX mixture and CH alone in their effect on E. faecalis (p=0.115). Conclusions According to the evidence available now, mixing CH with CHX does not significantly increase the antimicrobial activity of CH against E. faecalis. It appears that mixing CH with CHX does not improve its ex vivo antibacterial property as an intracanal medicament against E. faecalis. Further in vivo studies are necessary to confirm and correlate the findings of

  16. Removal of Radioactively Marked Calcium Hydroxide from the Root Canal: Influence of Volume of Irrigation and Activation.

    PubMed

    Zorzin, José; Wießner, Jessica; Wießner, Thomas; Lohbauer, Ulrich; Petschelt, Anselm; Ebert, Johannes

    2016-04-01

    The purpose of this study was to evaluate the amount of calcium hydroxide (Ca[OH]2) removed by irrigation with different volumes and activation methods. One hundred thirty extracted straight, single-rooted human teeth were instrumented to size 45/.04. One hundred twenty teeth were filled with radioactively marked Ca(OH)2 and a gutta-percha point; 10 teeth with only gutta-percha served as a negative control. All specimens were stored in saline solution (7 days at 35°C). After storage, teeth were randomly divided into 12 groups (n = 10). The gutta-percha was taken out, and Ca(OH)2 was removed either by irrigation with different volumes (0 mL, 0.5 mL, 1 mL, 2 mL, 4 mL, or 8 mL) or mechanical activation with a 2- or 4-mL volume using a file (Instr) (FlexMaster size 45/.04; VDW, Munich, Germany), a brush (CanalBrush [CB]; Coltène/Whaledent, Langenau, Germany), or passive ultrasonic irrigation (PUI, smooth wire). Irrigation was performed by alternating 40% citric acid and 3% sodium hypochlorite. Residual Ca(OH)2 was measured by scintillation and expressed as a percentage of the original Ca(OH)2. Increasing the irrigation volume led to a significant decrease (P < .05) of residual Ca(OH)2 (0 mL [98.5%], 0.5 mL [21.7%], 1 mL [16.5%], 2 mL [12.9%], 4 mL [8.7%], 8 mL [5.0%], and negative control [0.0%]). Activation led to less residual Ca(OH)2 (2 mL Instr [12.0%], 2 mL CB [11.7%], 2 mL PUI [9.1%], 4 mL Instr [8.5%], 4 mL CB [7.4%], and 4 mL PUI [6.2%]), with significant differences according to the PUI (P < .05). No irrigation procedure was able to remove Ca(OH)2 completely. PUI was the most effective activation method. However, irrigation with an 8-mL volume was the most effective. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  17. Influence of calcium hydroxide-loaded microcapsules on osteoprotegerin and receptor activator of nuclear factor kappa B ligand activity.

    PubMed

    Han, Bing; Wang, Xiaoyan; Liu, Jiguang; Liang, Fuxin; Qu, Xiaozhong; Yang, Zhenzhong; Gao, Xuejun

    2014-12-01

    Calcium hydroxide (Ca[OH]2) microcapsules were synthesized to allow controlled release of Ca(OH)2. The aim of this study was to evaluate the influence of Ca(OH)2 microcapsules on osteoprotegerin (OPG) activity, receptor activator of nuclear factor kappa B ligand (RANKL) activity, and the OPG/RANKL ratio compared with pure Ca(OH)2 powder and Vitapex (Neo Dental Chemical Products Co Ltd, Tokyo, Japan). One formula of Ca(OH)2 microcapsules was evaluated, and pure Ca(OH)2 powder was used as a control. A commonly used Ca(OH)2 medication containing an oily vehicle (Vitapex) was also evaluated, and the in vitro release profile of Vitapex was studied. The human osteosarcoma cell line MG63 was used to evaluate the influence of Ca(OH)2 microcapsules, pure Ca(OH)2 powder, and Vitapex on OPG and RANKL activity. The relative messenger RNA (mRNA) expression of OPG and RANKL was determined by real-time polymerase chain reaction. The protein expression of OPG and RANKL in supernatants was measured using enzyme-linked immunosorbent assay. Vitapex prolonged the release of Ca(OH)2 compared with pure Ca(OH)2 powder, and the release rate of Vitapex was faster than that of the microcapsules. The OPG/RANKL ratio in the microcapsules group was up-regulated at both the mRNA and protein levels compared with the negative control group and the pure Ca(OH)2 powder group. The ratio in the Vitapex group was lower than the microcapsule group both at the mRNA and protein levels. Ca(OH)2 microcapsules increased the expression of OPG although they did not increase the expression of RANKL compared with pure Ca(OH)2 powder and Vitapex. This increase in expression led to an increase in the OPG/RANKL ratio and eventual inhibition of osteoclast activity. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  18. Removal of calcium hydroxide from Weine Type II systems using photon-induced photoacoustic streaming, passive ultrasonic, and needle irrigation: a microcomputed tomography study

    PubMed Central

    LLOYD, Adam; NAVARRETE, Geraldine; MARCHESAN, Melissa Andreia; CLEMENT, David

    2016-01-01

    ABSTRACT Objective This study compared the effectiveness of Er:YAG laser-activated irrigation (PIPS), passive ultrasonic irrigation (PUI) with EndoUltra and standard needle irrigation (SNI) in the removal of calcium hydroxide [Ca(OH)2] from the mesial roots of Weine Type II mandibular molars. Material and Methods Thirty mandibular molars were screened by µCT for the presence of mesial roots with complex intra-canal anatomy and a common apical foramen. The teeth were enlarged to a standardized 25/.06 preparation and filled with Ca(OH)2 paste. Specimens were divided into three groups (n=10) according to the technique used for Ca(OH)2 removal: PIPS, at 15 Hz and 20 mJ using a 9 mm long, 600 µm diameter tip; PUI using a 15/.02 tip; and SNI (30 Ga. side-vented needle). Equal volumes of 8.25% NaOCl and 17% EDTA were used in all groups. µCT was used to measure the initial amount of Ca(OH)2 present and to assess the residual volume of Ca(OH)2 following each irrigation protocol. Data were analyzed using Tukey HSD and Kruskal-Wallis tests (α=5%). Results The mean volume of Ca(OH)2 before removal was significantly higher in the coronal third than in the middle and apical third (p<0.001). Ca(OH)2 was similarly removed from the coronal and middle thirds with the three methods used (p>0.05). PIPS (median 0%; IQR: 0-0) showed significant higher Ca(OH)2 removal in the apical third than PUI (median 100%, IQR: 85-100) and SNI (median 47%; IQR: 16-72) (p<0.001). Conclusions PIPS laser-activation was more effective for the removal of Ca(OH)2 from mesial roots of mandibular molars with Weine Type II canal configurations than PUI with EndoUltra and SNI. PMID:28076457

  19. Treatment of open apex teeth using two types of white mineral trioxide aggregate after initial dressing with calcium hydroxide in children.

    PubMed

    Moore, Abigail; Howley, Mary Freda; O'Connell, Anne C

    2011-06-01

    The clinical and radiographic success of two types of white mineral trioxide aggregate (MTA) as apical barriers in non-vital immature permanent incisors in children was investigated. Following an initial dressing with calcium hydroxide, MTA apical barriers were placed in 22 non-vital traumatized, permanent incisors with open apices in 21 children (mean age 10years). Teeth were alternately assigned to either white MTA ProRoot(®) or white MTA Angelus groups and treated by two operators. Clinical and radiographic reviews took place at baseline, 3 months and every 6months thereafter. Two other calibrated, blinded examiners evaluated all radiographs. Examiner agreement was assessed using Kappa-Cohen tests. Results were analysed using Fisher's exact tests and repeated measures anova. The mean follow-up time was 23.4months. There were no statistically significant differences in clinical or radiographic outcomes between the two groups. The overall clinical success and relative radiographic success rate was 95.5%. Statistically significant reduction in periapical pathosis was shown over time in both groups (P<0.05). A significant relationship was identified between non-divergent apical anatomy and ideal positioning of the MTA plug in all teeth (P=0.04). Interestingly, coronal discolouration was observed in 22.7% of teeth following white MTA placement. Apical barrier placement using both white MTA ProRoot(®) and white MTA Angelus after an initial calcium hydroxide dressing showed similar favourable clinical and radiographic outcomes. © 2011 John Wiley & Sons A/S.

  20. Comparative efficacy of photo-activated disinfection and calcium hydroxide for disinfection of remaining carious dentin in deep cavities: a clinical study

    PubMed Central

    Sharma, Sidhartha; Shah, Naseem

    2014-01-01

    Objectives To comparatively evaluate the efficacy of photo-activated disinfection (PAD), calcium hydroxide (CH) and their combination on the treatment outcome of indirect pulp treatment (IPT). Materials and Methods Institutional ethical clearance and informed consent of the patients were taken. The study was also registered with clinical registry of India. Sixty permanent molars exhibiting deep occlusal carious lesion in patients with the age range of 18 - 22 yr were included. Clinical and radiographic evaluation and set inclusion and exclusion criteria's were followed. Gross caries excavation was accomplished. In group I (n = 20) PAD was applied for sixty seconds. In group II (n = 20), CH was applied to the remaining carious dentin, while in group III (n = 20), PAD application was followed by CH placement. The teeth were permanently restored. They were clinically and radiographically followed-up at 45 day, 6 mon and 12 mon. Relative density of the remaining affected dentin was measured by 'Radiovisiography (RVG) densitometric' analysis. Results Successful outcome with an increase in radiographic grey values were observed in all three groups. However, on inter-group comparison, this change was not significant (p > 0.05). Conclusions PAD and CH both have equal disinfection efficacy in the treatment of deep carious dentin. PAD alone is as effective for treatment of deep carious lesion as calcium hydroxide and hence can be used as an alternative to CH. They can be used independently in IPT, since combining both does not offer any additional therapeutic benefits. PMID:25110643

  1. Comparative efficacy of photo-activated disinfection and calcium hydroxide for disinfection of remaining carious dentin in deep cavities: a clinical study.

    PubMed

    Sharma, Sidhartha; Logani, Ajay; Shah, Naseem

    2014-08-01

    To comparatively evaluate the efficacy of photo-activated disinfection (PAD), calcium hydroxide (CH) and their combination on the treatment outcome of indirect pulp treatment (IPT). Institutional ethical clearance and informed consent of the patients were taken. The study was also registered with clinical registry of India. Sixty permanent molars exhibiting deep occlusal carious lesion in patients with the age range of 18 - 22 yr were included. Clinical and radiographic evaluation and set inclusion and exclusion criteria's were followed. Gross caries excavation was accomplished. In group I (n = 20) PAD was applied for sixty seconds. In group II (n = 20), CH was applied to the remaining carious dentin, while in group III (n = 20), PAD application was followed by CH placement. The teeth were permanently restored. They were clinically and radiographically followed-up at 45 day, 6 mon and 12 mon. Relative density of the remaining affected dentin was measured by 'Radiovisiography (RVG) densitometric' analysis. Successful outcome with an increase in radiographic grey values were observed in all three groups. However, on inter-group comparison, this change was not significant (p > 0.05). PAD and CH both have equal disinfection efficacy in the treatment of deep carious dentin. PAD alone is as effective for treatment of deep carious lesion as calcium hydroxide and hence can be used as an alternative to CH. They can be used independently in IPT, since combining both does not offer any additional therapeutic benefits.

  2. Antimicrobial efficacy of chlorhexidine and calcium hydroxide/camphorated paramonochlorophenol on infected primary molars: a split-mouth randomized clinical trial.

    PubMed

    Lima, Ramille Arújo; Carvalho, Cibele Barreto; Ribeiro, Thyciana Rodrigues; Fonteles, Cristiane Sá

    2013-02-01

    To compare via a split-mouth randomized clinical trial the efficacy of 1% chlorhexidine gel, calcium hydroxide/camphorated paramonochlorophenol (Callen PMCC), and a one-visit endodontic treatment against mutans streptococci and anaerobic bacteria found in primary molars with necrotic pulps and to assess clinical success rates after 12 months. Pre- and posttreatment intracanal samples were collected from 37 teeth (from 21 children) for analysis of the number of mutans streptococci and anaerobic bacteria. Clinical and radiographic criteria were analyzed to determine treatment outcome. Chlorhexidine gel significantly reduced mutans streptococci levels (P = .010), whereas Callen PMCC significantly reduced the levels of anaerobic bacteria (P = .002). No differences in the reduction of mutans streptococci (P = .187) and anaerobes (P = .564) were observed between groups. The clinical success rates were 85.71% (Callen PMCC), 78.57% (chlorexidine gel), and 77.77% (one-visit treatment). Teeth treated with Callen PMCC presented the highest clinical success rate. The 1% chlorhexidine gel, as well as calcium hydroxide/camphorated paramonochlorophenol, presented limited efficacy in reducing bacteria from necrotic primary root canals.

  3. Comparing the reinforcing effects of a resin modified glassionomer cement, Flowable compomer, and Flowable composite in the restoration of calcium hydroxide-treated immature roots in vitro.

    PubMed

    Prathibha, Rani S

    2011-01-01

    One hundred and sixty human permanent central incisors were enlarged to a 120 file size after crown removal procedure to simulate immature teeth. The root canals were filled with calcium hydroxide and stored for 15 days (phase I), 30 days (phase II), 90 days (phase III), and 180 days (Phase IV). At the end of these selected time periods, calcium hydroxide was cleaned off the root canals of forty teeth that were randomly selected and obturated with gutta-percha points in the apical 2 mm of the root canals with a sealer. The specimens were further equally divided into four groups. Unrestored Group I served as control and the root canals of teeth in the other three group specimens were reinforced with resin modified glassionomer cement (RMGIC) (Group II), Flowable Compomer (Group III), and Flowable Composite (Group IV), respectively, using a translucent curing post. All specimens were subjected to compressive force using an Instron Testing machine, until fracture occurred. All the materials evaluated substantially reinforced the root specimens compared to the control. At the end of 180 days, Flowable composites showed maximum reinforcement compared to the other groups; however, no significant differences were found between the reinforcement capabilities of Flowable Compomer and RMGIC.

  4. Orbital floor reconstruction using calcium phosphate cement paste: an animal study.

    PubMed

    Tañag, Marvin A; Yano, Kenji; Hosokawa, Ko

    2004-12-01

    Orbital floor defects were created in 10 New Zealand white rabbits and were reconstructed using an injectable calcium phosphate paste. These animals were euthanized at 2, 4, 8, and 12 months after implantation and were examined for biocompatibility and osteoconductivity. Grossly, implants were found to be adherent to the floor and covered with fibrous tissues. There was no sign of infection, extrusion, or migration of implant within the orbit and maxilla. The orbital floor was completely restored. Histological examination showed active new bone formation that encroached within the implant and gradually increased in density with time. Maxillary mucosa and glands were likewise reconstituted. Thin fibrovascular tissues were seen on top of and within the surface of the implant, and few to slight inflammatory cells were seen. Microradiography showed direct apposition between the new bone and the implant. These findings compare favorably with previously published reports on the biocompatibility and osteoconductivity of calcium phosphate cement. The authors believe that, together with ease of use and structural integrity, calcium phosphate paste can be useful in orbital floor reconstruction.

  5. The Calcium-Sensing Receptor and the Parathyroid: Past, Present, Future

    PubMed Central

    Conigrave, Arthur D.

    2016-01-01

    Parathyroid hormone (PTH) defends the extracellular fluid from hypocalcemia and has powerful and well-documented actions on the skeleton and renal tubular system. To achieve a satisfactory stable plasma calcium level, the secretion of PTH, and the resulting serum PTH level, is titrated carefully to the prevailing plasma ionized Ca2+ concentration via a Ca2+ sensing mechanism that mediates feedback inhibition of PTH secretion. Herein, I consider the properties of the parathyroid Ca2+ sensing mechanism, the identity of the Ca2+ sensor, the intracellular biochemical mechanisms that it controls, the manner of its integration with other components of the PTH secretion control mechanism, and its modulation by other nutrients. Together the well-established, recently elucidated, and yet-to-be discovered elements of the story constitute the past, present, and future of the parathyroid and its calcium-sensing receptor (CaSR). PMID:28018229

  6. The effects of calcium hydroxide-treated whole-plant and fractionated corn silage on intake, digestion, and lactation performance in dairy cows.

    PubMed

    Cook, D E; Bender, R W; Shinners, K J; Combs, D K

    2016-07-01

    The objective of this trial was to evaluate, in dairy cattle, the effects of calcium hydroxide treatment of whole-plant corn and a treatment applied to the bottom stalk fraction of the corn plant, achieved by harvesting corn in 2 crop streams. The treatments were calcium hydroxide-treated corn silage (TRTCS), toplage supplemented with calcium hydroxide-treated stalklage (TPL), a positive control of brown midrib corn silage (BMR), and a negative control of conventional whole-plant corn silage (WPCS). The toplage was harvested at a height of 82 cm with 2 of the 6 rows set as ear-snapping to incorporate higher tissues into the stalklage. Stalklage was harvested at 12 cm, and other corn silages were harvested at 27 cm. Sixteen pens, each with 8 Holstein cows averaging 70±25 d in milk and 46±11 kg of milk d(-1), were assigned 4 per treatment in a completely randomized design. The diet was approximately 40% corn silage, 20% alfalfa silage, and 40% concentrate on a dry matter basis. A 2-wk covariate period with conventional corn silage was followed by an 8-wk treatment period in which the 4 corn silage treatments were the only effective difference in diets. Cows fed TPL and TRTCS consumed more (1.9 and 1.4 kg of organic matter d(-1), respectively) than did cows fed WPCS. Milk yield was greater for cows fed BMR, TPL, and TRTCS. Cows fed BMR and TPL produced 2.9 and 2.7 kg d(-1), respectively, more energy-corrected milk (ECM) than cows fed WPCS, and cows fed TRTCS had the greatest ECM production (4.8 kg of ECM d(-1) greater than cows fed WPCS). No differences in body weight or body condition scored were observed. Milk fat concentration was similar among treatments and milk protein concentration was reduced for TRTCS. Starch and neutral detergent fiber digestibility were greater for cows fed TRTCS. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  7. Effect of feeding of calcium hydroxide-treated or vitamin E-supplemented cottonseed meal on plasma gossypol levels, blood parameters, and performance of Bikaneri lambs.

    PubMed

    Kannan, Alagarsamy; Sastry, Vadali Rama Bhadra; Agrawal, Dinesh Kumar; Kumar, Avneesh

    2013-08-01

    To study the effect of feeding calcium hydroxide-treated or vitamin E-supplemented cottonseed meal (CSM) incorporated diets on plasma gossypol, blood parameters and animal performance, 24 male Bikaneri lambs of 6-7 months of age and of uniform body weight were divided into four groups of six animals each in a completely randomized design and respectively fed isonitrogenous and isocaloric concentrate mixtures containing 20% soybean meal (CON) or 40% raw CSM (RCSM), 40% raw CSM supplemented with 500 IU of vitamin E per head per day (ERCSM), and 40%, 1.5% calcium hydroxide-treated CSM (CaCSM) along with ad libitum wheat straw throughout 510 days of experimental feeding. The lambs on all the diets grew linearly throughout the experimental period. The total weight gain, in turn the average daily gain (ADG), was not affected by dietary variations. The daily intake of dry matter, crude protein (CP), digestible crude protein (DCP) and total digestible nutrients (TDN) were found comparable among lambs of all the groups. Though total gossypol intake was similar in RCSM, ECSM and CaCSM groups, however, free gossypol intake was significantly higher (P < 0.01) in RCSM, ECSM groups as compared to CaCSM group. Serum iron and blood hemoglobin levels were significantly (P < 0.05) lower in RCSM group as compared to CaCSM and CON groups, and ALT activity was significantly (P < 0.05) higher on RCSM group as compared to other groups. Plasma gossypol and osmotic fragility of erythrocytes were significantly (P < 0.05) increased in RCSM group as compared to CaCSM and ERCSM groups. However, there was no significant difference in the concentration of other blood/serum biochemical constituents among the lambs on different groups. Based on the results, it may be concluded that feeding of 40% CSM in the concentrate mixture of the diet in Bikaneri lambs did not have any major adverse effect in blood parameters and animal performance. Either calcium hydroxide treatment or vitamin E

  8. Endodontic treatment of permanent teeth in children with a new calcium-carbamide-formaldehyde paste.

    PubMed

    Georgieva, Maria G; Indjova, Kalinka N; Indjov, Stefan I

    2002-01-01

    AIM, MATERIAL AND METHODS: Endodontic treatment of a total of 303 teeth with pulpitis and periodontitis was performed with a new calcium-carbamide-formaldehyde paste. In three children with fractured teeth with complications, the applied treatment was combined (2 teeth with apical osteotomy and 1 with cystectomy). Control examinations were carried out at months 6, 12 and 24 and clinically healthy teeth and teeth with complications were registered. In the pulpitis group the clinically healthy teeth were 97.55% +/- 1.08 at the 6th month; 96.85% +/- 1.26 at the 12th month and 92.92% +/- 2.41 at the 24th month. In teeth with periodontitis 91.56% +/- 3.05 were clinically healthy at the 6th month; 93.83% +/- 2.67 at the 12th month and 98.03% +/- 1.98 at the 24th month. No statistical significance of the differences between pulpites and periodontites was found (P > 0.05). Recovery of the bone structure was observed in the teeth with combined endodontic and surgical treatment at the 12th month. The calcium-carbamide-formaldehyde paste stimulates bone regeneration and closing of the apex without coloring the hard dental tissues.

  9. 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

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

    PubMed

    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

    2017-02-27

    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. 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. 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). The results suggest that the CLP based desensitizing paste has remineralization properties and provides instant and lasting effectiveness in dentinal tubule occlusion.

  11. Protective potential of casein phosphopeptide amorphous calcium phosphate containing paste on enamel surfaces.

    PubMed

    Somasundaram, Padmini; Vimala, N; Mandke, Lalita Gauri

    2013-03-01

    Dental caries remains the most common dental disease facing mankind. Prevention of initiation and interruption in progression of early lesions are the desirable modes of caries management. There is a scope for agents, which may be used to enhance anti - caries activity. This need has redirected research to develop novel preventive agents that can act as an adjunct to fluoride or independent of it. Casein Phosphopeptide - Amorphous Calcium Phosphate (CPP-ACP) is one such agent that has been proposed to have anti cariogenic properties. The purpose of this in vitro study was to evaluate the effect of paste containing CPP-ACP, MI Paste, on enamel remineralization. This study consisted of 30 samples embedded in orthodontic resin with either the buccal or lingual surface exposed. The samples were assigned to either a CPP-ACP containing paste; Fluoridated toothpaste; or a control group. The groups were then subjected to cycling in a demineralizing solution and a remineralizing solution. Groups II and III received prior application of MI paste and Fluoridated toothpaste respectively followed by cycling in a demineralizing solution and a remineralizing solution. Following 14 days of cycling, the samples were sectioned and examined using confocal microscopy. The lesion depth, were evaluated. Image Proplus software was used to analyze the images. The values were statistically evaluated using one - way ANOVA and Scheffe's Test. Within the limitations of the study it was concluded that enamel surfaces treated with the CPP-ACP paste exhibited the least lesion depths followed by the enamel surfaces treated with the fluoridated tooth paste and control group respectively.

  12. Protective potential of casein phosphopeptide amorphous calcium phosphate containing paste on enamel surfaces

    PubMed Central

    Somasundaram, Padmini; Vimala, N; Mandke, Lalita Gauri

    2013-01-01

    Background: Dental caries remains the most common dental disease facing mankind. Prevention of initiation and interruption in progression of early lesions are the desirable modes of caries management. There is a scope for agents, which may be used to enhance anti - caries activity. This need has redirected research to develop novel preventive agents that can act as an adjunct to fluoride or independent of it. Casein Phosphopeptide – Amorphous Calcium Phosphate (CPP-ACP) is one such agent that has been proposed to have anti cariogenic properties. Aim: The purpose of this in vitro study was to evaluate the effect of paste containing CPP-ACP, MI Paste, on enamel remineralization. Materials and Methods: This study consisted of 30 samples embedded in orthodontic resin with either the buccal or lingual surface exposed. The samples were assigned to either a CPP-ACP containing paste; Fluoridated toothpaste; or a control group. The groups were then subjected to cycling in a demineralizing solution and a remineralizing solution. Groups II and III received prior application of MI paste and Fluoridated toothpaste respectively followed by cycling in a demineralizing solution and a remineralizing solution. Following 14 days of cycling, the samples were sectioned and examined using confocal microscopy. The lesion depth, were evaluated. Statistical Analysis: Image Proplus software was used to analyze the images. The values were statistically evaluated using one – way ANOVA and Scheffe's Test. Results and Conclusion: Within the limitations of the study it was concluded that enamel surfaces treated with the CPP-ACP paste exhibited the least lesion depths followed by the enamel surfaces treated with the fluoridated tooth paste and control group respectively. PMID:23716969

  13. Comparative evaluation of calcium silicate-based dentin substitute (Biodentine®) and calcium hydroxide (pulpdent) in the formation of reactive dentin bridge in regenerative pulpotomy of vital primary teeth: Triple blind, randomized clinical trial

    PubMed Central

    Grewal, Navneet; Salhan, Rubica; Kaur, Nirapjeet; Patel, Hemal Bipin

    2016-01-01

    Background: Considering the biological concerns of calcium hydroxide (CH) as a pulpotomy agent, an alternative silicate based dentin substitute i.e. Biodentine (Ca3SiO5) was evaluated clinically and radiographically. Aims: To evaluate the effectiveness of dentin substitute (Biodentine) in regenerative pulpotomy of vital primary teeth that would giv a biological base to its use in forming reactive dentin bridge and overcoming the drawbacks of calcium hydroxide. Material and Methods: Randomised clinical trial on 40 bilateral carious primary molars in 20 participant children (aged 5-10 years) was carried out by same operator using Ca3SiO5(group-1) and CH (group-2) as vital pulpotomy agents. Blinded clinical and radiographic outcomes were observed at 3, 6 and 12 months interval. Results: Clinical outcomes of both protocols were analysed using Pearson's chi-square test applied at P < 0.05. Descriptive statistics were expressed as mean increase in dentin bridge formation in mms from two reference points in standardized radiographs using paired ‘t’- test at baseline and 12 months and found to be statistically significant (P < 0.05) in group-1 when compared with group-2. Conclusion: Group-1 revealed statistically favourable regenerative potential along with clinical success compared to group 2 thereby sharing both indications and mode of action with CH, but without its drawbacks of physical and clinical properties. PMID:27994411

  14. XPS depth profiling study on the passive oxide film of carbon steel in saturated calcium hydroxide solution and the effect of chloride on the film properties

    NASA Astrophysics Data System (ADS)

    Ghods, P.; Isgor, O. B.; Brown, J. R.; Bensebaa, F.; Kingston, D.

    2011-03-01

    X-ray photoelectron spectroscopy (XPS) was used to study the properties of passive oxide film that form on carbon steel in saturated calcium hydroxide solution and the effect of chloride on the film properties. The thickness of the oxide films was determined to be approximately 4 nm and was not affected by the exposure time. Near the film/substrate interface the concentration of the Fe2+ oxides was higher than the concentration of the Fe3+ oxides; the layers near the free surface of the film mostly contained Fe3+ oxides. Chloride exposure decreased the thickness of the oxide films and changed their stoichiometry such that near the film/substrate interface Fe3+/Fe2+ ratio increased.

  15. Antimicrobial effect of calcium hydroxide as an intracanal medicament in root canal treatment: a literature review - Part I. In vitro studies

    PubMed Central

    2014-01-01

    The goal of endodontic treatment is the prevention and control of pulpal and periradicular infections. Calcium hydroxide (Ca(OH)2) has been widely used in endodontics as an intracanal medicament to eliminate the remaining microorganisms after chemomechanical preparation. The purpose of this article is to review the antimicrobial properties of Ca(OH)2 as an intracanal medicament in root canal treatment. The first part of this review details the characteristics of Ca(OH)2 and summarizes the results of in vitro studies related to its antimicrobial effect. The antimicrobial effect of Ca(OH)2 results from the release of hydroxyl ions when it comes into contact with aqueous fluids. Ca(OH)2 has a wide range of antimicrobial effects against common endodontic pathogens, but is less effective against Enterococcus faecalis and Candida albicans. The addition of vehicles or other agents might contribute to the antimicrobial effect of Ca(OH)2. PMID:25383341

  16. A prospective clinical trial on the influence of a triamcinolone/demeclocycline and a calcium hydroxide based temporary cement on pain perception

    PubMed Central

    2012-01-01

    Introduction The aim of this clinical trial was to compare the degree of short term post-operative irritation after application of a triamcinolone/demeclocycyline based or a calcium hydroxide based provisional cement. Methods A total of 109 patients (55 female and 54 male; mean age: 51 ± 14 years) with primary or secondary dentinal caries were randomly assigned to the two treatment groups of this biomedical clinical trial (phase III). Selection criteria were good systemic health and treated teeth, which were vital and showed no symptoms of pulpitis. Up to three teeth were prepared for indirect metallic restorations, and the provisional restorations were cemented with a triamcinolone/demeclocycyline (Ledermix) or a calcium hydroxide (Provicol) based material. The intensity of post-operative pain experienced was documented according to the VAS (4, 12, 20, 24, and 82 h) and compared to VAS baseline. Results A total of 159 teeth were treated (Ledermix: 83 teeth, Provicol: 76 teeth). The minor irritation of the teeth, experienced prior to treatment, was similar in both groups; however, 4 h after treatment this value was significantly higher in the Provicol group than in the Ledermix group (p < 0.005, t-test). After 12 h, the difference was no longer significant. The number of patients taking analgesics for post-treatment pain was higher in the Provicol group (n = 11/53) than in the Ledermix group (n = 3/56). Conclusions The patients had no long term post-operative pain experience in both groups. However, within the first hours after cementation the sensation of pain was considerably higher in the Provicol group than in the Ledermix group. PMID:22414157

  17. Extent and mechanism of phase separation during the extrusion of calcium phosphate pastes.

    PubMed

    O'Neill, Rory; McCarthy, Helen O; Cunningham, Eoin; Montufar, Edgar; Ginebra, Maria-Pau; Wilson, D Ian; Lennon, Alex; Dunne, Nicholas

    2016-02-01

    The aim of this study was to increase understanding of the mechanism and dominant drivers influencing phase separation during ram extrusion of calcium phosphate (CaP) paste for orthopaedic applications. The liquid content of extrudate was determined, and the flow of liquid and powder phases within the syringe barrel during extrusion were observed, subject to various extrusion parameters. Increasing the initial liquid-to-powder mass ratio, LPR, (0.4-0.45), plunger rate (5-20 mm/min), and tapering the barrel exit (45°-90°) significantly reduced the extent of phase separation. Phase separation values ranged from (6.22 ± 0.69 to 18.94 ± 0.69 %). However altering needle geometry had no significant effect on phase separation. From powder tracing and liquid content determination, static zones of powder and a non-uniform liquid distribution was observed within the barrel. Measurements of extrudate and paste LPR within the barrel indicated that extrudate LPR remained constant during extrusion, while LPR of paste within the barrel decreased steadily. These observations indicate the mechanism of phase separation was located within the syringe barrel. Therefore phase separation can be attributed to either; (1) the liquid being forced downstream by an increase in pore pressure as a result of powder consolidation due to the pressure exerted by the plunger or (2) the liquid being drawn from paste within the barrel, due to suction, driven by dilation of the solids matrix at the barrel exit. Differentiating between these two mechanisms is difficult; however results obtained suggest that suction is the dominant phase separation mechanism occurring during extrusion of CaP paste.

  18. Effect of a calcium phosphate and fluoride paste on prevention of enamel demineralization.

    PubMed

    Nakata, Takuya; Kitasako, Yuichi; Sadr, Alireza; Nakashima, Syozi; Tagami, Junji

    2017-08-24

    This study aimed to examine the anti-demineralization capacities of (a) tetracalcium phosphate (TTCP) and dicalcium phosphate anhydrous (DCPA) and 950 ppm fluoride paste, (b) casein phosphopeptide amorphous calcium phosphate paste and (c) 950 ppm fluoride solution using optical coherence tomography (OCT). Enamel blocks were cut from the bovine incisors and treated using one of the above-mentioned three materials or deionized water as control (n=10). All samples were subjected to a demineralization gel for 1 h followed by a remineralization solution for 23 h. This experimental cycle was repeated for 28 days. The specimens were imaged using OCT at baseline and at four stages and measured lesion depth using image analysis software (ImageJ). Repeated measures ANOVA revealed that demineralization time, material and their interaction significantly affected the optical lesion depth (p<0.001). TTCP and DCPA and 950 ppm fluoride paste and 950 ppm fluoride solution showed significantly lower lesion progress compare to other groups (p<0.05).

  19. Aluminum Hydroxide

    MedlinePlus

    Aluminum hydroxide is used for the relief of heartburn, sour stomach, and peptic ulcer pain and to ... Aluminum hydroxide comes as a capsule, a tablet, and an oral liquid and suspension. The dose and ...

  20. An in vitro comparison of casein phosphopeptide-amorphous calcium phosphate paste, casein phosphopeptide-amorphous calcium phosphate paste with fluoride and casein phosphopeptide-amorphous calcium phosphate varnish on the inhibition of demineralization and promotion of remineralization of enamel.

    PubMed

    Thakkar, Prachi Jayesh; Badakar, Chandrashekhar M; Hugar, Shivayogi M; Hallikerimath, Seema; Patel, Punit M; Shah, Parin

    2017-01-01

    This study aims to determine and compare the extent of inhibition of demineralization and promotion of remineralization of permanent molar enamel with and without application of three remineralizing agents. Forty extracted permanent molars were randomly divided into two groups 1 and 2, longitudinally sectioned into four and divided into subgroups A, B, C, and D. The sections were coated with nail varnish leaving a window of 3 mm × 3 mm. All sections of Group 1 were treated with their respective subgroup-specific agent: Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste for subgroup A, CPP-amorphous calcium phosphate fluoride (ACPF) paste for subgroup B, CPP-ACPF varnish for subgroup C and subgroup D served as a control. The sections were then subjected to demineralization for 12 days following which lesional depth was measured under the stereomicroscope. All the sections of Group 2 were subjected to demineralization for 12 days, examined for lesional depth, then treated with their respective subgroup specific agents and immersed in artificial saliva for 7 days. The sections were then examined again under the stereomicroscope to measure the lesional depth. CPP-ACPF varnish caused significant inhibition of demineralization. All three agents showed significant remineralization of previously demineralized lesions. However, CPP-ACPF varnish showed the greatest remineralization, followed by CPP-ACPF paste and then CPP-ACP paste. This study shows that CPP-ACPF varnish is effective in preventing demineralization as well as promoting remineralization of enamel. Thus, it can be used as an effective preventive measure for pediatric patients where compliance with the use of tooth mousse may be questionable.

  1. Effects of calcium leaching on diffusion properties of hardened and altered cement pastes

    NASA Astrophysics Data System (ADS)

    Kurumisawa, Kiyofumi; Haga, Kazuko; Hayashi, Daisuke; Owada, Hitoshi

    2017-06-01

    It is very important to predict alterations in the concrete used for fabricating disposal containers for radioactive waste. Therefore, it is necessary to understand the alteration of cementitious materials caused by calcium leaching when they are in contact with ground water in the long term. To evaluate the long-term transport characteristics of cementitious materials, the microstructural behavior of these materials should be considered. However, many predictive models of transport characteristics focus on the pore structure, while only few such models consider both, the spatial distribution of calcium silicate hydrate (C-S-H), portlandite, and the pore spaces. This study focused on the spatial distribution of these cement phases. The auto-correlation function of each phase of cementitious materials was calculated from two-dimensional backscattered electron imaging, and the three-dimensional spatial image of the cementitious material was produced using these auto-correlation functions. An attempt was made to estimate the diffusion coefficient of chloride from the three-dimensional spatial image. The estimated diffusion coefficient of the altered sample from the three-dimensional spatial image was found to be comparable to the measured value. This demonstrated that it is possible to predict the diffusion coefficient of the altered cement paste by using the proposed model.

  2. Injection of calcium phosphate pastes: prediction of injection force and comparison with experiments.

    PubMed

    Fatimi, Ahmed; Tassin, Jean-François; Bosco, Julia; Deterre, Rémi; Axelos, Monique A V; Weiss, Pierre

    2012-07-01

    Calcium phosphate ceramics suspensions (ICPCS) are used in bone and dental surgery as injectable bone substitutes. This ICPCS biomaterial associates biphasic calcium phosphate (BCP) granules with hydroxypropylmethylcellulose (HPMC) polymer. Different ICPCS were prepared and their rheological properties were evaluated in parallel disks geometry as a function of the BCP weight ratio (35, 40, 45 and 50 %). The suspensions show a strongly increased viscosity as compared to the suspending fluid and the high shear rate part of the flow curve can be fitted with a power law model (Ostwald-de Waele model). The fitting parameters depend on the composition of the suspension. A simple device has been used to characterize extrusion of the paste using a disposable syringe fitted with a needle. The injection pressure of four ICPCS formulations was studied under various conditions (needle length and radius and volumetric flow rate), yielding an important set of data. A theoretical approach based on the capillary flow of non-Newtonian fluids was used to predict the necessary pressure for injection, on the basis of flow curves and extrusion conditions. The extrusion pressure calculated from rheological data shows a quantitative agreement with the experimental one for model fluids (Newtonian and HPMC solution) but also for the suspension, when needles with sufficiently large diameters as compared to the size of particles, are used. Depletion and possibly wall slip is encountered in the suspensions when narrower diameters are used, so that the injection pressure is less than that anticipated. However a constant proportionality factor exists between theory and injection experiments. The approach developed in this study can be used to correlate the rheological parameters to the necessary pressure for injection and defines the pertinent experimental conditions to obtain a quantitative agreement between theory and experiments.

  3. Effect of dental materials calcium hydroxide-containing cement, mineral trioxide aggregate, and enamel matrix derivative on proliferation and differentiation of human tooth germ stem cells.

    PubMed

    Guven, Esra Pamukcu; Yalvac, Mehmet Emir; Sahin, Fikrettin; Yazici, Munevver M; Rizvanov, Albert A; Bayirli, Gunduz

    2011-05-01

    Biocompatibility of pulp capping materials is important for successful use in dentistry. These materials should be nontoxic and permissive for proliferation and induction of odontogenic differentiation of pulp cells. The aim of our study was to evaluate the effects of enamel matrix derivative (EMD), mineral trioxide aggregate (MTA), and calcium hydroxide-containing cement (DYCAL) on proliferation and odontogenic differentiation of human tooth germ stem cells (hTGSCs) in which cells belonging to both pulp tissue and dental follicle exist. The 96-well plates, 24-well plates, and special chamber slides were coated with biomaterials for cell proliferation, differentiation, and scanning electron microscopy analysis. Odontogenic differentiation of hTGSCs was evaluated by analyzing mRNA expression of dentin sialophosphoprotein (DSPP) by real-time polymerase chain reaction expression analysis, measurement of alkaline phosphatase activity, and visualization of calcium depositions by von Kossa staining. Our results demonstrate that EMD is the best material in terms of inducing differentiation and proliferation of hTGSCs. DYCAL was found to be toxic to hTGSCs; however, EMD-coated DYCAL showed less toxicity. EMD-coated MTA was not efficient at inducing proliferation and differentiation. Pulp capping materials come in direct contact with dental pulp cells; thus, they require comprehensive evaluation of interactions between cells and biomaterials. Therefore, we cultured hTGSCs, capable of odontogenic differentiation, on pulp capping materials directly. Our results suggest that combination of capping materials with EMD would increase the quality of capping by increasing biocompatibility of capping materials. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  4. Direct Pulp Capping with Calcium Hydroxide, Mineral Trioxide Aggregate, and Biodentine in Permanent Young Teeth with Caries: A Randomized Clinical Trial.

    PubMed

    Brizuela, Claudia; Ormeño, Andrea; Cabrera, Carolina; Cabezas, Roxana; Silva, Carolina Inostroza; Ramírez, Valeria; Mercade, Montse

    2017-09-13

    Direct pulp capping treatment is intended to preserve pulp vitality, to avoid or retard root canal treatment, and, in cases with an open apex, to allow continued root development. Historically, calcium hydroxide (CH) was the gold standard material, but nowadays calcium silicate materials (CSMs) are displacing CH because of their high bioactivity, biocompatibility, sealing ability, and mechanical properties. However, more randomized clinical trials are needed to confirm the appropriateness of CSMs as replacement materials for CH in direct pulp capping procedures. A randomized clinical trial was conducted that included 169 patients (mean age, 11.3 years) from the Maipo district (Chile). The inclusion criterion was patients with 1 carious permanent tooth with pulpal exposure, a candidate for a direct pulp capping procedure. The patients were randomly allocated to one of the experimental groups (CH, Biodentine, or mineral trioxide aggregate [MTA]). Clinical follow-up examinations were performed at 1 week, 3 months, 6 months, and 1 year. The Fisher exact test was performed. At the follow-up examination at 1 week, the patients showed 100% clinical success. At 3 months, there was 1 failure in the CH group. At 6 months, there were 4 new failures (1 in the CH group and 3 in the MTA group). At 1 year, there was another failure in the CH group. There were no statistically significant differences among the experimental groups. CSMs appear to be suitable materials to replace CH. Although no significant differences were found among the materials studied, Biodentine and MTA offered some advantages over CH. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. The enhancement effect of pre-reduction using zero-valent iron on the solidification of chromite ore processing residue by blast furnace slag and calcium hydroxide.

    PubMed

    Li, Jinchunzi; Chen, Zhonglin; Shen, Jimin; Wang, Binyuan; Fan, Leitao

    2015-09-01

    A bench scale study was performed to assess the effectiveness of the solidification of chromite ore processing residue (COPR) by blast furnace slag and calcium hydroxide, and investigate the enhancement effect of pre-reduction using zero-valent iron (ZVI) on the solidification treatment. The degree of Cr immobilization was evaluated using the Toxicity Characteristic Leaching Procedure (TCLP) as well as the solid waste-extraction procedure for leaching toxicity-sulfuric acid & nitric acid method (Chinese standard HJ/T299-2007). Strength tests and semi-dynamic leaching tests were implemented to investigate the potential for reusing the final treatment product as a readily available construction material. The experimental results showed that the performance of pre-reduction/solidification (S/S) was superior to that of solidification alone. After pre-reduction, all of the S/S treated COPR samples met the TCLP limit for total Cr (5 mg L(-1)), whereas the samples with a COPR content below 40% met the pollution control limit of bricks and building block products (Chinese standard HJ/T 301-2007) produced with COPR for total Cr (0.3 mg L(-1)). At the same time, all of the S/S treated specimens tested were suitable for utilization at certain levels.

  6. Cd immobilization in a contaminated rice paddy by inorganic stabilizers of calcium hydroxide and silicon slag and by organic stabilizer of biochar.

    PubMed

    Bian, Rongjun; Li, Lianqing; Bao, Dandan; Zheng, Jinwei; Zhang, Xuhui; Zheng, Jufeng; Liu, Xiaoyu; Cheng, Kun; Pan, Genxing

    2016-05-01

    A field experiment was conducted in a Cd-contaminated rice paddy field to evaluate the effect of inorganic and organic metal stabilizers on Cd mobility and rice uptake. A dose of inorganic stabilizer of calcium hydroxide (CH), silicon slag (SS), and wheat straw biochar (BC) was amended respectively to topsoil before rice transplanting. Rice production was managed with the same water regime and fertilization practices consistently between treatments including a control without amendment. Samples of topsoil and rice plant were collected at rice harvest to analyze the Cd mobility and uptake by rice. Without affecting rice grain yield, the stabilizers significantly decreased CaCl2-extractable Cd in a range of 44 to 75 % compared to the control, corresponding to soil pH changes under the different treatments. Accordingly, Cd concentrations both in rice tissue and in rice grain were very significantly decreased under these treatments. The decrease in rice Cd uptake was correlated to the decrease in extractable Cd, which was again correlated to soil pH change under the different treatments, indicating a prevalent role of liming effect by the amendments. While applied at a large amount in a single year, organic stabilizer of BC decreased Cd extractability by up to 43 % and Cd rice uptake by up to 61 %, being the most effective on Cd immobilization. However, the long-term effect on soil health and potential tradeoff effects with different stabilizers deserve further field monitoring studies.

  7. Dentinal tubule disinfection with 2% chlorhexidine, garlic extract, and calcium hydroxide against Enterococcus faecalis by using real-time polymerase chain reaction: In vitro study

    PubMed Central

    Eswar, Kandaswamy; Venkateshbabu, Nagendrababu; Rajeswari, Kalaiselvam; Kandaswamy, Deivanayagam

    2013-01-01

    Aim: To compare the efficacy of garlic extract with 2% chlorhexidine (CHX) and calcium hydroxide Ca(OH)2 in disinfection of dentinal tubules contaminated with Enterococcus faecalis by using real-time polymerase chain reaction (PCR). Materials and Methods: Agar diffusion test was done to evaluate the minimum inhibitory concentration of garlic extract against E. faecalis. Forty human extracted mandibular premolar teeth were selected for this study, access cavity was prepared and cleaning and shaping was done. Middle third of the root was cut using a rotary diamond disc. The teeth specimens were inoculated with E. faecalis for 21 days. Specimens were divided into four groups---Group 1: 2% CHX, Group 2: Garlic extract, Group 3: Ca(OH)2, and Group 4: Saline (negative control). The intracanal medicaments were packed inside the tooth specimens and incubated for 5 days. The dentinal chips were collected at 400 μm depth using a Gates-Glidden drill, following which DNA isolation was done. The specimens were analyzed using real-time PCR. The results were then statistically analyzed using one-way analysis of variance, followed by post hoc Tukey's honestly significant difference (HSD) multiple comparison of means. Results: Threshold cycle (Ct) values of 2% CHX was found to be 32.4, garlic extract to be 27.5, and Ca(OH)2 to be 25.6. Conclusion: A total of 2% CHX showed the maximum efficacy against E. faecalis, followed by garlic extract and Ca(OH)2. PMID:23833449

  8. Effect of addition of lycopene to calcium hydroxide and chlorhexidine as intracanal medicament on fracture resistance of radicular dentin at two different time intervals: An in vitro study

    PubMed Central

    Madhusudhana, Koppolu; Archanagupta, Kasamsetty; Suneelkumar, Chinni; Lavanya, Anumula; Deepthi, Mandava

    2015-01-01

    Background: Long-term use of intracanal medicaments such as calcium hydroxide (CH) reduces the fracture resistance of dentin. The present study was undertaken to evaluate the fracture resistance of radicular dentin on long-term use of CH, chlorhexidine (CHX) with lycopene (LP). Aim: To compare the fracture resistance of radicular dentin when intracanal medicaments such as CH, CHX with LP were used for 1-week and 1-month time interval. Settings and Design: Sixty single-rooted extracted human permanent premolars were collected, and complete instrumentation was done. Samples were divided into three groups based on intracanal medicament used. Materials and Methods: Group 1 - no medicament was placed (CON), group 2 - mixture of 1.5 g of CH and 1 ml of 2% CHX (CHCHX), group 3 - mixture of 1.5 g of CH, 1 ml of CHX and 1 ml of 5% LP solution (CHCHXLP). After storage period of each group for 1-week and 1-month, middle 8 mm root cylinder was sectioned and tested for fracture resistance. Statistical Analysis: Results were analyzed using paired t-test. Results: At 1-month time interval, there was a statistically significant difference in fracture resistance between CHCHX and CHCHXLP groups. Conclusion: Addition of LP has not decreased the fracture resistance of radicular dentin after 1-month. PMID:26069405

  9. Clinical and radiographic assessment of mineral trioxide aggregate and calcium hydroxide as apexification agents in traumatized young permanent anterior teeth: A comparative study

    PubMed Central

    Damle, S. G.; Bhattal, Hiteshwar; Damle, Dhanashree; Dhindsa, Abhishek; Loomba, Ashish; Singla, Sumit

    2016-01-01

    Background: To evaluate and compare the efficacy of mineral trioxide aggregate (MTA) and traditionally used calcium hydroxide (Ca(OH)2) in inducing root end formation of immature roots of traumatized young permanent anterior teeth. Materials and Methods: The study was carried out on 22 nonvital, immature permanent maxillary incisors. Samples were allotted into two groups - Group I MTA and Group II Ca(OH)2 Success rate was determined based upon the time duration required for apical barrier formation. The canals were obturated using gutta-percha points in MTA group, after 24 h, whereas in Ca(OH)2 group, obturation was carried out after radiographic confirmation of the apical barrier. The clinical and radiographic evaluation was carried out at a follow-up periods of 3, 6, and 9 months and statistical analysis was carried out by SPSS version 15.0 statistical analysis software (Chi-square test and fisher exact test). Results: In MTA Group, barrier formation was observed in 90.90% of the patients after 9 months whereas in Ca(OH)2 Group, the same was observed in 81.81%. The mean time required for barrier formation in MTA group was 4.90 months and 5.33 months in Ca(OH)2 group. Conclusion: MTA and Ca(OH)2, as medicaments for apexification, were comparable in terms of the evaluation parameters. However, MTA was beneficial in terms of immediate obturation of immature roots with wide open apices. PMID:27274351

  10. Incorporation of anti-inflammatory agent into calcium hydroxide pulp capping material: an in vitro study of physical and mechanical properties.

    PubMed

    Louwakul, Phumisak; Lertchirakarn, Veera

    2012-02-03

    The aims of this study were to investigate the release of fluocinolone acetonide from an experimental pulp capping material containing fluocinolone acetonide (PCFA) and compare some physical and mechanical properties with Dycal(®). The PCFA is a hard-setting calcium hydroxide cement composed of 50 mmol/L fluocinolone acetonide. Conditioned media from the setting material was collected for determination of fluocinolone acetonide release by high performance liquid chromatography and pH measurement by pH meter. The setting time, compressive strength, disintegration, and acid soluble arsenic content were measured according to ISO 3107:2004. Dycal(®) was used as control. Fluocinolone acetonide could release at a range of suitable concentrations from PCFA. The pH, setting time, and acid soluble arsenic content of PCFA were significantly higher than those of Dycal(®). The compressive strength and disintegration of PCFA were comparable to control. PCFA may be considered as an alternative in pulp capping of inflamed dental pulp tissue.

  11. Efficacy of sodium hypochlorite, ethylenediaminetetraacetic acid, citric acid and phosphoric acid in calcium hydroxide removal from the root canal: a microscopic cleanliness evaluation.

    PubMed

    da Silva, Juliana Melo; Silveira, Amanda; Santos, Elizandra; Prado, Laiìs; Pessoa, Oscar F

    2011-12-01

    Rooted molars were subjected to standardized canal instrumentation to a master apical file (MAF). The samples were dressed with Ca(OH)(2), and after 7 days, teeth were reopened and Ca(OH)(2) medication was removed by 1 of 4 different experimental procedures: 2.5% sodium hypochlorite (NaOCl) (n = 10); 17% EDTA-T (n = 10); 10% citric acid (n = 10); or 37% phosphoric acid (n = 10). This was followed by reinstrumentation with MAF plus 15 mL saline solution. The roots were prepared for scanning electron microscopic analysis of the cervical, middle, and apical thirds. Statistical analysis was performed with the Kruskal-Wallis test. EDTA-T and phosphoric acid gave the best results in the apical third, with significant statistical differences compared with other groups. NaOCl gave the worst results. Irrigation with 17% EDTA-T and 37% phosphoric acid is more effective than sodium hypochlorite and citric acid in the removal of calcium hydroxide from the apical third. Copyright © 2011 Mosby, Inc. All rights reserved.

  12. Influence of porosity and relative humidity on consolidation of dolostone with calcium hydroxide nanoparticles: Effectiveness assessment with non-destructive techniques

    SciTech Connect

    Lopez-Arce, P.; Gomez-Villalba, L.S.; Pinho, L.; Fernandez-Valle, M.E.; Alvarez de Buergo, M.; Fort, R.

    2010-02-15

    Slaked lime (Ca(OH){sub 2}) nanoparticles were exposed at 33% and 75% relative humidity (RH) to consolidate dolostone samples used in historical buildings. Non-destructive techniques (NDT) were applied to determine the chemical, morphological, physical and hydric properties of the stone samples, before and after 20 days treatment. Morphological and mineralogical characterisation of the nanoparticles was performed. 75% RH favors the consolidation process studied under Environmental Scanning Electron Microscopy (ESEM-EDS), spectrophotometry, capillarity, water absorption under vacuum, ultrasound velocity, Nuclear Magnetic Resonance (imaging and relaxometry) and Optical Surface Roughness analyses. At 75% RH the nanoparticles fill the pores and inter-crystalline dolomite grain contacts but do not favor calcite re-crystallization as it occurs at 33% RH. The ESEM, XRD and TEM analyses under 75% RH reveal the fast transformation of portlandite (Ca(OH){sub 2}) into vaterite (CaCO{sub 3}), monohydrocalcite (CaCO{sub 3} . H{sub 2}O) and calcite (CaCO{sub 3}), and eventually the physical and hydric properties of the stones significantly improve. New insights are provided for the assessment of consolidation effectiveness of porous carbonate stones with calcium hydroxide nanoparticles under optimum RH conditions combining several NDT.

  13. Antibacterial activity of calcium hydroxide combined with chitosan solutions and the outcomes on the bond strength of RealSeal sealer to radicular dentin

    PubMed Central

    Elsaka, Shaymaa Elsayed; Elnaghy, Amr Mohamed

    2012-01-01

    The purpose of this study was to investigate the antibacterial activity of calcium hydroxide [Ca(OH)2] combined with chitosan solutions against Enterococcus faecalis-infected root canal dentin and the effect of this new intracanal medicament on the bond strength of RealSeal sealer to radicular dentin. An experimental intracanal medicament was prepared by mixing different concentrations of chitosan solution (25%, 50%, and 100%, W/V) to Ca(OH)2 powder. Antibacterial activity was evaluated and the total numbers of colony forming units were determined. Bonding ability of RealSeal sealer to radicular dentin was evaluated using push-out bond strength test. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey's multiple comparison tests. We found that Ca(OH)2 combined with different concentrations of chitosan solutions showed better antibacterial activity than Ca(OH)2 mixed with saline, without significantly affecting the bond strength of RealSeal sealer to radicular dentin (P > 0.05). The findings suggest that Ca(OH)2 combined with chitosan is a promising intracanal medicament and may be effective in endodontic therapy. PMID:23554749

  14. Pulp response to high fluoride releasing glass ionomer, silver diamine fluoride, and calcium hydroxide used for indirect pulp treatment: An in-vivo comparative study

    PubMed Central

    Korwar, Atish; Sharma, Sidhartha; Logani, Ajay; Shah, Naseem

    2015-01-01

    Aims and Objectives: The study aims at determining pulp response of two high fluoride releasing materials silver diamine fluoride (SDF) and Type VII glass ionomer cement (GIC) when used as indirect pulp treatment (IPT) materials. Materials and Methods: Deep Class V cavities were made on four first premolars indicated for extraction for orthodontic reasons. SDF, Type VII GIC, and calcium hydroxide base are given in three premolars, and one is kept control. Premolars were extracted 6 weeks after the procedure and subjected to histopathological examination to determine the pulp response. The results were analyzed using Chi-square test. Results: No inflammatory changes were observed in any of the groups. Significantly more number of specimens in SDF and Type VII GIC groups showed tertiary dentin deposition (TDD) when compared to control group. No significant difference was seen in TDD when intergroup comparison was made. Odontoblasts were seen as short cuboidal cells with dense basophilic nucleus in SDF and Type VII GIC group. Conclusion: The study demonstrated TDD inducing ability of SDF and Type VII GIC and also established the biocompatibility when used as IPT materials. PMID:26321822

  15. Pulp response to high fluoride releasing glass ionomer, silver diamine fluoride, and calcium hydroxide used for indirect pulp treatment: An in-vivo comparative study.

    PubMed

    Korwar, Atish; Sharma, Sidhartha; Logani, Ajay; Shah, Naseem

    2015-01-01

    The study aims at determining pulp response of two high fluoride releasing materials silver diamine fluoride (SDF) and Type VII glass ionomer cement (GIC) when used as indirect pulp treatment (IPT) materials. Deep Class V cavities were made on four first premolars indicated for extraction for orthodontic reasons. SDF, Type VII GIC, and calcium hydroxide base are given in three premolars, and one is kept control. Premolars were extracted 6 weeks after the procedure and subjected to histopathological examination to determine the pulp response. The results were analyzed using Chi-square test. No inflammatory changes were observed in any of the groups. Significantly more number of specimens in SDF and Type VII GIC groups showed tertiary dentin deposition (TDD) when compared to control group. No significant difference was seen in TDD when intergroup comparison was made. Odontoblasts were seen as short cuboidal cells with dense basophilic nucleus in SDF and Type VII GIC group. The study demonstrated TDD inducing ability of SDF and Type VII GIC and also established the biocompatibility when used as IPT materials.

  16. Comparative evaluation of the antimicrobial activity of natural extracts of Morinda citrifolia, papain and aloe vera (all in gel formulation), 2% chlorhexidine gel and calcium hydroxide, against Enterococcus faecalis: An in vitro study

    PubMed Central

    Bhardwaj, Anuj; Ballal, Suma; Velmurugan, Natanasabapathy

    2012-01-01

    Aim: A comparative evaluation of the antimicrobial activity of natural extracts of Morinda citrifolia, papain, and aloe vera (all in gel formulations), 2% chlorhexidine gel and calcium hydroxide, against Enterococcus faecalis—an in vitro study. Materials and Methods: The antimicrobial efficacy was assessed in vitro using dentin shavings collected at 2 depths of 200 and 400 μm. The total colony forming units at the end of 1, 3, and 5 days were assessed. Results: The overall percentage inhibition of bacterial growth (200 and 400 μm depth) was 100% with chlorhexidine gel. This was followed by M. citrifolia gel (86.02%), which showed better antimicrobial efficacy as compared with aloe vera gel (78.9%), papain gel (67.3%), and calcium hydroxide (64.3%). There was no statistical difference between data at 200 and 400 μm depth. Conclusion: Chlorhexidine gel showed the maximum antimicrobial activity against E. faecalis, whereas calcium hydroxide showed the least. Among the natural intracanal medicaments, M. citrifolia gel consistently exhibited good inhibition up to the 5th day followed by aloe vera gel and papain gel. PMID:22876022

  17. 21 CFR 184.1191 - Calcium carbonate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... soda process”; (2) By precipitation of calcium carbonate from calcium hydroxide in the “Carbonation process”; or (3) By precipitation of calcium carbonate from calcium chloride in the “Calcium...

  18. 21 CFR 184.1191 - Calcium carbonate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... soda process”; (2) By precipitation of calcium carbonate from calcium hydroxide in the “Carbonation process”; or (3) By precipitation of calcium carbonate from calcium chloride in the “Calcium...

  19. 21 CFR 184.1191 - Calcium carbonate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... soda process”; (2) By precipitation of calcium carbonate from calcium hydroxide in the “Carbonation process”; or (3) By precipitation of calcium carbonate from calcium chloride in the “Calcium...

  20. 21 CFR 184.1191 - Calcium carbonate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... soda process”; (2) By precipitation of calcium carbonate from calcium hydroxide in the “Carbonation process”; or (3) By precipitation of calcium carbonate from calcium chloride in the “Calcium...

  1. Calcium

    MedlinePlus

    ... You'll also find calcium in broccoli and dark green, leafy vegetables (especially collard and turnip greens, ... can enjoy good sources of calcium such as dark green, leafy vegetables, broccoli, chickpeas, and calcium-fortified ...

  2. Effectiveness of nano-calcium phosphate paste on sensitivity during and after bleaching: a randomized clinical trial.

    PubMed

    Loguercio, Alessandro Dourado; Tay, Lidia Yileng; Herrera, Daniel Rodrigo; Bauer, Jose; Reis, Alessandra

    2015-01-01

    The study aimed to evaluate the effectiveness of in-office bleaching and associated tooth sensitivity on application of nano-calcium phosphate paste as desensitizing agent. Bleaching was performed with 35% hydrogen peroxide gel in 40 patients who were randomly divided into placebo and nano-calcium phosphate paste groups. Bleaching efficacy (BE) was evaluated using a value-oriented Vita shade guide. Tooth sensitivity was recorded using a numeric rating scale (0-4) during bleaching and up to 48 h after each session. The primary outcome of absolute risk of tooth sensitivity was compared using the Fisher's exact test (α = 0.05). The intensity of tooth sensitivity and the efficacy of in-office bleaching were also statistically evaluated. No significant differences in absolute risk and intensity of tooth sensitivity were detected between the groups (p = 1.0 and p = 0.53, respectively). BE was also found to be similar between the groups (p = 0.67). Although the use of a nano-calcium phosphate paste associated with fluoride and potassium nitrate did not influence the whitening outcome, but it also did not reduce bleaching-induced tooth sensitivity.

  3. Single versus two visits with 1-week intracanal calcium hydroxide medication for endodontic treatment: One-year post-treatment results from a multicentre randomised controlled trial.

    PubMed

    Fonzar, Federica; Mollo, Aniello; Venturi, Mauro; Pini, Pierpaolo; Fabian Fonzar, Riccardo; Trullenque-Eriksson, Anna; Esposito, Marco

    To evaluate whether it is more effective to complete endodontic treatment in a single visit or in two visits with 1-week intracanal calcium hydroxide medication in symptomatic teeth and teeth with periapical lesions. One hundred and ninety-nine patients, with one symptomatic tooth or a tooth with a periapical lesion, were randomised, according to a parallel group design, to receive a complete endodontic treatment in a single visit (99 patients) or in two visits with 1-week intracanal calcium hydroxide medication (100 patients), at two centres. Patients were followed for up to 1 year post-treatment and the outcome measures were tooth loss, radiographic healing, any complication, post-treatment pain and amount of painkillers used. Seven patients dropped out from the single-visit and ten patients from the two-visit group (all patients from one centre only). One patient lost his tooth from the single-visit and two patients from the two-visit group (difference in proportion = -0.01; 95% CI: -0.05 to 0.03; P = 0.619). Five single-visit patients and nine two-visit patients experienced one complication each (difference in proportion = -0.05; 95% CI: -0.12 to 0.03; P = 0.278). There were no statistically significant differences in tooth loss and complications. One year after treatment, complete radiographic healing was observed in 22 patients of the single-visit group and in 19 patients of the two-visit group; improvement in 43 patients of the single-visit group and in 54 patients of the two-visit group; and no changes/worsening in 24 patients of the single-visit group and in 15 patients of the two-visit group. There were no statistically significant differences in radiographic healing between the two groups (P = 0.509). Pre-treatment pain was reported by 68 single-visit patients and by 68 two-visit patients; 1-week post-treatment pain was reported by 27 single-visit patients and by 46 two-visit patients, and 2-week post-treatment pain was reported by 2

  4. NICKEL HYDROXIDES

    SciTech Connect

    MCBREEN,J.

    1997-11-01

    Nickel hydroxides have been used as the active material in the positive electrodes of several alkaline batteries for over a century. These materials continue to attract a lot of attention because of the commercial importance of nickel-cadmium and nickel-metal hydride batteries. This review gives a brief overview of the structure of nickel hydroxide battery electrodes and a more detailed review of the solid state chemistry and electrochemistry of the electrode materials. Emphasis is on work done since 1989.

  5. Comparison of efficiency of ethylenediaminetetraacetic acid, citric acid, and etidronate in the removal of calcium hydroxide intracanal medicament using scanning electron microscopic analysis: An in-vitro study

    PubMed Central

    Chockattu, Sherin Jose; Deepak, B. S.; Goud, K. Mallikarjun

    2017-01-01

    Context: Being integral to root canal therapy, obturation can be performed adequately only after the removal of intracanal medicament. One technique involves the use of chelating agents such as ethylenediaminetetraacetic acid (EDTA) and citric acid. Etidronic acid, a relatively new chelator, has smear layer removal ability and lesser dentinal erosion. It is untested in calcium hydroxide (Ca[OH]2) medicament removal. Aim: The aim of this study was to compare the efficiency of irrigation protocols (EDTA, citric acid, and etidronate) in Ca(OH)2 removal. Materials and Methods: Forty-five single-rooted mandibular premolars were decoronated, instrumented, and filled with Ca(OH)2. After 7 days incubation, Ca(OH)2 was removed by three irrigation protocols (Group-I: 17% EDTA; Group-II: 10% citric acid; and Group-III: 18% etidronate). Roots were split and analyzed (scanning electron microscope, ×1500). Chelator solution pH was tested. Data were analyzed by Kruskal–Wallis ANOVA and Mann–Whitney U-test. Results: Group-III (coronal-third) and Groups-I and II (middle-third) had highest cleanliness scores; Groups-II and III (apical-third) had lowest scores. Comparing the thirds, all groups showed difference in scores. pH of Groups-I, II, and III were 6.8, 1.4, and 0.3, respectively. Conclusion: The solution pH of citric acid and etidronate impacts their Ca(OH)2 removal efficiency in different ways: the highly alkaline pH of Ca(OH)2 increases citric acid pH toward neutrality, where it becomes an inefficient chelator; on the contrary, high acidity of etidronate compensates for its weaker chelation. Etidronate may not require 5 min duration for Ca(OH)2 removal due to the likelihood of dentinal erosion. PMID:28761245

  6. An in vitro comparison of irrigation using photon-initiated photoacoustic streaming, ultrasonic, sonic and needle techniques in removing calcium hydroxide.

    PubMed

    Arslan, H; Akcay, M; Capar, I D; Saygili, G; Gok, T; Ertas, H

    2015-03-01

    To evaluate the effect of various techniques including photon-initiated photoacoustic streaming (PIPS), ultrasonic, sonic and needle irrigation on the removal of calcium hydroxide [Ca(OH)2 ] from artificial grooves created in root canals. The root canals of 48 extracted single-rooted teeth with straight canals were prepared using ProTaper rotary instruments up to size 40. After the specimens had been split longitudinally, a standardized groove was prepared in the apical part of one segment that was filled with Ca(OH)2 powder mixed with distilled water. Each tooth was reassembled and the apices closed with wax. The specimens were irrigated for 60 s with one of the following techniques: needle irrigation using 17% EDTA, PIPS with 17% EDTA, ultrasonic irrigation using 17% EDTA and sonic irrigation (EndoActivator) using 17% EDTA. The root segments were then disassembled, and the amount of remaining Ca(OH)2 evaluated under a stereomicroscope at 25× magnification. A pixel count of Ca(OH)2 remaining on the artificially created grooves was recorded as a percentage of the overall groove surface. The data were evaluated statistically using one-way analysis of variance and the least significant difference post hoc tests at 95% confidence level (P = 0.05). Photon-initiated photoacoustic streaming was superior in removing Ca(OH)2 as compared to needle irrigation (P < 0.001), sonic irrigation (P < 0.001) and ultrasonic irrigation (P = 0.046). Photon-initiated photoacoustic streaming provided complete removal of Ca(OH)2 from artificial grooves in straight root canals. Ultrasonic irrigation enhanced the Ca(OH)2 removal capacity of irrigating solution but did not provide complete removal from artificial grooves. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  7. Ultrasonically Activated Irrigation to Remove Calcium Hydroxide from Apical Third of Human Root Canal System: A Systematic Review of In Vitro Studies.

    PubMed

    Ethem Yaylali, Ibrahim; Kececi, Ayse Diljin; Ureyen Kaya, Buglem

    2015-10-01

    The aim of this systematic review was to summarize the outcomes of in vitro studies comparing ultrasonically activated irrigation versus other irrigation techniques for removing calcium hydroxide (Ca[OH]2) from the apical third of root canals. The research question was developed according to the PICO strategy. A comprehensive literature search was performed. The Medline, Embase, and TRIP electronic databases were searched. A hand search of the reference lists of identified articles was performed to isolate relevant articles. Two reviewers critically assessed the studies against our inclusion and exclusion criteria. Evaluation of the risk of bias of the studies was performed independently by the 2 reviewers. After study selection, 62 were assessed for eligibility. Of these, 9 met the inclusion criteria and were included in the systematic review. Because considerable heterogeneity was found in the methodologies, it was not possible to combine the results of studies in a meta-analysis. Ultrasonically activated irrigation was found to be superior to syringe irrigation and apical negative pressure irrigation, but insufficient evidence was found to indicate its superiority over the other irrigation techniques such as sonically activated irrigation, the Self-Adjusting File, (ReDent-Nova, Ra'anana, Israel) and the RinsEndo, (Dürr Dental, Bietigheim, Germany). On the basis of available evidence, we determined the effectiveness of ultrasonically activated irrigation compared with syringe and apical negative pressure irrigation. Because of the small sample sizes, low number of included studies, and limitations, further research is needed to confirm our results. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  8. Management of Cyst-like Periapical Lesions by Orthograde Decompression and Long-term Calcium Hydroxide/Chlorhexidine Intracanal Dressing: A Case Series.

    PubMed

    Santos Soares, Suelleng Maria Cunha; Brito-Júnior, Manoel; de Souza, Flávia Kelly; Zastrow, Eduardo Von; Cunha, Carla Oliveira da; Silveira, Frank Ferreira; Nunes, Eduardo; César, Carlos Augusto Santos; Glória, José Cristiano Ramos; Soares, Janir Alves

    2016-07-01

    Cyst-like periapical lesions should be treated initially with conservative nonsurgical procedures. In this case series, we describe the clinical and radiographic outcomes of large cyst-like lesions that were treated by orthograde decompression and long-term intracanal use of calcium hydroxide [Ca(OH)2] mixed with 2% chlorhexidine digluconate. Ten cases of cyst-like periapical lesions involving 15 teeth from 10 patients were selected. Maximal radiographic diameters of the lesions ranged from 11 to 28 mm. Nonsurgical procedures were performed, including apical patency, orthograde puncture of cyst-like exudates, chemomechanical preparation, and placement of intracanal Ca(OH)2/CHX dressings, which were periodically replaced during 6-10 months. The root canals were then filled with gutta-percha and sealer. The follow-up periods ranged from 6 to 24 months, and the outcome was classified as healed, healing, or failure. Nine lesions drained copious exudates after canal patency. One lesion only drained bloody serous exudate after periapical overinstrumentation. In 9 patients, intracanal exudation ceased in the first follow-up visit. At the 24-month follow-up, 6 lesions (60.0%) had healed, and 3 lesions (30.0%) were healing, with the corresponding patients being without clinical signs or symptoms. The case of treatment failure was submitted to surgical treatment. Microscopically, the lesion appeared to be an apical cyst with exuberant extraradicular bacterial biofilms attached to the sectioned root apex. This case series supports the use of nonsurgical methods to resolve larger cyst-like periapical lesions. Published by Elsevier Inc.

  9. Counteraction of reactive oxygen species and determination of antibacterial efficacy of proanthocyanidin and lycopene when mixed with calcium hydroxide and chlorhexidine mixture: An in vitro comparative study

    PubMed Central

    Mageshwaran, TA; Ebenezar, AV Rajesh; Madhanamadhubala, M; Kavitha, S; Mahalaxmi, S

    2012-01-01

    Aim: The objective of the study was to determine the neutralizing effect of proanthocyanidin (grape seed extract) and lycopene (tomato extract) on reactive oxygen species (ROS) generated by the mixture when used as an intracanal medicament. The study also evaluated the effect of proanthocyanidin and lycopene on the antibacterial efficacy of a mixture of chlorhexidine (CHX) and calcium hydroxide [Ca(OH)2] against Enterococcus feacalis. Materials and Methods: Four sample groups were prepared as follows. Group I: 2% CHX gluconate (control group) and group II: a mixture of 125 mg of Ca(OH)2 with 2% CHX gluconate solution. Group III was a mixture of 125 mg of Ca(OH)2 with 1 mL of 2% CHX gluconate solution and 1 mL of 5% proanthocyanidin solution and group IV, a mixture of 125 mg of Ca(OH)2 with 1 mL of 2% CHX gluconate solution and 1 mL of 5% lycopene solution. The groups were analyzed for ROS formation using the mass spectrometer (JEOL GC MATE II) immediately after preparation. The antibacterial property was evaluated by using agar diffusion method and the results were statistically analyzed using one-way analysis of variance (ANOVA) and Tukey-Kramer multiple comparison tests. Results: The peak value of 196.96 denotes ROS formation. Group II shows a higher peak value than other groups. Group IV shows a drastic reduction in the peak value. Group IV shows a drastic reduction in ROS formation when compared with group II, group III, and the control group. Antibacterial efficacy was higher in group IV, followed by group III, group II, and group I. Conclusion: Lycopene and proanthocyanidin reduce the ROS significantly by virtue of their antioxidant property. Lycopene shows more antioxidant property when compared with proanthocyanidin. PMID:23112480

  10. Comparison of calcium hydroxide removal by self-adjusting file, EndoVac, and CanalBrush agitation techniques: An in vitro study

    PubMed Central

    Türker, Sevinç Aktemur; Koçak, Mustafa Murat; Koçak, Sibel; Sağlam, Baran Can

    2013-01-01

    Objectives: This study comparatively evaluated the efficacy of self-adjusting file (SAF), Endovac, and CanalBrush irrigant agitation protocols in removing calcium hydroxide (Ca(OH)2) from the root canals. Materials and Methods: Sixty extracted human mandibular canine teeth were instrumented with ProTaper rotary instruments to size #40 and dressed with Ca(OH)2. The roots were randomly assigned to four groups according to irrigant agitation protocol used (n = 15). In Group 1: Conventional syringe irrigation (no activation, control); Group 2: Rotary brush agitation (CanalBrush); Group 3: Apical negative pressure irrigation (EndoVac system); and Group 4: Sonic agitation (SAF) were used. Scanning electron microscopic (SEM) evaluation was done for assessment of Ca(OH)2 removal in the coronal and apical thirds. Statistical analysis was performed by Wilcoxon and Kruskal-Wallis tests. Results: There were statistically significant differences among the groups (P = 0.218). A statistically significant difference was seen between the test groups in Ca(OH)2 removal from the apical third of the canal (P < 0.05). In the coronal third, there was no difference between the groups (P > 0.05). The most efficient Ca(OH)2 removal in apical third was recorded in Group 3 (EndoVac) and Group 4 (SAF) (P < 0.05). In Group 4 (sonic agitation), there was no significantly difference between Ca(OH)2 removal in coronal and apical thirds. Conclusions: SAF and EndoVac showed significantly better performance than CanalBrush and conventional syringe irrigation in removing Ca(OH)2 from apical third of the root canals. PMID:24082574

  11. Effect of Calcium Hydroxide Based Intracanal Medicaments on the Apical Sealing Ability of Resin Based Sealer and Guttapercha Obturated Root Canals

    PubMed Central

    Sumanthini, MV; Shenoy, Vanitha U; Bodhwani, Mohit A

    2017-01-01

    Introduction Calcium Hydroxide (CH) is one of the most commonly used intracanal medicaments which can be used with various vehicles. Aim The aim of this in vitro study was to evaluate the effect of three CH based intracanal medicaments on the apical sealing ability of AH Plus – guttapercha obturation. Materials and Methods Crowns of 100 extracted single rooted human teeth were sectioned at the Cemento-Enamel Junction (CEJ) to a standardized length. The root canals were instrumented upto ISO size 40 using step back technique and the specimens were randomly divided into two control and four experimental groups. The control groups were not medicated. Specimens in positive control group (Group I) were obturated with guttapercha without placing sealer and in negative control group (Group II) were obturated with guttapercha and AH Plus sealer. Among the experimental groups, specimens of Group III were not medicated while groups IV, V and VI were medicated with CH-saline, CH-2% Chlorhexidine (CHX) and Vitapex respectively for a period of 14 days. The medicaments were removed from the specimens and the teeth were obturated with AH Plus sealer and guttapercha using lateral compaction technique. The specimens were immersed in India ink dye, demineralized and diphanized. The extent of dye penetration was assessed using a 10X stereomicroscope. Data obtained was statistically analyzed by one-way ANOVA (p<0.05) followed by Post-hoc Tukey test. Results Amongst the three CH medicaments, CH-2% CHX when used as an intracanal medicament showed a significantly higher microleakage as compared to the other groups with p<0.001. The microleakage values between the remaining groups were not statistically significant. Conclusion Under the conditions of this study it was concluded that all groups with or without intracanal medicament showed apical leakage. The vehicle used to carry CH may significantly influence the apical sealing ability of guttapercha – AH Plus obturated canals. PMID

  12. The effect of frequency of calcium hydroxide dressing change and various pre- and inter-operative factors on the endodontic treatment of traumatized immature permanent incisors.

    PubMed

    Yassen, Ghaeth H; Chin, Judith; Mohammedsharif, Ahmed G; Alsoufy, Saif S; Othman, Samer S; Eckert, George

    2012-08-01

    The objectives of this clinical study were as follows: (i) to determine the effect of frequency of calcium hydroxide [Ca(OH)(2)] dressing change on the apical barrier formation in immature permanent incisors with necrotic pulps and (ii) to investigate the effect of various clinical factors before and during treatment that may be associated with the frequency of Ca(OH)(2) dressing changes. The study involved 21 healthy subjects, 8-12 years old. Twenty-three immature traumatized permanent maxillary central incisors were treated using Ca(OH)(2) powder mixed with barium sulfate and distilled water. The progress of barrier formation was reviewed after 6 months of first placement of Ca(OH)(2) and then every 3 months until the detection of an apical barrier. Clinical and radiographic evaluations were performed before and after treatment. Data were evaluated using a chi-square test. Apical barrier formation was successful for all 23 teeth. Seventeen teeth (74%) needed only a single application of Ca(OH)(2), while six teeth (26%) required more than one application. The average time of apical barrier formation was 30 weeks, and the mean number of Ca(OH)(2) dressing changes was 1.3. A significant positive association was found between teeth that presented with displacement and the number of Ca(OH)(2) dressing changes (P = 0.004). An initial 6-month application of Ca(OH)(2) dressing followed by 3-month replacements (usually in teeth presenting with displacement and/or sinus tracts) may be successfully used in apexification treatment. This would assist in reducing the number of Ca(OH)(2) dressing changes, number of appointments, cost of treatment and radiation exposure. © 2011 John Wiley & Sons A/S.

  13. Quantitative comparison of calcium hydroxide removal by EndoActivator, ultrasonic and ProTaper file agitation techniques: an in vitro study.

    PubMed

    Khaleel, Huda Yasir; Al-Ashaw, Ahmed Jawad; Yang, Yan; Pang, Ai-hui; Ma, Jing-zhi

    2013-02-01

    Calcium hydroxide (CH) dressing residues can compromise endodontic sealing. This study aimed to evaluate the amount of remaining CH in root canals after mechanical removal by four groups of irrigation techniques including needle irrigation only, ProTaper file, EndoActivator, and ultrasonic file. Fifteen extracted single-rooted teeth were collected and used for all four groups. The samples were firstly prepared by ProTaper rotary instruments, and then sectioned longitudinally through the long axis of the root canals, followed by final reassembling by wires. CH was kept in the canals for 7 days setting. The removal procedure began with 5 mL of 2.5% sodium hypochlorite (NaOCl) followed by 1 mL of 17% ethylenediaminetetraacetic acid and a final irrigation with 5 mL of 2.5% NaOCl solution for all groups. No additional agitation of the irrigant was performed in group 1, while agitation for 20 s between irrigants was done with F2 ProTaper rotary file in group 2, EndoActivator with tip size 25/.04 in group 3 and by an ultrasonic file 25/.02 in group 4. The total activation time was 60 s. The roots were then disassembled and captured by digital camera. The ratio of CH coated surface area to the surface area of the whole canal as well as each third of the canal was calculated. The data were statistically analyzed by one-way ANOVA using post hoc Tukey test. Results showed that none of the four techniques could remove all CH. No significant difference was found between EndoActivator and ultrasonic techniques. However, they both removed significantly more CH than ProTaper and needle irrigation (P=0.0001). In conclusion, the sonic and ultrasonic agitation techniques were more effective in removing intracanal medicaments than the ProTaper rotary file and needle irrigation in all thirds of the canal.

  14. Pulpal responses to bacterial contamination following dentin bridging beneath hard-setting calcium hydroxide and self-etching adhesive resin system.

    PubMed

    Kitasako, Yuichi; Ikeda, Masaomi; Tagami, Junji

    2008-04-01

    To evaluate the pulp healing to bacterial contamination beneath a hard-setting calcium hydroxide (DY: Dycal, L.D. Caulk Co.) and a self-etching adhesive resin (2V: Clearfil Liner Bond 2V, Kuraray Medical Inc.) following dentin bridge formation. Class V cavities were prepared on 30 monkey teeth, and the pulps were exposed with a carbide bur through the cavity floor. Each exposed pulp was capped with either DY or 2V. The cavities were restored with a hybrid resin composite. The resin composite was removed at 180 days after capping, and then cavities were left open to the oral environment for 2 weeks to obtain bacteria contamination DY (BDY) and 2V (B2V; n = 10). A non-bacterial-contaminated group capped with DY was used as control. After bacterial challenges, inflammatory cell infiltration, incidence and differentiation of dentin bridges were evaluated histologically. There were significant differences in the presence of inflammatory cell infiltration among all groups (P < 0.05). No moderate or severe inflammatory reaction was found in Group DY. Group BDY showed moderate or severe inflammatory cell infiltration in 50%, and showed four necrotic specimens. Although no statistically significant difference was found in the formation and differentiation of dentin bridges among all groups, tunnel defects in dentin bridges were detected in 70% (DY), 80% (BDY), and 50% (B2V). Group B2V showed a significantly lower presence of inflammatory cell infiltration than Group BDY (P < 0.05). Bonding agent is supposed to seal the exposure site, and the remaining bonding agent on the cavities was effective as the barrier in the dentin bridges after bacterial challenges.

  15. Comparative evaluation of platelet-rich fibrin, mineral trioxide aggregate, and calcium hydroxide as pulpotomy agents in permanent molars with irreversible pulpitis: A randomized controlled trial

    PubMed Central

    Kumar, Varun; Juneja, Ruchi; Duhan, Jigyasa; Sangwan, Pankaj; Tewari, Sanjay

    2016-01-01

    Background: Pulpotomy has been proposed as an alternative for the management of irreversible pulpitis in permanent molars with closed apices. Aim: To compare the performances of calcium hydroxide (CH), mineral trioxide aggregate (MTA), and platelet-rich fibrin (PRF) as pulpotomy agents in mature permanent molars with irreversible pulpitis. Materials and Methods: Fifty-four permanent mandibular molars with carious exposure and symptoms of irreversible pulpitis were randomly allocated to three groups, and full pulpotomy was performed using CH, MTA, or PRF as pulpotomy agents. Pain intensity was recorded using numeric rating scale score at baseline, 24 h, 7 days, 6 months, and 1 year. Clinical and radiographic assessments were done at 6 months and 1 year. Statistical Analysis: Kruskal–Wallis test and Friedman test were used for intergroup and intragroup comparison of pain scores, respectively. The radiographic outcomes between the three study arms were compared using Chi-square test. Results: Clinical success rate was 94.4% at 7 days, which dropped to 85.4% at 12 months. All three agents were equally effective in providing pain relief at all the intervals tested, with no significant difference between them (P > 0.05 at all intervals). However, at 6 months and 12 months, 26.2% and 52.4% teeth depicted slight widening of periodontal ligament space. No significant difference was observed between the radiographic success rates observed with the three groups (P = 0.135 at 6 months, 0.717 at 12 months). Conclusion: Pulpotomy exhibited a high clinical success rate in mature molars with irreversible pulpitis and selection of biomaterial did not affect its outcome. PMID:27994420

  16. Influence of powder composition and morphology on penetration of gray and white ProRoot mineral trioxide aggregate and calcium hydroxide into dentin tubules

    PubMed Central

    Komabayashi, Takashi; Long, Leann; Ahn, Chul; Spears, Robert; Zhu, Qiang; Eberhart, Robert C.

    2015-01-01

    This study examined the influence of powder composition and morphology on the penetration of Gray and White ProRoot mineral trioxide aggregate (GMTA, WMTA) and calcium hydroxide (CH) into open dentin tubules. GMTA, WMTA, and CH particle dimensions were analyzed by flow particle image analysis (FPIA). Penetration of open dentin tubules into dentin discs was studied by scanning electron microscopy. Five samples of each material were randomly selected and prepared for this study. The GMTA averages for length (μm), width (μm), perimeter (μm), and aspect ratio were 1.94 ± 1.65, 1.43 ± 1.19, 5.61 ± 4.27, and 0.76 ± 0.14, respectively. Corresponding averages for WMTA were 2.04 ± 1.87, 1.49 ± 1.33, 5.88 ± 4.81, and 0.76 ± 0.14, and for CH were 2.26 ± 1.99, 1.62 ± 1.46, 6.70 ± 5.60, and 0.74 ± 0.15, respectively. The rank order of the averages for particle length, width and perimeter from the largest to the smallest material was CH > WMTA > GMTA. The rank order of the averaged aspect ratios was GMTA > WMTA > CH. SEM showed that all three materials, when deposited and agitated on dentin discs, penetrated the open dentin tubules. Tubule occlusion occurred as particle surface concentrations increased. Significant differences in particle length, width, perimeter, and aspect ratio were observed for GMTA, WMTA, and CH (P < 0.0001 in all cases). All particle types penetrated into open tubules when agitated on dentin discs; all tubules were eventually occluded as particle concentrations grew. PMID:25500926

  17. [Effect of adhesive composite resin on pulp and capping of pulp with calcium hydroxide base (Dycal) in deciduous teeth of young dogs].

    PubMed

    Yamada, S; Nozaka, K; Amari, E

    1990-01-01

    This study was designed to investigate the effect of adhesive composite resin (Clearfil SC Bond) on dental pulp and the effect of calcium hydroxide base (Dycal) on the protection of the pulp, using 66 deciduous teeth of young dogs. After forming a cavity (class 5) on the labial aspect in each tooth, the teeth were divided by the modes of plugging into 4 groups; stopping alone (Group S), stopping and capping with Dycal (Group D+S), capping with Dycal and resin (Group D+R) and capping with resin alone (Group R). After decalcification, the specimen was embedded in celloidin, sliced into thin sections and stained with hematoxylin and eosin for histopathological examination. Histological changes were examined at 3 days, 1 week, 2 weeks and 4 weeks. The following are the results obtained. 1. In Group S, slight histological changes were observed at 3 days and 1 week. However, the changes began to diminish after the 2nd week and disappeared in the 4th week. 2. In Group R, the severest histological changes persisted throughout the course of observation. The changes were not diminished even in the 4th week. Thus, the resin seemed to exert a strong and long-lasting stimulative effect against the pulp. 3. In Group D+S and D+R, the histological changes were more serve at 3 days and 1 week compared to those found in Group S, but these were diminished after the 2nd week. This seemed to suggest that the pulp was stimulated to a certain degree by Dycal but also, Dycal protected the pulp from stimulation of the resin. 4. Capping of the pulp seemed necessary in vital teeth with resin restoration.

  18. Influence of powder composition and morphology on penetration of Gray and White ProRoot mineral trioxide aggregate and calcium hydroxide into dentin tubules.

    PubMed

    Komabayashi, Takashi; Long, Leann; Ahn, Chul; Spears, Robert; Zhu, Qiang; C Eberhart, Robert

    2014-12-01

    This study examined the influence of powder composition and morphology on the penetration of Gray and White ProRoot mineral trioxide aggregate (GMTA, WMTA) and calcium hydroxide (CH) into open dentin tubules. GMTA, WMTA, and CH particle dimensions were analyzed by flow particle image analysis (FPIA). Penetration of open dentin tubules into dentin discs was studied by scanning electron microscopy. Five samples of each material were randomly selected and prepared for this study. The GMTA averages for length (μm), width (μm), perimeter (μm), and aspect ratio were 1.94 ± 1.65, 1.43 ± 1.19, 5.61 ± 4.27, and 0.76 ± 0.14, respectively. Corresponding averages for WMTA were 2.04 ± 1.87, 1.49 ± 1.33, 5.88 ± 4.81, and 0.76 ± 0.14, and for CH were 2.26 ± 1.99, 1.62 ± 1.46, 6.70 ± 5.60, and 0.74 ± 0.15, respectively. The rank order of the averages for particle length, width and perimeter from the largest to the smallest material was CH > WMTA > GMTA. The rank order of the averaged aspect ratios was GMTA > WMTA > CH. SEM showed that all three materials, when deposited and agitated on dentin discs, penetrated the open dentin tubules. Tubule occlusion occurred as particle surface concentrations increased. Significant differences in particle length, width, perimeter, and aspect ratio were observed for GMTA, WMTA, and CH (P < 0.0001 in all cases). All particle types penetrated into open tubules when agitated on dentin discs; all tubules were eventually occluded as particle concentrations grew. (J Oral Sci 56, 287-293, 2014).

  19. Time-dependent antibacterial effects of Aloe vera and Zataria multiflora plant essential oils compared to calcium hydroxide in teeth infected with Enterococcus faecalis.

    PubMed

    Abbaszadegan, Abbas; Sahebi, Safoora; Gholami, Ahmad; Delroba, Alireza; Kiani, Amin; Iraji, Aida; Abbott, Paul Vincent

    2016-02-01

    In the present in vitro study, we investigated the time-related antimicrobial efficacy of Aloe vera and Zataria multiflora (Z. multiflora) plant essential oils compared to calcium hydroxide ([Ca[OH]2 ) to eliminate Enterococcus faecalis (E. faecalis) from root canals. A new strain of E. faecalis (Enterococcus spp. AGH04) was isolated from a previously root-filled tooth with persistent apical periodontitis. The 16S rRNA sequence was analyzed and deposited in GeneBank under accession number KF465681. A total of 108 extracted human single-rooted teeth were contaminated with this bacterial strain and treated with Aloe vera essential oil, Z. multiflora essential oil, and Ca(OH)2 for 1, 7, and 14 days. Gas chromatography-mass spectrometry (GC-MS) was used to determine the chemical composition of the oils. The percentage reduction from initial c.f.u./mL counts were calculated and analyzed. Carvacrol, thymol, and linalool were the main constituents of both essential oils. The c.f.u./mL count reductions significantly increased for all three medicaments when the contact time was extended. A statistically-significant difference was observed between the medicaments after 1 and 7 days, but there was no significant difference after 14 days. Both medicinal herbs showed equal antimicrobial efficiency against E. faecalis, comparable to Ca(OH)2 for the prolonged contact time of 14 days. © 2014 Wiley Publishing Asia Pty Ltd.

  20. A self-setting iPSMSC-alginate-calcium phosphate paste for bone tissue engineering

    PubMed Central

    Wang, Ping; Song, Yang; Weir, Michael D.; Sun, Jinyu; Zhao, Liang; Simon, Carl G.; Xu, Hockin H. K.

    2015-01-01

    Objectives Calcium phosphate cements (CPCs) are promising for dental and craniofacial repairs. The objectives of this study were to: (1) develop an injectable cell delivery system based on encapsulation of induced pluripotent stem cell-derived mesenchymal stem cells (iPSMSCs) in microbeads; (2) develop a novel tissue engineered construct by dispersing iPSMSC-microbeads in CPC to investigate bone regeneration in an animal model for the first time. Methods iPSMSCs were pre-osteoinduced for 2 weeks (OS-iPSMSCs), or transduced with bone morphogenetic protein-2 (BMP2-iPSMSCs). Cells were encapsulated in fast-degradable alginate microbeads. Microbeads were mixed with CPC paste and filled into cranial defects in nude rats. Four groups were tested: (1) CPC-microbeads without cells (CPC control); (2) CPC-microbeads-iPSMSCs (CPC-iPSMSCs); (3) CPC-microbeads-OS-iPSMSCs (CPC-OS-iPSMSCs); (4) CPC-microbeads-BMP2-iPSMSCs (CPC-BMP2-iPSMSCs). Results Cells maintained good viability inside microbeads after injection. The microbeads were able to release the cells which had more than 10-fold increase in live cell density from 1 to 14 days. The cells exhibited up-regulation of osteogenic markers and deposition of minerals. In vivo, new bone area fraction (mean ± SD; n = 5) for CPC-iPSMSCs group was (22.5 ± 7.6)%. New bone area fractions were (38.9 ± 18.4)% and (44.7 ± 22.8)% for CPC-OS-iPSMSCs group and CPC-BMP2-iPSMSCs group, respectively, 2–3 times the (15.6 ± 11.2)% in CPC control at 12 weeks (p < 0.05). Cell-CPC constructs accelerated scaffold resorption, with CPC-BMP2-iPSMSCs having remaining scaffold material that was 7-fold less than CPC control. Significance Novel injectable CPC-microbead-cell constructs promoted bone regeneration, with OS-iPSMSCs and BMP2-iPSMSCs having 2–3 fold the new bone of CPC control. Cell delivery accelerated scaffold resorption, with CPC-BMP2-iPSMSC having remaining scaffold material that was 7-fold less than CPC control. Therefore, CPC

  1. The Retentive Strength of Cemented Zirconium Oxide Crowns after Dentin Pretreatment with Desensitizing Paste Containing 8% Arginine and Calcium Carbonate

    PubMed Central

    Pilo, Raphael; Harel, Noga; Nissan, Joseph; Levartovsky, Shifra

    2016-01-01

    The effect of dentin pretreatment with Desensitizing Paste containing 8% arginine and calcium carbonate on the retention of zirconium oxide (Y-TZP) crowns was tested. Forty molar teeth were mounted and prepared using a standardized protocol. Y-TZP crowns were produced using computer-aided design and computer-aided manufacturing (CAD-CAM) technology. The 40 prepared teeth were either pretreated with Desensitizing Paste or not pretreated. After two weeks, each group was subdivided into two groups, cemented with either Resin Modified Glass Ionomer Cement (RMGIC) or Self Adhesive Resin Cement (SARC)). Prior to cementation, the surface areas of the prepared teeth were measured. After aging, the cemented crown-tooth assemblies were tested for retentive strength using a universal testing machine. The debonded surfaces of the teeth and crowns were examined microscopically at 10× magnification. Pretreating the dentin surfaces with Desensitizing Paste prior to cementation did not affect the retention of the Y-TZP crowns. The retentive values for RMGIC (3.04 ± 0.77 MPa) were significantly higher than those for SARC (2.28 ± 0.58 MPa). The predominant failure modes for the RMGIC and SARC were adhesive cement-dentin and adhesive cement-crown, respectively. An 8.0% arginine and calcium carbonate in-office desensitizing paste can be safely used to reduce post-cementation sensitivity without reducing the retentive strength of Y-TZP crowns. PMID:27023532

  2. The Retentive Strength of Cemented Zirconium Oxide Crowns after Dentin Pretreatment with Desensitizing Paste Containing 8% Arginine and Calcium Carbonate.

    PubMed

    Pilo, Raphael; Harel, Noga; Nissan, Joseph; Levartovsky, Shifra

    2016-03-25

    The effect of dentin pretreatment with Desensitizing Paste containing 8% arginine and calcium carbonate on the retention of zirconium oxide (Y-TZP) crowns was tested. Forty molar teeth were mounted and prepared using a standardized protocol. Y-TZP crowns were produced using computer-aided design and computer-aided manufacturing (CAD-CAM) technology. The 40 prepared teeth were either pretreated with Desensitizing Paste or not pretreated. After two weeks, each group was subdivided into two groups, cemented with either Resin Modified Glass Ionomer Cement (RMGIC) or Self Adhesive Resin Cement (SARC)). Prior to cementation, the surface areas of the prepared teeth were measured. After aging, the cemented crown-tooth assemblies were tested for retentive strength using a universal testing machine. The debonded surfaces of the teeth and crowns were examined microscopically at 10× magnification. Pretreating the dentin surfaces with Desensitizing Paste prior to cementation did not affect the retention of the Y-TZP crowns. The retentive values for RMGIC (3.04 ± 0.77 MPa) were significantly higher than those for SARC (2.28 ± 0.58 MPa). The predominant failure modes for the RMGIC and SARC were adhesive cement-dentin and adhesive cement-crown, respectively. An 8.0% arginine and calcium carbonate in-office desensitizing paste can be safely used to reduce post-cementation sensitivity without reducing the retentive strength of Y-TZP crowns.

  3. Characterization of high-calcium fly ash and its influence on ettringite formation in portland cement pastes

    NASA Astrophysics Data System (ADS)

    Tishmack, Jody Kathleen

    High-calcium Class C fly ashes derived from Powder River Basin coal are currently used as supplementary cementing materials in portland cement concrete. These fly ashes tend to contain significant amounts of sulfur, calcium, and aluminum, thus they are potential sources of ettringite. Characterization of six high-calcium fly ashes originating from Powder River Basin coal have been carried out. The hydration products formed in pastes made from fly ash and water were investigated. The principal phases produced at room temperature were ettringite, monosulfate, and stratlingite. The relative amounts formed varied with the specific fly ash. Removal of the soluble crystalline sulfur bearing minerals indicated that approximately a third of the sulfur is located in the fly ash glass. Pore solution analyses indicated that sulfur concentrations increased at later ages. Three fly ashes were selected for further study based on their ability to form ettringite. Portland cement-fly ash pastes made with the selected fly ashes were investigated to evaluate ettringite and monosulfate formation. Each of the fly ashes were mixed with four different types of portland cements (Type I, I/II, II, and III) as well as three different Type I cements exhibiting a range of C3A and sulfate contents. The pastes had 25% or 35% fly ash by total weight of solids and a water:cement-fly ash ratio of 0.45. The samples were placed in a curing room (R.H. = 100, 23°C) and were then analyzed at various ages by x-ray diffraction (XRD) and differential scanning calorimetry (DSC) to determine the principal hydration products. The hydration products identified by XRD were portlandite, ettringite (an AFt phase), monosulfate, and generally smaller amounts of hemicarboaluminate and monocarboaluminate (all AFm phases). Although the amount of ettringite formed varied with the individual cement, only a modest correlation with cement sulfate content and no correlation with cement C3A content was observed. DSC

  4. Calcium

    MedlinePlus

    ... in luck if you like sardines and canned salmon with bones. Almond milk. previous continue Working Calcium ... drinks, and cereals. Other Considerations for Building Bones Vitamin D is essential for calcium absorption, so it's ...

  5. Influence of calcium compounds on the mechanical properties of fly ash geopolymer pastes.

    PubMed

    Temuujin, J; van Riessen, A; Williams, R

    2009-08-15

    The influence of calcium compounds (CaO and Ca(OH)(2)) on the mechanical properties of fly ash based geopolymers has been studied. Calcium compounds were substituted in fly ash at 1, 2 and 3 wt%, respectively. Curing of the geopolymers was performed at ambient temperature (20 degrees C) and 70 degrees C. Addition of calcium compounds as a fly ash substitute improved mechanical properties for the ambient temperature cured samples while decreasing properties for the 70 degrees C cured samples. Seven days compressive strength of the ambient temperature cured samples increased from 11.8 (2.9) to 22.8 (3.8)MPa and 29.2 (1.1)MPa for 3% CaO and 3% Ca(OH)(2) additions, respectively.

  6. Preparation of hydroxyapatite/collagen injectable bone paste with an anti-washout property utilizing sodium alginate. Part 1: influences of excess supplementation of calcium compounds.

    PubMed

    Sato, Taira; Kikuchi, Masanori; Aizawa, Mamoru

    2017-03-01

    The anti-washout property, viscosity, and cytocompatibility to an osteoblastic cell line, MG-63, of anti-washout pastes were investigated. Mixing a hydroxyapatite/collagen bone-like nanocomposite (HAp/Col), an aqueous solution of sodium alginate (Na-Alg), which is a paste hardening and lubricant agent, and supplementation of calcium carbonate or calcium citrate (Ca-Cit) as a calcium resource for the hardening reaction realized an injectable bone paste. Adding Ca-Cit at a concentration greater than eight times the Ca(2+) ion concentration to Na-Alg improved the anti-washout property. Although the viscosity test indicated a gradual increase in the paste viscosity as the calcium compounds increased, pastes with excess supplementation of calcium compounds exhibited injectability through a syringe with a 1.8 mm inner diameter, realizing an injectable bone filler. Furthermore, the anti-washout pastes with Ca-Cit had almost the same cell proliferation rate as that of the HAp/Col dense body. Therefore, HAp/Col injectable anti-washout pastes composed of the HAp/Col, Na-Alg, and Ca-Cit are potential candidates for bioresorbable bone filler pastes.

  7. Calcium

    MedlinePlus

    ... such as canned sardines and salmon Calcium-enriched foods such as breakfast cereals, fruit juices, soy and rice drinks, and tofu. Check the product labels. The exact amount of calcium you need depends on your age and other factors. Growing children and teenagers need more calcium than ...

  8. Effect of different final irrigation methods on the removal of calcium hydroxide from an artificial standardized groove in the apical third of root canals.

    PubMed

    Capar, Ismail Davut; Ozcan, Erhan; Arslan, Hakan; Ertas, Huseyin; Aydinbelge, Hale Ari

    2014-03-01

    The aim of this study was to compare the efficacy of conventional syringe, ultrasonic, EndoVac (Discus Dental, Culver City, CA), and Self-Adjusting File (SAF) (Re-Dent-Nova, Ra'nana, Israel) irrigation systems in removing calcium hydroxide (Ca[OH]2) from simulated root canal irregularities. The root canals of 88 extracted single-rooted teeth were prepared using ProTaper rotary instruments (Dentsply Maillefer, Ballagiues, Switzerland) up to size F4. The roots were split longitudinally, and a standardized groove was prepared in the apical part of 1 segment. The root halves were reassembled, and Ca(OH)2 medicament was placed into the root canals using a Lentulo spiral. The roots were randomly divided into 4 experimental groups and 2 control groups according to the different irrigation systems used: conventional syringe irrigation, continuous passive ultrasonic irrigation (PUI), EndoVac irrigation, and SAF irrigation. Each group was then divided into 2 subgroups (n = 10) according to the irrigation protocol: subgroup 1: 10 mL 2.5% NaOCl and subgroup 2: 10 mL 17% EDTA + 10 mL 2.5% NaOCl. The amount of remaining medicament was evaluated under a stereomicroscope at 30× magnification using a 4-grade scoring system. The influences of the different Ca(OH)2 medicament removal methods and irrigation protocols were statistically evaluated using 2-way analysis of variance and Tukey post hoc tests. In the NaOCl-irrigated groups, PUI removed significantly more Ca(OH)2 medicament than the other techniques (P < .05). There was no significant difference among the other groups (P > .05). In the EDTA/NaOCl-irrigated groups, the SAF and PUI removed significantly more Ca(OH)2 than the other techniques (P < .05). The use of the SAF system with the combination of EDTA and NaOCl enhanced Ca(OH)2 removal when compared with the use of only NaOCl irrigation with the SAF. Continuous PUI and SAF were more effective than EndoVac, and conventional syringe irrigation in the removal of the Ca(OH)2

  9. The use of light/chemically hardened polymethylmethacrylate, polyhydroxyethylmethacrylate, and calcium hydroxide graft material in combination with polyanhydride around implants in minipigs: part I: immediate stability and function.

    PubMed

    Hasturk, Hatice; Kantarci, Alpdogan; Ghattas, Mazen; Schmidt, Marcella; Giordano, Russell A; Ashman, Arthur; Diekwisch, Thomas G; Van Dyke, Thomas

    2011-09-01

    The present study is designed as a proof-of-concept study to evaluate light/chemical hardening technology and a newly formulated polymethylmethacrylate, polyhydroxyethylmethacrylate, and calcium hydroxide (PPCH) plus polyanhydride (PA) (PPCH-PA) composite graft material as a bone substitute compared to positive and negative controls in a minipig model. PPCH-PA (composite graft); PPCH alone (positive control), PA alone (positive control), and no graft (negative control) were compared. Four mandibular premolar teeth per quadrant were extracted; a total of 48 implants were placed into sockets in three minipigs. Abutments were placed protruding into the oral cavity 4 mm in height for immediate loading. Crestal areas and intrabony spaces were filled with PPCH-PA, PPCH, or PA using a three-phase delivery system in which all graft materials were hardened by a light cure. In the negative control group, implant sites were left untreated. At 12 weeks, block sections containing implants were obtained. Evaluations included periodontal probing, pullout-force load, and stability measurements to determine implant stability, radiographs to examine bone levels, and scanning electron microscopy (SEM)-energy-dispersed spectroscopy to determine bone-to-implant contact. Probing measurements did not reveal any pathologic pocket formation or bone loss. Radiographs revealed that immediate implant placement and loading resulted in bone at or slightly apical to the first thread of the implant in all groups at 12 weeks. Stability test values showed a relative clinical stability for all implants (range: -7 to +1); however, implants augmented with PPCH-PA exhibited a statistically significantly greater stability compared to all other groups (P <0.05). The newly formed bone in PPCH-PA-treated sites was well organized with less marrow spaces and well-distributed osteocytes. SEM revealed a tighter implant-socket interface in the PPCH-PA group compared to other groups with reduced microfissures

  10. The Use of Light/Chemically Hardened Polymethylmethacrylate, Polyhydroxyethylmethacrylate, and Calcium Hydroxide Graft Material in Combination With Polyanhydride Around Implants in Minipigs: Part I: Immediate Stability and Function

    PubMed Central

    Hasturk, Hatice; Kantarci, Alpdogan; Ghattas, Mazen; Schmidt, Marcella; Giordano, Russell A.; Ashman, Arthur; Diekwisch, Thomas G.; Van Dyke, Thomas

    2015-01-01

    Background The present study is designed as a proof-of-concept study to evaluate light/chemical hardening technology and a newly formulated polymethylmethacrylate, polyhydroxyethylmethacrylate, and calcium hydroxide (PPCH) plus polyanhydride (PA) (PPCH-PA) composite graft material as a bone substitute compared to positive and negative controls in a minipig model. Methods PPCH-PA (composite graft); PPCH alone (positive control), PA alone (positive control), and no graft (negative control) were compared. Four mandibular premolar teeth per quadrant were extracted; a total of 48 implants were placed into sockets in three minipigs. Abutments were placed protruding into the oral cavity 4 mm in height for immediate loading. Crestal areas and intrabony spaces were filled with PPCH-PA, PPCH, or PA using a three-phase delivery system in which all graft materials were hardened by a light cure. In the negative control group, implant sites were left untreated. At 12 weeks, block sections containing implants were obtained. Evaluations included periodontal probing, pullout-force load, and stability measurements to determine implant stability, radiographs to examine bone levels, and scanning electron microscopy (SEM)–energy-dispersed spectroscopy to determine bone-to-implant contact. Results Probing measurements did not reveal any pathologic pocket formation or bone loss. Radiographs revealed that immediate implant placement and loading resulted in bone at or slightly apical to the first thread of the implant in all groups at 12 weeks. Stability test values showed a relative clinical stability for all implants (range: −7 to +1); however, implants augmented with PPCH-PA exhibited a statistically significantly greater stability compared to all other groups (P <0.05). The newly formed bone in PPCH-PA–treated sites was well organized with less marrow spaces and well-distributed osteocytes. SEM revealed a tighter implant–socket interface in the PPCH-PA group compared to other

  11. Reconstructing past seawater Mg/Ca and Sr/Ca from mid-ocean ridge flank calcium carbonate veins.

    PubMed

    Coggon, Rosalind M; Teagle, Damon A H; Smith-Duque, Christopher E; Alt, Jeffrey C; Cooper, Matthew J

    2010-02-26

    Proxies for past seawater chemistry, such as Mg/Ca and Sr/Ca ratios, provide a record of the dynamic exchanges of elements between the solid Earth, the atmosphere, and the hydrosphere and the evolving influence of life. We estimated past oceanic Mg/Ca and Sr/Ca ratios from suites of 1.6- to 170-million-year-old calcium carbonate veins that had precipitated from seawater-derived fluids in ocean ridge flank basalts. Our data indicate that before the Neogene, oceanic Mg/Ca and Sr/Ca ratios were lower than in the modern ocean. Decreased ocean spreading since the Cretaceous and the resulting slow reduction in ocean crustal hydrothermal exchange throughout the early Tertiary may explain the recent rise in these ratios.

  12. Randomized, placebo-controlled study of the efficacy of a calcium phosphate containing paste on dentin hypersensitivity.

    PubMed

    Mehta, Deepak; Gowda, Vishwas; Finger, Werner J; Sasaki, Keiichi

    2015-11-01

    Hypersensitivity of non-carious cervical lesions (DH) is a frequently encountered disease. This randomized, controlled, single-blind crossover study evaluated the effectiveness of a calcium phosphate containing desensitizer paste (TAP) on DH in comparison to water as placebo (PLA). In this clinical trial 35 patients were randomly assigned to the test and the negative control group. Using a 10cm long VAS (visual analog scale) patients should respond with DH score >6 on one tooth in each of two quadrants for allocation. Pain stimuli were a 2-seconds air blast (AB) and probe scratching (PS) of the exposed dentin. VAS scores were determined pre-operatively (PRE), immediately after treatment (POST), at 1 week, 1, 3 and finally after 6 months. Both TAP and PLA applications decreased DH significantly at POST and throughout the 6-months recalls (p<0.001). Pain reductions upon AB stimulation of TAP treated teeth, assessed at POST and 6 months were 35 and 55%, upon PS stimuli 21 and 54%, respectively. PLA treated lesions responded to AB at POST and after 6 months with 20 and 36% pain reduction, to PS with 11 and 30% pain reduction, respectively. Differences between TAP and PLA pain scores were statistically significant at all recalls (p<0.05). TAP paste reduced DH successfully during this 6-months trial. The calcium phosphate crystallites included in the paste and the presumed hydroxyapatite precipitates upon exposure to saliva were hypothetically able to occlude open dentinal tubules, at least to some extent. TAP is considered a biocompatible desensitizer paste. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  13. Efficacy of Needle, Ultrasonic, and Endoactivator Irrigation and Photon-Induced Photoacoustic Streaming in Removing Calcium Hydroxide from the Main Canal and Isthmus: An In Vitro Micro-Computed Tomography and Scanning Electron Microscopy Study.

    PubMed

    Li, Dongxia; Jiang, Shan; Yin, Xingzhe; Chang, Jeffrey Wen Wei; Ke, Jie; Zhang, Chengfei

    2015-06-01

    The aim of this in vitro study was to use high-resolution micro-computed tomography (micro-CT) and scanning electron microscopy (SEM) to compare the efficacy of four irrigation techniques [needle, ultrasonic, EndoActivator, and photon-induced photoacoustic streaming (PIPS)] in removing calcium hydroxide (Ca[OH]2) from the root canal and isthmus of maxillary premolars. Twenty-four maxillary first premolars were selected based on the presence of isthmus regions on micro-CT scans. Root canals were instrumented with an F2 file using ProTaper rotary instruments and filled with Ca(OH)2 paste. Samples were stored at 37°C and 100% humidity for 1 week and randomly divided into four groups (n=6 each), according to irrigation technique. Samples were scanned with micro-CT before instrumentation, after Ca(OH)2 filling, and after irrigation. Ca(OH)2 reduction in the coronal, middle, and apical thirds and in the isthmus were assessed with three-dimensional image analysis. Next, specimens were split longitudinally, and canal walls were examined with SEM for Ca(OH)2 residues. Data were statistically evaluated with the Kruskal-Wallis and Mann-Whitney tests (p=0.05). The PIPS and ultrasonic groups showed greater Ca(OH)2 reduction in the apical third and higher cleanliness of the isthmus than the EndoActivator and needle irrigation groups (p<0.05). Ca(OH)2 residue scores in the PIPS and ultrasonic groups were significantly lower than those in the EndoActivator and needle groups in all regions of the root canals (p<0.05). There was no significant difference between PIPS and ultrasonic groups (p>0.05), or between EndoActivator and needle groups (p>0.05). PIPS and ultrasonic irrigation more effectively removed Ca(OH)2 from the main canal and isthmus in maxillary premolars than did EndoActivator or needle irrigation.

  14. Injectability of calcium phosphate pastes: Effects of particle size and state of aggregation of β-tricalcium phosphate powders.

    PubMed

    Torres, P M C; Gouveia, S; Olhero, S; Kaushal, A; Ferreira, J M F

    2015-07-01

    The present study discloses a systematic study about the influence of some relevant experimental variables on injectability of calcium phosphate cements. Non-reactive and reactive pastes were prepared, based on tricalcium phosphate doped with 5 mol% (Sr-TCP) that was synthesised by co-precipitation. The varied experimental parameters included: (i) the heat treatment temperature within the range of 800-1100°C; (ii) different milling extents of calcined powders; (iii) the liquid-to-powder ratio (LPR); (iv) the use of powder blends with different particle sizes (PS) and particle size distributions (PSD); (v) the partial replacement of fine powders by large spherical dense granules prepared via freeze granulation method to simulate coarse individual particles. The aim was contributing to better understanding of the effects of PS, PSD, morphology and state of aggregation of the starting powders on injectability of pastes produced thereof. Powders heat treated at 800 and 1000°C with different morphologies but with similar apparent PSD curves obtained by milling/blending originated completely injectable reactive cement pastes at low LPR. This contrasted with non-reactive systems prepared thereof under the same conditions. Hypotheses were put forward to explain why the injectability results collected upon extruding non-reactive pastes cannot be directly transposed to reactive systems. The results obtained underline the interdependent roles of the different powder features and ionic strength in the liquid media on determining the flow and injectability behaviours.

  15. Effect of desensitising paste containing 8% arginine and calcium carbonate on biofilm formation of Streptococcus mutans in vitro.

    PubMed

    Fu, Dongjie; Pei, Dandan; Huang, Cui; Liu, Yinchen; Du, Xijin; Sun, Hualing

    2013-07-01

    To evaluate the influence of desensitising paste containing 8% arginine and calcium carbonate (Ar-Ca) on biofilm formation on dentine. Dentine discs were cut from extracted third molars and divided into the following three groups: no treatment, pumice treatment and Ar-Ca treatment. Surface topography and roughness were examined using scanning electron microscopy (SEM) and non-contact 3D surface profiler. After sterilisation, samples were incubated with Streptococcus mutans (S. mutans) for 4 h, 24 h and 72 h. Bacterial adhesion and biofilm formation were analysed using SEM, whereas MTT and lactic acid production assays were used to analyse the metabolic activity of S. mutans. After polishing with either pumice or Ar-Ca, the surfaces of the samples became smoother than in the control group. The Ra values of the three experimental groups decreased significantly to 0.43 μm, 0.3 μm and 0.26 μm, respectively. Compared to the control group, fewer bacteria adhered to the dentine surface in the Ar-Ca group, while biofilm thickness decreased significantly for both groups after incubating for 24 h and 72 h. MTT and lactic acid production levers also showed a significant reduction in the Ar-Ca group. Ar-Ca appears to present antibiofilm efficacy and may provide a promising approach to combat bacterial infection in hypersensitive dentinal lesions. As a clinical application of desensitising polishing paste, the paste containing 8% arginine and calcium carbonate could also inhibit the biofilm formation effectively. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  16. Assessment of Pain Intensity in Patients with Dentin Hypersensitivity After Application of Prophylaxis Paste Based on Calcium Sodium Phosphosilicate Formula.

    PubMed

    Chałas, Renata; Wójcik-Chęcińska, Ilona; Zamościńska, Jolanta; Bachanek, Teresa

    2015-10-01

    One of many functions of the pulp-dentin complex is sensory function. Acute, situated, receding pain after the cessation of the stimulus action is called dentin pain. Dentin hypersensitivity has been described as one of the most painful and least successfully treated chronic ailments of teeth. The aim of this research was the clinical evaluation of the effectiveness of professional polishing paste containing calcium sodium phosphosilicate formula (NovaMin) in eliminating dentin hypersensitivity after a single application. The study comprised 92 teeth with dentin hypersensitivity diagnosed on the basis of history and clinical examination. The pain reaction of exposed dentine was induced by tactile and dehydrating stimuli, asking patients to assess the severity of pain on the VAS scale. Clinical trial and survey were carried out twice: before and 1 week after the application of the polishing paste. After the application of the examined paste, the percentage of teeth reacting with a severe pain to the touch of the probe decreased from 16.3% to 4.3%, and with a moderate pain from 42.4% to 12%. Examination after applying dehydrating stimulus a week after carrying out the application showed a decrease in the proportion of teeth with strong pain from 28.3% to 0% and moderate pain from 38% to 15.2%. The lack of pain increased from 12% to about 50%. The use of prophylactic professional paste with NovaMin formula in in-office procedure provides the reduction of dentin hypersensitivity noticeable by 1 week after application.

  17. Assessment of Pain Intensity in Patients with Dentin Hypersensitivity After Application of Prophylaxis Paste Based on Calcium Sodium Phosphosilicate Formula

    PubMed Central

    Chałas, Renata; Wójcik-Chęcińska, Ilona; Zamościńska, Jolanta; Bachanek, Teresa

    2015-01-01

    Background One of many functions of the pulp-dentin complex is sensory function. Acute, situated, receding pain after the cessation of the stimulus action is called dentin pain. Dentin hypersensitivity has been described as one of the most painful and least successfully treated chronic ailments of teeth. The aim of this research was the clinical evaluation of the effectiveness of professional polishing paste containing calcium sodium phosphosilicate formula (NovaMin) in eliminating dentin hypersensitivity after a single application. Material/Methods The study comprised 92 teeth with dentin hypersensitivity diagnosed on the basis of history and clinical examination. The pain reaction of exposed dentine was induced by tactile and dehydrating stimuli, asking patients to assess the severity of pain on the VAS scale. Clinical trial and survey were carried out twice: before and 1 week after the application of the polishing paste. Results After the application of the examined paste, the percentage of teeth reacting with a severe pain to the touch of the probe decreased from 16.3% to 4.3%, and with a moderate pain from 42.4% to 12%. Examination after applying dehydrating stimulus a week after carrying out the application showed a decrease in the proportion of teeth with strong pain from 28.3% to 0% and moderate pain from 38% to 15.2%. The lack of pain increased from 12% to about 50%. Conclusions The use of prophylactic professional paste with NovaMin formula in in-office procedure provides the reduction of dentin hypersensitivity noticeable by 1 week after application. PMID:26429677

  18. Minipig-BMSCs Combined with a Self-Setting Calcium Phosphate Paste for Bone Tissue Engineering.

    PubMed

    Qiu, Gengtao; Wang, Ping; Li, Guangjun; Shi, Zhanjun; Weir, Michael D; Sun, Jinyu; Song, Yang; Wang, Jixing; Xu, Huakun H; Zhao, Liang

    2016-11-01

    Calcium phosphate cements (CPCs) are a new generation of bone repair materials with good biocompatibility for various stem cells. The minipig is a recommended large animal model for bone engineering research. This study aimed to evaluate the feasibility of utilizing CPC scaffolds for the adhesion, proliferation, and osteogenic differentiation of minipig's bone marrow mesenchymal stem cells (pBMSCs). Passage 3 pBMSCs were seeded on the CPC scaffold and cultured with osteogenic culture medium (osteogenic group) or normal medium (control group). The density of viable cells increased in both groups, and pBMSCs firmly attached and spread well on the CPC scaffold. The alkaline phosphatase (ALP) activity in the osteogenic group had significantly increased on day 7 (D7) and peaked on D14. qRT-PCR revealed that mRNA levels of ALP and three osteogenic marker genes were significantly higher on D4, D7, and D14 in the osteogenic group. Alizarin Red S staining showed a significantly higher degree of bone mineralization from D7, D14 to D21 in the osteogenic group. These results indicated that pBMSCs can attach, proliferate well on CPC scaffold, and be successfully induced to differentiate into osteogenic cells. Our findings may be helpful for bone tissue engineering and the studies of bone regeneration.

  19. Past daily light cycle recorded in the strontium/calcium ratios of giant clam shells.

    PubMed

    Sano, Yuji; Kobayashi, Sayumi; Shirai, Kotaro; Takahata, Naoto; Matsumoto, Katsumi; Watanabe, Tsuyoshi; Sowa, Kohki; Iwai, Kenji

    2012-03-27

    The historical record of daily light cycle in tropical and subtropical regions is short. Moreover, it remains difficult to extract this cycle in the past from natural archives such as biogenic marine carbonates. Here we describe the precise analysis of Sr/Ca, Mg/Ca, and Ba/Ca ratios in a cultivated giant clam shell, using a laterally high-resolution secondary ion mass spectrometer with 2 μm resolution. The Sr/Ca ratio exhibits striking diurnal variations, reflecting the daily light cycle. A clear seasonal variation in Sr/Ca is also observed in another longer set of measurements with 50 μm resolution. Light-enhanced calcification and elemental transportation processes, in giant clam and symbiotic algae, may explain these diurnal and annual variations. This opens the possibility to develop the Sr/Ca ratio from a giant clam shell as an effective proxy for parameters of the daily light cycle.

  20. Effect of calcium formate as an accelerator on the physicochemical and mechanical properties of pozzolanic cement pastes

    SciTech Connect

    Heikal, Mohamed

    2004-06-01

    The aim of the present work is to study the effect of calcium formate (CF) as an accelerator on the properties of pozzolanic cement pastes. Three types of cements were used in this investigation. These cements were OPC and pozzolanic cements containing 80 mass% OPC and 20 mass% silica fume (SF) or 20 mass% ground clay bricks (GCB). The dosages of CF were 0.00, 0.25, 0.50, and 0.75 mass% of cement. The compressive strength, total porosity, and hydration kinetics such as free lime and combined water contents were investigated. The results obtained in this study showed that the addition of CF shortens the initial and final setting times and increases the compressive strength and combined water content as well as gel/space ratio at all ages of hydration. On the other hand, it decreases the total porosity. CF activates the liberation of Ca(OH){sub 2} of OPC pastes. The free lime content of pozzolanic cement in the presence of CF increases up to 7 days, then decreases at the later ages of hydration.

  1. Calcium.

    PubMed

    Williams, Robert J P

    2002-01-01

    This chapter describes the chemical and biological value of the calcium ion. In calcium chemistry, our main interest is in equilibria within static, nonflowing systems. Hence, we examined the way calcium formed precipitates and complex ions in solution. We observed thereafter its uses by humankind in a vast number of materials such as minerals, e.g., marble, concrete, mortars, which parallel the biological use in shells and bones. In complex formation, we noted that many combinations were of anion interaction with calcium for example in the uses of detergents and medicines. The rates of exchange of calcium from bound states were noted but they had little application. Calcium ions do not act as catalysts of organic reactions. In biological systems, interest is in the above chemistry, but extends to the fact that Ca2+ ions can carry information by flowing in one solution or from one solution to another through membranes. Hence, we became interested in the details of rates of calcium exchange. The fast exchange of this divalent ion from most organic binding sites has allowed it to develop as the dominant second messenger. Now the flow can be examined in vitro as calcium binds particular isolated proteins, which it activates as seen in physical mechanical changes or chemical changes and this piece-by-piece study of cells is common. Here, however, we have chosen to stress the whole circuit of Ca2+ action indicating that the cell is organized both at a basal and an activated state kinetic level by the steady state flow of the ion (see Fig. 11). Different time constants of exchange utilizing very similar binding constants lead to: 1) fast responses as in the muscle of an animal; or 2) slower change as in differentiation of an egg or seed. Many other changes of state may relate to Ca2+ steady-state levels of flow in the circuitry and here we point to two: 1) dormancy in reptiles and animals; and 2) sporulation in both bacteria and lower plants. In the other chapters of

  2. Production of edible carbohydrates from formaldehyde in a spacecraft. pH variations in the calcium hydroxide catalyzed formose reaction. Final Report, 1 Jul. 1973 - 30 Jun. 1974. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Weiss, A. H.; Kohler, J. T.; John, T.

    1974-01-01

    The study of the calcium hydroxide catalyzed condensation of formaldehyde was extended to a batch reactor system. Decreases in pH were observed, often in the acid regime, when using this basic catalyst. This observation was shown to be similar to results obtained by others using less basic catalysts in the batch mode. The relative rates of these reactions are different in a batch reactor than in a continuous stirred tank reactor. This difference in relative rates is due to the fact that at any degree of advancement in the batch system, the products have a history of previous products, pH, and dissolved catalyst. The relative rate differences can be expected to yield a different nature of product sugars for the two types of reactors.

  3. Influence of Past Changes in Atmospheric CO2 on Boron/Calcium of Planktic Fossil Foraminifera

    NASA Astrophysics Data System (ADS)

    Domeyko, R. A.; Allen, K. A.; deMenocal, P. B.

    2014-12-01

    Culture experiments have revealed that B/Ca of shells grown by the foraminiferal species Globigerinoides ruber increase with increasing seawater pH. Specifically, B/Ca responds to changes in the relative abundance of pH-sensitive dissolved carbon and boron species (Allen et al. 2011, 2012). Here, we present a high-resolution study on fossilized G. ruber from two sites in North Atlantic subtropical gyres (VM25-21 and ODP 1055B) through 20 ka BP to evaluate how B/Ca responds to past changes in atmospheric CO2. Forams were picked and crushed gently, then cleaned and dissolved using a variation of the Boyle and Keigwin (1985) and Barker et al. (2003) cleaning protocols prior to analysis. ODP 1055B (from Carolina Slope, West Atlantic) produced a high-resolution record with lower B/Ca values during the glacial period followed by a rapid shift to higher B/Ca values in the early deglaciation, with values remaining high through the Holocene. These results were not predicted by culture calibrations, but they are consistent with B/Ca records from the Caribbean (ODP 999, Foster et al. 2008), suggesting this pattern is characteristic of surface waters in the greater North Atlantic region.

  4. Concentration of Calcium, Phosphate and Fluoride Ions in Microbial Plaque and Saliva after Using CPP-ACP Paste in 6-9 year-old Children.

    PubMed

    Hr, Poureslami; Ra, Hoseinifar; Re, Hoseinifar; H, Sharifi; P, Poureslami

    2016-06-01

    Dental caries is one of the most common chronic diseases in children. The balance between demineralization and remineralization of the decayed teeth depends on the calcium and phosphate content of the tooth surface. Therefore, if a product such as casein phospho peptides - amorphous calcium phosphate (CPP- ACP) which can significantly increase the availability of calcium and phosphate in the plaque and saliva should have an anti-caries protective effect. The purpose of this study was to evaluate the concentration of calcium, phosphate and fluoride in the plaque and saliva of children before and after applying the CPP-ACP paste. A total of 25 children aged between 6-9 years were selected for this clinical trial study. At first, 1 ml of unstimulated saliva was collected and then 1 mg of the plaque sample was collected from the buccal surfaces of the two first primary molars on the upper jaw. In the next step, CPP-ACP paste (GC Corp, Japan) was applied on the tooth surfaces and then the plaque and saliva sampling was performed after 60 minutes. The amount of calcium ions was measured by Ion meter instrument (Metrohm Co, Swiss) and the amounts of phosphate and fluoride ions were measured by Ion Chromatography instrument (Metrohm Co, Swiss). Data were analyzed using paired t-test at a p < 0.05 level of significance. There were statistically significant differences in the calcium and phosphate concentration of the saliva and plaque before and after applying the CPP-ACP paste. There were also statistically significant differences in the fluoride levels of the plaque before and after applying the CPP-ACP paste. However, there were no statistically significant differences in the fluoride levels of the saliva before and after applying the CPP-ACP paste. In this study, the use of the CPP-ACP paste significantly increased the fluoride levels of the plaque and the calcium and phosphate levels of both saliva and plaque. Hence, CPP-ACP paste can facilitate the remineralization of

  5. Concentration of Calcium, Phosphate and Fluoride Ions in Microbial Plaque and Saliva after Using CPP-ACP Paste in 6-9 year-old Children

    PubMed Central

    HR, Poureslami; Ra, Hoseinifar; Re, Hoseinifar; H, Sharifi; P, Poureslami

    2016-01-01

    Statement of Problem: Dental caries is one of the most common chronic diseases in children. The balance between demineralization and remineralization of the decayed teeth depends on the calcium and phosphate content of the tooth surface. Therefore, if a product such as casein phospho peptides - amorphous calcium phosphate (CPP- ACP) which can significantly increase the availability of calcium and phosphate in the plaque and saliva should have an anti-caries protective effect. Objectives: The purpose of this study was to evaluate the concentration of calcium, phosphate and fluoride in the plaque and saliva of children before and after applying the CPP-ACP paste. Materials and Methods: A total of 25 children aged between 6-9 years were selected for this clinical trial study. At first, 1 ml of unstimulated saliva was collected and then 1 mg of the plaque sample was collected from the buccal surfaces of the two first primary molars on the upper jaw. In the next step, CPP-ACP paste (GC Corp, Japan) was applied on the tooth surfaces and then the plaque and saliva sampling was performed after 60 minutes. The amount of calcium ions was measured by Ion meter instrument (Metrohm Co, Swiss) and the amounts of phosphate and fluoride ions were measured by Ion Chromatography instrument (Metrohm Co, Swiss). Data were analyzed using paired t-test at a p < 0.05 level of significance. Results: There were statistically significant differences in the calcium and phosphate concentration of the saliva and plaque before and after applying the CPP-ACP paste. There were also statistically significant differences in the fluoride levels of the plaque before and after applying the CPP-ACP paste. However, there were no statistically significant differences in the fluoride levels of the saliva before and after applying the CPP-ACP paste. Conclusions: In this study, the use of the CPP-ACP paste significantly increased the fluoride levels of the plaque and the calcium and phosphate levels of both

  6. SEPARATION OF PLUTONIUM HYDROXIDE FROM BISMUTH HYDROXIDE

    DOEpatents

    Watt, G.W.

    1958-08-19

    An tmproved method is described for separating plutonium hydroxide from bismuth hydroxide. The end product of the bismuth phosphate processes for the separation amd concentration of plutonium is a inixture of bismuth hydroxide amd plutonium hydroxide. It has been found that these compounds can be advantageously separated by treatment with a reducing agent having a potential sufficient to reduce bismuth hydroxide to metalltc bisinuth but not sufficient to reduce the plutonium present. The resulting mixture of metallic bismuth and plutonium hydroxide can then be separated by treatment with a material which will dissolve plutonium hydroxide but not metallic bismuth. Sodiunn stannite is mentioned as a preferred reducing agent, and dilute nitric acid may be used as the separatory solvent.

  7. Induction of cytotoxicity, oxidative stress and genotoxicity by root filling pastes used in primary teeth.

    PubMed

    Pires, C W; Botton, G; Cadoná, F C; Machado, A K; Azzolin, V F; da Cruz, I B M; Sagrillo, M R; Praetzel, J R

    2016-08-01

    To evaluate the cytotoxicity, oxidative stress and genotoxicity in vitro of four iodoform pastes and three calcium hydroxide pastes. Peripheral blood mononuclear cells (PBMCs) and pure calf thymus DNA (dsDNA) were exposed to extracts of the pastes. Cytotoxicity was assessed with the MTT assay. Generation of reactive oxygen species (ROS) was evaluated using a DCFH-DA assay, and lipid peroxidation was evaluated using a TBARS assay. Genotoxicity was evaluated using the alkaline comet assay and Genomodifier capacity assay (GEMO). All tests were performed after 24 h and 72 h of cell exposure, except GEMO. After performing the Kolmogorov-Smirnov test, data were analysed by Kruskal-Wallis and Dunn's post-tests, and anova with Dunnett's post-test, with a significance level established at P < 0.05. The MTT assay revealed that chlorhexidine, Maxitrol and neomycin sulphate + bacitracin pastes decreased cell viability after 24 h (P < 0.05). No group was associated with a significant decreased cell viability or lipid peroxidation after 72 h. Calcium hydroxide pastes increased the cell viability levels at both experimental times (P < 0.05). Lipid peroxidation was observed with the exposure of cells to calcium hydroxide pastes after 24 h (P < 0.05). Exposure to chlorhexidine, Guedes-Pinto and calcium hydroxide pastes resulted in a significant increase in ROS after 24 h (P < 0.05), whereas iodoform pastes and Calen thickened with zinc oxide significantly increased the ROS after 72 h (P < 0.05). The comet assay revealed that exposure of the PBMCs to iodoform pastes did not damage DNA at either period of time (P > 0.05). However, chlorhexidine paste caused DNA damage in dsDNA (P < 0.05). Calcium hydroxide pastes caused DNA damage in both tests (P < 0.05). The pastes varied in their ability to induce cytotoxicity, genotoxicity and oxidative stress. In general, Guedes-Pinto, Maxitrol and neomycin sulphate + bacitracin pastes exhibited better biocompatibility

  8. Assessment of diffusion of hydroxyl and calcium ions of root canal filling materials in primary teeth.

    PubMed

    Ximenes, Marcos; Cardoso, Mariane

    2012-01-01

    The purpose of this study was to evaluate the diffusion of hydroxyl (OH-) and calcium (Ca+2) of 2 intracanal calcium hydroxide-based medications through the root dentin and cementum of primary teeth. Forty roots were selected and a single operator instrumented the canals. The irrigation was performed with a 1% sodium hypochlorite solution, and a final irrigation used 17% ethylenediaminetetraacetic acid solution. The teeth were divided into 3 groups: (1) group 1 (N=15)- thickened calcium hydroxide paste blended with propylene glycol paste; (2) group 2 (N=15)-Calen; and (3) group 3 (N=10)-no medication. Diffusion of the OH-ions was determined using a digital pH meter, and diffusion of Ca+2 ions was determined through atomic absorption spectrometry at baseline, 24 hours, 7 days, 15 days, and 30 days later. Two-way analysis of variance and Tukey's test revealed that Group 1 achieved significantly higher pH values (P<.01), followed by Groups 2 and 3. There was a statistically significant difference between groups (P<.01) in the amount of Ca+2 ions released; group 1 had the highest diffusion values, followed by group 2, both with peak diffusion at 7 days. Thickened calcium hydroxide paste blended with propylene glycol paste achieved the greatest diffusion of hydroxyl and calcium through the dentin and cementum of primary teeth.

  9. The microstructure of Portland cement paste and its relationship to drying shrinkage: A study of blended cement paste

    NASA Astrophysics Data System (ADS)

    Olson, Rudolph Andrew, III

    1998-12-01

    The objective was to understand how the microstructure of cement paste influences its susceptibility to drying shrinkage. The strategy was to vary the microstructure via processing and relate the changes to the deformation behavior. There were many processing parameters to choose from that were capable of varying the microstructure, but one very effective way was through addition of mineral admixtures. Since the use of mineral admixtures also has the potential to address current economic, social, and environmental problems, achieving a better understanding of blended cement paste was an added benefit. Ground granulated blast furnace slag, fly ash, and silica fume were the mineral admixtures chosen for this study because they represent a wide range of reactivity. Blended cement pastes of various compositions and degrees of hydration were characterized. Calcium hydroxide, calcium silicate hydrate, pH, free water, and nitrogen surface area were the microstructural parameters chosen for analysis. Because calcium silicate hydrate is usually measured by indirect techniques which are not applicable to blended cements, a technique based on water adsorption was developed; results compared favorably with calculations from the Jennings-Tennis hydration model. The connectivity of the pore network was characterized using impedance spectroscopy. Drying shrinkage was analyzed on the macrolevel using bulk shrinkage measurements and the microstructural level using a deformation mapping technique. Several processing-microstructure-property relationships were developed. Mineral admixtures were found to significantly reduce the connectivity of the pore network and increase the nitrogen surface area of cement paste per gram of calcium silicate hydrate. The bulk drying shrinkage of blended cement pastes dried to 50% relative humidity was found to depend primarily on calcium hydroxide and calcium silicate hydrate content; shrinkage decreased with increasing amounts of calcium hydroxide

  10. Clinical evaluation of an in-office desensitizing paste containing 8% arginine and calcium carbonate for relief of dentin hypersensitivity prior to dental prophylaxis.

    PubMed

    Tsai, Wellington S; Placa, Sally-Jo; Panagakos, Fotinos S

    2012-06-01

    To evaluate the clinical efficacy of a professional prophylaxis paste containing 8% arginine-calcium carbonate in the reduction of dentin hypersensitivity used as a pre-procedural application compared to a commercially-available prophylaxis paste. This study was conducted at Jersey Shore University Medical Center in Neptune, New Jersey, USA. A mixed population of adult males and females between the ages of 18-70 were included in the study. Baseline air blast hypersensitivity score of 2 or 3 (Schiff Cold Air Sensitivity Scale) were mandatory for inclusion in this study. Subjects were randomly assigned to either: (1) Control paste, Nupro non-fluoridated pumice based prophylaxis paste (Dentsply Professional) or (2) Test paste, a desensitizing paste containing 8% arginine and calcium carbonate (Colgate-Palmolive Company). Either the Control or Test paste was applied to subjects prior to their receiving a routine dental prophylaxis. After completion of the dental cleaning procedure, a final post-cleaning air blast examination was performed on each subject following identical methods as at the baseline exam. Paired t-tests and ANCOVA were used. 66 subjects were enrolled in the study. Following the post-cleaning air blast hypersensitivity examination, there was a significant decrease of 83.94% in the hypersensitivity of subjects using the Test paste. The group using the Control paste showed a 13.43% desensitization. There was a statistically significant difference of 79.65% between the two groups. Subjects in the age groups 41-50, 51-60, and 61-70 years of age showed the most reduction in dentin hypersensitivity.

  11. Efficacy of self-adjusting file, XP-endo finisher and passive ultrasonic irrigation on the removal of calcium hydroxide paste from an artificial standardized groove.

    PubMed

    Kfir, Anda; Blau-Venezia, Nuphar; Goldberger, Tomer; Abramovitz, Itzhak; Wigler, Ronald

    2017-06-23

    The purpose of this study was to compare the effectiveness of self-adjusting file (SAF), XP-endo finisher (XP), passive ultrasonic irrigation (PUI) and conventional syringe and needle irrigation (SNI) in the removal of Ca(OH)2 from an artificial groove. Eighty mandibular incisors with single oval canals were prepared to size 40/0.04 and split longitudinally. A standardised groove was prepared in the apical third and filled with Ca(OH)2 . The root halves were reassembled and divided into two control groups (n = 4) and four experimental groups (n = 18) according to the removal methods used. The amount of residual Ca(OH)2 was evaluated using a four-grade scoring system. The differences among the groups were analysed using the Kruskal-Wallis test (P < 0.05). SAF, XP and PUI removed significantly more Ca(OH)2 than SNI (P < 0.001), although there were no significant differences among them (P = 0.209). None of the tested methods could completely clean Ca(OH)2 from the groove. © 2017 Australian Society of Endodontology Inc.

  12. Sodium hydroxide poisoning

    MedlinePlus

    Sodium hydroxide is a very strong chemical. It is also known as lye and caustic soda. This ... poisoning from touching, breathing in (inhaling), or swallowing sodium hydroxide. This article is for information only. Do ...

  13. Mechanisms of mineral membrane fouling growth modulated by pulsed modes of current during electrodialysis: evidences of water splitting implications in the appearance of the amorphous phases of magnesium hydroxide and calcium carbonate.

    PubMed

    Cifuentes-Araya, Nicolás; Astudillo-Castro, Carolina; Bazinet, Laurent

    2014-07-15

    Experiments revealed the fouling nature evolutions along different electrodialysis (ED) trials, and how it disappears when current pulsation acts repetitively on the interfaces of ion-exchange membranes (IEMs). Fouling was totally controlled on the diluate side of cation-exchange membrane (CEM) by the repetitive pulsation frequency of the higher on-duty ratios applied. They created steady water splitting proton-barriers that neutralized OH(-) leakage through the membrane, decreasing the interfacial pH, and fouling of the concentrate side. The anion-exchange membrane (AEM) on the diluate side was similarly protected, but it was fouled once water splitting OH(-) generation became either intense enough or excessively weak. Interestingly, amorphous magnesium hydroxide (AMH) stemmed on the CEM-diluate side from brucite under intense water splitting OH(-) generation, and/or strong OH(-) leakage electromigration through the membrane. Water dissociation and overlimiting current regimes triggered drastic water molecule removal from crystal lattices through an accelerated cascade water splitting reaction. Also, amorphous calcium carbonate (ACC) appeared on CEM under intense water splitting reaction, and disappeared once intense OH(-) leakage was allowed by the water splitting proton-barrier dissipation. Our findings have implications for membrane fouling control, as well as for the understanding of the growth behavior of CaCO3 and Mg(OH)2 species on electromembrane interfaces. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Clinical evaluation of the efficacy of a desensitizing paste containing 8% arginine and calcium carbonate for the in-office relief of dentin hypersensitivity associated with dental prophylaxis.

    PubMed

    Hamlin, David; Williams, Kathleen Phelan; Delgado, Evaristo; Zhang, Yun Po; DeVizio, William; Mateo, Luis R

    2009-03-01

    To evaluate the clinical efficacy in reducing dentin hypersensitivity of a professional desensitizing paste containing 8% arginine and calcium carbonate relative to that of a commercially-available pumice prophylaxis paste when applied pre-procedurally to a professional dental cleaning (dental prophylaxis). This was a single-center, parallel group, double-blind, stratified clinical study, conducted in Langhorne, Pennsylvania. Adult male and female subjects who presented a tactile hypersensitivity score (Yeaple Probe) between 10 and 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. The two treatment groups were: (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 had their assigned paste applied immediately before receiving a professional dental cleaning procedure. After the completion of the dental cleaning procedure, tactile and air blast dentin hypersensitivity examinations were again performed following the same methodology employed for the baseline hypersensitivity examinations. 45 subjects completed the study. At the final hypersensitivity examinations, conducted immediately after the completion of the dental cleaning procedure, subjects assigned to the test group exhibited statistically significant improvements from baseline with respect to baseline-adjusted mean tactile (132.1%) and air blast hypersensitivity scores (48.6%). Additionally, subjects assigned to the control group exhibited a statistically significant hypersensitivity improvement from baseline with respect to baseline-adjusted mean air blast hypersensitivity scores (13.9%). The hypersensitivity improvement from baseline indicated for the control group for mean

  15. Effect of an 8.0% arginine and calcium carbonate in-office desensitizing paste on the shear bond strength of composites to human dental enamel.

    PubMed

    García-Godoy, Alexander; García-Godoy, Franklin

    2010-12-01

    To evaluate the effect of 8.0% arginine and calcium carbonate, in-office desensitizing paste (Colgate Sensitive Pro-Relief Desensitizing Paste) on the shear bond strength of composites to human dental enamel. Two resin composites (Filtek Supreme, Premise) and human dental enamel were used. 16 samples per composite were prepared. Caries-free extracted human molars, not older than 3 months, and stored in distilled water were used for this portion of the experiment. Buccal and lingual surfaces were polished with high polishing pastes to create a uniform flat surface area to which the cylindrical composite samples were bonded. After polishing, the samples were rinsed in tap water and stored at 100% relative humidity. The resin composites were used to form cylindrical samples 3 mm x 1.6 mm, which were light-cured with a Demetron curing light according to the manufacturers' instructions. For each composite, 32 surfaces were used; 16 were a control group with the enamel polished with a water slurry of flour of pumice. The experimental group had the enamel polished with the 8.0% arginine and calcium carbonate desensitizing paste, using disposable latex free prophy cups with a slow speed hand piece at 3,000 rpm using moderate to light pressure, according to manufacturer's instructions. The composite cylinders were bonded to the enamel with their respective etching agents and adhesives and left in distilled water for 48 hours, after which the samples were sheared with an Instron testing machine at 0.5 mm/minute. After shearing, all samples were analyzed with a stereo microscope to evaluate failure pattern (failure at the enamel surface, failure at the composite surface, or mixed failure, at both enamel and composite surfaces). SEM images of selected surfaces were made to depict the overall morphology of the surface of dental materials used after 8.0% arginine and calcium carbonate desensitizing paste, application and shear strength tests. ANOVA and Student-Newman-Keuls tests

  16. Effect of a functional desensitizing paste containing 8% arginine and calcium carbonate on the microtensile bond strength of etch-and-rinse adhesives to human dentin.

    PubMed

    Yang, Hongye; Pei, Dandan; Liu, Siying; Wang, Yake; Zhou, Liqun; Deng, Donglai; Huang, Cui

    2013-06-01

    To evaluate (1) the effect of a desensitizing paste containing 8% arginine and calcium carbonate on the microtensile bond strength between dentin and etch-and-rinse adhesive systems; and (2) to examine the dentin tubules occlusion quantitatively. 48 freshly extracted intact human mandibular third molars were divided randomly into three groups. The mid-coronal dentin of each tooth was exposed and treated. Group A: no treatment; Group B: specimens were polished with a desensitizing paste containing 8% arginine and calcium carbonate using a rotary cup operating at a low speed for 3 seconds, followed by an additional duration of 3 seconds (total operation time of 6 seconds), according to the manufacturer's instructions; Group C: specimens were handled in the same way with the exception of an increased operation time of 9 seconds, twice (total operation time of 18 seconds). Each group was randomly divided into two subgroups in order to evaluate the effectiveness of two different adhesive agents. A two-step etch-and-rinse adhesive agent (Adper SingleBond 2) and a three-step etch-and-rinse adhesive agent (Adper ScotchBond Multi-purpose) were applied to dentin surfaces. Then, microtensile bond strengths of the six subgroups were tested. Dentin surfaces were analyzed using field-emission scanning electron microscopy (FESEM) and laser scanning confocal microscopy (LSCM). There was no significant difference in microtensile bond strength between the control group and the experimental groups treated with the 8% arginine and calcium carbonate desensitizing paste during the application of etch-and-rinse adhesives. Both FESEM and LSCM showed that the desensitizing paste occluded dentin tubules effectively.

  17. 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.

  18. 21 CFR 184.1201 - Calcium glycerophosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... neutralizing glycerophosphoric acid with calcium hydroxide or calcium carbonate. The commercial product is a... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Calcium glycerophosphate. 184.1201 Section 184... as GRAS § 184.1201 Calcium glycerophosphate. (a) Calcium glycerophosphate (C3H7CaO6P, CAS Reg. No...

  19. 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

  20. 21 CFR 184.1191 - Calcium carbonate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... three common methods of manufacture: (1) As a byproduct in the “Lime soda process”; (2) By precipitation of calcium carbonate from calcium hydroxide in the “Carbonation process”; or (3) By precipitation...

  1. 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.

  2. Individual and combined effects of chloride, sulfate, and magnesium ions on hydrated Portland-cement paste

    SciTech Connect

    Poole, T.S.; Wakeley, L.D.; Young, C.L.

    1994-03-01

    Ground water with a high concentration of magnesium ion is known to cause deterioration to portland cement concretes. A proposed mechanism for this deterioration process published previously involves an approximate 1:1 replacement of Ca ions by Mg ions in the crystalline phases of hydrated cement. The current study was undertaken to determine which ions, among magnesium, chloride, and sulfate, cause deterioration; whether their deleterious action is individual or interdependent; and to relate this mechanism of deterioration to the outlook for a 100-yr service life of concretes used in mass placements at the Waste Isolation Pilot Plant. Loss of Ca ion by cement pastes was found to be strongly related to the concentration of Mg ion in simulated ground-water solutions in which the paste samples were aged. This was true of both salt- containing and conventional cement pastes. No other ion in the solutions exerted a strong effect on Ca loss. Ca ion left first from calcium hydroxide in the pastes, depleting all calcium hydroxide by 60 days. Some calcium silicate hydrate remained even after 90 days in the solutions with the highest concentration of Mg ion, while the paste samples deteriorated noticeably. The results indicated a mechanism that involves dissolution of Ca phases and transport of Ca ions to the surface of the sample, followed by formation of Mg-bearing phases at this reaction surface rather than directly by substitution within the microstructure of hydrated cement. Given that calcium hydroxide and calcium silicate hydrate are the principal strength-giving phases of hydrated cement, this mechanism indicates the likelihood of significant loss of integrity of a concrete exposed to Mg-bearing ground water at the WIPP. The rate of deterioration ultimately will depend on Mg-ion concentration, the microstructure materials of the concrete exposed to that groundwater, and the availability of brine.

  3. The Use of Light/Chemically Hardened Polymethylmethacrylate, Polyhydroxylethylmethacrylate, and Calcium Hydroxide Graft Material in Combination With Polyanhydride Around Implants and Extraction Sockets in Minipigs: Part II: Histologic and Micro-CT Evaluations

    PubMed Central

    Hasturk, Hatice; Kantarci, Alpdogan; Ghattas, Mazen; Dangaria, Smit J.; Abdallah, Rima; Morgan, Elise F.; Diekwisch, Thomas G.H.; Ashman, Arthur; Van Dyke, Thomas

    2015-01-01

    Background This report is the second part of the previously published study on the impact of light/chemical hardening technology and a newly formulated composite graft material for crestal augmentation during immediate implant placement. Methods A total of 48 implants were placed into the sockets of the mesial roots of freshly extracted mandibular premolar teeth in three minipigs. Crestal areas and intrabony spaces were randomly augmented with light-hardened graft materials including a composite graft consisting of polymethylmethacrylate, polyhydroxylethylmethacrylate, and calcium hydroxide (PPCH) plus polyanhydride (PA); PPCH graft; and PA graft, or left untreated. Distal sockets not receiving implants and the sockets of first molars (n = 60) were randomly treated with one of the graft materials or left empty. In addition, two molar sockets were treated with the original PPCH graft material. Quantitative microcomputed tomography (micro-CT) was used to assess alveolar bone structure and tissue compositions. Histologic evaluations included descriptive histology to assess the peri-implant wound healing, as well as histomorphometric measurements to determine bone-to-implant contact (BIC). Results Both trabecular and cortical bone measurements by micro-CT did not reveal any significant differences among the groups. Sites augmented with PPCH+PA resulted in significantly greater BIC surface than PPCH alone and no-graft-treated implants (P <0.05) histologically. Stained ground sections showed complete bone formation between bone and implant surface in the PPCH+PA group, whereas sites without augmentation showed large gaps between bone and implant surfaces, indicating a slower bone apposition and less BIC surface compared to all other groups. Similar to implant sections, all materials showed positive outcome on trabecular and cortical bone formation in extraction sockets with an intact crestal cortical bone. Conclusion Histologic evaluations supported the previous findings

  4. Effect of a desensitizing paste containing 8% arginine and calcium carbonate on the surface roughness of dental materials and human dental enamel.

    PubMed

    Garcia-Godoy, Franklin; Garcia-Godoy, Alexander; Garcia-Godoy, Cristina

    2009-03-01

    To evaluate the effect of an 8% arginine-calcium carbonate fluoride-free desensitizing paste on the surface roughness of resin composite, porcelain, amalgam, gold, and human dental enamel both prior to and following simulated toothbrushing. A resin composite (Filtek Supreme), a commercial porcelain (IPS Empress), an amalgam (Dispersalloy), gold (JIF-PF) and human dental enamel were used, as well as commercial finishing and polishing instruments. Eight two-sided samples were fabricated for each group. The composite and amalgam samples were stored at 100% relative humidity and 37 degrees C for 48 hours prior to measuring the surface roughness and completing the subsequent finishing and polishing procedures. Enamel blocks were cut from human lesion-free teeth and embedded in acrylic. The blocks were then polished flat with high polishing pastes. For gold and porcelain, the same size was used and the materials processed by a professional dental laboratory. Following storage, each surface was polished using the Super-Snap (Shofu) system. The amalgam was polished with conventional polishing techniques. Roughness (Ra and Ry) was evaluated with both a 3D non-contact profilometer and a stylus profilometer. With the two-sided samples only one side was polished with the desensitizing paste and the other side was left unpolished without paste. The 8% arginine-calcium carbonate desensitizing paste was applied to a surface for 15 seconds using a single disposable prophy cup. Each polished surface was measured by the profilometers and three roughness values per surface were recorded as the "initial prophy" surface. Following initial surface analysis, each side of every sample was treated with a simulated toothbrushing technique using a toothbrushing device (V-8). A 50:50 (w/w) slurry of toothpaste (Colgate Cavity Protection) and deionized water was used. Each surface was brushed 10,000 times. Then, the samples were rinsed with tap water and stored in 100% humidity until roughness

  5. Injectable calcium phosphate-alginate-chitosan microencapsulated MC3T3-E1 cell paste for bone tissue engineering in vivo.

    PubMed

    Qiao, Pengyan; Wang, Juan; Xie, Qiufei; Li, Fangfang; Dong, Limin; Xu, Tao

    2013-12-01

    Osteoblasts or stem cells have been delivered into injectable calcium phosphate cement (CPC) to improve its effectiveness and biological function. However, the osteogenic potential of the new construct in vivo has been rarely reported, and there are no reports on alginate-chitosan microencapsulated osteoblasts mixed with CPC. This study aimed to develop alginate-chitosan microencapsulated mouse osteoblast MC3T3-E1 cells (AC-cells), evaluate the osteogenic potential of a calcium phosphate cement complex with these AC-cells (CPC-AC-cell), and trace the implanted MC3T3-E1 cells in vivo. MC3T3-E1 cells were embedded in alginate microcapsules, cultured in osteogenic medium for 7 days, and then covered with chitosan before mixing with a paste of β-tricalcium phosphate/calcium phosphate cement (β-TCP/CPC). The construct was injected into the dorsal subcutaneous area of nude mice. Lamellar-bone-like mineralization, newly formed collagen and angiogenesis were observed at 4 weeks. At 8 weeks, areas of newly formed collagen expanded; further absorption of β-TCP/CPC and osteoid-like structures could be seen. Cell tracing in vivo showed that implanted MC3T3-E1 cells were clearly visible at 2 weeks. These in vivo results indicate that the novel injectable CPC-AC-cell construct is promising for bone tissue engineering applications. © 2013.

  6. Morphological analysis of tissue reaction caused by a new endodontic paste in subcutaneous tissue of rats.

    PubMed

    Marques, André Af; Sponchiado, Emilio C; Garcia, Lucas Fr; Garrido, Angela Db; França, Suzelei C; Lia, Raphael Cc

    2011-07-01

    To assess the biocompatibility of an experimental endodontic paste based on the ethyl acetate fraction of Pothomorphe umbellata + calcium hydroxide, using propylene glycol as vehicle, in connective tissue of rats. Fifteen rats had four polyethylene tubes implanted in their backs, with each one containing the experimental paste. The tube side was considered the control group. After 7, 21, and 42 days, animals were euthanized. Intense inflammatory reaction was noticed after 7 days for experimental paste and it was moderate for control group. At 21 days, the inflammatory reaction was moderate for experimental paste and discrete for control group; and at 42 days, it was discrete for experimental paste and control group. Statistical analysis (Dunn's test, P < 0.01) demonstrated significant difference between the fibrous capsule area at 7 and 42 days (P > 0.01) for experimental paste. Experimental endodontic paste presented satisfactory tissue reaction in the connective tissue of rats.

  7. Effect of home-bleaching gels modified by calcium and/or fluoride and the application of nano-hydroxyapatite paste on in vitro enamel erosion susceptibility.

    PubMed

    Santos, Luciana Floriani Thives Freitas; Torres, Carlos Rocha Gomes; Caneppele, Taciana Marco Ferraz; Magalhães, Ana Carolina; Borges, Alessandra Buhler

    2016-01-01

    This in vitro study compared the effect of bleaching agents modified by the addition of calcium and/or fluoride and the application of a nano-hydroxyapatite paste after bleaching, on the susceptibility of enamel to erosion. Bovine enamel cylindrical samples (3 mm diameter) were assigned to six groups (n = 20 specimens/group) according to the bleaching agent: no bleaching (C-control), 7.5% hydrogen peroxide gel (HP), HP with 0.5% calcium gluconate (HP+Ca), HP with 0.2% sodium fluoride (HP+F), HP with calcium and fluoride (HP+Ca+F) and HP followed by the application of a nano-hydroxyapatite agent (HP+NanoP). The gels were applied on the enamel surface (1 h) followed by cyclic erosive challenges (Sprite Zero®-2 min), for 14 days. The paste was applied after bleaching for 5 min (HP+NanoP). The enamel surface alteration was measured by contact profilometry (µm) (after 7 and 14 days). C-control (mean ± SD: 2.29 ± 0.37 at 7 days/4.86 ± 0.72 at 14 days) showed significantly lower loss compared to the experimental groups. HP+Ca (3.34 ± 0.37/6.75 ± 1.09) and HP+F (4.49 ± 0.92/7.61 ± 0.90) presented significantly lower enamel loss than HP (4.18 ± 0.50/10.30 ± 1.58) only for 14 days and HP+Ca+F (4.92 ± 1.03/8.12 ± 1.52) showed values similar to the HP+F group. The HP+NanoP (5.51 ± 1.04/9.61 ± 1.21) resulted in enamel loss similar to the HP after 14 days. It was found that 7.5% hydrogen peroxide increased the susceptibility of enamel to erosion. The addition of calcium or fluoride to the bleaching gel reduced the erosion effect, while the nano-hydroxyapatite agent did not provide any protective effect.

  8. Efficacy of a casein phosphopeptide amorphous calcium phosphate (CPP-ACP) paste in preventing white spot lesions in patients with fixed orthodontic appliances: A prospective clinical trial.

    PubMed

    Esenlik, E; Uzer Çelik, E; Bolat, E

    2016-12-01

    The aim of this prospective study was to test the efficacy of casein phosphopeptide amorphous calcium phosphate (CPP-ACP) paste applied in-office to prevent white spot lesions (WSL) in patients undergoing fixed orthodontic treatment. Study design: this study was designed as a randomised controlled clinical trial. Fifty-seven patients undergoing nonextraction fixed orthodontic treatment were enrolled and divided randomly into two groups (control n = 28, experimental n = 29). The pretreatment plaque, gingival and bleeding indices, and oral hygiene habits were recorded. One group received CPP-ACP paste (GC Tooth Mousse) at each monthly orthodontic follow-up examination; the control group received routine orthodontic treatment. The mean patient age was 16.9 years in the experimental group and 17.1 years in the control group. The periodontal indices, decayed, missing, and filled teeth (DMFT), decayed, missing, and filled surfaces (DMFS), and the WSL prevalence pre- and post-treatment were measured and compared between the groups. differences between groups in normally distributed data between groups were assessed by the paired-t test, and the Wilcoxon Signed Rank test was used to compare variables that were not normally distributed. There was a lower incidence of WSL in the experimental group compared to the control group. Most of the WSL occurred at the maxillary incisors, mandibular canines and premolars. The in-office application of CPP-ACP paste did not prevent WSL development completely; however, it did significantly decrease the number of WSL compared to the control patients.

  9. Effect of the application of a casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste and adhesive systems on bond durability of a fissure sealant.

    PubMed

    Borges, Boniek Castillo Dutra; Catelan, Anderson; Sasaki, Robson Tetsuo; Ambrosano, Gláucia Maria Bovi; Reis, André Figueiredo; Aguiar, Flávio Henrique Baggio

    2013-01-01

    This study aimed to evaluate the effect of the previous application of a casein phosphopeptide-amorphous calcium phosphate paste (MI Paste, MI) and adhesive systems on the bond durability of a fissure sealant. Ninety-eight enamel blocks were obtained from proximal surfaces of erupted third molars. Specimens were divided into 14 groups (n = 7) according to the previous application of MI (with and without) and the adhesive systems used (no adhesive system; hydrophobic resin of a three-step etch-and-rinse adhesive system; etch-and-rinse single-bottle adhesive system; all-in-one adhesive system; two-step self-etching adhesive system; additional phosphoric acid conditioning and all-in-one adhesive system; additional phosphoric acid conditioning and two-step self-etching adhesive system). A fissure sealant (Fluroshield) was applied and photoactivated for 20 s. Beams (~0.7 mm(2)) were prepared for the microtensile bond strength test, which was executed after 24 h or 6 months of water storage. Fractured specimens were analyzed by scanning electronic microscopy. Data were analyzed by two-way ANOVA with repeated measures/Tukey's test (P < 0.05). Groups that received MI application and adhesive systems presented higher means than those groups where MI was not applied. Higher frequency of cohesive failures was observed for groups with MI. Applying a CPP-ACP containing paste on enamel before adhesive systems was an effective method to increase bond durability of the sealant tested.

  10. Temperature dependence, 0 to 40 deg. C, of the mineralogy of Portland cement paste in the presence of calcium carbonate

    SciTech Connect

    Matschei, Thomas; Glasser, Fredrik P.

    2010-05-15

    Thermodynamic calculations disclose that significant changes of the AFm and AFt phases and amount of Ca(OH){sub 2} occur between 0 and 40 deg. C; the changes are affected by added calcite. Hydrogarnet, C{sub 3}AH{sub 6}, is destabilised at low carbonate contents and/or low temperatures < 8 deg. C and is unlikely to form in calcite-saturated Portland cement compositions cured at < 40 deg. C. The AFm phase actually consists of several structurally-related compositions which form incomplete solid solutions. The AFt phase is close to its ideal stoichiometry at 25 deg. C but at low temperatures, < 20 deg. C, extensive solid solutions occur with CO{sub 3}-ettringite. A nomenclature scheme is proposed and AFm-AFt phase relations are presented in isothermal sections at 5, 25 and 40 deg. C. The AFt and AFm phase relations are depicted in terms of competition between OH, CO{sub 3} and SO{sub 4} for anion sites. Diagrams are presented showing how changing temperatures affect the volume of the solid phases with implications for space filling by the paste. Specimen calculations are related to regimes likely to occur in commercial cements and suggestions are made for testing thermal impacts on cement properties by defining four regimes. It is concluded that calculation provides a rapid and effective tool for exploring the response of cement systems to changing composition and temperature and to optimise cement performance.

  11. Electrochemical cell with calcium anode

    DOEpatents

    Cooper, John F.; Hosmer, Pamela K.; Kelly, Benjamin E.

    1979-01-01

    An electrochemical cell comprising a calcium anode and a suitable cathode in an alkaline electrolyte consisting essentially of an aqueous solution of an hydroxide and a chloride. Specifically disclosed is a mechanically rechargeable calcium/air fuel cell with an aqueous NaOH/NaCl electrolyte.

  12. Effectiveness of a calcium sodium phosphosilicate containing prophylaxis paste in reducing dentine hypersensitivity immediately and 4 weeks after a single application: a double-blind randomized controlled trial

    PubMed Central

    Neuhaus, Klaus W; Milleman, Jeffery L; Milleman, Kimberly R; Mongiello, Kimberly A; Simonton, Thomas C; Clark, Courtney E; Proskin, Howard M; Seemann, Rainer

    2013-01-01

    Aims The aim of this single-site, randomized, controlled, double-blind, 3-arm parallel study was to determine the effectiveness of a prophylaxis paste containing 15% calcium sodium phosphosilicate (CSPS; NovaMin®) with and without fluoride in reducing dentine hypersensitivity immediately after a single application and 28 days following dental scaling and root planing. Materials & Methods Overall, 151 subjects were enrolled in this study. All subjects received a scaling and root planing procedure followed by a final prophylaxis step using one of three different prophylaxis pastes: Test-A (15% NovaMin® and NaF), Test-B (15% NovaMin®) and a control. Dentine hypersensitivity was assessed by tactile stimulus (Yeaple Probe®) and by air blast (Schiff scale) at baseline, immediately after and 28 days after a prophylaxis procedure. One hundred and forty-nine subjects completed the study. Results Subjects having received the test prophylaxis pastes showed statistically lower (anova, p < 0.05) dentine hypersensitivity compared with the control group immediately after the prophylaxis procedure (Yeaple Probe®: Test-A = 20.9 ± 12.6, Test-B = 22.7 ± 12.9, Control=11.2 ± 3.1; Schiff score: Test-A = 1.1 ± 0.6, Test-B = 1.1 ± 0.6, Control = 2.0 ± 0.7) and after 28 days (Yeaple probe: Test-A = 21.5 ± 11.9, Test-B = 20.6 ± 11.3, Control = 11.8 ± 6.0; Schiff score: Test-A = 1.0 ± 0.6, Test-B = 1.0 ± 0.6, Control = 2.0 ± 0.7). Conclusions In conclusion, the single application of both fluoridated and non-fluoridated prophylaxis pastes containing 15% CSPS (NovaMin®) provided a significant reduction of dentine hypersensitivity up to at least 28 days. PMID:23414245

  13. Rice-husk ash paste and concrete: Some aspects of hydration and the microstructure of the interfacial zone between the aggregate and paste

    SciTech Connect

    Zhang, M.H.; Lastra, R.; Malhotra, V.M.

    1996-06-01

    This paper presents an experimental study on the effects of the incorporation of rice-husk ash (RHA) in cement paste and concrete on the hydration and the microstructure of the interfacial zone between the aggregate and paste. The influence on the compressive strength of concrete is discussed, and the results are compared with those obtained with the control portland cement concrete and concrete incorporating silica fume. As for ordinary portland cement paste, it was found that calcium hydroxide and calcium silicate hydrates [C-S-H] were the major hydration and reaction products for the HA paste. Because of the pozzolanic reaction, the paste incorporating RHA had lower Ca(OH){sub 2} content than the control portland cement paste. The incorporation of the RHA in concrete reduced its porosity and the Ca(OH){sub 2} amount in the interfacial zone; the width of the interfacial zone between the aggregate and the cement paste was also reduced compared with the control portland cement composite. However, the porosity in the interfacial zone of the rice-husk ash composite was higher than that of the silica fume composite. The incorporation of the RHA in the cement paste did not increase its compressive strength compared with that of the control. The higher compressive strength of the RHA concrete compared with that of the control is due probably to the reduced porosity, reduced Ca(OH){sub 2}, and reduced width of the interfacial zone between the paste and the aggregate.

  14. 21 CFR 184.1195 - Calcium citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... acid with calcium hydroxide or calcium carbonate. It occurs as a fine white, odorless powder and... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Calcium citrate. 184.1195 Section 184.1195 Food... Specific Substances Affirmed as GRAS § 184.1195 Calcium citrate. (a) Calcium citrate (Ca3(C6H5O7)2·4H2O...

  15. 21 CFR 184.1195 - Calcium citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... acid with calcium hydroxide or calcium carbonate. It occurs as a fine white, odorless powder and... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Calcium citrate. 184.1195 Section 184.1195 Food... Specific Substances Affirmed as GRAS § 184.1195 Calcium citrate. (a) Calcium citrate (Ca3(C6H5O7)2·4H2O...

  16. 21 CFR 184.1195 - Calcium citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... calcium hydroxide or calcium carbonate. It occurs as a fine white, odorless powder and usually contains... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium citrate. 184.1195 Section 184.1195 Food and... Substances Affirmed as GRAS § 184.1195 Calcium citrate. (a) Calcium citrate (Ca3(C6H5O7)2·4H2O, CAS Reg. No...

  17. 21 CFR 184.1195 - Calcium citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... acid with calcium hydroxide or calcium carbonate. It occurs as a fine white, odorless powder and... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Calcium citrate. 184.1195 Section 184.1195 Food... Specific Substances Affirmed as GRAS § 184.1195 Calcium citrate. (a) Calcium citrate (Ca3(C6H5O7)2·4H2O...

  18. Novel Injectable Calcium Phosphate Bone Cement from Wet Chemical Precipitation Method

    NASA Astrophysics Data System (ADS)

    Hablee, S.; Sopyan, I.; Mel, M.; Salleh, H. M.; Rahman, M. M.; Singh, R.

    2017-06-01

    Calcium phosphate cement has been prepared via chemical precipitation method for injectable bone filling materials. Calcium hydroxide, Ca(OH)2, and diammonium hydrogen phosphate, (NH4)2HPO4, were used as calcium and phosphorus precursors respectively. The synthesized powder was mixed with water at different powder-to-liquid (P/L) ratios, which was adjusted at 0.8, 0.9, 1.0, 1.1 and 1.2. The influence of P/L ratio on the injectability, setting time and mechanical strength of calcium phosphate cement paste has been evaluated. The synthesized powder appeared as purely hydroxyapatite with nanosized and agglomerated spherical particles. All cement pastes show excellent injectability except for the paste with P/L ratio 1.2. Calcium phosphate cement with P/L ratio 1.1 shows the ideal cement for bone filler application with good injectability, the initial and final setting times of 30 min and 160 min, and the compression strength of 2.47 MPa. The result indicated that the newly developed calcium phosphate cement is physically suitable for bone filler application. This paper presents our investigation on the effect of P/L ratio on the handling and mechanical properties of calcium phosphate cement prepared via wet chemical precipitation method.

  19. Immediate post-application effect of professional prophylaxis with 8% arginine-calcium carbonate desensitizing paste on hypersensitive teeth. A practitioner-based clinical trial.

    PubMed

    Chu, Chung-Hung; Lo, Edward Chin Man

    2014-02-01

    This practitioner-based clinical trial compared the pain reduction achieved by professional prophylaxis with 8% arginine calcium carbonate (CaCO3) desensitizing paste versus 5% potassium nitrate (KNO3) toothpaste on adult patients with tooth hypersensitivity. All dentists in Hong Kong were invited to join the study. Each participating dentist identified six adult patients with hypersensitive teeth after scaling in the clinic. For each patient, the most hypersensitive tooth was selected. Each hypersensitive tooth was isolated and tested with a blast of compressed cold air delivered from a three-in-one syringe. The patient was then asked to indicate a sensitivity score (SS) from 0 to 10. Three patients received professional prophylaxis with 8% arginine CaCO3 desensitizing paste (Group 1), and the other three received prophylaxis with desensitizing toothpaste containing 5% KNO3 and 1,450 ppm fluoride (Group 2). The teeth were tested for a second time with compressed cold air, and the patients were asked to report the SS again. A non-parametric test was used to analyze the results following a normality test of the SS. A total of 303 patients were recruited by 65 participating dentists. The mean age of the patients was 40.1, and 59% were female. The median pre-treatment SS of Groups 1 and 2 were both 7, whereas the post-treatment SS were 3 and 4, respectively (P < 0.001). The median percentage reductions in sensitivity scores of Groups 1 and 2 were 57.14% and 38.75%, respectively (P < 0.001).

  20. The effect of casein phosphopeptide-amorphous calcium phosphate paste and sodium fluoride mouthwash on the prevention of dentine erosion: An in vitro study

    PubMed Central

    Moezizadeh, Maryam; Alimi, Azar

    2014-01-01

    Aim: The purpose was to compare the effect of 0.2% sodium fluoride mouthwash and casein phosphopeptide-amorphous calcium phosphate paste on prevention of dentin erosion. Materials and Methods: Buccal surfaces of 36 sound premolar teeth were ground flat and polished with abrasive discs. Half the polished surfaces were covered with tape to maintain a reference surface. Samples were randomly allocated into three groups. Group A was pretreated with tooth mousse (TM) 4 times a day for 5 days. Group B was pretreated with 0.2% sodium fluoride mouthwash 4 times a day for 5 days. Group C was considered as the control group with no pretreatment. In the next step, the samples were exposed to Coca-Cola 4 times a day for 3 days. After each erosive cycle, the samples were rinsed with deionized water and stored in artificial saliva. The surface loss was determined using profilometry. Results: The erosion in both Groups A and B was less than the control group. The surface loss in mouthwash group was significantly lower than in the control group. Erosion in TM group was more than the mouthwash group and less than the control group. Conclusion: Sodium fluoride mouthwash is more effective for prevention of dentin erosion. PMID:24944448

  1. Evaluation of triple antibiotic paste removal by different irrigation procedures.

    PubMed

    Berkhoff, Julie A; Chen, Paul B; Teixeira, Fabricio B; Diogenes, Anibal

    2014-08-01

    Regenerative endodontics aims to re-establish a functional pulp-dentin complex. First, the root canal system is disinfected primarily by irrigants and medicaments. Triple antibiotic paste (TAP), a commonly used intracanal medicament, has been shown to be directly toxic to stem cells at concentrations greater than 0.1 g/mL. Thus, its complete removal is a crucial step in regenerative endodontic procedures. We hypothesized that currently used irrigation techniques do not completely remove TAP from root canal system. TAP was radiolabeled by the incorporation of I(125), and calcium hydroxide (Ultracal; Ultradent, South Jordan, UT) was radiolabeled with Ca(45). The intracanal medicaments were placed into standardized human root segments and incubated for 28 days at 37°C. Then, canals were irrigated with EndoActivator (Dentsply, Tulsa, OK), passive ultrasonic irrigation, EndoVac (SybronEndo, Coppell, TX), or a syringe/Max-i-Probe needle (Dentsply Rinn, Elgin, IL) using a standardized irrigation protocol in a closed system. Radioactivity levels (counts per minute values) were measured for each tooth before and after the irrigation protocols. Furthermore, the canals were sequentially enlarged and dentin samples collected and evaluated for radioactivity. Data were analyzed with analysis of variance and Bonferroni post hoc testing (P < .05). Approximately 88% of the TAP was retained in the root canal system regardless of the irrigation technique used (no difference among groups). Furthermore, approximately 50% of the radiolabeled TAP was present circumferentially up to 350 μm within the dentin. Conversely, up to 98% of the radiolabeled intracanal calcium hydroxide was removed, and most residual medicament was found present in the initial 50 μm of dentin. Current irrigation techniques do not effectively remove TAP from root canal systems, possibly because of its penetration and binding into dentin. However, calcium hydroxide is effectively removed with significant less

  2. Hydroxide-catalyzed bonding

    NASA Technical Reports Server (NTRS)

    Gwo, Dz-Hung (Inventor)

    2003-01-01

    A method of bonding substrates by hydroxide-catalyzed hydration/dehydration involves applying a bonding material to at least one surface to be bonded, and placing the at least one surface sufficiently close to another surface such that a bonding interface is formed between them. A bonding material of the invention comprises a source of hydroxide ions, and may optionally include a silicate component, a particulate filling material, and a property-modifying component. Bonding methods of the invention reliably and reproducibly provide bonds which are strong and precise, and which may be tailored according to a wide range of possible applications. Possible applications for bonding materials of the invention include: forming composite materials, coating substrates, forming laminate structures, assembly of precision optical components, and preparing objects of defined geometry and composition. Bonding materials and methods of preparing the same are also disclosed.

  3. Efficacy of two calcium phosphate pastes on the remineralization of artificial caries: a randomized controlled double-blind in situ study

    PubMed Central

    Vanichvatana, Somkamol; Auychai, Prim

    2013-01-01

    To test the efficacy of two calcium phosphate pastes compared to that of fluoride toothpaste on remineralizing artificial caries in situ, this study had a double-blind crossover in situ design, involving three experimental phases of 14 days each, with an 8-day washout period between phases. Nine healthy subjects participated in the study. The subjects wore removable palatal appliances mounted with six human enamel slabs with artificial caries lesions, and in each of the experimental phases, used one of the following methods two times/day: group A, brushing with 1.0 g of Colgate Regular Flavor, followed by applying 0.25 g of Tooth Mousse Plus; group B, brushing with 0.25 g of Clinpro Tooth Crème; and group C, brushing with 1.0 g of Colgate Regular Flavor. After 14 days, the enamel slabs (54 slabs/group) were embedded in resin, sectioned and examined with a polarized-light microscope, and the lesion areas were quantified using Image-Pro Plus. All experimental groups showed a significant reduction in lesion area compared to the initial lesion area (paired t-test, P<0.001). The mean reduction in lesion area of Groups A, B and C were (0.029±0.010), (0.030±0.009) and (0.027±0.009) mm2, respectively. There were no statistical differences between groups (Kruskal–Wallis test, P>0.05). All three groups remineralized the enamel slab lesions, indicating model sensitivity to fluoride. Given the differences in usage amounts and treated regimens, Clinpro Tooth Crème provided similar benefits to the fluoride toothpaste; however, no additional benefit of Tooth Mousse Plus was observed when used in conjunction with the fluoride toothpaste. PMID:24030557

  4. Double layered hydroxides as potential anti-cancer drug delivery agents.

    PubMed

    Riaz, Ufana; Ashraf, S M

    2013-04-01

    The emergence of nanotechnology has changed the scenario of the medical world by revolutionizing the diagnosis, monitoring and treatment of cancer. This nanotechnology has been proved miraculous in detecting cancer cells, delivering chemotherapeutic agents and monitoring treatment from non-specific to highly targeted killing of tumor cells. In the past few decades, a number of inorganic materials have been investigated such as calcium phosphate, gold, carbon materials, silicon oxide, iron oxide, and layered double hydroxide (LDH) for examining their efficacy in targeting drug delivery. The reason behind the selection of these inorganic materials was their versatile and unique features efficient in drug delivery, such as wide availability, rich surface functionality, good biocompatibility, potential for target delivery, and controlled release of the drug from these inorganic nanomaterials. Although, the drug-LDH hybrids are found to be quite instrumental because of their application as advanced anti-cancer drug delivery systems, there has not been much research on them. This mini review is set to highlight the advancement made in the use of layered double hydroxides (LDHs) as anti-cancer drug delivery agents. Along with the advantages of LDHs as anti-cancer drug delivery agents, the process of interaction of some of the common anti-cancer drugs with LDH has also been discussed.

  5. Novel synthesis of layered double hydroxides (LDHs) from zinc hydroxide

    NASA Astrophysics Data System (ADS)

    Meng, Zilin; Zhang, Yihe; Zhang, Qian; Chen, Xue; Liu, Leipeng; Komarneni, Sridhar; Lv, Fengzhu

    2017-02-01

    The most common synthesis methods for layered double hydroxides (LDHs) are co-precipitation and reconstruction, which can have some limitations for application. Here, we report a novel synthesis method for LDHs. We use zinc hydroxide as the precursor to synthesize LDHs phase through a simple transformation process of zinc hydroxide phase. For this transformation process, aluminum can enter into zinc hydroxide and replace zinc quickly to transform it into LDH by creating positive charges in the zinc hydroxide solid phase. The mechanism of LDH formation was through Al3+ reaction first with zinc hydroxide followed by recrystallization of the original structure of zinc hydroxide. Thus, the new process of LDH formation involves a reaction of Al to substitute for Zn and recrystallization leading to LDH and the final pH influences the crystallization of LDHs by this process. In addition, Cr3+ was employed as a trivalent cation for LDH formation to react with zinc hydroxide, which also led to LDH structure.

  6. Study on Utilization of Carboxyl Group Decorated Carbon Nanotubes and Carbonation Reaction for Improving Strengths and Microstructures of Cement Paste

    PubMed Central

    Yan, Xiantong; Cui, Hongzhi; Qin, Qinghua; Tang, Waiching; Zhou, Xiangming

    2016-01-01

    Carbon nanotubes (CNTs) have excellent mechanical properties and can be used to reinforce cement-based materials. On the other hand, the reaction product of carbonation with hydroxides in hydrated cement paste can reduce the porosity of cement-based materials. In this study, a novel method to improve the strength of cement paste was developed through a synergy of carbon nanotubes decorated with carboxyl group and carbonation reactions. The experimental results showed that the carboxyl group (–COOH) of decorated carbon nanotubes and the surfactant can control the morphology of the calcium carbonate crystal of carbonation products in hydrated cement paste. The spindle-like calcium carbonate crystals showed great morphological differences from those observed in the conventional carbonation of cement paste. The spindle-like calcium carbonate crystals can serve as fiber-like reinforcements to reinforce the cement paste. By the synergy of the carbon nanotubes and carbonation reactions, the compressive and flexural strengths of cement paste were significantly improved and increased by 14% and 55%, respectively, when compared to those of plain cement paste. PMID:28335281

  7. Study on Utilization of Carboxyl Group Decorated Carbon Nanotubes and Carbonation Reaction for Improving Strengths and Microstructures of Cement Paste.

    PubMed

    Yan, Xiantong; Cui, Hongzhi; Qin, Qinghua; Tang, Waiching; Zhou, Xiangming

    2016-08-19

    Carbon nanotubes (CNTs) have excellent mechanical properties and can be used to reinforce cement-based materials. On the other hand, the reaction product of carbonation with hydroxides in hydrated cement paste can reduce the porosity of cement-based materials. In this study, a novel method to improve the strength of cement paste was developed through a synergy of carbon nanotubes decorated with carboxyl group and carbonation reactions. The experimental results showed that the carboxyl group (-COOH) of decorated carbon nanotubes and the surfactant can control the morphology of the calcium carbonate crystal of carbonation products in hydrated cement paste. The spindle-like calcium carbonate crystals showed great morphological differences from those observed in the conventional carbonation of cement paste. The spindle-like calcium carbonate crystals can serve as fiber-like reinforcements to reinforce the cement paste. By the synergy of the carbon nanotubes and carbonation reactions, the compressive and flexural strengths of cement paste were significantly improved and increased by 14% and 55%, respectively, when compared to those of plain cement paste.

  8. Arsenic fixation on iron-hydroxide-rich and plant litter-containing sediments in natural environments

    NASA Astrophysics Data System (ADS)

    Fritzsche, Andreas; Dienemann, Holger; Dudel, Ernst Gert

    2006-10-01

    Iron-hydroxide-rich and plant litter-containing sediments from natural sites contaminated with uranium mine tailing leachates were examined for their ability to adsorb arsenic. The samples with high contents of iron hydroxides (Fetotal concentration, >300 g kg-1) exhibited remarkable fixation of arsenic (up to 40 g As kg-1). This value corresponded approximately to the supersaturation point for natural iron hydroxides under the present conditions, and it was significantly lower than the value found for synthetic iron hydroxides. There was a strong correlation ( R=0.8999) between the concentration of iron and that of arsenic at low arsenic contents, indicating adsorption on strong binding sites. Although all the samples had noticeable contents of organic carbon (plant litter), calcium, and manganese, no obvious effect of these elements on arsenic fixation could be detected. The amount of iron hydroxides was found the only fixation-controlling parameter immediately below a leaching water source.

  9. The effects of lithium hydroxide solution on alkali silica reaction gels created with opal

    SciTech Connect

    Mitchell, Lyndon D.; Beaudoin, James J.; Grattan-Bellew, Patrick

    2004-04-01

    The reaction of Nevada opal with calcium hydroxide, potassium hydroxide and lithium hydroxide solutions was investigated. In addition, opal was exposed to a combined solution of these three hydroxides. The progress of the three reactions was followed using X-ray diffraction (XRD), {sup 29}Si nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM). The XRD results indicated the presence of a low-angle peak exclusive to the lithium-based reactions. The NMR results suggested a change in the silicate structure in the presence of lithium. These techniques indicated that the reaction of the alkali with the opal starting material is inhibited and perhaps stopped in the presence of lithium hydroxide. SEM revealed that the morphology of the reaction products on the surface of the reacted opal grains is markedly different invariably. It was concluded that evidence to support the theory of a protective layer exists and that the nature of the layer varies with ion type.

  10. Characterisation of cement pastes by inverse gas chromatography.

    PubMed

    Oliva, Victor; Mrabet, Béchir; Baeta Neves, Maria Inês; Chehimi, Mohamed M; Benzarti, Karim

    2002-09-06

    Two cement pastes, commonly used in concrete formulations, were characterised by IGC at 35-80 degrees C before and after coating with an epoxy resin and a hardener. The cements are mixtures of hydrates in various proportions, such as calcium silicate hydrate (CaO-SiO2-H2O) and calcium hydroxide Ca(OH)2. Apolar and polar probes were used to determine the dispersive and acid-base characteristics of the cement pastes. These materials have high surface energy as judged from the dispersive contribution to the surface free energy (gamma(s)d) values lying in the 50-70 mJ/m2 range at 60-80 degrees C. Examination of the specific interactions permitted to show that the cement pastes are strongly amphoteric species with a substantial predominant Lewis basicity that is in line with the basic pH of their aqueous suspensions. Following coating with an epoxy resin (DGEBA) and a hardener (triethylene tetramine), the surface energy of the cements decreases substantially with the mass loading of the organic material. The surface thermodynamic properties were also correlated with the surface chemical composition as determined by X-ray photoelectron spectroscopy.

  11. A study of the electrochemistry of nickel hydroxide electrodes with various additives

    NASA Astrophysics Data System (ADS)

    Zhu, Wen-Hua; Ke, Jia-Jun; Yu, Hong-Mei; Zhang, Deng-Jun

    Nickel composite electrodes (NCE) with various additives are prepared by a chemical impregnation method from nitrate solutions on sintered porous plaques. The electrochemical properties, such as utilization of active material, swelling and the discharge potential of the nickel oxide electrode (NOE) are determined mainly through the composition of the active material and the characteristics of nickel plaques. Most additives (Mg, Ca, Sr, Ba, Zn, Cd, Co, Li and Al hydroxide) exert effects on the discharge potential and swelling of the NOE. Chemical co-precipitation with the addition of calcium, zinc, magnesium and barium hydroxide increases the discharge potential by more than 20 mV, but that with zinc hydroxide results in an obvious decrease of active-material utilization and that with calcium and magnesium hydroxide produces a larger increase of electrode thickness. The effects of anion additives are also examined. Less than 1% mol of NiS in the active material increases the discharge potential. Cadmium, cobalt and zinc hydroxide are excellent additives for preventing swelling of the NCE. Slow voltammetry (0.2 mV s -1) in 6 M KOH is applied to characterize the oxygen-evolving potential of the NCE. The difference between the oxygen-evolution potential and the potential of the oxidation peak for the NCE with additives of calcium, lithium, barium and aluminium hydroxide is at least + 60 mV.

  12. 21 CFR 184.1631 - Potassium hydroxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium hydroxide. 184.1631 Section 184.1631... Listing of Specific Substances Affirmed as GRAS § 184.1631 Potassium hydroxide. (a) Potassium hydroxide..., including pellets, flakes, sticks, lumps, and powders. Potassium hydroxide is obtained commercially from the...

  13. 21 CFR 184.1631 - Potassium hydroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium hydroxide. 184.1631 Section 184.1631... GRAS § 184.1631 Potassium hydroxide. (a) Potassium hydroxide (KOH, CAS Reg. No. 1310-58-3) is also... powders. Potassium hydroxide is obtained commercially from the electrolysis of potassium chloride solution...

  14. 21 CFR 184.1631 - Potassium hydroxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium hydroxide. 184.1631 Section 184.1631... Listing of Specific Substances Affirmed as GRAS § 184.1631 Potassium hydroxide. (a) Potassium hydroxide..., including pellets, flakes, sticks, lumps, and powders. Potassium hydroxide is obtained commercially from the...

  15. 21 CFR 184.1631 - Potassium hydroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium hydroxide. 184.1631 Section 184.1631 Food... Specific Substances Affirmed as GRAS § 184.1631 Potassium hydroxide. (a) Potassium hydroxide (KOH, CAS Reg... pellets, flakes, sticks, lumps, and powders. Potassium hydroxide is obtained commercially from the...

  16. 21 CFR 184.1631 - Potassium hydroxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Potassium hydroxide. 184.1631 Section 184.1631... Listing of Specific Substances Affirmed as GRAS § 184.1631 Potassium hydroxide. (a) Potassium hydroxide..., including pellets, flakes, sticks, lumps, and powders. Potassium hydroxide is obtained commercially from the...

  17. Cobalt improves nickel hydroxide electrodes for batteries

    NASA Technical Reports Server (NTRS)

    Lerner, S. R.; Seiger, H. N.

    1969-01-01

    Positive nickel hydroxide electrodes containing 20 mole percent of cobalt hydroxide are more efficient than when impregnated to the same degree by weight with nickel hydroxide alone. Charge-acceptance and oxygen-evolution tests indicate cobalt electrodes are more efficient than plain positive nickel hydroxide electrodes at all rates of charge.

  18. 21 CFR 184.1428 - Magnesium hydroxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Magnesium hydroxide. 184.1428 Section 184.1428... Listing of Specific Substances Affirmed as GRAS § 184.1428 Magnesium hydroxide. (a) Magnesium hydroxide... is prepared as a white precipitate by the addition of sodium hydroxide to a water soluble magnesium...

  19. 21 CFR 184.1428 - Magnesium hydroxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Magnesium hydroxide. 184.1428 Section 184.1428... Listing of Specific Substances Affirmed as GRAS § 184.1428 Magnesium hydroxide. (a) Magnesium hydroxide... is prepared as a white precipitate by the addition of sodium hydroxide to a water soluble magnesium...

  20. Hydroxide catalysts for lignin depolymerization

    DOEpatents

    Beckham, Gregg T.; Biddy, Mary J.; Chmely, Stephen C.; Sturgeon, Matthew

    2017-04-25

    Solid base catalysts and their use for the base-catalyzed depolymerization (BCD) of lignin to compounds such as aromatics are presented herein. Exemplary catalysts include layered double hydroxides (LDHs) as recyclable, heterogeneous catalysts for BCD of lignin.

  1. Computational Material Modeling of Hydrated Cement Paste Calcium Silicate Hydrate (C-S-H) Chemistry Structure - Influence of Magnesium Exchange on Mechanical Stiffness: C-S-H Jennite

    DTIC Science & Technology

    2015-04-27

    material chemistry structure are studied following a molecular dynamics (MD) computational modeling methodology. Calcium ions are replaced with... chemistry structure. Conference Name: 1st Pan-American Conference on Computational Mechanics Conference Date: April 27, 2015 1st Pan-American Congress on...MODELING OF C-S-H Material chemistry level modeling following the principles and techniques commonly grouped under Computational Material Science is

  2. Advances in aluminum hydroxide-based adjuvant research and its mechanism.

    PubMed

    He, Peng; Zou, Yening; Hu, Zhongyu

    2015-01-01

    In the past few decades, hundreds of materials have been tried as adjuvant; however, only aluminum-based adjuvants continue to be used widely in the world. Aluminum hydroxide, aluminum phosphate and alum constitute the main forms of aluminum used as adjuvants. Among these, aluminum hydroxide is the most commonly used chemical as adjuvant. In spite of its wide spread use, surprisingly, the mechanism of how aluminum hydroxide-based adjuvants exert their beneficial effects is still not fully understood. Current explanations for the mode of action of aluminum hydroxide-based adjuvants include, among others, the repository effect, pro-phagocytic effect, and activation of the pro-inflammatory NLRP3 pathway. These collectively galvanize innate as well as acquired immune responses and activate the complement system. Factors that have a profound influence on responses evoked by aluminum hydroxide-based adjuvant applications include adsorption rate, strength of the adsorption, size and uniformity of aluminum hydroxide particles, dosage of adjuvant, and the nature of antigens. Although vaccines containing aluminum hydroxide-based adjuvants are beneficial, sometimes they cause adverse reactions. Further, these vaccines cannot be stored frozen. Until recently, aluminum hydroxide-based adjuvants were known to preferentially prime Th2-type immune responses. However, results of more recent studies show that depending on the vaccination route, aluminum hydroxide-based adjuvants can enhance both Th1 as well as Th2 cellular responses. Advances in systems biology have opened up new avenues for studying mechanisms of aluminum hydroxide-based adjuvants. These will assist in scaling new frontiers in aluminum hydroxide-based adjuvant research that include improvement of formulations, use of nanoparticles of aluminum hydroxide and development of composite adjuvants.

  3. Advances in aluminum hydroxide-based adjuvant research and its mechanism

    PubMed Central

    He, Peng; Zou, Yening; Hu, Zhongyu

    2015-01-01

    In the past few decades, hundreds of materials have been tried as adjuvant; however, only aluminum-based adjuvants continue to be used widely in the world. Aluminum hydroxide, aluminum phosphate and alum constitute the main forms of aluminum used as adjuvants. Among these, aluminum hydroxide is the most commonly used chemical as adjuvant. In spite of its wide spread use, surprisingly, the mechanism of how aluminum hydroxide-based adjuvants exert their beneficial effects is still not fully understood. Current explanations for the mode of action of aluminum hydroxide-based adjuvants include, among others, the repository effect, pro-phagocytic effect, and activation of the pro-inflammatory NLRP3 pathway. These collectively galvanize innate as well as acquired immune responses and activate the complement system. Factors that have a profound influence on responses evoked by aluminum hydroxide-based adjuvant applications include adsorption rate, strength of the adsorption, size and uniformity of aluminum hydroxide particles, dosage of adjuvant, and the nature of antigens. Although vaccines containing aluminum hydroxide-based adjuvants are beneficial, sometimes they cause adverse reactions. Further, these vaccines cannot be stored frozen. Until recently, aluminum hydroxide-based adjuvants were known to preferentially prime Th2-type immune responses. However, results of more recent studies show that depending on the vaccination route, aluminum hydroxide-based adjuvants can enhance both Th1 as well as Th2 cellular responses. Advances in systems biology have opened up new avenues for studying mechanisms of aluminum hydroxide-based adjuvants. These will assist in scaling new frontiers in aluminum hydroxide-based adjuvant research that include improvement of formulations, use of nanoparticles of aluminum hydroxide and development of composite adjuvants. PMID:25692535

  4. Atomic force microscopic comparison of remineralization with casein-phosphopeptide amorphous calcium phosphate paste, acidulated phosphate fluoride gel and iron supplement in primary and permanent teeth: An in-vitro study

    PubMed Central

    Agrawal, Nikita; Shashikiran, N. D.; Singla, Shilpy; Ravi, K. S.; Kulkarni, Vinaya Kumar

    2014-01-01

    Context: Demineralization of tooth by erosion is caused by frequent contact between the tooth surface and acids present in soft drinks. Aim: The present study objective was to evaluate the remineralization potential of casein-phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste, 1.23% acidulated phosphate fluoride (APF) gel and iron supplement on dental erosion by soft drinks in human primary and permanent enamel using atomic force microscopy (AFM). Materials and Methods: Specimens were made from extracted 15 primary and 15 permanent teeth which were randomly divided into three treatment groups: CPP-ACP paste, APF gel and iron supplement. AFM was used for baseline readings followed by demineralization and remineralization cycle. Results and Statistics: Almost all group of samples showed remineralization that is a reduction in surface roughness which was higher with CPP-ACP paste. Statistical analysis was performed using by one-way ANOVA and Mann-Whitney U-test with P < 0.05. Conclusions: It can be concluded that the application of CPP-ACP paste is effective on preventing dental erosion from soft drinks. PMID:24808700

  5. Atomic force microscopic comparison of remineralization with casein-phosphopeptide amorphous calcium phosphate paste, acidulated phosphate fluoride gel and iron supplement in primary and permanent teeth: An in-vitro study.

    PubMed

    Agrawal, Nikita; Shashikiran, N D; Singla, Shilpy; Ravi, K S; Kulkarni, Vinaya Kumar

    2014-01-01

    Demineralization of tooth by erosion is caused by frequent contact between the tooth surface and acids present in soft drinks. The present study objective was to evaluate the remineralization potential of casein-phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste, 1.23% acidulated phosphate fluoride (APF) gel and iron supplement on dental erosion by soft drinks in human primary and permanent enamel using atomic force microscopy (AFM). Specimens were made from extracted 15 primary and 15 permanent teeth which were randomly divided into three treatment groups: CPP-ACP paste, APF gel and iron supplement. AFM was used for baseline readings followed by demineralization and remineralization cycle. Almost all group of samples showed remineralization that is a reduction in surface roughness which was higher with CPP-ACP paste. Statistical analysis was performed using by one-way ANOVA and Mann-Whitney U-test with P < 0.05. It can be concluded that the application of CPP-ACP paste is effective on preventing dental erosion from soft drinks.

  6. Sulfur dioxide removal process with gypsum and magnesium hydroxide production

    SciTech Connect

    College, J.W.; Benson, L.B.

    1992-01-28

    This patent describes improvement in a method for removing sulfur dioxide from flue gases wherein the flue gases are contacted in a wet scrubbing unit, in the absence of any substantial amount of calcium components, with an aqueous solution of magnesium components and magnesium sulfite produced, with aqueous solution, following the contact, collected and recycled to the wet scrubber for further contact with flue gases, and subjecting a portion of the aqueous discharge from the scrubbing unit, containing magnesium sulfite, to oxidation in an oxidation unit. The improvement comprises: adding calcium sulfate to the portion of aqueous discharge containing magnesium sulfite prior to oxidation in the oxidation unit to form an oxidized aqueous effluent containing calcium sulfate solids and dissolved magnesium sulfate; passing the oxidized aqueous effluent to a regeneration tank; adding lime to the regeneration tank to precipitate gypsum from and form an aqueous magnesium hydroxide suspension in the oxidized aqueous effluent; separating the precipitated gypsum from the aqueous magnesium hydroxide suspension; and returning at least a portion of the separated precipitated gypsum to the oxidizing unit as the added calcium sulfate.

  7. Calcium supplements

    MedlinePlus

    ... TYPES OF CALCIUM SUPPLEMENTS Forms of calcium include: Calcium carbonate: Over-the-counter (OTC) antacid products, such as Tums and Rolaids, contain calcium carbonate. These sources of calcium do not cost much. ...

  8. Reactivity of NO2 and CO2 with hardened cement paste containing activated carbon

    NASA Astrophysics Data System (ADS)

    Horgnies, M.; Dubois-Brugger, I.; Krou, N. J.; Batonneau-Gener, I.; Belin, T.; Mignard, S.

    2015-07-01

    The development of building materials to reduce the concentration of NO2 is growing interest in a world where the air quality in urban areas is affected by the car traffic. The main binder in concrete is the cement paste that is partly composed of calcium hydroxide. This alkaline hydrate composing the hardened cement paste shows a high BET surface area (close to 100 m2.g-1) and can absorb low-concentrations of NO2. However, the presence of CO2 in the atmosphere limits the de-polluting effect of reference cement paste, mainly due to carbonation of the alkaline hydrates (reaction leading to the formation of calcium carbonate). The results established in this paper demonstrate that the addition of activated carbon in the cement paste, because of its very high BET surface area (close to 800 m2.g-1) and its specific reactivity with NO2, can significantly improve and prolong the de-polluting effect in presence of CO2 and even after complete carbonation of the surface of the cement paste.

  9. A Case of Recurrent Renal Aluminum Hydroxide Stone

    PubMed Central

    Cakıroglu, Basri; Dogan, Akif Nuri; Tas, Tuncay; Gozukucuk, Ramazan; Uyanik, Bekir Sami

    2014-01-01

    Renal stone disease is characterized by the differences depending on the age, gender, and the geographic location of the patients. Seventy-five percent of the renal stone components is the calcium (Ca). The most common type of the stones is the Ca oxalate stones, while Ca phosphate, uric acid, struvite, and sistine stones are more rarely reported. Other than these types, triamterene, adenosine, silica, indinavir, and ephedrine stones are also reported in the literature as case reports. However, to the best of our knowledge, aluminum hydroxide stones was not reported reported before. Herein we will report a 38-years-old woman with the history of recurrent renal colic disease whose renal stone was determined as aluminum hydroxide stone in type. Aluminum mineral may be considered in the formation of kidney stones as it is widely used in the field of healthcare and cosmetics. PMID:25013740

  10. The effect of casein phosphopeptide amorphous calcium phosphate fluoride paste (CPP-ACPF) on oral and salivary conditions of patients undergoing chemotherapy: A randomized controlled clinical trial

    PubMed Central

    Banava, Sepideh; Houshyari, Mohammad; Safaie, Tahmineh

    2015-01-01

    Background Oral and saliva conditions of patients undergoing chemotherapy is often affected by the medication they receive. Up to now, no appropriate medication that possesses the positive effects of chemotherapy without presenting oral complications has been introduced. Objective The aim of this study was to assess the clinical effects of CPP-ACPF paste on the oral and salivary status of patients undergoing chemotherapy. Methods From October 2013 to April 2014, 20 patients in chemotherapy treatment plans and who met the inclusion criteria enrolled in this randomized parallel single-blind controlled clinical trial in Shohada-e-Tajrish Hospital in Tehran, Iran. Patients were divided into two groups: 1) patients received their daily medication of cancer therapy center (group 1, control); 2) patients applied CPP-ACPF Crème (MI paste plus, GC USA) twice a day as instructed (group 2). The baseline status of oral conditions of patients (mucositis, dry mouth, infection, diminished tasting sense, difficulty in food intake, burning sensation of mucosa, saliva and dental plaque pH, rest and stimulated saliva, buffering capacity of saliva) were recorded and reevaluated after 21 and 42 days. The data were analyzed with a Mann-Whitney U-test. Results A total of 20 patients were allocated randomly to groups 1 and 2. The Mann-Whitney U-test showed that application of CPP-ACPF paste twice daily did not cause any significant difference in oral complication of the subject group compared with the control group (p>0.05). Among salivary signs, resting and stimulated saliva rates and saliva buffering capacity had significantly altered in the CPP-ACPF group in day 21 and 42 in comparison with those of the control group (p<0.05). Conclusion Application of CPP-ACPF paste before and during chemotherapy can improve the salivary status of patients undergoing this treatment. PMID:26767110

  11. Effect of dentin pre-treatment with a casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste on dentin bond strength in tridimensional cavities.

    PubMed

    Borges, Boniek Castillo Dutra; Souza-Junior, Eduardo Jose; da Costa, Giovanna de Fátima Alves; Pinheiro, Isauremi Vieira de Assunçao; Sinhoreti, Mário Alexandre Coelho; Braz, Rodivan; Montes, Marcos Antônio Japiassú Resende

    2013-01-01

    This study aimed to evaluate the push-out bond strength of dimethacrylate (Clearfil SE Bond/Filtek Z250; and Adper SE Plus/Filtek Z250) and silorane-based (Filtek P90 adhesive system/Filtek P90 composite resin) restorative systems following selective dentin pre-treatment with a CPP-ACP-containing paste (MI Paste). Sixty bovine incisors were utilized. The buccal surface was wet-ground to obtain a flat dentin area. Standardized conical cavities were then prepared. Adhesive systems were applied according to manufacturers' directions and the composites were bulk-inserted into the cavity. The push-out bond strength test was performed at a universal testing machine (0.5 mm/min) until failure; failure modes were analyzed by scanning electron microscopy. Data were analyzed by two-way ANOVA and Tukey post-hoc test (p < 0.05). For Clearfil SE Bond/Filtek Z250 and Filtek P90 adhesive system/Filtek P90 composite resin, the dentin pre-treatment did not influence bond strength means. For Adper SE Plus/Filtek Z250, dentin samples treated with MI Paste had statistically higher bond strength means than non-treated specimens. Adhesive failures were more frequent. Dentin pre-treatment with the CPP-ACP containing paste did not negatively affect bond strength for Clearfil SE Bond/Filtek Z250 and Filtek P90 adhesive system/Filtek P90 composite resin restorative systems and improved bond strength for the Adper SE Plus/Filtek Z250 restorative system.

  12. 21 CFR 582.1139 - Ammonium hydroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Additives § 582.1139 Ammonium hydroxide. (a) Product. Ammonium hydroxide. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or feeding...

  13. 21 CFR 582.1763 - Sodium hydroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Additives § 582.1763 Sodium hydroxide. (a) Product. Sodium hydroxide. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or feeding practice. ...

  14. Stretch-activated calcium channels relay fast calcium waves propagated by calcium-induced calcium influx.

    PubMed

    Jaffe, Lionel F

    2007-03-01

    For nearly 30 years, fast calcium waves have been attributed to a regenerative process propagated by CICR (calcium-induced calcium release) from the endoplasmic reticulum. Here, I propose a model containing a new subclass of fast calcium waves which is propagated by CICI (calcium-induced calcium influx) through the plasma membrane. They are called fast CICI waves. These move at the order of 100 to 1000 microm/s (at 20 degrees C), rather than the order of 3 to 30 microm/s found for CICR. Moreover, in this proposed subclass, the calcium influx which drives calcium waves is relayed by stretch-activated calcium channels. This model is based upon reports from approx. 60 various systems. In seven of these reports, calcium waves were imaged, and, in five of these, evidence was presented that these waves were regenerated by CICI. Much of this model involves waves that move along functioning flagella and cilia. In these systems, waves of local calcium influx are thought to cause waves of local contraction by inducing the sliding of dynein or of kinesin past tubulin microtubules. Other cells which are reported to exhibit waves, which move at speeds in the fast CICI range, include ones from a dozen protozoa, three polychaete worms, three molluscs, a bryozoan, two sea urchins, one arthropod, four insects, Amphioxus, frogs, two fish and a vascular plant (Equisetum), together with numerous healthy, as well as cancerous, mammalian cells, including ones from human. In two of these systems, very gentle local mechanical stimulation is reported to initiate waves. In these non-flagellar systems, the calcium influxes are thought to speed the sliding of actinomyosin filaments past each other. Finally, I propose that this mechanochemical model could be tested by seeing if gentle mechanical stimulation induces waves in more of these systems and, more importantly, by imaging the predicted calcium waves in more of them.

  15. 21 CFR 582.1631 - Potassium hydroxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium hydroxide. 582.1631 Section 582.1631 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1631 Potassium hydroxide. (a) Product. Potassium hydroxide. (b) Conditions of use. This...

  16. 21 CFR 582.1631 - Potassium hydroxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Potassium hydroxide. 582.1631 Section 582.1631 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1631 Potassium hydroxide. (a) Product. Potassium hydroxide. (b) Conditions of use. This...

  17. 21 CFR 582.1631 - Potassium hydroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium hydroxide. 582.1631 Section 582.1631 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1631 Potassium hydroxide. (a) Product. Potassium hydroxide. (b) Conditions of use. This...

  18. 21 CFR 582.1631 - Potassium hydroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium hydroxide. 582.1631 Section 582.1631 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1631 Potassium hydroxide. (a) Product. Potassium hydroxide. (b) Conditions of use. This...

  19. 21 CFR 582.1631 - Potassium hydroxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Potassium hydroxide. 582.1631 Section 582.1631 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1631 Potassium hydroxide. (a) Product. Potassium hydroxide. (b) Conditions of use. This...

  20. 21 CFR 582.1428 - Magnesium hydroxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Magnesium hydroxide. 582.1428 Section 582.1428 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1428 Magnesium hydroxide. (a) Product. Magnesium hydroxide. (b) Conditions of use. This...

  1. 21 CFR 582.1428 - Magnesium hydroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Magnesium hydroxide. 582.1428 Section 582.1428 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1428 Magnesium hydroxide. (a) Product. Magnesium hydroxide. (b) Conditions of use. This...

  2. 21 CFR 582.1428 - Magnesium hydroxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Magnesium hydroxide. 582.1428 Section 582.1428 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1428 Magnesium hydroxide. (a) Product. Magnesium hydroxide. (b) Conditions of use. This...

  3. 21 CFR 582.1428 - Magnesium hydroxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Magnesium hydroxide. 582.1428 Section 582.1428 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1428 Magnesium hydroxide. (a) Product. Magnesium hydroxide. (b) Conditions of use. This...

  4. 21 CFR 582.1428 - Magnesium hydroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium hydroxide. 582.1428 Section 582.1428 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1428 Magnesium hydroxide. (a) Product. Magnesium hydroxide. (b) Conditions of use. This...

  5. 21 CFR 582.1763 - Sodium hydroxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Sodium hydroxide. 582.1763 Section 582.1763 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1763 Sodium hydroxide. (a) Product. Sodium hydroxide. (b) Conditions of use. This...

  6. 21 CFR 184.1763 - Sodium hydroxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium hydroxide. 184.1763 Section 184.1763 Food... Specific Substances Affirmed as GRAS § 184.1763 Sodium hydroxide. (a) Sodium hydroxide (NaOH, CAS Reg. No. 1310-73-2) is also known as sodium hydrate, soda lye, caustic soda, white caustic, and lye....

  7. 21 CFR 184.1763 - Sodium hydroxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium hydroxide. 184.1763 Section 184.1763 Food... Specific Substances Affirmed as GRAS § 184.1763 Sodium hydroxide. (a) Sodium hydroxide (NaOH, CAS Reg. No. 1310-73-2) is also known as sodium hydrate, soda lye, caustic soda, white caustic, and lye....

  8. 21 CFR 582.1763 - Sodium hydroxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sodium hydroxide. 582.1763 Section 582.1763 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1763 Sodium hydroxide. (a) Product. Sodium hydroxide. (b) Conditions of use. This...

  9. 21 CFR 582.1763 - Sodium hydroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium hydroxide. 582.1763 Section 582.1763 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1763 Sodium hydroxide. (a) Product. Sodium hydroxide. (b) Conditions of use. This...

  10. 21 CFR 184.1763 - Sodium hydroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium hydroxide. 184.1763 Section 184.1763 Food... Specific Substances Affirmed as GRAS § 184.1763 Sodium hydroxide. (a) Sodium hydroxide (NaOH, CAS Reg. No. 1310-73-2) is also known as sodium hydrate, soda lye, caustic soda, white caustic, and lye....

  11. 21 CFR 582.1763 - Sodium hydroxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sodium hydroxide. 582.1763 Section 582.1763 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1763 Sodium hydroxide. (a) Product. Sodium hydroxide. (b) Conditions of use. This...

  12. 21 CFR 184.1763 - Sodium hydroxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium hydroxide. 184.1763 Section 184.1763 Food... Specific Substances Affirmed as GRAS § 184.1763 Sodium hydroxide. (a) Sodium hydroxide (NaOH, CAS Reg. No. 1310-73-2) is also known as sodium hydrate, soda lye, caustic soda, white caustic, and lye....

  13. Contribution to the knowledge of nickel hydroxide electrodes. 5. Analysis and electrochemical behavior of cadmium nickel hydroxides

    NASA Technical Reports Server (NTRS)

    Bode, H.; Dennstedt, W.

    1981-01-01

    Electrochemical experiments performed at sintered and bulk electrodes show that beta nickel hydroxide contains an electrochemically inactive proportion of cadmium hydroxide of up to 10%. The electrochemically ineffective cadmium hydroxide is homogeneously dissolved in beta nickel hydroxide.

  14. Evaluation of the effects of Er:YAG laser and desensitizing paste containing 8% arginine and calcium carbonate, and their combinations on human dentine tubules: a scanning electron microscopic analysis.

    PubMed

    Tunar, Ogul L; Gürsoy, Hare; Çakar, Gökser; Kuru, Bahar; Ipci, Sebnem Dirikan; Yılmaz, Selçuk

    2014-10-01

    The aim of this study was to evaluate the in vitro effects of Er:YAG laser and an in-office desensitizing paste alone or in combination by using scanning electron microscopic (SEM) analysis. Various treatment modalities have been proposed for dentin hypersensitivity, but to date, no single agent or form of treatment has been found effective. Forty dentine specimens obtained from freshly extracted impacted third molars were included and divided into four groups. Group I served as the control, whereas Group II, Group III, and Group IV recieved Er:YAG laser (30 Hz, 60 mJ/pulse, 10 sec), a desensitizing paste (DP) containing 8% arginine and calcium carbonate, and DP+Er:YAG laser in combination, respectively, evaluated under SEM. SEM analysis presented occlusion and narrowing of dentinal tubules in all treatment groups, but more prominent occlusion was observed in the combined treatment group. Intergroup comparisons regarding the tubule diameters and the number of the open dentinal tubules per 100 μm2 revealed statistically significant difference in favor of combined group (p<0.05). The difference between single effects of Er:YAG and DP in all parameters were found statistically nonsignificant. The present study has shown that all treatment procedures are effective in dentinal tubule occlusion. However, more prominent occlusion is observed in the combined treatment group.

  15. Efficacy of in-office bleaching techniques combined with the application of a casein phosphopeptide-amorphous calcium phosphate paste at different moments and its influence on enamel surface properties.

    PubMed

    Cunha, Ana Gabriela Gama; De Vasconcelos, Adriana Alcantara Meira; Borges, Boniek Castillo Dutra; Vitoriano, Jussier De Oliveira; Alves-Junior, Clodomiro; Machado, Claudia Tavares; Dos Santos, Alex Jose Souza

    2012-08-01

    The aim of this in vitro study was to investigate the efficacy of in-office bleaching technique combined with the application of a casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste (MI Paste-MI) at different moments and its influence on enamel surface properties. Eighty bovine dental crowns were randomly allocated into eight groups (n = 10), and bleached with either 35% hydrogen peroxide (HP) or 37% carbamide peroxide (CP). Four different protocols of application of MI were considered: without MI, MI applied before bleaching, MI applied after bleaching, and MI applied both before and after bleaching. Bleaching effectiveness was measured by the VITA EasyShade spectrophotometer utilizing the CIEL*a*b* system (ΔE, ΔL*, Δa*, and Δb*). Color readings were measured at baseline, 7, 14, and 21 days. Hardness and roughness were measured at baseline (T0) and immediately after bleaching (T14). Data were subjected to the two-way ANOVA for repeated measurements and Tukey's test at 5%. HP groups achieved the greatest color change. The application of a CPP-ACP paste did not reduce the efficacy of bleaching peroxides. Samples bleached with CP showed decreased hardness at T14. Samples bleached with HP that received the application of MI before and before/after bleaching did not present hardness decrease at T14. Samples bleached with peroxides only and received MI after bleaching showed increased roughness at T14. The use of CPP-ACP was able to prevent negative changes in roughness and hardness of bovine enamel when associated to hydrogen peroxide, and might be applied before/after the bleaching protocol. Copyright © 2012 Wiley Periodicals, Inc.

  16. Clinical and radiological evaluation of calcium sulfate as direct pulp capping material in primary teeth.

    PubMed

    Ulusoy, A T; Bayrak, S; Bodrumlu, E H

    2014-06-01

    To evaluate the clinical and radiological response of primary molars to direct pulp capping with calcium sulfate hemihydrate. Forty primary molar teeth in 40 healthy children aged 5-9 years were treated by direct pulp capping. Teeth were randomly assigned to two groups (n=20) according to material used for capping, as follows: Group 1: calcium hydroxide cement (Dycal); Group 2: calcium sulfate hemihydrate (Dentogen). All teeth were restored with a conventional glass ionomer base (Fuji IX) and amalgam. After 12 months, the overall success rate of direct pulp capping was approximately 75% (24/32 teeth, excluding exfoliations). The success rate did not differ significantly between calcium hydroxide and calcium sulfate hemihydrate treatment. Calcium sulfate hemihydrate was found to be as successful as calcium hydroxide for direct pulp capping of primary molars with Class I cavities. Further histological studies are needed to support these findings.

  17. Magnesium hydroxide as the neutralizing agent for radioactive hydrochloric acid solutions

    SciTech Connect

    Palmer, M.J.; Fife, K.W.

    1995-10-01

    The current technology at Los Alamos for removing actinides from acidic chloride waste streams is precipitation with approximately 10 M potassium hydroxide. Although successful, there are many inherent drawbacks to this precipitation technique which will be detailed in this paper. Magnesium hydroxide (K{sub sp} = 1.3 x 10{sup -11}) has limited solubility in water and as a result of the common ion effect, cannot generate a filtrate with a pH greater than 9. At a pH of 9, calcium (K{sub sp} = 5.5 x 10{sup -6}) will not coprecipitate as the hydroxide. This is an important factor since many acidic chloride feeds to hydroxide precipitation contain significant amounts of calcium. In addition, neutralization with Mg(OH){sub 2} produces a more filterable precipitate because neutralization occurs as the Mg(OH){sub 2} is dissolved by the acid rather than as a result of the much faster liquid/liquid reaction of KOH with the waste acid. This slower solid/liquid reaction allows time for crystal growth to occur and produces more easily filterable precipitates. On the other hand, neutralization of spent acid with strong KOH that yields numerous hydroxide ions in solution almost instantaneously forming a much larger volume of small crystallites that result in gelatinous, slow-filtering precipitates. Magnesium hydroxide also offers a safety advantage. Although mildly irritating, it is a weak base and safe and easy to handle. From a waste minimization perspective, Mg(OH){sub 2} offers many advantages. First, the magnesium hydroxide is added as a solid. This step eliminates the diluent water used in KOH neutralizations. Secondly, because the particle size of the precipitate is larger, more actinides are caught on the filter paper resulting in a smaller amount of actinide being transferred to the TA-50 Liquid Waste Treatment Facility. Third, the amount of solids that must be reprocessed is significantly smaller resulting in less waste generation from the downstream processes.

  18. Hydration characteristics of calcium silicate cements with alternative radiopacifiers used as root-end filling materials.

    PubMed

    Camilleri, Josette

    2010-03-01

    Mineral trioxide aggregate (MTA) is composed of calcium silicate cement and bismuth oxide added for radiopacity. The bismuth oxide in MTA has been reported to have a deleterious effect on the physical and chemical properties of the hydrated material. This study aimed to investigate the hydration mechanism of calcium silicate cement loaded with different radiopacifiers for use as a root-end filling material. Calcium silicate cement loaded with barium sulfate, gold, or silver/tin alloy was hydrated, and paste microstructure was assessed after 30 days. In addition, atomic ratio plots of Al/Ca versus Si/Ca and S/Ca and Al/Ca were drawn, and X-ray energy dispersive analysis of the hydration products was performed to assess for inclusion of heavy metals. The leachate produced from the cements after storage of the cements in water for 28 days and the leaching of the radiopacifiers in an alkaline solution was assessed by using inductively coupled plasma. The hydrated calcium silicate cement was composed of calcium silicate hydrate, calcium hydroxide, ettringite, and monosulfate. Unhydrated cement particles were few. No heavy metals were detected in the calcium silicate hydrate except for the bismuth in MTA. Calcium was leached out early in large quantities that reduced with time. The barium and bismuth were leached in increasing amounts. Copper was the most soluble in alkaline solution followed by bismuth and barium in smaller amounts. The bismuth oxide can be replaced by other radiopacifiers that do not affect the hydration mechanism of the resultant material. Copyright (c) 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  19. HISTOMICROBIOLOGIC ASPECTS OF THE ROOT CANAL SYSTEM AND PERIAPICAL LESIONS IN DOGS' TEETH AFTER ROTARY INSTRUMENTATION AND INTRACANAL DRESSING WITH Ca(OH)2 PASTES

    PubMed Central

    Soares, Janir Alves; Leonardo, Mário Roberto; da Silva, Léa Assed Bezerra; Tanomaru, Mário; Ito, Izabel Yoko

    2006-01-01

    OBJECTIVE: The purpose of this study was to evaluate the distribution of microorganisms in the root canal system (RCS) and periapical lesions of dogs' teeth after rotary instrumentation and placement of different calcium hydroxide [Ca(OHy-based intracanal dressings. MATERIALS AND METHODS: Chronic periapical lesions were experimentally induced in 80 premolar roots of four dogs. Instrumentation was undertaken using the ProFile rotary system and irrigation with 5.25% sodium hypochlorite. The following Ca(OH)2-based pastes were applied for 21 days: group 1 - Calen (n=18); group 2 - Calen+CPMC (n=20); group 3 - Ca(OH2 p.a. + anaesthetic solution (n=16) and group 4 - Ca(OH2 p.a.+ 2% chlorhexidine digluconate (n=18). Eight root canals without endodontic treatment constituted the control group. Histological sections were obtained and stained with Brown & Brenn staining technique to evaluate the presence of microorganisms in the main root canal, ramifications of the apical delta and secondary canals, apical cementoplasts, dentinal tubules, areas of cemental resorption and periapical lesions. The results were analyzed statistically by the Mann-Whitney U test (p<0.05). RESULTS: The control group showed the highest prevalence of microorganisms in all sites evaluated. Gram-positive cocci, bacilli and filaments were the most frequent morphotypes. Similar microbial distribution patterns in the RCS and areas of cementum resorption were observed in all groups (p>0.05). The percentage of RCS sites containing microorganisms in groups 1, 2, 3, 4 and control were: 67.6%, 62.5%, 78.2%, 62.0% and 87.6%, respectively. CONCLUSION: In conclusion, the histomicrobiological analysis showed that the rotary instrumentation and the different calcium hydroxide pastes employed did not effectively eliminate the infection from the RCS and periapical lesions. However, several bacteria seen in the histological sections were probably dead or were inactivated by the biomechanical preparation and calcium

  20. On the structure of amorphous calcium carbonate--a detailed study by solid-state NMR spectroscopy.

    PubMed

    Nebel, Holger; Neumann, Markus; Mayer, Christian; Epple, Matthias

    2008-09-01

    The calcium carbonate phases calcite, aragonite, vaterite, monohydrocalcite (calcium carbonate monohydrate), and ikaite (calcium carbonate hexahydrate) were studied by solid-state NMR spectroscopy ( (1)H and (13)C). Further model compounds were sodium hydrogencarbonate, potassium hydrogencarbonate, and calcium hydroxide. With the help of these data, the structure of synthetically prepared additive-free amorphous calcium carbonate (ACC) was analyzed. ACC contains molecular water (as H 2O), a small amount of mobile hydroxide, and no hydrogencarbonate. This supports the concept of ACC as a transient precursor in the formation of calcium carbonate biominerals.

  1. Carbonation acceleration of calcium hydroxide nanoparticles: induced by yeast fermentation

    NASA Astrophysics Data System (ADS)

    Lopez-Arce, Paula; Zornoza-Indart, Ainara

    2015-09-01

    Carbonation of Ca(OH)2 nanoparticles and consolidation of limestone are accelerated by high humidity and a yeast fermentation system that supplies a saturated atmosphere on CO2, H2O vapor and ethanol during 28 days. Nanoparticles were analyzed by X-ray diffraction and differential thermal analyses with thermogravimetry. Spectrophotometry, scanning electron microscopy analyses, and hydric and mechanical tests were also performed in stones specimens. Samples exposed to the yeast environment achieve 100 % relative CaCO3 yield, whereas at high humidity but without the yeast and under laboratory environment, relative yields of 95 % CaCO3 and 15 % CaCO3 are, respectively, reached, with white crusts and glazing left on the stone surfaces when the nanoparticles are applied at a concentration of 25 g/l. The largest increase in the drilling resistance and surface hardness values with slight increase in the capillarity absorption and desorption coefficients and with lesser stone color changes are produced at a concentration of 5 g/l, in the yeast system environment. This especially happens in stone specimens initially with bimodal pore size distributions, more amounts of pores with diameters between 0.1 and 1 µm, higher open porosity values and faster capillary coefficients. An inexpensive and reliable method based on water and yeast-sugar solution is presented to speed up carbonation of Ca(OH)2 nanoparticles used as a consolidating product to improve the mechanical properties of decayed limestone from archaeological and architectural heritage.

  2. Sealability of MTA and calcium hydroxide-containing sealers

    PubMed Central

    GOMES-FILHO, João Eduardo; MOREIRA, Jaqueline Viana; WATANABE, Simone; LODI, Carolina Simonetti; CINTRA, Luciano Tavares Angelo; DEZAN JUNIOR, Eloi; BERNABÉ, Pedro Felício Estrada; NERY, Mauro Juvenal; OTOBONI FILHO, José Arlindo

    2012-01-01

    Objectives The aim of this study was to evaluate the apical sealability of Fillapex®, Endo-CPM-Sealer® and Sealapex®. Material and Methods Ninety-four freshly extracted single-rooted teeth were selected and decoronated. All teeth were radiographed to confirm the existence of a single and straight root canal, which was prepared using Protaper Universal and 2.5% sodium hypochlorite. The teeth were randomly divided in groups of 10 specimens each according to the sealer, and the canals were filled using the single cone technique and one of the sealers. Four additional teeth were used as controls. The teeth were submitted to dye leakage with Rhodamine B for 24 h but using vacuum on the initial 15 min. Thereafter, they were cut longitudinally and the leakage was measured in a linear fashion from apex to crown. Data were analyzed by ANOVA and Tukey's tests at 5% significance level. Results Fillapex® and Sealapex® showed significantly less dye leakage than Endo-CPM-Sealer® (p<0.05). Conclusions It was concluded that Fillapex® and Sealapex® were able to prevent apical dye leakage differently from Endo-CPM-Sealer®. PMID:22858702

  3. [Aluminum hydroxide hydrogel to remove arsenic from water].

    PubMed

    Luján, J C

    2001-05-01

    To describe the making of and the preliminary results from an aluminum hydroxide hydrogel that, when added directly to water, can totally eliminate arsenic, regardless of the nature of the water and the oxidation state of the metalloid. The raw materials used to make the aluminum hydroxide hydrogel were: hydrated aluminum sulfate (which is used to make water safe for drinking), calcium hypochlorite in powder form, ammonium hydroxide, and distilled water (when done at the laboratory scale), and water from inverse osmosis of the same or better quality than the distilled water (when done at a pilot scale). Quality control for the finished product consisted of determining its ability to adsorb arsenic and performing bacteriological tests to demonstrate its sterility. The product was used with water samples to which arsenic had been added in the laboratory and with water samples from the province of Tucumán, Argentina, with naturally occurring arsenic. To analyze the arsenic in the water the colorimetric silver diethyldithiocarbamate method was used. Using the hydrogel greatly reduced the amount of arsenic. Treating both the natural and laboratory-produced arsenical waters yielded arsenic concentrations under the limit (0.01 parts per million) that was detectable with the analytical method used. The bacteriological tests of the finished product indicated there were no viable bacteria. Using the aluminum hydroxide hydrogel produced the desired reduction in the arsenic concentration in the water. This method for removing arsenic is inexpensive and easy to use in scattered rural populations in areas having high arsenic levels and lacking drinkable water, as well as an adequate sanitary and electric-power infrastructure.

  4. Calcium Carbonate

    MedlinePlus

    Calcium carbonate is a dietary supplement used when the amount of calcium taken in the diet is not ... for healthy bones, muscles, nervous system, and heart. Calcium carbonate also is used as an antacid to relieve ...

  5. Allergic reaction to the tetracycline component of Ledermix paste: a case report.

    PubMed

    Kaufman, A Y; Solomonov, M; Galieva, D; Abbott, P V

    2014-11-01

    Allergy to materials used during root canal treatment is well recognized in the endodontic literature. However, allergy to Ledermix paste, a compound containing triamcinolone (a corticosteroid) and demeclocycline (a tetracycline antibiotic), has not been reported apart from one very recent case in a Letter to the Editor of a journal. The aim of this report is to describe a proven allergic reaction to tetracycline following the use of Ledermix paste as a root canal medicament. A 33-year-old female patient undergoing root canal retreatment of her right mandibular second premolar tooth experienced symptoms of type 1 allergy following the placement of an intracanal medicament containing a mixture of Ledermix paste and calcium hydroxide [Ca(OH)2 ]. Signs of the type 1 allergy included urticaria, pruritus all over the body, general malaise and fever. These all subsided after removing and flushing out the Ledermix paste-Ca(OH)2 mixture and redressing the root canal with Ca(OH)2 alone. Allergic scratch tests were performed, and these confirmed that the patient was allergic to tetracycline, one of the components of Ledermix paste. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  6. Process for converting magnesium fluoride to calcium fluoride

    DOEpatents

    Kreuzmann, A.B.; Palmer, D.A.

    1984-12-21

    This invention is a process for the conversion of magnesium fluoride to calcium fluoride whereby magnesium fluoride is decomposed by heating in the presence of calcium carbonate, calcium oxide or calcium hydroxide. Magnesium fluoride is a by-product of the reduction of uranium tetrafluoride to form uranium metal and has no known commercial use, thus its production creates a significant storage problem. The advantage of this invention is that the quality of calcium fluoride produced is sufficient to be used in the industrial manufacture of anhydrous hydrogen fluoride, steel mill flux or ceramic applications.

  7. Calcium channels, external calcium concentration and cell proliferation.

    PubMed

    Borowiec, Anne-Sophie; Bidaux, Gabriel; Pigat, Natascha; Goffin, Vincent; Bernichtein, Sophie; Capiod, Thierry

    2014-09-15

    Evidence for a role for calcium channel proteins in cell proliferation is numerous suggesting that calcium influx is essential in this physiological process. Several studies in the past thirty years have demonstrated that calcium channel expression levels are determinant in cell proliferation. Voltage-gated, store-operated, second messengers and receptor-operated calcium channels have been associated to cell proliferation. However, the relationship between calcium influx and cell proliferation can be uncoupled in transformed and cancer cells, resulting in an external calcium-independent proliferation. Thus, protein expression could be more important than channel function to trigger cell proliferation suggesting that additional channel functions may be responsible to reconcile calcium channel expression and cell proliferation. When needed, external calcium concentration is obviously important for calcium channel function but it also regulates calcium sensing receptor (CaSR) activity. CaSR can up- or down-regulate cell proliferation depending on physiological conditions. CaSR sensitivity to external calcium is within the 0.5 to 5 mM range and therefore, the role of these receptors in cell proliferation must be taken into account. We therefore suggest here that cell proliferation rates could depend on the relative balance between calcium influx and CaSR activation.

  8. Paste Type Nickel Electrode Containing Compound And At Least One Other Element

    DOEpatents

    Bernard, Patrick; Bertrand, Fran.cedilla.oise; Simonneau, Olivier

    1999-11-30

    The present invention provides a paste type nickel electrode for a storage cell having an alkaline electrolyte, the electrode comprising a current collector and a paste containing a nickel-based hydroxide and an oxidized compound of cobalt syncrystallized with at least one other element, wherein said hydroxide forms a first powder and wherein said compound forms a second powder distinct from said first powder, said powders being mixed mechanically within