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Sample records for root dentine irradiated

  1. Effects of Nd: YAG laser irradiation on the root canal wall dentin of human teeth: a SEM study.

    PubMed

    Kaitsas, V; Signore, A; Fonzi, L; Benedicenti, S; Barone, M

    2001-01-01

    The purpose of this study was to observe the morphological and histological changes on the root canal walls after Nd:YAG laser application. Twenty vital, recently extracted single-rooted human teeth were used for this study. Root canals were cleaned and shaped by a conventional step-back technique--by means of k files up to a 20 k-file type at working length--and subsequently shaped by Ni-Ti root-canal rotary instrumentation up to 30/06 and irrigated with 2.5% hypochlorite solution. Ten teeth (control group) were left unlased, while the other ten teeth were irradiated with Nd:YAG laser by means of a 320 microns fibre inserted in the root canal at 1 mm from the apex with a power of 1.5 Watt and a frequency of 15 pps for five seconds in retraction with rotating movements. The control specimen showed debris and smear layer on the root canal surface obscuring the dentin tubules. The root canal walls irradiated with Nd:YAG laser showed a clear glazed surface, some open dentinal tubules and some surface craters with cracks. Such results confirm that smear layer and debris are removable with Nd:YAG laser, however clearing all root canal walls is still difficult and, if the energy level and duration of application are inadequate, a certain degree of thermal damage and morphological changes in dentin structure are observable. PMID:11938590

  2. Single session of Nd:YAG laser intracanal irradiation neutralizes endotoxin in dental root dentin

    NASA Astrophysics Data System (ADS)

    Archilla, José R. F.; Moreira, Maria S. N. A.; Miyagi, Sueli P. H.; Bombana, Antônio C.; Gutknecht, Norbert; Marques, Márcia M.

    2012-11-01

    Endotoxins released in the dental root by Gram-negative microorganisms can be neutralized by calcium hydroxide, when this medication is applied inside the root canal for at least seven days. However, several clinical situations demand faster root canal decontamination. Thus, for faster endotoxin neutralization, endodontists are seeking additional treatments. The in vitro study tested whether or not intracanal Nd:YAG laser irradiation would be able to neutralize endotoxin within the human dental root canal in a single session. Twenty-four human teeth with one root were mounted between two chambers. After conventional endodontic treatment, root canals were contaminated with Escherichia coli endotoxin. Then they were irradiated or not (controls) in contact mode with an Nd:YAG laser (1.5 W, 15 Hz, 100 mJ and pulse fluency of 124 J/cm2). The endotoxin activity was measured using the limulus lysate technique and data were statistically compared (p≤0.05). The concentration of active endotoxin measured in the negative control group was significantly lower than that of the positive control group (p=0.04). The concentrations of endotoxin in both irradiated groups were significantly lower than that of the positive control group (p=0.027) and similar to that of negative control group (p=0.20). A single session of intracanal Nd:YAG laser irradiation is able to neutralize endotoxin in the dental root tissues.

  3. Ecological Hypothesis of Dentin and Root Caries.

    PubMed

    Takahashi, Nobuhiro; Nyvad, Bente

    2016-01-01

    Recent advances regarding the caries process indicate that ecological phenomena induced by bacterial acid production tilt the de- and remineralization balance of the dental hard tissues towards demineralization through bacterial acid-induced adaptation and selection within the microbiota - from the dynamic stability stage to the aciduric stage via the acidogenic stage [Takahashi and Nyvad, 2008]. Dentin and root caries can also be partly explained by this hypothesis; however, the fact that these tissues contain a considerable amount of organic material suggests that protein degradation is involved in caries formation. In this review, we compiled relevant histological, biochemical, and microbiological information about dentin/root caries and refined the hypothesis by adding degradation of the organic matrix (the proteolytic stage) to the abovementioned stages. Bacterial acidification not only induces demineralization and exposure of the organic matrix in dentin/root surfaces but also activation of dentin-embedded and salivary matrix metalloproteinases and cathepsins. These phenomena initiate degradation of the demineralized organic matrix in dentin/root surfaces. While a bacterial involvement has never been confirmed in the initial degradation of organic material, the detection of proteolytic/amino acid-degrading bacteria and bacterial metabolites in dentin and root caries suggests a bacterial digestion and metabolism of partly degraded matrix. Moreover, bacterial metabolites might induce pulpitis as an inflammatory/immunomodulatory factor. Root and dentin surfaces are always at risk of becoming demineralized in the oral cavity, and exposed organic materials can be degraded by host-derived proteases contained in saliva and dentin itself. New approaches to the prevention and treatment of root/dentin caries are required. PMID:27458979

  4. How to bond to root canal dentin

    NASA Astrophysics Data System (ADS)

    Nica, Luminita; Todea, Carmen; Furtos, Gabriel; Baldea, Bogdan

    2014-01-01

    Bonding to root canal dentin may be difficult due to various factors: the structural characteristic of the root canal dentin, which is different from that of the coronal dentin; the presence of the organic tissue of the dental pulp inside the root canal, which has to be removed during the cleaning-shaping of the root canal system; the smear-layer resulted after mechanical instrumentation, which may interfere with the adhesion of the filling materials; the type of the irrigants used in the cleaning protocol; the type of the sealer and core material used in the obturation of the endodontic space; the type of the materials used for the restoration of the endodontically treated teeth. The influence of the cleaning protocol, of the root canal filling material, of the type of the adhesive system used in the restoration of the treated teeth and of the region of the root canal, on the adhesion of several filling and restorative materials to root canal dentin was evaluated in the push-out bond strength test on 1-mm thick slices of endodontically treated human teeth. The results showed that all these factors have a statistically significant influence on the push-out bond strength. Formation of resin tags between radicular dentin and the investigated materials was observed in some of the samples at SEM analysis.

  5. Clinical management of infected root canal dentin.

    PubMed

    Love, R M

    1996-08-01

    Several hundred different species of bacteria are present in the human intraoral environment. Bacterial penetration of root canal dentin occurs when bacteria invade the root canal system. These bacteria may constitute a reservoir from which root canal reinfection may occur during or after endodontic treatment. The learning objective of this article is to review endodontic microbiology, update readers on the role of bacteria in pulp and periapical disease, and discuss the principles of management of infected root canal dentin. Complete debridement, removal of microorganisms and affected dentin, and chemomechanical cleansing of the root canal are suggested as being the cornerstones of successful endodontic therapy, followed by intracanal medication to remove residual bacteria, when required. PMID:9242125

  6. Effects of chlorhexidine and fluoride on irradiated enamel and dentin.

    PubMed

    Soares, C J; Neiva, N A; Soares, P B F; Dechichi, P; Novais, V R; Naves, L Z; Marques, M R

    2011-05-01

    The effectiveness of mouthwash protocols in preventing gamma irradiation therapy damage to the ultimate tensile strength (UTS) of enamel and dentin is unknown. It was hypothesized that the use of chlorhexidine and fluoride mouthwash would maintain the UTS of dental structures. One hundred and twenty teeth were divided into 2 groups: irradiated (subjected to 60 Gy of gamma irradiation in daily increments of 2 Gy) and non-irradiated. They were then subdivided into 2 mouthwash protocols used 3 times per day: 0.12% chlorhexidine, 0.05% sodium fluoride, and control group (n = 10). The specimens were evaluated by microtensile testing. The results of the Tukey test (p < 0.05) indicated that the gamma irradiation therapy significantly reduced the UTS of the enamel, crown, and root dentin. Macromolecular alterations were suggested by optical retardation data in dentin. Structural alterations, in both substrates, were detected by scanning electron microscopy analysis. Mouthwash with 0.12% chlorhexidine partially prevented the damage to the mechanical properties of the irradiated crown dentin, whereas the 0.05% sodium-fluoride-irradiated enamel showed UTS similar to that of non-irradiated enamel. PMID:21335538

  7. Distribution of interglobular dentine in human tooth roots.

    PubMed

    Sato, H; Kagayama, M; Sasano, Y; Mayanagi, H

    2000-01-01

    The present study was designed to examine the distribution of interglobular dentine in human tooth roots. The material comprised 17 teeth, of which 3 were premolars extracted for orthodontic reasons from children 10-12 years of age and the other teeth (4 incisors, 3 canines and 7 molars) were extracted for periodontitis from individuals aged 32-63 years. All teeth were free of caries and cervical dentine defects. Ground sections of the teeth cut longitudinally were stained with basic fuchsin and observed by fluorescence and confocal microscopy as well as transmitted light microscopy. Basic fuchsin stained the dentinal tubules, interglobular dentine and the granular layer of Tomes. These structures appeared intense blue to faint violet with transmitted light microscopy, whereas their staining displayed intense fluorescence with fluorescence microscopy. Therefore, the interglobular dentine could be detected more sensitively with fluorescence and confocal microscopy than with transmitted light microscopy. Typical interglobular dentine was present in coronal dentine in most of the teeth. In the radicular dentin, position and size of the interglobular dentine was different among the teeth examined. Most of the teeth had the interglobular dentine in the cervical part of the roots (type A). Two premolars displayed the interglobular dentine in the coronal half of the root (type B). The types A and B contained large interglobular areas. A small amount of interglobular dentine was restricted to the apical half of the roots of two canines and one molar (type C). In contrast to types A and B which were seen at both labial or buccal and lingual sides of roots, the interglobular dentine of type C was seen only at one side, labial or lingual. Some of the tooth roots did not show any interglobular dentine (type D). Most of the incisors, canines and premolar were types A, B, and C, respectively, and the molars were mixed types A, C, and D. These results suggest that the factors

  8. Abrasion of eroded root dentine brushed with different toothpastes.

    PubMed

    De Menezes, Márcio; Turssi, Cecilia Pedroso; Hara, Anderson Takeo; Messias, Danielle Cristine Furtado; Serra, Mônica Campos

    2004-09-01

    This study evaluated the surface roughness change and wear provided by different dentifrices on root dentine previously exposed to erosive challenges. According to a randomized complete block design, 150 slabs of bovine root dentine (6 x 3 x 2 mm) were ground flat and polished. In an area of 4 x 3 mm on the dentine surface, specimens were submitted to five erosive/abrasive events, each one composed by: exposure to Sprite Diet or distilled water for 5 min, then to a remineralizing solution for 1 min, and simulation of 5,000 brushing strokes. Four dentifrices--regular (RE), baking soda (BS), whitening (WT) and tartar control (TC)--and distilled water (CO), used as control, were compared. Final texture and the wear depth were evaluated using a profilometer. ANOVA did not show significant interaction, indicating that the effect of dentifrices on both surface roughness change and wear did not depend on whether or not the dentine was eroded ( p>0.05). There was no difference between abrasion of eroded and sound dentine. The Tukey's test revealed that WT, BS and TC provided the highest increase in surface roughness differing from RE and CO. TC yielded the deepest wear of root dentine, whereas RE and CO, the shallowest. No significant difference in wear among BS, TC and WT were observed. Within the limitations of this study, the data showed that abrasion of both eroded and sound root dentine was dependent on the dentifrice used. PMID:15146320

  9. Penetration of varnishes into demineralized root dentine in vitro.

    PubMed

    Arends, J; Duschner, H; Ruben, J L

    1997-01-01

    In this paper the penetration of three different varnishes employed in caries prevention (Duraphat, Fluor Protector and Cervitec) into demineralized dentine is quantified using confocal laser scanning microscopy. The results show that the varnish penetration into lesions about 85 microns in depth if for Cervitec about 35 microns and considerably less for Duraphat and Fluor Protector. The penetration is into the dentinal tubules and is influenced by dentinal tubule direction. The drying procedure--pretreatment of the dentine--influences the penetration, though sizeably only for Cervitec applications. This paper shows that varnish penetration into the tissue and presumably 'sealing' tubules completely or partly is valuable with respect to root caries prevention and hypersensitivity. PMID:9165191

  10. Regional variation in root dentinal tubule infection by Streptococcus gordonii.

    PubMed

    Love, R M

    1996-06-01

    The purpose of this study was to investigate the pattern of bacterial invasion of dentinal tubules at different regions in human roots. Specimens were obtained from single-rooted teeth that had their root canals prepared in a standard manner. Roots were then sectioned longitudinally through the canals and the resulting specimens chemically treated to remove the smear layers. Specimens were immersed in a suspension of Streptococcus gordonii for 3 weeks and then prepared for histological analysis. Sections from the cervical, midroot, and apical areas were examined. The pattern of bacterial infection of the cervical and midroot areas was similar, characterized as a heavy infection with bacteria penetrating as deep as 200 microns. Invasion of the apical dentin was significantly different, with a mild infection and maximum penetration of 60 microns. PMID:8934987

  11. The combined use of Er,Cr:YSGG laser and fluoride to prevent root dentin demineralization

    PubMed Central

    GERALDO-MARTINS, Vinícius Rangel; LEPRI, Cesar Penazzo; FARAONI-ROMANO, Juliana Jendiroba; PALMA-DIBB, Regina Guenka

    2014-01-01

    The use of erbium lasers to prevent caries in enamel has shown positive results. However, it is not known if Er,Cr:YSGG laser can also be used to increase acid resistance of root dentine, which is another dental tissue susceptible to the action of cariogenic bacteria. Objective To analyze the effects of the Er,Cr:YSGG laser (λ=2.78 μm, 20 Hz) irradiation associated with 2% neutral sodium fluoride (NaF) to prevent root dentin demineralization. Material and Methods One hundred human root dentin samples were divided into 10 groups (G) and treated as follows: G1: no treatment; G2: NaF; G3: laser (4.64 J/cm2) with water cooling (WC=5.4 mL/min); G4: laser (4.64 J/cm2) without WC; G5: laser (8.92 J/cm2) with WC; G6: laser (8.92 J/cm2) without WC; G7: laser (4.64 J/cm2) with WC and NaF; G8: laser (4.64 J/cm2) without WC and NaF; G9: laser (8.92 J/cm2) with WC and NaF; G10: laser (8.92 J/cm2) without WC and NaF. The NaF gel was applied alone or after 4 min of irradiation. After 14 days of acid challenge, the samples were sectioned and the Knoop microhardness (KHN) test was done at different depths (30, 60, 90 and 120 μm) from the outer dentin surface. Data were analyzed by one-way ANOVA and Fisher's test (α=5%). Results The results showed that G8 and G10 presented higher KHN than the G1 for the depths of 30 and 60 μm, indicating an increase of the acid resistance of the dentin in up to 35% (p<0.05). Conclusions The use of Er,Cr:YSGG laser irradiation at 4.64 J/ cm2 and 8.92 J/cm2 without water cooling and associated with 2% NaF can increase the acid resistance of human root dentin. PMID:25466479

  12. Decontamination of deep dentin by means of erbium, chromium:yttrium-scandium-gallium-garnet laser irradiation.

    PubMed

    Franzen, René; Esteves-Oliveira, Marcella; Meister, Jörg; Wallerang, Anja; Vanweersch, Leon; Lampert, Friedrich; Gutknecht, Norbert

    2009-01-01

    The aim of this in vitro study was to evaluate the depth of effectiveness of erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation on microorganism reduction. From human roots, dentin slices of 100 microm to 1,000 microm thickness were prepared. These specimens were sterilized and then inoculated with 1 microl of Enterococcus faecalis suspension. The backs of the specimens were then irradiated with Er,Cr:YSGG radiation at a pulse energy of 3.13 mJ, delivered at an incidence angle of 5 degrees to the dentin slice surface. A control group was left without irradiation. The remaining bacteria were collected in 1 ml sterilized NaCl solution, serially diluted and seeded in Columbia-Agar plates. Despite the low pulse energy of 3.13 mJ, the Er,Cr:YSGG laser irradiation resulted in significant bacterial reduction up to a dentin thickness of 500 microm (P < 0.05). Scanning electron microscopy (SEM) micrographs of the contaminated and irradiated surfaces showed the absence of a smear layer and opened dentinal tubules. PMID:18027063

  13. In vivo model for microbial invasion of tooth root dentinal tubules

    PubMed Central

    BRITTAN, Jane L; SPRAGUE, Susan V; MACDONALD, Emma L; LOVE, Robert M; JENKINSON, Howard F; WEST, Nicola X

    2016-01-01

    ABSTRACT Objective Bacterial penetration of dentinal tubules via exposed dentine can lead to root caries and promote infections of the pulp and root canal system. The aim of this work was to develop a new experimental model for studying bacterial invasion of dentinal tubules within the human oral cavity. Material and Methods Sections of human root dentine were mounted into lower oral appliances that were worn by four human subjects for 15 d. Roots were then fixed, sectioned, stained and examined microscopically for evidence of bacterial invasion. Levels of invasion were expressed as Tubule Invasion Factor (TIF). DNA was extracted from root samples, subjected to polymerase chain reaction amplification of 16S rRNA genes, and invading bacteria were identified by comparison of sequences with GenBank database. Results All root dentine samples with patent tubules showed evidence of bacterial cell invasion (TIF value range from 5.7 to 9.0) to depths of 200 mm or more. A spectrum of Gram-positive and Gram-negative cell morphotypes were visualized, and molecular typing identified species of Granulicatella, Streptococcus, Klebsiella, Enterobacter, Acinetobacter, and Pseudomonas as dentinal tubule residents. Conclusion A novel in vivo model is described, which provides for human root dentine to be efficiently infected by oral microorganisms. A range of bacteria were able to initially invade dentinal tubules within exposed dentine. The model will be useful for testing the effectiveness of antiseptics, irrigants, and potential tubule occluding agents in preventing bacterial invasion of dentine. PMID:27119760

  14. In vivo model for microbial invasion of tooth root dentinal tubules.

    PubMed

    Brittan, Jane L; Sprague, Susan V; Macdonald, Emma L; Love, Robert M; Jenkinson, Howard F; West, Nicola X

    2016-04-01

    Objective Bacterial penetration of dentinal tubules via exposed dentine can lead to root caries and promote infections of the pulp and root canal system. The aim of this work was to develop a new experimental model for studying bacterial invasion of dentinal tubules within the human oral cavity. Material and Methods Sections of human root dentine were mounted into lower oral appliances that were worn by four human subjects for 15 d. Roots were then fixed, sectioned, stained and examined microscopically for evidence of bacterial invasion. Levels of invasion were expressed as Tubule Invasion Factor (TIF). DNA was extracted from root samples, subjected to polymerase chain reaction amplification of 16S rRNA genes, and invading bacteria were identified by comparison of sequences with GenBank database. Results All root dentine samples with patent tubules showed evidence of bacterial cell invasion (TIF value range from 5.7 to 9.0) to depths of 200 mm or more. A spectrum of Gram-positive and Gram-negative cell morphotypes were visualized, and molecular typing identified species of Granulicatella, Streptococcus, Klebsiella, Enterobacter, Acinetobacter, and Pseudomonas as dentinal tubule residents. Conclusion A novel in vivo model is described, which provides for human root dentine to be efficiently infected by oral microorganisms. A range of bacteria were able to initially invade dentinal tubules within exposed dentine. The model will be useful for testing the effectiveness of antiseptics, irrigants, and potential tubule occluding agents in preventing bacterial invasion of dentine. PMID:27119760

  15. Dentine hypersensitivity. The effects in vitro of acids and dietary substances on root-planed and burred dentine.

    PubMed

    Addy, M; Absi, E G; Adams, D

    1987-05-01

    Evidence indicates that teeth exhibiting cervical dentine hypersensitivity have open dentinal tubules at the dentine surface. The identification of factors which render dentine exposed and tubules open is important both to the prevention and management of dentine hypersensitivity. In this study, recently extracted teeth were root planed or burred to expose the root dentine. Specimens were horizontally sectioned and then using the apical portion as control, the coronal portions placed in a variety of strong and weak acids and dietary fluids. Examination under the scanning electron microscope revealed a smear layer covering completely underlying tubules on the control root planed or burred portions. Test portions exposed to strong and weak acids showed loss of the smear layer and exposure of large numbers of tubules. Formic and tannic acids produced no changes. Some dietary fluids, in particular red and white wine, citrus fruit juices, apple juice and yogurt produced similar etching effects to the acids. The low pH carbonated drink, coca-cola, and a blackcurrent cordial produced no effects. The results of this study in vitro cannot necessarily be extrapolated to the clinical situation, but suggest that certain dietary factors could play a rôle in the aetiology of dentine hypersensitivity. Dietary advice to patients may prove important in the management of this often recurrent condition. PMID:3301914

  16. Root dentine and endodontic instrumentation: cutting edge microscopic imaging.

    PubMed

    Atmeh, Amre R; Watson, Timothy F

    2016-06-01

    Cutting of the dental hard tissues is an integral part of restorative dentistry. Cutting of the root dentine is also needed in preparation prior to endodontic treatment, with significant commercial investment for the development of flexible cutting instruments based around nickel titanium (NiTi) alloys. This paper describes the evolution of endodontic cutting instruments, both in materials used, e.g. the transition from stainless steel to NiTi, and the design of the actual instruments themselves and their method of activation-by hand or motor driven. We have been examining tooth-cutting interactions microscopically for over 25 years using a variety of microscopic techniques; in particular, video-rate confocal microscopy. This has given a unique insight into how many of the procedures that we take for granted are achieved in clinical practice, by showing microscopic video images of the cutting as it occurs within the tooth. This technology has now been extended to allow imaging of the endodontic instrument and the root canal wall for the first time. We are able to image dentine distortion and crack propagation during endodontic filing of the root canal space. We are also able to visualize the often claimed, but seldom seen action of contemporary endodontic instruments. PMID:27274802

  17. Microstructure and wettability of root canal dentine and root canal filling materials after different chemical irrigation

    NASA Astrophysics Data System (ADS)

    Antonijevic, Djordje; Milovanovic, Petar; Brajkovic, Denis; Ilic, Dragan; Hahn, Michael; Amling, Michael; Rakocevic, Zlatko; Djuric, Marija; Busse, Björn

    2015-11-01

    The objective of this study was to determine the effects of various irrigation solutions on root canal dentine and gutta-percha surface properties. In addition, the effects of disinfectant chemicals on the wettability and surface morphological properties of the filling materials were evaluated. Ethylenediaminetetraacetic acid (EDTA), citric acid, and ozone were employed as irrigation solutions for dentine and gutta-percha treatment. Thereafter, the samples' microstructure, degree of mineralization, and mechanical properties were assessed by means of quantitative backscattered electron imaging (qBEI) and reference point indentation (RPI). A contact angle analyzer was used to measure adhesion on the tested materials. Here, EDTA had the most significant affect on both the mechanical properties and the adhesive behavior of dentine. Citric acid did not affect dentine wettability, whereas the indentation properties and the mineralization were reduced. Similar effects were observed when ozone was used. The dentinal tubules were significantly widened in citric acid compared to the ozone group. EDTA causes considerable micromechanical surface alteration of dentine and gutta-percha, but represents the best option in clinical cases where a high adhesiveness of the filling materials is desired.

  18. mRNA expression and protein localization of dentin matrix protein 1 during dental root formation.

    PubMed

    Toyosawa, S; Okabayashi, K; Komori, T; Ijuhin, N

    2004-01-01

    Dentin matrix protein 1 (DMP1) is an acidic phosphoprotein. DMP1 was initially detected in dentin and later in other mineralized tissues including cementum and bone, but the DMP1 expression pattern in tooth is still controversial. To determine the precise localization of DMP1 messenger RNA (mRNA) and the protein in the tooth, we performed in situ hybridization and immunohistochemical analyses using rat molars and incisors during various stages of root formation. During root dentin formation of molars, DMP1 mRNA was detected in root odontoblasts in parallel with mineralization of the dentin. However, the level of DMP1 mRNA expression in root odontoblasts decreased near the coronal part and was absent in coronal odontoblasts. DMP1 protein was localized along dentinal tubules and their branches in mineralized root dentin, and the distribution of DMP1 shifted from the end of dentinal tubules to the base of the tubules as dentin formation progressed. During the formation of the acellular cementum, DMP1 mRNA was detected in cementoblasts lining the acellular cementum where its protein was localized. During the formation of the cellular cementum, DMP1 mRNA was detected in cementocytes embedded in the cellular cementum but not in cementoblasts, and its protein was localized in the pericellular cementum of cementocytes including their processes. During dentin formation of incisors, DMP1 mRNA was detected in odontoblasts on the cementum-related dentin, where its protein was localized along dentinal tubules near the mineralization front. The localization of DMP1 mRNA and protein in dentin and cementum was related to their mineralization, suggesting that one of the functions of DMP1 may be involved in the mineralization of dentin and cementum during root formation. PMID:14751569

  19. Weakening of dentin from cracks resulting from laser irradiation

    PubMed Central

    Staninec, Michal; Meshkin, Neda; Manesh, Saman K.; Ritchie, R. O.; Fried, Daniel

    2011-01-01

    Cracking of tooth structure is a frequent mechanism of clinical failure necessitating treatment. Some laser conditions, particularly those without sufficient water cooling, may cause surface cracking of dentin. Surface cracks may serve as initiation sites for the onset of catastrophic fracture under mechanical stress, resulting in failure of the dentin. In this study, the hypothesis that laser initiated cracks result in lower bending strength of dentin was tested. Dentin beam specimens were prepared from human molar teeth, 1.1 × 1.1 × ~9 mm, and divided into groups C (control), W (wet), D (dry) of 12 beams each. In groups W, D, the middle of each beam on one surface (buccal) was irradiated with either a Er-YAG or Q-switched Er-YSGG laser and measured under a microscope, noting the dimensions in the irradiated area and immediately adjacent to irradiated area. Each beam was placed in a mechanical testing machine in a four-point bend jig and tested each with a monotonically increasing load at a displacement rate of 1 mm/min until failure. The bending strengths for groups C, W (Er-YAG laser) and D (Q-switched Er-YSGG laser) were, respectively, 141.6, 114.0, and 90.9 MPa. A one-way ANOVA determined a significant difference between groups C and D, p<0.001. Conclusion The Q-switched Er-YSGG laser without water caused cracks in the surface that significantly decreased the bending strength of dentin. PMID:19062088

  20. Effect of free electron laser (FEL) irradiation on tooth dentine

    NASA Astrophysics Data System (ADS)

    Ogino, Seiji; Awazu, Kunio; Tomimasu, Takio

    1996-12-01

    Free electron laser (FEL) gives high efficiency for the photo-induced effects when the laser is tuned to the absorption maximum of target materials. The effect on dentine was investigated using the FEL tuned to 9.4 micrometers , which is an absorption maximum of phosphoric acid in infrared region. As a result, irradiated dentine surface which was amorphous had changed to the recrystalized structure by the spectroscopic analysis of IR absorption and x-ray diffraction. Furthermore, the atomic ratio of P/Ca had reduced from 0.65 to 0.60. These results indicated that 9.4micrometers -FEL irradiation caused the selective ablation of phosphoric acid ion and the reconstruction of disordered atoms.

  1. Microorganism penetration in dentinal tubules of instrumented and retreated root canal walls. In vitro SEM study

    PubMed Central

    Al-Sulaiman, Alaa; Al-Rasheed, Fellwa; Alnajjar, Fatimah; Al-Abdulwahab, Bander; Al-Badah, Abdulhakeem

    2014-01-01

    Objectives This in vitro study aimed to investigate the ability of Candida albicans (C. albicans) and Enterococcus faecalis (E. faecalis) to penetrate dentinal tubules of instrumented and retreated root canal surface of split human teeth. Materials and Methods Sixty intact extracted human single-rooted teeth were divided into 4 groups, negative control, positive control without canal instrumentation, instrumented, and retreated. Root canals in the instrumented group were enlarged with endodontic instruments, while root canals in the retreated group were enlarged, filled, and then removed the canal filling materials. The teeth were split longitudinally after canal preparation in 3 groups except the negative control group. The teeth were inoculated with both microorganisms separately and in combination. Teeth specimens were examined by scanning electron microscopy (SEM), and the depth of penetration into the dentinal tubules was assessed using the SMILE view software (JEOL Ltd). Results Penetration of C. albicans and E. faecalis into the dentinal tubules was observed in all 3 groups, although penetration was partially restricted by dentin debris of tubules in the instrumented group and remnants of canal filling materials in the retreated group. In all 3 groups, E. faecalis penetrated deeper into the dentinal tubules by way of cell division than C. albicans which built colonies and penetrated by means of hyphae. Conclusions Microorganisms can easily penetrate dentinal tubules of root canals with different appearance based on the microorganism size and status of dentinal tubules. PMID:25383343

  2. Biological effects of a root conditioning agent for dentin surface modification in vitro

    PubMed Central

    Lee, Jue-Yeon; Seol, Yang-Jo; Park, Jang-Ryul; Park, Yoon-Jeong

    2010-01-01

    Purpose Connective tissue reattachment to periodontally damaged root surfaces is one of the most important goals of periodontal therapy. The aim of this study was to develop a root conditioning agent that can demineralize and detoxify the infected root surface. Methods Dentin slices obtained from human teeth were treated with a novel root planing agent for 2 minutes and then washed with phosphate-buffered saline. Smear layer removal and type I collagen exposure were observed by scanning electron microscopy (SEM) and type I collagen immunostaining, respectively. Cell attachment and lipopolysaccharides (LPS) removal demonstrated the efficiency of the root conditioning agent. Results SEM revealed that the smear layer was entirely removed and the dentinal tubules were opened by the experimental gel. Type I collagen was exposed on the surfaces of the dentin slices treated by the experimental gel, which were compared with dentin treated with other root planing agents. Dentin slices treated with the experimental gel showed the highest number of attached fibroblasts and flattened cell morphology. The agar diffusion assay demonstrated that the experimental gel also has effective antimicrobial activity. Escherichia coli LPS were effectively removed from well plates by the experimental gel. Conclusions These results demonstrated that this experimental gel is a useful tool for root conditioning of infected root surfaces and can also be applied for detoxification of ailing implant surface threads. PMID:21246015

  3. Comparative study of CO2 and Nd:YAG laser on dentin layer of human root canals of permanent teeth utilizing scanning electron microscopy

    NASA Astrophysics Data System (ADS)

    Brugnera, Aldo, Jr.; Lopes, Marcia C. S.; Matsumoto, Koukichi; Watanabe-Sei, Ii

    1998-04-01

    The present paper investigated the effects of two different laser beams on dentin and root canal walls. Five human intact teeth (incisors and canines), with endodontic treatment accomplished by Paiva and Antoniazzi technique, had their crowns separated from the roots using a diamond teeth. After polishing the dentin surfaces, they were irradiated with CO2 and NdYag laser and analyzed using SEM and light microscopy. The light microscopy revealed some cicunscribed carbonized areas with some cracks of varied depths in all samples but indicated that the CO2 laser, at power level of 5 watts, was more effective than NdYag laser at power level of 2 watts. The SEM showed formation of circular depressions with areas containing dentin fusion, melted dentin on small holes on the vitrified surfaces. From the data obtained, it was concluded that the methods analyzed are able to remove the remaining residues on the dentin layer and root canal walls. However, no complete fusion of the dentin layer occurred.

  4. Retrograde root filling with dentin-bonded modified resin composite.

    PubMed

    Rud, J; Rud, V; Munksgaard, E C

    1996-09-01

    A retrograde root-end cover with a special resin composite (Retroplast) combined with the dentin bonding agent Gluma (Bayer AG) has been used since 1984 by the authors. Its content of silver, added to promote radiopacity, has been found to lower the working time and storage stability of the composite and might cause discolorations. Since 1990, silver has therefore been replaced with ytterbium trifluoride, which eliminates these side effects. The purpose of this study was to compare the clinical results obtained with these two resin composites and to evaluate the healing results after several years in function. Apical fillings (351) with the modified Retroplast showed the following radiographic healing pattern 1 yr after surgery: 80% complete healing, 2% scar tissue, 12% uncertain healing, and 6% failure. No significant difference in this healing pattern was found, compared with that obtained with the silver-containing Retroplast. Cases with ytterbium trifluoride classified as scar tissue and uncertain healing at 1 yr when examined at 2 to 4 yr postoperatively showed 89% complete healing. 0% scar tissue, 1% uncertain healing, and 9% failure. This result is significantly different from that obtained 1 yr after surgery. Based on calculations, it was predicted that with time 90% will become complete healing, whereas 10% will become failure. PMID:9198430

  5. [Retrograde root filling utilizing resin and a dentin bonding agent: indication and applications].

    PubMed

    Rud, J; Rud, V; Munksgaard, E C

    1989-05-01

    With Gluma a methacrylate-based resin may be chemically bonded to dentin with considerable strength. Resin may therefore be used for retrograde root fillings. Whereas a retrograde amalgam filling demands a box-like preparation, retroplast (Gluma and resin) may be applied to a slightly concave root surface. It may therefore be employed in areas normally inaccessible with amalgam technique. Retroplast can thus be used on roots of all molars and to restore root perforations, root resorptions, cracks, grooves and defects of the root. In addition on lateral canals, on extremely thin roots and to cover perforating root canal posts, this technique can also be used. Dentin/root-cement transplantation may be performed for the purpose of reattachment. The article discusses the technique and its applications with examples showing that it may result in satisfactory healing. PMID:2696126

  6. Diode laser irradiation effects on the sealing ability of root canal sealers

    NASA Astrophysics Data System (ADS)

    Ribeiro, A. C.; Nogueira, G. E. C.; Mayer, M. P. A.; Antoniazzi, J. H.; Zezell, D. M.

    2010-06-01

    This study aimed to test the hypothesis that dentine alterations induced by 810 nm-diode laser may affect the interaction between root canal sealers and the dentin wall. Seventy-two single root human teeth were selected and root canals were enlarged with K-files. Dentine was treated with 0.5% NaOCl and 17% EDTA-T and irradiated (laser group) by diode laser (810 nm/ P = 2.5W/ I = 1989 W/cm2) or remained non-irradiated (control group). Six samples per group were analyzed by scanning electron microscopy (SEM). The remaining samples of each group were divided into three subgroups ( n = 10) and sealed with one of the tested sealers (N-Rickert/AHPlus™/Apexit®). Apical leakage was estimated by evaluating penetration of 0.5% methylene-blue dye. SEM analysis revealed that dentine at the apical third in irradiated samples was melted and fusioned whereas non-irradiated samples exhibited opened dentinal tubules. Despite the morphological changes induced by irradiation, laser did not affect the sealing ability of N-Rickert and AHPlusTM sealers. However, the length of apical leakage in roots filled with Apexit® was lower in irradiated root canals than in non-irradiated samples ( p < 0.05). Morphological changes of root canal walls promoted by diode laser irradiation may improve de sealing ability of Apexit®, a calcium hydroxide-based sealer, suggesting that improved sealing promoted by irradiation may represent an additional factor contributing to the endodontic clinical outcome.

  7. Bactericidal effect of Er:YAG laser combined with sodium hypochlorite irrigation against Enterococcus faecalis deep inside dentinal tubules in experimentally infected root canals.

    PubMed

    Cheng, X; Chen, B; Qiu, J; He, W; Lv, H; Qu, T; Yu, Q; Tian, Y

    2016-02-01

    This study evaluated the bactericidal effect of Er:YAG laser radiation combined with sodium hypochlorite (NaOCl) irrigation in the treatment of Enterococcus faecalis deep inside dentinal tubules. The Er:YAG laser was activated, respectively, at 0.3, 0.5 and 1.0 W for either 20 or 30 s; 52.5 g l(-1) NaOCl and normal saline were used for the control groups. Root canals before and after treatments were examined using scanning electron microscopy (SEM). Bacterial reductions both on the root canal walls and at 100, 200, 300, 400 and 500 μm inside the dentinal tubules were analysed using a one-way analysis of variance. SEM results showed that the Er:YAG laser combined with NaOCl disinfected the dentinal tubules from 200 to over 500 μm depth as irradiation power and time increased. This combination killed significantly more bacteria than both the negative control group at each level tested and the positive control group at 300, 400 and 500 μm inside the dentinal tubules. It reached 100% in all experimental groups, both on the root canal walls and at 100 and 200 μm inside the dentinal tubules. However, at 300, 400 and 500 μm inside the dentinal tubules, only the groups treated with 0.5 and 1.0 W for 30s exhibited no bacterial growth. Of the two groups in which no bacteria were detected at all tested depths, Er:YAG laser irradiation at 0.5 W for 30 s combined with NaOCl irrigation was preferable because of the lower emission power and shorter irradiation time, and may serve as a new option for effective root canal disinfection. PMID:26645354

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

    PubMed Central

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

    2015-01-01

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

  9. Effect of Chloroform, Eucalyptol and Orange Oil Solvents on the Microhardness of Human Root Dentin

    PubMed Central

    Khedmat, Sedigheh; Hashemi, Alaleh; Dibaji, Fatemeh; Kharrazifard, Mohammad Javad

    2015-01-01

    Objectives: This study aimed to assess the effect of chloroform, eucalyptol and orange oil solvents on the microhardness of human root dentin. Materials and Methods: Sixty-eight single-rooted single-canal extracted human premolar teeth were used. Tooth crowns were separated from the roots at the cementoenamel junction (CEJ). Roots were buccolingually sectioned into mesial and distal halves. Specimens were randomly divided into 5 groups, with 20 teeth in each solvent group and 4 teeth in each control group. Primary microhardness of specimens was measured using Vickers microhardness tester. Specimens were exposed to solvents for 15 minutes and were subjected to microhardness testing again. Data were recorded and analyzed using repeated measure ANOVA. Results: No significant difference was found in dentin microhardness before and after exposure to solvents in any of the orange oil, eucalyptol, chloroform or saline groups (P=0.727). None of the experimental groups showed any significant difference in terms of dentin microhardness reduction (P=0.99) and had no significant difference with the negative control group. Conclusion: This study showed that chloroform, eucalyptol and orange oil as gutta percha solvents did not decrease the microhardness of root dentin. Thus, none of the mentioned solvents has any superiority over the others in terms of affecting dentin properties. PMID:26005451

  10. The effect of fluoride toothpaste on root dentine demineralization progression: a pilot study.

    PubMed

    Botelho, Juliana Nunes; Del Bel Cury, Altair Antoninha; Silva, Wander Jose da; Tenuta, Livia Maria Andalo; Cury, Jaime Aparecido

    2014-01-01

    The anticaries effect of fluoride (F) toothpaste containing 1100 µg F/g in reducing enamel demineralization is well established, but its effect on dentine has not been extensively studied. Furthermore, it has been shown that toothpaste containing a high F concentration is necessary to remineralize root dentine lesions, suggesting that a 1100 µg F/g concentration might not be high enough to reduce root dentine demineralization, particularly when dentine is subjected to a high cariogenic challenge. Thus, the aim of this pilot study was to evaluate in situ the effect of F toothpaste, at a concentration of 1100 µg F/g, on dentine demineralization. In a crossover and double-blind study, conducted in two phases of 14 days, six volunteers wore a palatal appliance containing four slabs of bovine root dentine whose surface hardness (SH) was previously determined and to which a 10% sucrose solution was applied extra-orally 8×/day. Volunteers used a non-F toothpaste (negative control) or F toothpaste (1100 µg F/g, NaF/SiO2) three times a day. On the 10th and 14th days of each phase, two slabs were collected and SH was determined again. Dentine demineralization was assessed as percentage of SH loss (%SHL). The effect of toothpaste was significant, showing lower %SHL for the F toothpaste group (42.0 ± 9.7) compared to the non-F group (62.0 ± 6.4; p < 0.0001), but the effect of time was not significant (p > 0.05). This pilot study suggests that F toothpaste at 1100 µg F/g is able to decrease dentine caries even under a high cariogenic challenge of biofilm accumulation and sugar exposure. PMID:24554099

  11. Dentin Morphology of Root Canal Surface: A Quantitative Evaluation Based on a Scanning Electronic Microscopy Study

    PubMed Central

    Lo Giudice, Giuseppe; Cutroneo, Giuseppina; Centofanti, Antonio; Artemisia, Alessandro; Bramanti, Ennio; Militi, Angela; Rizzo, Giuseppina; Favaloro, Angelo; Irrera, Alessia; Lo Giudice, Roberto; Cicciù, Marco

    2015-01-01

    Dentin is a vital, hydrated composite tissue with structural components and properties that vary in the different topographic portions of the teeth. These variations have a significant implication for biomechanical teeth properties and for the adhesive systems utilized in conservative dentistry. The aim of this study is to analyse the root canal dentin going from coronal to apical zone to find the ratio between the intertubular dentin area and the surface occupied by dentin tubules varies. Observations were conducted on 30 healthy premolar teeth extracted for orthodontic reasons in patients aged between 10 and 14. A SEM analysis of the data obtained in different canal portions showed that, in the coronal zone, dentinal tubules had a greater diameter (4.32 μm) than the middle zone (3.74 μm) and the apical zone (1.73 μm). The average number of dentinal tubules (in an area of 1 mm2) was similar in coronal zone (46,798 ± 10,644) and apical zone (45,192 ± 10,888), while in the middle zone they were lower in number (30,940 ± 7,651). However, intertubular dentin area was bigger going from apical to coronal portion. The differences between the analysed areas must be considered for the choice of the adhesive system. PMID:26413504

  12. The surface of root canal irradiated by Nd:YAG laser with TiO2

    NASA Astrophysics Data System (ADS)

    Ebihara, Arata; Anjo, Tomoo; Takeda, Atsushi; Suda, Hideaki

    2004-05-01

    The aim of this study was to determine the appropriateness of Nd:YAG laser irradiation for root canal preparation. Tooth crowns were removed from single-rooted human teeth and a quartz optical fiber (diameter 400 μm) was inserted into the root canal orifice towards the apical foramen. The length of the fiber within the root canal was measured, and the irradiating length determined. Root canals were then filled with 3% TiO2 emulsion solution (a photosensitizer) and irradiated using a pulsed Nd:YAG laser at 600 mJ/pulse (pulse frequency; 5 or 10 pps). During laser irradiation, the fiber was moved coronally from the apical region towards the canal orifice at a rate of 1 mm/s. Contact microradiographs (CMR) were taken before and after laser irradiation. Each root was then halved longitudinally, and the root canal surface observed by scanning electron microscopy (SEM). The CMR images of the tooth revealed that the root canal was slightly enlarged as a result of treatment. Carbonization of the root canal dentin was not seen, but a smear layer and melted dentin were observed by SEM. Nd:YAG laser irradiation using TiO2 emulsion solution appears to be a useful tool for root canal preparation.

  13. Evaluation of phase, microstructure and composition of human dentine after Er,Cr:YSGG laser irradiation.

    PubMed

    Lin, Shi; Pan, Danmei; Lin, Qi; Yin, Shungao; Chen, Dagui; Liu, Qinghua; Yu, Lili; Lin, Zhang

    2011-03-01

    This study aims to evaluate the composition, micro-structure and inorganic phase alternations of human dentine irradiated by Er,Cr:YSGG laser with water cooling spray system. X-ray diffraction (XRD) analysis indicated that the main inorganic phase of dentine before and after laser irradiation were all Hydroxyapatite (HA) structure, approximately 30 nm in size. No significant changes occurred in the average particle size after irradiation in four energy densities (6.18 J/cm2, 8.04 J/cm2, 9.89 J/cm2, 11.1 J/cm2). Atomic force microscope (AFM) phase image and the energy-dispersive spectroscope (EDS) analysis, however, demonstrated that the thermal effects of Er,Cr:YSGG laser with water-cooling spray system on the dentin surface was intense enough to induce notable decrease of the organic matter. Both scanning electron microscopy (SEM) and AFM analysis showed that the irradiated dentine presented rough surface morphology. The surface is clean and dentinal tubules are completely open. The ablation rate of both peri- and intertubular dentine increased at higher energy densities but no significant changes of gross appearance took place. Chemical analysis reveals that laser photothermal effect would decrease significantly the organic content of superficial dentinal layer. We conclude that the Er,Cr:YSGG laser, as a new type clinic laser, would not significantly influence the inorganic phase structure of the surface dentine layer, however, thermal ablation was occurred in organic component. Moreover, the rough ablated surface as well as the opened dentinal tubules induced by irradiation, might be advantageous to the infiltration of the adhesive materials, thus the adhesion of dental restoration could be enhanced. Further studies should focus on the correlation between bond strength and Er,Cr:YSGG lased dentine. PMID:21449402

  14. Decalcifying capability of irrigating solutions on root canal dentin mineral content

    PubMed Central

    Poggio, Claudio; Dagna, Alberto; Vinci, Andrea; Beltrami, Riccardo; Cucca, Lucia; Giardino, Luciano

    2015-01-01

    Background: Chelating agents are believed to aid root canal irrigation and to be able to remove the inorganic smear layer. Aims: The purpose of the present study was to evaluate and to compare the decalcifying capability of different irrigating solutions (Tubuliclean, Largal Ultra, ethylenediaminetetraacetic acid 17%, Tetraclean, Tetraclean NA). Materials and Methods: Sixty maxillary central incisors were used. Root canals were instrumented and irrigated. From each root, four comparable slices of cervical dentin were obtained. At three successive 5-min interval immersion times, the concentration of calcium extracted from root canal dentin was assessed with an inductively coupled plasma-atomic emission spectrometer. Statistical Analysis Used: Data were analyzed by means of Kruskal Wallis and Mann–Whitney tests. Significance was predetermined at P < 0.05. Results and Conclusions: For all irrigating solutions, the maximum amount of Ca2+ extracted from root canal dentin samples was reached after 10 min contact time except for citric acid-based agents (Tetraclean and Tetraclean NA) which induced a higher and still increasing calcium release even after 10 min contact time. In order to obtain an efficient decalcifying action on dentin and to facilitate the biomechanical procedures, citric acid-based irrigants can be applied. PMID:26097355

  15. Effect of Peracetic Acid as A Final Rinse on Push Out Bond Strength of Root Canal Sealers to Root Dentin

    PubMed Central

    Gaddala, Naresh; Veeramachineni, Chandrasekhar

    2015-01-01

    Background Smear layer which was formed during the instrumentation of root canals hinders the penetration of root canal sealers to root dentin and affect the bond strength of root canal sealers to root dentin. Final irrigant such as demineralizing agents are used to remove the inorganic portion of the smear layer. In the present study, peracetic acid used as a final rinse, to effect the bond strength of root canal sealers to root dentin. Aim The purpose of the present study was to evaluate the efficacy of peracetic acid as a final irrigant on bond strength of root canal sealers to root dentin. Materials and Methods Sixty six freshly extracted human single rooted mandibular premolars were used for this study. After decoronation the samples were instrumented with Protaper upto F3 and irrigated with 5.25% NaOcl. The teeth were then divided into three groups based on final irrigant used: Group-1(control group) Canals were irrigated with distilled water. Group-2: Canals were irrigated with peracetic acid. Group-3: Canals were irrigated with smear clear. Each group was further divided into three subgroups (n=30) based on the sealer used to obturate the canals. Subgroup-1: kerr, Subgroup-2: Apexit plus, Subgroup-3: AH PLUS. Each sealer was mixed and coated to master cone and placed in the canal. The bonding between sealer and dentin surface was evaluated using push out bond strength by universal testing machine. The mean bond strength values of each group were statistically evaluated using Two-way ANOVA followed by Tukey post-hoc test. Results Significant difference was found among the bond strength of the sealers. But, there is no statistically significant difference between the groups irrigated with peracetic acid and smear clear compared to control group. AH Plus showed highest bond strength irrespective of the final irrigant used. Conclusion Peracetic acid when employed as final irrigant improved the bond strength of root canal sealers compared to control group but

  16. Biofilm Formation within the Interface of Bovine Root Dentin Treated with Conjugated Chitosan and Sealer Containing Chitosan Nanoparticles

    PubMed Central

    DaSilva, Luis; Finer, Yoav; Friedman, Shimon; Basrani, Bettina; Kishen, Anil

    2013-01-01

    Objective To assess biofilm formation within sealer-dentin interfaces of root segments filled with gutta-percha and sealer incorporated with chitosan (CS) nanoparticles, without and with canal surface treatment with different formulations of CS. Methods Standardized canals of 4 mm bovine root segments (n=35) were filled with gutta-percha and Pulp Canal Sealer incorporated with CS nanoparticles without surface treatment (group CS), or after surface treatment with phosphorylated CS (group PHCS), CS-conjugated Rose Bengal and photodynamic irradiation (group CSRB) and a combination of both PHCS and CSRB (group RBPH). The control group was filled with gutta-percha and unmodified sealer. After 7 d of setting, specimens were aged in buffered solution at 37° C for 1 or 4 wks. Monospecies biofilms of Enterococcus faecalis were grown on specimens for 7 d in a chemostat-based biofilm fermentor. Biofilm formation within the sealer-dentin interface was assessed with confocal laser scanning microscopy. Results In the 4-wk aged specimens only, the mean biofilm areas were significantly smaller than in the control for CS (p=0.008), PHCS (p=0.012) and RBPH (p=0.034). Percentage of biofilm-covered interface also was significantly lower than in the control for CS (p=0.024) and PHCS (p=0.003). CS, PHCS and RBPH did not differ significantly. Conclusions Incorporating CS nanoparticles into the zinc-oxide eugenol sealer inhibited biofilm formation within the sealer-dentin interface. This effect was maintained when canals were treated with phosphorylated CS, and it was moderated by canal treatment with chitosan-conjugated Rose Bengal and irradiation. PMID:23321239

  17. Effect of acid fruit juices combined with electric or sonic toothbrushing on root dentin permeability--an in vitro study.

    PubMed

    Batitucci, Roberta Grasselli; Zandim, Daniela Leal; Rocha, Fernanda Regina Godoy; Pinheiro, Michele Carolina; Fontanari, Lucas Amaral; Sampaio, José Eduardo Cezar

    2012-01-01

    The purpose of this in vitro study was to quantify the alterations on human root dentin permeability after exposure to different acid fruit juices and to evaluate the effect of toothbrushing with electric or sonic toothbrush after acid exposure. The root dentin of 50 extracted third molars was exposed with a high speed bur. Crowns were sectioned above the cementoenamel junction and root fragments were used to prepare dentin specimens. Specimens were randomly assigned to 5 groups according to the fruit juice (kiwifruit, starfruit, green apple, pineapple and acerolla). Each specimen was connected to a hydraulic pressure apparatus to measure root dentin permeability using fluid filtration method after the following sequential steps: I) conditioning with 37% phosphoric acid for 30 s, II) root scaling, III) exposure to acid fruit juices for 5 min and IV) electric or sonic toothbrushing without dentifrice for 3 min. Data were analyzed statistically by the Wilcoxon and Mann-Whitney tests at 5% significance level. All fruit juices promoted a significant increase of dentin permeability while toothbrushing decreased it significantly (p<0.05). It may be concluded that all acid fruit juices increased root dentin permeability, while toothbrushing without dentifrice after acid exposure decreased the permeability. The toothbrush mechanism (electric or sonic) had no influence on the decrease of root dentin permeability. PMID:23338258

  18. Periapical Microsurgery: The effect of root dentinal defects on short and long term outcome

    PubMed Central

    Tawil, Peter Z.; Saraiya, Veeral M.; Galicia, Johnah C.; Duggan, Derek J.

    2015-01-01

    Introduction The purpose of this prospective clinical study is to evaluate the clinical outcome of endodontic microsurgery on roots exhibiting the presence or absence of dentinal defects at one year and three-year follow up period. Methods 155 teeth were treated with periapical microsurgery using a modern microsurgical protocol in a private practice setting. The root apices were resected and inspected for dentinal defects with a Surgical Operating Microscope and a 0.8mm head diameter LED microscope diagnostic probe light. After inspection, retrograde preparations were performed using ultrasonic tips and retrograde fillings were placed. Follow up visits occurred at one year and three years post-operatively. The primary outcome measure employed was the change in the radiographic apical bone density and the secondary outcome measure used was the absence of clinical symptoms. Results Out of the 155 treated teeth, a total of 134 teeth were assessed at the one-year follow-up and 127 teeth at the three-year evaluation. The “Intact” group had 94.8% healed at one year and 97.3% healed at three years. The “Dentinal Defect” group had 29.8% healed at one year and 31.5% healed at three years. The baseline root condition of either “Dentinal Defect” or “Intact” showed a statistical difference in the healing outcome at both one year and at three years. Conclusions This prospective periapical microsurgery study showed a significant superior clinical outcome for intact roots when compared to roots with dentinal defects at both 1 year and at 3 years post-operatively. PMID:25282374

  19. The initial attachment of cemental fibrils to the root dentin surface in acellular and cellular cementogenesis in rat molars.

    PubMed

    Yamamoto, T; Domon, T; Takahashi, S; Islam, M N; Suzuki, R

    2001-03-01

    To elucidate the initial attachment mechanism of cemental fibrils to the root dentin surface in acellular and cellular cementogenesis, developing rat molars were observed by light microscopy and scanning electron microscopy combined with NaOH maceration. The NaOH maceration was used to observe details of the positional association of cemental and dentinal fibrils during cementogenesis. An initial hematoxylin stained, cementum layer began to form on the root dentin surface with the first dentin mineralization in both acellular and cellular cementogenesis. The initial attachment of cemental fibrils to the dentin surface also began at this point. At the initial attachment the intermingling of cemental and dentinal fibrils occurred only in places. With advanced cementogenesis the initial cementum layer became the fibril-poor cemento-dentinal junction. This suggests that cemental fibrils attach on the initial cementum layer, and not directly on dentinal fibrils, so that the layer results in the fibril-poor cemento-dentinal junction. The present study suggests that an intervening adhesive is necessary for the cemento-dentinal attachment at any stage of cementogenesis in rat molars. PMID:11325058

  20. Effect of gutta-percha solvents on fiberglass post bond strength to root canal dentin.

    PubMed

    Guedes, Orlando A; Chaves, Gustavo S; Alencar, Ana H G; Borges, Alvaro H; Estrela, Cyntia R A; Soares, Carlos J; Estrela, Carlos

    2014-06-01

    The purpose of this study was to investigate the influence of gutta-percha solvents on the bond strength of fiberglass post to root canal dentin. Forty bovine incisors were decoronated, prepared, filled, and randomly distributed into four groups (n = 10) according to the gutta-percha solvent used: control, xylene, eucalyptol and orange oil. After root canal treatment, the posts were cemented into the prepared root canals using a resin-based cement. A micro push-out test was executed, and the patterns of failure were assessed with microscopy. The data were analyzed using two-way ANOVA followed by Tukey's test. The control group exhibited greater bond strength compared to the eucalyptol group in the cervical and middle thirds of the root (P < 0.05); however, it did not differ significantly from the xylene and orange oil groups (P > 0.05). No difference was observed in the values of the xylene, orange oil, and eucalyptol groups (P > 0.05). The cervical third had higher values than the apical third for all tested solvents (P < 0.05). Adhesive failure between resin cement and dentin was the most frequent type of failure. The use of xylene and orange oil as gutta-percha solvents did not influence the bond strength of fiberglass posts to root canal dentin. PMID:24930746

  1. Effect of instrumentation with different irrigating solutions and with or without Er:YAG laser irradiation on radicular dentine permeability

    NASA Astrophysics Data System (ADS)

    Pecora, Jesus D.; Ribeiro, Rodrigo G.; Marchesan, Melissa A.; Brugnera, Aldo, Jr.

    2004-05-01

    This study evaluated radicular dentine permeability of root canal walls when using different irrigating solutions associated or not with Er:YAG laser. Fifty human maxillary incisors, obtained from laboratory stock, were randomly divided into ten groups of five teeth each. External surfaces of the teeth were impermeabilized with cyanoacrylate (Super Bonder). After chamber access, the root canals were instrumented with the step-back technique. Ten ml of irrigating solution was used in each root canal. Group I: irrigated with distilled and deionized water; Group II: irrigated as Group I and irradiated with laser; Group III: irrigated with 0.1% laurel diethyleneglycol ether sodium sulfate; Group IV: irrigated as Group III and irradiated with laser; Group V: irrigated with 1% sodium hypochlorite; Group VI: irrigated as Group V and irradiated with laser; Group VII: irrigated with 15% EDTA; Group VIII: irrigated as Group VII and irradiated with laser; Group IX: irrigated with 10% citric acid; Group X: irrigated as Group IX and irradiated with laser. Laser (KaVo Key Laser II) was applied with the following parameters: 15 Hz, 300 pulses, 42 J total energy, and 140mJ input and 51mJ ouput. The fiber optic tip was introduced until the apex and the laser was activated. The tip was withdrawn gently with helicoidally movement from the apex until the cervical portion. After preparation of the root canals, the root were immersed in 10% copper sulfate for 30 minute and then immersed in 1% rubeanic acid alcohol solution for the same period. The roots were sectioned transversally into 150μm slices, sanded, washed, dehydrated, cleared and mounted on glass slides for microscopic examination. The quantification of the penetration of copper ions was done by morphometric analysis. Results showed that distilled and deionized water + laser and 1% sodium hypochlorite presented the highest dentine permeability (p>0.05) and was statistically different from the other groups (p<0.05). The use of

  2. Effect of Cyclic Loading on Bond Strength of Fiber Posts to Root Canal Dentin

    PubMed Central

    Khamverdi, Zahra; Damavandi, Leila Yazdani; Kasraei, Shahin

    2014-01-01

    Objective: The aim of this study was to evaluate the effect of cyclic loading on the bond strength of quartz fiber posts to root canal dentin after different surface treatments of different regions of root canal dentin. Materials and Methods: Forty-eight single-rooted human teeth were selected. Post spaces were prepared and then the teeth were divided into four groups: G1: no treatment (control); G2: irrigation with a chemical solvent; G3: etching with 37% phosphoric acid; G4: treatment with ultrasonic file. The fiber posts were cemented using dual-cured resin cement. Half of the specimens were load-cycled (10000 cycles, 3 cycles/s) and the others did not undergo any load cycling. From each root, two slides measuring 1 mm in thickness were obtained from the apical and cervical regions. The push-out bond strength test was performed for each slice. Data were analyzed by using 3-way ANOVA and Tukey HSD tests. The fracture modes were evaluated under a stereomicroscope at ×20. Results: The effect of load cycling and surface treatment as the main factors and the interaction of main factors were not significant (P=0.734, P=0.180, and P=0.539, respectively). The most frequent failure mode under the stereomicroscope was adhesive. Conclusion: It appears that load cycling and surface treatment methods had no effect on the bond strength of fiber posts to root canal dentin, but it depended on the region of the root canal dentin. PMID:24910680

  3. Crystallographic Texture and Elemental Composition Mapped in Bovine Root Dentin at the 200 nm Level

    PubMed Central

    Deymier-Black, A. C.; Veis, A.; Cai, Z.; Stock, S. R.

    2015-01-01

    Summary The relationship between the mineralization of peritubular dentin (PTD) and intertubular dentin (ITD) is not well understood. Tubules are quite small, diameter ~2 μm, and this makes the near-tubule region of dentin difficult to study. Here, advanced characterization techniques are applied in a novel way to examine what organic or nanostructural signatures may indicate the end of ITD or the beginning of PTD mineralization. X-ray fluorescence intensity (Ca, P, and Zn) and X-ray diffraction patterns from carbonated apatite (cAp) were mapped around dentintubules at resolutions ten times smaller than the feature size (200 nm pixels), representing a 36% increase in resolution over earlier work. In the near tubule volumes of near-pulp, root dentin, Zn intensity was higher than in ITD remote from the tubules. This increase in Zn2+, as determined by X-ray absorption near edge structure analysis, may indicate the presence of metalloenzymes or transcription factors important to ITD or PTD mineralization. The profiles of the cAp 00.2 X-ray diffraction rings were fitted with a pseudo-Voigt function, and the spatial and azimuthal distribution of these rings’ integrated intensities indicated that the cAp platelets were arranged with their c-axes aligned tangential to the edge of the tubule lumen. This texture was continuous throughout the dentin indicating a lack of structural difference between in the Zn rich near-tubular region and the remote ITD. PMID:23630059

  4. Adaptation and penetration of resin-based root canal sealers in root canals irradiated with high-intensity lasers

    NASA Astrophysics Data System (ADS)

    Moura-Netto, Cacio; Mello-Moura, Anna Carolina Volpi; Palo, Renato Miotto; Prokopowitsch, Igor; Pameijer, Cornelis H.; Marques, Marcia Martins

    2015-03-01

    This research analyzed the quality of resin-based sealer adaptation after intracanal laser irradiation. Extracted teeth (n=168) were root canal treated and divided into four groups, according to dentin surface treatment: no laser; Nd:YAG laser (1.5 W, 100 mJ, 15 Hz) diode laser (2.5 W in CW), and Er:YAG laser (1 W, 100 mJ, 10 Hz). The teeth were divided into four subgroups according to the sealer used: AH Plus, EndoREZ, Epiphany, and EpiphanySE. For testing the sealing after root canal obturation, the penetration of silver nitrate solution was measured, whereas to evaluate the adaptation and penetration of the sealer into the dentin, environmental scanning electron microscopy (ESEM) was used. The ESEM images were analyzed using a four-grade criteria score by three evaluators. The inter-examiner agreement was confirmed by Kappa test and the scores statistically compared by the Kruskal-Wallis' test (p<0.05). Both adaptation and sealer penetration in root canals were not affected by the laser irradiation. Nd:YAG and diode laser decreased the tracer penetration for AH Plus, whereas EndoREZ and EpiphanySE performances were affected by Nd:YAG irradiation (p<0.05). It can be concluded that intracanal laser irradiation can be used as an adjunct in endodontic treatment; however, the use of hydrophilic resin sealers should be avoided when root canals were irradiated with Nd:YAG laser.

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

    PubMed Central

    2016-01-01

    Due to gingival recession both enamel and root dentine are at risk of developing caries. Both tissues are exposed to a similar environment, however there is not a validated model to evaluate the effect of fluoride on these dental substrates simultaneously. Hence, this study aimed to validate a caries model to evaluate the effect of fluoride to prevent demineralization on enamel and root-dentine. Streptococcus mutans UA159 biofilms were formed on saliva-coated bovine enamel and root dentine slabs (n = 12 per group) mounted in the same well of culture plates. The biofilms were exposed 8×/day to 10% sucrose and treated 2×/day with fluoridated solutions containing 0, 150, 450, or 1,350 ppm F; thus, simulating the use of low to high fluoride concentration toothpastes. The pH values of the culture medium was monitored 2×/day as a biofilm acidogenicity indicator. After 96 h, biofilms were collected for fluoride concentration analysis. The percentage of surface hardness loss (%SHL) was calculated for slabs. The fluoride uptake by the enamel and dentine was also determined. The model showed a dose-response because the biofilm and fluoride uptake increased and %SHL decreased at increasing fluoride concentrations (p < 0.05). Fluoride in the biofilm formed on dentine and fluoride uptake by dentine were higher than those for enamel. With the same fluoride concentration treatment, the percentage of reduction of demineralization was lower for dentine than for enamel. In conclusion, the model was validated in terms of a dose-response effect of fluoride on enamel and root dentine. Furthermore, the findings support the clinical data, suggesting that higher fluoride concentrations are necessary to control caries of root dentine than of enamel. PMID:26731743

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

    PubMed

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

    2016-01-01

    Due to gingival recession both enamel and root dentine are at risk of developing caries. Both tissues are exposed to a similar environment, however there is not a validated model to evaluate the effect of fluoride on these dental substrates simultaneously. Hence, this study aimed to validate a caries model to evaluate the effect of fluoride to prevent demineralization on enamel and root-dentine. Streptococcus mutans UA159 biofilms were formed on saliva-coated bovine enamel and root dentine slabs (n = 12 per group) mounted in the same well of culture plates. The biofilms were exposed 8×/day to 10% sucrose and treated 2×/day with fluoridated solutions containing 0, 150, 450, or 1,350 ppm F; thus, simulating the use of low to high fluoride concentration toothpastes. The pH values of the culture medium was monitored 2×/day as a biofilm acidogenicity indicator. After 96 h, biofilms were collected for fluoride concentration analysis. The percentage of surface hardness loss (%SHL) was calculated for slabs. The fluoride uptake by the enamel and dentine was also determined. The model showed a dose-response because the biofilm and fluoride uptake increased and %SHL decreased at increasing fluoride concentrations (p < 0.05). Fluoride in the biofilm formed on dentine and fluoride uptake by dentine were higher than those for enamel. With the same fluoride concentration treatment, the percentage of reduction of demineralization was lower for dentine than for enamel. In conclusion, the model was validated in terms of a dose-response effect of fluoride on enamel and root dentine. Furthermore, the findings support the clinical data, suggesting that higher fluoride concentrations are necessary to control caries of root dentine than of enamel. PMID:26731743

  7. Er:YAG laser irradiation on dentin: FT-Raman and SEM studies

    NASA Astrophysics Data System (ADS)

    Soares, Luís Eduardo Silva; Bitar, Renata Andrade; Brugnera, Aldo; Zanin, Fatima A. A.; Resende, Erick B. P. S.; Jara, Walter A. A.; Martin, Airton A.

    2007-02-01

    This study evaluated the molecular and morphological changes on dentin elements after the Er:YAG laser irradiation. Six human third molars were selected and the occlusal one-third of the crown was removed. The dentin surface was schematically divided into areas corresponding to four surface treatments groups: Control (Group C): 37% phosphoric acid etching; Group I: Er:YAG laser 80mJ; Group II: Er:YAG laser 120mJ; Group III: Er:YAG laser 180mJ. The characterization was performed by Scanning Electron Microscopy (SEM) and Fourier-Transformed Raman Spectroscopy (FT-Raman) before and after the treatments. A reduction of the relative intensity for the spectra was observed in the Group II and III samples. The SEM photomicrographies revealed open dentin tubules in the control group specimens. The groups I, II and III presented partially open dentin tubules. SEM images showed that the laser-irradiated dentin surface was not favorable to the diffusion of monomers. The chemical information obtained by Raman spectroscopy showed that higher laser energies (180 mJ) affected more the phosphate, carbonate and the organic components of dentin.

  8. Morphological analysis of dentin tissue after Er, Cr: YSGG laser irradiation

    NASA Astrophysics Data System (ADS)

    Yu, Lili; Lin, Qi; Zhang, Xianzeng; Zhan, Zhenlin; Lin, Shi; Xie, Shusen

    2009-08-01

    The object of this study is to evaluate the morphological changes of dentin tissue after Er, Cr: YSGG laser Irradiation. The wavelength is 2.78 μm with pulse repetition rate of 20 Hz and pulse duration of 140 μs. The samples extracted from sound intact adult human premolars were cut into 1 mm thick dentin slices, and then polished by abrasive papers. After preparation, specimens were randomly divided into two groups: one group treated with conventional drills (a diamond drill and a fissure bur), and the other group treated with lasers at four different power settings (2W to 3.5W). The morphological alterations produced by the different treatments were observed and compared by scanning electron microscope (SEM). It showed that the dentin surfaces had distinct and characteristic morphological alteration with different power settings. Compared with the samples treated with conventional drills, the irradiated samples revealed an absent smear layer with open dentinal tubules. The ablation of intertubular dentin was more evident than that of peritubular dentin.

  9. Centering ability and dentin removal of rotary systems in curved root canals

    PubMed Central

    Moradi, Saeed; Talati, Ali; Monajem Zadeh, Ali

    2009-01-01

    INTRODUCTION: The aim of this study was to compare centering ability and dentin removal of three rotary systems in curved root canals of extracted teeth. MATERIALS AND METHODS: Sixty root canals of mandibular first molars with curvatures ranging between 25-35o were divided into three groups of 20 teeth each. Based on pre-instrumentation radiographs that assessed the angle and the radius of canal curvatures, teeth with curvatures were equally spread between the three groups. The root canals were sectioned horizontally at two levels before preparation and then remounted onto the muffle. All root canals were prepared using a low-torque control motor with Mtwo or Medin or Race instruments. Cross sectional images were obtained before and after instrumentation. Cross-sectional area and centering ability were evaluated. The data were analyzed using the one-way ANOVA and Tukey tests. RESULTS: Neither instrument fracture nor permanent deformation occurred during preparations. The best centering ability was obtained by Mtwo instruments compare to Race and Medin instruments. In the coronal and middle sections, Mtwo removed less dentin than Race and Medin; while the difference in the apical section was not significant. CONCLUSION: Under the conditions of this study, the debridement of root canals was more conservative with Mtwo. The canals prepared with these instruments were better centered in all three regions of the root. PMID:24003328

  10. The burnishing effect of sodium (saline) chloride on root dentin: an in vitro study.

    PubMed

    Babay, N

    2001-09-01

    The purpose of this in vitro study was to evaluate the burnishing effect of saline application on dentin specimens (NaCl 0.9%). Seventy-two dentin specimens (60 experimental and 12 controls) were equally divided into two groups. In Group A; sub-groups I, II, III, IV and V were respectively soaked with saline for 5 s, 10 s, 30 s, 1 min and 2 min. Group VI was soaked in citric acid for 3 min and served as control. Identical treatment was done in-group B with one exception, burnishing instead of soaking was applied to the root surface. Five, ten and thirty seconds burnishing with saline and all the different timings with the soaking technique did not remove the smear layer. This was in contrast to burnishing dentin surface for 1 and 2 min, which effectively removed the smear layer. It cannot be excluded that the smear layer removal is time dependent when the dentin is burnished with saline. PMID:11808370

  11. Marginal adaptation of newer root canal sealers to dentin: A SEM study

    PubMed Central

    Polineni, Swapnika; Bolla, Nagesh; Mandava, Pragna; Vemuri, Sayesh; Mallela, Madhusudana; Gandham, Vijaya Madhuri

    2016-01-01

    Aim: This in vitro study evaluated and compared the marginal adaptation of three newer root canal sealers to root dentin. Materials and Methods: Thirty freshly extracted human single-rooted teeth with completely formed apices were taken. Teeth were decoronated, and root canals were instrumented. The specimens were randomly divided into three groups (n = 10) based upon the sealer used. Group 1 - teeth were obturated with epoxy resin sealer (MM-Seal). Group 2 - teeth were obturated with mineral trioxide aggregate (MTA) based sealer (MTA Fillapex), Group 3 - teeth were obturated with bioceramic sealer (EndoSequence BC sealer). Later samples were vertically sectioned using hard tissue microtome and marginal adaptation of sealers to root dentin was evaluated under coronal and apical halves using scanning electron microscopy (SEM) and marginal gap values were recorded. Results: The data were statistically analyzed by two-way ANOVA and Tukey's multiple post hoc test. The highest marginal gap was seen in Group 2 (apical-16680.00 nm, coronal-10796 nm) and the lowest marginal gap was observed in Group 1 (apical-599.42 nm, coronal-522.72 nm). Coronal halves showed superior adaptation compared to apical halves in all the groups under SEM. Conclusion: Within the limitations of this study epoxy resin-based MM-Seal showed good marginal adaptation than other materials tested. PMID:27563187

  12. Effect of QMix, peracetic acid and ethylenediaminetetraacetic acid on calcium loss and microhardness of root dentine

    PubMed Central

    Taneja, Sonali; Kumari, Manju; Anand, Surbhi

    2014-01-01

    Objectives: The objective of this in vitro study was to assess the effect of different chelating agents on the calcium loss and its subsequent effect on the microhardness of the root dentin. Materials and Methods: Ten single rooted lower premolars were selected. The teeth were decoronated and thick transverse sections of 2 mm were obtained from the coronal third of the root. Each section was then divided into four quarters, each part constituting a sample specimen from the same tooth for each group. The treatment groups were: Group 1 (Control): 5% Sodium hypochlorite (NaOCl) for 5 min + distilled water for 5 min; Group 2: 5% NaOCl for 5 min + 17% ethylenediaminetetraacetic acid (EDTA) for 5 min; Group 3: 5% NaOCl for 5 min + 2.25% Peracetic acid (PAA) for 5 min and Group 4: 5% NaOCl for 5 min + QMix for 5 min respectively. The calcium loss of the samples was evaluated using the Atomic Absorption Spectrophotometer followed by determination of their microhardness using Vickers Hardness Tester. Data was analyzed using one-way ANOVA, Post hoc Tukey test and Pearson correlation. Results: The maximum calcium loss and minimum microhardness was observed in Group 3 followed by Group 2, Group 4 and Group 1. There was a statistically significant difference between all the groups except between Groups 2 and 4. Conclusions: Irrigation with NaOCl + 2.25% PAA caused the maximum calcium loss from root dentin and reduced microhardness. A negative correlation existed between the calcium loss and reduction in the microhardness of root dentin. PMID:24778513

  13. Ionizing irradiation affects the microtensile resin dentin bond strength under simulated clinical conditions

    PubMed Central

    Yadav, Suman; Yadav, Harish

    2013-01-01

    Objectives: This study evaluated the effect of ionizing radiations on resin–dentin interface in terms of marginal adaptation and micro-tensile bond strength under thermocycling and mechanical loading. Materials and Methods: Forty extracted human mandibular third molars were divided into four groups. GR I: No Irradiation and Class II MO cavities were prepared that were restored with composite restorations; GR II: Teeth were irradiated and restored; GR III: Teeth were restored and irradiated; GR IV: Teeth were restored during irradiation dosage fractions. All samples were thermal and mechanical loaded with 5000 cycles, 5 ± 2-55 ± 2°C, dwell time 30 s and 150,000 cycles at 60N. Resin–dentin slabs were trimmed into dumbbell-shaped slabs and microtensile bond strength was measured. The bond strength data was analyzed by one-way analysis of variance test. Results and Conclusions: Irradiation before tooth preparation deteriorated the microtensile bond strength. PMID:23716968

  14. Effect of diode laser radiation in root canal wall dentine: a microbiological study

    NASA Astrophysics Data System (ADS)

    Gutknecht, Norbert; Conrads, Georg; Apel, Christian; Schubert, Claus; Lampert, Friedrich

    2000-03-01

    The aim of this study was to investigate the antibacterial effect of a diode laser in deep root canal dentine. The microbial colonization of root canal dentine can lead to failures in conventional endodontic treatment if only an inadequate bacterial reduction is achieved through canal treatment and chemical disinfection. 100 micrometer, 300 micrometer and 500 micrometer bovine dentine slices obtained by longitudinal sections were sterilized and inoculated on one side with an Enterococcus faecalis suspension. Laser radiation was performed on the opposite side with the diode laser, emits light at 810 nm and operates in the continuous wave mode (cw). Radiation was performed using a 400 micrometer tapered fiber tip at an angle of approx. 5 degrees to the surface over a period of 30 s. The output power at the distal end of the tip was 0.6 watt. The bacteria were then eluted through vibration and cultured on blood agar plates. The colony count reflected the antibacterial effect of laser radiation as a function of the layer thickness. A mean bacterial reduction of 74% was achieved even with a 500 micrometer thick slice. This investigation indicates that the diode laser can support the bacterial reduction in endodontic treatment.

  15. Effect of Citric Acid and Ethylenediaminetetraacetic Acid on the Surface Morphology of Young and Old Root Dentin

    PubMed Central

    Scelza, Miriam Zaccaro; de Noronha, Fernando; da Silva, Licinio Esmeraldo; Maurício, Marcos; Gallito, Marco Antonio; Scelza, Pantaleo

    2016-01-01

    Introduction: The aim of this in vitro study was to evaluate the effect of 10% citric acid and 17% ethylenediaminetetraacetic acid (EDTA) irrigating solutions on the surface morphology of young and old root dentin by determining the number and diameter of dentinal tubules using scanning electron microscopy (SEM). Methods and Materials: Fifty healthy human teeth collected from young (≤30 years) and old (≥60 years) individuals (n=25) were first prepared with a Largo bur #2 to produce smear layer on the root canal surface. Subsequently, the crowns and the root middle and apical thirds were sectioned and removed, and the cervical thirds were sectioned vertically in the buccal-lingual direction into two equal halves. The obtained samples were then immersed in 2.5% sodium hypochlorite for 30 min and randomly separated into two treatment groups for each age group. In each age group, ten samples were selected as controls and did not receive any type of treatment. The rest of the specimens were then rinsed, dried and treated for 4 min with 10% citric acid or 17% EDTA. The samples were then assessed with SEM regarding the number and diameter of dentinal tubules. All data were assessed using Student’s t-test. The level of significance was set at 0.05. Results: Regardless of the type of treatment, no significant differences were observed in the number of open tubules between the young and old root dentin (P>0.05). Nonetheless, the diameter of the tubules in the old root dentin was larger when 17% EDTA was used (P<0.05). Both, young and old root dentin did not differ with the 10% citric acid treatment (P>0.05). Conclusion: The results showed that 17% EDTA treatment induced a significant demineralization in old root dentin. PMID:27471529

  16. Effects of the Er, Cr:YSGG laser irradiation on dentin bond strength

    NASA Astrophysics Data System (ADS)

    Piccioni, M. A. R. V.; Neves, T. P. C.; Kubo, C. S.; Saad, J. R. C.; Campos, E. A.

    2016-02-01

    The aim of this study is to evaluate the influence of Er,Cr:YSGG laser irradiation and bur on the bond strength of different single step self-etch adhesive systems in normal and artificially hypermineralized dentin. In total, 112 human molars were selected. The specimens were randomly divided into two different groups according to the type of dentin. The teeth from each group were randomly divided into two subgroups according to the adhesive system used: Clearfil S3 Bond and Optibond All in One. Each subgroup received different treatments: (1) conditioning conventional; (2) conditioning of the dentin surface with Er,Cr:YSGG  +  application of the adhesive system; (3) ‘surface roughening’ dentin with 3098 diamond bur  +  application of the adhesive system. The matrices were positioned, filled with composite resin and photoactivated for 40 s. After a storage period of 24 h in a humid environment, the specimens were submitted to microshear bond strength testing. Subsequently, the fracture pattern of each sample was determined. One specimen per group was prepared in order to evaluate the interface and/or appearance of resin tags. The data of the microshear bond strength (μSBS) were analyzed by two-way ANOVA and Tukey’s (p  <0.05). In the hypermineralized dentin, there was no significant statistical difference between all the treatments employed, enhancing the option of employing single step self-etch adhesives in dentin sclerotic.

  17. Er:YAG laser irradiation of human dentin: Raman study of collagen

    NASA Astrophysics Data System (ADS)

    Soares, Luis E. S.; Martin, Airton A.; Brugnera, Aldo, Jr.; Zanin, Fatima; Arisawa, Emilia A.; Pacheco, Marcos T. T.

    2004-05-01

    Raman Spectroscopy was used to examine the distribution of the organic components in the human dentin before and after the chemical and thermal etching process. Polished dentin disks (n = 6/group) with 4mm thickness from twelve third molars were irradiated with Er:YAG laser. The dentin disks were prepared by polishing through a series of SiO2 papers with water and cleaned by ultrasonic system. Four pretreatment were performed. The disks were etched with 37% phoshporic acid for 15 s (group 1), Er:YAG laser 80 mJ, 3Hz, 30s. (group II), Er:YAG laser 120 mJ, 3Hz, 30s. (group III) and Er:YAG laser 180mJ, 3Hz, 30s. (group IV). The Raman spectra obtained from normal and treated dentin were analyzed. Attention was paid to the organic component (1453cm-1). Raman spectroscopy showed that the organic dentin content were more affected in autoclaved teeth than in the specimens treated by Thymol. Peak area reduction in the specimens treated by Thymol in group I and II showed to be the most conservative procedures regarding to changes in organic dentin components. Pulse energies of 120 and 180 mJ showed to preduce more reduction in the organic content associated with more reduction in the peak areas at 1453 cm-1.

  18. Raman study of human dentin irradiated with Er:YAG laser

    NASA Astrophysics Data System (ADS)

    S. Soares, Luis E.; Martin, Airton A.; Brugnera, Aldo, Jr.; Zanin, Fatima A.; Arisawa, Emilia A.; T. Pacheco, Marcos T.

    2004-09-01

    Raman Spectroscopy was used to examine the distribution of the mineral and organic components in the human dentin before and after the chemical and thermal etching process. Polished dentin disks (n = 6/group) with 4mm thickness from twelve third molars were irradiated with Er:YAG laser. The dentin disks were prepared by polishing through a series of SiO2 papers with water and cleaned by ultrasonic system. Four pretreatment were performed. The disks were etched with 37% phosphoric acid (group I), Er:YAG laser 80mJ, 3Hz, 30s. (group II), Er:YAG laser 120mJ, 3Hz, 30s. (group III) and Er:YAG laser 180mJ, 3Hz, 30s. (group IV). The Raman spectra obtained from normal and treated dentin were analyzed. Attention was paid to the mineral PO4 (962 cm-1), CO3 (1073 cm-1) and to the organic component (1453cm-1). Raman spectroscopy showed that the mineral and organic dentin content were more affected in autoclaved teeth than in the specimens treated by Thymol. Peak area reduction in the specimens treated by Thymol in group I and II showed to be the most conservative procedures regarding to changes in organic and inorganic dentin components. Pulse energies of 120 and 180mJ showed to produce more reduction in the organic and inorganic content associated with more reduction in the peak areas at 960 and 1453cm-1.

  19. Effect of various laser irradiations on the mineral content of dentin

    PubMed Central

    Dilber, Erhan; Malkoc, Meral Arslan; Ozturk, A. Nilgun; Ozturk, Firat

    2013-01-01

    Objective: The aim of this study was to evaluate the mineral content of dentin irradiation with Erbium: yttrium-aliminum-garnet (Er:YAG), Neodmiyum:yttrium-aliminum garnet (Nd:YAG) and potassium titanium phosphate (KTP) laser used for in the treatment of dentin hypersensitivity. Methods: Six extracted wisdom, unerupted molar teeth were used in this study. The enamel of the teeth was removed with a conventional bur under water cooling to expose the dentin surface. The teeth were mounted in a slow-speed, diamond-saw, sectioning machine. Two dentin slabs were obtained from each tooth and each slab was sectioned so that 4 slabs were made from each teeth. Then dentin slabs were randomly divided into four groups. Group A: Control Group, Group B: Er:YAG laser, Group C: Nd:YAG laser, Group D: KTP laser. The levels of Ca, K, Mg, Na,P and Ca/P mineral ratio in each dentin slab were measured by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Data were analysed by one way analysis of variance (ANOVA) and Tukey HSD tests. One sample from each group was prepared for scanning electron microscopy (SEM). Results: There were no significant differences between the groups for Ca, K, Mg, Na,P and Ca/P mineral ratio (P>.05). SEM photographs indicated that there were melted areas around the exposed dentin tubules in groups treated with Er:YAG and KTP lasers. Conclusion: This study demonstrated that laser etching with the Er:YAG, Nd:YAG, KTP laser systems did not affect the compositional structure of the dentin surfaces. PMID:23407579

  20. Strain Distribution in Root Surface Dentin of Maxillary Central Incisors during Lateral Compaction

    PubMed Central

    Pilo, Raphael; Metzger, Zvi; Brosh, Tamar

    2016-01-01

    Aim To precisely quantify the circumferential strains created along the radicular dentin of maxillary incisors during a simulated clinical procedure of lateral compaction. Methods Six miniature strain gauges were bonded on the roots of fourteen recently extracted maxillary central incisors that were subjected to root canal instrumentation. The strain gauges were bonded at three levels (apical, middle, and coronal) and four aspects (buccal, lingual, mesial, and distal) of the roots. Each tooth was embedded in a PVC cylinder containing polyvinyl-siloxane impression material. Root filling was then performed by simulating the clinical procedure of lateral compaction using nickel-titanium finger spreaders. The force applied to the spreader and the strains developing in the surface root dentin were continuously recorded at a frequency of 10 Hz. Results The highest strains that developed during lateral compaction were in the mesial and distal aspects at the apical level of the root. The magnitudes of the maximal mesial/distal strains at the apical as well as the mid-root levels were approximately 2.5–3 times higher than those at the buccal/lingual aspects (p = 0.041). The strains decreased significantly (p<0.04) from the apical through the mid-root levels to the coronal level, yielding gradients of 2.5- and 6-fold, respectively. The mesial and distal strains were consistently tensile and did not differ significantly; however, the buccal strains were generally 35–65% higher than the lingual strains (p = 0.078). Lateral compaction resulted in the gradual build-up of residual strains, resulting in generation of a 'stair-step' curve. These strains declined gradually and almost completely disappeared after 1000 sec. Conclusions With proper mounting of several miniature strain gauges at various levels and aspects of the root, significant circumferential strains can be monitored under clinically relevant compaction forces. The residual strains at the end of lateral

  1. Influence of endodontic sealer composition and time of fiber post cementation on sealer adhesiveness to bovine root dentin.

    PubMed

    Rosa, Ricardo Abreu da; Barreto, Mirela Sangoi; Moraes, Rafael do Amaral; Broch, Juliana; Bier, Carlos Alexandre Souza; Só, Marcus Vinícius Reis; Kaizer, Osvaldo Bazzan; Valandro, Luiz Felipe

    2013-01-01

    This study aimed to assess the influence of the type of endodontic sealer (salicylate resin-based sealer vs. two endodontic sealers) and the time of fiber post cementation after root filling on the post adhesion to bovine root dentin. Sixty bovine roots were assigned to six groups (n=10), considering an experimental design with two factors (factorial 3x2): endodontic sealer factor in three levels [epoxy resin-based sealer (AH Plus), eugenol-based sealer (Endofill), and salicylate resin-based sealer plus mineral trioxide aggregate - MTA (MTA Fillapex)] and time for post cementation factor in two levels (immediate post cementation or 15 days after root canal filling). After post cementation, 2-mm-thick slices were produced and submitted to push-out test. The failure modes were analyzed under a 40× stereomicroscope and scored as: adhesive at cement/dentin interface; adhesive at cement/post interface; cement cohesive; post cohesive; dentin cohesive; or mixed. Data were analyzed using two-way ANOVA and Tukey's post-hoc tests (α=0.05). When the fiber posts were cemented immediately after the root canal filling, the bond strengths were similar, independent of the endodontic sealer type. However, after 15 days, the epoxy resin-based sealer presented higher bond strength than the other sealers (p<0.05). Comparison between each sealer in different experimental times did not reveal any differences. The main failure type was adhesive at dentin/cement interface (89.4%). The time elapsed between the root canal filling and post cementation has no influence on post/root dentin adhesion. On the contrary, the type of endodontic sealer can influence the adhesion between fiber posts and root dentin. PMID:23969913

  2. Bacterial invasion in root cementum and radicular dentin of periodontally diseased teeth in humans. A reservoir of periodontopathic bacteria.

    PubMed

    Adriaens, P A; De Boever, J A; Loesche, W J

    1988-04-01

    In this study the viability and the distribution of bacteria within the radicular dentin and pulp of periodontally diseased caries-free teeth were studied. Healthy teeth served as controls. Samples were obtained from the pulp tissue and from the radicular dentin. Dentin samples were taken from the interdental surfaces in the subgingival area. Starting from the pulpal side, three to five successive dentin layers of approximately 1 mm thickness were sampled. The samples were processed and cultured using an anaerobic technique. Bacterial growth was detected in 87% of the periodontally diseased teeth. In 83% of the teeth, bacteria were present in at least one of the dentin layers. Fifty-nine percent of the diseased teeth, from which the pulp tissue was cultured, contained bacteria in the pulp samples. The mean bacterial concentrations in the pulp and dentin layers ranged from 1,399 to 16,537 colony-forming units (CFU) per mg of tissue. These concentrations were 259 to 7,190 times greater than concentrations found in healthy teeth. It is suggested that the roots of periodontally diseased teeth could act as bacterial reservoirs from which recolonization of mechanically treated root surfaces can occur, as well as infection of the dental pulp. These findings might change current concepts concerning root surface debridement in periodontal therapy. PMID:3164373

  3. Decalcifying effects of antimicrobial irrigating solutions on root canal dentin

    PubMed Central

    Perez-Heredia, Mercedes; Baca, Pilar; Arias-Moliz, María T.; González-Rodríguez, María P.

    2013-01-01

    Objective: The aim of this study was to determine the decalcifying efficacy of 7% maleic acid (MA), 2% chlorhexidine (CHX), and combinations of 7% MA + 0.2% cetrimide (CTR) and 2% CHX + 0.2% CTR, in four time periods. Study Design: Four specimens per tooth were obtained from a 2-mm thick slice of the cervical third of the root of ten human incisors. At 1, 2, 3 and 5 minutes of immersion, the concentrations of Ca2+ were measured by atomic absorption spectrophotometry. The results were analyzed using the Mann-Whitney U-test. Results: Statistically significant differences were seen for the extracted calcium in all time periods. The amount of calcium extracted by 7% MA was the highest at all four immersion times, followed by 7% MA + 0.2% CTR. Two percent CHX and its combination with 0.2% CTR extracted virtually no calcium. Conclusions: The decalcifying capacity of 7% MA and 2% CHX diminished when combined with 0.2% CTR. Key words:Cetrimide; chlorhexidine; decalcification; maleic acid; spectrometry. PMID:22926482

  4. Root maturation and dentin-pulp response to enamel matrix derivative in pulpotomized permanent teeth.

    PubMed

    Darwish, Sherif S; Abd El Meguid, Shadia H; Wahba, Nadia A; Mohamed, Ahmed A-R; Chrzanowski, Wojciech; Abou Neel, Ensanya A

    2014-01-01

    The success of pulpotomy of young permanent teeth depends on the proper selection of dressing materials. This study aimed to evaluate the histological and histomorphometric response of dentin-pulp complex to the enamel matrix derivative (Emdogain(®) gel) compared to that of calcium hydroxide when used as a pulp dressing in immature young permanent dogs' teeth. Dentin-like tissues bridging the full width of the coronal pulp at the interface between the injured and healthy pulp tissues were seen after 1 month in both groups. With time, the dentin bridge increased in thickness for calcium hydroxide but disintegrated and fully disappeared for Emdogain-treated group. Progressive inflammation and total pulp degeneration were only evident with Emdogain-treated group. The root apices of Emdogain-treated teeth became matured and closed by cementum that attached to new alveolar bone by a well-oriented periodontal ligament. In young permanent dentition, Emdogain could be a good candidate for periodontium but not dentino-pulpal complex regeneration. PMID:24551447

  5. Characterization of caries progression on dentin after irradiation with Nd:YAG laser by FTIR spectroscopy and fluorescence imaging

    NASA Astrophysics Data System (ADS)

    Ana, P. A.; Brito, A. M. M.; Zezell, D. M.; Lins, E. C. C. C.

    2015-06-01

    Considering the use of high intensity lasers for preventing dental caries, this blind in vitro study evaluated the compositional and fluorescence effects promoted by Nd:YAG laser (λ=1064 nm) when applied for prevention of progression of dentin caries, in association or not with topical application of acidulated phosphate fluoride (APF). Sixty bovine root dentin slabs were prepared and demineralized by 32h in order to create early caries lesions. After, the slabs were distributed into six experimental groups: G1- untreated and not submitted to a pH-cycling model; G2- untreated and submitted to a pH-cycling model; G3- acidulated phosphate fluoride application (APF); G4- Nd:YAG irradiation (84.9 J/cm2, 60 mJ/pulse); G5- treated with Nd:YAG+APF; G6- treated with APF+Nd:YAG. After treatments, the samples of groups G2 to G6 were submitted to a 4-day pH-cycling model in order to simulate the progression of early caries lesions. All samples were characterized by the micro-attenuated total reflection technique of Fourier transformed infrared spectroscopy (μATR-FTIR), using a diamond crystal, and by a fluorescence imaging system (FIS), in which it was used an illuminating system at λ= 405±30 nm. Demineralization promoted reduction in carbonate and phosphate contents, exposing the organic matter; as well, it was observed a significant reduction of fluorescence intensity. Nd:YAG laser promoted additional chemical changes, and increased the fluorescence intensity even with the development of caries lesions. It was concluded that the compositional changes promoted by Nd:YAG, when associated to APF, are responsible for the reduction of demineralization progression observed on root dentin.

  6. Bond strength and SEM observation of CO2 laser irradiated dentin, bonded with simplified-step adhesives.

    PubMed

    Koshiro, K; Inoue, S; Niimi, K; Koase, K; Sano, H

    2005-01-01

    This study investigated, mechanically and morphologically, whether the dentin surface irradiated by CO2 laser could be a possible adherent when bonded with simplified-step adhesives. Buccal enamel and cementum of extracted human premolars were removed to expose a flat dentin surface. The dentin surfaces were irradiated continuously with CO2 laser at 1.0 W. Before bonding with either a single-bottle adhesive (Single Bond) or a self-etching priming system (Mega Bond), the irradiated dentin surface was treated as follows: no treatment, NaHCO3 powder abrasion and wet-grinding with 600-grit SiC paper. The treated dentin surfaces were bonded to resin composite with either of the two adhesives. Non-irradiated dentin surfaces were also used as control. Resin bonded specimens were stored in water at 37 degrees C for 24 hours and subjected to microtensile bond test. Additionally, to observe the resin/irradiated dentin interface, resin-bonded specimens were similarly prepared, sectioned into slabs, embedded in epoxy resin, polished with diamond pastes, sputter coated Au-Pd and examined with scanning electron microscopy (SEM). After SEM observation, the specimens were further polished with diamond paste to remove the Au-Pd sputter-coat, immersed in HCL and NaOCl and finally observed by SEM again. In the presence of carbonized dentin, microtensile bond strength drastically decreased but recovered to the control value by removing the carbonized dentin layer visually with SiC paper for both adhesive systems. However, the laser-affected dentin that remained on the bonded interface was easily dissolved with NaOCl and HCl. PMID:15853101

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

    NASA Astrophysics Data System (ADS)

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

    2002-06-01

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

  8. Root dentin strain and temperature rise during endodontic treatment and post rehabilitation.

    PubMed

    Amade, Euridsse Sulemane; Novais, Veridiana Resende; Roscoe, Marina Guimarães; Azevedo, Fabiane Maria Ferreira; Bicalho, Aline Aredes; Soares, Carlos José

    2013-01-01

    This study investigated the effects of endodontic treatment procedures and different post systems rehabilitation steps on the strain and temperature rise on apical and cervical root dentin regions. Twenty-one extracted human canine teeth had two strain gages attached to the distal root surface and two thermocouples attached to the mesial root surface (cervical and apical). The strain and temperature rise were recorded during the following procedures: root canal preparation, final rinse and drying, root canal filling and canal relief. Then the teeth were divided into three groups (n=7), according to the type of post system: CPC, cast post and core; FGP, fiberglass post; and PSP, prefabricated steel post. Data continued to be recorded during the post space preparation, post modeling (only for CPC), post trying and post cementation. Data were subjected to a two-way ANOVA followed by Tukey's test (α=0.05). The post-space preparation caused the highest temperature rise (4.0-14.9 °C) and the highest strain in the apical region during irrespective of post type. The resin cement light-activation resulted in significant temperature increases in the cervical region for all of the groups. The canal relief and the post-space preparation produced highest temperature rises. The CPC post modeling resulted in higher root strain level similarly the level of post preparation. The PSP resulted in highest strain during post trying and post cementation. PMID:24474355

  9. Shear bond strength of novel calcium aluminate-based cement (EndoBinder) to root dentine

    PubMed Central

    Garcia, Lucas da Fonseca Roberti; Rossetto, Hebert Luis; Pires-de-Souza, Fernanda de Carvalho Panzeri

    2014-01-01

    Objective: To evaluate the shear bond strength of a novel calcium aluminate-based cement, EndoBinder (EB), to dentine in comparison with Grey and White Mineral Trioxide Aggregate (MTA). Materials and Methods: Root canal hemi-sections obtained from 30 extracted molar teeth were embedded in self-polymerized acrylic resin and were grounded wet in order to obtain a flat dentine surface. Next, the roots were randomly assigned into three groups (n = 10), according to the cement used, as follows: EB: EndoBinder; WMTA: White MTA and GMTA: Grey MTA. The shear bond strength test was performed using a Universal Testing Machine (0.5 mm/min) and the data were submitted to statistical analysis (1-way ANOVA and Tukey tests, P < 0.05). Results: EB presented the highest shear bond strength values; however, there was no statistically significant difference in comparison with GMTA (P > 0.05). WMTA presented the lowest mean values, which were significant in comparison with EB (P < 0.05). Conclusions: The novel calcium aluminate-based cement presented higher shear bond strength than WMTA, and should be considered as a promising alternative in endodontic therapy. PMID:25512731

  10. The effects of different nickel-titanium instruments on dentinal microcrack formations during root canal preparation

    PubMed Central

    Ustun, Yakup; Aslan, Tugrul; Sagsen, Burak; Kesim, Bertan

    2015-01-01

    Objective: The aim of the present study was to investigate the incidence of dentinal microcracks caused by different preparation techniques. Materials and Methods: 120 extracted human mandibular incisor teeth were divided into five experimental groups and one control group (n = 20): Group 1: Hand preparation with balanced force technique up to #25 K-file. Group 2: Preparation with only ProTaper F2 instrument in a reciprocating movement. Group 3: Preparation with Reciproc R25 instrument in a reciprocating movement. Group 4: Preparation with ProTaper instruments up to F2 instrument. Group 5: Preparation with ProTaper Next instruments up to X2 instrument. No procedure was applied to control group. The roots were sectioned horizontally at 3, 6 and 9 mm from the apex and examined. Absence or presence of dentinal microcracks was noted. Results: The Chi-square test was performed to compare the appearance of cracked roots between all groups. There were no significant differences among the groups (P > 0.05). Conclusions: In conclusion, except the hand file and control group, all experimental groups showed microcrack formations. PMID:25713483

  11. Evaluation of Chlorine Dioxide Irrigation Solution on the Microhardness and Surface Roughness of Root Canal Dentin.

    PubMed

    Ballal, Nidambur Vasudev; Khandewal, Deepika; Karthikeyan, Saravana; Somayaji, Krishnaraj; Foschi, Federico

    2015-12-01

    The aim of this study was to evaluate the effect of chlorine dioxide and various other more common irrigation solutions on the microhardness and surface roughness of root canal dentin. Fifty human maxillary central incisors were sectioned longitudinally and treated for 1 minute with 5 ml of the following aqueous solutions (v/v%): Group 1: 13.8% chlorine dioxide, Group 2: 17% ethylene diamine tetraacetic acid (EDTA). Group 3: 7% maleic acid, Group 4: 2.5% sodium hypochlorite (5 ml/min), Group 5: Saline (control). Specimens were subjected to microhardness and surface roughness testing. Chlorine dioxide and sodium hypochlorite reduced the microhardness more than other test agents. The highest surface roughness was produced with maleic acid. Chlorine dioxide should be used cautiously during chemomechanical preparation of the root canal system in order to prevent untoward damage to the teeth. PMID:26767238

  12. Evaluation of Chlorine Dioxide Irrigation Solution on the Microhardness and Surface Roughness of Root Canal Dentin.

    PubMed

    Ballal, Nidambur Vasudev; Khandewal, Deepika; Karthikeyan, Saravana; Somayaji, Krishnaraj; Foschi, Federico

    2015-09-01

    The aim of this study was to evaluate the effect of chlorine dioxide and various other more common irrigation solutions on the microhardness and surface roughness of root canal dentin. Fifty human maxillary central incisors were sectioned longitudinally and treated for 1 minute with 5 ml of the following aqueous solutions (v/v%): Group 1:13.8% chlorine dioxide, Group 2:17% ethylene diamine tetraacetic acid (EDTA). Group 3: 7% maleic acid, Group 4: 2.5% sodium hypochlorite (5ml/min), Group 5: Saline (control). Specimens were subjected to microhardness and surface roughness testing. Chlorine dioxide and sodium hypochlorite reduced the microhardness more than other test agents. The highest surface roughness was produced with maleic acid. Chlorine dioxide should be used cautiously during chemomechanical preparation of the root canal system in order to prevent untoward damage to the teeth. PMID:26591249

  13. Dentinal defects before and after rotary root canal instrumentation with three different obturation techniques and two obturating materials

    PubMed Central

    Kumaran, Ponnuswamy; Sivapriya, Elangovan; Indhramohan, Jamuna; Gopikrishna, Velayutham; Savadamoorthi, K Subramani; Pradeepkumar, Angambakkam Rajasekharan

    2013-01-01

    Aim: To evaluate the role of rotary root canal instrumentation followed by obturation with three different techniques and two different materials on the incidence of dentinal defects. Materials and Methods: One hundred and sixty mandibular premolars were divided into eight groups (n = 20). Group I was left untreated and served as control. The other seven groups were prepared with profile rotary instruments till #40.06 taper. After preparation, group II was left unfilled, groups III, IV, and V were obturated with Gutta-percha and AH Plus sealer using passive technique, lateral compaction and warm vertical compaction, respectively. Groups VI, VII, and VIII were obturated with Resilon and Realseal sealer using passive technique, lateral compaction, and warm vertical compaction, respectively. Roots were then sectioned at 3, 6, and 9 mm from the apex and inspected under a stereomicroscope (50×) for dentinal defects. Chi-square test was performed to compare the incidence of dentinal defects between the groups (P < 0.05). Results: The unprepared control group had no dentinal defects. The instrumentation group (group II) and the obturation group (groups III-VIII) showed significantly more defects than the uninstrumented control group (group I) (P < 0.001). There was no significant difference between the root canal obturating techniques (group III-VIII) when compared with the instrumentation group (group II). On inter group comparison among the obturation groups the number of defects after lateral compaction with Gutta-percha (group IV) was significantly larger than passive Gutta-percha obturation (group III) (P < 0.05). Conclusions: The results suggest that root canal instrumentation significantly influenced the incidence of dentinal defects or fracture. Dentinal defects were more significantly attributed to the role of root canal instrumentation rather than the type of obturation technique or material. Lateral compaction with Gutta-percha significantly produces more

  14. Morphological analysis of the retrofilled apical dentin surfaces irradiated with CO2 laser

    NASA Astrophysics Data System (ADS)

    Aun, Carlos E.; Lage-Marques, Jose L.; Gavini, Giulio; Clasen, Naya F.; Matsumoto, Koukichi

    1998-04-01

    Countless researches conducted in these last years have compared the sealing capacity of various materials for retrofillings. Besides, the association of laser irradiation to traditional procedures inquires to increase the success of this kind of treatment. The purpose of this study was to evaluate the morphological changes on dentin surface and the junction between retrofilling material and apical cavity, with different materials irradiated or not with CO2 laser, in scanning electron microscopy. The following materials were used: Group A yields Super EBA; group B yields Super EBA and CO2 laser irradiation (Luxar System); group C yields Glass Ionomer Cement; group D yields Glass Ionomer Cement and CO2 laser. In groups B and D the power set was 2 watts, 20 msec, with a CT3105 ceramic point, and the power density for the CO2 laser application was 397,93 w/cm2. The morphological analysis permitted to conclude that the dentin laser irradiation showed different and less intense superficial alteration when compared with retrofilling materials. In most cases, the alterations to the material surfaces showed cavities and craters. Group B presented more irregular and affected surfaces, creating blank spaces in the adjacent areas to the radicular dentinal surfaces after laser application, probably because of the carbonization.

  15. Chemical and morphological changes in human dentin after Er:YAGlaser irradiation: EDS and SEM analysis.

    PubMed

    Contreras-Arriaga, Belinda; Rodríguez-Vilchis, Laura Emma; Contreras-Bulnes, Rosalía; Olea-Mejìa, Oscar Fernando; Scougall-Vilchis, Rogelio José; Centeno-Pedraza, Claudia

    2015-11-01

    Sixty samples of human dentin were divided into six groups (n = 10) and were irradiated with Er:YAG laser at 100 mJ-19.9 J/cm(2), 150 mJ-29.8 J/cm(2), 100 mJ-35.3 J/cm(2), 150 mJ-53.0 J/cm(2), 200 mJ-70.7 J/cm(2), and 250 mJ-88.5 J/cm(2), respectively, at 7 Hz under a water spray. The atomic percentages of carbon, oxygen, magnesium, calcium, and phosphorus and the Ca-to-P molar ratio on the dentin were determined by energy dispersive X-ray spectroscopy. The morphological changes were observed using scanning electron microscopy. A paired t-test was used in statistical analysis before and after irradiation, and a one-way ANOVA was performed (P ≤ 0.05). The atomic percent of C tended to decrease in all of the groups after irradiation with statistically significant differences, O and Mg increased with significant differences in all of the groups, and the Ca-to-P molar ratio increased in groups IV, V, and VI, with statistically significant differences between groups II and VI. All the irradiated samples showed morphological changes. Major changes in the chemical composition of dentin were observed in trace elements. A significant increase in the Ca-to-P ratio was observed in the higher energy density groups. Morphological changes included loss of smear layer with exposed dentinal tubules. The changes produced by the different energy densities employed could have clinical implications, additional studies are required to clarify them. PMID:26397964

  16. Effect of various concentrations of tetracycline hydrochloride demineralization on root dentin surface: A scanning electron microscopic study

    PubMed Central

    Penmatsa, Tanuja; Varma, Satish; Mythili; Rao, Killi Prabhakar; Kishore, Trinath; Bindu, Hima

    2013-01-01

    Introduction: Within the last 20 years root demineralization has attracted attention as a periodontal regenerative technique. Topical tetracycline application has been widely reported for use as a conditioner, to decontaminate the root surface and to promote periodontal regeneration. The purpose of this scanning electron microscopic (SEM) study is to evaluate the surface characteristics of demineralized diseased and non-diseased dentine root surfaces using different concentrations of tetracycline hydrochloride (TTC-HCl). Material and Methods: This SEM study was carried out in 20 dentin samples obtained from non-diseased human premolars and 20 dentin samples obtained from diseased human premolars. Pure TTC-HCl was applied to the dentin surface at 50 mg/ml, 100 mg/ml and 150 mg/ml concentrations for 3 min in experimental groups while distilled (0 mg/ml) water was applied to the control groups. Statistical Analysis: Mean and standard deviation were estimated from the sample for each study group. Mean values were compared by either one-way ANOVA with Tukey-Honestly significant difference procedure or Kruskal - Wallis one way ANOVA with Mann-Whitney u-test. Further Student′s independent t-test/Mann-Whitney u-test was used appropriately to compare the mean values between two independent groups. Results: In the present study using 100 mg/ml tetracycline seems to be more effective on both diseased and non-diseased dentin surfaces. Conclusions: The results of this study confirm that pure TTC-HCl conditioning produced comparable surface characteristics on dentin of both diseased and non-diseased roots with 100 mg/ml concentration for 3 min. PMID:23946576

  17. Influence of adhesive systems on microtensile bond strength of resin-based endodontic sealers to the root dentin

    PubMed Central

    Rodríguez-Martínez, Juan B.; González-Rodríguez, María P.; González-López, Santiago

    2014-01-01

    Objective: The aim of this study was to determine the microtensile bond strength to root dentin of AH Plus™ and EndoREZ® with Clearfil Liner Bond 2V and Optibond Solo™ Plus adhesive systems. Study Design: The coronal and middle thirds of six single rooted bovine teeth was split longitudinally in a mesio-distal direction. The two halves were joined with AH Plus or EndoREZ, with and without the use of Clearfil Liner Bond 2V and Optibond Solo™ Plus adhesive systems. Build-ups were vertically sectioned into quadrangular (≈1mmx1mm) compound bars and subjected to tensile tests at a constant crosshead speed (1 mm/min) until debonding. Results: Optibond® Solo Plus™ in combination with AH Plus™ and EndoREZ® showed the highest mean microtensile bond strength values, in both coronal and middle thirds. The lowest results were seen in the groups where no dentine adhesive was applied, and in those where the self-etching adhesive Clearfil Liner Bond 2V was used. Conclusion: The microtensile bond strength to root dentin of AH Plus™ and EndoREZ may be increased with the use of a total-etch adhesive. Key words:Adhesive systems, AH Plus, EndoREZ, microtensile bond strength, root dentin. PMID:25136417

  18. Geometric factors affecting dentin bonding in root canals: a theoretical modeling approach.

    PubMed

    Tay, Franklin R; Loushine, Robert J; Lambrechts, Paul; Weller, R Norman; Pashley, David H

    2005-08-01

    Cavity configuration factor (C-factor) is the ratio of the bonded surface area in a cavity to the unbonded surface area. In a box-like class I cavity, there may be five times more bonded surface area than the unbonded surface area. During polymerization, the volume of monomers is reduced, which creates sufficient shrinkage stresses to debond the material from dentin, thereby decreasing retention and increasing leakage. The important variables influencing bonding adhesive root-filling materials to canals was examined using a truncated inverted cone model. C-factors in bonded root canals exhibit a negative correlation with sealer thickness. For a 20 mm-long canal prepared with a size 25 file, calculated C-factors ranged from 46 to 23,461 with decreasing sealer thickness (500-1 microm), compared to a C-factor of 32 when the canal was filled only with sealer. As the thickness of the adhesive is reduced, the volummetric shrinkage is reduced, which results in a reduction in shrinkage stress (S-factor). C-factors above 954 calculated with sealer thickness smaller than 25 microm are partially compensated by increases in bonding area and decreases in shrinkage volume. However, the interaction of these two geometrically related factors (C- and S-factors) predicts that bonding of adhesive root-filling materials to root canals is highly unfavorable when compared with indirect intracoronal restorations with a similar resin film thickness. PMID:16044041

  19. Cariostatic effect of fluoride-containing restorative materials associated with fluoride gels on root dentin

    PubMed Central

    BORGES, Fernanda Tavares; CAMPOS, Wagner Reis da Costa; MUNARI, Lais Sant'ana; MOREIRA, Allyson Nogueira; PAIVA, Saul Martins; MAGALHÃES, Claudia Silami

    2010-01-01

    Secondary caries is still the main cause of restoration replacement, especially on the root surface Objective This in vitro study evaluated the cariostatic effects of fluoride-containing restorative materials associated with fluoride gels, on root dentin. Materials and Methods A randomized complete block design was used to test the effects of the restorative systems, fluoride regimes and the interactions among them at different distances from restoration margins. Standardized cavities were prepared on 240 bovine root specimens and randomly assigned to 15 groups of treatments (n=16). Cavities were filled with the following restorative materials: Ketac-Fil (3M-ESPE); Vitremer (3M-ESPE); Dyract/Prime & Bond NT (Dentsply); Charisma/Gluma One Bond (Heraeus Kulzer) and the control, Z250/Single Bond (3M-ESPE). The specimens were subjected to a pH-cycling model designed to simulate highcaries activity. During the cycles, 1.23% acidulated phosphate fluoride, 2.0% neutral sodium fluoride or deionized/distilled water (control) was applied to the specimens for 4 min. The surface Knoop microhardness test was performed before (KHNi) and after (KHNf) the pH cycles at 100, 200 and 300 mm from the margins. Dentin microhardness loss was represented by the difference in initial and final values (KHNi - KHNf). Data were analyzed by Friedman's and Wilcoxon's tests, ANOVA and Tukey's test (α=5%). Results The interaction of restorative systems and topical treatments was not significant (p=0.102). Dentin microhardness loss was lowest closer to the restoration. Ketac-fil presented the highest cariostatic effect. Vitremer presented a moderate effect, while Dyract and Charisma did not differ from the control, Z250. The effects of neutral and acidulated fluoride gels were similar to each other and higher than the control. Conclusion Conventional and resin-modified glass ionomer cements as well as neutral and acidulated fluoride gels inhibit the progression of artificial caries adjacent to

  20. Antimicrobial activity and substantivity of Uncaria tomentosa in infected root canal dentin.

    PubMed

    Herrera, Daniel Rodrigo; Durand-Ramirez, Jorge Enrique; Falcão, Amanda; Silva, Emmanuel João Leal Nogueira da; Santos, Elizabete Brasil Dos; Gomes, Brenda Paula Figueiredo de Almeida

    2016-01-01

    The aim of this study was to analyze the antimicrobial activity and substantivity of Uncaria tomentosa Willd DC (cat's claw, CC) in root dentin contaminated with Enterococcus faecalis. Forty-eight human premolars were contaminated with E. faecalis (ATCC 29212) and randomly divided into four groups according to the irrigant used during chemomechanical preparation (CMP): CC group: 2% CC gel; CHX group: 2% chlorhexidine digluconate gel (CHX); NaOCl group: 5.25% sodium hypochlorite (NaOCl); and SS group: sterile saline (SS). Microbiological samples were collected before (S1) and after (S2) CMP and after 7 days (S3). Colony-forming units (CFU/mL) at the different sampling times and comparisons among the groups were statistically analyzed by Wilcoxon and Kruskal-Wallis tests (p < 0.05). Significant bacterial reduction was achieved in all groups after CMP (p < 0.05). Results show no significant difference between S3 and S2 (p > 0.05) in the CC and CHX groups. Bacterial load was higher in S3 than in S2 samples (p < 0.05) in the NaOCl and SS groups. Our results suggest antibacterial effect of 2% CC gel against E. faecalis in infected dentin, in addition to antibacterial substantivity of 2% CC and 2% CHX up to 7 days. PMID:27119588

  1. Penetration of Sodium Hypochlorite Modified with Surfactants into Root Canal Dentin.

    PubMed

    Palazzi, Flavio; Blasi, Andrea; Mohammadi, Zahed; Fabbro, Massimo Del; Estrela, Carlos

    2016-04-01

    The aim of this study was to evaluate the effect of concentration, exposure time and temperature of sodium hypochlorite (NaOCl) added with surfactants on its penetration into dentinal tubules. Sixty-five extracted human permanent maxillary anterior teeth with single canals were prepared by ProTaper SX hand-operated instruments. The teeth were then sectioned perpendicular to the long axis. The crowns and apical thirds of all the teeth were removed. The remaining roots were processed into 4-mm-long blocks and stained overnight in crystal violet. One hundred and thirty stained blocks were further split into halves and treated by nine different types of NaOCl-based solutions. Three solutions were added with surfactants (Hypoclean, H6, Chlor-Xtra) and the others were regular hypochlorites at increasing concentrations (1%, 2%, 4%, 5.25%, <6%, 6% NaOCl) from different brands. The dentin blocks were exposed to the solutions for 2, 5, and 20 min at 20 °C, 37 °C and 45 °C, respectively. The depth of NaOCl penetration was determined by bleaching of the stain and measured by light microscopy at 20 and 40. Statistical comparisons were made by using a generalized linear model with Bonferroni's post-hoc correction. The shortest penetration (81±6.6 μm) was obtained after incubation in 1% NaOCl for 2 min at 20 °C; the highest penetration (376.3±3.8 μm) was obtained with Chlor-Xtra for 20 min at 45 °C. Varying NaOCl concentration produced a minimal effect while temperature and exposure time had a significant direct relationship with NaOCl penetration into dentinal tubules, especially those with lowered surface tension. The exposure time and temperature of sodium hypochlorite as well as the addition of surfactants may influence the penetration depth of irrigants into dentinal tubules. PMID:27058386

  2. In vitro effect of hesperidin on root dentin collagen and de/re-mineralization.

    PubMed

    Islam, Sofiqul Md; Hiraishi, Noriko; Nassar, Mohannad; Sono, Ryohei; Otsuki, Masayuki; Takatsura, Tsutomu; Yiu, Cynthia; Tagami, Junji

    2012-01-01

    The aims of this study were to investigate the effects of hesperidin, a citrus flavonoid, on human root dentin demineralization and collagen preservation, and compare it with chlorhexidine and grape seed extract. Specimens were assigned to different treatment groups: hesperidin, chlorhexidine and grape seed extract. Specimens were subjected to pH cycling by demineralization for 14 h, incubation in testing solutions for 2 h and remineralization in presence of bacterial-derived collagenase for 8 h, for 8 days. Calcium release was measured by means of an atomic absorption spectrophotometer, and degraded collagen matrix was investigated by hydroxyproline assay. Specimens were assessed longitudinally with transverse micro-radiography to investigate lesion depth and mineral loss. In hesperidin and grape seed extract groups, demineralization was reduced when the collagen matrix was preserved. The hesperidin group showed the lowest value in lesion depth and mineral loss, indicating that hesperidin inhibited demineralization and probably enhanced remineralization even under fluoride-free conditions. PMID:22673464

  3. Effect of different post-space pretreatments on fiber post bonding to root dentine

    PubMed Central

    Alaghemand, Homayon; Mirzae, Mansoreh; Ahmadi, Elham; Saidi, Akam

    2013-01-01

    Background: Before the resin bond endodontic post-cementation, various solutions are used to improve bond strength of these posts to root dentine. The purpose of this study was to evaluate the effect of the different pre-treatments (ethanol, ethylene de amine tetra acetic acid [EDTA] and EDTA + ethanol) on the bond strength of adhesively lutted tooth colored fiber post. Materials and Methods: Forty-eight human anterior teeth (incisor and canine) were selected in this experimental study. The species were endodontically treated, and the post-space was prepared. The species were randomly divided into four groups of 12 teeth in each and were treated as follows: (i) 0.1 M EDTA, (ii) 99.6% ethanol, (iii) 0.1 M EDTA followed by 99.6% ethanol and (iv) without any treatment (control). A push-out test was carried out after 24 h. Each tooth was cut into three 1 mm-thick sections. Fracture type was assessed using stereomicroscope. The data were analyzed by one way-ANOVA followed by Scheffe post-hoc test at P = 0.05. Results: Almost, in EDTA and (EDTA + ethanol) every sample failed at the interface between post and lutting cement. Predominant failure mode in ethanol and control group was mixed failure. The surface treatment methods did not have any significant effect (P > 0.05) on any group but EDTA group had the highest bond strength. Conclusion: Surface treatment with (ethanol, EDTA, and EDTA + ethanol) does not significantly appear to be effective in improving the bond strength of fiber posts into root dentine. The highest bond strength was observed in EDTA group and the lowest in the control group. PMID:24130594

  4. Evaluation of dentinal defect formation after root canal preparation with two reciprocating systems and hand instruments: an in vitro study

    PubMed Central

    Helvacioglu-Yigit, Dilek; Aydemir, Seda; Yilmaz, Ayca

    2015-01-01

    The purpose of this study was to evaluate the presence of dentinal defects after root canal preparation with hand instruments and two different reciprocating instruments. Sixty freshly extracted mandibular incisor teeth were selected for this in vitro study. On the basis of root length, mesiodistal and buccolingual dimensions, the teeth were allocated into three identical experimental groups (n = 15) and one control group (n = 15). The teeth in the control group were left unprepared. The other groups were: stainless steel hand instruments, WaveOne® Primary instruments and RECIPROC® R25 instruments. The reciprocating instruments were used with a reciprocating gentle in-and-out motion in a torque-limited electric motor at the appropriate preset mode. Horizontal sections were made 3, 6 and 9 mm from the apex. Samples were stained with methylene blue and viewed through a stereomicroscope. The presence of dentinal defects (fractures, incomplete cracks and craze lines) and their locations were investigated by two endodontists. These data were analysed statistically by Fisher's exact and chi-square tests. No defects were observed in the unprepared group. All instruments caused dentinal defects, with no significant differences between the instrument systems. All experimental groups demonstrated significantly more defects at the 3-mm level in comparison with the unprepared group (p = 0.032). At the other levels, there was no significant difference between the experimental groups and the control group. The use of hand or reciprocating instruments could induce the formation of dentinal defects during root canal preparation. PMID:26019654

  5. Effect of root canal sealer and artificial accelerated aging on fibreglass post bond strength to intraradicular dentin

    PubMed Central

    Santana, Fernanda-Ribeiro; Soares, Carlos-José; Ferreira, Josemar-Martins; Valdivi, Andréa-Dolores-Correia- Miranda; Souza, João-Batista-de

    2014-01-01

    Objectives: To evaluate the effect of root canal sealers (RCS) and specimen aging on the bond strength of fibre posts to bovine intraradicular dentin. Material and Methods: 80 teeth were used according the groups - Sealapextm, Sealer 26®, AH Plus® and specimens aging - test with no aging and with aging. The canals prepared were filled using one of each RCS. The posts were cemented. Roots were cross-sectioned to obtain two slices of each third. Samples were submitted to push-out test. Failure mode was evaluated under a confocal microscope. The data were analysed by ANOVA, Tukey’s, and Dunnet tests (α = 0.05). Results: No significant difference was detected among RCS. Aged control presented higher bond strength than immediate control. The aging did not result significant difference. Adhesive cement-dentin failure was prevalent in all groups. Conclusions: RCS interfered negatively with bonding of fibreglass posts cemented with self-adhesive resin cement to intraradicular dentin. Key words:Fibreglass post, bond strength, root dentin, endodontic sealer, aging. PMID:25593655

  6. The comparison of the effect of endodontic irrigation on cell adherence to root canal dentin.

    PubMed

    Ring, Karla C; Murray, Peter E; Namerow, Kenneth N; Kuttler, Sergio; Garcia-Godoy, Franklin

    2008-12-01

    The purpose of this study was to compare the effect of 10 different endodontic irrigation and chelating treatments on dental pulp stem cell (DPSC) attachment to root canal surfaces. Thirty-eight extracted human nondiseased single-canal teeth were cleaned and shaped using ProTaper and ProFile rotary instrumentation (Tulsa Dentsply, Tulsa, OK). The irrigation treatments investigated were 6% sodium hypochlorite, 2% chlorhexidine gluconate, Aquatine Endodontic Cleanser, and Morinda citrifolia juice. The irrigation treatments were used in conjunction with EDTA or MTAD. The instrumented teeth were immediately placed in cell culture with confluent DPSCs for 1 week. The number of attached DPSCs appeared to be correlated with the cytotoxicity of the root canal irrigating solution (analysis of variance, p < 0.0001). The presence or absence of the smear layer had little influence on DPSC activity (chi-square, p > 0.05). The results suggest that biocompatible irrigants are needed to promote DPSC attachment to root canal dentin, which is essential to accomplish some regenerative endodontic therapies. PMID:19026877

  7. NSK reciprocating handpiece: in vitro comparative analysis of dentinal removal during root canal preparation by different operators.

    PubMed

    Wagner, Márcia Helena; Barletta, Fernando Branco; Reis, Magda de Souza; Mello, Luciano Loureiro; Ferreira, Ronise; Fernandes, Antônio Luiz Rocha

    2006-01-01

    The purpose of this study was to assess dentin removal during root canal preparation by different operators using a NSK reciprocating handpiece. Eighty-four human single-rooted mandibular premolars were hand instrumented using Triple-Flex stainless-steel files (Kerr) up to #30, weighed in analytical balance and randomly assigned to 4 groups (n=21). All specimens were mechanically prepared at the working length with #35 to #45 Triple-Flex files (Kerr) coupled to a NSK (TEP-E10R, Nakanishi Inc.) reciprocating handpiece powered by an electric motor (Endo Plus; VK Driller). Groups 1 to 4 were prepared by a professor of Endodontics, an endodontist, a third-year dental student and a general dentist, respectively. Teeth were reweighed after root canal preparation. The difference between weights was calculated and the means of dentin removal in each group were analyzed statistically by ANOVA and Tukey's test at 5 % significance level. The greatest amount of dentin removal was found in group 4, followed by groups 2, 3 and 1. Group 4 differed statistically from the other groups regarding dentin removal means [p<0.001 (group 1); p=0.005 (group 2); and p=0.001 (group 3)]. No statistically significant difference was found between groups 1 and 2 (p=0.608), 1 and 3 (p=0.914) and 2 and 3 (p=0.938). In conclusion, although the group prepared by a general dentist differed statistically from the other groups in terms of amount of dentin removal, this difference was clinically irrelevant. The NSK reciprocating handpiece powered by an electric engine was proved an effective auxiliary tool in root canal preparation, regardless of the operator's skills. PMID:16721457

  8. Effect of gutta-percha solvents at different temperatures on the calcium, phosphorus and magnesium levels of human root dentin.

    PubMed

    Doğan, H; Taşman, F; Cehreli, Z C

    2001-08-01

    The aim of this study in vitro investigation was to evaluate the alterations caused by warmed gutta-percha solvents on the calcium, phosphorus and magnesium levels of root dentin. Extracted human anterior teeth, whose crowns and apical root thirds had been removed were used as root dentin specimens. The roots were sectioned longitudinally into two segments, cleaned and dried. Segments were divided into 12 groups (n=12). In 6 groups, the specimens received treatment with the following solvents at room temperature (22 degrees C): Chloroform, xylene, eucalyptol, orange oil, halothane and saline (control). Within each group, the specimens were further subgrouped into two to be incubated (100% humidity at 37 degrees C) for 5 and 10 min, respectively, following treatment with the solvents. The remaining six groups were treated with the same solvents which had been previously warmed to body temperature (37 degrees C) and received the same experimental procedures. The levels of calcium, phosphorus and magnesium in each specimen were analysed using energy dispersive spectrometric microanalysis. Statistical analysis of the readings showed that neither warming of the solvents nor prolonged incubation (treatment) time was capable of altering the histochemical composition of cut root dentin surfaces. PMID:11556962

  9. Tensile Bond Strengths of Two Adhesives on Irradiated and Nonirradiated Human Dentin.

    PubMed

    Bernard, Cécile; Villat, Cyril; Abouelleil, Hazem; Gustin, Marie-Paule; Grosgogeat, Brigitte

    2015-01-01

    The aim of this study was to assess the effect of radiotherapy on bond efficiency of two different adhesive systems using tensile bond strength test. Twenty extracted teeth after radiotherapy and twenty nonirradiated extracted teeth were used. The irradiation was applied in vivo to a minimal dose of 50 Gy. The specimens of each group were randomly assigned to two subgroups to test two different adhesive systems. A three-step/etch-and-rinse adhesive system (Optibond FL) and a two-steps/self-etch adhesive system (Optibond XTR) were used. Composite buildups were performed with a nanohybrid composite (Herculite XTR). All specimens were submitted to thermocycling ageing (10000 cycles). The specimens were sectioned in 1 mm(2) sticks. Microtensile bond strength tests were measured. Nonparametric statistical analyses were performed due to nonnormality of data. Optibond XTR on irradiated and nonirradiated teeth did not show any significant differences. However, Optibond FL bond strength was more effective on nonirradiated teeth than on irradiated teeth. Within the limitations of an in vitro study, it can be concluded that radiotherapy had a significant detrimental effect on bond strength to human dentin. However, it seems that adhesive choice could be adapted to the substrata. According to the present study, the two-steps/self-etch (Optibond XTR) adhesive system tested could be more effective on irradiated dentin compared to three-steps/etch-and-rinse adhesive system (Optibond FL). PMID:26783528

  10. Tensile Bond Strengths of Two Adhesives on Irradiated and Nonirradiated Human Dentin

    PubMed Central

    Bernard, Cécile; Abouelleil, Hazem; Gustin, Marie-Paule; Grosgogeat, Brigitte

    2015-01-01

    The aim of this study was to assess the effect of radiotherapy on bond efficiency of two different adhesive systems using tensile bond strength test. Twenty extracted teeth after radiotherapy and twenty nonirradiated extracted teeth were used. The irradiation was applied in vivo to a minimal dose of 50 Gy. The specimens of each group were randomly assigned to two subgroups to test two different adhesive systems. A three-step/etch-and-rinse adhesive system (Optibond FL) and a two-steps/self-etch adhesive system (Optibond XTR) were used. Composite buildups were performed with a nanohybrid composite (Herculite XTR). All specimens were submitted to thermocycling ageing (10000 cycles). The specimens were sectioned in 1 mm2 sticks. Microtensile bond strength tests were measured. Nonparametric statistical analyses were performed due to nonnormality of data. Optibond XTR on irradiated and nonirradiated teeth did not show any significant differences. However, Optibond FL bond strength was more effective on nonirradiated teeth than on irradiated teeth. Within the limitations of an in vitro study, it can be concluded that radiotherapy had a significant detrimental effect on bond strength to human dentin. However, it seems that adhesive choice could be adapted to the substrata. According to the present study, the two-steps/self-etch (Optibond XTR) adhesive system tested could be more effective on irradiated dentin compared to three-steps/etch-and-rinse adhesive system (Optibond FL). PMID:26783528

  11. Effect of root canal rinsing protocol on dentin bond strength of two resin cements using three different method of test

    PubMed Central

    Khoroushi, Maryam; Sheikhi, Mohammadreza; Soleimani, Bahram

    2016-01-01

    Background Different studies have used different tests to evaluate bond strength of resin cements to root dentin. In this in vitrostudy, three different tests were used to evaluate the bond strength of two resin cements to root dentin using two root dentin irrigation protocols. Material and Methods Ninety-six intact single-rooted teeth were selected for this study. Forty-eight teeth, with a root length of 15mm, were randomly divided into two groups and irrigated with normal saline or 2.5% sodium hypochlorite solutions during root canal preparation, respectively. For each 12 specimens from each group, fiber post #1 was bonded using an etch-and-rinse (Duo-Link) and a self-adhesive (BisCem) resin cement, respectively. After incubation, two specimens were prepared for the push-out test from the middle thirds of the roots. In another 24 teeth, after two 1.5-mm sections were prepared from the middle thirds of the prepared roots, sections of the post were bonded in two subgroups with each of the cements mentioned above and the samples were prepared for the pull-out test. For shear test, the crowns of 48 teeth were cut away, the dentin surfaces were prepared, the two irrigation solutions were used, and the resin cements were bonded. Data collected from the three tests were evaluated by ANOVA, post-hoc Tukey and Weibull tests (α=0.05). Results There were significant differences in the mean bond strength values between the three bond strength tests (P<0.001). Rinsing protocol and cement type resulted in similar variations in the mean bond strength in all tests (P>0.05). Conclusions Under the limitations of the present study, the method of the test used had an effect on the recorded bond strength between the resin cement and root dentin. Cement type and irrigation protocol resulted in similar variations with all the tests. Push-out and shear tests exhibited more coherent results. Key words:Bond strength, endodontically treated tooth, fiber post, resin cement, sodium

  12. Age-related ransparent root dentin: mineral concentration,crystallite size and mechanical properties

    SciTech Connect

    Kinney, John H.; Nalla, Ravi K.; Pople, John A.; Breunig, Tom M.; Ritchie, Robert O.

    2004-12-29

    Many fractures occur in teeth that have been altered, forexample restored or endodontically repaired. It is therefore essential toevaluate the structure and mechanical properties of these altereddentins. One such altered form of dentin is transparent (sometimes calledsclerotic) dentin, which forms gradually with aging. The present studyfocuses on differences in the structure and mechanical properties ofnormal versus transparent dentin. The mineral concentration, as measuredby X-ray computed microtomography, was signifcantly higher in transparentdentin, the elevated concentration being consistent with the closure ofthe tubule lumens. Crystallite size, as measured by small angle X-rayscattering, was slightly smaller in transparent dentin, although theimportance of this ending requires further study. The elastic propertieswere unchanged by transparency; however, transparent dentin, unlikenormal dentin, exhibited almost no yielding before failure. In addition,the fracture toughness was lowered by roughly 20 percent while thefatigue lifetime was deleteriously affected at high stress levels. Theseresults are discussed in terms of the altered microstructure oftransparent dentin.

  13. Assessment of Photodynamic Therapy (PDT) in Disinfection of Deeper Dentinal Tubules in a Root Canal System: An In Vitro Study

    PubMed Central

    Bhaskar, Dara John; Agali, Chandan R; Punia, Himanshu; Gupta, Vipul; Singh, Vikas; Kadtane, Safalya; Chandra, Sneha

    2014-01-01

    Context: The success of endodontic treatment therapy depends on how well we eliminate pathogenic microflora from the root canal system as micro organism as the major cause of root canal infection. Conventional root canal treatment can fail if microorganisms cannot be removed sufficiently by thorough cleaning, shaping of root canal. Newer modalities such as photodynamic therapy are being tried now a days for disinfection of root canals. Aim & Objectives: The basic aim of this study was assessment of the antimicrobial efficacy of Photodynamic Therapy in deeper dentinal tubules for effective disinfection of root canals using microbiological and scanning electron microscopic examination in vitro. Materials and Methods: The study was conducted at Teerthanker Mahaveer Dental College & Research Centre. The teeth required for study was collected from Department of Oral and Maxillofacial Surgery. Only freshly extracted 20 intact, non carious single rooted teeth which were indicated for orthodontic treatment were taken for this study. Statistical analysis was done using Student’s Unpaired t-test were at (p<0.001) was found to be highly significant. Microbiological examination of samples were done and colony forming units were counted to assess the disinfection potential of photodynamic therapy. Scanning electron microscopic examination of samples was done to check penetration of bacteria’s into deeper dentinal tubules. Results: On examination, there was a marked reduction in microbial growth after use of photodynamic therapy. On scanning electron microscopic examination, it was observed that there were less number of bacteria’s in deeper dentinal tubules in case of PDT group as compared to control group. Conclusion: The results of the present study indicate that PDT can be effectively used during antimicrobial procedures along with conventional disinfection procedure for sterilization of root canals. PMID:25584321

  14. Calcium loss from root canal dentin following EDTA and Tetracycline HCl Treatment with or without subsequent NaOCl irrigation and evaluation of microhardness of dentine

    NASA Astrophysics Data System (ADS)

    Mishra, Lora; Kumar, Manoj; Rao, C. V. Subba

    2012-07-01

    To assess Calcium loss from root canal dentin following EDTA and Tetracycline ñ HCL Treatment with or without subsequent NaOCl Irrigation and evaluation of microhardness of dentin. Materials and methods: Sixty freshly extracted single rooted premolars were selected.The teeth were sectioned l ongitudinally into two equal halves along the long axis using Diamond di sc. The one half of the specimen is used for the Calcium l oss eva luation by ICP-AES technique and the other one half with the acrylic block i s used for the micro hardness study. The data was analysed using One ñ way ANOVA and Post Hoc Tuckey test. Results: The maximum calcium loss was observed in Group V 17% EDTA +2.5% NaOCl (3.88 ± 0.30), followed by Group III 17% EDTA (3.46 ± 0.43 mg/L), Group VI 1% Tetracycline HCl + 2.5% NaOCl (1.71 ±0.28mg/L), Group IV Tetracycline HCl (1.46 ± 0.29mg/L). Group I distilled water (0.17± 0.25mg/L) and Group II 2.5% NaOCl (0.28± 0.05mg/L) had the least calcium loss value with p < 0.001. Dentin Microhardness i n Group I (67.6 ± 1.70 VHN), Group II (65.5 ± 3.57 VHN) Group IV and in Group VI ( 61.5± 1.09) showed significantly higher when compared to the mean values in Group III (59.7 ± 4.3 mg/L) and in Group V =(55.2±2.53VHN) withp<0.001. Conclusion: Group V 17% EDTA + 2.5% NaOCl resulted in maximum Calcium loss, but has reduced the microhardness. But Group VI 1%Tetracycline H Cl + 2.5% NaOCl solution e ffectively removed Calcium without much altering the microhardness of the r oot dentin .

  15. The effect of nonsetting calcium hydroxide on root fracture and mechanical properties of radicular dentine: a systematic review.

    PubMed

    Yassen, G H; Platt, J A

    2013-02-01

    The aim of this review was to identify and analyse all studies related to the effect of nonsetting calcium hydroxide [Ca(OH)(2)] on root fracture and various mechanical properties of radicular dentine. A PubMed search was conducted using the keywords 'calcium hydroxide' and 'dentistry' combined with MeSH terms 'tooth fractures' or 'mechanical phenomena' or 'compressive strength'. The search was expanded by including Embase and Web of Science databases, using the keywords 'calcium hydroxide' and 'root' and 'fracture'. The search was supplemented by checking the reference lists from each selected article. Each study had to meet the following criteria to be selected for review: (i) Inclusion of at least one experimental group with root or radicular dentine either filled with or exposed to nonsetting Ca(OH)(2); (ii) inclusion of at least one appropriate control group; and (iii) a minimum of five samples per experimental group. Only articles written in English were included. Of the 16 studies selected initially, 12 in vitro studies fulfilled the selection criteria for inclusion in the final review. No clinical studies that directly supported the correlation between Ca(OH)(2) intracanal dressing and root fracture were found in the literature. However, the majority of in vitro studies showed reduction in the mechanical properties of radicular dentine after exposure to Ca(OH)(2) for 5 weeks or longer. Conversely, the data were inconclusive regarding whether Ca(OH)(2) exposure for 1 month or less had a negative effect on the mechanical properties of radicular dentine. PMID:22970899

  16. Temperature rise after KTP:NdYAG laser irradiation as a root-planing complement

    NASA Astrophysics Data System (ADS)

    Nammour, S.; Kowalyk, Kenneth; Valici, Ch.; Guillaume, Patrick

    1997-05-01

    The purposes of this study was to define the optimal irradiation conditions of a KTP:NdYAG laser after root planning treatment. The surfaces of 40 single-root human teeth were scaled with conventional tools before lasing. The pulpal temperature increase was measured by means of a thermocouple. The influence of variables of coloration by Acid Red 52, scanning speed, dentin thickness, and probe position, have been analyzed for a constant exposure time of 15 seconds. The temperature was below 3 C for the adjustments, power output: 400 mw, scanning speed of irradiation: 2 mm/sec., and Pw 0.10 m sec, PRR < 60 Hz or Pw: 0.12 m sec, PRR < 55 Hz.

  17. Spectroscopic alterations on enamel and dentin after nanosecond Nd:YAG laser irradiation

    NASA Astrophysics Data System (ADS)

    Antunes, A.; de Rossi, W.; Zezell, D. M.

    2006-08-01

    Laser irradiation on hard tissue has produced a resistant surface that is likely to prevent caries. In this study, human enamel and dentine were exposed to nanosecond pulsed Nd:YAG laser with energy densities of 20-40 J/cm 2 and pulse width of 6 ns inducing chemical changes in these tissues. Infrared analysis of human dental enamel and dentine was performed using the KBr method (2 mg sample/300 mg KBr). A correlation between non-lased and lased spectra was performed that gives an indication of the changes in organic and inorganic compounds after laser-tissue interaction. Spectra of teeth simultaneously show the inorganic and organic parts of the tissue. The principal bands: amide bands A, I, II, and III from the collagen-matrix, phosphate from the mineral content, and carbonate bands were identified. The normalized area of peak versus peak position was determined. Changes of the bands attributed to the collagen matrix were verified after Nd:YAG irradiation. The present results suggest a chemical modification of organic and mineral compounds by laser. The spectral results indicated an alteration in the absorption bands relative to, essentially, organic compounds.

  18. Root dentine transparency: age determination of human teeth using computerized densitometric analysis.

    PubMed

    Drusini, A; Calliari, I; Volpe, A

    1991-05-01

    Root dentine transparency (RDT) was used to estimate the ages of human subjects from 152 intact teeth. Teeth were from 134 subjects, both historical and recent, of known age and sex. The aims of this work are 1) to compare two methods of using RDT to estimate age; 2) to test the applicability of the regression formulae for estimating age obtained from a recent sample on an historical sample; and 3) to estimate the suitability of RDT to determine age at death of 100-year-old skeletons. RDT was measured by two techniques: 1) computerized densitometric analysis and 2) vernier caliper. Age estimations based on computerized densitometric analysis were no more accurate than were those determined by caliper measurement; both give a predictive success of +/- 5 years in about 45-48% of cases for premolars. The television-based digitization system has some disadvantages: It is expensive, not portable, and requires some training to use. However, it furnishes a more standardized method, a rapid graphic illustration of the results, and an immediate storage of statistical information for future use. PMID:1853940

  19. The effect of a desensitizer and CO2 laser irradiation on bond performance between eroded dentin and resin composite

    PubMed Central

    Ding, Meng; Shin, Sang-Wan; Kim, Min-Soo

    2014-01-01

    PURPOSE This study was aimed to evaluate effect of the desensitizing pretreatments on the micro-tensile bond strengths (µTBS) to eroded dentin and sound dentin. MATERIALS AND METHODS Forty-two extracted molars were prepared to form a flat dentin surface, and then they were divided into two groups. Group I was stored in distilled water while group II was subjected to a pH cycling. Each group was then subdivided into three subgroups according to desensitizing pretreatment used: a) pretreatment with desensitizer (Gluma); b) pretreatment with CO2 Laser (Ultra Dream Pluse); c) without any pretreatment. All prepared surfaces were bonded with Single Bond 2 and built up with resin composite (Filtek Z250). The micro-tensile bond test was performed. Fracture modes were evaluated by stereomicroscopy. Pretreated surfaces and bonded interfaces were characterized by scanning electron microscope (SEM). The data obtained was analyzed by two-way ANOVA (α=0.05). RESULTS For both sound and eroded dentin, samples treated with desensitizer showed the greatest µTBS, followed by samples without any treatment. And samples treated with CO2 laser showed the lowest µTBS. SEM study indicated that teeth with eroded dentin appeared prone to debonding, as demonstrated by existence of large gaps between adhesive layers and dentin. CONCLUSION Pretreatment with Gluma increased the µTBS of Single Bond 2 for eroded and sound teeth. CO2 laser irradiation weakened bond performance for sound teeth but had no effect on eroded teeth. PMID:25006379

  20. Bond strength of composite to dentin: effect of acid etching and laser irradiation through an uncured self-etch adhesive system

    NASA Astrophysics Data System (ADS)

    Castro, F. L. A.; Carvalho, J. G.; Andrade, M. F.; Saad, J. R. C.; Hebling, J.; Lizarelli, R. F. Z.

    2014-08-01

    This study evaluated the effect on micro-tensile bond strength (µ-TBS) of laser irradiation of etched/unetched dentin through an uncured self-etching adhesive. Dentinal surfaces were treated with Clearfil SE Bond Adhesive (CSE) either according to the manufacturer’s instructions (CSE) or without applying the primer (CSE/NP). The dentin was irradiated through the uncured adhesive, using an Nd:YAG laser at 0.75 or 1 W power settings. The adhesive was cured, composite crowns were built up, and the teeth were sectioned into beams (0.49 mm2) to be stressed under tension. Data were analyzed using one-way ANOVA and Tukey statistics (α = 5%). Dentin of the fractured specimens and the interfaces of untested beams were observed under scanning electron microscopy (SEM). The results showed that non-etched irradiated surfaces presented higher µ-TBS than etched and irradiated surfaces (p < 0.05). Laser irradiation alone did not lead to differences in µ-TBS (p > 0.05). SEM showed solidification globules on the surfaces of the specimens. The interfaces were similar on irradiated and non-irradiated surfaces. Laser irradiation of dentin through the uncured adhesive did not lead to higher µ-TBS when compared to the suggested manufacturer’s technique. However, this treatment brought benefits when performed on unetched dentin, since bond strengths were higher when compared to etched dentin.

  1. Application of a proanthocyanidin agent to improve the bond strength of root dentin treated with sodium hypochlorite

    PubMed Central

    Manimaran, V Sujatha; Srinivasulu, Sakhamuri; Rajesh Ebenezar, AV; Mahalaxmi, S; Srinivasan, N

    2011-01-01

    Aim: The objective of this study was to analyze the application of PA agent that improves the bond strength of root dentin treated with NaOCl. Materials and Methods: Group 1: root canals were irrigated using 0.9% isotonic saline as an irrigant (negative control); Group 2: root canals were irrigated using 5.25% NaOCl (positive control); Group 3: root canals were irrigated with 5.25% NaOCl followed by 10% sodium ascorbate for 10 minutes; Group 4: root canals were irrigated with 5.25% NaOCl followed by 5% PA for 10 minutes. All the canals were then coated with self-etch dentin bonding agent, filled with resin cement, stored for one day in water, and then cross sectioned into three slabs of 2-mm thickness that were prepared and tested for microtensile bond strength. Results: The results demonstrated that 5.25% NaOCl caused significant reduction (P<0.05) in the bond strength, but this can be reversed by 5% PA significantly more than the 10% sodium ascorbate. PMID:22025839

  2. Effect of irrigation technique for removal of triple antibiotic paste on bond strength of MTA to root dentin.

    PubMed

    Dumani, Aysin; Yilmaz, Sehnaz; Yoldas, Oguz; Bek, Zeliha Gonca

    2016-01-01

    This study evaluated the bond strength of mineral trioxide aggregate (MTA) to root canal dentin after the performance of various irrigation procedures to remove triple antibiotic paste (TAP). A total of 56 single-rooted human mandibular premolars were instrumented using a rotary system to size 40 and divided randomly into a control group (no intracanal dressing) and three experimental groups (TAP application for 28 days). TAP was then removed by rinsing with 10 mL 2.5% NaOCl using three irrigation systems (Vibringe sonic irrigation, CanalBrush, and syringe irrigation). The coronal and middle parts of root canals were then obturated with MTA. After storage for 1 week, each specimen was embedded in an acrylic block and sectioned horizontally (2-mm-thick slices) at two levels (coronal and middle). Bond strength of MTA to root canal dentin was assessed in 28 samples per group via push-out test using a universal testing machine. Data from the four groups were compared using one-way analysis of variance. Tukey's test was used for multiple comparisons. Push-out bond strength values were significantly higher in the control and Vibringe groups than in the CanalBrush and syringe irrigation groups (p < 0.001). TAP removal from root canals with the Vibringe irrigation system may increase the push-out bond strength of MTA compared with the use of the CanalBrush or syringe irrigation. PMID:27191739

  3. Scanning electron microscopy study of the adhesion of Prevotella nigrescens to the dentin of prepared root canals.

    PubMed

    Yang, Sung-Eun; Bae, Kwang-Shik

    2002-06-01

    The purpose of this study was to evaluate the effect of the presence or absence of amorphous, irregular smear layers on the adhesion of Prevotella nigrescens, to the dentin of the root canal by using scanning electron microscopy (SEM). Human incisors extracted within 7 days, with no cavities, no fractures, and no evidence of calcification of the canal, were selected. After cutting the crown portion at the CEJ, root canal preparation was undertaken by using a modified crown-down technique with Profile and Gates Glidden drills. Ten milliliters of physiologic saline solution (groups 1 and 4), 10 ml of 3.5% NaOCl (groups 2 and 5), or 10 ml of NaOCl and 10 ml of 0.5 M EDTA (groups 3 and 6) were used as irrigation solution while preparing the canal. After vertical sectioning and ethylene oxide gas sterilization, samples (groups 1, 2, and 3) were immersed in brain-heart infusion broth with yeast extract, hemin, and menadione, inoculated with P. nigrescens (ATCC 33563), and incubated for 3 h at 37 degrees C. All samples were prepared for and observed with SEM. The data were analyzed by using t test and one-way ANOVA. Smear layer was observed to cover the entire root canal surface after root canal preparation. Smear layer was removed and the entrances of dentinal tubules opened widely after applying 3.5% NaOCl and 0.5 M EDTA. A significantly greater number of bacteria were found to adhere to those teeth in which a smear layer was present (p < 0.05). Given that the smear layer produced during root canal preparation promoted adhesion and colonization of P. nigrescens to the dentin matrix, it might also increase the likelihood of canal reinfection. PMID:12067123

  4. Effects of Er:YAG laser irradiation and manipulation treatments on dentin components, part 1: Fourier transform-Raman study

    NASA Astrophysics Data System (ADS)

    Soares, Luís Eduardo Silva; Do Espírito Santo, Ana Maria; Junior, Aldo Brugnera; Zanin, Fátima Antônia Aparecida; da Silva Carvalho, Carolina; de Oliveira, Rodrigo; Martin, Airton Abraha~O.

    2009-03-01

    The effects of laser etching, decontamination, and storage treatments on dentin components were studied using Fourier transform (FT)-Raman spectroscopy. Thirty bovine incisors were prepared to expose the dentin surface and then divided in two main groups based upon the decontamination process and storage procedure: autoclaved (group A, n=15) or stored in thymol aqueous solution (group B, n=15). The surfaces of the dentin slices were schematically divided into four areas, with each one corresponding to a treatment subgroup. The specimens were either etched with phosphoric acid (control subgroup) or irradiated with erbium-doped yttrium-aluminum-garnet (Er:YAG) laser (subgroups: I-80 mJ, II-120 mJ, and III-180 mJ, and total energy of 12 J). Samples were analyzed by FT-Raman spectroscopy; we collected three spectra for each area (before and after treatment). The integrated areas of five Raman peaks were calculated to yield average spectra. The areas of the peaks associated with phosphate content (P<0.001), type I collagen, and organic C-H bonds (P<0.05) were reduced significantly in group A (control). Analyses of samples irradiated with reduced laser energies did not show significant changes in the dentin components. These results suggest that thymol storage treatment is advised for in vitro study; furthermore, 12 J of Er:YAG laser energy does not affect dentin components.

  5. The efficacy of an experimental single solution versus alternate use of multiple irrigants on root dentin microhardness

    PubMed Central

    Erdilek, Necdet; Sen, Bilge H.

    2013-01-01

    Objectives: This study was carried-out to evaluate and compare the efficacy of various irrigants when used singly or in combination on the microhardness of root canal dentin. Study Design: A total of 50 root-halves were randomly divided into 5 groups immediately after the initial baseline microhardness measurements and treated with: Group-1; 7.5%Ethylenediaminetetraaceticacid (EDTA) + 2.5%sodium hypochlorite (NaOCl), Group-2; 7.5%ethyleneglycol-bis[b-aminoethylether]-N,N,N0,N0-tetraaceticacid (EGTA) + 2.5%NaOCl, Group-3; 7.5%trans1,2diaminocyclohexane NNN’,N’tetraaceticacid (CDTA) + 2.5% NaOCl, Group-4; 7.5%EDTA + 2.5% Ethylenediamine (EDA), and Group-5; 1/1 (v/v) EDTA-EDA mixture + 1/1 (v/v) EDTA-EDA mixture. Fifty mL of each solution was used for 1 minute. The reference and post-treatment microhardness values were measured with a Vickers indenter under 80-gram load, 15-second dwell time. Data were analyzed by two-way ANOVA and Bonferroni tests (p=0.05). Results: All solutions decreased microhardness of dentin (p< 0.05). There was statistically significant difference between each group, except Group-1 and 4, after 1st solution application. While Group-2 resulted in a greater reduction of dentin hardness, Group-5 caused the least change in microhardness values, after 1st solution application (p< 0.05). No statistical difference was observed between Groups 1-4, after 2nd solution application. However, Group-5 showed a significant difference compared with all other groups, after 2nd solution application (p< 0.05). Conclusions: Under the experimental conditions, all tested solutions reduced the microhardness of the root canal dentin. EGTA was the most efficient chelating agent. EDTA-EDA single mixture has led to least change on the microhardness of root dentin. Key words:Microhardness, CDTA, EDTA, EGTA, Ethylenediamine. PMID:24455062

  6. Pulp-dentine complex changes and root resorption during intrusive orthodontic tooth movement in patients prescribed nabumetone.

    PubMed

    Villa, Paula A; Oberti, Giovanni; Moncada, Cesar A; Vasseur, Olga; Jaramillo, Alejandro; Tobón, Diego; Agudelo, Jaime A

    2005-01-01

    Pulpitis, external root resorption, and pain may be experienced during orthodontic movement. The use of nonsteroidal anti-inflammatory drugs (NSAIDs) has been suggested to control these changes. The purpose of this study was to observe pulp-dentinal reactions, root resorption, tooth pain, and tooth movement after the application of a 4-ounce intrusive orthodontic force to human maxillary first premolars in patients given the NSAID nabumetone. Thirty-four maxillary first premolars were evaluated. A placebo was prescribed to 17 patients after an intrusive force was activated and reactivated for an 8-week period on the right side. The same procedure was repeated on the left side after patients were given nabumetone. Pulp-dentinal reactions and external root resorption were evaluated by histology. Pain and movement were also evaluated. Nabumetone was found to be useful in reducing pulpitis, external root resorption, and pain caused by intrusive orthodontic movement, without altering tooth movement in response to the application of orthodontic force. PMID:15614010

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

    NASA Astrophysics Data System (ADS)

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

    2010-11-01

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

  8. Push-out bond strength of fiber posts to root dentin using glass ionomer and resin modified glass ionomer cements

    PubMed Central

    PEREIRA, Jefferson Ricardo; da ROSA, Ricardo Abreu; SÓ, Marcus Vinícius Reis; AFONSO, Daniele; KUGA, Milton Carlos; HONÓRIO, Heitor Marques; do VALLE, Accácio Lins; VIDOTTI, Hugo Alberto

    2014-01-01

    Objective The purpose of this study was to assess the push-out bond strength of glass fiber posts to root dentin after cementation with glass ionomer (GICs) and resin-modified glass ionomer cements (RMGICs). Material and Methods Fifty human maxillary canines were transversally sectioned at 15 mm from the apex. Canals were prepared with a step back technique until the application of a #55 K-file and filled. Post spaces were prepared and specimens were divided into five groups according to the cement used for post cementation: Luting & Lining Cement; Fuji II LC Improved; RelyX Luting; Ketac Cem; and Ionoseal. After cementation of the glass fiber posts, all roots were stored at 100% humidity until testing. For push-out test, 1-mm thick slices were produced. The push-out test was performed in a universal testing machine at a crosshead speed of 0.5 mm/minute and the values (MPa) were analyzed by Kolmogorov-Smirnov and Levene's tests and by two-way ANOVA and Tukey's post hoc test at a significance level of 5%. Results Fiber posts cemented using Luting & Lining Cement, Fuji II LC Improved, and Ketac Cem presented the highest bond strength to root dentin, followed by RelyX Luting. Ionoseal presented the lowest bond strength values (P>0.05). The post level did not influence the bond strength of fiber posts to root dentin (P=0.148). The major cause of failure was cohesive at the cement for all GICs and RMGICs. Conclusions Except for Ionoseal, all cements provided satisfactory bond strength values. PMID:25004052

  9. Effect of the Type of Endodontic Sealer on the Bond Strength Between Fiber Post and Root Wall Dentin

    PubMed Central

    Mosharraf, Ramin; Zare, Sepideh

    2014-01-01

    Objectives: An important factor that interferes with the bonding between the root canal wall and resin cement is the root canal sealer remnant. There is controversy about the effect of eugenol-containing sealers on the bond strength between resin cements and fiber post. The aim of this study was to evaluate the effect of the type of endodontic sealer on the bond strength of FRC posts cemented with resin cement to the root canal wall. Materials and Methods: In this in vitro study, 20 extracted mandibular first premolars were endodontically treated and divided into two groups according to the endodontic sealer used (n=10): G1: AH26 (Resin based); and G2: Endofill (Eugenol-based). After preparing post space, adhesive resin cement (Panavia F 2.0) was used for cementation of the fiber post to the root canal dentin. Three 3 mm thick slices were obtained from each root. The push-out test was performed with a cross-head speed of 1 mm/minute. Two-way ANOVA and Tukey post hoc tests were used for analyzing data (α=0.05). Results: The two-way ANOVA showed that different root canal sealers (P=0.037) had significant effects on bond strength (BS), but root canal regions (P=0.811) and interaction between root canal sealers and root canal regions (P=0.258) had no significant effects on BS. Maximum and minimum mean values were observed in the AH26 group, the apical region and the Endofill group in the apical region, respectively. Post Hoc Tukey test revealed that there were no significant differences between different root canal regions in both cements (P>0.05). Conclusion: The region of root canal had no effect on the bond strength of cemented fiber posts to the root canal. Eugenol-based sealers (Endofill) significantly reduced the bond strength between fiber posts luted with resin cement to the root canal. PMID:25584058

  10. Push-out bond strength and dentinal tubule penetration of different root canal sealers used with coated core materials

    PubMed Central

    Purali, Nuhan; Coşgun, Erdal; Calt, Semra

    2016-01-01

    Objectives The aim of this study was to compare the push-out bond strength and dentinal tubule penetration of root canal sealers used with coated core materials and conventional gutta-percha. Materials and Methods A total of 72 single-rooted human mandibular incisors were instrumented with NiTi rotary files with irrigation of 2.5% NaOCl. The smear layer was removed with 17% ethylenediaminetetraacetic acid (EDTA). Specimens were assigned into four groups according to the obturation system: Group 1, EndoRez (Ultradent Product Inc.); Group 2, Activ GP (Brasseler); Group 3, SmartSeal (DFRP Ltd. Villa Farm); Group 4, AH 26 (Dentsply de Trey)/gutta-percha (GP). For push-out bond strength measurement, two horizontal slices were obtained from each specimen (n = 20). To compare dentinal tubule penetration, remaining 32 roots assigned to 4 groups as above were obturated with 0.1% Rhodamine B labeled sealers. One horizontal slice was obtained from the middle third of each specimen (n = 8) and scanned under confocal laser scanning electron microscope. Tubule penetration area, depth, and percentage were measured. Kruskall-Wallis test was used for statistical analysis. Results EndoRez showed significantly lower push-out bond strength than the others (p < 0.05). No significant difference was found amongst the groups in terms of percentage of sealer penetration. SmartSeal showed the least penetration than the others (p < 0.05). Conclusions The bond strength and sealer penetration of resin-and glass ionomer-based sealers used with coated core was not superior to resin-based sealer used with conventional GP. Dentinal tubule penetration has limited effect on bond strength. The use of conventional GP with sealer seems to be sufficient in terms of push-out bond strength. PMID:27200279

  11. The effect of three different antioxidants on the dentinal tubular penetration of Resilon and Real Seal SE on sodium hypochlorite-treated root canal dentin: An in vitro study

    PubMed Central

    Christopher, Sarah Renjelina; Mathai, Vijay; Nair, Rajesh Sasidharan; Angelo, Jeyabalaji Mano Christaine

    2016-01-01

    Objective: The effect of 10% ascorbic acid, 10% tannic acid, and 10% gallic acid on the dentinal tubular penetration of Resilon and Real Seal SE on sodium hypochlorite-treated root canal dentin was evaluated. Materials and Methods: Fifty human premolars were decoronated to attain 14-mm root length and divided into five groups of 10 teeth each. Biomechanical preparation was done with rotary instruments. Group I specimens were irrigated with saline and 17% ethylenediaminetetraacetic acid (EDTA). Specimens from groups II, III, IV, and V were irrigated with 5.25% sodium hypochlorite and 17% EDTA. Specimens from groups III, IV, and V underwent additional irrigation with antioxidants–10% ascorbic acid, 10% tannic acid, and 10% gallic acid, respectively. Following obturation with Resilon and Real Seal SE, scanning electron microscope (SEM) analysis was done to note the maximum dentinal tubular penetration at the cervical, middle, and apical thirds of each specimen. The data were statistically analyzed using one-way analysis of variance (ANOVA), Post hoc and Dunnett's test. Results: Maximum dentinal tubular penetration of Resilon and Real Seal SE was obtained following irrigation with 10% gallic acid. Conclusion: 10% gallic acid was superior among the antioxidant irrigants that enabled the increased dentinal tubular penetration of Resilon and Real Seal SE. PMID:27099424

  12. Effect of final irrigation protocols on push-out bond strength of an epoxy resin root canal sealer to dentin.

    PubMed

    Leal, Fernanda; Simão, Renata Antoun; Fidel, Sandra Rivera; Fidel, Rivail Antônio Sérgio; do Prado, Maíra

    2015-12-01

    The purpose of the present study was to evaluate the effect of different final irrigation protocols on push-out bond strength of an epoxy resin root canal sealer to dentin. Eighty single-rooted anterior teeth were used. The root canals were partially prepared using a rotary system and the final diameter was standardised using a #5 Gates-Glidden drill prior to the push-out bond test. During chemomechanical preparation, 5.25% NaOCl or 2% CHX gel was used. For smear layer removal, 17% ethylenediaminetetraacetic acid (EDTA) or QMix 2 in 1 was applied for 3 min. As final irrigant, 1 mL of NaOCl, CHX solution or distilled water was used. On conclusion of preparation, canals were filled with gutta-percha/AH Plus sealer. Bond strength was measured by the push-out test. Data were statistically analysed by Kruskal-Wallis and Mann-Whitney U-tests. The group NaOCl/EDTA/NaOCl showed significantly higher bond strength values than other groups. In all groups, there were mainly mixed failure patterns. It can be concluded that 5.25% NaOCl proved to be the best solution for the final irrigation when combined with EDTA. The final irrigation protocols affect the push-out bond strength of AH Plus to dentin. PMID:25950117

  13. Marginal adaptation of mineral trioxide aggregate (MTA) to root dentin surface with orthograde/retrograde application techniques: A microcomputed tomographic analysis

    PubMed Central

    Al Fouzan, Khalid; Awadh, Mohammed; Badwelan, Moahmmed; Gamal, Abeer; Geevarghese, Amrita; Babhair, Samar; Al-Rejaie, Mansour; Al Hezaimi, Khalid; Rotstein, Ilan

    2015-01-01

    Background: Achieving a good apical seal for root canals is known to be associated with good mineral trioxide aggregate (MTA) adaptation to dentin. Aims: This study aims to compare the marginal adaptation of MTA with root dentin between orthograde and retrograde application techniques using microcomputed tomography (micro-CT) analysis. Settings and Design: Fifty-two single-rooted human teeth were divided into four equal groups: (Group 1) Retrograde MTA (RMTA), (Group 2) Orthograde MTA (OMTA), (Group 3) Etched RMTA (ERMTA), and (Group 4) Etched OMTA (EOMTA). Materials and Methods: For Group 1, 3-mm retrograde cavities were prepared and filled with MTA. For Group 2, the apical 6 mm of the canals were filled with MTA and sealed with sealer cement and warm gutta-percha. In Groups 3 and 4, canals were treated the same as Groups 1 and 2, respectively, except that before placing the MTA, canals were irrigated with 17% ethylenediaminetetraacetic acid (EDTA). After 48 hours, all the teeth were analyzed using a micro-CT scanner. Statistical Analysis: Mean dentin-MTA contact and the mean length and width of each gap was analysed using one-way analysis of variance (ANOVA). Statistical significance was set at an α level of 5%. Results: No significant difference in gap volumes was observed in the dentin-MTA adaptation in both orthograde and retrograde application techniques. However, significant difference in the gap volumes was observed between RMTA and ERMTA (P = 0.045). Etching significantly improved the MTA-Dentin adaptation (P < 0.05). The type of application technique did not significantly improve the dentin-MTA adaptation, instead with the use of 17% EDTA, a significant improvement could be achieved. Conclusion: Within the limitations of the present study, it concludes that MTA adaptation to dentin tooth structure is not significantly different between an orthograde and retrograde approach. However, the use of EDTA significantly improved the MTA-Dentin adaptation. PMID

  14. Nd:YAG Laser Irradiation of the Tooth Root Surface Inhibits Demineralization and Root Surface Softening Caused by Minocycline Application

    PubMed Central

    Watanabe, Tomohisa; Mitani, Akio; Ting, Chun-Chan; Osawa, Kazuhiro; Nagahara, Ayako; Satoh, Sohta; Fujimura, Takeki; Takahashi, Shinko; Iwamura, Yuki; Murakami, Taeko; Noguchi, Toshihide

    2013-01-01

    Abstract Objective: The aim of this study was to investigate the effect of laser irradiation on root surface demineralization caused by local drug delivery systems (DDS), and to evaluate the effect of sealing on drug retention. Background data: The duration of supportive periodontal treatment (SPT) has increased with increasing life expectancy. Repeated root planing and DDS application during SPT should be reconsidered with regard to their effects on the root surface. Methods: Extracted human teeth were collected, cut into 3×3×2 mm root dentin specimens, and divided randomly into eight groups with various combinations of Nd:YAG laser power (0, 0.5, 1, and 2 W), with and without DDS (minocycline HCl). Specimen microhardness and calcium (Ca) solubility were measured after treatment. The specimens (control and laser and DDS groups) were examined by scanning electron microscopy. Forty SPT patients were recruited, to assess the effect of periodontal pocket sealing on drug retention. Results: Laser irradiation increased the microhardness of root specimens in an energy-dependent manner. Calcium solubilities decreased from the 0 W+DDS group to the 2.0 W+DDS group. The mean Ca solubilities in the 1.0 W+DDS and 2.0 W+DDS groups were significantly lower than in the 0 W+DDS group (p<0.01, p<0.001, respectively). Laser irradiation counteracted the softening effect of DDS. Morphologic change was observed in the 2W+DDS group; however, no morphologic changes were observed in the control and the 1W+DDS groups. The mean concentration of minocycline in the periodontal pocket 24 h after application was 252.79±67.50 μg/mL.Conclusions: Laser irradiation of the root surface inhibited the softening and decalcification caused by minocycline HCl. Sealing the periodontal pockets effectively improved drug retention. These results suggest that the combination of laser irradiation and DDS could benefit patients receiving repeated SPT. PMID:24219120

  15. Evaluation of penetration depth of 2% chlorhexidine digluconate into root dentinal tubules using confocal laser scanning microscope

    PubMed Central

    Latha, Jothi; Velmurugan, Natanasabapathy

    2015-01-01

    Objectives This study evaluated the penetration depth of 2% chlorhexidine digluconate (CHX) into root dentinal tubules and the influence of passive ultrasonic irrigation (PUI) using a confocal laser scanning microscope (CLSM). Materials and Methods Twenty freshly extracted anterior teeth were decoronated and instrumented using Mtwo rotary files up to size 40, 4% taper. The samples were randomly divided into two groups (n = 10), that is, conventional syringe irrigation (CSI) and PUI. CHX was mixed with Rhodamine B dye and was used as the final irrigant. The teeth were sectioned at coronal, middle and apical levels and viewed under CLSM to record the penetration depth of CHX. The data were statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests. Results The mean penetration depths of 2% CHX in coronal, middle and apical thirds were 138 µm, 80 µm and 44 µm in CSI group, respectively, whereas the mean penetration depths were 209 µm, 138 µm and 72 µm respectively in PUI group. Statistically significant difference was present between CSI group and PUI group at all three levels (p < 0.01 for coronal third and p < 0.001 for middle and apical thirds). On intragroup analysis, both groups showed statistically significant difference among three levels (p < 0.001). Conclusions Penetration depth of 2% CHX into root dentinal tubules is deeper in coronal third when compared to middle and apical third. PUI aided in deeper penetration of 2% CHX into dentinal tubules when compared to conventional syringe irrigation at all three levels. PMID:25984477

  16. 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

  17. Comparison of the effects of TripleGates and Gates-Glidden burs on cervical dentin thickness and root canal area by using cone beam computed tomography

    PubMed Central

    SOUSA, Kássio; ANDRADE-JUNIOR, Carlos Vieira; da SILVA, Juliana Melo; DUARTE, Marco Antonio Hungaro; DE-DEUS, Gustavo; da SILVA, Emmanuel João Nogueira Leal

    2015-01-01

    The search for new instruments to promote an appropriate cervical preparation has led to the development of new rotary instruments such as TripleGates. However, to the best of the authors' knowledge, there is no study evaluating TripleGates effect on the “risk zone” of mandibular molars. Objectives : The aim of this study was to evaluate the effects of a crown-down sequence of Gates-Glidden and TripleGates burs on the remaining cervical dentin thickness and the total amount of dentin removed from the root canals during the instrumentation by using cone beam computed tomography. The number of separated instruments was also evaluated. Material and Methods : Mesial roots of 40 mandibular first molars were divided into 2 equal groups: crown-down sequence of Gates-Glidden (#3, #2, #1) and TripleGates burs. Cervical dentin thickness and canal area were measured before and after instrumentation by using cone beam computed tomography and image analysis software. Student’s t-test was used to determine significant differences at p<0.05. Results : No significant differences (p>0.05) were observed between the instruments, regarding the root canal area and dentin wall thickness. Conclusion : Both tested instruments used for cervical preparation were safe to be used in the mesial root canal of mandibular molars. PMID:26018308

  18. Microbial biofilm proliferation within sealer-root dentin interfaces is affected by sealer type and aging period

    PubMed Central

    Roth, Karina A; Friedman, Shimon; Lévesque, Céline M; Basrani, Bettina R; Finer, Yoav

    2012-01-01

    Background Root canal fillings are intended to prevent microbial proliferation over time in the canal after treatment. Objective To assess biofilm proliferation within the sealer-dentin interfaces of two methacrylate resin-based systems, self-etch (SE) and total-etch (TE), and an epoxy resin-based sealer (EP), aged for up to 6 months. Methods Standardized specimens (n=45) comprising the coronal 5 mm of human roots were filled with the test materials and gutta-percha. Specimens were either not pre-incubated (control; n=9), or incubated in sterile saline for 1 week, 1 month, 3 months or 6 months (n=3/group). Monospecies biofilms of Enterococcus faecalis were grown on the specimens for 7 days in a chemostat-based biofilm fermentor mimicking pathogenic oral conditions. The extent of E. faecalis proliferation within the sealer-dentin interface for each material and incubation period group was assessed using fluorescence microscopy of dihydroethidium-stained specimens. Results TE had less biofilm proliferation than both EP and SE (p<0.01). Deeper biofilm proliferation was detected in SE and EP specimens aged for 1 and 3 months than those aged for 1 week or 6 months (p<0.05). Maximum depth of biofilm penetration was recorded for SE at 1 month (p<0.05). Conclusion Within the test model used, the self-etch and epoxy resin-based sealers were more susceptible to interfacial biofilm proliferation than the total-etch restorative material. This susceptibility diminished after aging the materials’ interfaces for 6 months. PMID:22892745

  19. Effect of Resin Cement Pre-heating on the Push-out Bond Strength of Fiber Post to Root Canal Dentin.

    PubMed

    Alizadeh Oskoee, Parnian; Nooroloyouni, Ahmad; Pornaghi Azar, Fatemeh; Sajjadi Oskoee, Jafar; Pirzadeh Ashraf, Ahmad

    2015-01-01

    Background and aims. Various factors influence the interfacial bond between the fiber posts and root canal dentin. The aim of the present study was to evaluate the effect of pre-warming of resin cement on the push-out bond strength of fiber posts to various segments of root canal dentin. Materials and methods . In this in vitro study, 40 single-rooted human premolars were decoronated and underwent root canal treatment along with post space preparation. The samples were randomly divided into two groups: In group 1, Panavia F 2.0 cement was used at room temperature; in group 2, the same cement was warmed to 55‒60°C before mixing. After fiber posts were placed and cemented in the root canals, 3 dentin/post sections (coronal, middle and apical) with a thickness of 3 mm were prepared. A universal testing machine was used to measure push-out bond strength in MPa. Data was analyzed using two-factor ANOVA and a post hoc Tukey test at α=0.05. Results. The mean value of push-out bond strength was high at room temperature, and the differences in the means of push-out bond strength values between the resin cement temperatures and between different root segments in each temperature were significant (P<0.05). Conclusion. Pre-warming of Panavia F 2.0 resin cement up to 55-60°C reduced push-out bond strength to root canal dentin. In addition, in each temperature group bond strengths decreased from coronal to apical segments. PMID:26889360

  20. Effect of Resin Cement Pre-heating on the Push-out Bond Strength of Fiber Post to Root Canal Dentin

    PubMed Central

    Alizadeh Oskoee, Parnian; Nooroloyouni, Ahmad; Pornaghi Azar, Fatemeh; Sajjadi Oskoee, Jafar; Pirzadeh Ashraf, Ahmad

    2015-01-01

    Background and aims. Various factors influence the interfacial bond between the fiber posts and root canal dentin. The aim of the present study was to evaluate the effect of pre-warming of resin cement on the push-out bond strength of fiber posts to various segments of root canal dentin. Materials and methods. In this in vitro study, 40 single-rooted human premolars were decoronated and underwent root canal treatment along with post space preparation. The samples were randomly divided into two groups: In group 1, Panavia F 2.0 cement was used at room temperature; in group 2, the same cement was warmed to 55‒60°C before mixing. After fiber posts were placed and cemented in the root canals, 3 dentin/post sections (coronal, middle and apical) with a thickness of 3 mm were prepared. A universal testing machine was used to measure push-out bond strength in MPa. Data was analyzed using two-factor ANOVA and a post hoc Tukey test at α=0.05. Results. The mean value of push-out bond strength was high at room temperature, and the differences in the means of push-out bond strength values between the resin cement temperatures and between different root segments in each temperature were significant (P<0.05). Conclusion. Pre-warming of Panavia F 2.0 resin cement up to 55-60°C reduced push-out bond strength to root canal dentin. In addition, in each temperature group bond strengths decreased from coronal to apical segments. PMID:26889360

  1. Effect of Nd:YAG laser irradiation and fluoride application in the progression of dentin erosion in vitro.

    PubMed

    João-Souza, Samira Helena; Scaramucci, Tais; Hara, Anderson T; Aranha, Ana Cecilia Corrêa

    2015-12-01

    Nd:YAG laser and its association with fluoride have been proposed as an option for the prevention of dental erosion. This study evaluated the progression of existing dentin erosive lesions after treatment with different Nd:YAG laser (1064 nm) protocols, associated or not with fluoride. Erosive lesions were created with 1 % citric acid for 10 min in human dentin specimens. They were randomly assigned into eight groups (n = 15): no treatment (control), 1-min application of 2 % sodium fluoride gel (NaF), Nd:YAG1 (Nd:YAG laser irradiation 0.5 W; 50 mJ; ~41.66 J/cm(2); 10 Hz; 40 s; in contact), Nd:YAG2 (0.7 W; 70 mJ; ~62.50 J/cm(2); 10 Hz; 40 s; in contact), Nd:YAG3 (1 W; 100 mJ; ~54,16 J/cm(2); 10 Hz; 40 s; 1 mm unfocused), NaF + Nd:YAG1, NaF + Nd:YAG2, and NaF + Nd:YAG3. After treatment, the specimens were submitted to a 5-day erosion-remineralization cycling model, 6×/day. Dentin surface loss (SL) was evaluated with optical profilometry after the formation of the initial lesion; after treatment; and after days 1, 3, and 5. Data were statistically analyzed (alpha = 0.05). Significant differences were observed among the groups in all testing times (p < 0.001), except after initial lesion formation. Loss of dentin surface was observed after irradiation with all Nd:YAG laser protocols (p < 0.05). The association fluoride and laser did not differ significantly from laser alone. NaF showed the lowest values of SL and Nd:YAG2 and NaF + Nd:YAG2, the highest. Within the limitations of an in vitro study, it was concluded that laser irradiation, according to the parameters used, was not an appropriated approach to prevent dentin erosion progression, even when it was associated with fluoride. PMID:26370205

  2. Bond strength to root dentin and fluid filtration test of AH Plus/gutta-percha, EndoREZ and RealSeal systems

    PubMed Central

    MAHDI, Alaa Abdul; BOLAÑOS-CARMONA, Victoria; GONZALEZ-LOPEZ, Santiago

    2013-01-01

    Objectives To investigate the bond strength and seal ability produced by AH Plus/gutta-percha, EndoREZ and RealSeal systems to root canal dentin. Material and Methods Sixty extracted single-root human teeth, instrumented manually to size 40, were divided into three groups (n=20) according to the sealer used; G1: AH Plus, G2: EndoREZ, and G3: RealSeal sealers. After filling using the lateral condensation technique, each sealer group was randomly divided into two subgroups according to the tests applied (n=10 for µPush-out test and n=10 for fluid filtration test). A fluid filtration method was used for quantitative evaluation of apical leakage. Four 1-mm-thick slices (cervical and medium level) were obtained from each root sample and a µPush-out test was performed. Failure modes were examined under microscopy at 40x, and a one-way ANOVA was applied to analyze the permeability. Non-parametrical statistics for related (Friedman's and Wilcoxon's rank tests) or unrelated samples (Kruskal-Wallis' and Mann-Whitney's tests) allowed for comparisons of µPush-out strength values among materials at the different levels. Statistical significance was accepted for p values <.05. Results There are no significant differences among fluid filtration of the three sealers. The sealer/core material does not significantly influence the µPush-out bond strength values (F=2.49; p=0.10), although statistically significant differences were detected with regard to root level (Chi2=23.93; p<0.001). AH Plus and RealSeal obtained higher bond strength to intraradicular dentin in the medium root slices. Conclusions There are no significant differences between the permeability and global µPush-out bond strength to root canal dentin achieved by AH Plus/gutta-percha, EndoREZ and RealSeal systems. PMID:24037078

  3. Effect of titanium dioxide and 3.5% hydrogen peroxide with 405-nm diode laser irradiation on bonding of resin to pulp chamber dentin

    NASA Astrophysics Data System (ADS)

    Haruyama, A.; Kato, J.; Kameyama, A.; Hirai, Y.; Oda, Y.

    2010-04-01

    This study was conducted to determine the effect of a 3.5% hydrogen peroxide solution containing titanium dioxide on bonding of resin to pulp chamber dentin. Extracted bovine anterior teeth were allocated to three groups of ten teeth each. The coronal labial pulp chamber dentin was exposed and bleached with 3.5% hydrogen peroxide with titanium dioxide with 405-nm diode laser irradiation for 15 min (Group 1); 30% hydrogen peroxide with halogen lamp irradiation for 15 min (Group 2); and distilled water for 15 min (Group 3). After bleaching, the pulp chamber dentin was prepared for composite resin bonding and the interface between the resin and dentin was observed by scanning electron microscopy. The microtensile bond strength (μTBS) and failure patterns were determined. The μTBS values (mean ± SD) were: 17.28 ± 5.79 MPa ( n = 36), 0 MPa, and 26.50 ± 9.83 MPa ( n = 36) in Groups 1, 2, and 3, respectively. The μTBS in Group 3 was significantly higher than that in Group 1 ( P < 0.05). Hybrid layers and resin tags were clearly observed at the interface in Groups 1 and 3, but not in Group 2. Adhesive failure was mainly observed in Group 1, whereas dentin failure was the main failure pattern in Group 3.

  4. Evaluation of reparative dentin formation of ProRoot MTA, Biodentine and BioAggregate using micro-CT and immunohistochemistry

    PubMed Central

    Kim, Jia; Song, Young-Sang; Min, Kyung-San; Kim, Sun-Hun; Koh, Jeong-Tae

    2016-01-01

    Objectives The purpose of this study was to assess the ability of two new calcium silicate-based pulp-capping materials (Biodentine and BioAggregate) to induce healing in a rat pulp injury model and to compare them with mineral trioxide aggregate (MTA). Materials and Methods Eighteen rats were anesthetized, cavities were prepared and the pulp was capped with either of ProRoot MTA, Biodentine, or BioAggregate. The specimens were scanned using a high-resolution micro-computed tomography (micro-CT) system and were prepared and evaluated histologically and immunohistochemically using dentin sialoprotein (DSP). Results On micro-CT analysis, the ProRoot MTA and Biodentine groups showed significantly thicker hard tissue formation (p < 0.05). On H&E staining, ProRoot MTA showed complete dentin bridge formation with normal pulpal histology. In the Biodentine and BioAggregate groups, a thick, homogeneous hard tissue barrier was observed. The ProRoot MTA specimens showed strong immunopositive reaction for DSP. Conclusions Our results suggest that calcium silicate-based pulp-capping materials induce favorable effects on reparative processes during vital pulp therapy and that both Biodentine and BioAggregate could be considered as alternatives to ProRoot MTA. PMID:26877988

  5. Influence of alveolar bone level on the pull-out bond strength of fiber-reinforced composite posts to root dentin.

    PubMed

    Dal Piva, Amanda Maria de Oliveira; Campos, Fernanda; Alves, Maria Luiza Lima; Sousa, Rafael Santiago; Lima, Júlia Magalhães da Costa; Souza, Rodrigo Othávio Assunção

    2016-01-01

    This in vitro study evaluated the influence of alveolar bone level and type of cement on pull-out bond strength between different fiber-reinforced composite (FRC) posts and root dentin. Sixty bovine teeth were sectioned, and their root canals were prepared. The specimens were divided into 6 groups (n = 10) according to 2 factors: alveolar bone level and type of cement. Each root was embedded in acrylic resin to the depth of 7, 10, or 14 mm, simulating different alveolar bone levels. After the FRC posts were treated with 37% phosphoric acid and silane was applied, they were cemented with either a conventional resin cement or a self-adhesive resin cement and subjected to mechanical cycling. The results indicated that neither the alveolar bone level nor the type of cement played a significant role in the pull-out bond strength of the FRC posts to root dentin. Therefore, it is concluded that conventional and self-adhesive resin cements can be used to lute FRC posts to tooth roots, even in the presence of significant alveolar bone resorption. PMID:26943098

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

    PubMed Central

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

    2009-01-01

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

  7. Pull-out bond strength of a self-adhesive resin cement to NaOCl-treated root dentin: effect of antioxidizing agents

    PubMed Central

    Kachuei, Marzieh

    2014-01-01

    Objectives This study evaluated the effect of three antioxidizing agents on pull-out bond strengths of dentin treated with sodium hypochlorite. Materials and Methods Root canals of 75 single-rooted human teeth were prepared. Fifteen teeth were irrigated with normal saline for a negative control group, and the remaining 60 teeth (groups 2 - 5) with 2.5% NaOCl. The teeth in group 2 served as a positive control. Prior to post cementation, the root canals in groups 3 - 5 were irrigated with three antioxidizing agents including 10% rosmarinic acid (RA, Baridge essence), 10% hesperidin (HPN, Sigma), and 10% sodium ascorbate hydrogel (SA, AppliChem). Seventy-five spreaders (#55, taper .02, Produits Dentaires S.A) were coated with silica and silanized with the Rocatec system and ceramic bond. All the prepared spreaders were cemented with a self-adhesive resin cement (Bifix SE, Voco Gmbh) in the prepared canals. After storage in distilled water (24 h/37℃), the spreaders were pulled out in a universal testing machine at a crosshead speed of 1.0 mm/min. Pull-out strength values were analyzed by one-way ANOVA and Tukey's HSD test (α = 0.05). Results There were significant differences between study groups (p = 0.016). The highest pull-out strength was related to the SA group. The lowest strength was obtained in the positive control group. Conclusions Irrigation with NaOCl during canal preparation decreased bond strength of resin cement to root dentin. Amongst the antioxidants tested, SA had superior results in reversing the diminishing effect of NaOCl irrigation on the bond strength to root dentin. PMID:24790921

  8. Fracture Forces of Dentin after Surface Treatment with High Speed Drill Compared to Er:YAG and Er,Cr:YSGG Laser Irradiation

    PubMed Central

    Franzen, Rene; Kianimanesh, Nasrin; Marx, Rudolf; Ahmed, Asma; Gutknecht, Norbert

    2016-01-01

    Dental tooth restorative procedures may weaken the structural integrity of the tooth, with the possibility of leading to fracture. In this study we present findings of coronal dentin strength after different techniques of surface modification. The fracture strength of dentin beams after superficial material removal with a fine diamond bur high speed drill hand piece, Er:YAG (2.94 μm, 8 J/cm2), and Er,Cr:YSGG (2.78 μm, 7.8 J/cm2) laser irradiation slightly above the ablation threshold was measured by a four-point bending apparatus. Untreated dentin beams served as a control. A total of 58 dentin beams were manufactured from sterilized human extracted molars using the coronal part of the available dentin. Mean values of fracture strength were calculated as 82.0 ± 27.3 MPa for the control group (n = 10), 104.5 ± 26.3 MPa for high speed drill treatment (n = 10), 96.1 ± 28.1 MPa for Er,Cr:YSGG laser irradiation (n = 20), and 89.1 ± 36.3 MPa for Er:YAG laser irradiation (n = 18). Independent Student's t-tests showed no significant difference between each two groups (p > 0.05). Within the parameter settings and the limits of the experimental setup used in this study, both lasers systems as well as the high speed drill do not significantly weaken coronal dentin after surface treatment. PMID:26962473

  9. Fracture Forces of Dentin after Surface Treatment with High Speed Drill Compared to Er:YAG and Er,Cr:YSGG Laser Irradiation.

    PubMed

    Franzen, Rene; Kianimanesh, Nasrin; Marx, Rudolf; Ahmed, Asma; Gutknecht, Norbert

    2016-01-01

    Dental tooth restorative procedures may weaken the structural integrity of the tooth, with the possibility of leading to fracture. In this study we present findings of coronal dentin strength after different techniques of surface modification. The fracture strength of dentin beams after superficial material removal with a fine diamond bur high speed drill hand piece, Er:YAG (2.94 μm, 8 J/cm(2)), and Er,Cr:YSGG (2.78 μm, 7.8 J/cm(2)) laser irradiation slightly above the ablation threshold was measured by a four-point bending apparatus. Untreated dentin beams served as a control. A total of 58 dentin beams were manufactured from sterilized human extracted molars using the coronal part of the available dentin. Mean values of fracture strength were calculated as 82.0 ± 27.3 MPa for the control group (n = 10), 104.5 ± 26.3 MPa for high speed drill treatment (n = 10), 96.1 ± 28.1 MPa for Er,Cr:YSGG laser irradiation (n = 20), and 89.1 ± 36.3 MPa for Er:YAG laser irradiation (n = 18). Independent Student's t-tests showed no significant difference between each two groups (p > 0.05). Within the parameter settings and the limits of the experimental setup used in this study, both lasers systems as well as the high speed drill do not significantly weaken coronal dentin after surface treatment. PMID:26962473

  10. Stress Distribution in Roots Restored with Fiber Posts and An Experimental Dentin Post: 3D-FEA.

    PubMed

    Diana, Hugo Henrique; Oliveira, Juliana Santos; Ferro, Mariana Carolina de Lara; Silva-Sousa, Yara T Corrêa; Gomes, Érica Alves

    2016-04-01

    The aim of this study was to compare the stress distribution in radicular dentin of a maxillary canine restored with either a glass fiber post, carbon fiber post or an experimental dentin post using finite element analysis (3D-FEA). Three 3D virtual models of a maxillary canine restored with a metal-ceramic crown and glass fiber post (GFP), carbon fiber post (CFP), and experimental dentin post (DP) were obtained based on micro-CT images. A total of 180 N was applied on the lingual surface of the incisal third of each tooth at 45 degrees. The models were supported by the periodontal ligament fixed in three axes (x=y=z=0). The von Mises stress (VMS) of radicular dentin and the intracanal posts was calculated. The structures of all groups showed similar values (MPa) and distribution of maximum von Mises stress. Higher stress was found in the apical third of dentin while the posts presented homogeneous stress distribution along the axis. The fiber and dentin posts exhibited similar stress values and distribution. Thus, the experimental dentin post is a promising restorative material. PMID:27058388

  11. An in Vitro Evaluation of Antimicrobial Efficacy of 2% Chlorhexidine Gel, Propolis and Calcium Hydroxide Against Enterococcus faecalis in Human Root Dentin

    PubMed Central

    T S, Ashwini; Patil, Chetan R

    2014-01-01

    Aim: To evaluate in vitro the antimicrobial efficacy of 2% Chlorhexidine gel, Propolis and Calcium hydroxide against Enterococcus faecalis in human root dentin. Methodology: One hundred and twenty human extracted anterior teeth were decoronated below CEJ and the apical part of root was removed to obtain 6mm of middle of the root. GG no 3 was used to standardize the internal diameter of root canal. Dentin blocks were infected with E faecalis for 21 d. They were assigned into four groups (n = 30).Group 1, Saline (negative control); Group 2, Propolis; Group 3, 2% CHX; Group 4, Calcium hydroxide, At the end of 1, 3, and 5 days an assessment of microbial cells was carried out at a depth of 400 μm and colony counts were calculated.The data were analysed statistically with one-way analysis of variance followed by Scheffe multiple comparison test (p < 0.05). Results: The number of colony-forming units was significantly lower in all experimental groups compared to the control group – Saline. 2% Chlorhexidinegluconate produced better antimicrobial efficacy (100%) on day 1, 3 and 5. Propolis (66.37%) had greater antimicrobial activity than Calcium hydroxide (50.89%) on day 1 but there was no significant difference in their antimicrobial activities on day 3 and day 5. Conclusion: 2% Chlorhexidine gel showed the maximum antimicrobial activity against E faecalis and Calcium hydroxide the least. Propolis can be used as an effective alternative intracanal medicament. PMID:25584319

  12. Push-Out Bond Strength of Dorifill, Epiphany and MTA-Fillapex Sealers to Root Canal Dentin with and without Smear Layer

    PubMed Central

    Forough Reyhani, Mohammad; Ghasemi, Negin; Rahimi, Saeed; Salem Milani, Amin; Mokhtari, Hadi; Shakouie, Sahar; Safarvand, Hossein

    2014-01-01

    Introduction: The aim of the present experimental study was to evaluate the push-out bond strength of Dorifill, Epiphany and MTA-Fillapex sealers to root canal dentin in presence and absence of smear layer (SL). Methods and Materials: Sixty human single-rooted teeth were selected and divided into six groups (n=10). The canal irrigation protocol in groups 1, 3 and 5 consisted of 2.5% NaOCl during instrumentation and normal saline at the end of preparation plus a 5-min irrigation with 17% ethylenediaminetetraacetic acid (EDTA). In the remaining groups, normal saline was used for canal irrigation. The root canals were filled with Epiphany/Resilon (groups 1 and 2), Dorifill/gutta-percha (groups 3 and 4) and MTA-Fillapex/gutta-percha (groups 5 and 6). After two weeks of storage in 95% relative humidity at 37ºC, 2 mm-thick dentin disks were prepared from coronal third of each root. The push-out bond strength test was carried out using a universal testing machine. Data were analyzed with the two-way ANOVA and post hoc Tukey’s tests. Statistical significance was defined at 0.05. Results: The highest (3.06±0.38 MPa) and lowest (1.16±0.32 MPa) push-out bond strength values were recorded in Epiphany/Resilon-NaOCl/EDTA and Dorifill/gutta-percha/normal saline groups, respectively. There were significant differences in the bond strength of sealers (P<0.05). In addition, elimination of the SL significantly increased the bond strength of all sealers (P<0.05). Conclusion: The Epiphany/Resilon group exhibited the highest push-out bond strength in the presence and absence of the SL. Elimination of the SL resulted in a significant increase in the bond strength of all the sealers to dentin. PMID:25386203

  13. Phosphoprotein extraction from the dentine/cementum complex of human tooth roots.

    PubMed

    McCurdy, S P; Clarkson, B H; Speirs, R L; Feagin, F F

    1990-01-01

    Root shards were placed in dialysis tubing and demineralized to completion in either 10% disodium EDTA, pH 7.4, 0.6 M HCl, 0.1 M HCl, 0.5 M acetic or 75 mM-25 mM lactic-acetic acids. The demineralized shards were then re-extracted with 0.05 M tris-HCl, 1.0 M NaCl. DEAE chromatography revealed that the major peak of the 0.6 M CHl and EDTA extracts contained organic phosphorus, whereas much less organic phosphorus was found in the major peak of the 0.1 M HCl extract. Analysis of the re-extracts gave a pattern opposite to that obtained from the initial extractions. Measurements of protein and organic phosphorus released during extraction and re-extraction confirmed these results. Staining of SDS-PAGE gels for phosphoprotein with Stains-All resulted in a blue smear in fractions containing organic phosphorus. Thus the extraction of phosphoproteins from human tooth roots differed depending upon the demineralizing conditions. This ability to remove phosphoprotein differentially will allow further investigation of the role of phosphoprotein in mineralization and remineralization. PMID:2115325

  14. Effects of Er:YAG laser irradiation and manipulation treatments on dentin components, part 2: energy-dispersive X-ray fluorescence spectrometry study

    NASA Astrophysics Data System (ADS)

    Silva Soares, Luís Eduardo; Do Espírito Santo, Ana Maria; Brugnera, Aldo; Zanin, Fátima Antônia Aparecida; Martin, Airton Abraha~O.

    2009-03-01

    The effects of laser etching, decontamination, and storage treatments on dentin components were studied by energy-dispersive X-ray fluorescence spectrometry (EDXRF). Thirty bovine incisors were prepared to expose the dentin surface and then divided into two main groups based upon the decontamination process and storage procedure: autoclaved (group A, n=15) or stored in aqueous thymol solution (group B, n=15). The surfaces of the dentin slices were schematically divided into four areas, with each one corresponding to a treatment subgroup. The specimens were either etched with phosphoric acid (control subgroup) or irradiated with erbium-doped yttrium-aluminum-garnet (Er:YAG) laser (subgroups: I-80 mJ, II-120 mJ, and III-180 mJ). Samples were analyzed by micro-EDXRF, yielding three spectra for each area (before and after treatment). Surface mappings covering an area of 80×60 points with steps of 20 μm were also performed on selected specimens. The amount of Ca and P in group A specimens decreased significantly (P<0.05) after the acid etching and the Ca/P ratio increased (P<0.001). Er:YAG laser-etching using lower laser energies did not produce significant changes in dentin components. The mapping data support the hypothesis that acid etching on dentin produced a more chemically homogeneous surface and thus a more favorable surface for the diffusion of adhesive monomers.

  15. Long-term chlorhexidine effect on bond strength to Er:YAG laser irradiated-dentin.

    PubMed

    Galafassi, Daniel; Scatena, Camila; Colucci, Vivian; Rodrigues-Júnior, Antonio Luiz; Campos Serra, Mônica; Corona, Silmara Aparecida Milori

    2014-01-01

    This study evaluates the bond strength of dentin prepared with Er:YAG laser or bur, after rewetting with chlorhexidine on long-term artificial saliva storage and thermocycling. One hundred and twenty human third molars were sectioned in order to expose the dentin surface (n = 10). The specimens were randomly divided in 12 groups according to treatment and aging: Er:YAG laser rewetting with deionized water (LW) and 24 h storage in artificial saliva (WC); LW and 6 months of artificial saliva storage + 12.000 thermocycling (6M), LW and 12 months of artificial saliva storage + 24.000 thermocycling (12M), Er:YAG laser rewetting with 2% chlorhexidine (LC) and WC, LC and 6M, LC and 12M, bur on high-speed turbine rewetting with deionized water (TW) and WC, TW6M, TW12M, bur on high-speed turbine + 2% chlorhexidine (TC) and WC, TC and 6M, TC and 12M. The specimens were etched with 35% phosphoric acid, washed, and dried with air. Single Bond 2 adhesive was applied and the samples were restored with a composite. Each tooth was sectioned in order to obtain 4 sticks, which were submitted to microtensile bond strength test (µTBS). The two-way ANOVA, showed no significant differences for the interaction between the factors and for the aging factor. Tukey 5% showed that the LC group had the lowest µTBS. The rewetting with chlorhexidine negatively influenced the bond strength of the preparation with the Er:YAG laser. The artificial saliva aging and thermocycling did not interfere with dentin bond strength. PMID:24185754

  16. Effect of Resin Cement Porosity on Retention of Glass-Fiber Posts to Root Dentin: An Experimental and Finite Element Analysis.

    PubMed

    Da Silva, Natércia Rezende; Aguiar, Grazielle Crystine Rodrigues; Rodrigues, Monise de Paula; Bicalho, Aline Aredes; Soares, Priscilla Barbosa Ferreira; Veríssimo, Crisnicaw; Soares, Carlos José

    2015-01-01

    The aim of this study was to evaluate the effect of porosity of self-adhesive resin on the stress distribution, post retention and failure mode of fiber post cemented to human root dentin. Ten human central upper incisors with circular root canal were selected. They were sectioned with 15 mm and were endodontically filled. The roots were scanned using micro-CT after post space preparation for root filling remaining evaluation. Fiber posts were cemented using self-adhesive resin cement (Rely X U200, 3M-ESPE). Two 1-mm-thick slices from the cervical, medium and apical thirds were scanned for resin cement bubbles volume measurements and submitted to a push-out test (PBS). Three operators using stereomicroscopy and confocal laser microscopy classified the failure mode. Stress distributions during the push-out test were analyzed using 3D finite element analysis. PBS values (MPa) were submitted to one-way ANOVA and Tukey's post hoc tests and the failure modes using the Kappa coefficient to assess inter-operator agreement. Chi-square test was used to determine significant differences between the methods ( = 0.05). Push-out bond strength was significantly affected by the bubbles presence in all root depth (p<0.05). The stress concentration was higher when the bubbles were present. Adhesive dentin/resin cement interface failure was the most frequent type of failure. Confocal microscopy was better than stereomicroscopy for failure analysis. Bubbles generated during resin cement insertion into the root canal negatively affect the stress distribution and the bond strength. The use of confocal microscopy is recommended for failure analysis. PMID:26963208

  17. Infected Dentine Revisited.

    PubMed

    Kidd, Edwina; Fejerskov, Ole; Nyvad, Bente

    2015-11-01

    Dentine becomes infected as a result of caries lesion formation on root surfaces and when lesions progress following cavitation of enamel lesions. However, this infection is unimportant because the driving force for lesion formation and progression is the overlying biofilm. This explains why root surface caries can be controlled by mechanical plaque control and fluoride, and restorations are not needed to arrest these lesions. Similarly, the infected dentine in cavitated coronal lesions does not have to be removed to arrest the lesion. If the lesion is either accessible or opened for cleaning by the patient or parent, the lesion can be arrested. Sealing of infected dentine within the tooth, either by a Hall crown in the primary dentition or by partial caries removal prior to placing a well-sealed filling, will also arrest the lesion. When restoring deep lesions in symptomless, vital teeth, vigorous excavation of infected dentine is likely to expose the pulp and make root canal treatment necessary. Thus complete excavation'is not needed and should be avoided. CPD/CLINICAL RELEVANCE: Root surface caries can be arrested by cleaning and fluoride application. Restorations are not essential. Vigorous excavation of softened dentine in deep cavities of symptomless, vital teeth is contra-indicated. It is not needed and increases the risk of pulp exposure. PMID:26749788

  18. Temperature changes on the root surfaces of mandibular incisors after an 810-nm high-intensity intracanal diode laser irradiation

    NASA Astrophysics Data System (ADS)

    da Fonseca Alvarez, Andrea; Moura-Netto, Cacio; Daliberto Frugoli, Alexandre; Fernando, Casemiro; Correa Aranha, Ana Cecilia; Davidowicz, Harry

    2012-01-01

    Temperature changes caused by laser irradiation can promote damage to the surrounding dental tissues. In this study, we evaluated the temperature changes of recently extracted human mandibular incisors during intracanal irradiation with an 810-nm diode laser at different settings. Fifty mandibular incisors were enlarged up to an apical size of ISO No. 40 file. After the final rinse with 17% ethylenediaminetetraacetic acid, 0.2% lauryl sodium sulfate biologic detergent, and sterile water, samples were irradiated with circular movements from apex to crown through five different settings of output power (1.5, 2.0, 2.5, 3.0, and 3.5 W) in continuous mode. The temperature changes were measured on both sides of the apical and middle root thirds using two thermopar devices. A temperature increase of 7 °C was considered acceptable as a safe threshold when applying the diode laser. Results: The results showed that only 3.5-W output power increased the outer surface temperature above the critical value. Conclusion: The recommended output power can be stipulated as equal to or less than 3 W to avoid overheating during diode laser irradiation on thin dentin walls.

  19. Rootless teeth: Dentin dysplasia type I

    PubMed Central

    Fulari, Sangamesh G; Tambake, Deepti P

    2013-01-01

    A rare case of hereditary disturbance of dentine, Dentin dysplasia type I is presented, which is characterized by short or total absence of roots, obliterated pulp chambers, and peri-apical radiolucencies. It affects both primary and secondary dentition. Management of patients with dentinal dysplasia is difficult and requires a multidisciplinary approach. An overview of dentin dysplasia and its management along with a case report is discussed. PMID:24403801

  20. Combination of aligned PLGA/Gelatin electrospun sheets, native dental pulp extracellular matrix and treated dentin matrix as substrates for tooth root regeneration.

    PubMed

    Chen, Gang; Chen, Jinlong; Yang, Bo; Li, Lei; Luo, Xiangyou; Zhang, Xuexin; Feng, Lian; Jiang, Zongting; Yu, Mei; Guo, Weihua; Tian, Weidong

    2015-06-01

    In tissue engineering, scaffold materials provide effective structural support to promote the repair of damaged tissues or organs through simulating the extracellular matrix (ECM) microenvironments for stem cells. This study hypothesized that simulating the ECM microenvironments of periodontium and dental pulp/dentin complexes would contribute to the regeneration of tooth root. Here, aligned PLGA/Gelatin electrospun sheet (APES), treated dentin matrix (TDM) and native dental pulp extracellular matrix (DPEM) were fabricated and combined into APES/TDM and DPEM/TDM for periodontium and dental pulp regeneration, respectively. This study firstly examined the physicochemical properties and biocompatibilities of both APES and DPEM in vitro, and further investigated the degradation of APES and revascularization of DPEM in vivo. Then, the potency of APES/TDM and DPEM/TDM in odontogenic induction was evaluated via co-culture with dental stem cells. Finally, we verified the periodontium and dental pulp/dentin complex regeneration in the jaw of miniature swine. Results showed that APES possessed aligned fiber orientation which guided cell proliferation while DPEM preserved the intrinsic fiber structure and ECM proteins. Importantly, both APES/TDM and DPEM/TDM facilitated the odontogenic differentiation of dental stem cells in vitro. Seeded with stem cells, the sandwich composites (APES/TDM/DPEM) generated tooth root-like tissues after being transplanted in porcine jaws for 12 w. In dental pulp/dentin complex-like tissues, columnar odontoblasts-like layer arranged along the interface between newly-formed predentin matrix and dental pulp-like tissues in which blood vessels could be found; in periodontium complex-like tissues, cellular cementum and periodontal ligament (PDL)-like tissues were generated on the TDM surface. Thus, above results suggest that APES and DPEM exhibiting appropriate physicochemical properties and well biocompatibilities, in accompany with TDM, could

  1. Dentin Sialophophoprotein (DSPP) and Dentin

    PubMed Central

    Yamakoshi, Yasuo

    2009-01-01

    The revolution in genetics disclosed the types of malformations that occur when expression of a particular gene is lost. In the case of tooth dentin, mutations in the two genes encoding type I collagen cause osteogenesis imperfecta, a bone condition that often includes dentin malformations. Besides collagen, there are a number of non-collagenous proteins in dentin. Among the genes encoding the dentin non-collagenous proteins, only mutations in DSPP (dentin sialophosphoprotein) cause inherited dental malformations. DSPP mutations cause dentinogenesis imperfecta types II and III, and dentin dysplasia type II. DSPP is the most abundant non-collagenous protein in dentin. DSPP protein is necessary for proper dentin formation, and understanding its structure and function should yield important insights into how dentin forms and biomineralization is controlled. DSPP is expressed and secreted by odontoblasts, the cells that make tooth dentin and that also maintain cell processes extending into the mineralized tissue. Following its secretion, DSPP is cleaved into smaller pieces by multiple extracellular proteases. For the last five years I have devoted myself to characterizing DSPP-derived proteins. DSPP is cleaved by proteases into three main parts : dentin sialoprotein (DSP), dentin glycoprotein (DGP), and dentin phosphoprotein (DPP). We have learned that DSP is a proteoglycan that forms covalent dimers, DGP is a phosphorylated glycoprotein, and DPP is a highly phosphorylated intrinsically disordered protein that shows extensive length polymorphisms due to the genetic heterogeneity of its coding region. PMID:20037676

  2. Push-out bond strength of quartz fibre posts to root canal dentin using total-etch and self-adhesive resin cements

    PubMed Central

    Mohammadi, Narmin; Navimipour, Elmira J.; Shakerifar, Maryam

    2012-01-01

    Objectives: Several adhesive systems are available for cementation of fibre posts into the root canal. The aim of the present study was to investigate the push-out bond strengths of quartz fibre posts to root dentin with the use of different total-etch and self-adhesive resin cements. Study Design: Ninety single-rooted human premolars were endodontically treated and standardized post-spaces were prepared. Fibre posts were cemented with different luting agents: total-etch (Nexus NX3, Duo-Link, and RelyX ARC) and self-adhesive resin cements (Maxcem Elite, BisCem, and RelyX Unicem). Three post/dentin sections (coronal, middle and apical) were obtained from each specimen, and push-out bond strength test was performed in each section at a cross-head speed of 0.5 mm/min. Data was analyzed with two-factor and one-way analysis of variance and a post-hoc Tukey test at a significance level of p < 0.05. Results: Cement type, canal region, and their interaction significantly influenced bond strength. Significantly higher bond strength values were observed in the apical region of self-adhesive cements. Only Duo-Link and RelyX ARC cements resulted in homogeneous bond strengths. Conclusions: Cementation of quartz fibre posts using self-adhesive cements provided higher push-out bond strengths especially in the apical region, while total-etch cements resulted in more uniform bond strengths in different regions of the root canal. Key words: Push-out bond strength; quartz fibre post; total-etch resin cement; self-adhesive resin cement. PMID:22143695

  3. Dentin ablation-rate measurements in endodontics witj HF and CO2 laser radiation

    NASA Astrophysics Data System (ADS)

    Makropoulou, Mersini I.; Serafetinides, Alexander A.; Khabbaz, Marouan; Sykaras, Sotirios; Tsikrikas, G. N.

    1996-01-01

    Recent studies focused on the ability of the laser light to enlarge the root canal during the endodontic therapy. The aim of this research is the experimental and theoretical study of the ablation rate of two infrared laser wavelengths on dentin. Thirty freshly extracted human teeth were longitudinally sectioned at thicknesses ranged from 0.5 to 2 mm, and irradiated on the root canal dentin. The measured ablation rates in dentinal wall of the root canal showed that the HF laser at 2.9 micrometer can more effectively penetrate into the tissue, whereas the carbon dioxide laser at 10.6 micrometer leads to high thermal damage of the ablation crater surroundings.

  4. Optical properties of human radicular dentin: ATR-FTIR characterization and dentine tubule direction influence on radicular post adhesion

    NASA Astrophysics Data System (ADS)

    Quinto, Jose; Zamataro, Claudia B.; Benetti, Carolina; Dias, Derly A.; Blay, Alberto; Zezell, Denise Maria

    2015-06-01

    Knowledge of dental structures is essential for understanding of laser interaction and its consequences during adhesion processes. Tubule density in dentin ranges from 4.900 to 90.000 per mm2, for diameters from 1 to 3 μm. Light propagation inside the tubules is associated with tubules orientation. To the best of our knowledge, there is no previous work in literature characterizing physical-chemical alterations in dentin. The dentin samples were irradiated with a Er,Cr:YSGG Laser at wavelength 2.78 μm, with an energy density of 9.46 J/cm2 , above the ablation threshold. ATRFTIR at wavenumbers 2000 to 700 cm-1 was used to evaluate the differences among third root region and tubules orientation.

  5. A Comparative Study on Micro Hardness and Structural Changes of Dentin Floor Cavity Prepared by Er: YAG Laser Irradiation and Mechanical Bur

    PubMed Central

    Arbabzadeh, F; Birang, E; Nazem, R; Abbasian, M; Koosha, F; Birang, R

    2013-01-01

    Statement of Problem: Laser irradiation makes structural and chemical changes on the dental hard tissues. These changes alter the level of solubility and permeability of dentin. Purpose: The aim of this study was to compare the microhardness and the structural changes in the dentin cavity floor prepared with Er: YAG laser and bur. Material and Methods: In this experimental study, fifteen intact human molars were selected. Two square cavities were prepared on the buccal and lingual surfaces of each tooth. One side was randomly prepared by Er:YAG laser and the other side by bur. The specimens were divided into two halves. Consequently, there were 30 samples in every group. One half was assigned for the Vickers’s hardness test and the other one, for determination of Ca and P percentage and atomic elements analysis. The data were analyzed by Paired T-tests through SPSS16 (α≤o.o5). Results: The means and the standard deviation of the microhardness were 69.77±25.62 and 51.33±9.31 Kg/mm2 in the laser and bur groups, respectively. Statistical analysis showed significant differences between the two groups (p=0.017). Weight percentage of calcium in the laser cavity (65.5) was less than the bur cavities (68.21) and the difference was significant (p= 0.037). Conclusion: The hardness of dentin in laser group was higher than the bur group because of the higher mineral content of the dentin. The hardness and the mineral content of dentin are important factors in the bonding effectiveness of the dental materials so with laser cavity preparation, good mineral substrate are available for a better bonding. PMID:24724123

  6. Effect of chlorhexidine on bond strength between glass-fiber post and root canal dentine after six month of water storage.

    PubMed

    Toman, M; Toksavul, S; Tamaç, E; Sarikanat, M; Karagözoğlu, I

    2014-03-01

    Aim of this study was to assess the influence of chlorhexidine digluconate (CHX) application on bond strength of glass fibre reinforced composite (FRC) posts to root dentine using adhesive luting systems. Forty extracted human mandibular premolars were endodontically treated and root canals were prepared. Teeth were divided into 2 groups according to luting system as SuperBond C&B (etch-and-rinse/chemical cure) and FuturaBond DC (self-etch/ dual cure). Each group was further divided in 2 subgroups (n=10) according to whether CHX was applied or not. Group Futura/CHX: FuturaBond DC + CHX; group Futura: FuturaBond DC; group Super/CHX: Super Bond C&B + CHX; group Super: SuperBond C&B + CHX. Mean and standard deviation (in parenthesis) values of bond strength in MPa were: group Futura/CHX: 8.86 (1.96), group Futura: 7.65 (1.01), group Super/CHX: 17.47(2.93), group Super: 12.41 (3.83). Bond strength values were affected by the type of luting agent and CHX irrigation (p=0.001, two-way ANOVA). There were statistically significant differences among the groups according to one-way ANOVA (p<0.001). Significant differences were observed in bond strength between groups Super/CHX and Super (p=0.023), between groups Futura/CHX and Super/CHX (p<0.001). Application of CHX before luting procedure with etch-and-rinse/chemical cure luting agent of glass FRC post improved long-term bond strength between glass FRC and root dentine. PMID:24922997

  7. Intrapulpal temperatures during pulsed Nd:YAG laser treatment of dentin, in vitro.

    PubMed

    White, J M; Fagan, M C; Goodis, H E

    1994-03-01

    Lasers are being used for soft tissue removal, caries removal, and treatment of root surface sensitivity. One concern for laser safety is that the heat produced at the irradiated root surface may diffuse to the pulp causing irreversible pulpal damage. To test this heat diffusion, copper-constantan thermocouples were inserted into the radicular pulp canals of extracted teeth. Simulating direct exposure which might occur during gingival excision, superficial caries removal, and modification of the dentin surface for treatment of root surface sensitivity, a 2 mm2 area of the external root surface was uniformly irradiated with a pulsed Nd:YAG laser using a 320 microns diameter fiber optic contact probe. Power was varied from 0.3 to 3.0 W with frequencies of 10 and 20 Hz. Temperature changes during cavity preparations using a high speed handpiece with air coolant were also recorded. Repeated measures ANOVA (P < or = 0.05) indicated that intrapulpal temperatures increased as a function of power, frequency, and time. Intrapulpal temperatures decreased as remaining dentin thickness (0.2 to 2.0 mm) increased for each laser parameter. Irradiation of dentin using a Nd:YAG pulsed laser, within the treatment times, powers, and frequencies with adequate remaining dentin thickness, as outlined in this paper, should not cause devitalizing intrapulpal temperature rises. PMID:8164119

  8. The influence of the Q-switched and free-running Er:YAG laser beam characteristics on the ablation of root canal dentine

    NASA Astrophysics Data System (ADS)

    Papagiakoumou, Eirini; Papadopoulos, Dimitrios N.; Khabbaz, Marouan G.; Makropoulou, Mersini I.; Serafetinides, Alexander A.

    2004-06-01

    Laser based dental treatment is attractive to many researchers. Lasers in the 3 μm region, as the Er:YAG, are suitable especially for endodontic applications. In this study a pulsed free-running and Q-switched laser was used for the ablation experiments of root canal dentine. The laser beam was either directly focused on the dental tissue or delivered to it through an infrared fiber. For different spatial beam distributions, energies, number of pulses and both laser operations the quality characteristics (crater's shape formation, ablation efficiency and surface characteristics modification) were evaluated using scanning electron microscopy (SEM). The craters produced, generally, reflect the relevant beam profile. Inhomogeneous spatial beam profiles and short pulse duration result in cracks formation and lower tissue removal efficiency, while longer pulse durations cause hard dentine fusion. Any beam profile modification, due to laser characteristics variations and the specific delivering system properties, is directly reflected in the ablation crater shape and the tissue removal efficiency. Therefore, the laser parameters, as fluence, pulse repetition rate and number of pulses, have to be carefully adjusted in relation to the desirable result.

  9. Stress distribution on dentin-cement-post interface varying root canal and glass fiber post diameters. A three-dimensional finite element analysis based on micro-CT data

    PubMed Central

    LAZARI, Priscilla Cardoso; de OLIVEIRA, Rodrigo Caldeira Nunes; ANCHIETA, Rodolfo Bruniera; de ALMEIDA, Erika Oliveira; FREITAS JUNIOR, Amilcar Chagas; KINA, Sidney; ROCHA, Eduardo Passos

    2013-01-01

    Objective The aim of the present study was to analyze the influence of root canal and glass fiber post diameters on the biomechanical behavior of the dentin/cement/post interface of a root-filled tooth using 3D finite element analysis. Material and Methods Six models were built using micro-CT imaging data and SolidWorks 2007 software, varying the root canal (C) and the glass fiber post (P) diameters: C1P1-C=1 mm and P=1 mm; C2P1-C=2 mm and P=1 mm; C2P2-C=2 mm and P=2 mm; C3P1-C=3 mm and P=1 mm; C3P2-C=3 mm and P=2 mm; and C3P3-C=3 mm and P=3 mm. The numerical analysis was conducted with ANSYS Workbench 10.0. An oblique force (180 N at 45º) was applied to the palatal surface of the central incisor. The periodontal ligament surface was constrained on the three axes (x=y=z=0). Maximum principal stress (σmax) values were evaluated for the root dentin, cement layer, and glass fiber post. Results: The most evident stress was observed in the glass fiber post at C3P1 (323 MPa), and the maximum stress in the cement layer occurred at C1P1 (43.2 MPa). The stress on the root dentin was almost constant in all models with a peak in tension at C2P1 (64.5 MPa). Conclusion The greatest discrepancy between root canal and post diameters is favorable for stress concentration at the post surface. The dentin remaining after the various root canal preparations did not increase the stress levels on the root. PMID:24473716

  10. Thermal and microstructural effects of nanosecond pulsed Nd:YAG laser irradiation on tooth root surface

    NASA Astrophysics Data System (ADS)

    Wilder-Smith, Petra B. B.; Arrastia-Jitosho, Anna-Marie A.; Grill, G.; Liaw, Lih-Huei L.; Berns, Michael W.

    1995-05-01

    Plaque, calculus and altered cementum removal by scaling and root planing is a fundamental procedure in periodontal treatment. However, the residual smear layer contains cytotoxic and inflammatory mediators which adversely affect healing. Chemical smear layer removal is also problematic. In previous investigations effective smear layer removal was achieved using long pulsed irradiation at 1.06 (mu) . However, laser irradiation was not adequate as an alternative to scaling and root planing procedures and concurrent temperature rises exceeded thermal thresholds for pulpal and periodontal safety. It was the aim of this study to determine whether nanosecond pulsed irradiation at 1.06 (mu) could be used as an alternative or an adjunct to scaling and root planing. Sixty freshly extracted teeth were divided as follows: 5 control, 5 root planed only, 25 irradiated only, 25 root planed and irradiated. Irradiation was performed at fluences of 0.5 - 2.7 J/cm2, total energy densities of 12 - 300 J/cm2, frequencies of 2 - 10 Hz using the Medlite (Continuum) laser. Irradiation-induced thermal events were recorded using a thermocouple within the root canal and a thermal camera to monitor surface temperatures. SEM demonstrated effective smear layer removal with minimal microstructural effects. Surface temperatures increased minimally (< 3 C) at all parameters, intrapulpal temperature rises remained below 4 C at 2 and 5 Hz, F < 0.5 J/cm2. Without prior scaling and root planing, laser effects did not provide an adequately clean root surface.

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

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

  12. Effect of high energy X-ray irradiation on the nano-mechanical properties of human enamel and dentine.

    PubMed

    Liang, Xue; Zhang, Jing Yang; Cheng, Iek Ka; Li, Ji Yao

    2016-01-01

    Radiotherapy for malignancies in the head and neck can cause common complications that can result in tooth damage that are also known as radiation caries. The aim of this study was to examine damage to the surface topography and calculate changes in friction behavior and the nano-mechanical properties (elastic modulus, nanohardness and friction coefficient) of enamel and dentine from extracted human third molars caused by exposure to radiation. Enamel and dentine samples from 50 human third molars were randomly assigned to four test groups or a control group. The test groups were exposed to high energy X-rays at 2 Gy/day, 5 days/week for 5 days (10 Gy group), 15 days (30 Gy group), 25 days (50 Gy group), 35 days (70 Gy group); the control group was not exposed. The nanohardness, elastic modulus, and friction coefficient were analyzed using a Hysitron Triboindenter. The nano-mechanical properties of both enamel and dentine showed significant dose-response relationships. The nanohardness and elastic modulus were most variable between 30-50 Gy, while the friction coefficient was most variable between 0-10 Gy for dentine and 30-50 Gy for enamel. After exposure to X-rays, the fracture resistance of the teeth clearly decreased (rapidly increasing friction coefficient with increasing doses under the same load), and they were more fragile. These nano-mechanical changes in dental hard tissue may increase the susceptibility to caries. Radiotherapy caused nano-mechanical changes in dentine and enamel that were dose related. The key doses were 30-50 Gy and the key time points occurred during the 15th-25th days of treatment, which is when application of measures to prevent radiation caries should be considered. PMID:26676192

  13. Comparative evaluation of fracture resistance of root dentin to resin sealers and a MTA sealer: An in vitro study

    PubMed Central

    Mandava, Jyothi; Chang, Pin Chen; Roopesh, B; Faruddin, Md Ghazan; Anupreeta, A; Uma, Ch

    2014-01-01

    Background: Endodontic obturating materials should form monoblocks, reinforcing the treated teeth against fracture. Aim: To evaluate and compare the effect of two resin sealers and a MTA sealer on the fracture resistance of endodontically treated teeth. Materials and Methods: Fifty single-rooted mandibular premolars, decoronated at cemento-enamel junction, were divided into 5 groups (n = 10 each). Group 1 and group 2 served as negative and positive controls. Cleaning and shaping of root canals was done using ProTaper rotary files and 3% sodium hypochlorite irrigation. Obturation was done using AH plus (Dentsply, Germany) (group 3), MetaSEAL (Parkell, USA) (group 4), MTA Fillapex (Angeles, Brazil) (group 5) sealers and gutta-percha. Teeth were subjected to vertical loading using a universal testing machine and the point at which fracture of the roots occurred was recorded. The data was subjected to statistical analysis using one way analysis of variance (ANOVA) followed by pair-wise comparison using Tukey's Post-hoc test. Results: AH Plus showed better fracture resistance among the sealer groups. Statistically, no significant difference was found between MetaSEAL and Fillapex groups. Conclusion: MTA Fillapex as a root canal sealer was not able to reinforce the tooth against fracture. PMID:24554862

  14. Dentin dysplasia: single-tooth involvement?

    PubMed

    Naik, Veena V; Kale, Alka D

    2009-03-01

    Dentin dysplasia is a genetic defect of dentin formation inherited as an autosomal dominant trait. It is characterized by normal enamel but atypical dentin formation with abnormal pulpal morphology. Once thought to be a single entity, dentin dysplasia has now been divided into type I (radicular) and II (coronal). Type I is by far the more common. Both types include multiple/generalized involvement of primary and permanent dentition. Combinations of both types have also been described in the literature. Four distinct forms of dentin dysplasia type I and 1 form of dentin dysplasia type II are identified. Although there seems to be no need to identify more than 2 distinct types of this relatively rare inherited defect of human dentin, the possible existence of additional forms of the disease cannot be ruled out. Here is a case report of dentin dysplasia in a single tooth, with crown and roots of normal dimensions, associated with severe pain and mobility and histologically involving both coronal and radicular dentin. Focal odontoblastic dysplasia or dentin dysplasia type III could be the new entity. PMID:19417880

  15. A Roughness Study of Ytterbium-Doped Potassium Yttrium Tungstate (YB: KYW) Thin-Disk Femtosecond Ablated Dentin

    PubMed Central

    Liu, Jing; Chen, Hu; Ge, Wenqi; Wang, Yongbo; Sun, Yuchun; Wang, Yong; Lü, Peijun

    2014-01-01

    Introduction: The aim of this study was to evaluate the morphological changes and quantitatively assess the roughness of dentin after the ablation with a Ytterbium-Doped Potassium Yttrium Tungstate (YB: KYW) thin-disk femtosecond pulsed laser of different fluences, scanning speeds and scanning distances. Method: Twelve extracted human premolars were sectioned into crowns and roots along the cementum-enamel junction, and then the crowns were cut longitudinally into sheets about 1.5 mm thick with a cutting machine. The dentin samples were fixed on a stage at focus plane. The laser beam was irradiated onto the samples through a galvanometric scanning system, so rectangular movement could be achieved. After ablation, the samples were examined with a scanning electron microscope and laser three-dimensional profile measurement microscope for morphology and roughness study.With increasing laser fluence, dentin samples exhibited more melting and resolidification of dentin as well as debris-like structure and occluded parts of dentinal tubules. Results: When at the scanning speed of 2400mm/s and scanning distance of 24μm, the surface roughness of dentin ablated with femtosecond pulsed laser decreased significantly and varied between values of dentin surface roughness grinded with two kinds of diamond burs with different grits. When at the scanning speed of 1200mm/s and scanning distance of 12μm, the surface roughness decreased slightly, and the surface roughness of dentin ablated with femtosecond pulsed laser was almost equal to that grinded with a low grit diamond bur. Conclusion: This study showed that increased laser influence may lead to more collateral damage and lower dentin surface roughness, while scanning speed and scanning distance were also negatively correlated with surface roughness. Adequate parameters should be chosen to achieve therapeutic benefits, and different parameters can result in diverse ablation results. PMID:25606337

  16. Role of Dentin Compositional Changes and Structural Loss on Fracture Predilection in Endodontically Treated Teeth

    NASA Astrophysics Data System (ADS)

    Ossareh, Arezou

    The aim of this study was to examine the role of chemical compositional changes and iatrogenic dentin structural loss on the mechanical response of teeth to force and resistance to fracture. The experiments were divided into three phases. In phase 1, experimental studies were performed to evaluate the effect of chemicals used during treatment on ultrastructure, composition and resistance to fracture of dentin. In phase 2, experimental studies were used to evaluate the influence of dentin removal and remaining dentin volume on the resistance to fracture and microcrack formation in root dentin. In phase 3 finite element analysis was carried out to examine the influence of dentin loss on the stress distribution in root dentin. The combination of experimental and numerical analysis highlighted the role of remaining dentin volume and moment of inertia on root dentin biomechanics.

  17. Effect of Gamma-irradiation and Heat on Root-knot Nematode, Meloidogyne javanica

    PubMed Central

    Chinnasri, B.; Moy, J. H.; Sipes, B. S.; Schmitt, D. P.

    1997-01-01

    Effects of gamma-irradiation on the root-knot nematode Meloidogyne javanica were investigated. A dose of 7.5 kGy killed all second-stage juveniles (J2) within 1 day after treatment. Egg hatch was completely inhibited at 6.25 kGy. A bioassay on tomato measuring galling and egg production was used to determine the infectivity of irradiated J2 and J2 hatched from irradiated eggs. The J2 and eggs irradiated with a dose of 4.25 kGy did not induce galls or reproduce on tomato plants. When nematodes were exposed to combined irradiation and heat treatment, no synergistic effect on J2 or eggs was measured. Heat treatment at 49° C for 10 minutes or 20 minutes without irradiation immobilized J2 and prevented egg development. Irradiation rates needed to kill or incapacitate M. javanica were high and may be impractical as a quarantine measure. PMID:19274131

  18. Influence of instrumentation techniques and irrigating solutions on bond strength of glass fiber posts to root dentin.

    PubMed

    Marques, Eduardo Fernandes; Bueno, Carlos Eduardo da Silveira; Veloso, Heloisa Helena Pinho; Almeida, Gustavo; Pinheiro, Sergio Luiz

    2014-01-01

    This study sought to evaluate how instrumentation techniques and irrigating solutions affected the bond strength of glass fiber posts. For this study, 80 human maxillary central incisors were selected. Endodontic access was obtained, root canal length was measured, and the coronal third was prepared using Gates-Glidden drills. The specimens were embedded in acrylic resin and randomly assigned to 8 groups (n = 10): manual instrumentation only (Group 1), rotary instrumentation only (Group 2), irrigation with 2.5% sodium hypochlorite (NaOCl) (Group 3), irrigation with 2% chlorhexidine (CHX) (Group 4), manual instrumentation and irrigation with 2.5% NaOCl (Group 5), manual instrumentation and irrigation with 2% CHX (Group 6), rotary instrumentation and irrigation with 2.5% NaOCl (Group 7), and rotary instrumentation and irrigation with 2% CHX (Group 8). Specimens in Groups 5-8 also received a 1 minute final rinse with ethylenediaminetetraacetic acid. Canals were filled and the specimens stored for 30 days in distilled water. The restoration material was removed down to the apical 4 mm of the root canal. The glass fiber posts were luted with resin cement and stored for 24 hours at 37°C. Specimens were subjected to a tensile strength test at a constant speed of 1.0 mm/minute and a load of 2,000 kgf. The results were analyzed by analysis of variance and Tukey's test. Irrigation with 2.5% NaOCl reduced the bond strength of fiber posts significantly (P < 0.01), while CHX showed no effect (P > 0.05). It was concluded that irrigation with 2.5% NaOCl has a negative effect on micromechanical retention of glass fiber posts, whether manual or rotary instrumentation is used. PMID:24598496

  19. Effect of light-curing units on push-out fiber post bond strength in root canal dentin

    NASA Astrophysics Data System (ADS)

    Calixto, L. R.; Bandéca, M. C.; Silva, F. B.; Rastelli, A. N. S.; Porto-Neto, S. T.; Andrade, M. F.

    2009-08-01

    The purpose of this study was to evaluate the effectiveness of different light-curing units on the bond strength (push-out) of glass fiber posts in the different thirds of the root (cervical, middle and apical) with different adhesive luting resin systems (dual-cure total-etch; dual-cured and self-etch bonding system; and dual-cure self-adhesive cements), Disks of the samples ( n = 144) were used, with approximately 1 mm of thickness of 48 bovine roots restored with glass fiber posts, that were luted with resin cements photo-activated by halogen LCU (QTH, Optilux 501) and blue LED (Ultraled), with power densities of 600 and 550 mW/cm2, respectively. A universal testing machine (MTS 810 Material Test System) was used with a 1 mm diameter steel rod at cross-head speed of 0.5 mm/min until post extrusion, with load cell of 50 kg, for evaluation of the push-out strength in the different thirds of each sample. The push-out strength values in kgf were converted to MPa and analyzed through Analysis of Variance and Tukey’s test, at significance level of 5%. The results showed that there were no statistical differences between the QTH and LED LCUs. The self-adhesive resin cement had lower values of retention. The total-etch and self-adhesive system resin cements seem to be a possible alternative for glass fiber posts cementation into the radicular canal and the LED LCU can be applied as an alternative to halogen light on photo-activation of dual-cured resin cements.

  20. Functional remineralization of carious dentin

    NASA Astrophysics Data System (ADS)

    Pugach, Megan Kardon

    A primary goal of dental tissue engineering is the biological reconstruction of tooth substrate destroyed by caries or other diseases affecting tooth mineralization. Traditionally, dentists treat caries by using invasive techniques to remove the diseased dental tissue and restore the lesion, ideally preventing further progression of decay. Success in strategies associated with remineralization of enamel and root caries have contributed to the less invasive prospect of remineralization of dentinal carious lesions. The central hypothesis of this dissertation is that carious dentin lesions can be remineralized if the lesions contain residual mineral. Caries Detector (CD) stained zones (pink, light pink, transparent and normal) of arrested carious dentin lesions were characterized according to microstructure by atomic force microscopy (AFM) imaging, mineral content by digital transverse microradiography, and nanomechanical properties by AFM-based nanoindentation. CD-stained and unstained zones had significantly different microstructure, mineral content and nanomechanical properties. Furthermore, the most demineralized carious zone contained residual mineral. To obtain reproducible, standardized dentin caries lesions, we characterized the lesions from an artificial carious dentin lesion model using a 0.05M acetate demineralization buffer. The artificial caries-like lesions produced by the buffer had similar mineral content and nanomechanical properties in the stained and unstained zones as natural dentin lesions. Both natural and artificial lesions had significant correlations between mineral content and nanomechanical properties. Mineral crystallite size and shape was examined by small angle x-ray scattering. Both natural and artificial carious dentin had different mineral sizes than normal dentin. Collagen in natural and artificial carious dentin lesions was examined by trichrome stain, AFM high-resolution imaging, and UV resonance Raman spectroscopy, to determine if

  1. Phase, compositional, and morphological changes of human dentin after Nd:YAG laser treatment.

    PubMed

    Lin, C P; Lee, B S; Lin, F H; Kok, S H; Lan, W H

    2001-06-01

    Although techniques for repairing root fracture have been proposed, the prognosis is generally poor. If the fusion of a root fracture by laser is possible, it will offer an alternative to extraction. Our group has attempted to use lasers to fuse a low melting-point bioactive glass to fractured dentin. This report is focused on the phase, compositional, and morphological changes observed by means of X-ray diffractometer, Fourier transforming infrared spectroscopy, and scanning electron microscopy-energy dispersive X-ray spectroscopy in human dentin after exposure to Nd:YAG laser. The irradiation energies were from 150 mJ/ pulse-10 pps-4 s to 150 mJ/pulse-30 pps-4 s. After exposure to Nd:YAG laser, dentin showed four peaks on the X-ray diffractometer that corresponding to a-tricalcium phosphate (TCP) and beta-TCP at 20 = 30.78 degrees/34.21 degrees and 32.47 degrees/33.05 degrees, respectively. The peaks of a-TCP and beta-TCP gradually increased in intensity with the elevation of irradiation energy. In Fourier transforming infrared analysis, two absorption bands at 2200 cm(-1) and 2015 cm(-1) could be traced on dentin treated by Nd:YAG laser with the irradiation energies beyond 150 mJ/pulse-10 pps-4 s. The energy dispersive X-ray results showed that the calcium/phosphorus ratios of the irradiated area proportionally increased with the elevation of irradiation energy. The laser energies of 150 mJ/ pulse-30 pps-4 s and 150 mJ/pulse-20 pps-4 s could result in the a-TCP formation and collagen breakdown. However, the formation of glass-like melted substances without a-TCP at the irradiated site was induced by the energy output of 150 mJ/ pulse-10 pps-4 s. Scanning electron micrographs also revealed that the laser energy of 150 mJ/ pulse-10 pps-4 s was sufficient to prompt melting and recrystallization of dentin crystals without cracking. Therefore, we suggest that the irradiation energy of Nd:YAG laser used to fuse a low melting-point bioactive glass to dentin is 150 m

  2. CO2 laser irradiation on vertical root fracture

    NASA Astrophysics Data System (ADS)

    da Silva, Luciana X.; Aun, Carlos E.; de Campos Ferraz, Jussara

    1997-05-01

    Vertical root fracture has been requested tooth extraction or root hemisection. There is no conservative treatment. The purpose of this paper was to analyze the CO2 laser effects on root fracture, associated with other materials. Forty two extracted human canines divided into 6 groups have their root vertically fractured. In groups A and B the CO2 laser was used with power of 5 W and 7 W respectively and the fracture line was covered with glass ionomer cement. In groups C and D the laser was used with 5 and 7 W and fracture line was covered with a dual composite. Groups E and F were controls, treated with glass ionomer cement and FLC dual composite. The teeth were placed in 5 percent methylene blue dye for 48 hs. The dye penetration was lowest in groups with glass ionomer cement and laser (A and B), at about (1.06mm). The difference between groups was statistically significant at 1 percent. All experimental groups showed dye penetration. The laser seemed to favor the sealing of the fracture line.

  3. Invasion of dentinal tubules by oral bacteria.

    PubMed

    Love, R M; Jenkinson, H F

    2002-01-01

    Bacterial invasion of dentinal tubules commonly occurs when dentin is exposed following a breach in the integrity of the overlying enamel or cementum. Bacterial products diffuse through the dentinal tubule toward the pulp and evoke inflammatory changes in the pulpo-dentin complex. These may eliminate the bacterial insult and block the route of infection. Unchecked, invasion results in pulpitis and pulp necrosis, infection of the root canal system, and periapical disease. While several hundred bacterial species are known to inhabit the oral cavity, a relatively small and select group of bacteria is involved in the invasion of dentinal tubules and subsequent infection of the root canal space. Gram-positive organisms dominate the tubule microflora in both carious and non-carious dentin. The relatively high numbers of obligate anaerobes present-such as Eubacterium spp., Propionibacterium spp., Bifidobacterium spp., Peptostreptococcus micros, and Veillonella spp.-suggest that the environment favors growth of these bacteria. Gram-negative obligate anaerobic rods, e.g., Porphyromonas spp., are less frequently recovered. Streptococci are among the most commonly identified bacteria that invade dentin. Recent evidence suggests that streptococci may recognize components present within dentinal tubules, such as collagen type I, which stimulate bacterial adhesion and intra-tubular growth. Specific interactions of other oral bacteria with invading streptococci may then facilitate the invasion of dentin by select bacterial groupings. An understanding the mechanisms involved in dentinal tubule invasion by bacteria should allow for the development of new control strategies, such as inhibitory compounds incorporated into oral health care products or dental materials, which would assist in the practice of endodontics. PMID:12097359

  4. Scanning ablation of root caries with acoustic feedback control

    NASA Astrophysics Data System (ADS)

    Fan, Kenneth; Fried, Daniel

    2007-02-01

    It has been previously demonstrated that short λ=355-nm laser pulses can be used for the selective removal of caries lesions and composite restorative materials from occlusal surfaces with minimal damage to the peripheral sound tooth structure. One advantage of laser-systems is they can be integrated with acoustic and optical feedback systems for the automated discrimination of dental caries and restorative materials. The objective of this study was to test the hypothesis that root caries could be selectively removed from tooth surfaces using a computer controlled laserscanning system coupled with an acoustic feedback system. Dental root caries surfaces on extracted teeth were scanned with λ=355-nm laser pulses at irradiation intensities ranging from 0.6 to 0.8 J/cm2. Acoustic feedback signals were acquired and used to control the laser output and scanning stages were used to position the laser over carious dentin until all the caries were removed to a fixed depth. Polarization optical coherence tomography (PSOCT) was used to acquire images of the root caries lesions before and after removal by the laser in order to assess if ablation was selective. The amplitude of the acoustic waves generated during the ablation of carious dentin was higher than for sound dentin allowing the acoustic feedback system to discriminate between sound and carious dentin. PS-OCT showed that caries were removed to a depth of up to 1.5-mm with minimal peripheral damage to peripheral sound dentin. The acoustic feedback was successfully used to distinguish between root caries and sound dentin, enabling the selective removal of caries from dentin surfaces using a λ=355-nm, Nd:YAG Q-switched laser system.

  5. In-vitro evaluation of adhesion to human dentine of different canal sealers after Er:YAG laser application

    NASA Astrophysics Data System (ADS)

    Sousa-Neto, Manoel D.; Marchesan, Melissa A.; Pecora, Jesus D.; Brugnera, Aldo, Jr.; Silva-Sousa, Yara T.; Saquy, Paulo C.

    2000-03-01

    Adhesion of endodontic sealers to root canal walls is a property material must have to promote a hermetic seal of the root canal. The present study evaluates the effect of Er:YAG laser applied to human dentine in vitro on adhesion of Grossman, Endomethasone, N-Rickert and Sealer 26 root canal sealers. The crowns of 40 human molars were cut on the occlusal side until a flat dentine surface was obtained. The teeth were divided into 2 groups: group 1, saline solution; group 2, irradiation with Er:YAG laser (KaVo Key Laser 2; 11 mm focal distance, perpendicular to the dentine surface, 4 Hz frequency, 200 mJ energy, 62 J total energy and 313 pulses, one minute application time and 2.25 W power). Five repetitions were done for each sealer and each group. An Instron universal testing machine was used for the adhesion test.The results showed a statistically significant difference at 1% for the sealers and the dentine surface treatments. Sealer 26 showed the best adhesion both with laser application and saline. Application of Er:YAG laser did not alter the adhesion of Grossman, N-Rickert or Endomethasone sealers compared to saline; however, laser application increased the adhesion of Sealer 26.

  6. Effect of gamma irradiation on the antimicrobial and free radical scavenging activities of Glycyrrhiza glabra root

    NASA Astrophysics Data System (ADS)

    Fatima Khattak, Khanzadi; James Simpson, Thomas

    2010-04-01

    The efficacy of gamma irradiation as a method of decontamination for food and herbal materials is well established. In the present study, Glycyrrhiza glabra roots were irradiated at doses 5, 10, 15, 20 and 25 kGy in a cobalt-60 irradiator. The irradiated and un-irradiated control samples were evaluated for phenolic contents, antimicrobial activities and DPPH scavenging properties. The result of the present study showed that radiation treatment up to 20 kGy does not affect the antifungal and antibacterial activity of the plant. While sample irradiated at 25 kGy does showed changes in the antibacterial activity against some selected pathogens. No significant differences in the phenolic contents were observed for control and samples irradiated at 5, 10 and 15 kGy radiation doses. However, phenolic contents increased in samples treated with 20 and 25 kGy doses. The DPPH scavenging activity significantly ( p<0.05) increased in all irradiated samples of the plant.

  7. Dentine in a capsule: clinical case reports.

    PubMed

    Kenchappa, Mallikarjuna; Gupta, Shilpi; Gupta, Puneet; Sharma, Priyamvada

    2015-01-01

    Biodentine TM , a calcium silicate based material has been popular now and can be used as an alternative to mineral trioxide aggregate (MTA) due to superior physical and biologic properties. It has been known by several terms as Biodentine, dentin substitute, and RD 94. It has varied clinical applications such as apexification, apexogenesis, pulpotomy, internal resorption, root perforation repair, retrograde filling, pulp capping procedure, and dentin replacement. This article describes the clinical case reports using Biodentine in apexification, apexogenesis, pulpotomy, and root perforation repair. PMID:26156282

  8. Comparing irradiation parameters on disinfecting enterrecoccus faecalis in root canal disinfection

    NASA Astrophysics Data System (ADS)

    Sarp, Ayşe. S.; Gülsoy, Murat

    2016-02-01

    Although conventional method carries all the debris, studies on persisting infections in root canals show bacteria and their toxins spread from the root canal and contaminate the apical region. Thus developes apical periodontitis or symptoms, and loss of tooth. Even if the treatment has adequate success, anatomy of root canal system can be very complexwith accessory canals. The disinfecting effect of laser radiation has only recently been used in dentistry. Laser irradiation has a bactericidal effect. Each wavelength has its own advantages and limitations according to their different absorption characteristics, depending on their 'absorption coefficient'. The sterilizing efficiency of two types of wavelengths, a new fiber laser 1940- nm Thulium fiber Laser and an 2940 nm Er:YAG Laser were compared in this study. Irradiation with a power of 0.50 W with 1940- nm Thulium fiber Laser disinfected 95,15% of bacteria, however irradiation with same laser power with Er:YAG Laser caused a reduction of 96,48 %. But there was no significant difference in the disinfection effect of two different laser groups ( p < 0.05, Mann- U-Whitney Test). In addition to this, Er :YAG Laser caused three times more reduction from its own positive control group where 1940- nm Thulium fiber Laser caused 2,5 times effective disinfection.

  9. Comparison of tensile bond strengths of four one-bottle self-etching adhesive systems with Er:YAG laser-irradiated dentin.

    PubMed

    Jiang, Qianzhou; Chen, Minle; Ding, Jiangfeng

    2013-12-01

    This study aimed to investigate the interaction of current one-bottle self-etching adhesives and Er:YAG laser with dentin using a tensile bond strength (TBS) test and scanning electron microscopy (SEM) in vitro. Two hundred and thirteen dentin discs were randomly distributed to the Control Group using bur cutting and to the Laser Group using an Er:YAG laser (200 mJ, VSP, 20 Hz). The following adhesives were investigated: one two-step total-etch adhesive [Prime & Bond NT (Dentsply)] and four one-step self-etch adhesives [G-Bond plus (GC), XENO V (Dentsply), iBond Self Etch (Heraeus) and Adper Easy One (3 M ESPE)]. Samples were restored with composite resin, and after 24-hour storage in distilled water, subjected to the TBS test. For morphological analysis, 12 dentin specimens were prepared for SEM. No significant differences were found between the control group and laser group (p = 0.899); dentin subjected to Prime & Bond NT, XENOV and Adper Easy One produced higher TBS. In conclusion, this study indicates that Er:YAG laser-prepared dentin can perform as well as bur on TBS, and some of the one-step one-bottle adhesives are comparable to the total-etch adhesives in TBS on dentin. PMID:24190486

  10. Permeability of Dentine

    PubMed Central

    Ghazali, Farid Bin Che

    2003-01-01

    This is an update on the present integrated knowledge regarding dentine permeability that assumed a role in dentine sensitivity and contribute clinically to the effective bonding properties of restorative dental materials. This paper will attempt to refer to in vivo and in vitro studies of dentine permeability and the various interrelated factors governing it. PMID:23365497

  11. Comparative Morphologic Evaluation and Occluding Effectiveness of Nd: YAG, CO2 and Diode Lasers on Exposed Human Dentinal Tubules: An Invitro SEM Study

    PubMed Central

    Grover, Harpreet Singh; Choudhary, Pankaj

    2016-01-01

    Introduction Dentinal hypersensitivity is one of the most common problem, encountered in dental practice but has least predictable treatment outcome. The advent of lasers in dentistry has provided an additional therapeutic option for treating dentinal hypersensitivity. Although various lasers have been tried over a period of time to treat dentinal hypersensitivity, but still the doubt persist as to which laser leads to maximum dentinal tubular occlusion and is most suitable with minimal hazardous effects. Aim To compare the effects of Nd: YAG, CO2 and 810-nm diode lasers on width of exposed dentinal tubule orifices and to evaluate the morphologic changes on dentinal surface of human tooth after laser irradiation by scanning electron microscope (SEM). Materials and Methods Forty root specimens were obtained from ten freshly extracted human premolars, which were randomly divided into four groups of ten each. Group I: control group treated with only saline, Group II: Nd:YAG laser, Group III: CO2 laser and Group IV: 810-nm diode laser. The specimens were examined using SEM. After calculating mean tubular diameter for each group, the values were compared statistically using parametric one-way ANOVA test and Turkey’s post hoc multiple comparison test. Results All the three lased groups showed a highly statistical significant result with p-value of <0.001 as compared to non-lased group. On intergroup comparison within the lased groups, all the three groups showed statistically significant difference in the reduction of dentinal tubular diameter (p-value < 0.001). Conclusion Nd: YAG laser was found to be most effective, followed by the CO2 laser and 810-nm diode laser was found to be least effective. The morphologic changes like craters, cracks and charring effect of the dentine were seen maximum by the use of CO2 laser.

  12. A histochemical study of the regeneration process after injury by pulsed Nd:YAG laser irradiation of root canals.

    PubMed

    Murakami, Yoshiko; Unno, Arine; Kimura, Yuichi; Okano, Tomohiro; Hossain, Mozammal; Nakamura, Yukio; Matsumoto, Koukichi

    2002-01-01

    Histological changes of rat dental pulp cells were followed after injury. The regeneration process after 3, 6 and 10 days was monitored. Mandibular incisors were irradiated with a pulsed Nd:YAG laser at 2 W and 20 pulses per sec (pps) for 5 sec and the pulp was examined histologically and immunohistochemically for TGF-beta1. Eruption of the developing tooth was disturbed for a short period only. Rapid formation of osteodentin was observed. After 3 days, a zone of fibrodentin matrix as well as newly formed vessels were found. Afterwards, regenerative dentin formation was observed accompanied by the formation of a layer of odontoblast-like cells in the damaged area. Immunohistochemical staining of TGF-beta1 showed that positivity was present in small tissue areas beneath the mantle dentin, the zone of fibrodentin matrix and odontoblast-like cells. These results indicate that pulsed Nd:YAG laser irradiation of rat incisor pulp induces formation of osteodentin, and TGF-beta1 plays a role during regeneration. PMID:12086333

  13. Antimicrobial effect of Er:YAG laser irradiation in infected root canals: an in vitro study

    NASA Astrophysics Data System (ADS)

    Sampaio Moura, Marcelo; Zanin, Fatima A. A.; Brugnera, Aldo, Jr.; Rodrigues de Araujo Estrela, Cyntia; Estrela, Carlos; Djalma Pecora, Jesus

    2003-06-01

    This study evaluated in vitro the antimicrobial action of Er:YAG laser in infected root canals. A total of 36 human anterior teeth were prepared, sterilized and inoculated with suspensions of S. aureus, E. faecalis, P aeruginosa, B. subtilis and C. albicans. After the contamination period (28 days), the teeth were irrigated with sterile distilled water or 1% sodium hypochlorite and, then, irradiated with an Er:YAG laser (wavelength 2094 nm) with two different evaluation parameters: 52 mJ and 110 mJ laser output at the fiber tip. After the irradiation, the teeth were irrigated with sterile distilled water and the solutions were collected with sterile paper points and incubated in Letheen Broth for 48 hours. After this period 0,1 ml of this solution was transferred to 10 ml of Brain Heart Infusion and incubated for 48 hours. After 72 hours a new collect ion was done and incubated again. Based on the data, it was concluded that the distilled water or 1% sodium hypochlorite irradiated or not with an Er:YAG laser with two different parameters: 10 Hz, 110 mJ input and 52 mJ output, and 10 Hz, 250 mJ input and 110 mJ output had no antimicrobial activity in the root canals contaminated with the following microorganisms: Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis and Candida albicans.

  14. Induction of micronuclei in germinating onion seed root tip cells irradiated with high energy heavy ions.

    PubMed

    Takatsuji, Toshihiro; Takayanagi, Hiroki; Morishita, Kana; Nojima, Kumie; Furusawa, Yoshiya; Nakazawa, Yuka; Matsuse, Michiko; Akamatsu, Sakura; Hirano, Natsuko; Hirashima, Natsuko; Hotokezaka, Saori; Ijichi, Toyomi; Kakimoto, Chika; Kanemaru, Tomomi; Koshitake, Mayumi; Moriuchi, Akiko; Yamamoto, Kensuke; Yoshikawa, Isao

    2010-01-01

    Effects of high LET charged particles on a perfect in-vivo system are an essential theme for the study of the biological effects of radiation. Germinating onion seeds are independent complete organisms and the radiation induced micronuclei in the root chip cells can be examined quantitatively and theoretically. We irradiated with three types of high energy accelerated heavy ions germinating onion seeds using a synchrotron and observed micronuclei in the root tip cells. Micronuclei induction showed characteristic dose responses of an upward convex bell shape and a steep rise near zero doses for all types of the ions. The bell curve dose responses, however, could be explained by a simple mathematical model. A parameter in the model which indicates micronuclei induction frequency and another parameter which indicates induction frequency of lethal damages (or damages delaying cell divisions) per heavy ion track were both proportional to square of the LET. Because we suspected by-stander effect concerning the dose responses rising steeply near zero doses and tapering off for higher doses, we tested acute irradiation to remove time of information transmittance between cells using a single spill (about 0.3 s) of the synchrotron beam. No difference was detected between normal multiple spill irradiations and single spill. PMID:20505265

  15. Evaluation of absorbed dose in irradiated sugar-containing plant material (peony roots) by an ESR method

    NASA Astrophysics Data System (ADS)

    Yamaoki, Rumi; Kimura, Shojiro; Ohta, Masatoshi

    2015-12-01

    The relationship between electron spin resonance (ESR) signal intensity of irradiated plant materials and sugar content was investigated by spectral analysis using peony roots. A weak background signal near g=2.005 was observed in the roots. After a 10 kGy irradiation, the ESR line broadened and the intensity increased, and the spectral characteristics were similar to a typical spectrum of irradiated food containing crystalline sugars. The free radical concentration was nearly stable 30 days after irradiation. The spectrum of peony root 30 days after irradiation was simulated using the summation of the intensities of six assumed components: radical signals derived from (a) sucrose, (b) glucose, (c) fructose, (d) cellulose, (e) the background signal near g=2.005 and (f) unidentified component. The simulated spectra using the six components were in agreement with the observed sample spectra. The intensity of sucrose radical signal in irradiated samples increased proportionally up to 20 kGy. In addition, the intensity of sucrose radical signals was strongly correlated with the sucrose contents of the samples. The results showed that the radiation sensitivity of sucrose in peony roots was influenced little by other plant constituents. There was also a good correlation between the total area of the spectra and the sucrose content, because the sucrose content was higher than that of other sugars in the samples. In peony roots, estimation of the absorbed dose from the ESR signal intensity may be possible by a calibration method based on the sucrose content.

  16. Comparison of Push-out Bond Strength of Gutta-percha to Root Canal Dentin in Single-cone and Cold Lateral Compaction Techniques with AH Plus Sealer in Mandibular Premolars.

    PubMed

    Mokhtari, Hadi; Rahimi, Saeed; Forough Reyhani, Mohammad; Galledar, Saeedeh; Mokhtari Zonouzi, Hamid Reza

    2015-01-01

    Background and aims. The single-cone technique has gained some popularity in some European countries. The aim of the present study was to compare the push-out bond strength of gutta-percha to root canal dentin with the single-cone and cold lateral compaction canal obturation techniques. Materials and methods . The root canals of 58 human mandibular premolars were prepared using modified crown-down technique with ProTaper rotary files up to #F3as a master apical file (MAF) and divided randomly into groups A and B based on canal obturation technique. In group A (n = 29) the root canals were obturated with single-cone technique with #F3(30/.09) ProTaper gutta-percha, which was matched with MAF in relation to diameter, taper and manufacturer; in group B (n = 29) the canals were obturated with gutta-percha using cold lateral compaction technique. In both groups AH plus sealer were used. After two weeks of incubation, three 2-mm slices were prepared at a distance of 2 mm from the coronal surface and push-out test was carried out. Data were analyzed with descriptive statistics using independent samples t-test. Results. There were statistically significant differences between two groups. The mean push-out bond strength was higher in group B (lateral compaction technique) compared to group A (single-cone technique; P < 0.05). Conclusion . Use of single-cone technique for obturation of root canals resulted in a lower bond strength compared to cold lateral compaction technique. PMID:26889358

  17. Comparison of Push-out Bond Strength of Gutta-percha to Root Canal Dentin in Single-cone and Cold Lateral Compaction Techniques with AH Plus Sealer in Mandibular Premolars

    PubMed Central

    Mokhtari, Hadi; Rahimi, Saeed; Forough Reyhani, Mohammad; Galledar, Saeedeh; Mokhtari Zonouzi, Hamid Reza

    2015-01-01

    Background and aims. The single-cone technique has gained some popularity in some European countries. The aim of the present study was to compare the push-out bond strength of gutta-percha to root canal dentin with the single-cone and cold lateral compaction canal obturation techniques. Materials and methods. The root canals of 58 human mandibular premolars were prepared using modified crown-down technique with ProTaper rotary files up to #F3as a master apical file (MAF) and divided randomly into groups A and B based on canal obturation technique. In group A (n = 29) the root canals were obturated with single-cone technique with #F3(30/.09) ProTaper gutta-percha, which was matched with MAF in relation to diameter, taper and manufacturer; in group B (n = 29) the canals were obturated with gutta-percha using cold lateral compaction technique. In both groups AH plus sealer were used. After two weeks of incubation, three 2-mm slices were prepared at a distance of 2 mm from the coronal surface and push-out test was carried out. Data were analyzed with descriptive statistics using independent samples t-test. Results. There were statistically significant differences between two groups. The mean push-out bond strength was higher in group B (lateral compaction technique) compared to group A (single-cone technique; P < 0.05). Conclusion. Use of single-cone technique for obturation of root canals resulted in a lower bond strength compared to cold lateral compaction technique. PMID:26889358

  18. Adaptation of threaded dowels to dentin.

    PubMed

    Zmener, O

    1980-05-01

    Adaptation of threaded dowels to the walls of the canals is minimal in the cervical third and maximal in the apical third. Each of the three types of dowels may cause lateral stresses and possibly fracture. Matched reamers and dowels reduce the danger of fracture. Smaller-diameter dowels maintain less contact with the dentin and avoid weakening the root. The Kurer Anchor system provided a satisfactory combination of nonlateral residual stresses which protected the root from complications. PMID:6988582

  19. [Root caries--scanning electron microscopic observations].

    PubMed

    Heinrich, R; Hornová, J; Kneist, S; Künzel, W

    1990-01-01

    Sound and carious root surfaces of 24 extracted human teeth with extensive periodontal attachment loss were examined by SEM. The microflora covering the radicular surfaces was a complex flora consisting of filamentous and fusiform bacteria, short and long rods. Cocci and coccoid bacteria were observed on root surfaces. Bacterial invasion in the exposed peripheral root dentin was delayed by sclerotic dentin. PMID:2150459

  20. Mesenchymal Dental Pulp Cells Attenuate Dentin Resorption in Homeostasis

    PubMed Central

    Zheng, Y.; Chen, M.; He, L.; Marão, H.F.; Sun, D.M.; Zhou, J.; Kim, S.G.; Song, S.; Wang, S.L.

    2015-01-01

    Dentin in permanent teeth rarely undergoes resorption in development, homeostasis, or aging, in contrast to bone that undergoes periodic resorption/remodeling. The authors hypothesized that cells in the mesenchymal compartment of dental pulp attenuate osteoclastogenesis. Mononucleated and adherent cells from donor-matched rat dental pulp (dental pulp cells [DPCs]) and alveolar bone (alveolar bone cells [ABCs]) were isolated and separately cocultured with primary rat splenocytes. Primary splenocytes readily aggregated and formed osteoclast-like cells in chemically defined osteoclastogenesis medium with 20 ng/mL of macrophage colony-stimulating factor (M-CSF) and 50 ng/mL of receptor activator of nuclear factor κB ligand (RANKL). Strikingly, DPCs attenuated osteoclastogenesis when cocultured with primary splenocytes, whereas ABCs slightly but significantly promoted osteoclastogenesis. DPCs yielded ~20-fold lower RANKL expression but >2-fold higher osteoprotegerin (OPG) expression than donor-matched ABCs, yielding a RANKL/OPG ratio of 41:1 (ABCs:DPCs). Vitamin D3 significantly promoted RANKL expression in ABCs and OPG in DPCs. In vivo, rat maxillary incisors were atraumatically extracted (without any tooth fractures), followed by retrograde pulpectomy to remove DPCs and immediate replantation into the extraction sockets to allow repopulation of the surgically treated root canal with periodontal and alveolar bone–derived cells. After 8 wk, multiple dentin/root resorption lacunae were present in root dentin with robust RANKL and OPG expression. There were areas of dentin resoprtion alternating with areas of osteodentin formation in root dentin surface in the observed 8 wk. These findings suggest that DPCs of the mesenchymal compartment have an innate ability to attenuate osteoclastogenesis and that this innate ability may be responsible for the absence of dentin resorption in homeostasis. Mesenchymal attenuation of dentin resorption may have implications in internal

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

    PubMed

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

    2016-04-01

    The aim of this study was to evaluate the chemical stability of endodontic-treated root dentin after different laser irradiations through Raman spectroscopy. Fifty maxillary canines were selected and prepared with K3 system. Roots were randomly distributed into five groups (n = 10) according to the surface treatment: GI (water), GII (NaOCl + EDTA), GIII (NaOCl + EDTA + 980 nm Diode laser), GIV (NaOCl + EDTA+ 1064 nm Nd: YAG laser) and GV (NaOCl + EDTA+ 2780 nm Er,Cr: YSGG laser). Lasers were applied for 20 s. Samples were bisected, and the organic and inorganic content of dentin was analyzed by Raman spectroscopy. Data were submitted to ANOVA and Tukey tests (p < 0.05). None of the surface treatments alter the inorganic content (cts) (p = 0.183). Roots irradiated with Er,Cr: YSGG laser had a reduced collagen content (GV-290.7 ± 41.7) compared with the water-treated roots (GI-328.3 ± 63.5) and those treated with NaOCl + EDTA (GII-333.9 ± 55.8). Roots irradiated with Er,Cr: YSGG laser also showed a higher inorganic/organic ratio (GV-9.5 ± 1.1) than roots treated with water (GI-7.7 ± 1.5), NaOCl + EDTA (GII-8.0 ± 1.4) and diode laser (GIII-8.2 ± 1.6). Both organic and inorganic contents increased from cervical to apical thirds in all groups. None of the surface treatments were able to promote changes in the inorganic content of the root dentin; treatment with NaOCl + EDTA combined with Er,Cr: YSGG altered collagen. PMID:26796704

  2. Biomimetic remineralization of dentin

    PubMed Central

    Niu, Li-na; Zhang, Wei; Pashley, David H.; Breschi, Lorenzo; Mao, Jing; Chen, Ji-hua; Tay, Franklin R.

    2013-01-01

    Objectives Remineralization of demineralized dentin is important for improving dentin bonding stability and controlling primary and secondary caries. Nevertheless, conventional dentin remineralization strategy is not suitable for remineralizing completely-demineralized dentin within hybrid layers created by etch-and-rinse and moderately aggressive self-etch adhesive systems, or the superficial part of a caries-affected dentin lesion left behind after minimally invasive caries removal. Biomimetic remineralization represents a different approach to this problem by attempting to backfill the demineralized dentin collagen with liquid-like amorphous calcium phosphate nanoprecursor particles that are stabilized by biomimetic analogs of noncollagenous proteins. Methods This paper reviewed the changing concepts in calcium phosphate mineralization of fibrillar collagen, including the recently discovered, non-classical particle-based crystallization concept, formation of polymer-induced liquid- precursors (PILP), experimental collagen models for mineralization, and the need for using phosphate-containing biomimetic analogs for biomimetic mineralization of collagen. Published work on the remineralization of resin-dentin bonds and artificial caries-like lesions by various research groups was then reviewed. Finally, the problems and progress associated with the translation of a scientifically-sound concept into a clinically-applicable approach are discussed. Results and Significance The particle-based biomimetic remineralization strategy based on the PILP process demonstrates great potential in remineralizing faulty hybrid layers or caries-like dentin. Based on this concept, research in the development of more clinically feasible dentin remineralization strategy, such as incorporating poly(anionic) acid-stabilized amorphous calcium phosphate nanoprecursor-containing mesoporous silica nanofillers in dentin adhesives, may provide a promising strategy for increasing of the

  3. Effects of Citric Acid and Desensitizing Agent Application on Nonfluorosed and Fluorosed Dentin: An In Vitro Sem Study

    PubMed Central

    Neha, Mahajan; Vandana, Laxman K

    2015-01-01

    Fluorosis is one of the factors which bring about mineralisation changes in a dentinal structure leading to dentin. The purpose of the present study was to compare and evaluate the dentinal tubular changes in fluorosed and nonfluorosed teeth subsequent to the application of citric acid,strontium acetate based sodium fluoride (SAF) using scanning electron microscopy (SEM). Dentin specimens from healthy fluorosed and nonfluorosed teeth were included in the study. Each of them was grouped into acid treated and SAF treatment groups. Using SEM, the photomicrographs (3500x) of dentin specimens were evaluated. Results showed while there was a significant difference in tubular width of partial occlusion ≤ 25%, being more in fluorosed group compared to nonfluorosed group after application SAF. Application of desensitising agents demonstrated higher number of dentinal tubular occlusion and diameter reduction in nonfluorosed dentin compared to fluorosed dentin. Summary: Root biomodification and desensitising agent procedure brings in definite difference between fluorosed and non-fluorosed dentin specimens. PMID:25870716

  4. Soluble carbohydrate allocation to roots, photosynthetic rate of leaves, and nitrate assimilation as affected by nitrogen stress and irradiance

    NASA Technical Reports Server (NTRS)

    Henry, L. T.; Raper, C. D. Jr

    1991-01-01

    Upon resupply of exogenous nitrogen to nitrogen-stressed plants, uptake rate of nitrogen is enhanced relative to nonstressed plants. Absorption of nitrogen presumably is dependent on availability of carbohydrates in the roots. A buildup in soluble carbohydrates thus should occur in roots of nitrogen-stressed plants, and upon resupply of exogenous nitrogen the increased uptake rate should be accompanied by a rapid decline in carbohydrates to prestress levels. To evaluate this relationship, three sets of tobacco plants growing in a complete hydroponic solution containing 1.0 mM NO3- were either continued in the complete solution for 21 d, transferred to a minus-nitrogen solution for 21 d, or transferred to a minus-nitrogen solution for 8-9 d and then returned to the 1.0 mM NO3- solution. These nitrogen treatments were imposed upon plants growing at photosynthetic photon flux densities of 700 and 350 micromoles m-2 s-1. Soluble carbohydrate levels in roots increased during onset of nitrogen stress to levels that were fourfold greater than in roots of non-stressed plants. Following resupply of external nitrogen, a rapid resumption of nitrogen uptake was accompanied by a decline in soluble carbohydrates in roots to levels characteristic of nonstressed plants. This pattern of soluble carbohydrate levels in roots during onset of and recovery from nitrogen stress occurred at both irradiance levels. The response of net photosynthetic rate to nitrogen stress could be expressed as a nonlinear function of concentration of reduced nitrogen in leaves. The net photosynthetic rate at a given concentration of reduced nitrogen, however, averaged 10% less at the lower than at the higher irradiance. The decline in net photosynthetic rate per unit of reduced nitrogen in leaves at the lower irradiance was accompanied by an increase in the nitrate fraction of total nitrogen in leaves from 20% at the higher irradiance to 38% at the lower irradiance.

  5. Comprehensive analyses of how tubule occlusion and advanced glycation end-products diminish strength of aged dentin

    PubMed Central

    Shinno, Yuko; Ishimoto, Takuya; Saito, Mitsuru; Uemura, Reo; Arino, Masumi; Marumo, Keishi; Nakano, Takayoshi; Hayashi, Mikako

    2016-01-01

    In clinical dentistry, since fracture is a major cause of tooth loss, better understanding of mechanical properties of teeth structures is important. Dentin, the major hard tissue of teeth, has similar composition to bone. In this study, we investigated the mechanical properties of human dentin not only in terms of mineral density but also using structural and quality parameters as recently accepted in evaluating bone strength. Aged crown and root dentin (age ≥ 40) exhibited significantly lower flexural strength and toughness than young dentin (age < 40). Aged dentin, in which the dentinal tubules were occluded with calcified material, recorded the highest mineral density; but showed significantly lower flexural strength than young dentin. Dentin with strong alignment of the c-axis in hydroxyapatite exhibited high fracture strength, possibly because the aligned apatite along the collagen fibrils may reinforce the intertubular dentin. Aged dentin, showing a high advanced glycation end-products (AGEs) level in its collagen, recorded low flexural strength. We first comprehensively identified significant factors, which affected the inferior mechanical properties of aged dentin. The low mechanical strength of aged dentin is caused by the high mineral density resulting from occlusion of dentinal tubules and accumulation of AGEs in dentin collagen. PMID:26797297

  6. Dentin dysplasia type I – A rare entity

    PubMed Central

    Malik, Sangeeta; Gupta, Swati; Wadhwan, Vijay; Suhasini, GP

    2015-01-01

    Dentin dysplasia is a rare disturbance of dentin formation characterized by normal enamel but atypical dentin formation with abnormal pupal morphology. The teeth appear clinically normal in morphologic appearance and color. The teeth characteristically exhibit extreme mobility and are commonly exfoliated prematurely. Radiograph shows obliteration of all pulp chambers, short, blunted and malformed or absent roots with periapical radiolucencies involving apparently intact tooth. This case is reported here because of its rarity along with the description of various clinical, radiological and histological features. PMID:26097326

  7. Assessment Using AutoCAD Software of the Preparation of Dentin Walls in Root Canals Produced by 4 Different Endodontic Instrument Systems.

    PubMed

    Cabanillas, Cristina; Monterde, Manuel; Pallarés, Antonio; Aranda, Susana; Montes, Raquel

    2015-01-01

    Objectives. To compare the effectiveness of four instrument systems for preparing oval root canals: manual instrumentation (Step-Back technique), ProTaper Universal, ProTaper Next, and Wave One. Material and Methods. For the purpose of this assessment, 60 teeth extracted for orthodontic or periodontal reasons, specifically canines and premolars with full coronal and root anatomy, were used and 15 samples were assigned to each group. The section of the canals was compared before and after instrumenting and the section of untouched canal wall was measured using AutoCAD software. The data was analysed by means of Shapiro-Wilk, ANOVA, and Kruskal-Wallis tests. Results. In the apical third, 100% of the canals were prepared with all the systems. In the middle third, a p value of 0.5989 in the Kruskal-Wallis test was obtained, which indicates no significant difference between the groups. At the coronal third level, the results obtained revealed that Wave One had a significantly lower mean average than the rest (p < 0.05). Conclusions. There are no differences between the various root canal instrument systems in the apical and middle thirds. At the coronal third level, Wave One system showed performance significantly worse than the rest, among which there were no differences. PMID:26664361

  8. Assessment Using AutoCAD Software of the Preparation of Dentin Walls in Root Canals Produced by 4 Different Endodontic Instrument Systems

    PubMed Central

    Cabanillas, Cristina; Monterde, Manuel; Pallarés, Antonio; Aranda, Susana; Montes, Raquel

    2015-01-01

    Objectives. To compare the effectiveness of four instrument systems for preparing oval root canals: manual instrumentation (Step-Back technique), ProTaper Universal, ProTaper Next, and Wave One. Material and Methods. For the purpose of this assessment, 60 teeth extracted for orthodontic or periodontal reasons, specifically canines and premolars with full coronal and root anatomy, were used and 15 samples were assigned to each group. The section of the canals was compared before and after instrumenting and the section of untouched canal wall was measured using AutoCAD software. The data was analysed by means of Shapiro-Wilk, ANOVA, and Kruskal-Wallis tests. Results. In the apical third, 100% of the canals were prepared with all the systems. In the middle third, a p value of 0.5989 in the Kruskal-Wallis test was obtained, which indicates no significant difference between the groups. At the coronal third level, the results obtained revealed that Wave One had a significantly lower mean average than the rest (p < 0.05). Conclusions. There are no differences between the various root canal instrument systems in the apical and middle thirds. At the coronal third level, Wave One system showed performance significantly worse than the rest, among which there were no differences. PMID:26664361

  9. Intrapulpal temperature changes during root surface irradiation with dual-wavelength laser (2780 and 940 nm): in vitro study

    NASA Astrophysics Data System (ADS)

    Franzen, Rene; Rashidisangsary, Borna; Ozturan, Seda; Vanweersch, Leon; Gutknecht, Norbert

    2015-01-01

    The present study evaluated the intrapulpal thermal changes that occurred during the treatment of the root surfaces with a laser system emitting Er,Cr:YSGG 2780- and 940-nm diode laser irradiation in an alternating sequence. Thirty single-rooted human teeth were collected. The teeth were divided into three groups (n=10 each) and irradiated with Er,Cr:YSGG alone or combined with a 940-nm diode laser. To investigate the intrapulpal temperature changes, specimens were embedded in a resin block with a set of thermocouples introduced at different positions within the root canals. The first group was irradiated with only Er,Cr:YSGG (25 mJ, 50 Hz, 50 μs pulse duration, water and air spray); the second group was irradiated with Er,Cr:YSGG (same setting) and a 940-nm diode (2 W, chopped mode with 20% duty cycle); the third group was irradiated with Er,Cr:YSGG (same setting) and a diode (2 W, chopped mode with 50% duty cycle). During all irradiations, thermal changes were recorded in real time with thermocouples. While group 3 showed thermal rises on average of 1.68±0.98°C in the pulp chamber, groups 1 and 2 showed average temperature rises of <0.5°C. The combined laser emission of 2780 and 940 nm is a promising way for root surface debridement without inducing intrapulpal thermal damage when using an appropriate water/air spray. All measured temperatures were considerably below the critical value of 5.6°C.

  10. Exposure to ginger root oil enhances mating success of irradiated, mass-reared males of Mediterranean fruit fly (Diptera: Tephritidae).

    PubMed

    Shelly, T E; McInnis, D O

    2001-12-01

    Previous research revealed that exposure to ginger root oil, Zingiber officinale Roscoe, containing the known male attractant (a-copaene) increased the mating success of male Mediterranean fruit flies, Ceratitis capitata (Wiedemann), from a newly established laboratory colony. The goal of the current study was to determine whether exposure to ginger root oil likewise enhanced the mating competitiveness of irradiated C. capitata males from a 5-yr-old mass-reared strain. Mating tests were conducted in field cages containing guava trees (Psidium guajava L.) to monitor the mating frequency of irradiated, mass-reared and wild males competing for wild females. In the absence of chemical exposure, wild males outcompeted the mass-reared males and obtained 74% of all matings. However, following exposure to ginger root oil (20 microl for 6 h), the mating frequencies were reversed. Whether exposed as mature (3-d-old) or immature (1-d-old) adults, mass-reared males achieved approximately 75% of all matings in tests conducted 2 or 4 d following exposure, respectively. Irradiated, mass-reared males prevented from contacting the oil directly (i.e., exposed to the odor only for 6 h) still exhibited a mating advantage over wild males. In an additional study, signaling levels and female arrivals were compared between males exposed to ginger root oil and nonexposed males, but no significant differences were detected. The implications of these findings for the sterile insect technique are discussed. PMID:11777043

  11. Residual Dentin Thickness of Bifurcated Maxillary Premolars Following Two Post Space Preparation Methods

    PubMed Central

    Ghoddusi, Jamileh; Bagherpour, Ali; Mahmudabadi, Fatemeh; Forghani, Maryam; Sarmad, Majid

    2013-01-01

    Introduction The aim of this in vitro study was to compare the effect of Gates-Glidden and Peeso reamer drills on residual dentin thickness during post space preparation in order to discover which method has minimum root structure damage. Materials and Methods Thirty extracted human maxillary premolars with bifurcations at root middle were horizontally cut 15 mm coronal to the apical end after root canal treatment. The samples were scannedby Cone Beam Computed Tomography (CBCT) before and after preparing the post space. Residual dentin thicknesses were measured at 4-, 6-, and 8-mm levels from the apex. Data were analyzed using repeated measured ANOVA. Results Endodontic therapy and post space preparations removed more dentin within the bifurcation of both roots compared to outer dentin. The difference in residual dentin thickness was highly significant regarding stage (before and after post space preparation) in all levels and stage × device in coronal and middle levels (P<.05). This in vitro study emphasizes the minimal dentin width in the buccal root of maxillary premolars, especially near the bifurcation. Conclusion Lack of adequate residual dentin thickness after post space preparation implies that the use of posts in maxillary first premolars should be limited. When mandatory, it is recommended that post space be prepared with Gates-Glidden drill in the palatal root of maxillary first premolars and use of Peeso reamer be avoided. PMID:23922568

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

    PubMed Central

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

    2013-01-01

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

  13. Dentin Dysplasia in Notum Knockout Mice.

    PubMed

    Vogel, P; Read, R W; Hansen, G M; Powell, D R; Kantaputra, P N; Zambrowicz, B; Brommage, R

    2016-07-01

    Secreted WNT proteins control cell differentiation and proliferation in many tissues, and NOTUM is a secreted enzyme that modulates WNT morphogens by removing a palmitoleoylate moiety that is essential for their activity. To better understand the role this enzyme in development, the authors produced NOTUM-deficient mice by targeted insertional disruption of the Notum gene. The authors discovered a critical role for NOTUM in dentin morphogenesis suggesting that increased WNT activity can disrupt odontoblast differentiation and orientation in both incisor and molar teeth. Although molars in Notum(-/-) mice had normal-shaped crowns and normal mantle dentin, the defective crown dentin resulted in enamel prone to fracture during mastication and made teeth more susceptible to endodontal inflammation and necrosis. The dentin dysplasia and short roots contributed to tooth hypermobility and to the spread of periodontal inflammation, which often progressed to periapical abscess formation. The additional incidental finding of renal agenesis in some Notum (-/-) mice indicated that NOTUM also has a role in kidney development, with undiagnosed bilateral renal agenesis most likely responsible for the observed decreased perinatal viability of Notum(-/-) mice. The findings support a significant role for NOTUM in modulating WNT signaling pathways that have pleiotropic effects on tooth and kidney development. PMID:26926082

  14. Microbial contamination of the environment after the irradiation of Er:YAG laser in infected root canals

    NASA Astrophysics Data System (ADS)

    Brugnera, Aldo, Jr.; Zanin, Fatima A. A.; Sampaio Moura, Marcelo; Heredia Seixas, Fabio; Rodrigues de Araujo Estrela, Cyntia; Estrela, Carlos; Djalma Pecora, Jesus

    2003-06-01

    The purpose of this study was to analyze the environment microbial contamination produced by Er:YAG laser irradiation in infected root canals. A total of 20 human anterior teeth were prepared, sterilized and, then, inoculated with a mixture of the following microorganisms: S. Aureus, E. Faecalis, P. Aeruginosa, B. Subtilis and C. Albicans. After the contamination period (28 days), the teeth were irrigated with sterile distilled water or 1% sodium hypochlorite and, then, irradiated with an Er:YAG laser with two different laser parameters: 52 mJ or 110 mJ output at the fiber tip. Eighteen Petri dishes with 20 ml of BHI Agar were used in the study. For each group, 3 plates with BHIA were used for the analysis of the microbial contamination of the environment during the activation of the laser in infected root canals. The plates were positioned in differing distances away from the irradiated tooth (plate 1 - distance of 15 cm, plate 2 - distance of 50 cm and plate 3 - distance of 3 meters). After the analysis of the results, it was observed that the larger microbial contamination occurred in Group 1 (teeth irrigated with sterile distilled water and irradiated with Er:YAG laser with 52 mJ output at the fiber tip), plate 1 (positioned 15 cm away from the irradiated tooth), with values greater than 30 Colony-Forming Units (CFU).

  15. Root canal preparation with Er:YSGG laser

    NASA Astrophysics Data System (ADS)

    Benthin, Hartmut; Ertl, Thomas P.; Onal, B.; Schruender, Stephan; Mueller, Gerhard J.

    1994-12-01

    The high level of efficiency of hard tissue ablation with Er:YAG and Er:YSGG lasers is well known. Of these lasers it is possible only to transmit Er:YSGG laser radiation with OH reduced quartz fibers. Most of the fibers we use in this study were prepared as hemispherical fiber tips. Fifty single rooted teeth were divided into ten groups (n equals 5). After conventional opening of the pulp chamber, root canal preparation was performed in five groups under water only using the laser. In the other five groups preparation with K-files to size 35 was performed before treatment with laser radiation. All teeth were axially separated with direct access to the root canal and examined in SEM investigations. The groups were compared by measuring the areas with patent dentin tubules. Representative areas were examined by TEM. The temperature at the root surface was measured during laser irradiation with thermocouples positioned at several points. The in-vitro study of the effect of the high delivered energy (50 - 100 mJ per pulse) in the root canal showed a good ablation effect. Most of the dentin tubules were opened. The increase in temperature at the root surface was tolerable.

  16. Effects of Er:YAG and Nd:YAG laser irradiation on the permeability of instrumented root canal walls

    NASA Astrophysics Data System (ADS)

    Brugnera, Aldo, Jr.; Zanin, Fatima A. A.; Barbin, Eduardo L.; Emboava Spano, Julio C.; Santana da Silva, Reginaldo; Pecora, Jesus D.

    2002-06-01

    The aim of this study was to evaluate the effect of Er:YAG and Nd:YAG laser on radicular dentine permeability when using distilled and deionized water and 1% sodium hypochlorite as irrigating solutions. Thirty human maxillary canines obtained from laboratory stock and conserved in 0.1% thymol until use were divided randomly into six groups of five teeth each. The root canals were instrumented with K files and the step-back technique. The surgical diameter was achieved 4 files above the original anatomical diameter. Group I, the teeth were irrigated with distilled and deionized water; Group II, the teeth were irrigated with 1% sodium hypochlorite, Group II the teeth were irrigated with distilled and deionized water and then Er:YAG laser was applied with 140mJ, 15Hz, 300 pulses and 42J; group 4 the teeth were irrigated with 1% sodium hypochlorite and Er:YAG laser was applied in the same parameters as Group III, Group V, the teeth received irrigation with distilled and deionized water and Nd:YAG laser application with 150mJ, 15Hz, 2,25W and Group VI the teeth were irrigated with 1% sodium hypochlorite and Nd:YAG laser was applied with the same parameters as Group V. During laser application the teeth were always filled with irrigating solution. The fiber optic tip was introduced until the apex and the laser was activated. The tip was withdrawn gently with helicoidally movement from the apex until the pulp chamber. After preparation the teeth were immersed in 10% copper sulfate for 30 minutes, in vacuum for the first 5 minutes. The teeth were then placed in a 1% rubianic acid alcohol solution for the same periodsin solution and in vacuum as above. Upon completion of this reaction the teeth were sectioned transversally, in 150micrometers slices, and sanded, washed, dehydrated, cleared and mounted on glass slides for microscopic examination. The quantification of the penetration of copper ions was done by morphmetric analysis with a 400-point grid. The data was submitted

  17. Penetration of smeared or nonsmeared dentine by Streptococcus gordonii.

    PubMed

    Love, R M; Chandler, N P; Jenkinson, H F

    1996-01-01

    The purpose of this study was to investigate the penetration of smeared and nonsmeared dentine by Streptococcus gordonii. Prepared human roots, grouped as either nonsmeared or smeared, were immersed in a suspension of S. gordonii cells for 3 weeks. The roots were then prepared for scanning electron microscopy and histological analysis. Dentine discs prepared from coronal dentine were grouped similarly. Using a fluid filtration apparatus, the hydraulic conductance (Lp) of each disc was determined before and after incubation with bacterial suspension. Scanning electron microscopy evaluation of the roots following infection with bacteria showed no change in the smear layer (P < 0.0001). Histological sections revealed that bacterial penetration of all the nonsmeared samples had occurred, while nine out of 10 smeared samples showed no bacterial penetration (P < 0.0001). The Lp of the nonsmeared discs was significantly reduced by 42% (P < 0.0001) after bacterial penetration. However, the smeared samples revealed a 1% reduction in Lp which was not significant (P > 0.05). The results suggest that dentinal smear layers are an effective barrier to dentinal tubule invasion by S. gordonii. PMID:9206406

  18. Porcine Dentin Sialophosphoprotein

    PubMed Central

    Yamakoshi, Yasuo; Lu, Yuhe; Hu, Jan C.-C.; Kim, Jung-Wook; Iwata, Takanori; Kobayashi, Kazuyuki; Nagano, Takatoshi; Yamakoshi, Fumiko; Hu, Yuanyuan; Fukae, Makoto; Simmer, James P.

    2008-01-01

    Dentin sialophosphoprotein (DSPP) is critical for proper mineralization of tooth dentin, and mutations in DSPP cause inherited dentin defects. Dentin phosphoprotein (DPP) is the C-terminal cleavage product of DSPP that binds collagen and induces intrafibrillar mineralization. We isolated DPP from individual pigs and determined that its N-terminal and C-terminal domains are glycosylated and that DPP averages 155 phosphates per molecule. Porcine DPP is unstable at low pH and high temperatures, and complexing with collagen improves its stability. Surprisingly, we observed DPP size variations on SDS-PAGE for DPP isolated from individual pigs. These variations are not caused by differences in proteolytic processing or degrees of phosphorylation or glycosylation, but rather to allelic variations in Dspp. Characterization of the DPP coding region identified 4 allelic variants. Among the 4 alleles, 27 sequence variations were identified, including 16 length polymorphisms ranging from 3 to 63 nucleotides. None of the length variations shifted the reading frame, and all localized to the highly redundant region of the DPP code. The 4 alleles encode DPP domains having 551, 575, 589, or 594 amino acids and completely explain the DPP size variations. DPP length variations are polymorphic and are not associated with dentin defects. PMID:18359767

  19. Irradiation effects on color and functional properties of persimmon ( Diospyros kaki L. folium) leaf extract and licorice ( Glycyrrhiza Uralensis Fischer) root extract during storage

    NASA Astrophysics Data System (ADS)

    Jo, Cheorun; Son, Jun Ho; Shin, Myung Gon; Byun, Myung Woo

    2003-06-01

    Irradiation effects on color and functional properties of persimmon ( Diospyros kaki L. folium) leaf extract and licorice ( Glycyrrhiza Uralensis Fischer) root extract were studied. Persimmon leaf and licorice root extracts were irradiated using 60Co gamma irradiator at 0 and 20 kGy absorbed dose and stored at 4°C or -20°C for 2 weeks. Tyrosinase inhibition effect (TIE) of both extracts was not different by 20 kGy-irradiation but reduced during storage. Electron donating ability (EDA) of the persimmon leaf extract was generally consistent, but that of licorice root extract was reduced by irradiation except for 1 week of storage. Both TIE and EDA of persimmon leaf extract were higher than that of licorice root. Hunter color L*-, a*-, and b*-values were changed, resulting in a desirable brighter color by irradiation. During storage, the bright yellow color of irradiated sample changed to brown gradually, and especially the changes in the refrigeration condition (4°C) was faster than frozen (-20°C). Results indicate that irradiation can be a useful method to produce value-added natural ingredients with functions such as persimmon leaf or licorice root for food or cosmetic industry in addition to elimination of microbial load.

  20. Evaluation of the antimicrobial effect of Er:YAG laser irradiation versus 1% sodium hypochlorite irrigation for root canal disinfection.

    PubMed

    Perin, Fernanda M; França, Suzelei C; Silva-Sousa, Yara T C; Alfredo, Edson; Saquy, Paulo C; Estrela, Carlos; Sousa-Neto, Manoel D

    2004-04-01

    This laboratory study evaluated Er:YAG laser antibacterial action in infected root canals. Forty-eight maxillary central incisors were used. After canal preparation, the teeth were autoclaved and divided into four groups: (1) non-treated teeth (control group); (2) teeth treated with NaOCl; (3) teeth irradiated with Er:YAG laser (7 Hz, 100 mJ, 80 pulses/canal, 11 sec) to the working length; (4) teeth irradiated similarly to, but 3 mm short, of the apex. The root canals from Groups 2, 3 and 4 were inoculated with 4 bacteria: Bacillus subtillus, Enterococcus faecalis, Pseudomonas aeruginosa, and Staphylococcus aureus, together with Candida albicans, and maintained for 24 h at 37 degrees C. All suspensions were adjusted to tube 2 of the MacFarland scale. The intracanal material was then collected with sterile paper points, which were placed in the canals for 5 min and then immersed in 5 ml of BHI medium. This was then seeded onto agar and stained by Gram's method. The NaOCl solutions and the Er:YAG laser irradiation to working length were effective against all five micro-organisms; however, 70% of the specimens irradiated 3 mm short of the apex remained infected. PMID:15116905

  1. Resistance of dentin coating materials against abrasion by toothbrush.

    PubMed

    Gando, Iori; Ariyoshi, Meu; Ikeda, Masaomi; Sadr, Alireza; Nikaido, Toru; Tagami, Junji

    2013-01-01

    Thin-film coating of root dentin surface by all-in-one adhesives has been shown to be an effective option to prevent root surface caries. The purpose of this study was to investigate the wear resistance against toothbrush abrasion of two all-in-one coating materials; Shield Force (SF) and Hybrid Coat (HC). Bovine dentin surfaces were covered with one of the coating materials; SF or HC. After storage in water for 24 h, the testing surface was subjected to the toothbrush abrasion test up to 50,000 cycles either in water or toothpaste slurry. The remaining thickness of the coating material was measured using SEM. Toothpaste slurry significantly increased rate of tooth brush abrasion of the coating materials. While SF and HC wore at a similar pace under toothbrush abrasion, SF had a thicker coat and could protect dentin longer, up to 50,000 cycles. PMID:23370872

  2. Pulp and dentin tissue engineering and regeneration: current progress

    PubMed Central

    Huang, George TJ

    2009-01-01

    Dental pulp tissue is vulnerable to infection. Entire pulp amputation followed by pulp-space disinfection and filling with an artificial rubber-like material is employed to treat the infection – commonly known as root-canal therapy. Regeneration of pulp tissue has been difficult as the tissue is encased in dentin without collateral blood supply except from the root apical end. However, with the advent of the concept of modern tissue engineering and the discovery of dental stem cells, regeneration of pulp and dentin has been tested. This article will review the early attempts to regenerate pulp tissue and the current endeavor of pulp and dentin tissue engineering, and regeneration. The prospective outcome of the current advancement in this line of research will be discussed. PMID:19761395

  3. Pulp and dentin tissue engineering and regeneration: current progress.

    PubMed

    Huang, George T J

    2009-09-01

    Dental pulp tissue is vulnerable to infection. Entire pulp amputation followed by pulp-space disinfection and filling with an artificial rubber-like material is employed to treat the infection - commonly known as root-canal therapy. Regeneration of pulp tissue has been difficult as the tissue is encased in dentin without collateral blood supply except from the root apical end. However, with the advent of the concept of modern tissue engineering and the discovery of dental stem cells, regeneration of pulp and dentin has been tested. This article will review the early attempts to regenerate pulp tissue and the current endeavor of pulp and dentin tissue engineering, and regeneration. The prospective outcome of the current advancement in this line of research will be discussed. PMID:19761395

  4. CO2 laser and fluoride on the inhibition of root caries—an in vitro microbial model

    NASA Astrophysics Data System (ADS)

    Steiner-Oliveira, C.; Rodrigues, L. K. A.; Parisotto, T. M.; Sousa E Silva, C. M.; Hara, A. T.; Nobre-Dos-Santos, M.

    2010-09-01

    An increase in the dental caries prevalence on root surfaces has been observed mainly in elderly. This research assessed, in vitro, the effectiveness of a pulsed CO2 (λ = 10.6 μm) laser associated or not with fluoride, in reducing human root dentine demineralization in conditions that mimic an oral high cariogenic challenge. After sterilization, root dentine specimens were randomly assigned into 6 groups ( n = 30), in triplicate. The groups were Control (C), Streptococcus mutans (SM), Fluoride (F), Laser (L), Fluoride + laser (FL), and Laser + fluoride (LF). Except for the control group, all the specimens were inoculated with SM and immersed 3 times a day in a 40% sucrose bath. After a 7-day cariogenic challenge, the mineral loss and lesion depth were evaluated by transverse microradiography and fluoride in the biofilm was determined using an ion-selective electrode. Results were statistically analyzed by analysis of variance, at 5% of significance level. For groups C, SM, F, L, FL and LF, the means (standard-deviation) of mineral loss were 816.3 (552.5)a, 3291.5 (1476.2)c, 2508.5 (1240.5)bc, 2916.2 (1323.7)c, 1839.7 (815.2)b and 1955.0 (1001.4)b, respectively; while lesion depths were 39.6 (22.8)a, 103.1 (38.9)c, 90.3 (44.6)bc, 91.7 (27.0)bc, 73.3 (26.6)b, 75.1 (35.2)b, respectively (different superscript letters indicate significant differences among groups). In conclusion, irradiation of root dentine with a pulsed CO2 laser at fluency of 12.0 J/cm2 was able to inhibit root surface demineralization only when associated with fluoride. No synergy effect on the inhibition of root dentine mineral loss was provided by the combination of fluoride application and laser irradiation.

  5. Current strategies in dentin remineralization.

    PubMed

    Hernández, Marcela; Cobb, Deborah; Swift, Edward J

    2014-01-01

    Partial caries removal procedures are used clinically in an attempt to conserve tooth structure and prevent pulp damage. Within this approach, the caries-infected dentin is removed, and the partially demineralized caries-affected dentin is preserved and sealed with materials that enhance remineralization. Fluoride-releasing glass ionomers have been commonly used for this purpose. Recent studies have shown potential for other cements and bioactive adhesive materials to promote dentin repair through various strategies. These strategies include ion releasing of Ca-P and the guided tissue remineralization or biomimetic remineralization of dentin. The latter is potentially useful in the remineralization of the demineralized acid-etched dentin that is incompletely infiltrated by adhesives in dentin bonding. The purpose of this Critical Appraisal is to provide the clinician with a summary of current literature that clarifies understanding of the process of dentin remineralization and to describe current strategies in this area. PMID:24612484

  6. Effect of Fluoride Varnish Combined with Er:YAG Laser on the Permeability of Eroded Dentin: An In Situ Study.

    PubMed

    Nemezio, Mariana Alencar; Carvalho, Sandra Chiga; Scatolin, Renata Siqueira; Colucci, Vivian; Galo, Rodrigo; Corona, Silmara Aparecida Milori

    2015-01-01

    This study evaluated the combined effect of fluoride varnish and Er:YAG laser on the permeability of eroded bovine root dentin. After initial erosive challenge followed by a remineralization period, the specimens were divided in two groups according to the treatment - fluoride varnish and non-fluoride varnish - and were subdivided according to the irradiation protocol: Er:YAG laser (100 mJ, 3 Hz, 12.8 J/cm2per pulse, non-contact and defocus mode) and non-irradiated. After a lead-in period, 7 volunteers wore a palatal device containing 4 specimens that were subjected to erosive challenges. At the first experimental phase, 4 volunteers used specimens treated with fluoride varnish and fluoride varnish+Er:YAG laser and 3 volunteers used specimens treated with non-fluoride varnish and non-fluoride varnish+Er:YAG laser. After a washout period, volunteers were crossed to treatments, characterizing a 2x2 crossover experiment. At the end of the experimental phase, the quantitative response variable was obtained by permeability analysis and the qualitative response by scanning electron microscopy (SEM). Two-way ANOVA and Tukey-Kramer's test revealed that specimens treated with fluoride varnish+Er:YAG laser showed the lowest permeability and a significant difference was found between this group and the others. When varnish (fluoride/non-fluoride) was applied in the absence of Er:YAG laser, higher permeability was found when compared to the laser-treated groups. SEM evaluations showed partially or completely obliterated dentinal tubules when specimens were treated with fluoride varnish+Er:YAG laser. It may be concluded that Er:YAG laser was able to control the permeability of eroded root dentin and the combination with fluoride varnish increased laser action. PMID:26963215

  7. Erbium:YAG and holmium:YAG laser root resection of extracted human teeth.

    PubMed

    Komori, T; Yokoyama, K; Matsumoto, Y; Matsumoto, K

    1997-02-01

    Root resection of extracted human teeth was performed using the erbium:YAG (Er:YAG) and holmium:YAG (Ho:YAG) laser to investigate the clinical application of lasers on hard tissue. The CO2 laser and the mechanical drill were also used for comparison. After resection using these technologies, the morphological changes of the cut surface were investigated by optical and scanning electron microscope. Er:YAG laser irradiation produced smooth, clean resected surfaces without signs of thermal damages. Complete obturation of the root canal was maintained after Er:YAG laser irradiation. Ho:YAG laser irradiation, however, produced some signs of thermal damage. Relatively large voids between the gutta-percha and the canal walls were revealed after Ho:YAG laser irradiation. The sealing of the dentinal tubules was not completely attained as stipulated by original conditions of this study. PMID:9467336

  8. The effect of dentine location and tubule orientation on the bond strengths between resin and dentine.

    PubMed

    Phrukkanon, S; Burrow, M F; Tyas, M J

    1999-05-01

    This study determined the influence of dentine structure on the micro-tensile bond strengths between resin and dentine of two different dentine adhesive systems (Single Bond, 3M Dental Products, St Paul, MN; MF-102 (experimental self-etching primer), GC Corporation, Tokyo, Japan). The study was separated into two main parts: bond strength measurement and investigation of the bonding interface. Twenty-two human premolars were used for the bond strength measurement. Each tooth was cut vertically, separating the tooth into mesio-distal halves. One half of the tooth was used to bond to a surface perpendicular to the dentinal tubules and other half to bond to a surface parallel to the tubules. For each half, six locations of dentine were bonded. Each material was used in accordance to the manufacturer's directions. Cylindrical hourglass-shaped specimens of 1.2 mm diameter at the bonded interface were manufactured. The bonds were stressed in tension at a crosshead speed of 1 mm/min. Mean bond strengths were compared using LSD, one-way ANOVA, and Student's t-test. The fractured surfaces were examined under a scanning electron microscope, and the frequency of fracture modes was compared using the Kruskal-Wallis and Mann-Whitney U tests. For the investigation of the bonded interface, four teeth were prepared by the same procedure used for the bond test specimens. The bonded interfaces were observed after an acid-base treatment or fracturing across the bonded interface, prior to investigation with a field-emission scanning electron microscope. For Single Bond, the bond strengths for mid-root dentine were significantly lower than for other locations (p < 0.05). For MF-102, there was no significant difference for all locations (p > 0.05). MF-102 bonded well to all locations of dentine while Single Bond showed a porous zone at the base of the hybrid layer. The bonds were not influenced by tubule orientation. The results indicate that the bond for Single Bond may be affected by

  9. Possible role of dentin matrix in region-specific deposition of cellular and acellular extrinsic fibre cementum.

    PubMed

    Takano, Yoshiro; Sakai, Hideo; Watanabe, Eiko; Ideguchi-Ohma, Noriko; Jayawardena, Chantha K; Arai, Kazumi; Asawa, Yukiyo; Nakano, Yukiko; Shuda, Yoko; Sakamoto, Yujiro; Terashima, Tatsuo

    2003-01-01

    The mechanism whereby a region-specific deposition of the two types of cementum (cellular cementum and acellular extrinsic fibre cementum) is regulated on the growing root surface was tested using bisphosphonate-affected teeth of young rats and guinea pigs. The animals were injected subcutaneously with 8 or 10 mg P x kg body weight(-1) x day(-1) of 1-hydroxyethylidene-1,1-bisphosphonate (HEBP) for 1 or 2 weeks. In rat molars, HEBP prevented mineralization of newly formed root dentin matrix and totally inhibited de novo deposition of acellular extrinsic fibre cementum. Instead, thick cellular cementum was induced on the non-mineralized root dentin surface, irrespective of the position of the root. In both animals, cellular cementum was also induced on the non-mineralized surface of root analogue dentin in HEBP-affected incisors, where only acellular extrinsic fibre cementum is deposited under normal conditions. In normal rat molars, dentin sialoprotein (DSP) was concentrated along the dentin-cellular cementum border, but not that of dentin and acellular extrinsic fibre cementum. In HEBP-affected rat incisors, DSP was shown to penetrate through the non-mineralized dentin into the surrounding tissues, but not through the mineralized portions. These data suggest that, at the site of cellular cementum formation, putative inducing factors for cellular cementum might diffuse into the periodontal space through the newly deposited mantle dentin matrix before it is mineralized. At earlier stages of root formation, mantle dentin might mineralize more promptly not to allow such diffusion. The timing of mineralization of mantle dentin matrix might be the key determinant of the types of the cementum deposited on the growing root surface. PMID:14756246

  10. Resin–Dentin Bonding Interface After Photochemical Surface Treatment

    PubMed Central

    Sano, Kazunobu; Ichinose, Shizuko; Araki, Kouji

    2015-01-01

    Abstract Objective The aim of this study is to elucidate the structure of the resin–dentin interface formed by photochemical dentin treatment using an argon fluoride (ArF) excimer laser. Background data The ArF excimer laser processes material by photochemical reaction without generating heat, while also providing surface conditioning that enhances material adhesion. In the case of bonding between resin and dentin, we demonstrated in a previous study that laser etching using an ArF excimer laser produced bonding strength comparable to that of the traditional bonding process; however, conditions of the bonding interface have not been fully investigated. Methods A dentin surface was irradiated in air with an ArF excimer laser followed by bonding treatment. Cross sections were observed under light microscope, transmission electron microscope (TEM), and scanning electron microscope, then analyzed using an energy dispersive X-ray spectroscope (EDS): EDS line profiles of the elements C, O, Si, Cl, P, and Ca at the resin–dentin interface were obtained. Results The density of C in resin decreased as it approached the interface, reaching its lowest level within the dentin at a depth of 2 μm from the resin–dentin interface on EDS. There was no hybrid layer observed at the interface on TEM. Therefore, it was suggested that the resin monomer infiltrated into the microspaces produced on the dentin surface by laser abrasion. Conclusions The monomer infiltration without hybrid layer is thought to be the adhesion mechanism after laser etching. Therefore, the photochemical processes at the bonding interface achieved using the ArF excimer laser has great potential to be developed into a new bonding system in dentistry. PMID:25555032

  11. Dentinogenesis and Dentin Sialophosphoprotein (DSPP)

    PubMed Central

    Yamakoshi, Yasuo

    2010-01-01

    Dentin sialophosphoprotein (DSPP) is critical for proper mineralization of tooth dentin, and understanding its structure and function should yield important insights into how dentin biomineralization is controlled. During the recent six years, I have focused on characterizing DSPP-derived proteins isolated from developing porcine teeth. Porcine DSPP is expressed and secreted by odontoblasts and is processed by BMP-1, MMP-20 and MMP-2 into three main parts: dentin sialoprotein (DSP), dentin glycoprotein (DGP), and dentin phosphoprotein (DPP). We have learned that DSP is a proteoglycan that forms covalent dimers, DGP is a phosphorylated glycoprotein, and DPP is a highly phosphorylated intrinsically disordered protein that shows extensive length polymorphisms due to the genetic heterogeneity of its coding region. PMID:20157636

  12. Dead Tracts in Dentine 1

    PubMed Central

    Fish, E. W.

    1928-01-01

    (1) When the dentinal tubules are opened or sufficiently irritated, their contents coagulate and die. (2) Following this, the pulp lays down an impermeable barrier of lime salts (secondary dentine) to protect itself from contact with the dead tubules. Alternatively the pulp itself dies. (3) The evidence that exposed dentine always dies is as follows: (a) Such dentine is insensitive right through to the secondary dentine. (b) The injured dentine is found experimentally to be shut off from the pulp in such a way that fluids cannot enter it. It thus lacks the necessary body fluids to support life. (c) Under an injury the primary dentine is seen to stop abruptly at the original pulp margin, and to be sealed off with a homogeneous barrier of lime salts before the tubules of the secondary dentine start. The tubules of the secondary dentine take origin below this homogeneous layer in fine branches and obviously have no connexion with the injured primary tubules. (d) The injured tubules although walled off from the pulp remain permeable from the mouth and have therefore not died by slow calcification. ImagesFig. 1Fig. 3Fig. 4Fig. 5Fig. 6Fig. 7 PMID:19986764

  13. Dentin Hypersensitivity and Oxalates

    PubMed Central

    Cunha-Cruz, J.; Stout, J.R.; Heaton, L.J.; Wataha, J.C.

    2011-01-01

    Treatment of dentin hypersensitivity with oxalates is common, but oxalate efficacy remains unclear. Our objective was to systematically review clinical trials reporting an oxalate treatment compared with no treatment or placebo with a dentin hypersensitivity outcome. Risk-of-bias assessment and data extraction were performed independently by two reviewers. Standardized mean differences (SMD) were estimated by random-effects meta-analysis. Of 677 unique citations, 12 studies with high risk-of-bias were included. The summary SMD for 3% monohydrogen-monopotassium oxalate (n = 8 studies) was -0.71 [95% Confidence Interval: -1.48, 0.06]. Other treatments, including 30% dipotassium oxalate (n = 1), 30% dipotassium oxalate plus 3% monohydrogen monopotassium oxalate (n = 3), 6% monohydrogen monopotassium oxalate (n = 1), 6.8% ferric oxalate (n = 1), and oxalate-containing resin (n = 1), also were not statistically significantly different from placebo treatments. With the possible exception of 3% monohydrogen monopotassium oxalate, available evidence currently does not support the recommendation of dentin hypersensitivity treatment with oxalates. PMID:21191127

  14. Removal of organic debris from bovine dentin shavings.

    PubMed

    Kamburis, J J; Barker, T H; Barfield, R D; Eleazer, P D

    2003-09-01

    A common problem with root canal failures is chronic inflammation at the apex caused by overfilling of root canal materials. Dentin filings have been suggested as an apical plug to create a biocompatible barrier between the filling material and the periapical tissue. Unfortunately residual organic material, such as pulp remnants or bacteria, still may be part of the filings. Dentin filings removed from the tooth, cleaned, and then used to form a barrier might serve as an effective barrier. The purpose of this study was to evaluate methods of cleaning dentin of organic debris. NaOCl, sodium dodecyl sulfate, and 1% Triton X-100 were used to treat dentin shavings and were evaluated by a micro bicinchoninic acid protein analysis assay. Two series of experiments were performed. One compared the effect of temperature while using phosphate-buffered saline as a control and the second compared exposure times. The percentage of protein extracted from dentin samples increased with temperature. Sodium hypochlorite at room temperature extracted 24.6%, NaOCl at 37 degrees C extracted 26.9%, and NaOCl at 70 degrees C extracted 33.9%. Only NaOCl at 37 degrees C and 70 degrees C showed statistically significant differences from phosphate-buffered saline at room temperature with p-values of 0.028 and 0.019, respectively. The exposure time series showed a difference between a phosphate-buffered saline solution and 6.25% NaOCl. NaOCl removed approximately 90% of protein compared with 60% for the phosphate-buffered saline. A 10-min exposure to 70 degrees C 6.25% NaOCl may be an efficient means of removing organic material from dentin shavings. PMID:14503826

  15. Machining human dentin by abrasive water jet drilling.

    PubMed

    Kohorst, Philipp; Tegtmeyer, Sven; Biskup, Christian; Bach, Friedrich-Wilhelm; Stiesch, Meike

    2014-01-01

    The aim of this experimental in-vitro study was to investigate the machining of human dentin using an abrasive water jet and to evaluate the influence of different abrasives and water pressures on the removal rate. Seventy-two human teeth had been collected after extraction and randomly divided into six homogeneous groups (n=12). The teeth were processed in the area of root dentin with an industrial water jet device. Different abrasives (saccharose, sorbitol, xylitol) and water pressures (15 or 25 MPa) were used in each group. Dimensions of dentin removal were analysed using a stripe projection microscope and both drilling depth as well as volume of abrasion were recorded. Morphological analyses of the dentin cavities were performed using scanning electron microscopy (SEM). Both drilling depth and volume of abrasion were significantly influenced by the abrasive and the water pressure. Depending on these parameters, the drilling depth averaged between 142 and 378 μm; the volume of abrasion averaged between 0.07 and 0.15 mm3. Microscopic images revealed that all cavities are spherical and with clearly defined margins. Slight differences between the abrasives were found with respect to the microroughness of the surface of the cavities. The results indicate that abrasive water jet machining is a promising technique for processing human dentin. PMID:24642975

  16. Assessment of dentin remineralization with PS-OCT

    NASA Astrophysics Data System (ADS)

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

    2009-02-01

    Previous studies have demonstrated that polarization sensitive optical coherence tomography (PS-OCT) can be used to image natural root caries lesions, measure non-destructively the severity of dentin demineralization and determine the efficacy of intervention with anti-caries agents including fluoride and lasers. The objective of this study was to determine if PS-OCT could be used to nondestructively measure the formation of a layer of remineralized dentin on the surface of dentin lesions after exposure to a remineralization solution. In this study images of artificial dentin lesions on extracted human teeth were acquired using PS-OCT after exposure to an artificial demineralizing solution at pH 4.9 for six days and after subsequent exposure to a remineralizing solution at pH 7.0 for 20 days. Polarized light microscopy and microradiography were used to examine histological thin sections from the samples for comparison. PS-OCT successfully measured the formation of a layer of increased mineral content near the lesion surface. PLM and TMR corroborated those results. This study demonstrates the potential use of PS-OCT for the nondestructive measurement of the remineralization of dentin surfaces.

  17. Clinical effect of photodynamic therapy on primary carious dentin after partial caries removal.

    PubMed

    Neves, Pierre Adriano Moreno; Lima, Leonardo Abrantes; Rodrigues, Fernanda Cristina Nogueira; Leitão, Tarcisio Jorge; Ribeiro, Cecília Cláudia Costa

    2016-05-20

    This study was conducted to assess the clinical effect of photodynamic therapy (PDT) in the decontamination of the deep dentin of deciduous molars submitted to partial removal of carious tissue. After cavity preparation, dentin samples were taken from the pulp wall of nineteen deciduous molars before and after PDT application. Remaining dentin was treated with 0.01% methylene blue dye followed by irradiation with an InGaAlP diode laser (λ - 660 nm; 40 mW; 120 J/cm2; 120 s). Dentin samples were microbiologically assessed for the enumeration of total microorganisms, Lactobacillus spp. and mutans streptococci. There was no significant difference in the number of colony-forming units (CFU) for any of the microorganisms assessed (p > 0.05). Photodynamic therapy, using 0.01% methylene blue dye at a dosimetry of 120 J/cm2 would not be a viable clinical alternative to reduce bacterial contamination in deep dentin. PMID:27223131

  18. The effect of endodontic regeneration medicaments on mechanical properties of radicular dentin

    NASA Astrophysics Data System (ADS)

    Yassen, Ghaeth H.

    Endodontic regeneration treatment of necrotic immature teeth has gained popularity in recent years. The approach suggests a biological alternative to induce a continuous root development. In this project, three in vitro experiments were conducted to investigate the effect of three medicaments used in endodontic regeneration on mechanical properties and chemical structure of radicular dentin. In the first experiment, we investigated longitudinally the effect of medicaments on the indentation properties of the root canal surface of immature teeth using a novel BioDent reference point indenter. A significant difference in the majority of indentation parameters between all groups was found after one-week and one-month application of medicaments (p double antibiotic paste (DAP) > control > calcium hydroxide [Ca(OH)2]. The four-week exposure of dentin to TAP and DAP caused 43% and 31% increase in total indentation distance outcome, respectively. In the second experiment, we investigated longitudinally the effect of medicaments on the chemical structure of immature radicular dentin by measuring the phosphate/amide I ratios of dentin using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy. Phosphate/amide I ratios were significantly different between the four groups after one week, two weeks and four week application of medicaments (p untreated dentin > DAP-treated dentin > TAP-treated dentin. In the third experiment, we investigated longitudinally the effect of medicaments on root fracture resistance and microhardness of radicular dentin. For the microhardness, the two-way interaction between group and time was significant (p<0.001). TAP and DAP caused a significant and continuous decrease in dentin microhardness after one and three month application, respectively. The three-month intracanal application of Ca(OH)2 significantly increased the microhardness of root dentin. The time factor had a significant effect on fracture resistance (p<0.001). All

  19. Morphometric analysis of root canal cleaning after rotary instrumentation with or without laser irradiation

    NASA Astrophysics Data System (ADS)

    Marchesan, Melissa A.; Geurisoli, Danilo M. Z.; Brugnera, Aldo, Jr.; Barbin, Eduardo L.; Pecora, Jesus D.

    2002-06-01

    The present study examined root canal cleaning, using the optic microscope, after rotary instrumentation with ProFile.04 with or without laser application with different output energies. Cleaning and shaping can be accomplished manually, with ultra-sonic and sub-sonic devices, with rotary instruments and recently, increasing development in laser radiation has shown promising results for disinfection and smear layer removal. In this study, 30 palatal maxillary molar roots were examined using an optic microscope after rotary instrumentation with ProFile .04 with or without Er:YAG laser application (KaVo KeyLaser II, Germany) with different output energies (2940 nm, 15 Hz, 300 pulses, 500 milli-sec duration, 42 J, 140 mJ showed on the display- input, 61 mJ at fiberoptic tip-output and 140 mJ showed on the display-input and 51 mJ at fiberoptic tip-output). Statistical analysis showed no statistical differences between the tested treatments (ANOVA, p>0.05). ANOVA also showed a statistically significant difference (p<0.01) between the root canal thirds, indicating that the middle third had less debris than the apical third. We conclude that: 1) none of the tested treatments led to totally cleaned root canals; 2) all treatments removed debris similarly, 3) the middle third had less debris than the apical third; 4) variation in output energy did not increase cleaning.

  20. Investigation of Er:YAG laser root canal irradiation using en face OCT

    NASA Astrophysics Data System (ADS)

    Todea, Carmen; Balabuc, Cosmin; Filip, Laura; Calniceanu, Mircea; Bradu, Adrian; Hughes, Michael; Podoleanu, Adrian G.

    2009-07-01

    This pilot study was designed to investigate the quality of endodontic treatment performed with/without Er:YAG laser using en-face Optical Coherence Tomography (OCT) prototype which evinced the presence of voids and microleakage within the root canal.

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

    PubMed Central

    Huang, George T.-J.

    2012-01-01

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

  2. Effects of heating by steam autoclaving and Er:YAG laser etching on dentin components.

    PubMed

    Soares, Luís Eduardo S; Brugnera, Aldo; Zanin, Fátima A A; Santo, Ana Maria E; Martin, Airton A

    2011-09-01

    The simultaneous need for infection-control protocols in sample preparations and for safe laser irradiation parameters prompted this study about the effects of heat produced by both sample sterilization and laser etching on dentin components. The dentin was exposed on 30 bovine incisors, and then divided into two main groups: autoclaved (group A) or thymol treatment (group B). The surface of the dentin was schematically divided into four areas, with each one corresponding to a treatment subgroup. The specimens were either etched with phosphoric acid (control-CG) or irradiated with Er:YAG laser (subgroups: I-80 mJ, II-120 mJ, and III-180 mJ). Elemental distribution maps were done by energy-dispersive X-ray fluorescence (μ-EDXRF) on each treatment area. The dentin surface in depth was exposed and line-scan maps were performed. The B_CG treatment produced the best distribution of calcium (Ca) and phosphorus (P) content throughout the dentin surface. Er:YAG laser etching produced irregular patterns of elemental distribution in the dentin. Laser energies of 120 and 180 mJ produced the highest maximum calcium values. The Er:YAG laser energy of 180 mJ produced a localized increase in Ca and P content on the superficial layer of the dentin (∼ 0-0.10 mm). The autoclaving treatment of samples in experiments is not recommended since it produced damaging effects on dentin components. Er:YAG laser irradiation produced a heterogeneous Ca and P distribution throughout the dentin surface with areas of increased Ca concentration, and this may affect clinically the permeability, solubility, or adhesive characteristics of dental hard tissues with restorative procedures. PMID:20625787

  3. Photomechanical investigations on the stress-strain relationship in dentine macrostructure.

    PubMed

    Kishen, A; Asundi, A

    2005-01-01

    In this study photomechanical experiments were carried out to examine the relationship between macroscopic mechanical stress and strain gradients within the root dentine structure. Three-dimensional digital photoelasticity was used to study the stress distribution patterns in tooth models, while digital moire interferometry was used to study the strain gradients within the natural teeth. The stress analysis showed a distinct bending stress distribution, along faciolingual plane in the coronal and cervical regions of the tooth. There was a reduction in bending towards the apical third of the tooth model. The strain analysis displayed strain gradients in the axial (along the long axis of the tooth) and lateral (perpendicular to the long axis of the tooth) directions in dentine. There was a conspicuous reduction in strains from the cervical to the apical third of the root dentine. The root dentine displayed uniform distribution of normal strains. Although there was a steep increase in stresses from the inner core region to the outer surface of an isotropic tooth model, there were more uniform strain gradients in the natural dentine structure. It is apparent from these observations that complex organization of material properties facilitated distinct strain gradients in dentine structure during mechanical functions. PMID:16229654

  4. Anacardic acid from brazilian cashew nut trees reduces dentine erosion.

    PubMed

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

    2014-01-01

    The aim of this study was to analyze the effect of solutions containing saturated anacardic acid (AA) on dentine erosion in vitro. AA was chemically isolated from natural cashew nutshell liquid obtained by continuous extraction in a Soxhlet extractor and was fully saturated by catalytic hydrogenation. Matrix metalloproteinase 2 (MMP-2) activity, when exposed to buffers containing 100 µmol/l AA, was analyzed using zymography. Bovine root samples were subjected to erosive demineralization (Sprite Zero™, 4 × 90 s/day) and remineralization with artificial saliva between the erosive cycles for 5 days. The samples were treated as follows, after the first and the last acid exposure (1 min; n = 12/group): (1) 100 µmol/l epigallocatechin-3-gallate (EGCG) (positive control); (2) 0.05% NaF; (3) 100 µmol/l saturated AA; (4) saturated AA and EGCG; (5) saturated AA, EGCG and NaF; (6) untreated (negative control). Dentine erosion was measured using a contact profilometer. Two dentine samples from each group were analyzed using scanning electron microscopy. Saturated AA reduced the activity of MMP-2. ANOVA and Tukey's test revealed that all treatments significantly reduced dentine loss compared to the negative control (6.03 ± 0.98 µm). Solutions containing saturated AA (1.97 ± 1.02 µm) showed the greatest reduction in dentine erosion compared to the NaF (3.93 ± 1.54 µm) and EGCG (3.79 ± 0.83 µm) solutions. Therefore, it may be concluded that AA significantly reduces dentine erosion in vitro, possibly by acting as an MMP-2 inhibitor. PMID:24993776

  5. Effect of Lesion Baseline Severity and Mineral Distribution on Remineralization and Progression of Human and Bovine Dentin Caries Lesions.

    PubMed

    Lippert, Frank; Churchley, David; Lynch, Richard J

    2015-01-01

    The aims of this laboratory study were to compare the effects of lesion baseline severity, mineral distribution and substrate on remineralization and progression of caries lesions created in root dentin. Lesions were formed in dentin specimens prepared from human and bovine dentin using three protocols, each utilizing three demineralization periods to create lesions of different mineral distributions (subsurface, moderate softening, extreme softening) and severity within each lesion type. Lesions were then either remineralized or demineralized further and analyzed using transverse microradiography. At lesion baseline, no differences were found between human and bovine dentin for integrated mineral loss (x0394;Z). Differences in mineral distribution between lesion types were apparent. Human dentin lesions were more prone to secondary demineralization (x0394;x0394;Z) than bovine dentin lesions, although there were no differences in x0394;L. Likewise, smaller lesions were more susceptible to secondary demineralization than larger ones. Subsurface lesions were more acid-resistant than moderately and extremely softened lesions. After remineralization, differences between human and bovine dentin lesions were not apparent for x0394;x0394;Z although bovine dentin lesions showed greater reduction in lesion depth L. For lesion types, responsiveness to remineralization (x0394;x0394;Z) was in the order extremely softened>moderately softened>subsurface. More demineralized lesions exhibited greater remineralization than shallower ones. In summary, some differences exist between human and bovine dentin and their relative responsiveness to de- and remineralization. These differences, however, were overshadowed by the effects of lesion baseline mineral distribution and severity. Thus, bovine dentin appears to be a suitable substitute for human dentin in mechanistic root caries studies. PMID:26228732

  6. Simultaneous effects of leaf irradiance and soil moisture on growth and root system architecture of novel wheat genotypes: implications for phenotyping.

    PubMed

    Nagel, Kerstin A; Bonnett, David; Furbank, Robert; Walter, Achim; Schurr, Ulrich; Watt, Michelle

    2015-09-01

    Plants in the field are exposed to varying light and moisture. Agronomic improvement requires knowledge of whole-plant phenotypes expressed in response to simultaneous variation in these essential resources. Most phenotypes, however, have been described from experiments where resources are varied singularly. To test the importance of varying shoot and root resources for phenotyping studies, sister pre-breeding lines of wheat were phenotyped in response to independent or simultaneous exposure to two light levels and soil moisture profiles. The distribution and architecture of the root systems depended strongly on the moisture of the deeper soil layer. For one genotype, roots, specifically lateral roots, were stimulated to grow into moist soil when the upper zone was well-watered and were inhibited by drier deep zones. In contrast, the other genotype showed much less plasticity and responsiveness to upper moist soil, but maintained deeper penetration of roots into the dry layer. The sum of shoot and root responses was greater when treated simultaneously to low light and low soil water, compared to each treatment alone, suggesting the value of whole plant phenotyping in response to multiple conditions for agronomic improvement. The results suggest that canopy management for increased irradiation of leaves would encourage root growth into deeper drier soil, and that genetic variation within closely related breeding lines may exist to favour surface root growth in response to irrigation or in-season rainfall. PMID:26089535

  7. Simultaneous effects of leaf irradiance and soil moisture on growth and root system architecture of novel wheat genotypes: implications for phenotyping

    PubMed Central

    Nagel, Kerstin A.; Bonnett, David; Furbank, Robert; Walter, Achim; Schurr, Ulrich; Watt, Michelle

    2015-01-01

    Plants in the field are exposed to varying light and moisture. Agronomic improvement requires knowledge of whole-plant phenotypes expressed in response to simultaneous variation in these essential resources. Most phenotypes, however, have been described from experiments where resources are varied singularly. To test the importance of varying shoot and root resources for phenotyping studies, sister pre-breeding lines of wheat were phenotyped in response to independent or simultaneous exposure to two light levels and soil moisture profiles. The distribution and architecture of the root systems depended strongly on the moisture of the deeper soil layer. For one genotype, roots, specifically lateral roots, were stimulated to grow into moist soil when the upper zone was well-watered and were inhibited by drier deep zones. In contrast, the other genotype showed much less plasticity and responsiveness to upper moist soil, but maintained deeper penetration of roots into the dry layer. The sum of shoot and root responses was greater when treated simultaneously to low light and low soil water, compared to each treatment alone, suggesting the value of whole plant phenotyping in response to multiple conditions for agronomic improvement. The results suggest that canopy management for increased irradiation of leaves would encourage root growth into deeper drier soil, and that genetic variation within closely related breeding lines may exist to favour surface root growth in response to irrigation or in-season rainfall. PMID:26089535

  8. Domain of Dentine Sialoprotein Mediates Proliferation and Differentiation of Human Periodontal Ligament Stem Cells

    PubMed Central

    Yang, Guobin; Wang, Feng; Li, Wentong; Yang, Yuan; Guo, Feng; Gao, Qingping; Shoff, Lisa; Chen, Zhi; Gay, Isabel C.; Donly, Kevin J.; MacDougall, Mary; Chen, Shuo

    2013-01-01

    Classic embryological studies have documented the inductive role of root dentin on adjacent periodontal ligament differentiation.  The biochemical composition of root dentin includes collagens and cleavage products of dentin sialophosphoprotein (DSPP), such as dentin sialoprotein (DSP).  The high abundance of DSP in root dentin prompted us to ask the question whether DSP or peptides derived thereof would serve as potent biological matrix components to induce periodontal progenitors to further differentiate into periodontal ligament cells. Here, we test the hypothesis that domain of DSP influences cell fate. In situ hybridization and immunohistochemical analyses showed that the COOH-terminal DSP domain is expressed in mouse periodontium at various stages of root development. The recombinant COOH-terminal DSP fragment (rC-DSP) enhanced attachment and migration of human periodontal ligament stem cells (PDLSC), human primary PDL cells without cell toxicity. rC-DSP induced PDLSC cell proliferation as well as differentiation and mineralization of PDLSC and PDL cells by formation of mineralized tissue and ALPase activity. Effect of rC-DSP on cell proliferation and differentiation was to promote gene expression of tooth/bone-relate markers, transcription factors and growth factors. The results for the first time showed that rC-DSP may be one of the components of cell niche for stimulating stem/progenitor cell proliferation and differentiation and a natural scaffold for periodontal regeneration application. PMID:24400037

  9. Polymer nanocarriers for dentin adhesion.

    PubMed

    Osorio, R; Osorio, E; Medina-Castillo, A L; Toledano, M

    2014-12-01

    To obtain more durable adhesion to dentin, and to protect collagen fibrils of the dentin matrix from degradation, calcium- and phosphate-releasing particles have been incorporated into the dental adhesive procedure. The aim of the present study was to incorporate zinc-loaded polymeric nanocarriers into a dental adhesive system to facilitate inhibition of matrix metalloproteinases (MMPs)-mediated collagen degradation and to provide calcium ions for mineral deposition within the resin-dentin bonded interface. PolymP- N : Active nanoparticles (nanoMyP) were zinc-loaded through 30-minute ZnCl2 immersion and tested for bioactivity by means of 7 days' immersion in simulated body fluid solution (the Kokubo test). Zinc-loading and calcium phosphate depositions were examined by scanning and transmission electron microscopy, elemental analysis, and x-ray diffraction. Nanoparticles in ethanol solution infiltrated into phosphoric-acid-etched human dentin and Single Bond (3M/ESPE) were applied to determine whether the nanoparticles interfered with bonding. Debonded sticks were analyzed by scanning electron microscopy. A metalloproteinase collagen degradation assay was also performed in resin-infiltrated dentin with and without nanoparticles, measuring C-terminal telopeptide of type I collagen (ICTP) concentration in supernatants, after 4 wk of immersion in artificial saliva. Numerical data were analyzed by analysis of variance (ANOVA) and Student-Newman-Keuls multiple comparisons tests (p < .05). Nanoparticles were effectively zinc-loaded and were shown to have a chelating effect, retaining calcium regardless of zinc incorporation. Nanoparticles failed to infiltrate demineralized intertubular dentin and remained on top of the hybrid layer, without altering bond strength. Calcium and phosphorus were found covering nanoparticles at the hybrid layer, after 24 h. Nanoparticle application in etched dentin also reduced MMP-mediated collagen degradation. Tested nanoparticles may be

  10. Polymer Nanocarriers for Dentin Adhesion

    PubMed Central

    Osorio, R.; Osorio, E.; Medina-Castillo, A.L.; Toledano, M.

    2014-01-01

    To obtain more durable adhesion to dentin, and to protect collagen fibrils of the dentin matrix from degradation, calcium- and phosphate-releasing particles have been incorporated into the dental adhesive procedure. The aim of the present study was to incorporate zinc-loaded polymeric nanocarriers into a dental adhesive system to facilitate inhibition of matrix metalloproteinases (MMPs)-mediated collagen degradation and to provide calcium ions for mineral deposition within the resin-dentin bonded interface. PolymP-nActive nanoparticles (nanoMyP) were zinc-loaded through 30-minute ZnCl2 immersion and tested for bioactivity by means of 7 days’ immersion in simulated body fluid solution (the Kokubo test). Zinc-loading and calcium phosphate depositions were examined by scanning and transmission electron microscopy, elemental analysis, and x-ray diffraction. Nanoparticles in ethanol solution infiltrated into phosphoric-acid-etched human dentin and Single Bond (3M/ESPE) were applied to determine whether the nanoparticles interfered with bonding. Debonded sticks were analyzed by scanning electron microscopy. A metalloproteinase collagen degradation assay was also performed in resin-infiltrated dentin with and without nanoparticles, measuring C-terminal telopeptide of type I collagen (ICTP) concentration in supernatants, after 4 wk of immersion in artificial saliva. Numerical data were analyzed by analysis of variance (ANOVA) and Student-Newman-Keuls multiple comparisons tests (p < .05). Nanoparticles were effectively zinc-loaded and were shown to have a chelating effect, retaining calcium regardless of zinc incorporation. Nanoparticles failed to infiltrate demineralized intertubular dentin and remained on top of the hybrid layer, without altering bond strength. Calcium and phosphorus were found covering nanoparticles at the hybrid layer, after 24 h. Nanoparticle application in etched dentin also reduced MMP-mediated collagen degradation. Tested nanoparticles may be

  11. In vitro photodynamic antimicrobial chemotherapy in dentine contaminated by cariogenic bacteria

    NASA Astrophysics Data System (ADS)

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

    2010-06-01

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

  12. Dentinal crazing and interpin distance.

    PubMed

    Khera, S C; Chan, K C; Rittman, B R

    1978-11-01

    All three types of self-threading plus cause dentinal crazing. The frequency and degree of damage done to the dentin varies significantly between the three types of pins and depends upon the differences in the diameters of the drill and the pin. When two or more pins are placed in dentin, the potential for dentinal damage increases. Minikin pins (0.019-inch diameter) caused the least damage, in terms of both degree and frequency. The optimum and safe interpin distance using Minikin pins suggested by this study is 3 mm. Minim and Regular pins (0.023- and 0.031-inch diameters, respectively) caused more injury than Minikin pins. The Regular pins showed more damaging effects on dentin than Minim pins, both in terms of degree and frequency. On the basis of this study, the minimum interpin distance using Minim or Regular pins should be 5 mm. These minimum interpin distances are applicable only in situations where the dentin is not dehydrated or embrittled due to endodontic treatment. In teeth that have been endodontically treated, it would be advisable to use only the smallest self-threading pins and possibly increase the interpin distance if two or more pins are to be used. PMID:281504

  13. Remineralization of artificial dentinal caries lesions by biomimetically modified mineral trioxide aggregate.

    PubMed

    Qi, Yi-pin; Li, Nan; Niu, Li-na; Primus, Carolyn M; Ling, Jun-Qi; Pashley, David H; Tay, Franklin R

    2012-02-01

    Fluoride-releasing restorative materials are available for remineralization of enamel and root caries. However, remineralization of dentin is more difficult than remineralization of enamel due to the paucity of apatite seed crystallites along the lesion surface for heterogeneous crystal growth. Extracellular matrix proteins play critical roles in controlling apatite nucleation/growth in collagenous tissues. This study examined the remineralization efficacy of mineral trioxide aggregate (MTA) in phosphate-containing simulated body fluid (SBF) by incorporating polyacrylic acid and sodium tripolyphosphate as biomimetic analogs of matrix proteins for remineralizing caries-like dentin. Artificial caries-like dentin lesions incubated in SBF were remineralized over a 6 week period using MTA alone or MTA containing biomimetic analogs in the absence or presence of dentin adhesive application. Lesion depths and integrated mineral loss were monitored with microcomputed tomography. The ultrastructure of baseline and remineralized lesions was examined by transmission electron microscopy. Dentin remineralization was best achieved using MTA containing biomimetic analogs regardless of whether an adhesive was applied; dentinal tubules within the remineralized dentin were occluded by apatite. It is concluded that the version of MTA employed in this study may be doped with biomimetic analogs for remineralization of unbonded and bonded artificial caries-like lesions in the presence of SBF. PMID:22085925

  14. In vitro evaluation of smear layer removal of root canals by irradiation with Er:YAG laser after Ni-Ti rotary instrumentation

    NASA Astrophysics Data System (ADS)

    Capelli, Alexandre; Brugnera, Aldo, Jr.; Heredia Seixas, Fabio; Marchesan, Melissa A.; Zanello Guerisoli, Danilo M.; Djalma Pecora, Jesus

    2003-06-01

    The smear layer removal of root canal walls irradiated with Er:YAG laser after nickel-titanium rotary instrumentation was evaluated by scanning electron microscopy. Thirty mesial roots of human mandibular molars were selected and randomly distributed in three groups, according to treatment. Group 1 was instrumented with rotary nickel-titanium files 1 mm from the anatomical apex and irrigated with 2.5% sodium hypochlorite. Group 2 received the same treatment as Group 1, but after instrumentation the root canals were irradiated with Er:YAG laser. Group 3 received the same treatment as Group 1, but irrigation was performed with 2.5% sodium hypochlorite alternated wtih 17% EDTA during instrumentation. Photomicrographs were obtained from middle and apical thirds and submitted to qualitative evaluation. Statistical analysis showed that 2.5% sodium hypochlorite associated with 17% EDTA (Group 3) removed smear layer more efficiently than 2.5% sodium hypochlorite al one (Group 1) (p<0.05). Root canals irradiated with Er:YAG laser occupied an intermediary position regarding smear layer removal. There were no statistical differences between the evaluated radicular thirds (p>0.05).

  15. Dentin dysplasia type I: a challenge for treatment with dental implants

    PubMed Central

    Depprich, Rita A; Ommerborn, Michelle A; Handschel, Jörg GK; Naujoks, Christian D; Meyer, Ulrich; Kübler, Norbert R

    2007-01-01

    Background Dentin dysplasia type I is characterized by a defect of dentin development with clinical normal appearance of the permanent teeth but no or only rudimentary root formation. Early loss of all teeth and concomitant underdevelopment of the jaws are challenging for successful treatment with dental implants. Methods A combination of sinus lifting and onlay bone augmentation based on treatment planning using stereolithographic templates was used in a patient with dentin dysplasia type I to rehabilitate the masticatory function. Results (i) a predisposition for an increased and accelerated bone resorption was observed in our patient, (ii) bone augmentation was successful using a mixture of allogenic graft material with autogenous bone preventing fast bone resorption, (iii) surgical planning, based on stereolithographic models and surgical templates, facilitated the accurate placement of dental implants. Conclusion Bony augmentation and elaborate treatment planning is helpful for oral rehabilitation of patients with dentin dysplasia type I. PMID:17714586

  16. Evaluation of the Diode laser (810nm,980nm) on dentin tubule diameter following internal bleaching

    PubMed Central

    Kiomarsi, Nazanin; Salim, Soheil; Sarraf, Pegah; Javad-Kharazifard, Mohammad

    2016-01-01

    Background The aim of this study was to evaluate the effect of diode laser irradiation and bleaching materials on the dentinal tubule diameter after laser bleaching. Material and Methods The dentin discs of 40 extracted third molar were used in this experiment. Each disc surface was divided into two halves by grooving. Half of samples were laser bleached at different wavelengths with two different concentrations of hydrogen peroxide. Other half of each disc with no laser bleaching remained as a negative control. Dentin discs were assigned randomly into four groups (n=10) with following hydrogen peroxide and diode laser wavelength specifications; Group 1 (30% - 810 nm), group 2 (30% - 980 nm), group 3 (46% - 810 nm) and group 4 (46% - 980 nm). All specimens were sent for scanning electron microscopic (SEM) analysis in order to measure tubular diameter in laser treated and control halves. Data were analyzed by ANOVA and Tukey test (p<0.05). Results A significant reduction in dentin tubule diameter was observed in groups 1, 2 and 4. There was no significant difference between groups 1 and 2 and between groups 3 and 4 after bleaching. Conclusions The SEM results showed that diode laser was able to reduce dentin tubule diameter and its effect on dentin was dependent on chemical action of bleaching material. Key words:Laser, diode, dentin, tubule, diameter. PMID:27398172

  17. The sensory mechanism in human dentin as revealed by evaporation and mechanical removal of dentin.

    PubMed

    Brännström, M; Johnson, G

    1978-01-01

    Dentinal pain in connection with mechanical stimulation i.e. probing, chiseling and initial drilling may be due to removal of fluid from the dentinal tubules. Loss of fluid due to "normal" evaporation from exposed dentin may produce an outward flow in the dentinal tubules rapid enough to cause pain and within a few minutes odontoblast aspiration. PMID:277500

  18. Sodium hypochlorite alterations of dentin and dentin collagen

    NASA Astrophysics Data System (ADS)

    Marshall, G. W.; Yücel, N.; Balooch, M.; Kinney, J. H.; Habelitz, S.; Marshall, S. J.

    2001-10-01

    NaOCl aq is used as a cleansing and non-specific deproteinizing agent in endodontic treatment, as a component of new chemomechanical caries treatment, and is under study for its alterations of dentin bonding characteristics. We sought to determine the microstructural and nanomechanical changes with such treatments and to test if NaOCl aq removed dentin collagen without microstructural or nanomechanical alteration of underlying mineralized dentin. Polished human dentin disks were prepared with a double reference technique that allowed changes to be determined following 10% citric acid etching for 15 s and subsequent treatment of the etched and unetched portions of the sample with 6.5% NaOCl aq, using atomic force microscopy (AFM) (Nanoscope III, Digital Instruments, Santa Barbara, CA). Images and measurements were made at intervals up to 1800 s. A Triboscope (Hysitron, Minneapolis, MN) on the AFM was used to measure nanohardness and the reduced elastic modulus. The double reference method allowed measurements immediately following etching and at intervals during deproteinization. Etching caused deep peritubular dentin removal and a small depth change of hydrated intertubular dentin as mineral was removed and left a remnant collagen matrix. NaOCl aq removed collagen over time, during which individual fibrils could be resolved; the underlying mineralized dentin was left with a unique porous surface containing numerous channels that are not normally observed in etched or fractured dentin. This could provide an attractive bonding substrate because of the increased surface area and high mineral content, if toughness is not reduced too much. Nanomechanical measurements showed that the reduced elastic modulus and hardness were 75% of original values after removal of the exposed collagen. Current dentin bonding systems rely on hybrid layer formation in which hydrophilic primers/polymers penetrate the opened collagen matrix exposed by etching. However some research suggests

  19. Hyperlipidemia induced by high-fat diet enhances dentin formation and delays dentin mineralization in mouse incisor.

    PubMed

    Ye, Xin; Zhang, Jin; Yang, Pishan

    2016-10-01

    Dyslipidemia has become a serious health problem in children and adolescents worldwide for its high prevalence. Since hard tissues of permanent teeth form mainly during this period and lipids are actively involved in tooth development, the effects of hyperlipidemia on dental tissue formation and mineralization need to be illustrated. In this study, hyperlipidemia model was established in mice fed with high-fat diet (HFD). Micro-CT and histomorphological analyses were performed on the mandibular bones to assess the morphological changes of the mandibular incisor and first molar. After 4 weeks of HFD feeding, mice had significantly elevated serum lipid levels compared with mice fed with control diet. After 8 weeks, the mandibular incisor presented significantly increased dentin thickness and decreased diameter of pulp cavity in HFD-fed mice compared with control diet-fed mice, while its gross morphology and enamel thickness were not altered. In the mandibular first molar, dentin thickness of root did not show difference between the two groups. Histological section showed that mandibular incisor of HFD-fed mice manifested a wider predentin region and a lower mineral apposition rate compared with that of the control mice. In conclusion, hyperlipidemia induced by HFD feeding enhances dentin formation and delays dentin mineralization in the developing mouse incisor. PMID:27558143

  20. Influence of remaining dentin wall thickness on the fracture strength of endodontically treated tooth

    PubMed Central

    Haralur, Satheesh B.; Al-Qahtani, Ali Saad; Al-Qarni, Marie Mohammed; Al-Homrany, Rami Mohammed; Aboalkhair, Ayyob Ehsan

    2016-01-01

    Background: Remaining dentin wall thickness may influence the fracture resistance of tooth. Aims: To investigate the effect of various coronal dentin wall widths on the fracture strength of root canal treated teeth. Materials and Methods: Fifty recently extracted single canal mandibular premolars were used for the study. Ten unrestored teeth were used as control (Group 1); remaining teeth were root canal treated and divided into four groups (n = 10). The Groups 2a, 2b and 3a, 3b were having 2.5 mm, 1.5 mm remaining dentin with and without post, respectively. The samples fracture resistance was tested under the universal testing machine. The data were analyzed with one-way ANOVA and post-hoc Tukey test for comparative evaluation. Results: The mean fracture strength observed in Group 1 was (29.75 Mpa) followed by Group 2a (28.97 Mpa), Group 2b (27.70 Mpa), Group 3a (23.39 Mpa), and Group 3b (16.38 Mpa). There was no statistically significant difference between control and Groups 2a and 2b with P > 0.05. The post contributed significantly for fracture resistance in Group 3a. Conclusion: The endodontic post is not required in root canal treated teeth >2.5 mm coronal dentin wall width while the post is essential for a tooth with <1.5 mm dentin wall width to improve fracture resistance. PMID:26957796

  1. Stereomicroscopic evaluation of dentinal defects induced by new rotary system: “ProTaper NEXT”

    PubMed Central

    Shori, Deepa Deepak; Shenoi, Pratima Ramakrishna; Baig, Arshia R; Kubde, Rajesh; Makade, Chetana; Pandey, Swapnil

    2015-01-01

    Introduction: The objective of this study was to evaluate dentinal defects formed by new rotary system — Protaper next™ (PTN). Materials and Methods: Sixty single-rooted premolars were selected. All specimens were decoronated and divided into four groups, each group having 15 specimens. Group I specimens were prepared by Hand K-files (Mani), Group II with ProTaper Universal (PT; Dentsply Maillefer), Group III with Hero Shaper (HS; Micro-Mega, Besancon, France), and Group IV with PTN (Dentsply Maillefer). Roots of each specimen were sectioned at 3, 6, and 9mm from the apex and were then viewed under a stereomicroscope to evaluate presence or absence of dentinal defects. Results: In roots prepared with hand files (HFs) showed lowest percentage of dentinal defects (6.7%); whereas in roots prepared with PT, HS, and PTN it was 40, 66.7, and 26.7%, respectively. There was significant difference between the HS group and the PTN group (P < 0.05). Conclusion: All rotary files induced defects in root dentin, whereas the hand instruments induced minimal defects. PMID:26069406

  2. Ultrastructural observations on bacterial invasion in cementum and radicular dentin of periodontally diseased human teeth.

    PubMed

    Adriaens, P A; Edwards, C A; De Boever, J A; Loesche, W J

    1988-08-01

    In this study the bacterial invasion in root cementum and radicular dentin of periodontally diseased, caries-free human teeth was examined. In addition, structural changes in these tissues, which could be related to the bacterial invasion, were reported. Twenty-one caries-free human teeth with extensive periodontal attachment loss were studied by light and scanning electron microscopy. At the base of the gingival pocket, bacteria were found in the spaces between remnants of Sharpey's fibers and their point of insertion in the cementum. In teeth that had been scaled and root planed, most of the root cementum had been removed. Bacterial invasion was found in the remaining root cementum. The invasion seemed to start as a localized process, often involving only one bacterium. In other areas bacteria were present in lacunar defects in the cementum. These lacunae extended into the radicular dentin. In 11 teeth bacteria had invaded the dentinal tubules. Most bacteria were located in the outer 300 microns of the dentinal tubules, although occasionally they were found in deeper parts. In two of the nontreated teeth, bacteria were detected on the pulpal wall. No correlation was found between the presence of bacterial invasion and the absence of radicular cementum. No bacteria were found in the portion of the root located apically to the epithelial attachment. These data are in agreement with our results from cultural studies of the bacterial flora in these structures. It was also demonstrated that in spite of meticulous scaling and root planning and personal oral hygiene, bacterial plaque remained present on radicular surfaces. Both the invaded dentinal tubules and the lacunae could act as bacterial reservoirs from which recolonization of treated root surfaces occurs. From these reservoirs bacteria could also induce pulpal pathoses. Since these bacterial reservoirs are not eliminated by conventional mechanical periodontal treatment, it seems appropriate to combine mechanical

  3. Effect of Calcium Hydroxide on the Fracture Resistance of Dentin

    PubMed Central

    Whitbeck, Evan R.; Quinn, George D.; Quinn, Janet B.

    2011-01-01

    An increased incidence of fracture has been reported in teeth where root canals were treated with calcium hydroxide. Edge chipping is one test used to measure the resistance of brittle materials to fracture. Presently, no studies have reported on edge chipping in teeth. This study evaluated the fracture resistance of human dentin exposed to calcium hydroxide for up to 60 days using the edge chipping method. Twelve recently extracted teeth were divided into a control group and three experimental groups with varying calcium hydroxide exposures. All teeth underwent pulpectomy via standard protocol. It was expected that the edge chip resistance would decrease as a function of exposure, but the results showed the converse. Chip resistance may reflect both the fracture resistance and the hardness of dentin, a quasi brittle material. PMID:26989596

  4. Malformations of the tooth root in humans.

    PubMed

    Luder, Hans U

    2015-01-01

    The most common root malformations in humans arise from either developmental disorders of the root alone or disorders of radicular development as part of a general tooth dysplasia. The aim of this review is to relate the characteristics of these root malformations to potentially disrupted processes involved in radicular morphogenesis. Radicular morphogenesis proceeds under the control of Hertwig's epithelial root sheath (HERS) which determines the number, length, and shape of the root, induces the formation of radicular dentin, and participates in the development of root cementum. Formation of HERS at the transition from crown to root development appears to be very insensitive to adverse effects, with the result that rootless teeth are extremely rare. In contrast, shortened roots as a consequence of impaired or prematurely halted apical growth of HERS constitute the most prevalent radicular dysplasia which occurs due to trauma and unknown reasons as well as in association with dentin disorders. While odontoblast differentiation inevitably stops when growth of HERS is arrested, it seems to be unaffected even in cases of severe dentin dysplasias such as regional odontodysplasia and dentin dysplasia type I. As a result radicular dentin formation is at least initiated and progresses for a limited time. The only condition affecting cementogenesis is hypophosphatasia which disrupts the formation of acellular cementum through an inhibition of mineralization. A process particularly susceptible to adverse effects appears to be the formation of the furcation in multirooted teeth. Impairment or disruption of this process entails taurodontism, single-rooted posterior teeth, and misshapen furcations. Thus, even though many characteristics of human root malformations can be related to disorders of specific processes involved in radicular morphogenesis, precise inferences as to the pathogenesis of these dysplasias are hampered by the still limited knowledge on root formation

  5. Malformations of the tooth root in humans

    PubMed Central

    Luder, Hans U.

    2015-01-01

    The most common root malformations in humans arise from either developmental disorders of the root alone or disorders of radicular development as part of a general tooth dysplasia. The aim of this review is to relate the characteristics of these root malformations to potentially disrupted processes involved in radicular morphogenesis. Radicular morphogenesis proceeds under the control of Hertwig's epithelial root sheath (HERS) which determines the number, length, and shape of the root, induces the formation of radicular dentin, and participates in the development of root cementum. Formation of HERS at the transition from crown to root development appears to be very insensitive to adverse effects, with the result that rootless teeth are extremely rare. In contrast, shortened roots as a consequence of impaired or prematurely halted apical growth of HERS constitute the most prevalent radicular dysplasia which occurs due to trauma and unknown reasons as well as in association with dentin disorders. While odontoblast differentiation inevitably stops when growth of HERS is arrested, it seems to be unaffected even in cases of severe dentin dysplasias such as regional odontodysplasia and dentin dysplasia type I. As a result radicular dentin formation is at least initiated and progresses for a limited time. The only condition affecting cementogenesis is hypophosphatasia which disrupts the formation of acellular cementum through an inhibition of mineralization. A process particularly susceptible to adverse effects appears to be the formation of the furcation in multirooted teeth. Impairment or disruption of this process entails taurodontism, single-rooted posterior teeth, and misshapen furcations. Thus, even though many characteristics of human root malformations can be related to disorders of specific processes involved in radicular morphogenesis, precise inferences as to the pathogenesis of these dysplasias are hampered by the still limited knowledge on root formation

  6. Effect of acidic solutions on the microhardness of dentin and set OrthoMTA and their cytotoxicity on murine macrophage

    PubMed Central

    Shon, Won-Jun; Lee, Woocheol

    2016-01-01

    Objectives To evaluate the effects of three acids on the microhardness of set mineral trioxide aggregate (MTA) and root dentin, and cytotoxicity on murine macrophage. Materials and Methods OrthoMTA (BioMTA) was mixed and packed into the human root dentin blocks of 1.5 mm diameter and 5 mm height. Four groups, each of ten roots, were exposed to 10% citric acid (CA), 5% glycolic acid (GA), 17% ethylenediaminetetraacetic acid (EDTA), and saline for five minutes after setting of the OrthoMTA. Vickers surface microhardness of set MTA and dentin was measured before and after exposure to solutions, and compared between groups using one-way ANOVA with Tukey test. The microhardness value of each group was analyzed using student t test. Acid-treated OrthoMTA and dentin was examined by scanning electron microscope (SEM). Cell viability of tested solutions was assessed using WST-8 assay and murine macrophage. Results Three test solutions reduced microhardness of dentin. 17% EDTA demonstrated severe dentinal erosion, significantly reduced the dentinal microhardness compared to 10% CA (p = 0.034) or 5% GA (p = 0.006). 10% CA or 5% GA significantly reduced the surface microhardness of set MTA compared to 17% EDTA and saline (p < 0.001). Acid-treated OrthoMTA demonstrated microporous structure with destruction of globular crystal. EDTA exhibited significantly more cellular toxicity than the other acidic solutions at diluted concentrations (0.2, 0.5, 1.0%). Conclusions Tested acidic solutions reduced microhardness of root dentin. Five minute's application of 10% CA and 5% GA significantly reduced the microhardness of set OrthoMTA with lower cellular cytotoxicity compared to 17% EDTA. PMID:26877986

  7. Thermographic method for evaluation of thermal influence of Nd:YAG laser on a tooth root during sterilization process

    NASA Astrophysics Data System (ADS)

    Madura, H.; Dąbrowski, M.; Dulski, R.; Żmuda, S.; Zaborowski, P.

    2004-12-01

    In this article the use of thermal imaging camera for assessment of thermal effects of Nd:YAG laser irradiation on the root canal wall dentin is described. The aim of this in vitro study was to determine safe conditions of Nd:YAG laser work, i.e. such parameters which do not increase the temperature above levels which can be the cause of undesirable changes in teeth and surrounding tissues. For this study a special test-bed was worked out by authors, which let to simulate conditions similar to those occurring in oral cavity.

  8. Selective excavation of human carious dentin using the nanosecond pulsed laser in 5.8-μm wavelength range

    NASA Astrophysics Data System (ADS)

    Kita, Tetsuya; Ishii, Katsunori; Yoshikawa, Kazushi; Yasuo, Kenzo; Yamamoto, Kazuyo; Awazu, Kunio

    Less-invasive treatment of caries has been needed in laser dentistry. Based on the absorption property of dentin substrates, 6 μm wavelength range shows specific absorptions and promising characteristics for the excavation. In our previous study, 5.8 μm wavelength range was found to be effective for selective excavation of carious dentin and restoration treatment using composite resin from the irradiation experiment with bovine sound and demineralized dentin. In this study, the availability of 5.8 μm wavelength range for selective excavation of human carious dentin was investigated for clinical application. A mid-infrared tunable nanosecond pulsed laser by difference-frequency generation was used for revealing the ablation property of human carious dentin. Irradiation experiments indicated that the wavelength of 5.85 μm and the average power density of 30 W/cm2 realized the selective excavation of human carious dentin, but ablation property was different with respect to each sample because of the different caries progression. In conclusion, 5.8 μm wavelength range was found to be effective for selective excavation of human carious dentin.

  9. Short-pulse Er:YAG laser increases bond strength of composite resin to sound and eroded dentin

    NASA Astrophysics Data System (ADS)

    Cersosimo, Maria Cecília Pereira; Matos, Adriana Bona; Couto, Roberta Souza D.'Almeida; Marques, Márcia Martins; de Freitas, Patricia Moreira

    2016-04-01

    This study evaluated the influence of the irradiation with a short-pulse Er:YAG laser on the adhesion of composite resin to sound and eroded dentin (SD and ED). Forty-six samples of occlusal dentine, obtained from human molars, had half of their surface protected, while the other half was submitted to erosive cycles. Afterward, 23 samples were irradiated with Er:YAG laser, resulting in four experimental groups: SD, sound irradiated dentine (SID-Er:YAG, 50 μs, 2 Hz, 80 mJ, and 12.6 J/cm2), ED, and eroded irradiated dentin (EID-erosion + Er:YAG laser). A self-etching adhesive system was used, and then cylinders of composite resin were prepared. A microshear bond strength test was performed after 24 h storage (n=20). The morphology of SD and ED, with or without Er:YAG laser irradiation, was evaluated under scanning electron microscopy (n=3). Bond strength values (MPa) were subjected to analysis of variance followed by Tukey's test. Statistically significant differences were found among the experimental groups: SD (9.76±3.39 B), SID (12.77±5.09 A), ED (5.12±1.72 D), and EID (7.62±3.39 C). Even though erosion reduces the adhesion to dentin, the surface irradiation with a short-pulse Er:YAG laser increases adhesion to both ED and SD.

  10. Effect of agitation of EDTA with 808-nm diode laser on dentin microhardness.

    PubMed

    Arslan, Hakan; Yeter, Kübra Y; Karatas, Ertugrul; Yilmaz, Cenk B; Ayranci, Leyla B; Ozsu, Damla

    2015-02-01

    The aim of this study is to analyze the effect of agitation of ethylenediaminetetraacetic acid (EDTA) with diode laser at different agitation times on root dentin microhardness. Eighty-four specimens were divided randomly into seven groups, as follows: (1) distilled water, (2) 17% EDTA, (3) EDTA with 60 s ultrasonic agitation, (4) EDTA with 10 s laser agitation, (5) EDTA with 20 s laser agitation, (6) EDTA with 30 s laser agitation, and (7) EDTA with 40 s laser agitation. All of the specimens were irrigated with 5% NaOCl and distilled water except the distilled water group. Microhardness values were calculated before and after the procedures. Statistical analyses were performed using one-way ANOVA and Tukey post hoc tests. Statistically significant differences were determined between the distilled water and other groups. Also, statistically significant differences were observed between EDTA with 40 s laser agitation and EDTA, and EDTA with 10 and 20 s laser agitations. Ultrasonic agitation of EDTA affected microhardness of root dentin similar to EDTA (p > .05). All applications decreased the microhardness of root dentin when compared with distilled water. Agitation of EDTA with diode laser for 40 s caused more reduction in microhardness of root dentin when compared with EDTA. PMID:23793370

  11. Cementum and dentin in hypophosphatasia.

    PubMed

    van den Bos, T; Handoko, G; Niehof, A; Ryan, L M; Coburn, S P; Whyte, M P; Beertsen, W

    2005-11-01

    Hypophosphatasia (HPP) often leads to premature loss of deciduous teeth, due to disturbed cementum formation. We addressed the question to what extent cementum and dentin are similarly affected. To this end, we compared teeth from children with HPP with those from matched controls and analyzed them microscopically and chemically. It was observed that both acellular and cellular cementum formation was affected. For dentin, however, no differences in mineral content were recorded. To explain the dissimilar effects on cementum and dentin in HPP, we assessed pyrophosphate (an inhibitor of mineralization) and the expression/activity of enzymes related to pyrophosphate metabolism in both the periodontal ligament and the pulp of normal teeth. Expression of nucleotide pyrophosphatase phosphodiesterase 1 (NPP1) in pulp proved to be significantly lower than in the periodontal ligament. Also, the activity of NPP1 was less in pulp, as was the concentration of pyrophosphate. Our findings suggest that mineralization of dentin is less likely to be under the influence of the inhibitory action of pyrophosphate than mineralization of cementum. PMID:16246934

  12. Photoactivated rose bengal functionalized chitosan nanoparticles produce antibacterial/biofilm activity and stabilize dentin-collagen

    PubMed Central

    Shrestha, Annie; Hamblin, Michael R.; Kishen, Anil

    2014-01-01

    Treatment of infected teeth presents two major challenges: persistence of the bacterial-biofilm within root canals after treatment and compromised structural integrity of the dentin hard-tissue. In this study bioactive polymeric chitosan nanoparticles functionalized with rose-bengal, CSRBnp was developed to produce antibiofilm effects as well as stabilize structural-integrity by photocrosslinking dentin-collagen. CSRBnp was less toxic to fibroblasts and had significant antibacterial activity even in the presence of bovine serum albumin. CSRBnp exerted antibacterial mechanism by adhering to bacterial cell surface, permeabilizing the membrane and lysing the cells subsequent to photodynamic treatment. Photoactivated CSRBnp resulted in reduced viability of Enterococcus faecalis biofilms and disruption of biofilm structure. Incorporation of CSRBnp and photocrosslinking significantly improved resistance to degradation and mechanical strength of dentin-collagen (p<0.05). The functionalized chitosan nanoparticles provided a single-step treatment of infected root dentin by combining the properties of chitosan and that of photosensitizer to eliminate bacterial-biofilms and stabilize dentin-matrix. PMID:24200522

  13. Dentinal Dysplasia Type I: A Case Report with a 6-Year Followup

    PubMed Central

    Ozer, Sezin; Ozden, Bora; Otan Ozden, Feyza; Gunduz, Kaan

    2013-01-01

    Introduction. Dentin dysplasia is a rare disturbance of dentin formation characterized by normal enamel but atypical dentin formation with abnormal pulpal morphology that is inherited as an autosomal pulpal morphology. Case Presentation. A 7-year-old female who had problems in chewing function was referred to Oral and Maxillofacial Surgery Department at the Faculty of Dentistry in Ondokuz Mayıs University. In the radiographic examination, it was determined that some of the unerupted permanent teeth of the patient had short, blunted, and malformed roots with obliterated pulp chambers, although the bone below the teeth showed well-defined margins. This unusual case of generalized short roots presents a case demonstrating both classic and atypical features of dentinal dysplasia type I (DDI) in the mixed and permanent dentitions. Conclusion. There are still many issues in the diagnosis and management of patients with dentin dysplasia. Early diagnosis, clinical and radiographic findings, as well as treatment of this condition and the initiation of effective preventive strategies may help prevent or delay loss of dentition. PMID:23762649

  14. Effect of cleaning methods on bond strength of self-etching adhesive to dentin

    PubMed Central

    Bronzato, Juliana Delatorre; Cecchin, Doglas; Miyagaki, Daniela Cristina; de Almeida, José Flávio Affonso; Ferraz, Caio Cezar Randi

    2016-01-01

    Aim: The aim of this study was to investigate the influence of cleaning methods to remove zinc oxide-eugenol-based root canal sealer (Endomethasone) on the bond strength of the self-etching adhesive to dentin. Materials and Methods: Twenty crowns of bovine incisors were cut to expose the pulp chamber. A zinc oxide- and eugenol-based sealer was placed for 10 min in contact with the pulp chamber dentin. Specimens were divided into four groups according to the cleaning method of dentin used: G1, no root canal sealer (control); G2, 0.9% sodium chlorite (NaCl); G3, ethanol; and G4, followed by diamond drill. After cleaning, the teeth were restored with composite resin and Clearfil SE Bond. All specimens were sectioned to produce rectangular sticks and dentin/resin interface was submitted to microtensile bond testing. The mean bond strengths were analyzed using ANOVA/Tukey (α = 0.05). Results: G3 and G4 showed bond strengths similar to the G1 (P > 0.05). A significant decrease in the bond strength in the G2 was observed (P < 0.05). G1, G3, and G4, the predominant failure mode was the mixed type. The prevalence of adhesive failure mode was verified in the G2. Conclusion: The cleaning methods affected the bond strength of the self-etching adhesive to dentin differently. PMID:26957789

  15. Shear Bond Strength of an Etch-and-rinse Adhesive to Er:YAG Laser- and/or Phosphoric Acid-treated Dentin

    PubMed Central

    Davari, Abdolrahim; Sadeghi, Mostafa; Bakhshi, Hamid

    2013-01-01

    Background and aims. Er:YAG laser irradiation has been claimed to improve the adhesive properties of dentin; therefore, it has been proposed as an alternative to acid etching. The aim of this in vitro study was to investigate the shear bond strength of an etch-and-rinse adhesive system to dentin surfaces following Er:YAG laser and/or phosphoric acid etching. Materials and methods. The roots of 75 sound maxillary premolars were sectioned below the CEJ and the crowns were embedded in auto-polymerizing acrylic resin with the buccal surfaces facing up. The buccal surfaces were ground using a diamond bur and polished until the dentin was exposed; the samples were randomly divided into five groups (n=15) according to the surface treatment: (1) acid etching; (2) laser etching; (3) laser etching followed by acid etching; (4) acid etching followed by laser etching and (5) no acid etching and no laser etching (control group). Composite resin rods (Point 4, Kerr Co) were bonded to treated dentin surfaces with an etch-and-rise adhesive system (Optibond FL, Kerr Co) and light-cured.After storage for two weeks at 37°C and 100% humidity and then thermocycling, bond strength was measured with a Zwick Universal Testing Machine at a crosshead speed of 1 mm/min. Data was analyzed using parametric and non-parametric tests (P<0.05). Results. Mean shear bond strength for acid etching (20.1±1.8 MPa) and acid+laser (15.6±3.5 MPa) groups were significantly higher than those for laser+acid (15.6±3.5 MPa), laser etching (14.1±3.4 MPa) and control (8.1±2.1 MPa) groups. However, there were no significant differences between acid etching and acid+laser groups, and between laser+acid and laser groups. Conclusion. When the cavity is prepared by bur, it is not necessary to etch the dentin surface by Er:YAG laser following acid etching and acid etching after laser etching. PMID:23875083

  16. Shear Bond Strength of an Etch-and-rinse Adhesive to Er:YAG Laser- and/or Phosphoric Acid-treated Dentin.

    PubMed

    Davari, Abdolrahim; Sadeghi, Mostafa; Bakhshi, Hamid

    2013-01-01

    Background and aims. Er:YAG laser irradiation has been claimed to improve the adhesive properties of dentin; therefore, it has been proposed as an alternative to acid etching. The aim of this in vitro study was to investigate the shear bond strength of an etch-and-rinse adhesive system to dentin surfaces following Er:YAG laser and/or phosphoric acid etching. Materials and methods. The roots of 75 sound maxillary premolars were sectioned below the CEJ and the crowns were embedded in auto-polymerizing acrylic resin with the buccal surfaces facing up. The buccal surfaces were ground using a diamond bur and polished until the dentin was exposed; the samples were randomly divided into five groups (n=15) according to the surface treatment: (1) acid etching; (2) laser etching; (3) laser etching followed by acid etching; (4) acid etching followed by laser etching and (5) no acid etching and no laser etching (control group). Composite resin rods (Point 4, Kerr Co) were bonded to treated dentin surfaces with an etch-and-rise adhesive system (Optibond FL, Kerr Co) and light-cured.After storage for two weeks at 37°C and 100% humidity and then thermocycling, bond strength was measured with a Zwick Universal Testing Machine at a crosshead speed of 1 mm/min. Data was analyzed using parametric and non-parametric tests (P<0.05). Results. Mean shear bond strength for acid etching (20.1±1.8 MPa) and acid+laser (15.6±3.5 MPa) groups were significantly higher than those for laser+acid (15.6±3.5 MPa), laser etching (14.1±3.4 MPa) and control (8.1±2.1 MPa) groups. However, there were no significant differences between acid etching and acid+laser groups, and between laser+acid and laser groups. Conclusion. When the cavity is prepared by bur, it is not necessary to etch the dentin surface by Er:YAG laser following acid etching and acid etching after laser etching. PMID:23875083

  17. Transmission of Curing Light through Moist, Air-Dried, and EDTA Treated Dentine and Enamel

    PubMed Central

    Uusitalo, E.; Varrela, J.; Lassila, L.; Vallittu, P. K.

    2016-01-01

    Objective. This study measured light transmission through enamel and dentin and the effect of exposed dentinal tubules to light propagation. Methods. Light attenuation through enamel and dentin layers of various thicknesses (1 mm, 2 mm, 3 mm, and 4 mm) was measured using specimens that were (1) moist and (2) air-dried (n = 5). Measurements were repeated after the specimens were treated with EDTA. Specimens were transilluminated with a light curing unit (maximum power output 1869 mW/cm2), and the mean irradiance power of transmitting light was measured. The transmission of light through teeth was studied using 10 extracted intact human incisors and premolars. Results. Transmitted light irradiance through 1 mm thick moist discs was 500 mW/cm2 for enamel and 398 mW/cm2 for dentin (p < 0.05). The increase of the specimen thickness decreased light transmission in all groups (p < 0.005), and moist specimens attenuated light less than air-dried specimens in all thicknesses (p < 0.05). EDTA treatment increased light transmission from 398 mW/cm2 to 439 mW/cm2 (1 mm dentin specimen thickness) (p < 0.05). Light transmission through intact premolar was 6.2 mW/cm2 (average thickness 8.2 mm) and through incisor was 37.6 mW/cm2 (average thickness 5.6 mm). Conclusion. Light transmission through enamel is greater than that through dentin, probably reflecting differences in refractive indices and extinction coefficients. Light transmission through enamel, dentin, and extracted teeth seemed to follow Beer-Lambert's law. PMID:27446954

  18. Effect of adhesive hydrophilicity and curing-time on the permeability of resins bonded to water vs. ethanol-saturated acid-etched dentin

    PubMed Central

    Cadenaro, Milena; Breschi, Lorenzo; Rueggeberg, Frederick A.; Agee, Kelli; Di Lenarda, Roberto; Carrilho, Marcela; Tay, Franklin R.; Pashley, David H.

    2009-01-01

    Objective This study examined the ability of five comonomer blends (R1-R5) of methacrylate-based experimental dental adhesives solvated with 10 mass% ethanol, at reducing the permeability of acid-etched dentin. The resins were light-cured for 20, 40 or 60 s. The acid-etched dentin was saturated with water or 100% ethanol. Method Human unerupted third molars were converted into crown segments by removing the occlusal enamel and roots. The resulting crown segments were attached to plastic plates connected to a fluid-filled system for quantifying fluid flow across smear layer-covered dentin, acid-etched dentin and resin-bonded dentin. The degree of conversion of the resins was measured using Fourier transform infrared spectroscopy. Result Application of the most hydrophobic comonomer blend (R1) to water-saturated dentin produced the smallest reductions in dentin permeability (31.9, 44.1 and 61.1% after light-curing for 20, 40 or 60 s respectively). Application of the same blend to ethanol-saturated dentin reduced permeability of 74.1, 78.4 and 81.2%, respectively (p<0.05). Although more hydrophilic resins produced larger reductions in permeability, the same trend of significantly greater reductions in ethanol-saturated dentin over that of water-saturated dentin remained. This result can be explained by the higher solubility of resins in ethanol vs. water. Significance The largest reductions in permeability produced by resins were equivalent but not superior, to those produced by smear layers. Resin sealing of dentin remains a technique-sensitive step in bonding etch-and-rinse adhesives to dentin. PMID:18571228

  19. Contemporary research findings on dentine remineralization.

    PubMed

    Zhong, Bo; Peng, Ce; Wang, Guanhong; Tian, Lili; Cai, Qiang; Cui, Fuzhai

    2015-09-01

    Dentine remineralization is important for the treatment of dentine caries and the bonding durability of dentine and resin materials in clinical practice. Early studies of dentine remineralization were mostly based on the classical pathway of crystallization, which involves large-scale deposition of calcium phosphate crystals on collagen and is achieved in a liquid environment containing mineral ions. Results from these studies were unsatisfactory and not suitable for clinical application because they did not simulate the ordering of hydroxyapatite in the collagen fibres of natural teeth. As studies on collagen type I and non-collagenous proteins have advanced, dentine biomimetic remineralization has become a popular research topic and has shifted to processes involving intrafibrillar remineralization, which is more similar to natural tooth formation. The objective of this review was to summarize current theory and research progress as it relates to dentine remineralization. PMID:23955967

  20. Bactericidal effect of a Nd:YAG laser on Enterococcus faecalis at pulse durations of 15 and 25 ms in dentine depths of 500 and 1,000 μm.

    PubMed

    Franzen, René; Gutknecht, Norbert; Falken, Silke; Heussen, Nicole; Meister, Jörg

    2011-01-01

    The success of endodontic treatment depends on the effective elimination of microorganisms from the root canal, and lasers provide more effective disinfection than conventional treatment using rinsing solutions. The objective of this in vitro study was to determine the bactericidal effect of laser irradiation in dentine of various depths at a wavelength of 1,064 nm and pulse durations of 15 and 25 ms. A total of 90 dentine slices were cut from bovine incisors and divided into two groups (45 slices each) of thickness 500 and 1,000 μm. All were inoculated with a suspension of Enterococcus faecalis (5.07 × 10(9) bacteria/ml). Based on the clinically accepted dose (approximately 300 J/cm(2)), the following laser settings were chosen for this study: 1.75 W, 0.7 Hz for 4 s, three repetitions. The two groups were divided into two subgroups of 15 slices each to be irradiated with pulse durations of 15 and 25 ms. The remaining 15 slices per group were not irradiated to serve as a control. After irradiation, the colony-forming units (CFU) were counted and evaluated. To determine the bactericidal effect of irradiation with different pulse durations, the results in the different groups were compared statistically. For all irradiated subgroups a bactericidal effect was observed at pulse durations of 15 and 25 ms (p=0.0085 and p<0.0001). The corresponding average log kills were 0.29 (15 ms) and 0.52 (25 ms) for 500 μm and 0.15 and 0.3 for 1,000 μm, respectively. The results of this in vitro study showed that Nd:YAG laser irradiation with a pulse duration of 15 ms eliminated an average of 49% and 29% of E. faecalis at dentine depths of 500 μm and 1,000 μm, respectively, and irradiation with a pulse duration of 25 ms eliminated 70% (500 μm) and 50% (1,000 μm). However, these values are lower than those achieved with the established protocol using microsecond pulses. PMID:20809081

  1. Dielectric response of the human tooth dentine

    NASA Astrophysics Data System (ADS)

    Leskovec, J.; Filipič, C.; Levstik, A.

    2005-07-01

    Dielectric properties of tooth dentine can be well described by the model which was developed for the dielectric response to hydrating porous cement paste. It is shown that the normalized dielectric constant and the normalized specific conductivity are proportional to the model parameters ɛ and σv, indicating the deposition of AgCl in the dentine tubules during the duration of the precipitation. The fractal dimension of the tooth dentine was determined by dielectric spectroscopy.

  2. Treatment of dentinal tubules by Nd:YAG laser

    NASA Astrophysics Data System (ADS)

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

    2005-08-01

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

  3. Hereditary dentine disorders: dentinogenesis imperfecta and dentine dysplasia

    PubMed Central

    Barron, Martin J; McDonnell, Sinead T; MacKie, Iain; Dixon, Michael J

    2008-01-01

    The hereditary dentine disorders, dentinogenesis imperfecta (DGI) and dentine dysplasia (DD), comprise a group of autosomal dominant genetic conditions characterised by abnormal dentine structure affecting either the primary or both the primary and secondary dentitions. DGI is reported to have an incidence of 1 in 6,000 to 1 in 8,000, whereas that of DD type 1 is 1 in 100,000. Clinically, the teeth are discoloured and show structural defects such as bulbous crowns and small pulp chambers radiographically. The underlying defect of mineralisation often results in shearing of the overlying enamel leaving exposed weakened dentine which is prone to wear. Currently, three sub-types of DGI and two sub-types of DD are recognised but this categorisation may change when other causative mutations are found. DGI type I is inherited with osteogenesis imperfecta and recent genetic studies have shown that mutations in the genes encoding collagen type 1, COL1A1 and COL1A2, underlie this condition. All other forms of DGI and DD, except DD-1, appear to result from mutations in the gene encoding dentine sialophosphoprotein (DSPP), suggesting that these conditions are allelic. Diagnosis is based on family history, pedigree construction and detailed clinical examination, while genetic diagnosis may become useful in the future once sufficient disease-causing mutations have been discovered. Differential diagnoses include hypocalcified forms of amelogenesis imperfecta, congenital erythropoietic porphyria, conditions leading to early tooth loss (Kostmann's disease, cyclic neutropenia, Chediak-Hegashi syndrome, histiocytosis X, Papillon-Lefevre syndrome), permanent teeth discolouration due to tetracyclines, Vitamin D-dependent and vitamin D-resistant rickets. Treatment involves removal of sources of infection or pain, improvement of aesthetics and protection of the posterior teeth from wear. Beginning in infancy, treatment usually continues into adulthood with a number of options including

  4. Role of microstructure on fracture of dentin.

    PubMed

    An, Bingbing; Wagner, H Daniel

    2016-06-01

    Dentin possesses unique hierarchical structure, which has a significant influence on the mechanical properties. Understanding the relationship between structure and mechanical properties of dentin is essential for preventing and curing oral diseases, as well as, potentially for developing man-made engineering materials with superior mechanical performance. In this study, the effect of the two-layered structure, where hard peritubular dentin (PTD) containing dentin tubules are embedded in soft intertubular dentin (ITD), on the fracture behavior of dentin is investigated. A numerical model is developed, in which PTD cracking, ITD cracking and the debonding of the interface between PTD and ITD are all taken into account. Numerical simulations reveal that PTD fracture and interface debonding are the major failure mechanisms, which are consistent with experimental observation. It is identified that the cohesive strength and critical separation of interface are the key parameters controlling which of the mechanisms is active. The low cohesive strength of interface and small critical separation of interface can lead to interface debonding, while the large cohesive strength and critical separation give rise to PTD fracture. In addition, it is found that large volume fraction of dentin tubules and small volume fraction of PTD can enhance the toughness of dentin, which provides a new insight into the degraded mechanical properties of old dentin. PMID:27018833

  5. Dentine and enamel bonding agents.

    PubMed

    Bowen, R L; Tung, M S; Blosser, R L; Asmussen, E

    1987-09-01

    Previous studies have shown that sequential use of aqueous FO (ferric oxalate containing a small concentration of HNO3), acetone solutions of NPG (N-phenylglycine), and PMDM (the reaction product of pyromellitic dianhydride and 2-hydroxyethylmethacrylate) yields strong adhesive bonding of composite resins to both dentine and enamel. The purpose of this study was to determine if aluminum ions could be substituted for ferric ions and if the procedure could be simplified. Aqueous solutions containing aluminum oxalate and aluminum nitrate, followed in sequence by acetone solutions of NPG and PMDM, gave strong tensile adhesive bond strengths between a composite and extracted human teeth. Comparable values have been obtained with FO, NPG and PMDM. Aluminum oxalate solutions containing no nitrate gave lower bond strengths, as was the case with FO. Aqueous solutions of acidified aluminum oxalate can dissolve NPG, thereby allowing a simplification of the procedure. Tested for comparison, commercially available dentine bonding agents gave lower average bond strengths on dentine than did some of the experimental materials. PMID:3316044

  6. The effect of CO2 laser irradiation plus fluoride dentifrice on the inhibition of secondary caries on root surfaces adjacent to glass ionomer cement or composite resin restorations

    NASA Astrophysics Data System (ADS)

    Rodrigues, S. R.; Moraes, M.; Hanashiro, F. S.; Youssef, M. N.; Brugnera Junior, A.; Nobre-dos-Santos, M.; de Souza-Zaroni, W. C.

    2016-02-01

    Although the cariostatic effects of CO2 laser on the root surface have been shown, there is scarce information regarding its effects on root secondary caries. The objective of this research was to investigate the effect of the association of CO2 laser and a fluoride dentifrice on the inhibition of secondary caries on root surfaces adjacent to composite-resin or glass-ionomer-cement restorations. Dental blocks of human roots were divided into two groups: composite resin (CR) or glass ionomer cement (GIC). Subsequently, the blocks were divided into four subgroups (n  =  10): C, non-fluoride dentifrice; FD, fluoride dentifrice; L, CO2 laser with an energy density of 6.0 J cm-2  +  non-fluoride dentifrice; and L  +  FD, CO2 laser  +  fluoride dentifrice. The blocks were subjected to pH cycling to simulate a high cariogenic challenge. Dental demineralization around the restorations was quantified by microhardness analysis. The results were subjected to analysis of variance (ANOVA) and the Tukey-Kramer test (p  ⩽  0.05). As for mineral loss, it can be observed that all the groups that were treated with a fluoride dentifrice and laser, used alone or not, were statistically similar and superior to the RC-C group. It was concluded that CO2 laser irradiation and a fluoride dentifrice used alone or combined with each other are efficient surface treatments for preventing secondary root caries, regardless of the restorative material used.

  7. Evaluation of the dentinal wall adaptation ability of MTA Fillapex using stereo electron microscope

    PubMed Central

    Demiriz, Levent; Koçak, Mustafa Murat; Koçak, Sibel; Sağlam, Baran Can; Türker, Sevinç Aktemur

    2016-01-01

    Background: An ideal root canal obturation requires a complete dentinal wall adaptation of sealer and Gutta-percha combinations without any gap formations. Aims: The aim of the study was to evaluate the dentinal wall adaptation ability of MTA Fillapex root canal sealer using stereo electron microscope (SEM). Methods: Twenty-four, single-rooted, human maxillary incisor teeth were used. All canals were prepared with a rotary nickel–titanium (Ni–Ti) instrument to a size F3 file. Teeth divided into two equal groups and one of the experimental groups was filled with AH Plus, and the other group was filled with MTA Fillapex using Gutta-percha single cone as a core material. The roots were prepared for SEM evaluation, and serial scanning electron photomicrographs were taken at ×50, ×100, ×500, and ×1000 magnifications. The gaps between the root canal sealer and canal walls were detected and measured in coronal, middle, and apical thirds. For each section, the highest value among the detected gap formations was recorded. Statistical Analysis: Mann–Whitney U-test, Freidman, and Wilcoxon tests were used. Results: The statistical analysis showed no significant difference between two sealers in terms of gap formation (P > 0.05). Conclusions: MTA Fillapex has a similar dentinal wall adaptation ability as AH Plus does. PMID:27217633

  8. In vitro investigation of intra-canal dentine-laser beam interaction aspects: I. Evaluation of ablation capability (ablation rate and efficiency).

    PubMed

    Minas, Nova Hambersom; Meister, Joerg; Franzen, Rene; Gutknecht, Norbert; Lampert, Friedrich

    2010-11-01

    The aim of this study was to determine the amount of intra-canal dentine removed with an erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser using different endodontic tips and different power settings. Ninety intact extracted bovine teeth were selected as samples. After sectioning the roots and preparing the testing cylinders, we divided the samples into three main groups (A, B, C), with further subdivision of each group to be irradiated with three different powers (1500 mW, 1750 mW and 2000 mW). An Er,Cr:YSGG laser system (2.78 microm, 140 micros, 20 Hz and 65% water to 35% air ratio) was used for irradiation, and the loss of intra-canal dentine mass was calculated by the difference between the initial and final sample masses. Data were analysed with Kolmogorov-Smirnov, analysis of variance (ANOVA) and Tukey tests. At a significance level of alpha = 1%, the results showed statistically significant differences (P < 0.0001) between different tip groups, regarding both the ablation rate and the ablation efficiency criteria. With regard to the three irradiation power settings, statistically significant difference were recorded only between groups C and A, for the ablation rate criteria. The intra-canal ablation ability of the Er,Cr:YSGG laser improved with increasing power and/or tip diameter. The latter exhibited a stronger influence on ablation rate and efficiency. Laser intra-canal ablation is an important addition to the field of endodontics; nevertheless, further investigations and system improvements are required. PMID:19636663

  9. Challenges of stem cell-based pulp and dentin regeneration: a clinical perspective

    PubMed Central

    HUANG, GEORGE T.-J.; AL-HABIB, MEY; GAUTHIER, PHILIPPE

    2013-01-01

    There are two types of approaches to regenerate tissues: cell-based and cell-free. The former approach is to introduce exogenous cells into the host to regenerate tissues, and the latter is to use materials other than cells in an attempt to regenerate tissues. There has been a significant advancement in stem cell-based pulp and dentin regeneration research in the past few years. Studies in small and large animals have demonstrated that pulp/dentin-like tissues can be regenerated partially or completely in the root canal space with apical openings of 0.7-3.0 mm using dental pulp stem cells, including stem cells from apical papilla (SCAP) and subpopulations of pulp stem cells. Bone marrow mesenchymal stem cells (BMMSCs) and adipose tissue-derived MSCs (ADMSCs) have also been shown to regenerate pulp-like tissue. In contrast, the cell-free approach has not produced convincing evidence on pulp regeneration. However, one crucial concept has not been considered nor defined in the field of pulp/dentin regeneration and that is the critical size defect of dentin and pulp. Without such consideration and definition, it is difficult to predict or anticipate the extent of cell-free pulp regeneration that would occur. By reasoning, cell-free therapy is unlikely to regenerate an organ/tissue after total loss. Similarly, after a total loss of pulp, it is unlikely to regenerate without using exogenously introduced cells. A cell homing approach may provide a limited amount of tissue regeneration. Although stem cell-based pulp/dentin regeneration has shown great promise, clinical trials are difficult to launch at present. This article will address several issues that challenge and hinder the clinical applications of pulp/dentin regeneration which need to be overcome before stem cell-based pulp/dentin regeneration can occur in the clinic. PMID:23914150

  10. Degradation in the dentin-composite interface subjected to multi-species biofilm challenges.

    PubMed

    Li, Y; Carrera, C; Chen, R; Li, J; Lenton, P; Rudney, J D; Jones, R S; Aparicio, C; Fok, A

    2014-01-01

    Oral biofilms can degrade the components in dental resin-based composite restorations, thus compromising marginal integrity and leading to secondary caries. This study investigates the mechanical integrity of the dentin-composite interface challenged with multi-species oral biofilms. While most studies used single-species biofilms, the present study used a more realistic, diverse biofilm model produced directly from plaques collected from donors with a history of early childhood caries. Dentin-composite disks were made using bovine incisor roots filled with Z100(TM) or Filtek(TM) LS (3M ESPE). The disks were incubated for 72 h in paired CDC biofilm reactors, using a previously published protocol. One reactor was pulsed with sucrose, and the other was not. A sterile saliva-only control group was run with sucrose pulsing. The disks were fractured under diametral compression to evaluate their interfacial bond strength. The surface deformation of the disks was mapped using digital image correlation to ascertain the fracture origin. Fracture surfaces were examined using scanning electron microscopy/energy-dispersive X-ray spectroscopy to assess demineralization and interfacial degradation. Dentin demineralization was greater under sucrose-pulsed biofilms, as the pH dropped <5.5 during pulsing, with LS and Z100 specimens suffering similar degrees of surface mineral loss. Biofilm growth with sucrose pulsing also caused preferential degradation of the composite-dentin interface, depending on the composite/adhesive system used. Specifically, Z100 specimens showed greater bond strength reduction and more frequent cohesive failure in the adhesive layer. This was attributed to the inferior dentin coverage by Z100 adhesive, which possibly led to a higher level of chemical and enzymatic degradation. The results suggested that factors other than dentin demineralization were also responsible for interfacial degradation. A clinically relevant in vitro biofilm model was therefore

  11. Dentin: a dynamic substrate--a review.

    PubMed

    Pashley, D H

    1989-03-01

    The structure of dentin is unusual in that the number and size of its tubules changes as one moves from the periphery toward the pulp chamber. Near the pulp, the tubules are very close together and the water content of this deep dentin is high. Near the enamel, the tubules are far apart, occupying less than 1% of the surface area. When enamel or dentin is cut, the surface becomes covered by an adherent layer of cutting debris called the smear layer. Its composition presumably reflects the composition of the underlying dentin. It is only about 1 micron thick but its presence modifies the function of the dentin a great deal. It lowers dentin permeability and therefore can be regarded as protective. However, it masks the underlying dentin and hence interferes with attempts to bond dental materials directly to dentin. If it is removed, the dentin becomes much more permeable and fluid shifts across the open tubules can cause sensitivity in vivo. As smear layers are very acid-labile, they often dissolve in oral fluids. Several attempts have been made to replace smear layers with acid resistant structures that accomplish the same function. Smear layer structure is being studied by using both scanning electron microscopy as well as electronic particle sizing equipment. The close adaptation of dental materials to smear layers and to underlying dentin is currently an area of very active research. Removal of smear layers increases adaptation and bonding strength but may increase the incidence of pulpal inflammation if the bonding is not uniform or permanent. The dynamics of dentin are just beginning to be understood. PMID:2662395

  12. Chelating and antibacterial properties of chitosan nanoparticles on dentin

    PubMed Central

    Bramante, Clovis Monteiro; Duarte, Marco Antonio Hungaro; de Moura, Marcia Regina; Aouada, Fauze Ahmad; Kishen, Anil

    2015-01-01

    Objectives The use of chitosan nanoparticles (CNPs) in endodontics is of interest due to their antibiofilm properties. This study was to investigate the ability of bioactive CNPs to remove the smear layer and inhibit bacterial recolonization on dentin. Materials and Methods One hundred bovine dentin sections were divided into five groups (n = 20 per group) according to the treatment. The irrigating solutions used were 2.5% sodium hypochlorite (NaOCl) for 20 min, 17% ethylenediaminetetraacetic acid (EDTA) for 3 min and 1.29 mg/mL CNPs for 3 min. The samples were irrigated with either distilled water (control), NaOCl, NaOCl-EDTA, NaOCl-EDTA-CNPs or NaOCl-CNPs. After the treatment, half of the samples (n = 50) were used to assess the chelating effect of the solutions using portable scanning electronic microscopy, while the other half (n = 50) were infected intra-orally to examine the post-treatment bacterial biofilm forming capacity. The biovolume and cellular viability of the biofilms were analysed under confocal laser scanning microscopy. The Kappa test was performed for examiner calibration, and the non-parametric Kruskal-Wallis and Dunn tests (p < 0.05) were used for comparisons among the groups. Results The smear layer was significantly reduced in all of the groups except the control and NaOCl groups (p < 0.05). The CNPs-treated samples were able to resist biofilm formation significantly better than other treatment groups (p < 0.05). Conclusions CNPs could be used as a final irrigant during root canal treatment with the dual benefit of removing the smear layer and inhibiting bacterial recolonization on root dentin. PMID:26295022

  13. Effects of polar solvents and adhesive resin on the denaturation temperatures of demineralised dentine matrices

    PubMed Central

    Armstrong, Steven R.; Jessop, Julie L.P.; Winn, Erik; Tay, Franklin R.; Pashley, David H.

    2010-01-01

    SUMMARY Objectives To measure the denaturation temperature (Td) of demineralised dentine matrix as a function of infiltration with water vs polar solvents vs adhesive resins. Methods Small disks of normal dentine were completely demineralised in 0.5 M EDTA. Dried demineralised specimens were placed in water, methanol, ethanol, acetone, η-butanol or HEMA. Additional specimens were infiltrated with Prime & Bond NT and polymerised. All specimens sealed in high pressure pans and scanned using differential scanning calorimetry (DSC). Results Demineralised dentine saturated with water showed a Td of 65.6°C that increased with saturation by methanol, ethanol, acetone, η-butanol or HEMA to 148.5°C. These increases in Td were inversely related to the molar concentration of the solvents and to their Hoy’s solubility parameter for hydrogen bonding (δh, p<0.01), as well as directly related to the cube root of their molecular weights (p<0.001). The presence of adhesive resins also increased the Td of demineralised matrices to even higher values depending if the resin bonded dentine was measured after 24 h of water storage (166.8°C) or dry (172.7°C) storage. Conclusions Solvents and monomers with low δh values (i.e. 100% HEMA) increase the Td of demineralized dentin above that produced by solvents with higher δh values such as methanol and water. PMID:18022750

  14. Micro energy-dispersive x-ray fluorescence spectrometry study of dentin coating with nanobiomaterials

    NASA Astrophysics Data System (ADS)

    Soares, Luís. Eduardo Silva; Nahorny, Sídnei; Marciano, Fernanda Roberta; Zanin, Hudson; Lobo, Anderson de Oliveira

    2015-06-01

    New biomaterials such as multi-walled carbon nanotubes oxide/graphene oxide (MWCNTO/GO), nanohydroxyapatite (nHAp) and combination of them together or not to acidulated phosphate fluoride gel (F) have been tested as protective coating before root dentin erosion. Fourteen bovine teeth were cleaned, polished, divided into two parts (n=28) and assigned to seven groups: (Control) - without previous surface treatment; F treatment; nHAp; MWCNTO/GO; F+nHAp; F+MWCNTO/GO and F+MWCNTO/GO/nHAp composites. Each sample had two sites of pre-treatments: acid etched area and an area without treatment. After the biomaterials application, the samples were submitted to six cycles (demineralization: orange juice, 10 min; remineralization: artificial saliva, 1 h). Micro energy-dispersive X-ray fluorescence spectrometry (μ-EDXRF) mapping area analyses were performed after erosive cycling on both sites (n=84). μ-EDXRF mappings showed that artificial saliva and MWCNTO/GO/nHAp/F composite treatments produced lower dentin demineralization than in the other groups. Exposed dentin tubules allowed better interaction of nanobiomaterials than in smear layer covered dentin. Association of fluoride with other biomaterials had a positive influence on acid etched dentin. MWCNTO/GO/nHAp/F composite treatment resulted in levels of demineralization similar to the control group.

  15. Bioinspired toughening mechanism: lesson from dentin.

    PubMed

    An, Bingbing; Zhang, Dongsheng

    2015-08-01

    Inspired by the unique microstructure of dentin, in which the hard peritubular dentin surrounding the dentin tubules is embedded in the soft intertubular dentin, we explore the crack propagation in the bioinspired materials with fracture process zone possessing a dentin-like microstructure, i.e. the composite structure consisting of a soft matrix and hard reinforcements with cylindrical voids. A micromechanical model under small-scale yielding conditions is developed, and numerical simulations are performed, showing that the rising resistant curve (R-curve) is observed for crack propagation caused by the plastic collapse of the intervoid ligaments in the fracture process zone. The dentin-like microstructure in the fracture process zone exhibits enhanced fracture toughness, compared with the case of voids embedded in the homogeneous soft matrix. Further computational simulations show that the dentin-like microstructure can retard void growth, thereby promoting fracture toughness. The typical fracture mechanism of the bioinspired materials with fracture process zone possessing the dentin-like structure is void by void growth, while it is the multiple void interaction in the case of voids in the homogeneous matrix. Based on the results, we propose a bioinspired material design principle, which is that the combination of a hard inner material encompassing voids and a soft outer material in the fracture process zone can give rise to exceptional fracture toughness, achieving damage tolerance. It is expected that the proposed design principle could shed new light on the development of novel man-made engineering materials. PMID:26158322

  16. Thermal effects and morphological aspects of varying Er:YAG laser energy on demineralized dentin removal: an in vitro study.

    PubMed

    Raucci-Neto, Walter; Raquel Dos Santos, Carla; Augusto de Lima, Fabrício; Pécora, Jesus Djalma; Bachmann, Luciano; Palma-Dibb, Regina Guenka

    2015-05-01

    The aim of this study was to evaluate thermal changes, dentin ablation removal capacity, and morphological aspects of sound and demineralized human dentin surface irradiated with different output energies of an erbium: yttrium-aluminium-garnet (Er:YAG) laser. Eighty sound human tooth specimens were assigned into two groups: demineralized dentin and sound dentin (control group). The dentin groups were subdivided into four subgroups (n = 10) according to the irradiation energy used (120, 160, 200, or 250 mJ) at a constant frequency level of 6 Hz, in focused mode, and under refrigeration. Quantitative analysis of the sound and carious dentin ablation was performed using light microscopy (LM) by measuring (mm) the remaining demineralized tissue with the Axion Vision™ software. Qualitative analysis was performed using the images obtained with a scanning electron microscope (SEM), and the temperature increase was recorded with an infrared digital thermometer. The Er:YAG laser promoted a gradual increase in temperature for all groups, and no difference was observed between the sound and demineralized dentin. The groups of 200 and 250 mJ showed the highest values, yet a variation in temperature did not exceed 5 °C. The energy output of 120 mJ selectively removed demineralized tissue when compared to 250 mJ, while also providing more regular surfaces in the cavity preparation. It was concluded that the temperature increase during sound and demineralized dentin removal had a strong positive correlation with the Er:YAG laser energy level output. However, the higher energies used did not present selectivity to the demineralized tissue, and the parameters used did not cause an increase in temperature over 5 °C. PMID:24756325

  17. Cysteine Cathepsins in Human Carious Dentin

    PubMed Central

    Nascimento, F.D.; Minciotti, C.L.; Geraldeli, S.; Carrilho, M.R.; Pashley, D.H.; Tay, F.R.; Nader, H.B.; Salo, T.; Tjäderhane, L.; Tersariol, I.L.S.

    2011-01-01

    Matrix metalloproteinases (MMPs) are important in dentinal caries, and analysis of recent data demonstrates the presence of other collagen-degrading enzymes, cysteine cathepsins, in human dentin. This study aimed to examine the presence, source, and activity of cysteine cathepsins in human caries. Cathepsin B was detected with immunostaining. Saliva and dentin cysteine cathepsin and MMP activities on caries lesions were analyzed spectrofluorometrically. Immunostaining demonstrated stronger cathepsins B in carious than in healthy dentin. In carious dentin, cysteine cathepsin activity increased with increasing depth and age in chronic lesions, but decreased with age in active lesions. MMP activity decreased with age in both active and chronic lesions. Salivary MMP activities were higher in patients with active than chronic lesions and with increasing lesion depth, while cysteine cathepsin activities showed no differences. The results indicate that, along with MMPs, cysteine cathepsins are important, especially in active and deep caries. PMID:21248362

  18. Dentine caries: take it or leave it?

    PubMed

    Banerjee, A; Watson, T F; Kidd, E A

    2001-04-01

    In modern dentistry the primary aim when excavating carious dentine is to eradicate only the highly infected, irreversibly demineralised and denatured biomass in order to allow effective restoration of the cavity, restoration of the surface anatomy of the tooth and to prevent disease progression. However, the boundary between this superficial zone of dentine requiring excavation and the deeper, affected but repairable tissue is not always obvious either in the clinic or in the research laboratory. The inherent subjectivity in detecting this excavation boundary can result in clinically significant differences in the quality and quantity of dentine removed by different operators and makes the in vitro comparison of newer excavation techniques more difficult. This article discusses the rationale behind carious dentine excavation and the criteria available to the dentist, both clinical and laboratory, to help identify the dentine requiring removal. PMID:11436234

  19. Dentine caries: take it or leave it?

    PubMed

    Banerjee, A; Watson, T F; Kidd, E A

    2000-01-01

    In modern dentistry the primary aim when excavating carious dentine is to eradicate only the highly infected, irreversibly demineralized and denatured biomass in order to allow effective restoration of the cavity, restoration of the surface anatomy of the tooth and to prevent disease progression. However, the boundary between this superficial zone of dentine requiring excavation and the deeper, affected but repairable tissue is not always obvious either in the clinic or in the research laboratory. The inherent subjectivity in detecting this excavation boundary can result in clinically significant differences in the quality and quantity of dentine removed by different operators and makes the in vitro comparison of newer excavation techniques more difficult. This article discusses the rationale behind carious dentine excavation and the criteria available to the dentist, both clinical and laboratory, to help identify the dentine requiring removal. PMID:11218463

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

    PubMed

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

    2002-01-01

    The hybrid layer created in caries-affected dentin has not been fully elucidated and may influence bond durability. This study investigated the nanoleakage patterns of caries-affected dentin after excavation with Carisolv or conventional instruments treated with one of three adhesive systems. Flat occlusal dentin surfaces, including carious lesions, were prepared from extracted human molars and finished with wet 600-grit silicon carbide paper. Carious dentin was removed with Carisolv or round steel burs in conjunction with Caries Detector. PermaQuik, Single Bond or One-Up Bond F was bonded to the excavated dentin surfaces and adjacent flat occlusal surfaces and it was covered with Silux Plus resin-based composite. After 24-hour storage in 37 degrees C water, the bonded interfaces were polished to remove flash, and the surrounding tooth surfaces were coated with nail varnish. Specimens were immersed in 50% (w/v) silver nitrate solution for 24 hours, exposed to photo developing solution for eight hours, then sectioned longitudinally through the bonded, excavated dentin or "normal" dentin surfaces. The sectioned surfaces were polished, carbon coated and observed in a Field Emission-SEM using back scattered electrons. Silver deposition occurred along the base of the hybrid layer for all specimens. However, Single Bond showed a greater density of silver deposition in the caries-affected dentin compared with normal dentin. PermaQuik had a thicker hybrid layer in caries-affected dentin than normal dentin. One-Up Bond F exhibited a thin hybrid layer in normal dentin, but the hybrid layer was often difficult to detect in caries-affected dentin. PMID:12120777

  1. Effect of dentin dehydration and composite resin polymerization mode on bond strength of two self-etch adhesives

    PubMed Central

    Samimi, Pooran; Alizadeh, Mehdi; Shirban, Farinaz; Davoodi, Amin; Khoroushi, Maryam

    2016-01-01

    Background: Dual-cured composite resins are similar to self-cured composite resins in some of their clinical applications due to inadequate irradiation, lack of irradiation, or delayed irradiation. Therefore, incompatibility with self-etch adhesives (SEAs) should be taken into account with their use. On the other, the extent of dentin dehydration has a great role in the quality of adhesion of these resin materials to dentin. The aim of this study was to investigate the effect of dentin dehydration and composite resin polymerization mode on bond strength of two SEAs. Materials and Methods: A total of 120 dentinal specimens were prepared from extracted intact third molars. Half of the samples were dehydrated in ethanol with increasing concentrations. Then Clearfil SE Bond (CSEB) and Prompt L-Pop (PLP) adhesives were applied in the two groups. Cylindrical composite resin specimens were cured using three polymerization modes: (1) Immediate light-curing, (2) delayed light-curing after 20 min, and (3) self-curing. Bond strength was measured using universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed with two-way ANOVA and Duncan post hoc tests. Statistical significance was defined at P < 0.05. Results: There were no significant differences for CSEB subgroups with hydrated and dehydrated dentin samples between the three different curing modes (P > 0.05). PLP showed significant differences between subgroups with the lowest bond strength in hydrated dentin with delayed light-curing and self-cured mode of polymerization. Conclusion: Within the limitations of this study, a delay in composite resin light-curing or using chemically cured composite resin had a deleterious effect on dentin bond strength of single-step SEAs used in the study. PMID:27041894

  2. Selective excavation of human carious dentin using a nanosecond pulsed laser with a wavelength of 5.85 μm

    NASA Astrophysics Data System (ADS)

    Kita, Tetsuya; Ishii, Katsunori; Yoshikawa, Kazushi; Yasuo, Kenzo; Yamamoto, Kazuyo; Awazu, Kunio

    2013-06-01

    Less-invasive treatment of caries has been needed in laser dentistry. Based on the absorption property of dentin substrates, 6 μm wavelength range shows specific absorptions and promising characteristics for the excavation. In our previous study, 5.8 μm wavelength range was found to be effective for selective excavation of carious dentin and restoration treatment using composite resin from the irradiation experiment with bovine sound and demineralized dentin. In this study, the availability of 5.8 μm wavelength range for selective excavation of human carious dentin was investigated for clinical application. A mid-infrared tunable nanosecond pulsed laser by difference-frequency generation was used for revealing the ablation property of human carious dentin. Irradiation experiments indicated that the wavelength of 5.85 μm and the average power density of 30 W/cm2 realized the selective excavation of human carious dentin, but ablation property was different with respect to each sample because of the different caries progression. In conclusion, the wavelength of 5.85 μm could realize the selective excavation of human carious dentin, but it was necessary to evaluate the stage of caries progression in order to control the ablation property.

  3. Neural crest deletion of Dlx3 leads to major dentin defects through down-regulation of Dspp.

    PubMed

    Duverger, Olivier; Zah, Angela; Isaac, Juliane; Sun, Hong-Wei; Bartels, Anne K; Lian, Jane B; Berdal, Ariane; Hwang, Joonsung; Morasso, Maria I

    2012-04-01

    During development, Dlx3 is expressed in ectodermal appendages such as hair and teeth. Thus far, the evidence that Dlx3 plays a crucial role in tooth development comes from reports showing that autosomal dominant mutations in DLX3 result in severe enamel and dentin defects leading to abscesses and infections. However, the normal function of DLX3 in odontogenesis remains unknown. Here, we use a mouse model to demonstrate that the absence of Dlx3 in the neural crest results in major impairment of odontoblast differentiation and dentin production. Mutant mice develop brittle teeth with hypoplastic dentin and molars with an enlarged pulp chamber and underdeveloped roots. Using this mouse model, we found that dentin sialophosphoprotein (Dspp), a major component of the dentin matrix, is strongly down-regulated in odontoblasts lacking Dlx3. Using ChIP-seq, we further demonstrate the direct binding of Dlx3 to the Dspp promoter in vivo. Luciferase reporter assays determined that Dlx3 positively regulates Dspp expression. This establishes a regulatory pathway where the transcription factor Dlx3 is essential in dentin formation by directly regulating a crucial matrix protein. PMID:22351765

  4. Neural Crest Deletion of Dlx3 Leads to Major Dentin Defects through Down-regulation of Dspp*

    PubMed Central

    Duverger, Olivier; Zah, Angela; Isaac, Juliane; Sun, Hong-Wei; Bartels, Anne K.; Lian, Jane B.; Berdal, Ariane; Hwang, Joonsung; Morasso, Maria I.

    2012-01-01

    During development, Dlx3 is expressed in ectodermal appendages such as hair and teeth. Thus far, the evidence that Dlx3 plays a crucial role in tooth development comes from reports showing that autosomal dominant mutations in DLX3 result in severe enamel and dentin defects leading to abscesses and infections. However, the normal function of DLX3 in odontogenesis remains unknown. Here, we use a mouse model to demonstrate that the absence of Dlx3 in the neural crest results in major impairment of odontoblast differentiation and dentin production. Mutant mice develop brittle teeth with hypoplastic dentin and molars with an enlarged pulp chamber and underdeveloped roots. Using this mouse model, we found that dentin sialophosphoprotein (Dspp), a major component of the dentin matrix, is strongly down-regulated in odontoblasts lacking Dlx3. Using ChIP-seq, we further demonstrate the direct binding of Dlx3 to the Dspp promoter in vivo. Luciferase reporter assays determined that Dlx3 positively regulates Dspp expression. This establishes a regulatory pathway where the transcription factor Dlx3 is essential in dentin formation by directly regulating a crucial matrix protein. PMID:22351765

  5. Cervical microleakage in root canals treated with Er:YAG and Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    Sponchiado, Emilio C., Jr.; Azevedo, Lidiany K.; Marchesan, Melissa; Brugnera, Aldo, Jr.; Silva-Sousa, Yara T.; Alfredo, Edson; Sousa Neto, Manoel D.

    2005-03-01

    Cervical microleakage was evaluated in sealed root canals previously treated with Er:YAG and Nd:YAG lasers. Ninety-two single-rooted maxillary human canines were prepared with the crown-down technique and irrigated with distilled and deionized water. The samples were distributed randomly into 9 groups of 10 teeth each. One tooth was used as a positive control and one as a negative control. In group I, 1.2 ml of EDTAC was applied during 5 min. In groups II to V, radicular dentine was irradiated with Er:YAG laser (Opus 20, Opus Dent, Israel) at the following parameters: 200 mJ and 8 Hz, 200 mJ and 16 Hz, 400 mJ and 8 Hz, or 400 mJ and 16Hz, respectively, for 60 s. In groups VI to IX, radicular dentine was irradiated with Nd:YAG laser (Fotona Medical Lasers, Slovenia) at 10 Hz and 1 W, 10 Hz and 2 W, 15 Hz and 1 W, or 15 Hz and 2 W, respectively, for 60 s. The canals were then sealed by the lateral condensation technique with an epoxy resin-based sealer. The roots were immersed in India ink for 15 days and then cleared to visualize the level of cervical microleakage with a measurement microscope. The results were evaluated by the Kruskal-Wallis test, which showed no statistical significance (p>0.01) for parameter variations of the Er:YAG laser when compared to the control group. However, the increase in frequency and potency for Nd:YAG laser decreased the microleakage when compared to the control group.

  6. [An in vitro trial of the chemomechanical treatment of root caries: the Caridex system].

    PubMed

    Romand-Roeloffs, N; Roh, S; Holz, J

    1991-01-01

    This study was aimed to verify the debridement potential of the Caridex system against radicular cervical caries. 14 freshly extracted teeth with cervical caries were split and the fragments were freed from the dentinal caries using three methods: root planning (with a white stone), conventional excavation with a bur (tungsten) and the Caridex system. The results show that the Caridex system can partially dissolve the decayed dentin but leaves behind smeared surfaces as well as part of dentin infiltrated by bacteria. The root planning treatment smears the dentinal surface and thus blocks the tubules which also appeared to be infiltrated with bacteria. The excavation method allowed for a complete elimination of the decayed dentinal tissue down to the hypermineralized zone. PMID:2020836

  7. Regeneration of dental pulp/dentine complex with a three-dimensional and scaffold-free stem-cell sheet-derived pellet.

    PubMed

    Na, Sijia; Zhang, Hao; Huang, Fang; Wang, Weiqi; Ding, Yin; Li, Dechao; Jin, Yan

    2016-03-01

    Dental pulp/dentine complex regeneration is indispensable to the construction of biotissue-engineered tooth roots and represents a promising approach to therapy for irreversible pulpitis. We used a tissue-engineering method based on odontogenic stem cells to design a three-dimensional (3D) and scaffold-free stem-cell sheet-derived pellet (CSDP) with the necessary physical and biological properties. Stem cells were isolated and identified and stem cells from root apical papilla (SCAPs)-based CSDPs were then fabricated and examined. Compact cell aggregates containing a high proportion of extracellular matrix (ECM) components were observed, and the CSDP culture time was prolonged. The expression of alkaline phosphatase (ALP), dentine sialoprotein (DSPP), bone sialoprotein (BSP) and runt-related gene 2 (RUNX2) mRNA was higher in CSDPs than in cell sheets (CSs), indicating that CSDPs have greater odonto/osteogenic potential. To further investigate this hypothesis, CSDPs and CSs were inserted into human treated dentine matrix fragments (hTDMFs) and transplanted into the subcutaneous space in the backs of immunodeficient mice, where they were cultured in vivo for 6 weeks. The root space with CSDPs was filled entirely with a dental pulp-like tissue with well-established vascularity, and a continuous layer of dentine-like tissue was deposited onto the existing dentine. A layer of odontoblast-like cells was found to express DSPP, ALP and BSP, and human mitochondria lined the surface of the newly formed dentine-like tissue. These results clearly indicate that SCAP-CSDPs with a mount of endogenous ECM have a strong capacity to form a heterotopic dental pulp/dentine complex in empty root canals; this method can be used in the fabrication of bioengineered dental roots and also provides an alternative treatment approach for pulp disease. Copyright © 2013 John Wiley & Sons, Ltd. PMID:23365018

  8. Oxalate desensitising treatment of dentinal surface.

    PubMed

    Mongiorgi, R; Prati, C; Toschi, E; Riva di Sanseverino, L

    1991-04-01

    It is well known that a typical painful feeling is caused by impact of different agents and by thermodynamic conditions upon the dentine layer of the tooth. Therefore the action by artificial solutions should be tested to study how the induced modifications might inhibit the pain. The aim of the present study is to evaluate by scanning electron microscopy (SEM) the morphology of dentine surface after different chemical treatments. Oxalate solutions are able to produce a layer of large crystals, while acid solutions remove the smear layer and open the dentinal tubules. PMID:1910743

  9. Hypersensitive dentinal pain attenuation with potassium nitrate.

    PubMed

    Touyz, L Z; Stern, J

    1999-01-01

    Dentinal hypersensitivity occurs when gingival recession exposes dentin at the cervical margins of teeth. Twenty-four periodontal patients, with postoperative hypersensitive dentin were treated by burnishing saturated potassium nitrate (KNO3) to relieve pain. Using a visual analogue scale with participants acting as their own control, a subjective assessment of pain was measured and compared before and after KNO3 application. Thirty-six regions involving 98 teeth were assessed. A significant reduction of sensitivity and pain was achieved by using a saturated KNO3 solution (p < .0001 Student-t). PMID:10321150

  10. Wavelength and average power density dependency of the recrystallization of tooth dentin using a MIR-FEL

    NASA Astrophysics Data System (ADS)

    Heya, Manabu; Awazu, Kunio

    2002-04-01

    Recrystallization of tooth dentin by the application of mid- infrared (MIR) pulsed-laser irradiation is one candidate for a novel, non-invasive treatment for the prevention of tooth decay. Recrystallized dentin functions in a similar way to dental enamel. To recrystallize the dentin effectively and non-invasively it is essential to estimate quantitatively and qualitatively the laser parameters, such as the wavelength and the average power density, required for recrystallization. The laser-tissue interaction is initiated effectively by selective excitation of phosphate acid ions (PO4) in the dentin. Using a tunable, MIR Free Electron Laser (FEL) in the wavelength region of 8.8- 10.6micrometers , corresponding to intense absorption bands due to PO4 vibration modes, we have investigated macroscopically extent of surface modification of dentin, and we have obtained experimental results related to the ablation depth, the MIR absorption spectrum, and the elemental chemical composition. From these results, it was found that (1) the laser parameters at which efficient surface modification, without enhanced ablation effects, occurred were estimated to be approximately in the wavelength and average power density regions of ~9.4- 10.3micrometers and ~10-20 W/cm2, and that (2) in this region PO4 vibration modes with lower binding energy were preferentially excluded from the dentin.

  11. An in vitro investigation of penetration depth of dentine bonding agents into carious dentine.

    PubMed

    Hahn, P; Hellwig, E

    2004-11-01

    The aim of the present in vitro study was to determine the penetration depth of dentine bonding agents into carious dentine as a possible strategy in caries treatment of deep lesions. Forty-eight extracted carious teeth were used for the experiments and divided in four groups. In a split-tooth design, one half of each tooth was treated without caries excavation, and the second half after caries excavation. In group 1 the teeth were treated with Prime & Bond 2.0 without phosphoric acid etching, and in group 2 with phosphoric acid etching. In group 3, the teeth were treated with All-Bond 2 without phosphoric acid etching, and in group 4 with phosphoric acid etching. Bonding agents were marked with an orange dye prior to application. The composition of the bonding agents had no significant influence on penetration depths. The mean thickness of the outer, necrotic caries zone in unexcavated specimens was 117 microm (+/-126). Bonding agents penetrated significantly deeper into unexcavated carious dentine (mean 124 +/- 76 microm) compared with excavated dentine (11 +/- 14 microm) and sound dentine (3 +/- 4 microm). Acid etching significantly reduced the thickness of the outer caries zone, and the penetration depth of the bonding agents into unexcavated carious specimens by approximately 50%, and increased it into sound dentine. The results indicate that dentine bonding agents could completely penetrate the unexcavated outer carious dentine in 90% of specimens. Further studies are required to determine whether further caries activity is arrested after treatment with dentine bonding procedures. PMID:15525382

  12. Dentinal composition and Knoop hardness measurements of cavity floor following carious dentin removal with Carisolv.

    PubMed

    Hossain, Mozammal; Nakamura, Yukio; Tamaki, Yukimichi; Yamada, Yoshishige; Jayawardena, Jayanetti Asiri; Matsumoto, Koukichi

    2003-01-01

    This study evaluated the dentinal composition and Knoop hardness measurements of the cavity floor following the removal of carious dentin by the Carisolv chemo-mechanical caries removal system, in vitro. The carious dentin of 25 extracted human teeth was removed by using Carisolv for one minute with instruments and excavation that was performed until the gel was clear. Caries removal with a sharp explorer was verified according to the color and hardness of the lesion, then, by means of DIAGNOdent. Atomic analysis of treated cavities was performed by energy dispersive x-ray spectroscopy (SEM-EDX) and the Knoop hardness number (KHN) of the cavity floor was determined. Surface characteristics were observed by the scanning electron microscope (SEM). Adjacent sound dentin was used as a control reference. No significant differences were found between the quantities of calcium content (Ca weight %), phosphorus content (P weight %) and the Ca/P weight ratio of Carisolv cavities with that of the adjacent, sound dentin (p<0.01). KHN of the Carisolv cavity floor was almost similar to that of the adjacent sound dentin. SEM analysis revealed an extremely rough or irregular surface, and there remained a minimal debris-like smear layer; most of the dentinal tubules were opened. The results indicated that Carisolv does not produce any adverse side effects on dentinal compositions of the treated cavities. The possibility of remaining residual softened dentin was also minimal in this study. PMID:12877418

  13. Near tubule and intertubular bovine dentin mapped at the 250 nm level

    PubMed Central

    Stock, S. R.; Veis, A.; Telser, A.; Cai, Z.

    2011-01-01

    In this study, simultaneous diffraction and fluorescence mapping with a (250 nm)2, 10.1 keV synchrotron x-ray beam investigated the spatial distribution of carbonated apatite (cAp) mineral and elemental Ca (and other cations including Zn) around dentin tubules. In 1 μm thick sections of near-pulp root dentin, where peritubular dentin (PTD) is newly forming, high concentrations of Zn, relative to those in intertubular dentin (ITD), were observed adjacent to and surrounding the tubule lumens. Some but not all tubules exhibited hypercalcified collars (high Ca signal relative to the surrounding ITD), and, when present, the zone of high Ca did not extend around the tubule. Diffraction rings from cAp 00.2 and 11.2+21.1+30.0 reflections were observed, and cAp was the only crystal phase detected. Profiles of Ca, Zn and cAp diffracted intensities showed the same transitions from solid to tubule lumen, indicating the same cAp content and organization in ITD far from the tubules and adjacent to them. Further, the matching Ca and diffraction profiles demonstrated that all of the Ca is in cAp or that any noncrystalline Ca was uniformly distributed throughout the dentin. Variation of 00.2 and 11.2+21.1+30.0 diffracted intensity was consistent with the expected biaxial crystallographic texture. Extension of x-ray mapping from near 1 μm resolution to the 250 nm level, performed here for dentin and its tubules, will provide new understanding of other mineralized tissues. PMID:21821132

  14. Efficacy of stannous, fluoride and their their combination in dentin erosion prevention in vitro.

    PubMed

    Algarni, Amnah Abdullah; Lippert, Frank; Hara, Anderson Takeo

    2015-01-01

    The aim of this study was to compare the protective effects of solutions containing stannous (Sn), fluoride (F) and their combination in the prevention of dentin erosion. Forty bovine root dentin specimens (4'4'2 mm(3)) were prepared and randomly assigned to 4 groups (n = 10): SnCl2 (800 ppm/6.7 mM Sn), NaF (250 ppm/13 mM F), NaF/SnCl2 (800 ppm/6.7 mM Sn; 250 ppm/13 mM F), and deionized water (DIW) as a negative control. An acquired pellicle was formed on dentin samples by incubation in clarified, pooled, stimulated human saliva for 24 hours. The specimens were subjected to 5 daily cycles, each consisting of 5 of min demineralization (0.3%/15.6 mM citric acid, pH 2.6, 6'/day) and 60 min of re-mineralization in clarified human saliva. Thirty minutes after the 1st, 3rd and 5th demineralization episodes of each day, the specimens were treated with one of the test solutions for 2 min. Surface loss was measured via optical profilometry. Mixed-model ANOVA followed by Tukey's test were used for the statistical analysis. Sn, F, and their combination significantly reduced the dentin surface loss by 23%, 36%, and 60% compared with DIW, respectively. All groups were significantly different (p < 0.05). The combination of Sn and F significantly reduced the amount of dentin surface loss compared with all other groups. The F group also significantly reduced surface loss compared with Sn and DIW, followed by the Sn group, which showed significantly greater protection compared with the DIW control. The daily use of a combined fluoride and stannous solution is promising for preventing dentin erosion. PMID:26106907

  15. Degradation in the Dentin-Composite Interface Subjected to Multi-Species Biofilm Challenges

    PubMed Central

    Li, Yuping; Carrera, Carola; Chen, Ruoqiong; Li, Jianying; Patricia, Lenton; Rudney, Joel. D.; Jones, Robert S.; Aparicio, Conrado; Fok, Alex

    2013-01-01

    Oral biofilms can degrade the components in dental resin-based composite restorations, thus compromising marginal integrity and leading to secondary caries. In this study, we investigated the mechanical integrity of the dentin-composite interface challenged with multi-species oral biofilms. While most studies used single-species biofilms, we used a more realistic, diverse biofilm model produced directly from plaques collected from donors with a history of early childhood caries. Dentin–composite disks were made using bovine incisor roots filled with Z100™ or Filtek™ LS (3M ESPE). The disks were incubated for 72hr in paired CDC biofilm reactors, using a previously published protocol. One reactor was pulsed with sucrose, and the other was not. A sterile saliva-only control group was run with sucrose pulsing. The disks were fractured under diametral compression to evaluate their interfacial bond strength. Surface deformation of the disks was mapped using digital image correlation (DIC) to ascertain fracture origin. Fracture surfaces were examined using SEM/EDS to assess demineralization and interfacial degradation. Dentin demineralization was greater under sucrose-pulsed biofilms, as the pH dropped below 5.5 during pulsing, with LS and Z100 specimens suffering similar degrees of surface mineral loss. Biofilm growth with sucrose pulsing also caused preferential degradation of the composite-dentin interface, depending on the composite/adhesive system used. Specifically, Z100 specimens showed greater bond strength reduction and more frequent cohesive failure in the adhesive layer. This was attributed to the inferior dentin coverage by Z100 adhesive which possibly led to a higher level of chemical and enzymatic degradation. The results suggested that factors other than dentin demineralization were also responsible for interfacial degradation. We have thus developed a clinically relevant in vitro biofilm model which would allow us to effectively assess the

  16. Dentin bond strength of light-cured glass-ionomer cements.

    PubMed

    Hinoura, K; Miyazaki, M; Onose, H

    1991-12-01

    The purpose of this study was to investigate the influence of surface treatments and irradiation conditions on the bond strength of light-cured glass-ionomer cements to dentin. The light-cured glass-ionomer cements used in this study were Vitrabond, XR Ionomer, and Fuji Lining LC. Three experiments were designed to study the influence of the following factors on bond strength to dentin: (1) effect of the surface treatment of the dentin, (2) effect of the irradiation time, (3) effect of an increase in the interval between mixing of the cement and irradiation. Samples were stored in water for 24 hours, after which shear bond testing was performed at a cross-head speed of 1 mm/min. For Vitrabond, the Scotchprep and Gluma 2 treatments gave the greatest shear bond strengths. For XR Ionomer and Fuji Lining LC, the Scotchprep treatment gave the greatest shear bond strengths. The bond strengths for all cements increased with prolonged irradiation time. Bond strengths decreased with a longer elapsed time between mixing and light-curing. This means that light-curing should be done soon after the cement is placed. The failure mode was found to be cohesive in the ionomer. PMID:1774385

  17. Dentine chips produced by nickel-titanium rotary instruments.

    PubMed

    Guppy, D R; Curtis, R V; Ford, T R

    2000-12-01

    This study aimed to compare the cross-sectional shape of two nickel-titanium rotary instruments, namely ProFile and Quantec files, both ISO 25, 0.06 taper, and sought to relate this to the chips produced by cutting dentine. A limited comparison was made with stainless steel engine reamers. First, five files of each type were sectioned transversely at 12 mm, 8 mm and 4 mm from the tip and examined by scanning electron microscopy. The cutting angles were assessed by a direct measurement technique which allowed for the inclination of a cutting edge to the root canal. Second, eight samples of cutting debris were collected from instrumentation by each type of nickel-titanium file and four samples from the engine reamers. The major and minor axis, area and roundness of the dentine chips in each sample were measured using computerized particle analysis. The results demonstrated that all files had a negative cutting angle which varied at the different levels (ProFiles range 69.4 degrees to 58.4 degrees and Quantec range 74.8 degrees to 56.8 degrees). The consistency within files of the same type was good as demonstrated by low standard deviations, except for Quantec files at the 4 mm level where higher standard deviations of 4.1 degrees and 5.5 degrees for the two blades were found. The chip analysis showed significant differences between chips produced by ProFile and Quantec files (P < 0.05). The latter were larger and rounder. The chips from the ProFile and the engine reamer chips were similar in dimension (P > 0.05). No simple relationship existed between file geometry and the dentine chips produced during instrumentation. PMID:11202891

  18. Evaluation of dentin permeability after light activated internal dental bleaching.

    PubMed

    Carrasco, Laise Daniela; Zanello Guerisoli, Danilo M; Pécora, Jesus Djalma; Fröner, Izabel Cristina

    2007-02-01

    The aim of this in vitro study was to assess quantitatively the dentin permeability of human teeth after intracoronal bleaching therapy with 35% hydrogen peroxide activated by LEDs, halogen lamp or using the walking bleach technique. Forty human maxillary central incisors had standard access cavities performed and the cervical thirds of the canals were prepared with Gates-Glidden drills up to a size 130. Roots were resected between the coronal and middle thirds and the apical portions were discarded. A glass ionomer, 2 mm thick cervical plug was placed inside the canal, at the cement-enamel junction level. Group I received 35% hydrogen peroxide gel activated by LEDs. Group II was submitted to 35% hydrogen peroxide gel activated by halogen lamp. Group III received 35% hydrogen peroxide gel and the walking bleach technique was followed. Group IV (control) received a dry cotton pellet inside the pulp chamber with temporary restoration. Dentinal permeability was quantified by copper ion penetration. Linear measurements were obtained by analysis of digital images under x 5 magnification. Mean values and SD for the experimental groups were: I, 7.1% (+/-3.2%); II, 8.4% (+/-3.0%); III, 9.1% (+/-3.0%); IV, 1.3% (+/-2.8%). One-way ANOVA was used to analyze the results. Results showed an increase of permeability values for groups I, II and III when compared to group IV (control); however, no statistical differences were found between the three tested bleaching techniques. It can be concluded that 35% hydrogen peroxide activated by LED, halogen lamp or used following the walking bleach technique produced similar increase in dentinal permeability. PMID:17227378

  19. Pulp-dentin Regeneration: Current State and Future Prospects.

    PubMed

    Cao, Y; Song, M; Kim, E; Shon, W; Chugal, N; Bogen, G; Lin, L; Kim, R H; Park, N-H; Kang, M K

    2015-11-01

    The goal of regenerative endodontics is to reinstate normal pulp function in necrotic and infected teeth that would result in reestablishment of protective functions, including innate pulp immunity, pulp repair through mineralization, and pulp sensibility. In the unique microenvironment of the dental pulp, the triad of tissue engineering would require infection control, biomaterials, and stem cells. Although revascularization is successful in resolving apical periodontitis, multiple studies suggest that it alone does not support pulp-dentin regeneration. More recently, cell-based approaches in endodontic regeneration based on pulpal mesenchymal stem cells (MSCs) have demonstrated promising results in terms of pulp-dentin regeneration in vivo through autologous transplantation. Although pulpal regeneration requires the cell-based approach, several challenges in clinical translation must be overcome-including aging-associated phenotypic changes in pulpal MSCs, availability of tissue sources, and safety and regulation involved with expansion of MSCs in laboratories. Allotransplantation of MSCs may alleviate some of these obstacles, although the long-term stability of MSCs and efficacy in pulp-dentin regeneration demand further investigation. For an alternative source of MSCs, our laboratory developed induced MSCs (iMSCs) from primary human keratinocytes through epithelial-mesenchymal transition by modulating the epithelial plasticity genes. Initially, we showed that overexpression of ΔNp63α, a major isoform of the p63 gene, led to epithelial-mesenchymal transition and acquisition of stem characteristics. More recently, iMSCs were generated by transient knockdown of all p63 isoforms through siRNA, further simplifying the protocol and resolving the potential safety issues of viral vectors. These cells may be useful for patients who lack tissue sources for endogenous MSCs. Further research will elucidate the level of potency of these iMSCs and assess their

  20. Isolated dentinogenesis imperfecta and dentin dysplasia: revision of the classification.

    PubMed

    de La Dure-Molla, Muriel; Philippe Fournier, Benjamin; Berdal, Ariane

    2015-04-01

    Dentinogenesis imperfecta is an autosomal dominant disease characterized by severe hypomineralization of dentin and altered dentin structure. Dentin extra cellular matrix is composed of 90% of collagen type I and 10% of non-collagenous proteins among which dentin sialoprotein (DSP), dentin glycoprotein (DGP) and dentin phosphoprotein (DPP) are crucial in dentinogenesis. These proteins are encoded by a single gene: dentin sialophosphoprotein (DSPP) and undergo several post-translational modifications such as glycosylation and phosphorylation to contribute and to control mineralization. Human mutations of this DSPP gene are responsible for three isolated dentinal diseases classified by Shield in 1973: type II and III dentinogenesis imperfecta and type II dentin dysplasia. Shield classification was based on clinical phenotypes observed in patient. Genetics results show now that these three diseases are a severity variation of the same pathology. So this review aims to revise and to propose a new classification of the isolated forms of DI to simplify diagnosis for practitioners. PMID:25118030

  1. Identification of dentin phosphophoryn localization by histochemical stainings.

    PubMed

    Takagi, Y; Fujisawa, R; Sasaki, S

    1986-01-01

    Phosphophoryn, the most abundant of the dentin non-collagenous proteins, has been considered to be related in function to the mineralization process. In the present study, identification of dentin phosphophoryn localization was attempted using newly developed, precautionary histological methods by which phosphophoryn was retained in the sections during the specimen preparation and stained selectively in situ. Phosphophoryn was found to be present widely in all of the calcified dentin except the mantle dentin, the external, first-formed portion of dentin, but was not found in the predentin, the inner, uncalcified layer of dentin. These results indicate that phosphophoryn is apparently related to the mineral phase of calcified dentin and that the mineralization process of mantle dentin, which is formed before the odontoblasts are fully differentiated, may be different from that of circumpulpal dentin. PMID:2421974

  2. Micro-tensile bond strength of two adhesives to Erbium:YAG-lased vs. bur-cut enamel and dentin.

    PubMed

    De Munck, Jan; Van Meerbeek, Bart; Yudhira, Rafaël; Lambrechts, Paul; Vanherle, Guido

    2002-08-01

    The purpose of the study was to assess the hypotheses that laser irradiation is equally effective for bonding as traditional acid-etch procedures, and that tooth substrate prepared either by Erbium:YAG laser or diamond bur is equally receptive to adhesive procedures. Buccal/oral enamel and mid-coronal dentin were laser-irradiated using an Erbium:YAG laser. A total-etch adhesive (OptiBond FL) applied with and without prior acid-etching and a self-etch adhesive (Clearfil SE Bond) were employed to bond the composite. The micro-tensile bond strength (microTBS) was determined after 24 h of storage in water. Failure patterns were analysed using a stereo-microscope, and samples were processed for Field-emission Scanning Electron Microscopy (Fe-SEM) evaluation. Unbonded, lased enamel and dentin surfaces were evaluated using Fe-SEM as well. The total-etch adhesive bonded significantly less effectively to lased than to bur-cut enamel/dentin. Laser 'conditioning' was clearly less effective than acid-etching. Moreover, acid etching lased enamel and dentin significantly improved the microTBS of OptiBond FL. The self-etch adhesive performed equally to lased as to bur-cut enamel, but significantly less effectively to lased than to bur-cut dentin. It is concluded that cavities prepared by laser appear less receptive to adhesive procedures than conventional bur-cut cavities. PMID:12206595

  3. Biodentine-a novel dentinal substitute for single visit apexification

    PubMed Central

    Hasan, Mohammad Faiz

    2014-01-01

    Use of an apical plug in management of cases with open apices has gained popularity in recent years. Biodentine, a new calcium silicate-based material has recently been introduced as a dentine substitute, whenever original dentine is damaged. This case report describes single visit apexification in a maxillary central incisor with necrotic pulp and open apex using Biodentine as an apical barrier, and a synthetic collagen material as an internal matrix. Following canal cleaning and shaping, calcium hydroxide was placed as an intracanal medicament for 1 mon. This was followed by placement of small piece of absorbable collagen membrane beyond the root apex to serve as matrix. An apical plug of Biodentine of 5 mm thickness was placed against the matrix using pre-fitted hand pluggers. The remainder of canal was back-filled with thermoplasticized gutta-percha and access cavity was restored with composite resin followed by all-ceramic crown. One year follow-up revealed restored aesthetics and function, absence of clinical signs and symptoms, resolution of periapical rarefaction, and a thin layer of calcific tissue formed apical to the Biodentine barrier. The positive clinical outcome in this case is encouraging for the use of Biodentine as an apical plug in single visit apexification procedures. PMID:24790925

  4. Power toothbrushes, gender, and dentin hypersensitivity.

    PubMed

    Hefti, A F; Stone, C

    2000-06-01

    Power toothbrushes require less force for plaque removal than manual brushes. In addition, in vitro studies have indicated that brushing with low force could occlude patent dentin tubules by formation of a smear layer. Hence, lessening the force necessary to remove plaque may reduce dentin hypersensitivity. However, it was recently suggested that the use of an oscillating/rotating power toothbrush could decrease tooth sensitivity as compared to a sonic power toothbrush. Therefore, the objective of the present research was to compare the effect on dentin hypersensitivity of two different types of power brushes, the Optiva Sonicare and the Braun Oral B Ultra Plaque Remover. The null hypothesis was tested in an 8-week, randomized, parallel group, examiner-blind clinical trial. Fifty-nine subjects with a history of dentin hypersensitivity participated. Dentin hypersensitivity-associated pain was elicited using tactile and evaporative stimuli and assessed using a visual analog scale (VAS) instrument. Clinical examinations were carried out at screening and baseline and repeated after 8 weeks of twice daily use of the power brushes. Data analysis was performed on VAS scores obtained at the final visit following adjustment for group differences at baseline. A 35% to 40% reduction in pain as compared to baseline was observed in both treatment groups. Treatment-related differences were not statistically significant. A gender-related effect on dentin hypersensitivity was observed using the tactile stimulus and may merit further investigation. PMID:11218507

  5. Nanomechanical properties of dentin treated with a CO II laser for potential caries inhibition

    NASA Astrophysics Data System (ADS)

    Habelitz, Stefan; Fried, Daniel; Le, Charles Q.; Featherstone, John D.

    2008-02-01

    The effect of pulsed CO II-laser treatments on the microstructure and nanomechanical properties was studied using atomic force microscopy and nanoindentation. The microstructure and roughness of dentin specimens treated by a 9.3 μm CO II laser at fluences of 0.5; 0.75; 1.0; and 1.5 J/cm2 were evaluated and the elastic modulus and hardness before and after a nine days demin/remin application for laser treatments at 0.75 and 1.5 J/cm2 were determined. The hypothesis that CO II-laser-treatments reduce or inhibit the demineralization process was tested. Surface cracks were observed at fluences of 0.75 J/cm2 and higher. Surface roughness increased strongly after laser irradiation and was about 10 times higher at maximum fluence. Mechanical properties profiles from the laser treated surface to sound dentin showed increased modulus and hardness values at dentin surfaces treated, indicating removal of organic phases and reinforcement of the tissue by increased mineral content. Mechanical properties decreased after demin/remin application in all groups and the hardened surface layer disappeared for samples treated at 0.75 J/cm2. While increased properties were still observed in the laser affected surface zone for treatments at 1.5 J/cm2, demineralization was severe underneath these layers as indicated by a sharp drop in properties. The depth of demineralization was slightly decreased in the laser-treated group compared to the untreated controls. We conclude that CO II-laser treatments produce dentin surfaces with increased nanomechanical properties. These surface layers do not, however, provide protection against demineralization due to surface cracking and possible delamination. Moreover, the surface cracks induced by the laser-irradiation raise concerns about a clinical potential for caries inhibition in dentin.

  6. The Role of Host-derived Dentinal Matrix Metalloproteinases in Reducing Dentin Bonding of Resin Adhesives

    PubMed Central

    Zhang, Shan-chuan; Kern, Matthias

    2009-01-01

    Dentin matrix metalloproteinases (MMPs) are a family of host-derived proteolytic enzymes trapped within mineralized dentin matrix, which have the ability to hydrolyze the organic matrix of demineralized dentin. After bonding with resins to dentin there are usually some exposed collagen fibrils at the bottom of the hybrid layer owing to imperfect resin impregnation of the demineralized dentin matrix. Exposed collagen fibrils might be affected by MMPs inducing hydrolytic degradation, which might result in reduced bond strength. Most MMPs are synthesized and released from odontoblasts in the form of proenzymes, requiring activation to degrade extracellular matrix components. Unfortunately, they can be activated by modern self-etch and etch-and-rinse adhesives. The aim of this review is to summarize the current knowledge of the role of dentinal host-derived MMPs in dentin matrix degradation. We also discuss various available MMP inhibitors, especially chlorhexidine, and suggest that they could provide a potential pathway for inhibiting collagen degradation in bonding interfaces thereby increasing dentin bonding durability. PMID:20690420

  7. CBX7 deficiency plays a positive role in dentin and alveolar bone development.

    PubMed

    Zhou, Zhixuan; Yin, Ying; Jiang, Fei; Niu, Yuming; Wan, Shujian; Chen, Ning; Shen, Ming

    2016-08-01

    To clarify the role of CBX7 deficiency in dentin and alveolar bone development, the dental and mandibular phenotypes of homozygous CBX7-knockout (CBX7(-/-)) mice were compared with their wild-type (WT) counterparts at 3 weeks age. In contrast to WT littermates, dental volume and dentin sialoprotein-positive area were significantly increased, whereas the area ratio of predentin to dentin was decreased markedly in CBX7(-/-) mice. Mineral density, cortical thickness, alveolar bone volume, type I collagen and osterix-immunopositive area, osteoblast number and activity, protein expression and mRNA level of Runt-related transcription factor 2 (Runx2), alkaline phosphatase, osteocalcin, osteopontin and bone morphogenetic protein 2 (BMP2) were all remarkably increased, while osteoclast number and activity, and mRNA expression ratio of NF-κB ligand (RANKL) to osteoprotegerin (opg) were all decreased significantly in the alveolar bone of CBX7(-/-) mice compared with their WT counterparts. Moreover, proliferating cell nuclear antigen (PCNA)-positive cells were found more in Hertwig' s epithelial root sheath of CBX7(-/-) mice, and their protein level of cyclin E1, cyclin-dependent kinase 2 (CDK2) were correspondingly increased in contrast to WT mice. Taken together, these results of this study suggest that CBX7 deficiency plays a positive role in dentin and alveolar bone formation. PMID:27271093

  8. Pulp responses to precise thermal stimuli in dentin-sensitive teeth.

    PubMed

    Leffingwell, Clifford S; Meinberg, Trudy A; Wagner, Joshua G; Gound, Tom G; Marx, David B; Reinhardt, Richard A

    2004-06-01

    The purpose of this study was to determine whether pulpal responses to cold temperatures applied to enamel, using a method that precisely controls the intensity of the cold stimulus or measures the response time, could distinguish dentin-sensitive teeth from nonsensitive teeth. Eighteen human subjects were stimulated with cold temperatures decreasing in 5 degree C intervals (and with tetrafluoroethane) on exposed root and enamel of a dentin-sensitive tooth and enamel of a contralateral nonsensitive tooth. Pain threshold, intensity of pain, time to pain onset, and duration of pain at baseline, 4 h, 8 h, and 1 week were measured. Responses to enamel stimulation of sensitive teeth compared with the nonsensitive teeth usually were highly correlated and not significantly different. The exception was a longer duration of pain in the dentin-sensitive teeth (4.62 +/- 0.47 s) compared with nonsensitive teeth (2.92 +/- 0.49 s; p = 0.016) after enamel stimulation with tetrafluoroethane. Longitudinal studies are necessary to determine whether these slight increases in pain duration indicate an increased probability of pulpal degeneration or need for dentin protection. PMID:15167462

  9. Effects of human vascular endothelial growth factor on reparative dentin formation

    PubMed Central

    ZHANG, JUAN; LIU, XIA; YU, WEIXIAN; ZHANG, YINGLI; SHI, CE; NI, SHILEI; LIU, QILIN; LI, XIANGWEI; SUN, YINGJIAN; ZHENG, CHANGYU; SUN, HONGCHEN

    2016-01-01

    It is a challenge for dentists to save dental pulp in patients with pulp disease without resorting to root canal therapy. Formation of tertiary dentin to maintain pulp vitality is a key odontoblast response to dental pulp injury. Vascular endothelial growth factor (VEGF) is the most potent angiogenic and vasculogenic factor involved in tertiary dentin formation. It was hypothesized that VEGF may be used to treat pulp diseases such as pulpitis. To explore this hypothesis, the first step was to assess whether VEGF affects dental pulp cells to promote reparative dentin formation. In the current study, an AdCMV-hVEGF vector was constructed to deliver hVEGF into dental pulp cells of exfoliated deciduous teeth (hDPCs) in vitro and dental pulp cells in a rat model in vivo. The collected data clearly demonstrated that hVEGF increased alkaline phosphatase and mineralization by enzymatic activity. RT-qPCR data demonstrated that hVEGF significantly increased the expression levels of genes commonly involved in osteogenesis/odontogenesis. Data from the in vivo assays indicated that hVEGF enhanced pulp cell proliferation and neovascularization, and markedly increased formation of reparative dentin in dental pulp. The in vitro and in vivo data suggest that hVEGF may have potential clinical applications, thus may aid in the development of novel treatment strategies for dental pulpitis. PMID:26647730

  10. Effects of human vascular endothelial growth factor on reparative dentin formation.

    PubMed

    Zhang, Juan; Liu, Xia; Yu, Weixian; Zhang, Yingli; Shi, Ce; Ni, Shilei; Liu, Qilin; Li, Xiangwei; Sun, Yingjian; Zheng, Changyu; Sun, Hongchen

    2016-01-01

    It is a challenge for dentists to save dental pulp in patients with pulp disease without resorting to root canal therapy. Formation of tertiary dentin to maintain pulp vitality is a key odontoblast response to dental pulp injury. Vascular endothelial growth factor (VEGF) is the most potent angiogenic and vasculogenic factor involved in tertiary dentin formation. It was hypothesized that VEGF may be used to treat pulp diseases such as pulpitis. To explore this hypothesis, the first step was to assess whether VEGF affects dental pulp cells to promote reparative dentin formation. In the current study, an AdCMV‑hVEGF vector was constructed to deliver hVEGF into dental pulp cells of exfoliated deciduous teeth (hDPCs) in vitro and dental pulp cells in a rat model in vivo. The collected data clearly demonstrated that hVEGF increased alkaline phosphatase and mineralization by enzymatic activity. RT‑qPCR data demonstrated that hVEGF significantly increased the expression levels of genes commonly involved in osteogenesis/odontogenesis. Data from the in vivo assays indicated that hVEGF enhanced pulp cell proliferation and neovascularization, and markedly increased formation of reparative dentin in dental pulp. The in vitro and in vivo data suggest that hVEGF may have potential clinical applications, thus may aid in the development of novel treatment strategies for dental pulpitis. PMID:26647730

  11. Root conditioning in periodontology — Revisited

    PubMed Central

    Nanda, Tarun; Jain, Sanjeev; Kaur, Harjit; Kapoor, Daljit; Nanda, Sonia; Jain, Rohit

    2014-01-01

    Objective: Root surfaces of periodontitis-affected teeth are hypermineralized and contaminated with cytotoxic and other biologically active substances. To achieve complete decontamination of the tooth surfaces, various methods including root conditioning following scaling and root planning are present. The main objective of this article is to throw light on the different root conditioning agents used and the goals accomplished by root conditioning in the field of periodontology. Materials and Methods: 20 human maxillary anterior teeth indicated for extraction due to chronic periodontitis were collected and root planned. The teeth were sectioned and specimens were divided into two groups — Group I and II. Group I dentin specimens were treated with EDTA and group II specimens were treated with tetracycline HCl solution at concentration of 10% by active burnishing technique for 3 minutes. The root surface samples were then examined by scanning electron microscope (SEM). Results: The results of the study showed that EDTA and tetracycline HCl were equally effective in removing the smear layer. It was observed that the total and patent dentinal tubules were more in number in teeth treated with tetracycline as compared to EDTA group. However, EDTA was found to be much more effective as root conditioning agent because it enlarged the diameter of dentinal tubules more than that of tetracycline HCl. Conclusion: Results of in-vitro study showed that both the agents are good root conditioning agents if applied in addition to periodontal therapy. However, further studies are required to establish the in-vivo importance of EDTA and tetracycline HCL as root conditioners. PMID:25097414

  12. Adhesion to chondroitinase ABC treated dentin

    PubMed Central

    Mazzoni, Annalisa; Pashley, David H.; Ruggeri, Alessandra; Vita, Francesca; Falconi, Mirella; Di Lenarda, Roberto; Breschi, Lorenzo

    2013-01-01

    Dentin bonding relies on complete resin impregnation throughout the demineralised hydrophilic collagen mesh. Chondroitin sulphate-glycosaminoglycans are claimed to regulate the three-dimensional arrangement of the dentin organic matrix and its hydrophilicity. The aim of this study was to investigate bond strength of two etch-and-rinse adhesives to chondroitinase ABC treated dentin. Human extracted molars were treated with chondroitinase ABC and a double labelling immunohistochemical technique was applied to reveal type I collagen and chondroitin 4/6 sulphate distribution under field emission in-lens scanning electron microscope. The immunohistochemical technique confirmed the effective removal of chondroitin 4/6 sulphate after the enzymatic treatment. Dentin surfaces exposed to chondroitinase ABC and untreated specimens prepared on untreated acid-etched dentin were bonded with Adper Scotchbond Multi-Purpose or Prime & Bond NT. Bonded specimens were submitted to microtensile testing and nanoleakage interfacial analysis under transmission electron microscope. Increased mean values of microtensile bond strength and reduced nanoleakage expression were found for both adhesives after chondroitinase ABC treatment of the dentin surface. Adper Scotchbond Multi-Purpose increased its bond strength about 28%, while bonding made with Prime & Bond NT almost doubled (92% increase) compared to untreated specimens. This study supports the hypothesis that adhesion can be enhanced by removal of chondroitin 4/6 sulphate and dermatan sulphate, probably due to a reduced amount of water content and enlarged interfibrillar spaces. Further studies should validate this hypothesis investigating the stability of chondroitin 4/6 and dermatan sulphate-depleted dentin bonded interface over time. PMID:18161809

  13. Clinical status of ten dentin adhesive systems.

    PubMed

    Van Meerbeek, B; Peumans, M; Verschueren, M; Gladys, S; Braem, M; Lambrechts, P; Vanherle, G

    1994-11-01

    Laboratory testing of dentin adhesive systems still requires corroboration by long-term clinical trials for their ultimate clinical effectiveness to be validated. The objective of this clinical investigation was to evaluate, retrospectively, the clinical effectiveness of earlier-investigated dentin adhesive systems (Scotchbond, Gluma, Clearfil New Bond, Scotchbond 2, Tenure, and Tripton), and to compare their clinical results with those obtained with four modern total-etch adhesive systems (Bayer exp. 1 and 2, Clearfil Liner Bond System, and Scotchbond Multi-Purpose). In total, 1177 Class V cervical lesions in the teeth of 346 patients were restored following two cavity designs: In Group A, enamel was neither beveled nor intentionally etched, as per ADA guidelines; in Group B, adjacent enamel was beveled and conditioned. Clinical retention rates definitely indicated the improved clinical efficacy of the newest dentin adhesives over the earlier systems. With regard to adhesion strategy, adhesive systems that removed the smear layer and concurrently demineralized the dentin surface layer performed clinically better than systems that modified the disorderly layer of smear debris without complete removal. Hybridization by resin interdiffusion into the exposed dentinal collagen layer, combined with attachment of resin tags into the opened dentin tubules, appeared to be essential for reliable dentin bonding but might be insufficient by itself. The additional formation of an elastic bonding area as a polymerization shrinkage absorber and the use of a microfine restorative composite apparently guaranteed an efficient clinical result. The perfect one-year retention recorded for Clearfil Liner Bond System and Scotchbond Multi-Purpose must be confirmed at later recalls. PMID:7983255

  14. Shear test of composite bonded to dentin: Er:YAG laser versus dental handpiece preparations

    NASA Astrophysics Data System (ADS)

    Visuri, Steven R.; Gilbert, Jeremy L.; Walsh, Joseph T., Jr.; Wigdor, Harvey A.

    1995-05-01

    The erbium:YAG laser coupled with a cooling stream of water appears to be an effective means of removing dental hard tissues. However, before the procedure is deemed clinically viable, there are several important issues of safety and efficacy that need to be explored. In this study we investigated the surface that remains following laser ablation of dentin and compared the results to the use of a dental handpiece. Specifically, we studied the effect the laser radiation had on the bonding of composite to dentin. The crowns of extracted human molars were removed revealing the underlying dentin. An additional thickness of material was removed with either a dental handpiece or an Er:YAG laser by raster scanning the samples under a fixed handpiece or laser. Comparable surface roughnesses were achieved. A cylinder of composite was bonded onto the prepared surfaces following the manufacturer's directions. The dentin-composite bond was then shear stressed to failure on a universal testing apparatus and the maximum load recorded. Preliminary results indicated that laser irradiated samples had improved bond strengths. SEM photographs of the surfaces were also taken to compare the two methods of tooth preparation.

  15. Effects of Tetracycline, EDTA and Citric Acid Application on Nonfluorosed and Fluorosed Dentin: An In Vitro Study

    PubMed Central

    Sadanand, K.; Vandana, K. L.

    2016-01-01

    Fluorosis is one of the factors that may bring about mineralization changes in teeth. Routine treatment of root biomodification is commonly followed during Periodontal therapy. Background: The Purpose of the present study was to compare and evaluate the morphological changes in fluorosed and nonfluorosed root dentin subsequent to the application of Tetracycline, EDTA and Citric acid. Both fluorosed and nonfluorosed teeth comprising of periodontally healthy and diseased were included in this study. Method: Each of them was grouped into Tetracycline Hydrochloride, EDTA and Citric acid treatment groupes. Using scanning electron microscope (SEM), the photomicrographs of dentin specimens were obtained. Results: Showed that there was no significant difference in exposure of number of tubules in different groups, while significant increase in the tubular width and tubular surface area was seen in fluorosed healthy, followed by fluorosed diseased groups, nonfluorosed healthy and nonfluorosed diseased groups after root biomodification procedure using various root conditioning agents. The root biomodification procedure brings in definite difference between fluorosed and nonfluorosed dentin specimens. PMID:27335611

  16. Ablation of human carious dentin with a nanosecond pulsed laser at a wavelength of 5.85 μm: relationship between hardness and ablation depth

    NASA Astrophysics Data System (ADS)

    Ishii, Katsunori; Kita, Tetsuya; Yoshikawa, Kazushi; Yasuo, Kenzo; Yamamoto, Kazuyo; Awazu, Kunio

    2014-02-01

    Less invasive treatment and preservation of teeth, referred to as minimal intervention, are strong requirements in dentistry. In our previous study, the fundamental ablation properties of human dentin at wavelengths around 5.8 μm were investigated, and the results indicated that the wavelength of 5.85 μm was optimal for selective removal of carious dentin with less damage to normal dentin. The purpose of this study was to investigate the relationship between the ablation depth and hardness of human dentin including carious lesion. A nanosecond pulsed laser produced by difference-frequency generation was used for irradiations to human carious dentin. It was observed that correlation between ablation depth and Vickers hardness after 2 s laser irradiation at the wavelength of 5.85 μm and the average power density of 30 W/cm2. On the other hand, ablations did not depend on Vickers hardness at the wavelength of 6.00 μm. A nanosecond pulsed laser with the wavelength at 5.85 μm is useful for selective ablation of human carious dentin in accordance with the hardness.

  17. Influence of a glide path on the dentinal crack formation of ProTaper Next system

    PubMed Central

    Uzunoğlu, Emel

    2015-01-01

    Objectives The aim was to evaluate dentinal crack formation after root canal preparation with ProTaper Next system (PTN) with and without a glide path. Materials and Methods Forty-five mesial roots of mandibular first molars were selected. Fifteen teeth were left unprepared and served as controls. The experimental groups consist of mesiobuccal and mesiolingual root canals of remaining 30 teeth, which were divided into 2 groups (n = 15): Group PG/PTN, glide path was created with ProGlider (PG) and then canals were shaped with PTN system; Group PTN, glide path was not prepared and canals were shaped with PTN system only. All roots were sectioned perpendicular to the long axis at 1, 2, 3, 4, 6, and 8 mm from the apex, and the sections were observed under a stereomicroscope. The presence/absence of cracks was recorded. Data were analyzed with chi-square tests with Yates correction. Results There were no significant differences in crack formation between the PTN with and without glide path preparation. The incidence of cracks observed in PG/PTN and PTN groups was 17.8% and 28.9%, respectively. Conclusions The creation of a glide path with ProGlider before ProTaper Next rotary system did not influence dentinal crack formation in root canals. PMID:26587414

  18. Intentional retention of vital submerged roots in dogs.

    PubMed

    Plata, R L; Kelln, E E; Linda, L

    1976-07-01

    In this study, intact and untreated roots of twelve teeth in three dogs were submerged 2 mm. below the alveolar bone crest. On eight regeneration of alveolar bone was seen in 3 weeks, with complete bone coverage in 5 weeks. A complete lamina dura surrounded the buried roots, the original root canal tissue remained vital, and vessels and other structures now entered (or exited) from both ends. Cementum covered the cut end, making the end similar to a normal apex. Bone failed to regenerate completely over four of the twelve roots. Two of these had dentinal spicules which impeded complete bone coverage (Fig 9). Another was a case of delayed healing due to the early loss of sutures and subsequent infection where a sinus tract developed, connecting the oral environment with the resected root. This led to bone resorption and a partial pulp necrosis. In the fourth case the decreased depth of root burial and subsequent lack of bone cover led to external resorption of the cut dentin. Histologic examination after 12 weeks revealed the regeneration of bone, a regenerated periodontal membrane, and a layer of cementoblasts over the cut and exposed root dentin in a typical manner. This study suggests that when healthy bone and roots are present, particularly in an otherwise edentulous mandible retaining only a few nonrestorable anterior teeth, the roots can be retained in a nonpathologic state by means of a simple surgical technique. PMID:1065830

  19. Influence of light intensity on surface-free energy and dentin bond strength of single-step self-etch adhesives.

    PubMed

    Nojiri, Kie; Tsujimoto, Akimasa; Suzuki, Takayuki; Shibasaki, Syo; Matsuyoshi, Saki; Takamizawa, Toshiki; Miyazaki, Masashi

    2015-01-01

    In this study, we investigated the influence of light intensity on the surface-free energy and dentin bond strength of single-step selfetch adhesives. The adhesives were applied to the dentin surfaces of bovine mandibular incisors and cured with light intensities of 0 (no irradiation), 200, 400, and 600 mW/cm(2). Surface-free energies were determined by measuring the contact angles of three test liquids placed on the cured adhesives. Dentin bond strengths of the specimens were also measured. Polymerization with a higher light intensity resulted in a lower surface-free energy of the cured adhesives. The greatest bond strength was achieved when a light intensity of 400 mW/cm(2) or greater was used. Our data suggest that the surface-free energy and dentin bond strength of single-step self-etch adhesives are affected by light intensity of the curing unit. PMID:26438984

  20. The effects of extracts of chewing sticks (Salvadora persica) on healthy and periodontally involved human dentine: a SEM study.

    PubMed

    Almas, K

    2001-01-01

    The popularity and availability of chewing sticks (Salvadora persica) in the Asia, Middle East and Africa make them a commonly used oral hygiene tool in those societies. Salvador persica chewing stick called miswak is frequently used in Saudi Arabia. The antimicrobial effects of miswak has been well documented. The aim of this study is to find our the effect of aqueous extracts of miswak on healthy and periodontally involved human dentine with Scanning Electron Microscopy (SEM) in vitro. 25% aqueous extract of freshly prepared miswak solution was used for the study. Twelve human premolars teeth (6 healthy and 6 with periodontal disease) recently extracted for orthodontic and periodontal reasons were used. 24 SEM specimens were prepared and treated with miswak extract with different conditions e.g. soaking and burnishing with miswak extract. Soaking the healthy and periodontally diseased root dentine in miswak extract resulted in partial removal of smear layer and occlusion of dentinal tubules was observed in dentine specimens burnished with miswak solution. Further research is needed to evaluate the effect of aqueous extract of miswak on etched human dentine at higher concentrations. PMID:11808063

  1. Scanning electron microscopy and thermal characteristics of dentin ablated by a short-pulse XeCl excimer laser.

    PubMed

    Neev, J; Stabholtz, A; Liaw, L H; Torabinejad, M; Fujishige, J T; Ho, P D; Berns, M W

    1993-01-01

    The interaction of a short pulse XeCl excimer laser radiation with human dentin was investigated. The dependence of surface temperatures and temperature gradients into the treated teeth on laser parameters such as fluence (0.5J/cm2-7J/cm2), pulse repetition rate (1Hz-35Hz), and spot size (0.004cm2-0.12cm2) was studied. Additionally, the effect of fluence and pulse repetition rate on dentin microstructure was studied using scanning electron microscopy (SEM). It is demonstrated that this "cold ablation" excimer laser can result in significant thermal modification in the dentin surfaces. Changes include the formation of melted dentin grains, which uniformly cover the surface and the exposed dentin tubules. Maximum temperatures of the ablated surfaces, however, remained relatively low at most laser parameters used. Also, the immediate neighborhood of the root canal was essentially undisturbed at most laser parameters. These observations suggest that with the appropriate choice of parameters XeCl lasers can be effective in producing surface structures that may prove useful in enhancing bond strength or other applications in dentistry, without exposing tooth pulp to significant temperature elevation. PMID:8515674

  2. Fate of HERS during Tooth Root Development

    PubMed Central

    Huang, Xiaofeng; Bringas, Pablo; Slavkin, Harold C.; Chai, Yang

    2009-01-01

    Tooth root development begins after the completion of crown formation in mammals. Previous studies have shown that Hertwig's epithelial root sheath (HERS) plays an important role in root development, but the fate of HERS has remained unknown. In order to investigate the morphological fate and analyze the dynamic movement of HERS cells in vivo, we generated K14-Cre;R26R mice. HERS cells are detectable on the surface of the root throughout root formation and do not disappear. Most of the HERS cells are attached to the surface of the cementum, and others separate to become the epithelial rest of Malasez. HERS cells secrete extracellular matrix components onto the surface of the dentin before dental follicle cells penetrate the HERS network to contact dentin. HERS cells also participate in the cementum development and may differentiate into cementocytes. During root development, the HERS is not interrupted, and instead the HERS cells continue to communicate with each other through the network structure. Furthermore, HERS cells interact with cranial neural crest derived mesenchyme to guide root development. Taken together, the network of HERS cells is crucial for tooth root development. PMID:19576204

  3. Long-term effect of carbodiimide on dentin matrix and resin-dentin bonds

    PubMed Central

    Bedran-Russo, Ana Karina B.; Vidal, Cristina M.P.; Dos Santos, Paulo H.; Castellan, Carina S.

    2010-01-01

    Objectives To characterize the interaction of 1-Ethyl-3-[3-dimethylaminopropyl] carbodiimide Hydrochloride (EDC) with dentin matrix and its effect on the resin-dentin bond. Methods Changes to the stiffness of demineralized dentin fragments treated with EDC/N-hydroxysuccinimide (NHS) in different solutions were evaluated at different time points. The resistance against enzymatic degradation was indirectly evaluated by ultimate tensile strength (UTS) test of demineralized dentin treated or not with EDC/NHS and subjected to collagenase digestion. Short- and long-term evaluations of the strength of resin-dentin interfaces treated with EDC/NHS for 1 hour were performed using microtensile bond strength (µTBS) test. All data (MPa) were individually analyzed using ANOVA and Tukey HSD tests (α=0.05). Results The different exposure times significantly increased the stiffness of dentin (p<0.0001, control - 5.15 and EDC/NHS - 29.50), while no differences were observed among the different solutions of EDC/NHS (p=0.063). Collagenase challenge did not affect the UTS values of EDC/NHS group (6.08) (p>0.05), while complete degradation was observed for the control group (p=0.0008, control - 20.84 and EDC/NHS - 43.15). EDC/NHS treatment did not significantly increase resin-dentin µTBS, but the values remained stable after 12 months water storage (p<0.05). Conclusions Biomimetic use of EDC/NHS to induce exogenous collagen cross-links resulted in increased mechanical properties and stability of dentin matrix and dentin-resin interfaces. PMID:20524201

  4. Plasma treatment of dentin surfaces for improving self-etching adhesive/dentin interface bonding

    PubMed Central

    Dong, Xiaoqing; Li, Hao; Chen, Meng; Wang, Yong; Yu, Qingsong

    2015-01-01

    This study is to evaluate plasma treatment effects on dentin surfaces for improving self-etching adhesive and dentin interface bonding. Extracted unerupted human third molars were used after crown removal to expose dentin. One half of each dentin surface was treated with atmospheric non-thermal argon plasmas, while another half was untreated and used as the same tooth control. Self-etching adhesive and universal resin composite was applied to the dentin surfaces as directed. After restoration, the adhesive-dentin bonding strength was evaluated by micro-tensile bonding strength (μTBS) test. Bonding strength data was analyzed using histograms and Welch’s t-test based on unequal variances. μTBS test results showed that, with plasma treatment, the average μTBS value increased to 69.7±11.5 MPa as compared with the 57.1±17.5 MPa obtained from the untreated controls. After 2 months immersion of the restored teeth in 37 °C phosphate buffered saline (PBS), the adhesive-dentin bonding strengths of the plasma-treated specimens slightly decreased from 69.7±11.5 MPa to 63.9±14.4 MPa, while the strengths of the untreated specimens reduced from 57.1±17.5 MPa to 48.9±14.6 MPa. Water contact angle measurement and scanning electron microscopy (SEM) examination verified that plasma treatment followed by water rewetting could partially open dentin tubules, which could enhance adhesive penetration to form thicker hybrid layer and longer resin tags and consequently improve the adhesive/dentin interface quality. PMID:26273561

  5. On the pulpal nerve supply in primary human teeth: evidence for the innervation of primary dentine.

    PubMed

    Egan, C A; Hector, M P; Bishop, M A

    1999-03-01

    The presence of nerves in human tooth pulp has been recognized for over a hundred years, and the innervation of dentine for about 40 years. These observations have been made in permanent teeth. Very few studies have reported on the innervation of the primary pulp and dentine. The purpose of this study was to describe the innervation of the primary tooth pulp-dentine complex. Ten mature primary teeth (one incisor, six canines and three molars) were used. Immediately following extraction they were divided into three sections using a diamond disc and saline coolant. They were then immersion fixed in a solution of formaldehyde and picric acid dissolved in a phosphate buffer pH 7.4). The teeth were then demineralized for 1-3 weeks in formic acid. Following complete demineralization, 30 microns sections were cut on a freezing microtome. Neural tissue was stained using a specific antibody to calcitonin gene related peptide (CGRP). Sections were mounted on glass slides and examined using light microscopy. No individual nerve fibres were seen in the control sections, suggesting that the method used was specific for CGRP-containing nerve fibres. The primary teeth appeared to be well innervated. Myelinated and unmyelinated nerves were seen. There was a dense but variable subodontoblastic plexus of nerves (plexus of Raschkow) and nerve fibres were seen to leave this to travel towards the odontoblast layer. Most terminated here, but a few penetrated the odontoblast layer to enter predentine and the dentine tubules. The maximum penetration was 125 microns but most terminated within 30 microns of the dentinopulpal junction. The coronal region was more densely innervated than the root. Within the crown the cervical third was the most densely innervated region, followed by the pulp horn and the middle third. In conclusion, this study has demonstrated that mature primary tooth contains a pulp which is well innervated and has many nerve endings terminating in or near the odontoblast

  6. Relative biological effectiveness of fission neutrons for producing micronuclei in the root-tip cells of onion seedlings after irradiation as dry seeds.

    PubMed

    Zhang, Wenyi; Endo, Satoru; Ishikawa, Masayori; Ikeda, Hideo; Hoshi, Masaharu

    2002-12-01

    The relative biological effectiveness (RBE) of mixed neutron and gamma-ray radiation emitted at a 252Cf source at the Research Institute for Radiation Biology and Medicine, Hiroshima University, compared with 60Co gamma-ray radiation was determined. The tissue-absorbed dose contribution of the accompanying gamma radiation was about 35.7% to the total tissue-absorbed dose from the 252Cf mixed radiation. The 252Cf mixed radiation and 60Co gamma rays produced approximate linear changes in the frequency of micronuclei induced in root-tip cells of Allium cepa L. onion seedlings after irradiation as dry dormant seeds with varying absorbed doses in onion seeds. Therefore, the RBE for radiation-induced micronuclei was calculated as the ratio of the slopes for the 252Cf mixed radiation and the 60Co gamma rays. The deduced RBE value of 252Cf mixed radiation to 60Co gamma rays to induce micronuclei in dry dormant onion seed cells was about 90.5 +/- 3.6 (+/- 1sigma); the RBE of neutrons from the 252Cf mixed radiation was about 150 +/- 6 (+/- 1sigma). Furthermore, the sensitivity ratio of the induction rate of micronuclei in dry dormant seeds to that in seedlings by neutrons from 252Cf mixed radiation was significantly different from that by 60Co gamma rays. From these results, we concluded that the repair efficiency of DNA damage induced by neutrons may be different from that by gamma rays. PMID:12674204

  7. Energy-dependent RBE of neutrons to induce micronuclei in root-tip cells of Allium cepa onion irradiated as dry dormant seeds and seedlings.

    PubMed

    Zhang, Wenyi; Fujikawa, Kazuo; Endo, Satoru; Ishikawa, Masayori; Ohtaki, Megu; Ikeda, Hideo; Hoshi, Masaharu

    2003-06-01

    The relative biological effectiveness (RBE) of various energy neutrons produced from a Schenkel-type accelerator at the Research Institute for Radiation Biology and Medicine, Hiroshima University (HIRRAC), compared with 60Co gamma-ray radiation was determined. The neutron radiations and gamma-ray radiation produced good linear changes in the frequency of micronuclei induced in the root-tip cells of Allium cepa onion irradiated as dry dormant seeds (seed assay) and seedlings (seedling assay) with varying radiation doses. Therefore the RBE for radiation-induced micronuclei can be calculated as the ratio of the slopes of the fitted linear dose response for the neutron radiations and the 60Co gamma-ray radiation. The RBE values by seed assay and seedling assay decreased to 174 +/- 7, from 216 +/- 9, and to 31.4 +/- 1.0, from 45.3 +/- 1.3 (one standard error), respectively, when neutron energies increased to 1.0 MeV, from 0.2 MeV, in the present study. Furthermore, the ratio of the micronucleus induction rates of seed assay to seedling assay by gamma-ray radiation was much lower than that by neutron radiations. PMID:13678347

  8. Dentine microhardness after different methods for detection and removal of carious dentine tissue

    PubMed Central

    MOLLICA, Fernanda Brandão; TORRES, Carlos Rocha Gomes; GONÇALVES, Sergio Eduardo de Paiva; MANCINI, †Maria Nadir Gasparoto

    2012-01-01

    There are several methods for identifying carious dentinal tissue aiming to avoid removal of healthy dentinal tissue. Objectives The purpose of this study was to test different methods for the detection of carious dentinal tissue regarding the amount of carious tissue removed and the remaining dentin microhardness after caries removal. Material and methods The dentin surfaces of 20 bovine teeth were exposed and half of the surface was protected with nail polish. Cariogenic challenge was performed by immersion in a demineralizing solution for 14 days. After transverse cross-section of the crown, the specimens were divided into four groups (n=10), according to the method used to identify and remove the carious tissue: "Papacárie", Caries-detector dye, DIAGNOdent and Tactile method. After caries removal, the cross-sectional surface was included in acrylic resin and polished. In a microhardness tester, the removed dentin thickness and the Vickers microhardness of the following regions were evaluated: remaining dentin after caries removal and superficial and deep healthy dentin. Results ANOVA and Tukey's test (α=0.05) were performed, except for DIAGNOdent, which did not detect the presence of caries. Results for removed dentin thickness were: "Papacárie" (424.7±105.0; a), Caries-detector dye (370.5±78.3; ab), Tactile method (322.8±51.5; bc). Results for the remaining dentin microhardness were: "Papacárie" (42.2±10.5; bc), Caries-detector dye (44.6±11.8; abc), Tactile method (24.3±9.0; d). Conclusions DIAGNOdent did not detect the presence of carious tissue; Tactile method and "Papacárie" resulted in the least and the most dentinal thickness removal, respectively; Tactile method differed significantly from "Papacárie" and Caries-detector dye in terms of the remaining dentin microhardness, and Tactile method was the one which presented the lowest microhardness values. PMID:23032207

  9. Dentin Matrix Proteins in Bone Tissue Engineering

    PubMed Central

    Ravindran, Sriram

    2016-01-01

    Dentin and bone are mineralized tissue matrices comprised of collagen fibrils and reinforced with oriented crystalline hydroxyapatite. Although both tissues perform different functionalities, they are assembled and orchestrated by mesenchymal cells that synthesize both collagenous and noncollagenous proteins albeit in different proportions. The dentin matrix proteins (DMPs) have been studied in great detail in recent years due to its inherent calcium binding properties in the extracellular matrix resulting in tissue calcification. Recent studies have shown that these proteins can serve both as intracellular signaling proteins leading to induction of stem cell differentiation and also function as nucleating proteins in the extracellular matrix. These properties make the DMPs attractive candidates for bone and dentin tissue regeneration. This chapter will provide an overview of the DMPs, their functionality and their proven and possible applications with respect to bone tissue engineering. PMID:26545748

  10. Influence of oxygen inhibition on the surface free-energy and dentin bond strength of self-etch adhesives.

    PubMed

    Koga, Kensaku; Tsujimoto, Akimasa; Ishii, Ryo; Iino, Masayoshi; Kotaku, Mayumi; Takamizawa, Toshiki; Tsubota, Keishi; Miyazaki, Masashi

    2011-10-01

    We compared the surface free-energies and dentin bond strengths of single-step self-etch adhesives with and without an oxygen-inhibited layer. The labial dentin surfaces of bovine mandibular incisors were wet ground with #600-grit silicon carbide paper. The adhesives were applied to the ground dentin, light-irradiated, and the oxygen-inhibited layer was either retained or removed with ethanol. The surface free-energies were determined by measuring the contact angles of three test liquids placed on the cured adhesives. The dentin bond strengths of specimens with and without the oxygen-inhibited layer were measured. For all surfaces, the value of the estimated surface tension component was relatively constant at 35.5-39.8 mJ m(-2) . The value of the , Lewis acid component increased slightly when the oxygen-inhibited layer was removed, whereas that of the , Lewis base component decreased significantly. The bond strengths of the self-etch adhesives were significantly lower in specimens without an oxygen-inhibited layer (13.2-13.6 MPa) than in those with an oxygen-inhibited layer (17.5-18.4 MPa). These results indicate that the presence of an oxygen-inhibited layer in single-step self-etch adhesives with advanced photoinitiators promotes higher dentin bond strength. PMID:21896057

  11. Temperature Rise during Primer, Adhesive, and Composite Resin Photopolymerization of a Low-Shrinkage Composite Resin under Caries-Like Dentin Lesions.

    PubMed

    Mousavinasab, Sayed-Mostafa; Khoroushi, Maryam; Moharreri, Mohammadreza

    2012-01-01

    Objective. This study evaluated temperature rise of low-shrinkage (LS) self-etch primer (P), LS self-etch adhesive (A), and P90 silorane-based composite resin systems, photopolymerized under normal and artificially demineralized dentin. Methods. Forty 1.5 mm-thick dentin discs were prepared from sound human molars, half of which were demineralized. Temperature rise was measured during photopolymerization using a K-type thermocouple under the discs: 10 s and 40 s irradiation of the discs (controls/groups 1 and 2); 10 s irradiation of primer (P), 10 s irradiation of adhesive (A), 40 s irradiation of P90 without P and A, and 40 s irradiation of P90 with P and A (groups 3 to 6, resp.). The samples were photopolymerized using an LED unit under 550 mW/cm(2) light intensity. Data was analyzed using repeated measures ANOVA and paired-sample t-test (α = 0.05). Results. There were no significant differences in temperature rise means between the two dentin samples for each irradiation duration (P > 0.0001), with significant differences between the two irradiation durations (P > 0.0001). Temperature rise measured with 40 s irradiation was significantly higher than that of 10 s duration for undemineralized and demineralized dentin P < 0.0001). Conclusions. Light polymerization of P90 low-shrinkage composite resin resulted in temperature rise approaching threshold value under artificially demineralized and undemineralized dentin. PMID:23320185

  12. Effects of adsorbed and templated nanosilver in mesoporous calcium-silicate nanoparticles on inhibition of bacteria colonization of dentin

    PubMed Central

    Fan, Wei; Wu, Daming; Tay, Franklin R; Ma, Tengjiao; Wu, Yujie; Fan, Bing

    2014-01-01

    Mesoporous calcium-silicate nanoparticles (MCSNs) are advanced biomaterials for controlled drug delivery and mineralization induction. Nanosilver-incorporated MCSNs (Ag-MCSNs) were prepared in the present study using both the adsorption and template methods. Both versions of Ag-MCSNs showed characteristic morphology of mesoporous materials and exhibited sustained release of ions over time. In antibacterial testing against planktonic Enterococcus faecalis, Ag-MCSNs showed significantly better antibacterial effects when compared with MCSNs (P<0.05). The Ag-MCSNs aggregated on the dentin surface of root canal walls and infiltrated into dentinal tubules after ultrasound activation, significantly inhibiting the adherence and colonization of E. faecalis on dentin (P<0.05). Despite this, Ag-MCSNs with templated nanosilver showed much lower cytotoxicity than Ag-MCSNs with adsorbed nanosilver (P<0.05). The results of the present study indicated that nanosilver could be incorporated into MCSNs using the template method. The templated nanosilver could release silver ions and inhibit the growth and colonization of E. faecalis both in the planktonic form and as biofilms on dentin surfaces as absorbed nanosilver. Templated Ag-MCSNs may be developed into a new intracanal disinfectant for root canal disinfection due to their antibacterial ability and low cytotoxicity, and as controlled release devices for other bioactive molecules to produce multifunctional biomaterials. PMID:25419127

  13. Clinical Efficacy of Fluoride Varnish and Low-Level Laser Radiation in Treating Dentin Hypersensitivity.

    PubMed

    Dantas, Euler Maciel; Amorim, Fernanda Kyarelly de Oliveira; Nóbrega, Fernando José de Oliveira; Dantas, Poliana Medeiros Cunha; Vasconcelos, Rodrigo Gadelha; Queiroz, Lélia Maria Guedes

    2016-02-01

    The objective of this study was to compare the efficacy of fluoride varnish (Fluorniz(r)) and irradiation with a gallium-arsenide-aluminum diode laser in the treatment of cervical dentin hypersensitivity. Cervical dentin hypersensitivity (CDH) is a painful condition that is highly prevalent in the world's adult population, with one in six patients presenting this symptom. Eighty-six teeth were divided into two groups: Group 1, teeth treated with Fluorniz; Group 2, teeth irradiated with a GaAlAs laser at a 4 J/cm2 dose. The two treatments were applied to the buccal cervical region in four sessions, at intervals of 72 to 96 h. The response of the patient to tactile and thermal-evaporative stimuli was rated on a visual analog scale. The results showed a reduction of hypersensitivity in response to tactile and thermal-evaporative stimulation at the end of treatment in both groups. In conclusion, short-term treatment with Fluorniz was found to be more effective than low-level laser radiation in reducing cervical dentin hypersensitivity. PMID:27007351

  14. Free-electron-laser (FEL)-induced desorption of ions from tooth dentine

    NASA Astrophysics Data System (ADS)

    Ogino, Seiji; Awazu, Kunio; Tomimasu, Takio

    1997-05-01

    Free electron laser (FEL) with the wide wavelength tunability has been developed and used for various applications. The FEL gives high efficiency for the photo- induced ablation when the laser is tuned to an absorption maximum of the target. This study investigates the FEL induced desorption of ions from tooth dentine to find new possibility for laser dentistry. The FEL was tuned to 9.4 (Mu) m, which is an absorption maximum of phosphoric acid ion known as major component of dentine. The FEL pulse length was several ps. The output average power was varied from 5 to 20mW by filters. A time-of-flight mass spectroscopy systems were developed for the purpose of analyzing the desorbed ions of varying masses. After the 9.4 micrometers FEL irradiation, the dentine surface was ablated, and visible light emission was observed. As a result, positive ions which correspond to Na+ and many phosphoric acid ions were measured. The positive ions, however were not observed when the FEL was not tuned to the absorption peak of the target. Therefore, this wavelength dependence points to resonant multiphoton vibrational excitation of molecules by the 9.4 micrometers FEL irradiation.

  15. Mechanical characterization of proanthocyanidin-dentin matrix interaction

    PubMed Central

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

    2010-01-01

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

  16. Ultimate tensile strength of dentin: Evidence for a damage mechanics approach to dentin failure.

    PubMed

    Staninec, Michal; Marshall, Grayson W; Hilton, Joan F; Pashley, David H; Gansky, Stuart A; Marshall, Sally J; Kinney, John H

    2002-01-01

    Dentin structure and properties are known to vary with orientation and location. The present study explored the variation in the ultimate tensile strength (UTS) of dentin with location in the tooth. Hourglass specimens were prepared from dentin located in the center, under cusps, and in the cervical regions of human molar teeth. These were tested in tension at various distances from the pulp. Median tensile strengths ranged from 44.4 MPa in the inner dentin near the pulp, to 97.8 MPa near the dentino-enamel junction (DEJ). This increase in the median UTS with distance from the pulp to the DEJ was statistically significant (P <.001). Of particular importance was the observation that the UTS measurements followed a Weibull probability distribution, with a Weibull modulus of about 4.5. The Weibull behavior of the UTS data strongly suggests that the large variances in fracture strength data result from a distribution of preexisting defects in the dentin. These findings justify a damage-mechanics approach to studies of dentin failure. PMID:12115767

  17. Tooth Bleaching Increases Dentinal Protease Activity

    PubMed Central

    Sato, C.; Rodrigues, F.A.; Garcia, D.M.; Vidal, C.M.P.; Pashley, D.H.; Tjäderhane, L.; Carrilho, M.R.; Nascimento, F.D.; Tersariol, I.L.S.

    2012-01-01

    Hydrogen peroxide is an oxidative agent commonly used for dental bleaching procedures. The structural and biochemical responses of enamel, dentin, and pulp tissues to the in vivo bleaching of human (n = 20) premolars were investigated in this study. Atomic force microscopy (AFM) was used to observe enamel nanostructure. The chemical composition of enamel and dentin was analyzed by infrared spectroscopy (FTIR). The enzymatic activities of dental cathepsin B and matrix metalloproteinases (MMPs) were monitored with fluorogenic substrates. The amount of collagen in dentin was measured by emission of collagen autofluorescence with confocal fluorescence microscopy. The presence of Reactive Oxygen Species (ROS) in the pulp was evaluated with a fluorogenic 2′,7′-dichlorodihydrofluorescein diacetate (DCFDA) probe. Vital bleaching of teeth significantly altered all tested parameters: AFM images revealed a corrosion of surface enamel nanostructure; FTIR analysis showed a loss of carbonate and proteins from enamel and dentin, along with an increase in the proteolytic activity of cathepsin-B and MMPs; and there was a reduction in the autofluorescence of collagen and an increase in both cathepsin-B activity and ROS in pulp tissues. Together, these results indicate that 35% hydrogen peroxide used in clinical bleaching protocols dramatically alters the structural and biochemical properties of dental hard and soft pulp tissue. PMID:23242228

  18. Bonding amalgam to dentin by different methods.

    PubMed

    Hadavi, F; Hey, J H; Strasdin, R B; McMeekin, G P

    1994-09-01

    The shear bond strengths of amalgam to dentin by use of (1) All-Bond-2 adhesive, (2) Amalgambond Plus adhesive and (3) TMS Minim pins were compared in this study. Forty-five sound human molars were mounted in acrylic resin and randomly assigned to one of the three groups. The occlusal surfaces were ground to expose the dentin, which was then wet-polished with 600-grit sand paper. All materials were applied according to manufacturer's instructions. A split die with a 5 mm opening was placed and amalgam was condensed, which created an amalgam cylinder bonded/retained to the dentin surface. A shear bond force was applied to the base of the amalgam cylinder. The data were analyzed with analysis of variance and Scheffé's test at the 95% level. All systems were found to promote adhesion/retention of amalgam to dentin. The All-Bond 2 group showed significantly higher bond strength (11.106 +/- 3.585 MPa) than Amalgambond Plus (6.343 +/- 3.564 MPa) and TMS pin (6.868 +/- 0.794 MPa) (p < 0.05). PMID:7965897

  19. Dentin Biomodification Potential Depends on Polyphenol Source

    PubMed Central

    Aguiar, T.R.; Vidal, C.M.P.; Phansalkar, R.S.; Todorova, I.; Napolitano, J.G.; McAlpine, J.B.; Chen, S.N.; Pauli, G.F.; Bedran-Russo, A.K.

    2014-01-01

    Although proanthocyanidins (PACs) modify dentin, the effectiveness of different PAC sources and the correlation with their specific chemical composition are still unknown. This study describes the chemical profiling of natural PAC-rich extracts from 7 plants using ultra high pressure/performance liquid chromatography (UHPLC) to determine the overall composition of these extracts and, in parallel, comprehensively evaluate their effect on dentin properties. The total polyphenol content of the extracts was determined (as gallic acid equivalents) using Folin-Ciocalteau assays. Dentin biomodification was assessed by the modulus of elasticity, mass change, and resistance to enzymatic biodegradation. Extracts with a high polyphenol and PAC content from Vitis vinifera, Theobroma cacao, Camellia sinensis, and Pinus massoniana induced a significant increase in modulus of elasticity and mass. The UHPLC analysis showed the presence of multiple types of polyphenols, ranging from simple phenolic acids to oligomeric PACs and highly condensed tannins. Protective effect against enzymatic degradation was observed for all experimental groups; however, statistically significant differences were observed between plant extracts. The findings provide clear evidence that the dentin bioactivities of PACs are source dependent, resulting from a combination of concentration and specific chemical constitution of the complex PAC mixtures. PMID:24574140

  20. Dentin biomodification potential depends on polyphenol source.

    PubMed

    Aguiar, T R; Vidal, C M P; Phansalkar, R S; Todorova, I; Napolitano, J G; McAlpine, J B; Chen, S N; Pauli, G F; Bedran-Russo, A K

    2014-04-01

    Although proanthocyanidins (PACs) modify dentin, the effectiveness of different PAC sources and the correlation with their specific chemical composition are still unknown. This study describes the chemical profiling of natural PAC-rich extracts from 7 plants using ultra high pressure/performance liquid chromatography (UHPLC) to determine the overall composition of these extracts and, in parallel, comprehensively evaluate their effect on dentin properties. The total polyphenol content of the extracts was determined (as gallic acid equivalents) using Folin-Ciocalteau assays. Dentin biomodification was assessed by the modulus of elasticity, mass change, and resistance to enzymatic biodegradation. Extracts with a high polyphenol and PAC content from Vitis vinifera, Theobroma cacao, Camellia sinensis, and Pinus massoniana induced a significant increase in modulus of elasticity and mass. The UHPLC analysis showed the presence of multiple types of polyphenols, ranging from simple phenolic acids to oligomeric PACs and highly condensed tannins. Protective effect against enzymatic degradation was observed for all experimental groups; however, statistically significant differences were observed between plant extracts. The findings provide clear evidence that the dentin bioactivities of PACs are source dependent, resulting from a combination of concentration and specific chemical constitution of the complex PAC mixtures. PMID:24574140

  1. Observations on pulpal response to carbon dioxide laser drilling of dentine in healthy human third molars.

    PubMed

    Nair, P N R; Baltensperger, M; Luder, H U; Eyrich, G K H

    2005-01-01

    Preservation of pulpal health is the primary prerequisite for successful application of laser systems in the hard tissue management of vital teeth. The purpose of this study was to investigate the short and long-term pulpal effects to cavity preparations in healthy human teeth using carbon dioxide (CO2) laser. A total of seven, healthy, third molars that were scheduled to be removed due to space problems were used. After the laser drilling, the occlusal cavities were closed temporarily, and the teeth were extracted 7 days (n=5) and 3 months (n=2) after the operation. The specimens were fixed, decalcified, subdivided and processed for light and transmission electron microscopy. Seven days postoperatively all the five teeth that had been irradiated with the CO2 laser did not reveal any pathological changes in the pulpo-dentine complex. Three months postoperatively the two teeth that were prepared with the laser showed subtle but distinct apposition of tertiary dentine that was lined with intact odontoblasts. One of the specimens at 3 months revealed the presence of a mild, but very circumscribed, pulpal infiltration of chronic inflammatory cells subjacent to the cavity preparation. The latter is unlikely to be due to a direct effect of the laser irradiation but a possible consequence of microleakage of oral antigens and/or other tissue-irritating molecules through the temporary restoration and the remaining dentine thickness (RDT). Although these preliminary histological results suggest that the CO2 laser under investigation induced only minimal response of the dentine-pulp complex when used as a hard-tissue drilling tool, with specific energy settings, pulse duration within thermal relaxation time and emitting radiations at 9.6 microm of wavelength, larger clinical trials involving various types of teeth are necessary to reach definite conclusions for large-scale clinical application of the laser device. PMID:15647971

  2. Comparative in vitro SEM study of a novel root canal irrigant-MTAD and conventional root biomodifiers on periodontally involved human teeth

    PubMed Central

    Tandon, Charu; Govila, Vivek; Pant, Vandana Aditya; Meenawat, Ajita

    2015-01-01

    Background: Smear layer removal and collagen fiber exposure may improve regeneration which can be accomplished by use of root biomodifiers. These enhance the degree of connective tissue attachment to denuded roots. The objective of this in vitro study was to evaluate and compare novel root canal irrigant and other root biomodifiers for smear layer removal on periodontally involved human teeth. Materials and Methods: Forty human teeth were collected and stored in saline. After scaling and root planing, two samples were obtained from each tooth. Thus, a total of 80 dentin blocks were randomly divided into four groups: Mixture of tetracycline, acid and detergent (MTAD), tetracycline hydrochloride (TTC HCl), citric acid (CA), and ethylenediaminetetraacetic acid (EDTA). The agents were applied for 3 min by active burnishing. Immediately following treatment, the specimens were rinsed, dehydrated, fixed and prepared for scanning electron microscope and were examined at × 3500 magnification. Sampaio's index was evaluated by the previously trained blind examiner using photomicrographs. Groups were compared using analysis of variance followed by Tukey's post-hoc test. Results: Mixture of tetracycline, acid, and detergent is most efficacious in removing the smear layer and showed statistically significant dentinal tubules opening, followed by EDTA, TTC HCl, and CA. Conclusion: Mixture of tetracycline, acid and detergent and conventional root biomodifiers used in the study alters the dentin surface by smear layer removal and exposure of dentinal tubules. Hence, MTAD as a root biomodifier may have a significant role in periodontal regeneration. PMID:26229265

  3. Bovine and equine peritubular and intertubular dentin.

    PubMed

    Stock, S R; Deymier-Black, A C; Veis, A; Telser, A; Lux, E; Cai, Z

    2014-09-01

    Dentin contains 1-2μm diameter tubules extending from the pulp cavity to near the junction with enamel. Peritubular dentin (PTD) borders the tubule lumens and is surrounded by intertubular dentin (ITD). Differences in PTD and ITD composition and microstructure remain poorly understood. Here, a (∼200nm)(2), 10.1keV synchrotron X-ray beam maps X-ray fluorescence and X-ray diffraction simultaneously around tubules in 15-30μm thick bovine and equine specimens. Increased Ca fluorescence surrounding tubule lumens confirms that PTD is present, and the relative intensities in PTD and ITD correspond to carbonated apatite (cAp) volume fraction of ∼0.8 in PTD vs. 0.65 assumed for ITD. In the PTD near the lumen edges, Zn intensity is strongly peaked, corresponding to a Zn content of ∼0.9mgg(-1) for an assumed concentration of ∼0.4mgg(-1) for ITD. In the equine specimen, the Zn K-edge position indicates that Zn(2+) is present, similar to bovine dentin (Deymier-Black et al., 2013), and the above edge structure is consistent with spectra from macromolecules related to biomineralization. Transmission X-ray diffraction shows only cAp, and the 00.2 diffraction peak (Miller-Bravais indices) width is constant from ITD to the lumen edge. The cAp 00.2 average preferred orientation is axisymmetric (about the tubule axis) in both bovine and equine dentin, and the axisymmetric preferred orientation continues from ITD through the PTD to the tubule lumen. These data indicate that cAp structure does not vary from PTD to ITD. PMID:24911530

  4. A Case of Dentinogenesis Imperfecta Treated with Submerged Root Technique

    PubMed Central

    Chandar, Bhanu; Srilakshmi, J.; Khaitan, Tanya; Babu, B. Balaji

    2015-01-01

    Dentinogenesis imperfecta (DGI), an autosomal dominant trait, is one of the most common hereditary disorders affecting both the formation and mineralization of dentin. Either or both primary and permanent dentition is affected by it. Here, we present a case report of a 13-year-old female patient affected with DGI who had undergone prosthetic rehabilitation with submerged root technique. PMID:26501025

  5. Surface microanalysis and chemical imaging of early dentin remineralization.

    PubMed

    Toledano, Manuel; Cabello, Inmaculada; Vílchez, Miguel Angel Cabrerizo; Fernández, Miguel Angel; Osorio, Raquel

    2014-02-01

    This study reports physical and chemical changes that occur at early dentin remineralization stages. Extracted human third molars were sectioned to obtain dentin discs. After polishing the dentin surfaces, three groups were established: (1) untreated dentin (UD), (2) 37% phosphoric acid application for 15 s (partially demineralized dentin-PDD), and (3) 10% phosphoric acid for 12 h at 25° C (totally demineralized dentin-TDD). Five different remineralizing solutions were used: chlorhexidine (CHX), artificial saliva (AS), phosphate solution (PS), ZnCl2, and ZnO. Wettability (contact angle), ζ potential and Raman spectroscopy analysis were determined on dentin surfaces. Demineralization of dentin resulted in a higher contact angle. Wettability decreased after immersion in all solutions. ζ potential analysis showed dissimilar performance ranging from -6.21 mV (TDD + AS) up to 3.02 mV (PDD + PS). Raman analysis showed an increase in mineral components after immersing the dentin specimens, in terms of crystallinity, mineral content, and concentration. This confirmed the optimal incorporation and deposition of mineral on dentin collagen. Organic content reflected scarce changes, except in TDD that appeared partially denatured. Pyridinium, as an expression of cross-linking, appeared in all spectra except in specimens immersed in PS. PMID:24160361

  6. Dynamic intratubular biomineralization following root canal obturation with pozzolan-based mineral trioxide aggregate sealer cement.

    PubMed

    Yoo, Yeon-Jee; Baek, Seung-Ho; Kum, Kee-Yeon; Shon, Won-Jun; Woo, Kyung-Mi; Lee, WooCheol

    2016-01-01

    The application of mineral trioxide aggregates (MTA) cement during the root canal obturation is gaining concern due to its bioactive characteristic to form an apatite in dentinal tubules. In this regard, this study was to assess the biomineralization of dentinal tubules following root canal obturation by using pozzolan-based (Pz-) MTA sealer cement (EndoSeal MTA, Maruchi). Sixty curved roots (mesiobuccal, distobuccal) from human maxillary molars were instrumented and prepared for root canal obturation. The canals were obturated with gutta-percha (GP) and Pz-MTA sealer by using continuous wave of condensation technique. Canals obturated solely with ProRoot MTA (Dentsply Tulsa Dental) or Pz-MTA sealer were used for comparison. In order to evaluate the biomineralization ability under different conditions, the PBS pretreatment before the root canal obturation was performed in each additional samples. At dentin-material interfaces, the extension of intratubular biomineralization was analyzed using scanning electron microscopy (SEM) and energy dispersive spectroscopy. When the root canal was obturated with GP and Pz-MTA sealer, enhanced biomineralization of the dentinal tubules beyond the penetrated sealer tag was confirmed under the SEM observation (p < 0.05). Mineralized apatite structures (calcium/phosphorous ratio, 1.45-1.89) connecting its way through the dentinal tubules were detected at 350-400 μm from the tubule orifice, and the pre-crystallization seeds were also observed along the intra- and/or inter-tubular collagen fiber. Intratubular biomineralization depth was significantly enhanced in all PBS pretreated canals (p < 0.05). Pz-MTA cement can be used as a promising bioactive root canal sealer to enhance biomineralization of dentinal tubules under controlled environment. SCANNING 38:50-56, 2016. © 2015 The Authors. Scanning Published by Wiley Periodicals, Inc. PMID:26179659

  7. Morphological aspects and physical properties of enamel and dentine of Sus domesticus: A tooth model in laboratory research.

    PubMed

    Fagundes, Nathalia Carolina Fernandes; Cardoso, Miquéias André Gomes; Miranda, Mayara Sabrina Luz; Silva, Raira de Brito; Teixeira, Francisco Bruno; Nogueira, Bárbara Catarina Lima; Nogueira, Brenna Magdalena Lima; de Melo, Sara Elisama Silva; da Costa, Natacha Malu Miranda; Lima, Rafael Rodrigues

    2015-11-01

    This study aims to describe and analyze morphological and physical properties of deciduous teeth of Sus domesticus. Ultrastructural analysis, mineral composition and microhardness of enamel and dentine tissues were performed on 10 skulls of S. domesticus. External anatomic characteristics and the internal anatomy of the teeth were also described. Data regarding microhardness and ultrastructural analysis were subjected to statistical tests. For ultrastructural analysis, we used the analysis of variance (ANOVA) with Tukey's post hoc (p≤0.05) test. In the analysis of microhardness, the difference between the enamel and dentine tissues was analyzed by a Student's t test. Values were expressed as mean with standard error. The results of ultrastructural analysis showed the presence of an enamel prism pattern. A dentinal tubule pattern was also observed, with a larger diameter in the pulp chamber and the cervical third, in comparison to middle and apical thirds. We observed an average microhardness of 259.2kgf/mm(2) for enamel and 55.17kgf/mm(2) for dentine. In porcine enamel and dentine, the chemical elements Ca and P showed the highest concentration. The analysis of internal anatomy revealed the presence of a simple root canal system and the occurrence of main canals in the roots. The observed features are compatible with the functional demand of these animals, following a pattern very similar to that seen in other groups of mammals, which can encourage the development of research using dental elements from the pig as a substitute for human teeth in laboratory research. PMID:26434756

  8. Effect of 16% Carbamide Peroxide Bleaching Gel on Enamel and Dentin Surface Micromorphology and Roughness of Uremic Patients: An Atomic Force Microscopic Study

    PubMed Central

    Mahmoud, Salah Hasab; Elembaby, Abeer El Sayed; Zaher, Ahmed Ragheb; Grawish, Mohammed El-Awady; Elsabaa, Heba M; El-Negoly, Salwa Abd El-Raof; Sobh, Mohamed Abdel Kader

    2010-01-01

    Objectives: To investigate the effect of 16% carbamide peroxide bleaching gel on surface micromorphology and roughness of enamel and root dentin of uremic patients receiving hemodialysis using atomic force microscopy (AFM). Methods: A total of 20 sound molars were collected from healthy individuals (n=10) and uremic patients (n=10). The roots were separated from their crowns at the cemento-enamel junction. Dental slabs (3 mm x 2 mm x 2 mm) were obtained from the buccal surface for enamel slabs and the cervical third of the root surface for dentin slabs. Dental slabs were then flattened and serially polished up to #2500-grit roughness using silicon carbide abrasive papers. Half of the slabs obtained from healthy individuals and uremic patients were stored in artificial saliva and left without bleaching for control and comparison. The remaining half was subjected to a bleaching treatment using 16% carbamide peroxide gel (Polanight, SDI Limited) 8 h/day for 14 days and stored in artificial saliva until AFM analysis was performed. Statistical analysis of the roughness average (Ra) results was performed using one-way ANOVA and Bonferroni post hoc multiple comparisons test. Results: The micromorphological observation of bleached, healthy enamel showed exaggerated prism irregularities more than non-bleached specimens, and this observation was less pronounced in bleached uremic enamel specimens with the lowest Ra. Bleached healthy dentin specimens showed protruded peritubular dentin and eroded intertubular dentin with the highest Ra compared to bleached uremic dentin. Conclusions: The negative effects of the bleaching gel on uremic tooth substrates are less dramatic and non-destructive compared to healthy substrates because uremia confers different micromorphological surface changes. PMID:20396450

  9. Thermal alteration and morphological changes of sound and demineralized primary dentin after Er:YAG laser ablation.

    PubMed

    Brandão, Cristina Bueno; Contente, Marta Maria Martins Giamatei; De Lima, Fabrício Augusto; Galo, Rodrigo; Corrêa-Afonso, Alessandra Marques; Bachmann, Luciano; Borsatto, Maria Cristina

    2012-02-01

    The purpose of this study was to assess the influence of Er:YAG laser pulse repetition rate on the thermal alterations occurring during laser ablation of sound and demineralized primary dentin. The morphological changes at the lased areas were examined by scanning electronic microscopy (SEM). To this end, 60 fragments of 30 sound primary molars were selected and randomly assigned to two groups (n = 30); namely A sound dentin (control) and B demineralized dentin. Each group was divided into three subgroups (n = 10) according to the employed laser frequencies: I-4 Hz; II-6 Hz, and III-10 Hz. Specimens in group B were submitted to a pH-cycling regimen for 21 consecutive days. The irradiation was performed with a 250 mJ pulse energy in the noncontact and focused mode, in the presence of a fine water mist at 1.5 mL/min, for 15 s. The measured temperature was recorded by type K thermocouples adapted to the dentin wall relative to the pulp chamber. Three samples of each group were analyzed by SEM. The data were submitted to the nonparametric Kruskal-Wallis test and to qualitative SEM analysis. The results revealed that the temperature increase did not promote any damage to the dental structure. Data analysis demonstrated that in group A, there was a statistically significant difference among all the subgroups and the temperature rise was directly proportional to the increase in frequency. In group B, there was no difference between subgroup I and II in terms of temperature. The superficial dentin observed by SEM displayed irregularities that augmented with rising frequency, both in sound and demineralized tissues. In conclusion, temperature rise and morphological alterations are directly related to frequency increment in both demineralized and sound dentin. PMID:21761493

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

    NASA Astrophysics Data System (ADS)

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

    1997-12-01

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

  11. The distinct distributions of immunocompetent cells in rat dentin pulp after pulpotomy.

    PubMed

    Zhang, Min; Kokabu, Shoichiro; Nakatomi, Chihiro; Sugiyama, Goro; Matsuo, Kou; Jimi, Eijiro

    2015-04-01

    Pulpotomy involves the removal of the coronal portion of pulp, including the diseased tissue, with the intent of maintaining the vitality of the remaining pulpal tissue via a therapeutic dressing. Once odontoblasts suffer injuries, the differentiation of mesenchymal cells is induced from the precursor cell population in the dental pulp, and these cells are recruited to the injured site to differentiate into odontoblasts. However, the involvement of immunocompetent cells during pulpal regeneration remains unclear. Thus, the purpose of this study was to investigate the properties of macrophages that infiltrated wound healing sites in rats between 1 and 28 days after pulpotomy (dap). During the inflammatory phase, ED1(+) (CD68(+) ) macrophages significantly increased throughout root pulp, especially apical to the demarcation zone, and this population persisted until 3 dap before decreasing gradually until 28 dap. OX6(+) macrophages expressing class II MHC also increased in the apical pulp at 1 dap and declined thereafter. However, OX6(+) cells appeared prior to dentin bridge formation at 3 dap and appeared again apical to the dentin bridge during the healing stage at 14 dap. The shift from ED1(+) cells in the inflammation phase to OX6(+) cells during dentin bridge formation might contribute to wound healing. PMID:25371095

  12. MEPE Localization in the Craniofacial Complex and Function in Tooth Dentin Formation.

    PubMed

    Gullard, Angela; Gluhak-Heinrich, Jelica; Papagerakis, Silvana; Sohn, Philip; Unterbrink, Aaron; Chen, Shuo; MacDougall, Mary

    2016-04-01

    Matrix extracellular phosphoglycoprotein (MEPE) is an extracellular matrix protein found in dental and skeletal tissues. Although information regarding the role of MEPE in bone and disorders of phosphate metabolism is emerging, the role of MEPE in dental tissues remains unclear. We performed RNA in situ hybridization and immunohistochemistry analyses to delineate the expression pattern of MEPE during embryonic and postnatal development in craniofacial mineralizing tissues.MepeRNA expression was seen within teeth from cap through root formation in association with odontoblasts and cellular cementoblasts. More intense expression was seen in the alveolar bone within the osteoblasts and osteocytes. MEPE immunohistochemistry showed biphasic dentin staining in incisors and more intense staining in alveolar bone matrix and in forming cartilage. Analysis ofMepenull mouse molars showed overall mineralized tooth volume and density of enamel and dentin comparable with that of wild-type samples. However,Mepe(-/-)molars exhibited increased thickness of predentin, dentin, and enamel over controls and decreased gene expression ofEnam,Bsp,Dmp1,Dspp, andOpnby RT-PCR. In vitroMepeoverexpression in odontoblasts led to significant reductions inDsppreporter activity. These data suggest MEPE may be instrumental in craniofacial and dental matrix maturation, potentially functioning in the maintenance of non-mineralized matrix. PMID:26927967

  13. Efficacy of LED versus KTP laser activation of photodynamic bleaching of tetracycline-stained dentine.

    PubMed

    Bennett, Zackary Y; Walsh, Laurence J

    2015-09-01

    In some well-established laser applications where large spot sizes are used, an array of high-intensity light emitting diodes (LED) emitting at similar wavelength could potentially replace the laser. This situation applies for the photodynamic bleaching of stains in teeth. This study compared the relative efficacy of an array of visible green LED (535 nm ± 15 nm) with a KTP laser in photodynamic bleaching of tetracycline-stained dentine in human tooth roots. After establishing consistent staining in 96 roots using a validated method, the roots were sectioned into 2-3-mm thick horizontal slices that were treated with gels containing rhodamine B (Smartbleach® or Smartbleach® 3LT). Colour changes were tracked up to 1 month after treatment. While both systems were effective in bleaching the tetracycline-stained dentine, KTP laser activation gave greater bleaching efficacy than LED activation, enhancing the action of the gel. Use of the KTP laser would be preferable over an LED system when confronted with tetracycline staining. Use of this photodynamic bleaching method offers valuable means to reduce the severity of tetracycline staining. PMID:25288264

  14. Tissue dissolution and modifications in dentin composition by different sodium hypochlorite concentrations

    PubMed Central

    TARTARI, Talita; BACHMANN, Luciano; MALIZA, Amanda Garcia Alves; ANDRADE, Flaviana Bombarda; DUARTE, Marco Antonio Hungaro; BRAMANTE, Clovis Monteiro

    2016-01-01

    ABSTRACT Sodium hypochlorite (NaOCl) remains the most used irrigation solution during root canal preparation because of characteristics such as wide-spectrum antimicrobial activity and organic tissue dissolution capacity. However, these solutions can alter dentin composition and there is no consensus on the optimal concentration of NaOCl to be used. Objectives To determine the organic matter dissolution and changes in dentin chemical composition promoted by different concentrations of NaOCl over time. Material and Methods: Fragments of bovine muscle tissue were weighed before and after 5, 10, and 15 min of immersion in the groups (n=10): G1- 0.9% saline solution; G2- 1% NaOCl; G3- 2.5% NaOCl; and G4- 5% NaOCl. Bovine dentin fragments were subjected to the same irrigants and absorption spectra were collected by Attenuated Total Reflectance of Fourier Transform Infrared Spectroscopy (ATR-FTIR) before and after 0,5, 1, 2, 3, 5, 8, and 10 min of immersion in the solutions. The ratios of the amide III/phosphate and carbonate/phosphate absorption bands were determined. The tissue dissolution and carbonate/phosphate ratios were submitted to the two-way analysis of variance (ANOVA) with Tukey’s multiple-comparison test (α<0.05) and to the one-way analysis of variance with Tukey’s (α<0.05). The amide III/phosphate ratio was analyzed by Friedman test (α<0.05) and the Kruskal-Wallis test with Dunn’s post-hoc (α<0.05). Results The increase in NaOCl concentration and contact time intensified the dissolution of organic matter and dentin collagen with reduction in the amide III/phosphate ratio. Significant differences between all groups (p<0.05) were observed in the dissolution of organic matter at 10 min and in the amide III/phosphate ratio between the saline solution and 5% NaOCl at 5 min. The carbonate/phosphate ratio decreased significantly in G2, G3, and G4 after 0,5 min of immersion (p<0.05), but more alterations did not occur in the subsequent periods (p>0

  15. Effect of dentin location and long-term water storage on bonding effectiveness of dentin adhesives.

    PubMed

    De Munck, Jan; Mine, Atsushi; Vivan Cardoso, Marcio; De Almeida Neves, Aline; Van Landuyt, Kirsten L; Poitevin, André; Van Meerbeek, Bart

    2011-01-01

    Dentin is a variable substrate with properties that change considerable in a single surface. The purpose of this study was to evaluate the bonding effectiveness to these different dentin locations and evaluate these differences over time. After bonding procedures with five different adhesives, small micro-tensile bond strength (µTBS) beams were prepared and dichotomously divided in 'center' and 'periphery' dentin specimens. After 1 week, 3, 6 and 12 months of water storage the µTBS of specimens of each group was determined, enabling a paired study design. The bond strengths of both etch&rinse adhesives were insensitive to regional variability. For the two-step self-etch adhesives, a marked increase in bond strengths was observed with increasing amount of intertubular dentin. Regional variability did not affect the long-term bonding effectiveness for any of the adhesives tested. In conclusion, only for the mild self-etch adhesives, µTBS to 'periphery' dentin was higher than for the 'center' specimens. PMID:21282894

  16. Grape seed extracts inhibit dentin matrix degradation by MMP-3

    PubMed Central

    Khaddam, Mayssam; Salmon, Benjamin; Le Denmat, Dominique; Tjaderhane, Leo; Menashi, Suzanne; Chaussain, Catherine; Rochefort, Gaël Y.; Boukpessi, Tchilalo

    2014-01-01

    Since Matrix metalloproteinases (MMPs) have been suggested to contribute to dentin caries progression, the hypothesis that MMP inhibition would affect the progression of dentin caries is clinically relevant. Grape seed extracts (GSE) have been previously reported to be natural inhibitors of MMPs. Objective: To evaluate the capacity of a GSE mouthrinse to prevent the degradation of demineralized dentin matrix by MMP-3 (stromelysin-1). Materials and Methods: Standardized blocks of dentin obtained from sound permanent teeth extracted for orthodontic reasons were demineralized with Ethylenediaminetetraacetic acid (EDTA) and pretreated either with (A) GSE (0.2% w/v), (B) amine fluoride (AmF) (20% w/v), (C) a mouthrinse which contains both, (D) placebo, (E) sodium fluoride (0.15 mg.ml−1), (F) PBS, (G) Chlorhexidine digluconate (CHX), or (H) zinc chloride (ZnCl2). The dentin blocks were then incubated with activated recombinant MMP-3. The supernatants were analyzed by Western Blot for several dentin matrix proteins known to be MMP-3 substrate. In parallel, scanning electron microscopy (SEM) was performed on resin replica of the dentin blocks. Results: Western blot analysis of the supernatants revealed that MMP-3 released from the dentin matrix small proteoglycans (decorin and biglycan) and dentin sialoprotein (DSP) in the AmF, sodium fluoride, PBS and placebo pretreated groups, but not in the GSE and mouthrinse pretreated groups. SEM examination of resin replica showed that the mouthrinse and its active components not only had an anti-MMP action but also modified the dentin surface accessibility. Conclusion: This study shows that GSE either alone or combined with AmF as in the evaluated mouthrinse limits dentin matrix degradation. This association may be promising to prevent the progression of caries within dentin. However, the procedure should be adapted to clinically relevant durations. PMID:25400590

  17. The effect of rotary instrumentation on the permeability of dentin

    SciTech Connect

    Boyer, D.B.; Svare, C.W.

    1981-06-01

    The filtration and diffusion of tritiated water through dentin disks were measured ina split-chamber diffusion cell. The dentin had been cut with a diamond disk and the surfaces modified with a carbide fissure bur or diamond bur. Disks were given a secondary burnishing treatment with a blank bur or a modified blank bur. Burnishing reduced the permeability of dentin cut with a fissure bur.

  18. SEM evaluation of nanoparticulate silver penetration into dentine collagen matrix

    NASA Astrophysics Data System (ADS)

    Bessudnova, Nadezda O.; Bilenko, David I.; Venig, Sergey B.

    2014-01-01

    In the present study a novel approach to caries management based on the application of nanoparticles of different nature to increase the mineral phase of demineralized dentin has been developed. Silver nanoparticles have been tested as a material for dentine matrix infiltration. Research findings clearly show that collagen fibers of demineralized dentine could be considered as a scaffold for mineral component delivery and the place where mineral growth can occur.

  19. Preventive effect of toothpastes with MMP inhibitors on human dentine erosion and abrasion in vitro

    PubMed Central

    Hannas, Angelica Reis; Kato, Melissa Thiemi; Cardoso, Cristiane de Almeida Baldini; Magalhães, Ana Carolina; Pereira, José Carlos; Tjäderhane, Leo; Buzalaf, Marília Afonso Rabelo

    2016-01-01

    ABSTRACT The use of gels and mouthrinses with MMP inhibitors (chlorhexidine, and green tea extract) was shown to prevent erosive wear. The aim of this study was to analyze the protective effect of toothpastes containing MMP inhibitors on dentine loss induced by erosion in vitro. Material and Methods Five groups each containing 12 specimens of human root dentine were prepared. The specimens were subjected to 1 min erosion by immersion in a cola drink, 4 times a day, for 5 d. Each day, after the first and last erosive challenges, the specimens were brushed for 15 s with a slurry of dentifrice and water (1:3) containing placebo, 1,100 ppm fluoride, 0.61% green tea extract, 0.12% chlorhexidine or 0.004% chlorhexidine (commercial toothpaste). Between the acid challenges, the specimens were stored in artificial saliva with remineralizing potential until the next treatment. Dentine loss was determined using profilometry. Data were analyzed using one-way ANOVA after log transform (p<0.05). Results The mean wear values (μm) were as follows: placebo 1.83±0.53; 0.61% green tea extract 1.00±0.21; fluoride 1.27±0.43; 0.12% chlorhexidine 1.19±0.30; and 0.004% chlorhexidine 1.22±0.46. There was a significant difference in wear between placebo and all the treatment toothpastes, which did not differ from each other. Conclusion The results suggest that toothpastes containing MMP inhibitors are as effective as those based on NaF in preventing dentine erosion and abrasion. PMID:27008258

  20. Preventive effect of toothpastes with MMP inhibitors on human dentine erosion and abrasion in vitro.

    PubMed

    Hannas, Angelica Reis; Kato, Melissa Thiemi; Cardoso, Cristiane de Almeida Baldini; Magalhães, Ana Carolina; Pereira, José Carlos; Tjäderhane, Leo; Buzalaf, Marília Afonso Rabelo

    2016-02-01

    The use of gels and mouthrinses with MMP inhibitors (chlorhexidine, and green tea extract) was shown to prevent erosive wear. The aim of this study was to analyze the protective effect of toothpastes containing MMP inhibitors on dentine loss induced by erosion in vitro. Material and Methods Five groups each containing 12 specimens of human root dentine were prepared. The specimens were subjected to 1 min erosion by immersion in a cola drink, 4 times a day, for 5 d. Each day, after the first and last erosive challenges, the specimens were brushed for 15 s with a slurry of dentifrice and water (1:3) containing placebo, 1,100 ppm fluoride, 0.61% green tea extract, 0.12% chlorhexidine or 0.004% chlorhexidine (commercial toothpaste). Between the acid challenges, the specimens were stored in artificial saliva with remineralizing potential until the next treatment. Dentine loss was determined using profilometry. Data were analyzed using one-way ANOVA after log transform (p<0.05). Results The mean wear values (μm) were as follows: placebo 1.83±0.53; 0.61% green tea extract 1.00±0.21; fluoride 1.27±0.43; 0.12% chlorhexidine 1.19±0.30; and 0.004% chlorhexidine 1.22±0.46. There was a significant difference in wear between placebo and all the treatment toothpastes, which did not differ from each other. Conclusion The results suggest that toothpastes containing MMP inhibitors are as effective as those based on NaF in preventing dentine erosion and abrasion. PMID:27008258

  1. Evaluation of mineral content of dentin treated with desensitizing agents and neodymium yttrium-aluminium-garnet (Nd:YAG) laser.

    PubMed

    Malkoç, Meral Arslan; Sevimay, Müjde

    2012-07-01

    The aim of this study was to evaluate the mineral content of dentin prepared using three different desensitizing agents and the Nd:YAG laser. The occlusal third of the crowns of 30 molar teeth were cut with a slow-speed diamond saw sectioning machine under water cooling. Dentin slabs from the 30 teeth were randomly divided into five experimental groups, each comprising six slabs. The five groups were treated as follows: group A, no treatment; group B, treatment with oxalate-containing desensitizing agent (BisBlock); group C, treatment with resin-based desensitizing agent (Admira Protect); group D, treatment with glutaraldehyde-containing desensitizing agent (Systemp); and group E, irradiation with the Nd:YAG laser (DEKATM ) at 0.40 W. The levels of Mg, P, Ca, K, and Na in each slab were measured by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Data were analyzed by one-way analysis of variance and the Tukey HSD test. The effect of desensitizing agents and laser irradiation on the dentin surface were evaluated using a scanning electron microscope. There were no significant differences between the groups (p > 0.05). Group E was showed the lowest Ca/P ratio. SEM showed that the resin-based agent occluded the dentinal tubules, the glutaraldehyde-containing agent increased the Ca/P ratio, and Nd:YAG laser irradiation decreased the Ca/P ratio. The mean percentages by weight of Ca, Mg, K, Na and P were not affected by Nd:YAG laser irradiation or any of the desensitizing agents. PMID:21789631

  2. Hierarchical structure and mechanical properties of remineralized dentin.

    PubMed

    Chen, Yi; Wang, Jianming; Sun, Jian; Mao, Caiyun; Wang, Wei; Pan, Haihua; Tang, Ruikang; Gu, Xinhua

    2014-12-01

    It is widely accepted that the mechanical properties of dentin are significantly determined by its hierarchical structure. The current correlation between the mechanical properties and the hierarchical structure was mainly established by studying altered forms of dentin, which limits the potential outcome of the research. In this study, dentins with three different hierarchical structures were obtained via two different remineralization procedures and at different remineralization stages: (1) a dentin structure with amorphous minerals incorporated into the collagen fibrils, (2) a dentin with crystallized nanominerals incorporated into the collagen fibrils, and (3) a dentin with an out-of-order mineral layer filling the collagen fibrils matrix. Nanoindentation tests were performed to investigate the mechanical behavior of the remineralized dentin slides. The results showed that the incorporation of the crystallized nanominerals into the acid-etched demineralized organic fibrils resulted in a remarkable improvement of the mechanical properties of the dentin. In contrast, for the other two structures, i.e. the amorphous minerals inside the collagen fibrils and the out-of-order mineral layer within the collagen fibrils matrix, the excellent mechanical properties of dentin could not be restored. PMID:25259668

  3. Photosensitizer and light diffusion through dentin in photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Nogueira, Ana C.; Graciano, Ariane X.; Nagata, Juliana Y.; Fujimaki, Mitsue; Terada, Raquel S. S.; Bento, Antonio C.; Astrath, Nelson G. C.; Baesso, Mauro L.

    2013-05-01

    Photodynamic therapy has been considered a potential antimicrobial modality against oral infections, including dental caries. A model to estimate the penetration of both photosensitizers and light through human dentin, a factor of interest in photodynamic therapy, is proposed. The photoacoustic spectroscopy technique was used to evaluate in vitro dentin permeability of three different photosensitizers. Using the dentin optical absorption and scattering coefficients, it was possible to propose a semi-quantitative model predicting both photosensitizer and light doses within dentin. The graphic illustrations obtained provided guidelines that may be useful in photodynamic therapy protocols used as antimicrobial tools in caries lesions.

  4. Efficacy of a root conditioning agent on fibrin network formation in periodontal regeneration: A SEM evaluation

    PubMed Central

    Amireddy, Rajender; Rangarao, Suresh; lavu, Vamsi; Madapusi, Balaji Todur

    2011-01-01

    Background: Even though numerous biomaterials have been devised and employed for periodontal regeneration, it should be well understood that the root surface receptiveness to clot formation and maintenance during initial periodontal wound healing, decides the nature of the connective tissue attachment. So this study was carried out with the prime objective of assessing the initial wound healing events occurring in vivo after the application of citric acid on to the root surfaces during periodontal regenerative therapy. Materials and Methods: Thirty-two human teeth were used for this in vitro study. Two dentin blocks each measuring 4 × 2 × 1 mm were made from each tooth. These dentin blocks were planed and treated differently with Phosphate Buffered Saline (PBS), citric acid, PBS and fresh human blood, citric acid and fresh human blood and were segregated into eight groups. Finally all the dentin blocks were processed and subjected to a scanning electron microscope study. Results: In PBS-treated samples, the dentin surface was irregular corresponding to smear layer and the dentinal tubule openings were obscured. Whereas, in those treated with citric acid revealed a smooth dentin surface devoid of smear layer and the dentinal tubular openings were clear. Further samples that were treated with PBS plus blood showed little or no fibrin network formation whereas with those citric acid plus blood showed a fine thick fibrin network formation adhered to dentinal surface. Conclusion: The results of this present in vitro study suggests that use of citric acid as a root conditioning agent has a beneficial effect on initial wound healing events, which are critical for periodontal regenerative therapies. PMID:22028509

  5. Efficient Rutin and Quercetin Biosynthesis through Flavonoids-Related Gene Expression in Fagopyrum tataricum Gaertn. Hairy Root Cultures with UV-B Irradiation

    PubMed Central

    Huang, Xuan; Yao, Jingwen; Zhao, Yangyang; Xie, Dengfeng; Jiang, Xue; Xu, Ziqin

    2016-01-01

    Transformed hairy roots had been efficiently induced from the seedlings of Fagopyrum tataricum Gaertn. due to the infection of Agrobacterium rhizogenes. Hairy roots were able to display active elongation with high root branching in 1/2 MS medium without growth regulators. The stable introduction of rolB and aux1 genes of A. rhizogenes WT strain 15834 into F. tataricum plants was confirmed by PCR analysis. Besides, the absence of virD gene confirmed hairy root was bacteria-free. After six different media and different sources of concentration were tested, the culturing of TB7 hairy root line in 1/2 MS liquid medium supplemented with 30 g l-1 sucrose for 20 days resulted in a maximal biomass accumulation (13.5 g l-1 fresh weight, 1.78 g l-1 dry weight) and rutin content (0.85 mg g-1). The suspension culture of hairy roots led to a 45-fold biomass increase and a 4.11-fold rutin content increase in comparison with the suspension culture of non-transformed roots. The transformation frequency was enhanced through preculturing for 2 days followed by infection for 20 min. The UV-B stress treatment of hairy roots resulted in a striking increase of rutin and quercetin production. Furthermore, the hairy root lines of TB3, TB7, and TB28 were chosen to study the specific effects of UV-B on flavonoid accumulation and flavonoid biosynthetic gene expression by qRT-PCR. This study has demonstrated that the UV-B radiation was an effective elicitor that dramatically changed in the transcript abundance of ftpAL, FtCHI, FtCHS, FtF3H, and FtFLS-1 in F. tataricum hairy roots. PMID:26870075

  6. Efficient Rutin and Quercetin Biosynthesis through Flavonoids-Related Gene Expression in Fagopyrum tataricum Gaertn. Hairy Root Cultures with UV-B Irradiation.

    PubMed

    Huang, Xuan; Yao, Jingwen; Zhao, Yangyang; Xie, Dengfeng; Jiang, Xue; Xu, Ziqin

    2016-01-01

    Transformed hairy roots had been efficiently induced from the seedlings of Fagopyrum tataricum Gaertn. due to the infection of Agrobacterium rhizogenes. Hairy roots were able to display active elongation with high root branching in 1/2 MS medium without growth regulators. The stable introduction of rolB and aux1 genes of A. rhizogenes WT strain 15834 into F. tataricum plants was confirmed by PCR analysis. Besides, the absence of virD gene confirmed hairy root was bacteria-free. After six different media and different sources of concentration were tested, the culturing of TB7 hairy root line in 1/2 MS liquid medium supplemented with 30 g l(-1) sucrose for 20 days resulted in a maximal biomass accumulation (13.5 g l(-1) fresh weight, 1.78 g l(-1) dry weight) and rutin content (0.85 mg g(-1)). The suspension culture of hairy roots led to a 45-fold biomass increase and a 4.11-fold rutin content increase in comparison with the suspension culture of non-transformed roots. The transformation frequency was enhanced through preculturing for 2 days followed by infection for 20 min. The UV-B stress treatment of hairy roots resulted in a striking increase of rutin and quercetin production. Furthermore, the hairy root lines of TB3, TB7, and TB28 were chosen to study the specific effects of UV-B on flavonoid accumulation and flavonoid biosynthetic gene expression by qRT-PCR. This study has demonstrated that the UV-B radiation was an effective elicitor that dramatically changed in the transcript abundance of ftpAL, FtCHI, FtCHS, FtF3H, and FtFLS-1 in F. tataricum hairy roots. PMID:26870075

  7. Roots Revisited.

    ERIC Educational Resources Information Center

    Hughes, Barnabas

    1998-01-01

    Offers historical information about square roots. Presents three different methods--Hero's method, visual method, and remainder method--which can be used to teach the finding of square roots and one method for determining cube roots. (ASK)

  8. A Mechanistic study of Plasma Treatment Effects on Demineralized Dentin Surfaces for Improved Adhesive/Dentin Interface Bonding

    PubMed Central

    Dong, Xiaoqing; Chen, Meng; Wang, Yong; Yu, Qingsong

    2014-01-01

    Our previous work has shown that non-thermal plasma treatment of demineralized dentin significantly (p<0.05) improved adhesive/dentin bonding strength for dental composite restoration as compared with the untreated controls. This study is to achieve mechanistic understanding of the plasma treatment effects on dentin surface through investigating the plasma treated dentin surfaces and their interaction with adhesive monomer, 2-Hydroxyethyl methacrylate (HEMA). The plasma treated dentin surfaces from human third molars were evaluated by water contact angle measurements and scanning electron microscopy (SEM). It was found that plasma-treated dentin surface with subsequent HEMA immersion (Plasma/HEMA Treated) had much lower water contact angle compared with only plasma-treated (Plasma Treated) or only HEMA immersed (HEMA Treated) dentin surfaces. With prolong water droplet deposition time, water droplets spread out completely on the Plasma/HEMA Treated dentin surfaces. SEM images of Plasma/HEMA Treated dentin surfaces verified that dentin tubules were opened-up and filled with HEMA monomers. Extracted type I collagen fibrils, which was used as simulation of the exposed dentinal collagen fibrils after acid etching step, were plasma treated and analyzed with Fourier transform infrared spectroscopy (FT-IR) and circular dichroism (CD) spectra. FT-IR spectra of the Plasma/HEMA Treated collage fibrils showed broadened amide I peak at 1660 cm−1 and amide II at 1550 cm−1, which indicate secondary structure changes of the collagen fibrils. CD spectra indicated that 67.4% collagen helix structures were denatured after plasma treatment. These experimental results demonstrate that non-thermal argon plasma treatment was very effective in loosing collagen structure and enhancing adhesive monomer penetration, which are beneficial to thicker hybrid layer and longer resin tag formation, and consequently enhance adhesive/dentin interface bonding. PMID:25267936

  9. Caries-resistant bonding layer in dentin

    PubMed Central

    Zhou, Wei; Niu, Li-na; Hu, Lin; Jiao, Kai; Chang, Gang; Shen, Li-juan; Tay, Franklin R.; Chen, Ji-hua

    2016-01-01

    The present study examined the mechanism for caries resistance and the pulp responses in vital teeth following the use of the augmented-pressure adhesive displacement technique. Dentin adhesives were applied to the surface of sound dentin disks in 4 experimental groups: non-antibacterial adhesive and gentle adhesive displacement (N-G), non-antibacterial adhesive and augmented-pressure adhesive displacement (N-H), antibacterial adhesive and gentle adhesive displacement (A-G), antibacterial adhesive and augmented-pressure adhesive displacement (A-H). The depth of demineralization induced by biological or chemical demineralization models was measured using confocal laser scanning microscopy and analyzed with two-way ANOVA. Pulp responses of vital dog’s teeth to the augmented-pressure adhesive displacement technique were evaluated using light microscopy. Depth of demineralization was significantly affected by “adhesive type” and “intensity of adhesive displacement” for biological demineralization. For chemical demineralization, only “intensity of adhesive displacement” showed significant influence on lesion depth. Pulp response of 0.1, 0.2 and 0.3 MPa groups showed only moderate disorganization of the odontoblast layer at 24 hours that completely re-organized after 3 weeks. Augmented-pressure adhesive displacement improves the caries resistance property of bonded dentin and does not cause irreversible pulpal damage to vital teeth when the air pressure employed is equal or smaller than 0.3 MPa. PMID:27599621

  10. Clinical effectiveness of contemporary dentin bonding agents

    PubMed Central

    Krithikadatta, Jogikalmat

    2010-01-01

    Aim: The purpose of this paper is to review the literature on the clinical effectiveness of contemporary resin-based dentin bonding agents primarily focussing on the longevity of restoration. Materials and Methods: The literature published from June 2004 up to September 2010 was reviewed for clinical trials that tested the effectiveness of dentin bonding agents in the longevity of noncarious class V restoration. Results of each study reported using the USPHS criteria for clinical assessment of restoration were included and tabulated. The American Dental Association guidelines for dentin and enamel adhesives were used as a reference to compare the performance of individual bonding agents. Kruskal–Wallis followed by Mann–Whitney U was done to compare the mean Alfa score percentage for the three categories of bonding systems [etch-and-rinse (ER), self-etch primer (SEP), and self-etch-adhesive (SEA)]. Results: A comparison of the mean Alfa score percentages revealed no difference between the ER, SEP, and SEA categories of bonding systems except for marginal adaptation where ER was found to be superior to SEA. Conclusion: The clinical effectiveness of resin-based bonding agents is comparable among the three categories. PMID:21217944

  11. Diagnosis and treatment of dentinal hypersensitivity.

    PubMed

    Porto, Isabel C C M; Andrade, Ana K M; Montes, Marcos A J R

    2009-09-01

    This bibliographic review provides a general view of the etiology, characteristics and treatment of dentinal hypersensitivity, so that professionals can use this information in the therapeutic management of this clinical condition. For this purpose, the authors have analyzed whole texts of relevant articles on the subject. This study showed that the predisposing factors associated with the causes of dentinal hypersensitivity must be controlled or eliminated, by educating the patient regarding the excessive intake of acidic food, as well as providing guidance on the proper tooth brushing technique and analysis of occlusion. Effective treatment must be preceded by a proper diagnosis, established after the exclusion of any other possible causes of the pain. These cases must be managed efficiently, quickly and permanently. The availability of a wide variety of treatment could be an indicator that there is still no effective desensitizing agent to completely resolve the patient's discomfort, or that it is difficult to treat, irrespective of the available treatment options. Even with the large number of published studies, it has not been possible to reach a consensus about the product that represents the gold standard in the treatment of dentinal hypersensitivity. PMID:19776498

  12. Dentin hypersensitivity: Recent trends in management

    PubMed Central

    Miglani, Sanjay; Aggarwal, Vivek; Ahuja, Bhoomika

    2010-01-01

    Dentinal hypersensitivity (DH) is a common clinical condition usually associated with exposed dentinal surfaces. It can affect patients of any age group and most commonly affects the canines and premolars of both the arches. This article concisely reviews the patho-physiology, mechanism and clinical management of the DH. Treatment of DH should start with an accurate diagnosis. Differential diagnosis should be made and all other probable causes should be excluded. An often neglected phase of clinical management of DH is the identification and treatment of the causative factors of DH. By removing the etiological factors, the condition can be even prevented from occurring or recurring. There are various treatment modalities available which can be used at home or may be professionally applied. The “at home” desensitizing agents include toothpastes, mouthwashes or chewing gums and they act by either occluding the dentinal tubules or blocking the neural transmission. This article also discusses the recent treatment options like bioglass, Portland cement, lasers and casein phosphopeptide. PMID:21217949

  13. Caries-resistant bonding layer in dentin.

    PubMed

    Zhou, Wei; Niu, Li-Na; Hu, Lin; Jiao, Kai; Chang, Gang; Shen, Li-Juan; Tay, Franklin R; Chen, Ji-Hua

    2016-01-01

    The present study examined the mechanism for caries resistance and the pulp responses in vital teeth following the use of the augmented-pressure adhesive displacement technique. Dentin adhesives were applied to the surface of sound dentin disks in 4 experimental groups: non-antibacterial adhesive and gentle adhesive displacement (N-G), non-antibacterial adhesive and augmented-pressure adhesive displacement (N-H), antibacterial adhesive and gentle adhesive displacement (A-G), antibacterial adhesive and augmented-pressure adhesive displacement (A-H). The depth of demineralization induced by biological or chemical demineralization models was measured using confocal laser scanning microscopy and analyzed with two-way ANOVA. Pulp responses of vital dog's teeth to the augmented-pressure adhesive displacement technique were evaluated using light microscopy. Depth of demineralization was significantly affected by "adhesive type" and "intensity of adhesive displacement" for biological demineralization. For chemical demineralization, only "intensity of adhesive displacement" showed significant influence on lesion depth. Pulp response of 0.1, 0.2 and 0.3 MPa groups showed only moderate disorganization of the odontoblast layer at 24 hours that completely re-organized after 3 weeks. Augmented-pressure adhesive displacement improves the caries resistance property of bonded dentin and does not cause irreversible pulpal damage to vital teeth when the air pressure employed is equal or smaller than 0.3 MPa. PMID:27599621

  14. Phenotypic heterogeneity of Streptococcus mutans in dentin.

    PubMed

    Rupf, S; Hannig, M; Breitung, K; Schellenberger, W; Eschrich, K; Remmerbach, T; Kneist, S

    2008-12-01

    Information concerning phenotypic heterogeneity of Streptococcus mutans in carious dentin is sparse. Matrix-assisted laser-desorption/ionization-time-of-flight mass-spectrometry (MALDI-TOF-MS) facilitates the phenotypic differentiation of bacteria to the subspecies level. To verify a supposed influence of restorative treatment on the phenotypic heterogeneity of S. mutans, we isolated and compared a total of 222 S. mutans strains from dentin samples of 21 human deciduous molars during caries excavation (T(1)) and 8 wks (T(2)) after removal of the temporary restoration. Phenotypic heterogeneity was determined by MALDI-TOF-MS and hierarchical clustering. Thirty-six distinct S. mutans phenotypes could be identified. Although indistinguishable phenotypes were found in the same teeth at T(1) and T(2), as well as in different teeth of individual participants, the phenotypic heterogeneity increased significantly, from 1.4 phenotypes per S. mutans-positive dentin sample at T(1) to 2.2 phenotypes at T(2). We attribute this to an adaptation of S. mutans to the modified environment under the restoration following caries excavation. PMID:19029088

  15. Tensile strength and durability of bovine dentin.

    PubMed

    Inoue, Toshiko; Miyazaki, Takashi; Nishimura, Fumio

    2007-05-01

    This study investigated the effects of thermal cycling on the tensile strength of dentin. Bovine dentin were divided into 10 groups, which were then subjected to various conditions: intact after preparation, thereby serving as a control; heating in boiling water for 45 minutes; 10,000 thermal cycles in water; 10,000 thermal cycles in PBS; storage in water at 5, 23, or 55 degrees C for two weeks; and storage in PBS at 5, 23, or 55 degrees C for two weeks. Subsequently, bovine dentin were trimmed into dumbbell-shaped specimens and the tensile test performed in distilled water at 37 degrees C. Mean tensile strengths were compared statistically by one-way ANOVA and Fisher's PLTD test (p<0.05). Fracture surfaces were observed by scanning electron microscopy, and reliability of the results was analyzed with Weibull distribution. Tensile strength did not significantly change after thermal cycling or storage in water and PBS at all temperatures tested (71.2-77.0 MPa) but decreased after treatment with boiling water (65.5 MPa). PMID:17694743

  16. The surface modification of tooth dentine with a Free Electron Laser (FEL)

    NASA Astrophysics Data System (ADS)

    Ogino, Seiji; Awazu, Kunio

    1998-09-01

    Free Electron Laser (FEL) with the wide wavelength tunability has been developed and used for various applications. The FEL gives high efficiency for the photo-induced ablation when the laser is tuned to an absorption maximum of the target. The FEL was tuned to 9.4 μm, which is an absorption maximum of phosphoric acid ion, a known major component of dentine. The FEL pulse length was several ps. The average output power was varied from 5 to 20 mW by filters. The change of irradiated dentine surface was analyzed by mass spectroscopy and Energy Dispersive X-ray (EDX) spectroscopy. Positive ions which correspond to Na +, CO 3+ and many phosphoric acid ions were measured. It was found that atomic ratio of P/Ca had reduced from 0.65-0.60. The atomic ratio of P/Ca, however had not changed with irradiation by Er:YAG laser (2.9 μm), or CO 2 laser (10.6 μm). These results indicate the selective ablation of phosphoric acid ion by the 9.4 mm FEL irradiation.

  17. Remineralization of root caries monitored using cross polarization optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Darling, Cynthia L.; Staninec, Michal; Chan, Kenneth H.; Kang, Hobin; Fried, Daniel

    2012-01-01

    Previous studies have demonstrated that polarization sensitive optical coherence tomography (PS-OCT) can be used to image caries lesions in dentin, measure nondestructively the severity of dentin demineralization, and determine the efficacy of intervention with anticaries agents including fluoride and lasers. However, those studies were limited to artificial lesions on dentin and roots surfaces. The objective of this study is to determine if a cross polarization OCT system (CP-OCT) can be used to nondestructively measure a reduction in the reflectivity of natural root caries lesions after exposure to a remineralization solution. CPOCT images of 11 teeth with existing root lesions were acquired before and after exposure to a remineralizing solution for 20 days. The integrated reflectivity was calculated after integrating to a fixed depth of 200-μm. There was a significant decrease in the integrated reflectivity after exposure to the remineralizing solution.

  18. Selective treatment of carious dentin using a mid-infrared tunable pulsed laser at 6 μm wavelength range

    NASA Astrophysics Data System (ADS)

    Saiki, Masayuki; Ishii, Katsunori; Yoshikawa, Kazushi; Yasuo, Kenzo; Yamamoto, Kazuyo; Awazu, Kunio

    2011-03-01

    Optical technologies have good potential for caries detection, prevention, excavation, and the realization of minimal intervention dentistry. This study aimed to develop a selective excavation technique of carious tissue using the specific absorption in 6 μm wavelength range. Bovine dentin demineralized with lactic acid solution was used as a carious dentin model. A mid-infrared tunable pulsed laser was obtained by difference-frequency generation technique. The wavelength was tuned to 6.02 and 6.42 μm which correspond to absorption bands called amide I and amide II, respectively. The laser delivers 5 ns pulse width at a repetition rate of 10 Hz. The morphological change after irradiation was observed with a scanning electron microscope, and the measurement of ablation depth was performed with a confocal laser microscope. At λ = 6.02 μm and the average power density of 15 W/cm2, demineralized dentin was removed selectively with less-invasive effect on sound dentin. The wavelength of 6.42 μm also showed the possibility of selective removal. High ablation efficiency and low thermal side effect were observed using the nanosecond pulsed laser with λ = 6.02 μm. In the near future, development of compact laser device will open the minimal invasive laser treatment to the dental clinic.

  19. Bacterial reduction and dentin microhardness after treatment by a pulsed fiber optic delivered Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    Goodis, Harold E.; White, Joel M.; Marshall, Sally J.; Marshall, Grayson W.

    1994-09-01

    The purpose of this study was to determine the microhardness and extent of bacterial reduction of contaminated dentin following pulsed fiber optic delivered Nd:YAG laser exposure. Knoop hardness was determined before and after laser exposures from 0.3 to 3.0 W and repetition rates of 10 to 30 Hz. Half the sections were covered with an organic black pigment before laser exposure to evaluate the use of the pigment as an initiator to increase laser absorbance on the surface. Repeated measures design was employed to determine the microhardness of cut and polished dentin sections. Additional dentin sections were sterilized by gamma irradiation and then inoculated with B. subtilis, E. coli or B. stearothermophilus. The contaminated sections were exposed to contact delivered Nd:YAG laser. Cultures were obtained from the dentin surfaces and the colony forming units counted. Increased microhardness was found for all laser treatments above the physical modification. Bacterial reduction was obtained but complete sterilization was not.

  20. Holmium:YAG laser: effect on pulpal tissues and root surfaces

    NASA Astrophysics Data System (ADS)

    Holt, Raleigh A.; Nordquist, Robert E.

    1996-04-01

    The effects of the Holmium:YAG irradiation on the pulpal tissues and surface topography on root surface dentin in human teeth in vivo were studied. The exposed root surfaces of seventeen pre-immediate denture patients were scaled and root planed with a Gracey 3 - 4 curette apical to the dentinoenamel junction until smooth and hard. The prepared root surfaces of two teeth per patient were exposed with Holmium:YAG laser energy after an application of nonfilled resin/fluoride mixture. The laser exposed areas were below the dentinoenamel junction around one-half of each root surface. The opposing sides of each of the teeth received resin/fluoride but no laser energy. A third tooth was identified as a nontreated control. The HO:YAG at 2.12 microns wavelength with a defocused beam size of 3 mm was used. The amount of laser energy delivered per 3 X 5 mm area was 0.450 (+/- .05) joules with a fluence of 2.66 - 3.30 J/cm2. The teeth were extracted after periods of 45 - 120 days. The specimens were fixed in formalin and prepared for histological examination using hematoxylin and eosin stains. Microscopic evaluation of room surfaces showed increased smoothness on the laser treated sites compared to their opposing non-lased sides. Histological examination of the pulpal tissues exhibited no abnormal changes. No clinical symptoms of pulpal pathology were produced. HO:YAG laser energy proved safe for treating room surfaces of human teeth in vivo under conditions presented in this study.

  1. Coinvasion of dentinal tubules by Porphyromonas gingivalis and Streptococcus gordonii depends upon binding specificity of streptococcal antigen I/II adhesin.

    PubMed

    Love, R M; McMillan, M D; Park, Y; Jenkinson, H F

    2000-03-01

    Cell wall-anchored polypeptides of the antigen I/II family are produced by many species of oral streptococci. These proteins mediate adhesion of streptococci to salivary glycoproteins and to other oral microorganisms and promote binding of cells to collagen type I and invasion of dentinal tubules. Since infections of the root canal system have a mixed anaerobic bacterial etiology, we investigated the hypothesis that coadhesion of anaerobic bacteria with streptococci may facilitate invasive endodontic disease. Porphyromonas gingivalis ATCC 33277 cells were able to invade dentinal tubules when cocultured with Streptococcus gordonii DL1 (Challis) but not when cocultured with Streptococcus mutans NG8. An isogenic noninvasive mutant of S. gordonii, with production of SspA and SspB (antigen I/II family) polypeptides abrogated, was deficient in binding to collagen and had a 40% reduced ability to support adhesion of P. gingivalis. Heterologous expression of the S. mutans SpaP (antigen I/II) protein in this mutant restored collagen binding and tubule invasion but not adhesion to P. gingivalis or the ability to promote P. gingivalis coinvasion of dentin. An isogenic afimbrial mutant of P. gingivalis had 50% reduced binding to S. gordonii cells but was unaffected in the ability to coinvade dentinal tubules with S. gordonii wild-type cells. Expression of the S. gordonii SspA or SspB polypeptide on the surface of Lactococcus lactis cells endowed these bacteria with the abilities to bind P. gingivalis, penetrate dentinal tubules, and promote P. gingivalis coinvasion of dentin. The results demonstrate that collagen-binding and P. gingivalis-binding properties of antigen I/II polypeptides are discrete functions. Specificity of antigen I/II polypeptide recognition accounts for the ability of P. gingivalis to coinvade dentinal tubules with S. gordonii but not with S. mutans. This provides evidence that the specificity of interbacterial coadhesion may influence directly the etiology

  2. Micromorphological Evaluation of Dentin Treated with Different Desensitizing Agents

    PubMed Central

    Osmari, Deise; de Oliveira Ferreira, Ana Carolina; de Carlo Bello, Mariana; Henrique Susin, Alexandre; Cecília Correa Aranha, Ana; Marquezan, Marcela; Lopes da Silveira, Bruno

    2013-01-01

    Introduction: The purpose of a desensitizing agent is a permanent coating or filling of dentin surface. Morphological analysis in vitro of this treated surface is essential to understand the interaction between desensitizing agent and hypersensitive dentin. The aim was to evaluate the morphology of four dentin surface treated with desensitizing agents. Methods: This was an in vitro laboratory study, where fifteen specimens from extracted human premolars were obtained. The enamel was removed to expose the dentin surface, polished with silicon carbide abrasive papers and etched with 6% citric acid for 2 min.The specimens were randomly divided into 5 groups: G1 - without treatment (control) (C), G2 - fluoride varnish (FV), G3 - potassium oxalate (PO), G4 - 2-step self-etching adhesive system (AS), G5 - diode laser (DL). The specimens were cleaved in the lingual buccaldirection, prepared for analysis by Scanning Electron Microscope and the surface and interior of the dentinal tubules were observed at 1500× magnification. Results: In the control group, the dentin etching promoted smear layer removal and exposure of dentinal tubules. In the group of fluoride varnish, a film was observed on the surface, with plugs of varnish into tubules. In the group of oxalate, partial obliteration of the tubular entrances was observed. In the group of the adhesive system, the tubules were obstructed through the formation of hybrid layer and a physical barrier on the surface. In the group of the diode laser, dentin melting and solidification with partial occlusion of dentinal tubules were observed. Conclusions: All desensitizing agents evaluated demonstrated ability to modify the surface of dentin, with partial or total occlusion of dentinal tubules. Thus, it is suggested to do more clinical studies to verify the effectiveness of the findings. PMID:25606322

  3. Influence of Nd:YAG laser irradiation on an adhesive restorative procedure.

    PubMed

    Franke, Margarete; Taylor, Arthur Westphal; Lago, Alexandre; Fredel, Márcio Celso

    2006-01-01

    Hard tissue modification by means of laser irradiation is becoming popular in dentistry, since it promotes assorted responses between the tooth and the restorative material. Some studies on the bond strength of adhesive systems to Nd:YAG irradiated teeth have shown distinctive behaviors when irradiation was applied before or after the adhesive agent. This study evaluated the microtensile bond strength of a commercial adhesive system to dentin irradiated with Nd:YAG laser after adhesive application but prior to polymerization. The experiment was conducted in vitro, using freshly extracted human teeth as samples. For the microtensile test, the teeth were separated into 4 different groups according to the energy density of laser irradiation: 0, 5, 10 and 50 J/cm2. The data was analyzed with analysis of variance (ANOVA) and LSD tests, and the results indicated that the group that was irradiated with 5 J/cm2 had significantly higher bond strength values. Adhesive penetration on the etched dentin was observed by scanning electron microscopy, where the images showed better adhesive penetration on dentinal tubules after dentin irradiation with 5 J/cm2. Based on the results of this study, it is possible to conclude that irradiation of dentin with the Nd:YAG laser at low energy densities after application of the adhesive but prior to polymerization might be positive for the adhesive restorative process. PMID:17024950

  4. Comparative SEM study on the effect of different demineralization methods with tetracycline HCl on healthy root surfaces.

    PubMed

    Işik, G; Ince, S; Sağlam, F; Onan, U

    1997-09-01

    Periodontal regeneration through the use of root demineralization received a lot of interest in periodontology. Topical application of acid to dentin surfaces produced a zone of demineralization, exposing dentin collagen fibrils and opening dentin tubules. In this study, the in vitro effects of different tetracycline HCl application techniques were investigated. According to the results of this SEM study, it may be desirable to apply tetracycline HCl using burnishing technique to expose maximum intertubular fibrils and for the tubular openings. However, this technique should be studied when placed in an in vivo system. PMID:9378828

  5. Photodynamic therapy: An adjunct to conventional root canal disinfection strategies.

    PubMed

    Singh, Shipra; Nagpal, Rajni; Manuja, Naveen; Tyagi, Sashi Prabha

    2015-08-01

    Although chemical-based root canal disinfectants are important to reduce microbial loads and remove infected smear layer from root dentin, they have only a limited ability to eliminate biofilm bacteria, especially from root complexities. This paper explores the novel photodynamic therapy (PDT) for antimicrobial disinfection of root canals. The combination of an effective photosensitizer, the appropriate wavelength of light and ambient oxygen is the key factor in PDT. PDT uses a specific wavelength of light to activate a non-toxic dye (photosensitizer), leading to the formation of reactive oxygen species. These reactive oxygen molecules can damage bacterial proteins, membrane lipids and nucleic acids, which promote bacterial cell death. In, addition PDT may enhance cross-linking of collagen fibrils in the dentin matrix and thereby improving dentin stability. The concept of PDT is plausible and could foster new therapy concepts for endodontics. The available knowledge should enable and encourage steps forward into more clinical-oriented research and development. This article discusses PDT as related to root canal disinfection, including its components, mechanism of action, reviews the current endodontic literature and also highlights the shortcomings and advancements in PDT techniques. PMID:25404404

  6. In vitro comparative study of manual and mechanical rotary instrumentation of root canals using computed tomography.

    PubMed

    Limongi, Orlando; de Albuquerque, Diana Santana; Baratto Filho, Flares; Vanni, José Roberto; de Oliveira, Elias P Motcy; Barletta, Fernando Branco

    2007-01-01

    This in vitro study compared, using computed tomography (CT), the amount of dentin removed from root canal walls by manual and mechanical rotary instrumentation techniques. Forty mandibular incisors with dental crown and a single canal were selected. The teeth were randomly assigned to two groups, according to the technique used for root canal preparation: Group I - manual instrumentation with stainless steel files; Group II - mechanical instrumentation with RaCe rotary nickel-titanium instruments. In each tooth, root dentin thickness of the buccal, lingual, mesial and distal surfaces in the apical, middle and cervical thirds of the canal was measured (in mm) using a multislice CT scanner (Siemens Emotion, Duo). Data were stored in the SPSS v. 11.5 and SigmaPlot 2001 v. 7.101 softwares. After crown opening, working length was determined, root canals were instrumented and new CT scans were taken for assessment of root dentin thickness. Pre- and post-instrumentation data were compared and analyzed statistically by ANOVA and Tukey's post-hoc test for significant differences (p=0.05). Based on the findings of this study, it may be concluded that regarding dentin removal from root canal walls during instrumentation, neither of the techniques can be considered more effective than the other. PMID:19031646

  7. Temperature changes inside the molar pulp chamber and on the enamel and root surfaces induced by the CO2 laser beam, in vitro

    NASA Astrophysics Data System (ADS)

    Anic, Ivica; Dzubur, A.; Skala, Karolj; Sutalo, Jozo

    1993-12-01

    The application of the CO2 laser continuous wave to hard dental tissue causes temperature changes on the impact area, on the adjacent area and inside the pulp chamber. The purpose of this study was to investigate the thermal effects induced by the CO2 laser continuous wave, and the temperature flow through adjacent areas. Forty healthy molars, 15 molars with class II amalgam restoration and 10 canines with cervical caries extracted for periodontal reasons were irradiated with laser beam. On the occlusal surface the class I preparation was made just beyond the dentine-enamel junction. Temperature changes were measured at the enamel, root surface and at the cross section of the previously prepared holes 3 mm in diameter which were made 2 mm above the bifurcation level.

  8. Zinc induces apatite and scholzite formation during dentin remineralization.

    PubMed

    Osorio, R; Osorio, E; Cabello, I; Toledano, M

    2014-01-01

    The aim of this study was to ascertain whether zinc may improve the repair ability of demineralized dentin. Dentin disks were demineralized by phosphoric acid during 15 s and immersed in artificial saliva, remineralizing solution, a zinc chloride solution and a zinc oxide solution. Dentin specimens were analyzed after 24 h and 1 month of storage. Surface morphology was assessed by atomic force and scanning electron microscopy, mechanical properties were analyzed by nanohardness testing in a TriboIndenter, and chemical changes at the surfaces were determined by X-ray diffraction, Raman and energy-dispersive elemental analyses. After phosphoric acid application, dentin was only partially demineralized. Demineralized dentin was remineralized after 24 h of storage in any of the tested solutions (nanohardness increased and hydroxylapatite formation was detected by Raman). Remineralization was maintained up to 1 month in dentin stored in remineralizing solution, zinc chloride and zinc oxide. Zinc and phosphate were important for hydroxylapatite homeostasis. Scholzite formation was encountered in dentin stored in zinc-containing solutions. Zinc might allow to reach the balance between dentin demineralization and remineralization processes. PMID:24513585

  9. External Dentin Stimulation Induces ATP Release in Human Teeth.

    PubMed

    Liu, X; Wang, C; Fujita, T; Malmstrom, H S; Nedergaard, M; Ren, Y F; Dirksen, R T

    2015-09-01

    ATP is involved in neurosensory processing, including nociceptive transduction. Thus, ATP signaling may participate in dentin hypersensitivity and dental pain. In this study, we investigated whether pannexins, which can form mechanosensitive ATP-permeable channels, are present in human dental pulp. We also assessed the existence and functional activity of ecto-ATPase for extracellular ATP degradation. We further tested if ATP is released from dental pulp upon dentin mechanical or thermal stimulation that induces dentin hypersensitivity and dental pain and if pannexin or pannexin/gap junction channel blockers reduce stimulation-dependent ATP release. Using immunofluorescence staining, we demonstrated immunoreactivity of pannexin 1 and 2 in odontoblasts and their processes extending into the dentin tubules. Using enzymatic histochemistry staining, we also demonstrated functional ecto-ATPase activity within the odontoblast layer, subodontoblast layer, dental pulp nerve bundles, and blood vessels. Using an ATP bioluminescence assay, we found that mechanical or cold stimulation to the exposed dentin induced ATP release in an in vitro human tooth perfusion model. We further demonstrated that blocking pannexin/gap junction channels with probenecid or carbenoxolone significantly reduced external dentin stimulation-induced ATP release. Our results provide evidence for the existence of functional machinery required for ATP release and degradation in human dental pulp and that pannexin channels are involved in external dentin stimulation-induced ATP release. These findings support a plausible role for ATP signaling in dentin hypersensitivity and dental pain. PMID:26130258

  10. Bonding BisGMA to dentin--a proof of concept for hydrophobic dentin bonding.

    PubMed

    Tay, F R; Pashley, D H; Kapur, R R; Carrilho, M R O; Hur, Y B; Garrett, L V; Tay, K C Y

    2007-11-01

    The use of TEGDMA as a diluent comonomer in the formulation of hydrophobic adhesives for ethanol wet-bonding is a concern, due to its leaching potential, higher water sorption, and bio-incompatibility. This study tested the hypothesis that hydrophobic bonding to acid-etched dentin may be accomplished with the use of ethanol-solvated BisGMA only. Phosphoric-acid-etched, oxalate-occluded, deep coronal dentin bonded under 20 cm water pressure with experimental BisGMA adhesives by ethanol wet-bonding exhibited tensile strengths that were not significantly different from that achieved with OptiBond FL bonded according to the manufacturer-recommended protocol, with similar acid-/base-resistant hybrid layers, resin tags, and nanoleakage distribution. Ethanol replacement of water-saturated dentin produced wider interfibrillar spaces, more extensive shrinkage of the collagen fibrils, and narrower hybrid layers. Experimental BisGMA adhesives provide the proof of concept that relatively hydrophobic resins may be coupled to acid-etched dentin by increasing its hydrophobic characteristics via ethanol replacement. They should be further optimized before clinical application. PMID:17959892

  11. Solvent Retention of Contemporary Commercial Dentin Bonding Agents in a Demineralized Dentin Matrix

    PubMed Central

    Garcia, Georges; Fernandes, Karen Barros Parron; Garcia, Fernanda Cristina Pimentel; D’Alpino, Paulo Henrique Perlatti; da Rocha Svizero, Nádia; Wang, Linda

    2010-01-01

    Objectives: Solvents are ingredients in dentin-bonding agents (DBAs) that are essential to obtain efficient adhesion to dentin under wet-technique bonding protocol. However, an excess of solvents can compromise bonding durability. This study aimed to assess the retention of solvents present in different DBAs after their application to a demineralized dentin matrix. Methods: Thirty-six specimens of bovine dentin were demineralized for 7 days in 0.5M EDTA and divided into six groups n=6 (Scotchbond primer, Adper Single Bond 2, Excite, AdheSE primer, Prime & Bond NT and Xeno III). These specimens were individually saturated by the systems for 5 min and then kept in vials protected against light exposure. Each specimen was measured using a digital balance and then measured at the following intervals 10, 20, 30 sec, 1, 2 and 5 min thereafter. Data were analyzed by two-way ANOVA and Tukey tests (alfa=.05). Results: There were significant differences evident in Excite, Prime & Bond NT at 2 and 5 min, respectively. There was no significant interaction between materials and time in all experimented time evaluated. The amount of solvent spontaneously evaporated was limited even in acetone-based specimens. Conclusions: After DBAs are applied, professionals may facilitate their evaporation, since spontaneous evaporation is limited. PMID:20613918

  12. Biocompatibility of dental materials used in contemporary endodontic therapy: a review. Part 2. Root-canal-filling materials.

    PubMed

    Hauman, C H J; Love, R M

    2003-03-01

    Root-canal-filling materials are either placed directly onto vital periapical tissues or may leach through dentine. The tissue response to these materials therefore becomes important and may influence the outcome of endodontic treatment. This paper is a review of the biocompatibility of contemporary orthograde and retrograde root-canal-filling materials. PMID:12657140

  13. Resistance to compression of weakened roots subjected to different root reconstruction protocols

    PubMed Central

    ZOGHEIB, Lucas Villaça; SAAVEDRA, Guilherme de Siqueira Ferreira Anzaloni; CARDOSO, Paula Elaine; VALERA, Márcia Carneiro; de ARAÚJO, Maria Amélia Máximo

    2011-01-01

    Objective This study evaluated, in vitro, the fracture resistance of human non-vital teeth restored with different reconstruction protocols. Material and methods Forty human anterior roots of similar shape and dimensions were assigned to four groups (n=10), according to the root reconstruction protocol: Group I (control): non-weakened roots with glass fiber post; Group II: roots with composite resin by incremental technique and glass fiber post; Group III: roots with accessory glass fiber posts and glass fiber post; and Group IV: roots with anatomic glass fiber post technique. Following post cementation and core reconstruction, the roots were embedded in chemically activated acrylic resin and submitted to fracture resistance testing, with a compressive load at an angle of 45º in relation to the long axis of the root at a speed of 0.5 mm/min until fracture. All data were statistically analyzed with bilateral Dunnett's test (α=0.05). Results Group I presented higher mean values of fracture resistance when compared with the three experimental groups, which, in turn, presented similar resistance to fracture among each other. None of the techniques of root reconstruction with intraradicular posts improved root strength, and the incremental technique was suggested as being the most recommendable, since the type of fracture that occurred allowed the remaining dental structure to be repaired. Conclusion The results of this in vitro study suggest that the healthy remaining radicular dentin is more important to increase fracture resistance than the root reconstruction protocol. PMID:22231002

  14. The physiologic sclerotic dentin: A literature-based hypothesis.

    PubMed

    Kabartai, F; Hoffmann, T; Hannig, C

    2015-12-01

    Despite the many hypotheses trying to explain how the physiologic sclerotic dentin is formed, there has been so far no convincing explanation for all of its observations. In this review, we tried to make a hypothesis based on the facts published to date. We found that the apoptosis of odontoblasts, which takes place after the formation of the apical constriction, may be the key-factor for the development of physiologic sclerotic dentin, because the resulting apoptotic bodies cannot be eliminated through phagocytosis and become trapped within the dentinal tubules due to the continuous formation of secondary dentin. The apoptotic bodies suffer later from a secondary or apoptotic necrosis leading to the release of the internal contents of pyrophosphate and hydrogen phosphate. Pyrophosphate can dehydrate the dentin and hydrogen phosphate can demineralize it, leading to the release of Ca(2+) ions which then contribute to the intratubular mineralization. PMID:26404871

  15. Influence of Ultrasonic Irrigation and Chloroform on Cleanliness of Dentinal Tubules During Endodontic Retreatment-An Invitro SEM Study

    PubMed Central

    Singhal, Anurag; Gurtu, Anuraag; Vinayak, Vineet

    2015-01-01

    Background Ultrasonic irrigation has been proved for its remarkable cleaning efficiency in the field of endodontics. But its role in endodontic re-treatment has been understated. There is not much data available to understand the effect of ultrasonic irrigation for the evaluation of cleanliness of dentinal tubules when it is used with or without chloroform, a gutta percha solvent during endodontic retreatment. Aim To compare the influence of ultrasonic irrigation with syringe irrigation on cleanliness of dentinal tubules after gutta perch removal for endodontic retreatment with or without the use of chloroform a gutta percha solvent using scanning electron microscope (SEM). Materials and Methods Freshly extracted 45 human mandibular premolar teeth for periodontal and orthodontic reasons were taken and were occlusally adjusted to a working length of 19 mm. The root canals of all teeth were prepared chemo mechanically to a master apical file size 40 and were divided in various groups. In Group 1 (n = 5; control group), the canals remained unfilled. In Groups 2 and 3 (n = 20 each), the canals were filled using lateral compaction with gutta-percha and AH plus sealer, removal of root fillings was undertaken after 2 weeks using Gates Glidden drills and H files without chloroform in Group 2 and with chloroform in group 3. The specimen of Group 2 and 3 were further divided into two subgroups I and II (n=10). In subgroup I, irrigation was done using side vented needles and sodium hypochlorite. In subgroup II irrigation was done using passive ultrasonic irrigation with sodium hypochlorite. Thereafter, the roots were split and the sections were observed under SEM. The number of occluded dentinal tubules /total number of dentinal tubules were calculated for the coronal, middle and apical third of each root half. Statistical analysis was performed using one-way ANOVA followed by Tukey’s test using standardized technique. Result Results indicated that the cleanest dentinal

  16. Astacin Proteases Cleave Dentin Sialophosphoprotein (Dspp) to Generate Dentin Phosphoprotein (Dpp)

    PubMed Central

    Tsuchiya, Shuhei; Simmer, James P; Hu, Jan C-C; Richardson, Amelia S; Yamakoshi, Fumiko; Yamakoshi, Yasuo

    2011-01-01

    Dentin sialophosphoprotein (Dspp) is critical for proper dentin biomineralization because genetic defects in DSPP cause dentin dysplasia type II and dentinogenesis imperfecta types II and III. Dspp is processed by proteases into smaller subunits; the initial cleavage releases dentin phosphoprotein (Dpp). We incubated fluorescence resonance energy transfer (FRET) peptides containing the amino acid context of the Dpp cleavage site (YEFDGKSMQGDDPN, designated Dspp-FRET) or a mutant version of that context (YEFDGKSIEGDDPN, designated mutDspp-FRET) with BMP-1, MEP1A, MEP1B, MMP-2, MMP-8, MMP-9, MT1-MMP, MT3-MMP, Klk4, MMP-20, plasmin, or porcine Dpp and characterized the peptide cleavage products. Only BMP-1, MEP1A, and MEP1B cleaved Dspp-FRET at the G–D peptide bond that releases Dpp from Dspp in vivo. We isolated Dspp proteoglycan from dentin power and incubated it with the three enzymes that cleaved Dspp-FRET at the G–D bond. In each case, the released Dpp domain was isolated, and its N-terminus was characterized by Edman degradation. BMP-1 and MEP1A both cleaved native Dspp at the correct site to generate Dpp, making both these enzymes prime candidates for the protease that cleaves Dspp in vivo. MEP1B was able to degrade Dpp when the Dpp was at sufficiently high concentration to deplete free calcium ion concentration. Immunohistochemistry of developing porcine molars demonstrated that astacins are expressed by odontoblasts, a result that is consistent with RT-PCR analyses. We conclude that during odontogenesis, astacins in the predentin matrix cleave Dspp before the DDPN sequence at the N-terminus of Dpp to release Dpp from the parent Dspp protein. © 2011 American Society for Bone and Mineral Research. PMID:20687161

  17. Tertiary Dentin Formation after Indirect Pulp Capping Using Protein CPNE7.

    PubMed

    Choung, H W; Lee, D S; Lee, Ji-Hyun; Shon, W J; Lee, Jong-Ho; Ku, Y; Park, J C

    2016-07-01

    If there is a partial loss of dentin, the exposed dentinal surface should be protected by an indirect pulp capping (IPC) procedure to preserve pulp vitality and prevent symptoms of dentin hypersensitivity. In our previous study, copine7 (CPNE7) induced odontoblast differentiation in vitro and promoted dentin formation in vivo. The aim of this study was to investigate the possibility of IPC therapy using the CPNE7 protein at the exposed dentinal surface and the resulting effects on tertiary dentin formation in a beagle model. CPNE7 promoted mineralization of odontoblasts and had high calcium ion-binding capacity. The in vivo IPC model with canine teeth showed that regeneration of physiologic reactionary dentin with dentinal tubule structures was clearly observed beneath the remaining dentin in the CPNE7 group, whereas irregular features of reparative dentin were generated in the mineral trioxide aggregate (MTA) group. The CPNE7+MTA group also showed typical reactionary dentin without reparative dentin, showing synergistic effects of CPNE7 with MTA. A scanning electron microscopy analysis showed that dentinal tubules beneath the original dentin were occluded by the deposition of peritubular dentin in the CPNE7 and CPNE7+MTA groups, whereas those in the control group were opened. Therefore, CPNE7 may be able to serve as a novel IPC material and improve symptoms of dentin hypersensitivity. PMID:27013639

  18. 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

  19. Site specific properties of carious dentin matrices biomodified with collagen cross-linkers

    PubMed Central

    Bedran-Russo, Ana K.; Karol, Sachin; Pashley, David H.; Viana, Grace

    2014-01-01

    Purpose To assess in non-cavitated carious teeth the mechanical properties of dentin matrix by measuring its reduced modulus of elasticity and the effect of dentin biomodification strategies on three dentin matrix zones: caries-affected, apparently normal dentin below caries-affected zone and sound dentin far from carious site. Methods Nano-indentations were performed on dentin matrices of carious molars before and after surface modification using known cross-linking agents (glutaraldehyde, proanthocyanidins from grape seed extract and carbodiimide). Results Statistically significant differences were observed between dentin zones of demineralized dentin prior to surface biomodification (P< 0.05). Following surface modification, there were no statistically significant differences between dentin zones (P< 0.05). An average increase of 30-fold, 2-fold and 2.2-fold of the reduced modulus of elasticity was observed following treatments of the three dentin zones with proanthocyanidin, carbodiimide and glutaraldehyde, respectively. PMID:24479274

  20. Morphometric evaluation and planning of anticurvature filing in roots of maxillary and mandibular molars.

    PubMed

    Oliveira, Maria Antonieta Veloso Carvalho; Venâncio, Jessyca Figueira; Raposo, Luís Henrique Araújo; Barbosa Júnior, Nelson; Biffi, João Carlos Gabrielli

    2015-01-01

    This study aimed to guide the planning of anticurvature filing using pre-determined anatomical points on teeth to establish directions for proper implementation of the technique. Two hundred digital periapical radiographs of human molar teeth were selected and divided into two groups (n = 100): MX (maxillary) and MD (mandibular) molars. Mesiobuccal roots were considered for the MX group and mesial roots for the MD group. Pre-determined anatomical points required for planning the anticurvature filing on the root canal path were located, and the distances between these points obtained. The anticurvature filing was simulated in two different protocols for each group, and the region of dentin removal and the remaining dentin thickness were measured in the safety and danger zones of the root canals. Statistical analysis was carried out at a significance level of 5%. The distances between the anatomical points and the thickness of remaining dentin showed significant differences when the two groups were compared (p < 0.001). No significant differences were found between the two experimental groups regarding the area of dentin removal at the root region, but differences were detected in comparison with dentin removal at the crown (p < 0.001). In terms of wear produced after simulation of both anticurvature filing protocols, significant differences were verified for all regions, except for the dentin remaining at the danger zone. The radiographic location of anatomical points allows for planning and implementation of controlled and efficient anticurvature filing and can be performed in the same manner for maxillary and mandibular molars. PMID:25466326

  1. Micromechanical testing of the dentin hybrid zone formed by all-in-one adhesive system in sound human dentin

    NASA Astrophysics Data System (ADS)

    Koytchev, E.; Datcheva, M.; Iankov, R.

    2015-10-01

    This study explored the spatial variations in mechanical behavior of the dentin hybrid layer formed by a single step (one bottle) dentin adhesive system. Objective. The objectives were to: (1) evaluate the mechanical behavior of the hybrid zone formed by a single sep dentin adhesive system using nanoindentation technique, (2) compare the indentation moduli (EIT) and indentation hardness (HIT) of human dentin and the hybrid zone, and (3) assess the importance of specimen hydration on the nanoindentation response. Methods. Specimens of human dentin, treated with commercial single step resin adhesive and restored with composite material were evaluated using a nanoindenter in a load-displacement control mode. The load and displacement responses were used to perform nanoindentation characterization of dentin and the hybrid layer and estimate EIT and HIT, using Oliver & Pharr approximation method. Results. In hydrated state, EIT for dentin and hybrid layer were 18.214 ± 1.30 GPa and 12.535 ± 0.19 GPa respectively. For HIT, also in hydrated state, the values in dentin and hybrid layer were 0.56 ± 0.06 GPa and 0.36 ± 0.005 GPa respectively. Viscoelastic deformation of the dentin hybrid zone exceeded that occuring in regions of uniform dentin tissue. The load displacement curves of the two zones were also estimated and analyzed. They generally follow the same pattern without any noticeable pop-ins or irregularities. Significance. The microstructure and hydration play critical roles on the mechanical behavior of the hybrid layer and nanoindentation provides a potent measurment tool for identifying the spatial variations.

  2. Effect of different disinfectant methods on the initial microtensile bond strength of a self-etch adhesive to dentin.

    PubMed

    Dalkilic, Evrim Eliguzeloglu; Arisu, Hacer Deniz; Kivanc, Bagdagul Helvacioglu; Uctasli, Mine Betul; Omurlu, Huma

    2012-07-01

    The aim of this in vitro study was to evaluate the effect of different disinfection methods on the initial microtensile bond strength of a two-step, self-etch adhesive to dentin. Twenty mandibular molars were sectioned parallel to the occlusal plane to expose the mid-coronal dentin. All of the teeth were divided into four groups (n = 5 per group): (1) in group OZ, the dentin surfaces were exposed to ozone gas from the Ozonytron X delivery system (OzonyTron X-Bioozonix, Munich, Germany), (2) in group ND, the dentin surfaces were irradiated with an Nd:YAG laser (Pulsmaster 600 IQ, American Dental Technologies, U.S.), (3) in group CHX, the dentin surfaces were treated with a 2% chlorhexidine solution, and (4) in the control group, no treatment was applied. In all of the groups, the teeth were restored with Clearfil SE Bond (Kuraray, Tokyo, Japan) and Clearfil Majesty Posterior (Kuraray, Tokyo, Japan), according to the manufacturer's instructions. The teeth were sectioned perpendicular to the bonded surface (surface area of approximately 1 mm(2)). Thus, six to seven specimens were obtained from each tooth, and a total of 34 specimens were analyzed in each group. The specimens were attached to the microtensile test machine (Micro Tensile Tester, T-61010 K, Bisco, U.S.). The data was analyzed using the one-way analysis of variance (ANOVA) and Tukey test (p < 0.05). Fracture modes of each specimen were determined using a stereomicroscope (SZ-PT Olympus, Tokyo, Japan) and a scanning electron microscope (SEM). The lowest bond strength occurred in the OZ group. Significant differences were determined only between group OZ and the other groups (group ND, group CHX, and control group) (p < 0.05). In conclusion, although ozone decreased the microtensile bond strength of the self-etch adhesive system to dentin, the Nd:YAG laser and 2% chlorhexidine did not change the microtensile bond strength so in context of the present study it would appear that the Nd:YAG laser and 2

  3. Methods for studying tooth root cementum by light microscopy.

    PubMed

    Foster, Brian L

    2012-09-01

    The tooth root cementum is a thin, mineralized tissue covering the root dentin that is present primarily as acellular cementum on the cervical root and cellular cementum covering the apical root. While cementum shares many properties in common with bone and dentin, it is a unique mineralized tissue and acellular cementum is critical for attachment of the tooth to the surrounding periodontal ligament (PDL). Resources for methodologies for hard tissues often overlook cementum and approaches that may be of value for studying this tissue. To address this issue, this report offers detailed methodology, as well as comparisons of several histological and immunohistochemical stains available for imaging the cementum-PDL complex by light microscopy. Notably, the infrequently used Alcian blue stain with nuclear fast red counterstain provided utility in imaging cementum in mouse, porcine and human teeth. While no truly unique extracellular matrix markers have been identified to differentiate cementum from the other hard tissues, immunohistochemistry for detection of bone sialoprotein (BSP), osteopontin (OPN), and dentin matrix protein 1 (DMP1) is a reliable approach for studying both acellular and cellular cementum and providing insight into developmental biology of these tissues. Histological and immunohistochemical approaches provide insight on developmental biology of cementum. PMID:22996273

  4. Carbodiimide Inactivation of MMPs and Effect on Dentin Bonding

    PubMed Central

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

    2014-01-01

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

  5. Carbodiimide inactivation of MMPs and effect on dentin bonding.

    PubMed

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

    2014-03-01

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

  6. Dentin regeneration using deciduous pulp stem/progenitor cells.

    PubMed

    Zheng, Y; Wang, X Y; Wang, Y M; Liu, X Y; Zhang, C M; Hou, B X; Wang, S L

    2012-07-01

    Reparative dentin formation is essential for maintaining the integrity of dentin structure during disease or trauma. In this study, we investigated stem/progenitor cell-based tissue engineering for dentin regeneration in a large animal model. Porcine deciduous pulp stem/progenitor cells (PDPSCs) were mixed with a beta-tricalcium phosphate (β-TCP) scaffold for dentin regeneration. Different concentrations of PDPSCs were tested to determine the optimal density for dentin regeneration. Aliquots of 5×10(5) PDPSCs in 1 mL resulted in the highest number of cells attached to the scaffold and the greatest alkaline phosphatase activity. We labeled PDPSCs with green fluorescent protein (GFP) and used the optimal cell numbers mixed with β-TCP to repair pulp chamber roof defects in the premolars of swine. Four weeks after transplantation, GFP-positive PDPSCs were observed in PDPSC-embedded scaffold constructs. At 16 weeks after transplantation, the PDPSCs mixed with β-TCP significantly regenerated the dentin-like structures and nearly completely restored the pulp chamber roof defects. This study demonstrated that the PDPSC/scaffold construct was useful in direct pulp-capping and provides pre-clinical evidence for stem/progenitor cell-based dentin regeneration. PMID:22660968

  7. Spectroscopic and morphologic characterization of the dentin/adhesive interface

    NASA Astrophysics Data System (ADS)

    Lemor, R. M.; Kruger, Michael B.; Wieliczka, David M.; Swafford, Jim R.; Spencer, Paulette

    1999-01-01

    The potential environmental risks associated with mercury release have forced many European countries to ban the use of dental amalgam. Alternative materials such as composite resins do not provide the clinical function for the length of time characteristically associated with dental amalgam. The weak link in the composite restoration is the dentin/adhesive bond. The purpose of this study was to correlate morphologic characterization of the dentin/adhesive bond with chemical analyses using micro- Fourier transform infrared and micro-Raman spectroscopy. A commercial dental adhesive was placed on dentin substrates cut from extracted, unerupted human third molars. Sections of the dentin/adhesive interface were investigated using infrared radiation produced at the Aladdin synchrotron source; visible radiation from a Kr+ laser was used for the micro-Raman spectroscopy. Sections of the dentin/adhesive interface, differentially stained to identify protein, mineral, and adhesive, were examined using light microscopy. Due to its limited spatial resolution and the unknown sample thickness the infrared results cannot be used quantitatively in determining the extent of diffusion. The results from the micro-Raman spectroscopy and light microscopy indicate exposed protein at the dentin/adhesive interface. Using a laser that reduces background fluorescence, the micro-Raman spectroscopy provides quantitative chemical and morphologic information on the dentin/adhesive interface. The staining procedure is sensitive to sites of pure protein and thus, complements the Raman results.

  8. Mutations in COL1A1 Gene Change Dentin Nanostructure.

    PubMed

    Duan, Xiaohong; Liu, Zhenxia; Gan, Yunna; Xia, Dan; Li, Qiang; Li, Yanling; Yang, Jiaji; Gao, Shan; Dong, Mingdong

    2016-04-01

    Although many studies have attempted to associate specific gene mutations with dentin phenotypic severity, it remains unknown how the mutations in COL1A1 gene influence the mechanical behavior of dentin collagen and matrix. Here, we reported one osteogenesis imperfecta (OI) pedigree caused by two new inserting mutations in exon 5 of COL1A1 (NM_000088.3:c.440_441insT;c.441_442insA), which resulted in the unstable expression of COL1A1 mRNA and half quantity of procollagen production. We investigated the morphological and mechanical features of proband's dentin using atomic force microscope (AFM), scanning electron microscope, and transmission electron microscope. Increased D-periodic spacing, variably enlarged collagen fibrils coating with fewer minerals were found in the mutated collagen. AFM analysis demonstrated rougher dentin surface and sparsely decreased Young's modulus in proband's dentin. We believe that our findings provide new insights into the genetic-/nano- mechanisms of dentin diseases, and may well explain OI dentin features with reduced mechanical strength and a lower crosslinked density. Anat Rec, 299:511-519, 2016. © 2015 Wiley Periodicals, Inc. PMID:26694865

  9. Dentin Biomodification: Strategies, Renewable Resources and Clinical Applications

    PubMed Central

    Bedran-Russo, Ana K.; Pauli, Guido F.; Chen, Shao-Nong; McAlpine, James; Castellan, Carina S.; Phansalkar, Rasika S; Aguiar, Thaiane R.; Vidal, Cristina M.P.; Napotilano, José; Nam, Joo-Won; Leme, Ariene A.

    2014-01-01

    Objectives The biomodification of dentin is a biomimetic approach, mediated by bioactive agents, to enhance and reinforce the dentin by locally altering the biochemistry and biomechanical properties. This review provides an overview of key dentin matrix components, targeting effects of biomodification strategies, the chemistry of renewable natural sources, and current research on their potential clinical applications. Methods The PubMed database and collected literature were used as a resource for peer-reviewed articles to highlight the topics of dentin hierarchical structure, biomodification agents, and laboratorial investigations of their clinical applications. In addition, new data is presented on laboratorial methods for the standardization of proanthocyanidin-rich preparations as a renewable source of plant-derived biomodification agents. Results Biomodification agents can be categorized as physical methods and chemical agents. Synthetic and naturally occurring chemical strategies present distinctive mechanism of interaction with the tissue. Initially thought to be driven only by inter- or intra-molecular collagen induced non-enzymatic collagen cross-linking, multiple interactions with other dentin components are fundamental for the long-term biomechanics and biostability of the tissue. Oligomeric proanthocyanidins show promising bioactivity, and their chemical complexity requires systematic evaluation of the active compounds to produce a fully standardized intervention material from renewable resource, prior to their detailed clinical evaluation. Significance Understanding the hierarchical structure of dentin and the targeting effect of the bioactive compounds will establish their use in both dentin-biomaterials interface and caries management. PMID:24309436

  10. Effect of citric acid, tetracycline, and doxycycline on instrumented periodontally involved root surfaces: A SEM study

    PubMed Central

    Chahal, Gurparkash Singh; Chhina, Kamalpreet; Chhabra, Vipin; Bhatnagar, Rakhi; Chahal, Amna

    2014-01-01

    Background: A surface smear layer consisting of organic and inorganic material is formed on the root surface following mechanical instrumentation and may inhibit the formation of new connective tissue attachment to the root surface. Modification of the tooth surface by root conditioning has resulted in improved connective tissue attachment and has advanced the goal of reconstructive periodontal treatment. Aim: The aim of this study was to compare the effects of citric acid, tetracycline, and doxycycline on the instrumented periodontally involved root surfaces in vitro using a scanning electron microscope. Settings and Design: A total of 45 dentin samples obtained from 15 extracted, scaled, and root planed teeth were divided into three groups. Materials and Methods: The root conditioning agents were applied with cotton pellets using the Passive burnishing technique for 5 minutes. The samples were then examined by the scanning electron microscope. Statistical Analysis Used: The statistical analysis was carried out using Statistical Package for Social Sciences (SPSS Inc., Chicago, IL, version 15.0 for Windows). For all quantitative variables means and standard deviations were calculated and compared. For more than two groups ANOVA was applied. For multiple comparisons post hoc tests with Bonferroni correction was used. Results: Upon statistical analysis the root conditioning agents used in this study were found to be effective in removing the smear layer, uncovering and widening the dentin tubules and unmasking the dentin collagen matrix. Conclusion: Tetracycline HCl was found to be the best root conditioner among the three agents used. PMID:24744541

  11. Use of Poly (Amidoamine) Dendrimer for Dentinal Tubule Occlusion: A Preliminary Study

    PubMed Central

    Wang, Tianda; Yang, Sheng; Wang, Lei; Feng, Hailan

    2015-01-01

    The occlusion of dentinal tubules is an effective method to alleviate the symptoms caused by dentin hypersensitivity, a significant health problem in dentistry and daily life. The in situ mineralization within dentinal tubules is a promising treatment for dentin hypersensitivity as it induces the formation of mineral on the sensitive regions and occludes the dentinal tubules. This study was carried out to evaluate the in vitro effect of a whole generation poly(amidoamine) (PAMAM) dendrimer (G3.0) on dentinal tubule occlusion by inducing mineralization within dentinal tubules. Dentin discs were treated with PAMAM dendrimers using two methods, followed by the in vitro characterization using Attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM) and Energy-Dispersive X-ray Spectroscopy (EDS). These results showed that G3.0 PAMAM dendrimers coated on dentin surface and infiltrated in dentinal tubules could induce hydroxyapatite formation and resulted in effective dentinal tubule occlusion. Moreover, crosslinked PAMAM dendrimers could induce the remineralization of demineralized dentin and thus had the potential in dentinal tubule occlusion. In this in vitro study, dentinal tubules occlusion could be achieved by using PAMAM dendrimers. This could lead to the development of a new therapeutic technique for the treatment of dentin hypersensitivity. PMID:25885090

  12. Use of poly (amidoamine) dendrimer for dentinal tubule occlusion: a preliminary study.

    PubMed

    Wang, Tianda; Yang, Sheng; Wang, Lei; Feng, Hailan

    2015-01-01

    The occlusion of dentinal tubules is an effective method to alleviate the symptoms caused by dentin hypersensitivity, a significant health problem in dentistry and daily life. The in situ mineralization within dentinal tubules is a promising treatment for dentin hypersensitivity as it induces the formation of mineral on the sensitive regions and occludes the dentinal tubules. This study was carried out to evaluate the in vitro effect of a whole generation poly(amidoamine) (PAMAM) dendrimer (G3.0) on dentinal tubule occlusion by inducing mineralization within dentinal tubules. Dentin discs were treated with PAMAM dendrimers using two methods, followed by the in vitro characterization using Attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM) and Energy-Dispersive X-ray Spectroscopy (EDS). These results showed that G3.0 PAMAM dendrimers coated on dentin surface and infiltrated in dentinal tubules could induce hydroxyapatite formation and resulted in effective dentinal tubule occlusion. Moreover, crosslinked PAMAM dendrimers could induce the remineralization of demineralized dentin and thus had the potential in dentinal tubule occlusion. In this in vitro study, dentinal tubules occlusion could be achieved by using PAMAM dendrimers. This could lead to the development of a new therapeutic technique for the treatment of dentin hypersensitivity. PMID:25885090

  13. Development of an antibacterial root canal filling system containing MDPB.

    PubMed

    Kitagawa, R; Kitagawa, H; Izutani, N; Hirose, N; Hayashi, M; Imazato, S

    2014-12-01

    An antibacterial monomer 12-methacryloyloxydodecylpyridinum bromide (MDPB)-containing experimental, chemically cured primer was prepared to develop a new resin-based root canal filling system. This study investigated the antibacterial effects of the MDPB-containing primer (experimental primer [EP]) against Enterococcus faecalis and assessed the in vitro bonding and sealing abilities of the filling system, consisting of EP and a Bis-GMA-based sealer resin. Antibacterial effects of EP were evaluated by contact with planktonic or adherent bacteria for 30 or 60 sec, and the viable bacterial number was counted. The antibacterial effects against E. faecalis in dentinal tubules were also assessed, according to a root canal infection model. Bonding and sealing abilities of the experimental filling system were examined by microtensile bond strength tests and leakage tests based on fluid filtration methods. Significantly greater reduction in viable bacteria in planktonic and adherent form was obtained by short-period contact with EP compared with the control primer (without MDPB) or with the proprietary (Epiphany) primer (p < .05). Significantly greater bactericidal effects of the EP inside the dentinal tubule of root, as opposed to the control primer or Epiphany primer, were confirmed according to a root canal infection model (p < .05), and 100% killing of E. faecalis could be obtained by the application of EP after irrigation with a 5% sodium hypochlorite solution. The experimental endodontic filling system demonstrated significantly greater bond strength to root dentin than Epiphany sealer system (Epiphany primer and Epiphany Root Canal Sealant; p < .05), showing formation of resin tags and a hybridized layer. Leakage tests clarified that the experimental system provided excellent sealing. This study confirmed that the MDPB-containing experimental antibacterial primer has the ability to effectively disinfect the root canal. Additionally, the experimental root canal

  14. Development of an Antibacterial Root Canal Filling System Containing MDPB

    PubMed Central

    Kitagawa, R.; Kitagawa, H.; Izutani, N.; Hirose, N.; Hayashi, M.; Imazato, S.

    2014-01-01

    An antibacterial monomer 12-methacryloyloxydodecylpyridinum bromide (MDPB)-containing experimental, chemically cured primer was prepared to develop a new resin-based root canal filling system. This study investigated the antibacterial effects of the MDPB-containing primer (experimental primer [EP]) against Enterococcus faecalis and assessed the in vitro bonding and sealing abilities of the filling system, consisting of EP and a Bis-GMA-based sealer resin. Antibacterial effects of EP were evaluated by contact with planktonic or adherent bacteria for 30 or 60 sec, and the viable bacterial number was counted. The antibacterial effects against E. faecalis in dentinal tubules were also assessed, according to a root canal infection model. Bonding and sealing abilities of the experimental filling system were examined by microtensile bond strength tests and leakage tests based on fluid filtration methods. Significantly greater reduction in viable bacteria in planktonic and adherent form was obtained by short-period contact with EP compared with the control primer (without MDPB) or with the proprietary (Epiphany) primer (p < .05). Significantly greater bactericidal effects of the EP inside the dentinal tubule of root, as opposed to the control primer or Epiphany primer, were confirmed according to a root canal infection model (p < .05), and 100% killing of E. faecalis could be obtained by the application of EP after irrigation with a 5% sodium hypochlorite solution. The experimental endodontic filling system demonstrated significantly greater bond strength to root dentin than Epiphany sealer system (Epiphany primer and Epiphany Root Canal Sealant; p < .05), showing formation of resin tags and a hybridized layer. Leakage tests clarified that the experimental system provided excellent sealing. This study confirmed that the MDPB-containing experimental antibacterial primer has the ability to effectively disinfect the root canal. Additionally, the experimental root canal

  15. Adhesive sealing of dentin surfaces in vitro: A review

    PubMed Central

    Abu-Nawareg, Manar M; Zidan, Ahmed Z; Zhou, Jianfeng; Agee, Kelli; Chiba, Ayaka; Tagami, Jungi; Pashley, David H

    2016-01-01

    Purpose The purpose of this review is to describe the evolution of the use of dental adhesives to form a tight seal of freshly prepared dentin to protect the pulp from bacterial products, during the time between crown preparation and final cementum of full crowns. The evolution of these “immediate dentin sealants” follows the evolution of dental adhesives, in general. That is, they began with multiple-step, etch-and-rinse adhesives, and then switched to the use of simplified adhesives. Methods Literature was reviewed for evidence that bacteria or bacterial products diffusing across dentin can irritate pulpal tissues before and after smear layer removal. Smear layers can be solubilized by plaque organisms within 7–10 days if they are directly exposed to oral fluids. It is likely that smear layers covered by temporary restorations may last more than one month. As long as smear layers remain in place, they can partially seal dentin. Thus, many in vitro studies evaluating the sealing ability of adhesive resins use smear layer-covered dentin as a reference condition. Surprisingly, many adhesives do not seal dentin as well as do smear layers. Results Both in vitro and in vivo studies show that resin-covered dentin allows dentinal fluid to cross polymerized resins. The use of simplified single bottle adhesives to seal dentin was a step backwards. Currently, most authorities use either 3-step adhesives such as Scotchbond Multi-Purposea or OptiBond FLb or two-step self-etching primer adhesives, such as Clearfil SEc, Unifil Bondd or AdheSEe, respectfully. PMID:26846037

  16. Role of Dentin MMPs in Caries Progression and Bond Stability

    PubMed Central

    Mazzoni, A.; Tjäderhane, L.; Checchi, V.; Di Lenarda, R.; Salo, T.; Tay, F.R.; Pashley, D.H.

    2015-01-01

    Dentin can be described as a biological composite with collagen matrix embedded with nanosized hydroxyapatite mineral crystallites. Matrix metalloproteinases (MMPs) and cysteine cathepsins are families of endopeptidases. Enzymes of both families are present in dentin and collectively capable of degrading virtually all extracellular matrix components. This review describes these enzymes and their presence in dentin, mainly focusing on their role in dentin caries pathogenesis and loss of collagen in the adhesive hybrid layer under composite restorations. MMPs and cysteine cathepsins present in saliva, mineralized dentin, and/or dentinal fluid may affect the dentin caries process at the early phases of demineralization. Changes in collagen and noncollagenous protein structure may participate in observed decreases in mechanical properties of caries-affected dentin and reduce the ability of caries-affected dentin to remineralize. These endogenous enzymes also remain entrapped within the hybrid layer during the resin infiltration process, and the acidic bonding agents themselves (irrespective of whether they are etch-and-rinse or self-etch) can activate these endogenous protease proforms. Since resin impregnation is frequently incomplete, denuded collagen matrices associated with free water (which serves as a collagen cleavage reagent for these endogenous hydrolase enzymes) can be enzymatically disrupted, finally contributing to the degradation of the hybrid layer. There are multiple in vitro and in vivo reports showing that the longevity of the adhesive interface is increased when nonspecific enzyme-inhibiting strategies are used. Different chemicals (i.e., chlorhexidine, galardin, and benzalkonium chloride) or collagen cross-linker agents have been successfully employed as therapeutic primers in the bonding procedure. In addition, the incorporation of enzyme inhibitors (i.e., quaternary ammonium methacrylates) into the resin blends has been recently promoted. This

  17. Role of dentin MMPs in caries progression and bond stability.

    PubMed

    Mazzoni, A; Tjäderhane, L; Checchi, V; Di Lenarda, R; Salo, T; Tay, F R; Pashley, D H; Breschi, L

    2015-02-01

    Dentin can be described as a biological composite with collagen matrix embedded with nanosized hydroxyapatite mineral crystallites. Matrix metalloproteinases (MMPs) and cysteine cathepsins are families of endopeptidases. Enzymes of both families are present in dentin and collectively capable of degrading virtually all extracellular matrix components. This review describes these enzymes and their presence in dentin, mainly focusing on their role in dentin caries pathogenesis and loss of collagen in the adhesive hybrid layer under composite restorations. MMPs and cysteine cathepsins present in saliva, mineralized dentin, and/or dentinal fluid may affect the dentin caries process at the early phases of demineralization. Changes in collagen and noncollagenous protein structure may participate in observed decreases in mechanical properties of caries-affected dentin and reduce the ability of caries-affected dentin to remineralize. These endogenous enzymes also remain entrapped within the hybrid layer during the resin infiltration process, and the acidic bonding agents themselves (irrespective of whether they are etch-and-rinse or self-etch) can activate these endogenous protease proforms. Since resin impregnation is frequently incomplete, denuded collagen matrices associated with free water (which serves as a collagen cleavage reagent for these endogenous hydrolase enzymes) can be enzymatically disrupted, finally contributing to the degradation of the hybrid layer. There are multiple in vitro and in vivo reports showing that the longevity of the adhesive interface is increased when nonspecific enzyme-inhibiting strategies are used. Different chemicals (i.e., chlorhexidine, galardin, and benzalkonium chloride) or collagen cross-linker agents have been successfully employed as therapeutic primers in the bonding procedure. In addition, the incorporation of enzyme inhibitors (i.e., quaternary ammonium methacrylates) into the resin blends has been recently promoted. This

  18. Dentinal tubules revealed with X-ray tensor tomography.

    PubMed

    Jud, Christoph; Schaff, Florian; Zanette, Irene; Wolf, Johannes; Fehringer, Andreas; Pfeiffer, Franz

    2016-09-01

    Dentin is a mineralized material making up most of the tooth bulk. A system of microtubules, so called dentinal tubules, transverses it radially from the pulp chamber to the outside. This highly oriented structure leads to anisotropic mechanical properties directly connected to the tubules orientation and density: the ultimate tensile strength as well as the fracture toughness and the shear strength are largest perpendicular to dentinal tubules. Consequently, the fatigue strength depends on the direction of dentinal tubules, too. However, none of the existing techniques used to investigate teeth provide access to orientation and density of dentinal tubules for an entire specimen in a non-destructive way. In this paper, we measure a third molar human tooth both with conventional micro-CT and X-ray tensor tomography (XTT). While the achievable resolution in micro-CT is too low to directly resolve the dentinal tubules, we provide strong evidence that the direction and density of dentinal tubules can be indirectly measured by XTT, which exploits small-angle X-ray scattering to retrieve a 3D map of scattering tensors. We show that the mean directions of scattering structures correlate to the orientation of dentinal tubules and that the mean effective scattering strength provides an estimation of the relative density of dentinal tubules. Thus, this method could be applied to investigate the connection between tubule orientation and fatigue or tensile properties of teeth for a full sample without cutting one, non-representative peace of tooth out of the full sample. PMID:27424269

  19. Dentin hypersensitivity: etiology, diagnosis and treatment; a literature review.

    PubMed

    Davari, Ar; Ataei, E; Assarzadeh, H

    2013-09-01

    The objective of this review is to inform practitioners about dentin hypersensitivity (DH); to provide a brief overview of the diagnosis, etiology and clinical management of dentin hypersensitivity and to discuss technical approaches to relieve sensitivity. This clinical information is described in the context of the underlying biology. The author used PUBMED to find relevant English-language literature published in the period 1999 to 2010. The author used combinations of the search terms "dentin*", "tooth", "teeth", "hypersensit*", "desensitiz*". Abstracts and also full text articles to identify studies describing etiology, prevalence, clinical features, controlled clinical trials of treatments and relevant laboratory research on mechanisms of action were used. PMID:24724135

  20. Square Root +

    ERIC Educational Resources Information Center

    Frederiksen, John G.

    1969-01-01

    A rational presentation of the so-called long division method for extracting the square root of a number. Diagrams are used to show relationship of this technique to the binomial theorem. Presentation exposes student to many facets of mathematics in addition to the mechanics of funding square root and cube root. Geometry, algebraic statements,…

  1. Scanning electron microscopy of the root surface texture of extracted periodontally diseased teeth following various etching and chelating regimens.

    PubMed

    Bergenholtz, A; Babay, N

    1998-04-01

    Scanning electron microscopy of root surfaces that had been ultrasonically scaled and subjected to various conditioning regimens revealed the presence of two distinct types of cracks: extensive cracks, presumed to have been caused by drying before and during sputter-coating procedures; and smaller cracks that reflected the pattern of the irregular underlying dentin. Both etching and chelating agents appear to cause demineralization of the interfacial layer between cementum and dentin, causing a "peeling off" of cementum and exposure of the underlying dentin. The results suggest that burnishing the scaled root surface with either saline or any of the etching or chelating agents for at least 10 seconds, followed by soaking the cementum in 8% ethylenediaminetetraacetic acid for about 40 seconds, achieved a root surface that might be regarded as optimal for regeneration of periodontal tissues. PMID:9663095

  2. Fatigue of the Resin-Dentin Interface: A New Approach for Evaluating the Durability of Dentin Bonds

    PubMed Central

    Mutluay, Mustafa Murat; Yahyazadefar, Mobin; Ryou, Heonjune; Majd, Hessam; Do, Dominic; Arola, Dwayne

    2013-01-01

    There are concerns regarding the longevity of resin composite restorations and the clinical relevance of in vitro bond strength testing to the durability of dentin bonds in vivo. Objective The objectives of this investigation were to: 1) develop a new method of experimental evaluation for quantifying the durability of dentin bonds, 2) apply this method to characterize the interfacial strength of a selected commercial system under both monotonic and cyclic loading, and 3) distinguish mechanisms contributing to the interface degradation and failure. Methods A new method for fatigue testing the resin-dentin interface was developed based on a four-point flexure arrangement that includes two identical bonded interfaces. Cyclic loading of specimens comprised of coronal dentin bonded to a commercial resin composite and controls of resin composite was performed to failure within a hydrated environment. Scanning electron microscopy and nanoscopic dynamic mechanical analysis were used to evaluate failure mechanisms. Results The fatigue strength of the resin-dentin interface was significantly lower (p≤0.0001) than that of the resin composite and reported for dentin over the entire finite life regime. Defined at 1×107 cycles, the apparent endurance limit of the resin-dentin interface was 13 MPa, in comparison to 48 MPa and 44 MPa for the resin composite and dentin, respectively. The ratio of fully reversed endurance limit to ultimate strength of the interface (0.26) was the lowest of the three materials. Significance The proposed approach for characterizing the fatigue strength of resin-dentin bonds may offer new insights concerning durability of the bonded interface. PMID:23434232

  3. Development of a multifunctional adhesive system for prevention of root caries and secondary caries

    PubMed Central

    Zhang, Ning; Melo, Mary A. S.; Chen, Chen; Liu, Jason; Weir, Michael D.; Bai, Yuxing; Xu, Hockin H. K.

    2015-01-01

    Objectives The objectives of this study were to: (1) develop a novel adhesive for prevention of tooth root caries and secondary caries by possessing a combination of protein-repellent, antibacterial, and remineralization capabilities for the first time; and (2) investigate the effects of 2-methacryloyloxyethyl phosphorylcholine (MPC), dimethylaminohexadecyl methacrylate (DMAHDM), and nanoparticles of amorphous calcium phosphate (NACP) on dentine bond strength, protein-repellent properties, and dental plaque microcosm biofilm response. Methods MPC, DMAHDM and NACP were added into Scotchbond Multi-Purpose primer and adhesive. Dentine shear bond strengths were measured. Adhesive coating thickness, surface texture and dentine-adhesive interfacial structure were examined. Protein adsorption onto adhesive resin surface was determined by the micro bicinchoninic acid method. A human saliva microcosm biofilm model was used to investigate biofilm metabolic activity, colony-forming unit (CFU) counts, and lactic acid production. Results The resin with 7.5% MPC + 5% DMAHDM + 30% NACP did not adversely affect dentine shear bond strength (p > 0.1). The resin with 7.5% MPC + 5% DMAHDM + 30% NACP produced a coating on root dentine with a thickness of approximately 70 μm and completely sealed all the dentinal tubules. The resin with 7.5% MPC + 5% DMAHDM + 30% NACP had 95% reduction in protein adsorption, compared to SBMP control (p < 0.05). The resin with 7.5% MPC + 5% DMAHDM + 30% NACP was strongly antibacterial, with biofilm CFU being four orders of magnitude lower than that of SBMP control. Significance The novel multifunctional adhesive with strong protein-repellent, antibacterial and remineralization properties is promising to coat tooth roots to prevent root caries and secondary caries. The combined use of MPC, DMAHDM and NACP may have wide applicability to bonding agents, cements, sealants and composites to inhibit caries. PMID:26187532

  4. Root Hairs

    PubMed Central

    Grierson, Claire; Nielsen, Erik; Ketelaarc, Tijs; Schiefelbein, John

    2014-01-01

    Roots hairs are cylindrical extensions of root epidermal cells that are important for acquisition of nutrients, microbe interactions, and plant anchorage. The molecular mechanisms involved in the specification, differentiation, and physiology of root hairs in Arabidopsis are reviewed here. Root hair specification in Arabidopsis is determined by position-dependent signaling and molecular feedback loops causing differential accumulation of a WD-bHLH-Myb transcriptional complex. The initiation of root hairs is dependent on the RHD6 bHLH gene family and auxin to define the site of outgrowth. Root hair elongation relies on polarized cell expansion at the growing tip, which involves multiple integrated processes including cell secretion, endomembrane trafficking, cytoskeletal organization, and cell wall modifications. The study of root hair biology in Arabidopsis has provided a model cell type for insights into many aspects of plant development and cell biology. PMID:24982600

  5. Morphology of the dentin structure of sloths Bradypus tridactylus: a light and scanning electron microscopy investigation.

    PubMed

    Santana, L N S; Barbosa, L V M; Teixeira, F B; Costa, A M P; Fernandes, L M P; Lima, R R

    2013-12-01

    The aim of this study was to describe the dentine morphology of sloths (Bradypus tridactylus). The sloth teeth were removed and prepared for light microscopy (LM) and scanning electron microscopy analyses (SEM). LM revealed two patterns of tubular dentins: an outer with dentinary tubules over the all tooth length and one in the inner part with larger diameter and more spaced tubules, when compared to those present in the outer dentine. These findings were confirmed by SEM, which revealed a tubular pattern in the outer dentine like in humans. The inner dentine displayed pared grouped tubules that were characterized as vascular channels. It can be concluded that this sloth species present two types of dentins: an inner dentin (ortodentin) and an outer dentin characterized as a vascular dentin. This suggests a partial evolutive/adaptive process of this dental tissue, as compared to other mammalian species. PMID:23410180

  6. Dentine hypersensitivity: analysis of self-care products.

    PubMed

    Rösing, Cassiano Kuchenbecker; Fiorini, Tiago; Liberman, Diego Nique; Cavagni, Juliano

    2009-01-01

    Dentine hypersensitivity is a condition that is often present in individuals, leading them to seek dental treatment. It has been described as an acute, provoked pain that is not attributable to other dental problems. Its actual prevalence is unknown, but it is interpreted as very unpleasant by individuals. Several therapeutic alternatives are available to manage dentine hypersensitivity, involving both in-office treatment and home-use products. The aim of this literature review was to evaluate self-care products for managing dentine hypersensitivity. Among the products available, dentifrices and fluorides are the most studied self-care products, with positive effects. However, a high percentage of individuals is affected by the placebo effect. Among dentifrices, those containing potassium salts seem to be the most promising. Dental professionals need to understand the advantages and limitations of these therapies and use this knowledge in a positive approach that might help in decreasing dentine hypersensitivity among patients. PMID:19838559

  7. Innovations for combating dentin hypersensitivity: current state of the art.

    PubMed

    Li, Yiming

    2012-06-01

    Dentin hypersensitivity is a common dental complaint, and in severe cases it can impair eating, drinking, and even speaking, thus interfering with the normal daily life of an individual. Throughout years of research, there has been significant advancement in understanding dentin hypersensitivity, and various treatment regimens have been developed for combating the problem. The continued efforts have recently resulted in a novel technology that uses 8% arginine and calcium carbonate for treating dentin hypersensitivity. Formulations of oral care products using this technology--including toothpaste and prophylactic pastes--have demonstrated not only their effectiveness but also their ability to provide instant relief. This paper provides an overview of the etiology of dentin hypersensitivity, the discovery and development of measures for combating the problem, and the available data on the clinical efficacy of products based on 8% arginine and calcium carbonate. PMID:22774324

  8. Role of Alcohol on the Fracture Resistance of Dentin

    SciTech Connect

    Nalla, Ravi K.; Kinney, John H.; Tomsia, Antoni P.; Ritchie,Robert O.

    2006-05-01

    Healthy dentin, the mineralized tissue that makes up the bulk of the tooth, is naturally hydrated in vivo; however, it is known that various chemical reagents including acetone and ethanol can induce dehydration and thereby affect its properties. Here, we seek to investigate this in light of the effect alcohol can have on the mechanical properties of dentin, specifically by measuring the stiffness, strength and toughness of dentin in simulated body fluid and scotch whisky. Results indicate that chemical dehydration induced by the whisky has a significant beneficial effect on the elastic modulus, strength and fracture toughness of dentin. Although this makes teeth more resistant to fracture, the change in properties is fully reversible upon rehydration. This effect is considered to be associated with increased cross-linking of the collagen molecules from intermolecular hydrogen-bonding where water is replaced with weaker hydrogen-bond forming solvents such as alcohol.

  9. Analysis of laser transmission and thermal effects on the inner root surface during periodontal treatment with a 940-nm diode laser in an in vitro pocket model

    NASA Astrophysics Data System (ADS)

    Falkenstein, Fabian; Gutknecht, Norbert; Franzen, René

    2014-12-01

    The purpose of this study was to analyze thermal effects during laser-assisted periodontal treatment. An in vitro model for temperature measurements was developed to investigate different laser settings regarding pulp safety. Additionally, the influence of transmission on pulp temperature elevation was evaluated. Longitudinal root sections were irradiated with a 940-nm diode laser with 1.0 and 1.5 W in continuous wave mode. According to wall thicknesses, irradiation times were adjusted to 20 s for upper and 10 s for lower incisors, respectively. Transmission was relatively low in both upper (4.8% to 8.3% of incident power) and lower incisors (10.2% to 15.0%). Samples were embedded in a polyurethane model and six thermocouples were affixed. Regardless of dentine thickness, the middle third of the root was identified to be the area with the most heat load, where a temperature rise of 7.5°C (1.0 W) and 10.5°C (1.5 W) was registered in upper incisors. A difference of 1.5°C to 3°C was detected in lower incisors compared with uppers. All settings were safe except for 1.5 W, 20 s. Transmission affected heat generation remarkably. The proposed model provides advantages regarding heat transfer and enables for spatially resolved temperature measurements.

  10. Temperature change, dentinal fluid flow and cuspal displacement during resin composite restoration.

    PubMed

    Ratih, D N; Palamara, J E A; Messer, H H

    2007-09-01

    Dentin-bonding agents and resin composite materials typically require light activation for polymerization. Light curing generates heat, which may influence dentinal fluid flow (DFF) and cuspal displacement. This study investigated the relationship among temperature increase, DFF and cuspal displacement in extracted human maxillary premolars with a mesial occlusal distal (MOD) cavity preparation. Two types of curing light were compared. Temperature changes were measured using thermocouples located on the occlusal cavity floor and at the pulp-dentine junction, during polymerization of bonding agent and resin composite material. DFF and cuspal displacement were measured simultaneously using automated flow measurement apparatus and direct current differential transformers respectively. Temperature increases of up to 15 degrees C were recorded during the restoration procedures. A quartz tungsten halogen (QTH) unit produced a significantly greater temperature increase than a light-emitting diode unit and curing of the bonding agent generated less temperature increase than curing of the resin composite. Heating due to exothermic reaction during polymerization of bonding agent and resin was not significantly different between light sources or between bonding and curing (P > 0.05). The QTH unit produced both greater inward fluid flow and cuspal displacement during the irradiation of bonding agent and resin composite than the light-emitting diode unit. There was not a simple relationship between temperature increase, fluid movement and cuspal displacement. From a clinical point of view, the light-emitting diode unit can be considered preferable to the QTH light, because it caused significantly smaller temperature increase, fluid shift and cuspal displacement. PMID:17716269

  11. Morphological effects of MMPs inhibitors on the dentin bonding

    PubMed Central

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

    2015-01-01

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

  12. Comparative evaluation of demineralization of radicular dentin with 17% ethylenediaminetetraacetic acid, 10% citric acid, and MTAD at different time intervals: An in vitro study

    PubMed Central

    Kumar, Yogender; Lohar, Jitendra; Bhat, Sureka; Bhati, Manisha; Gandhi, Aanesh; Mehta, Abhishek

    2016-01-01

    Background: The smear layer has the capability to protect the bacteria within the dentinal tubules from intracanal medicament. After removal of the smear layer from infected root canals, it allows disinfection of the entire root canal. The smear layer compromising the seal between the root canal sealer and root canal wall also decreases the penetration of irrigants into dentinal tubules. Aims: This study compares the amount of phosphorous liberated and demineralization of the radicular dentin with 17% ethylenediaminetetraacetic acid, 10% citric acid and mixture of doxycycline, citric acid, and a detergent at different time intervals. Materials and Methods: Extracted maxillary single-rooted teeth were prepared by using a combination of passive step-back and rotary 0.04 taper nickel-titanium files. Sodium hypochlorite 5.25% and sterile distilled water were used as an intracanal irrigant. The canals were then treated with 5 mL of one of the following solutions such as final rinse sterile distilled water, 5.25% sodium hypochlorite, 17% ethylenediaminetetraacetic acid (EDTA) or mixture of doxycycline, citric acid, and a detergent. The presence or absence of smear layer and the amount of erosion on the surface of the root canal walls at the coronal, middle, and apical portions of each canal were examined under a scanning electron microscope. Statistical Analysis: Data were analyzed by one-way analysis of variance (ANOVA) to determine whether there were significant differences between the groups. Results: The results show that mixture of doxycycline, citric acid, and a detergent is an effective solution for the removal of the smear layer and does not significantly change the structure of the dentinal tubules. Conclusions: In this study, 10% citric acid shows the maximum amount of dimeneralization of radicular dentine followed by mixture of doxycycline, citric acid, and a detergent, and 17% ethylenediaminetetraacetic acid. When all the subgroups were compared, it was seen

  13. Current Advance and Future Prospects of Tissue Engineering Approach to Dentin/Pulp Regenerative Therapy.

    PubMed

    Gong, Ting; Heng, Boon Chin; Lo, Edward Chin Man; Zhang, Chengfei

    2016-01-01

    Recent advances in biomaterial science and tissue engineering technology have greatly spurred the development of regenerative endodontics. This has led to a paradigm shift in endodontic treatment from simply filling the root canal systems with biologically inert materials to restoring the infected dental pulp with functional replacement tissues. Currently, cell transplantation has gained increasing attention as a scientifically valid method for dentin-pulp complex regeneration. This multidisciplinary approach which involves the interplay of three key elements of tissue engineering-stem cells, scaffolds, and signaling molecules-has produced an impressive number of favorable outcomes in preclinical animal studies. Nevertheless, many practical hurdles need to be overcome prior to its application in clinical settings. Apart from the potential health risks of immunological rejection and pathogenic transmission, the lack of a well-established banking system for the isolation and storage of dental-derived stem cells is the most pressing issue that awaits resolution and the properties of supportive scaffold materials vary across different studies and remain inconsistent. This review critically examines the classic triad of tissue engineering utilized in current regenerative endodontics and summarizes the possible techniques developed for dentin/pulp regeneration. PMID:27069484

  14. The role of phosphorylation in dentin phosphoprotein peptide absorption to hydroxyapatite surfaces: a molecular dynamics study

    PubMed Central

    Villarreal-Ramirez, Eduardo; Garduño-Juarez, Ramon; Gericke, Arne; Boskey, Adele

    2015-01-01

    Dentin phosphoprotein (DPP) is a protein expressed mainly in dentin and to a lesser extent in bone. DPP has a disordered structure, rich in glutamic acid, aspartic acid and phosphorylated serine/threonine residues. It has a high capacity for binding to calcium ions and to hydroxyapatite (HA) crystal surfaces. We used molecular dynamics (MD) simulations as a method for virtually screening interactions between DPP motifs and HA. The goal was to determine which motifs are absorbed to HA surfaces. For these simulations, we considered five peptides from the human DPP sequence. All-atom MD simulations were performed using GROMACS, the peptides were oriented parallel to the {100} HA crystal surface, the distance between the HA and the peptide was 3 nm. The system was simulated for 20 ns. Preliminary results show that for the unphosphorylated peptides, the acidic amino acids present an electrostatic attraction where their side chains are oriented towards HA. This attraction, however, is slow to facilitate bulk transport to the crystal surface. On the other hand, the phosphorylated (PP) peptides are rapidly absorbed on the surface of the HA with their centers of mass closer to the HA surface. More importantly, the root mean square fluctuation (RMSF) indicates that the average structures of the phosphorylated peptides are very inflexible and elongate, while that of the unphosphorylated peptides are flexible. Radius of gyration (Rg) analysis showed the compactness of un-phosphorylated peptides is lower than phosphorylated peptides. Phosphorylation of the DPP peptides is necessary for binding to HA surfaces. PMID:25158198

  15. Effects of fresh mineralized dentin and cementum on socket healing: a preliminary study in dogs

    PubMed Central

    Kadkhodazadeh, Mahdi; Ghasemianpour, Majid; Soltanian, Negar; Sultanian, Gholam Reza; Amid, Reza

    2015-01-01

    Objectives Dentin is composed of many minerals and growth factors. Based on this composition, we studied its effect as a possible regenerative material for alveolar healing. Materials and Methods This study was conducted using four 2.5-year-old mongrel dogs (male; weight, 25 to 30 kg). The third mandibular premolars were carefully mobilized with a dental elevator and then removed using forceps. The crown portions of the extracted teeth were removed with cutters, and the root portions of the remaining teeth were collectively trimmed as closely as possible to 350 to 500 µm. Dentin and cementum (DC) chips harvested from the extracted teeth were soaked in blood and packed into the fresh sockets (autograft). Biopsies were performed at the ends of day 14 and day 56 following implantation. Data were expressed as mean±standard deviation and compared with t-test results. Results The ratio of SA(bone) to total area of each probe was determined and was 170±16 µm2 for the control group and 71±14 µm2 for the DC group, a significant difference (P<0.05). Conclusion DC particulate grafts offered no improvement in bone regeneration in alveolar extraction sockets. PMID:26131427

  16. Current Advance and Future Prospects of Tissue Engineering Approach to Dentin/Pulp Regenerative Therapy

    PubMed Central

    Gong, Ting; Heng, Boon Chin; Lo, Edward Chin Man; Zhang, Chengfei

    2016-01-01

    Recent advances in biomaterial science and tissue engineering technology have greatly spurred the development of regenerative endodontics. This has led to a paradigm shift in endodontic treatment from simply filling the root canal systems with biologically inert materials to restoring the infected dental pulp with functional replacement tissues. Currently, cell transplantation has gained increasing attention as a scientifically valid method for dentin-pulp complex regeneration. This multidisciplinary approach which involves the interplay of three key elements of tissue engineering—stem cells, scaffolds, and signaling molecules—has produced an impressive number of favorable outcomes in preclinical animal studies. Nevertheless, many practical hurdles need to be overcome prior to its application in clinical settings. Apart from the potential health risks of immunological rejection and pathogenic transmission, the lack of a well-established banking system for the isolation and storage of dental-derived stem cells is the most pressing issue that awaits resolution and the properties of supportive scaffold materials vary across different studies and remain inconsistent. This review critically examines the classic triad of tissue engineering utilized in current regenerative endodontics and summarizes the possible techniques developed for dentin/pulp regeneration. PMID:27069484

  17. Evaluation of metal bond strength to dentin and enamel using different adhesives and surface treatments.

    PubMed

    Dundar, Mine; Gungor, Mehmet Ali; Cal, Ebru; Darcan, Alev; Erdem, Adalet

    2007-01-01

    Because adherence of base metal alloys is important for the long-term clinical success of adhesive fixed partial dentures, it has been necessary to improve adhesion to metal substrate by using different surface treatments. This study used different surface conditioning methods and two different luting resins to evaluate the shear bond strength of base metal alloys to dentin and enamel. Sixty noncarious freshly extracted human teeth were mounted in a plastic holder filled with autopolymerized acrylic resin. After the roots were removed and 30 flat enamel and 30 flat dentin surfaces were exposed, the specimens were divided randomly into two main luting cement groups. Sixty nickel chromium (NiCr) metal specimens were fabricated and subjected to three different surface conditioning procedures: sandblasting with 50 microm aluminum oxide, tribochemical silica coating, and a combination of the two. Scanning electron mircoscopy (SEM) evaluations revealed mainly cohesive failures. Self-cure adhesive resulted in higher bond strengths to dental substrates. Higher bond strengths were achieved through a combination of sandblasting and tribochemical silica coating; however, further clinical research is required. A surface treatment that combines sandblasting with tribochemical silica coating can achieve a more effective bond for adhesive restorations with metal substrates. PMID:17511361

  18. Conventional versus digital approach for measuring dentin translucency in forensic age estimation

    PubMed Central

    Chopra, Varun; Thodasam, Gopal; Ahmad, Zeeshan Heera; Singh, Simranjit; Rajawat, Indresh; Gupta, Sonal

    2015-01-01

    Background: Root dentine translucency remains the method of choice providing the most accurate results for age estimation. Conventionally, translucency is measured using calipers. In recent times, computer-based methods are proposed, which require the use of custom-built software programs. Aims and Objectives: The aim was to use a digital method to measure dentinal translucency on sectioned teeth and to compare digital measurements to conventionally obtained translucency measurements. Materials and Methods: A total of 200 extracted permanent teeth were collected and were sectioned to a thickness of 250 μm. Translucency measurements were obtained using the digital method and compared with those obtained using a caliper. Results: Correlation coefficients of translucency measurements to age were statistically significant for both methods (P < 0.001), although marginally higher correlation was observed for the conventional method (r = 0.612). Application of derived linear regression equations on an independent sample (n = 25) suggested that conventional approach is marginally better in estimating age to within 5 years of the actual age, both the methods are similar in assessing age within 5-10 years of the actual age, and digital approach is marginally better in estimating age beyond 10 years of actual age. Conclusion: The translucency measurements obtained by the two methods were identical, with no clear superiority of one method over the other. PMID:25810651

  19. Analytical method to estimate resin cement diffusion into dentin

    NASA Astrophysics Data System (ADS)

    de Oliveira Ferraz, Larissa Cristina; Ubaldini, Adriana Lemos Mori; de Oliveira, Bruna Medeiros Bertol; Neto, Antonio Medina; Sato, Fracielle; Baesso, Mauro Luciano; Pascotto, Renata Corrêa

    2016-05-01

    This study analyzed the diffusion of two resin luting agents (resin cements) into dentin, with the aim of presenting an analytical method for estimating the thickness of the diffusion zone. Class V cavities were prepared in the buccal and lingual surfaces of molars (n=9). Indirect composite inlays were luted into the cavities with either a self-adhesive or a self-etch resin cement. The teeth were sectioned bucco-lingually and the cement-dentin interface was analyzed by using micro-Raman spectroscopy (MRS) and scanning electron microscopy. Evolution of peak intensities of the Raman bands, collected from the functional groups corresponding to the resin monomer (C–O–C, 1113 cm-1) present in the cements, and the mineral content (P–O, 961 cm-1) in dentin were sigmoid shaped functions. A Boltzmann function (BF) was then fitted to the peaks encountered at 1113 cm-1 to estimate the resin cement diffusion into dentin. The BF identified a resin cement-dentin diffusion zone of 1.8±0.4 μm for the self-adhesive cement and 2.5±0.3 μm for the self-etch cement. This analysis allowed the authors to estimate the diffusion of the resin cements into the dentin. Fitting the MRS data to the BF contributed to and is relevant for future studies of the adhesive interface.

  20. Methods for biomimetic remineralization of human dentine: a systematic review.

    PubMed

    Cao, Chris Ying; Mei, May Lei; Li, Quan-Li; Lo, Edward Chin Man; Chu, Chun Hung

    2015-01-01

    This study aimed to review the laboratory methods on biomimetic remineralization of demineralized human dentine. A systematic search of the publications in the PubMed, TRIP, and Web of Science databases was performed. Titles and abstracts of initially identified publications were screened. Clinical trials, reviews, non-English articles, resin-dentine interface studies, hybrid layer studies, hybrid scaffolds studies, and irrelevant studies were excluded. The remaining papers were retrieved with full texts. Manual screening was conducted on the bibliographies of remaining papers to identify relevant articles. A total of 716 studies were found, and 690 were excluded after initial screening. Two articles were identified from the bibliographies of the remaining papers. After retrieving the full text, 23 were included in this systematic review. Sixteen studies used analogues to mimic the functions of non-collagenous proteins in biomineralization of dentine, and four studies used bioactive materials to induce apatite formation on demineralized dentine surface. One study used zinc as a bioactive element, one study used polydopamine, and another study constructed an agarose hydrogel system for biomimetic mineralization of dentine. Many studies reported success in biomimetic mineralization of dentine, including the use of non-collagenous protein analogues, bioactive materials, or elements and agarose hydrogel system. PMID:25739078

  1. Dentin barrier test with transfected bovine pulp-derived cells.

    PubMed

    Schmalz, G; Schuster, U; Thonemann, B; Barth, M; Esterbauer, S

    2001-02-01

    Growth kinetics of SV40 large T-antigen-transfected bovine pulp-derived cells on dentin were investigated. These cells were used in a dentin barrier test device, and the system was evaluated by testing a set of dental filling materials. Cells (120 cells/mm2) were seeded on dentin slices and incubated for up to 21 days. Cell proliferation was recorded using MTT assay. For cytotoxicity tests 3500 cells/mm2 were seeded on dentin discs, which were then incorporated into the dentin barrier test device. After 72 h preincubation test materials were applied. After a 24 h exposure with or without perfusion of the pulpal part of the test device, cell survival was evaluated using MTT assay. The cells revealed similar growth kinetics on dentin slices and on tissue culture plates. In cytotoxicity tests the cells were more sensitive toward the test materials than previously used three-dimensional cultures of human foreskin fibroblasts and as anticipated from clinical experience. Further improvement is expected by using three-dimensional cultures of pulp-derived cells. PMID:11491647

  2. Methods for Biomimetic Remineralization of Human Dentine: A Systematic Review

    PubMed Central

    Cao, Chris Ying; Mei, May Lei; Li, Quan-Li; Lo, Edward Chin Man; Chu, Chun Hung

    2015-01-01

    This study aimed to review the laboratory methods on biomimetic remineralization of demineralized human dentine. A systematic search of the publications in the PubMed, TRIP, and Web of Science databases was performed. Titles and abstracts of initially identified publications were screened. Clinical trials, reviews, non-English articles, resin-dentine interface studies, hybrid layer studies, hybrid scaffolds studies, and irrelevant studies were excluded. The remaining papers were retrieved with full texts. Manual screening was conducted on the bibliographies of remaining papers to identify relevant articles. A total of 716 studies were found, and 690 were excluded after initial screening. Two articles were identified from the bibliographies of the remaining papers. After retrieving the full text, 23 were included in this systematic review. Sixteen studies used analogues to mimic the functions of non-collagenous proteins in biomineralization of dentine, and four studies used bioactive materials to induce apatite formation on demineralized dentine surface. One study used zinc as a bioactive element, one study used polydopamine, and another study constructed an agarose hydrogel system for biomimetic mineralization of dentine. Many studies reported success in biomimetic mineralization of dentine, including the use of non-collagenous protein analogues, bioactive materials, or elements and agarose hydrogel system. PMID:25739078

  3. Multiscale characterization of partially demineralized superficial and deep dentin surfaces.

    PubMed

    Pelin, Irina M; Trunfio-Sfarghiu, Ana-Maria; Farge, Pierre; Piednoir, Agnes; Pirat, Christophe; Ramos, Stella M M

    2013-08-01

    The objective of this study was to address the following question: 'Which properties are modified in partially demineralized surfaces, compared with non-demineralized dentin surfaces, following orthophosphoric acid-etching as performed in clinical procedures?'. For this purpose, the complementary techniques atomic force microscopy/spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and contact angle measurements were used to provide a multiscale characterization of the dentin substrate undergoing the acidic preconditioning designed to enhance wetting. Special attention was given to the influence of the etching pretreatment on the nanomechanical properties at different levels of dentin surfaces, in both dry and hydrated conditions. The four-sided pyramid model (extended Hertz contact model) proved to be accurate for calculating the apparent Young's modulus, offering new information on the elasticity of dentin. The modulus value notably decreased following etching and surface hydration. This study underlines that after the acid etching pretreatment the contribution of the nanomechanical, morphological, and physicochemical modifications has a strong influence on the dentin adhesion properties and thus plays a significant role in the coupling of the adhesive-resin composite build-up material at the dentin surface. PMID:23841786

  4. In vitro remineralization of severely compromised bonded dentin.

    PubMed

    Mai, S; Kim, Y K; Kim, J; Yiu, C K Y; Ling, J; Pashley, D H; Tay, F R

    2010-04-01

    Biomimetic remineralization is potentially useful for the remineralization of incompletely resin-infiltrated collagen matrices created by etch-and-rinse adhesives. In this study, we tested the hypothesis that structurally altered dentin collagen cannot be remineralized to the same hierarchical order and dimension seen in structurally intact dentin collagen. The remineralization medium consisted of a set Portland cement/simulated body fluid system containing polycarboxylic acid and polyvinylphosphonic acid as biomimetic analogs. Remineralization of air-dried, collapsed hybrid layers was apparent after one month, with hybrid layers remineralized to 80-90% of their thickness after 2-4 months. A hypermineralized layer was seen on the hybrid layer surface, and tubular orifices were occluded with apatite deposits that resembled those present in non-carious cervical dentin. Structurally altered collagen is unlikely to be remineralized to the same hierarchical order and dimension as seen in intact dentin. The aggressively air-dried acid-etched dentin remineralization model also sheds light on the mechanism of sclerotic dentin formation. PMID:20173183

  5. Selective removal of carious human dentin using a nanosecond pulsed laser operating at a wavelength of 5.85 μ m

    NASA Astrophysics Data System (ADS)

    Ishii, Katsunori; Kita, Tetsuya; Yoshikawa, Kazushi; Yasuo, Kenzo; Yamamoto, Kazuyo; Awazu, Kunio

    2015-05-01

    Less invasive methods for treating dental caries are strongly desired. However, conventional dental lasers do not always selectively remove caries or ensure good bonding to the composite resin. According to our previous study, demineralized dentin might be removed by a nanosecond pulsed laser operating at wavelengths of around 5.8 μm. The present study investigated the irradiation effect of the light on carious human dentin classified into "remove," "not remove," and "unclear" categories. Under 5.85-μm laser pulses, at average power densities of 30 W/cm2 and irradiation time of 2 s, the ablation depth of "remove" and "not remove," and also the ablation depth of "unclear" and "not remove," were significantly different (p<0.01). The ablation depth was correlated with both Vickers hardness and Ca content. Thus, a nanosecond pulsed laser operating at 5.85 μm proved an effective less-invasive caries treatment.

  6. The effects of host derived metalloproteinases on dentin bond and the role of MMPs inhibitors on dentin matrix degradation

    PubMed Central

    LONGHI, M.; CERRONI, L.; CONDÒ, S.G.; ARIANO, V.; PASQUANTONIO, G.

    2014-01-01

    SUMMARY Objectives. The work has the objective to analyze the literature on the degradation of the adhesive interface. In particular the study is focused on the role of the metalloproteinase in the hydrolytic degradation of collagen matrix in the bonded interface. The survey will concern also the latest innovations to improve and increase the link between dentin and the restorative materials through the MMPs inhibitors. Methods. The research has been carried out in the MEDLINE database by choosing keywords as “metalloproteinases” and “dentin bond” and “degradation”. In vitro studies were included in the research, excluding studies with no human and deciduous teeth. Language was limited to English. Results. The collagenolytic enzymes in mineralized dentin have been demonstrated to have an important role in dental hard tissue pathologies, including the degradation of the hybrid layer. Conclusion. The preservation of the collagen matrix integrity is a key issue in the attempts to improve the dentin bonding durability. PMID:25992261

  7. BOND STRENGTH OF RESIN MODIFIED GLASS IONOMER CEMENT TO PRIMARY DENTIN AFTER CUTTING WITH DIFFERENT BUR TYPES AND DENTIN CONDITIONING

    PubMed Central

    Nicoló, Rebeca Di; Shintome, Luciana Keiko; Myaki, Silvio Issáo; Nagayassu, Marcos Paulo

    2007-01-01

    The aim of this in vitro study was to evaluate the effect of different bur types and acid etching protocols on the shear bond strength (SBS) of a resin modified glass ionomer cement (RM-GIC) to primary dentin. Forty-eight clinically sound human primary molars were selected and randomly assigned to four groups (n=12). In G1, the lingual surface of the teeth was cut with a carbide bur until a 2.0-mm-diameter dentin area was exposed, followed by the application of RM-GIC (Vitremer – 3M/ESPE) prepared according to the manufacturer’s instructions. The specimens of G2, received the same treatment of G1, however the dentin was conditioned with phosphoric acid. In groups G3 and G4 the same procedures of G1 and G2 were conducted respectively, nevertheless dentin cutting was made with a diamond bur. The specimens were stored in distilled water at 37°C for 24h, and then tested in a universal testing machine. SBS. data were submitted to 2-way ANOVA (= 5%) and indicated that SBS values of RM-GIC bonded to primary dentin cut with different burs were not statistically different, but the specimens that were conditioned with phosphoric acid presented SBS values significantly higher that those without conditioning. To observe micromorphologic characteristics of the effects of dentin surface cut by diamond or carbide rotary instruments and conditioners treatment, some specimens were examined by scanning electron microscopy. Smear layer was present in all specimens regardless of the type of rotary instrument used for dentin cutting, and specimens etched with phosphoric acid presented more effective removal of smear layer. It was concluded that SBS of a RM-GIC to primary dentin was affected by the acid conditioning but the bur type had no influence. PMID:19089179

  8. Evaluation of the Bond Strength of Resin Cements Used to Lute Ceramics on Laser-Etched Dentin

    PubMed Central

    Duzdar, Lale; Oksuz, Mustafa; Tanboga, Ilknur

    2014-01-01

    Abstract Objective: The purpose of this study was to investigate the shear bond strength (SBS) of two different adhesive resin cements used to lute ceramics on laser-etched dentin. Background data: Erbium, chromium: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) laser irradiation has been claimed to improve the adhesive properties of dentin, but results to date have been controversial, and its compatibility with existing adhesive resin cements has not been conclusively determined. Materials and methods: Two adhesive cements, one “etch-and-rinse” [Variolink II (V)] and one “self-etch” [Clearfil Esthetic Cement (C)] luting cement, were used to lute ceramic blocks (Vita Celay Blanks, Vita) onto dentin surfaces. In total, 80 dentin specimens were distributed randomly into eight experimental groups according to the dentin surface-etching technique used Er,Cr:YSGG laser and Er:YAG laser: (1) 37% orthophosphoric acid+V (control group), (2) Er,Cr:YSGG laser+V, (3) Er,Cr:YSGG laser+acid+V, (4) Er:YAG laser+V, (5) Er:YAG laser+acid+V, (6) C, (7) Er,Cr:YSGG laser+C, and (8) Er:YAG laser+C. Following these applications, the ceramic discs were bonded to prepared surfaces and were shear loaded in a universal testing machine until fracture. SBS was recorded for each group in MPa. Shear test values were evaluated statistically us