Effect of phytic acid on bond strength and interfacial integrity of universal adhesive to deep dentin

Abstract This study investigated the effect of phytic acid (IP6) in different concentrations and application times on microtensile bond strength (µTBS) and interfacial integrity of universal adhesive to deep dentin. Flat deep dentin surfaces of 48 human molars were either etched with 37% phosphoric acid (PA) for 15 sec (control); or received no acid treatment and universal adhesive was applied directly in a self-etch mode (SE); or divided according to IP6 concentration (C) into two main groups: C1, 0.5%, and C2, 1%. Specimens of IP6 groups were further subdivided into three subgroups according to application time of IP6 (T) where; T1, 15 sec; T2, 30 sec and T3, 60 sec. Single Bond Universal Adhesive was then applied and resin composite blocks were built-up. Forty Specimens were then sectioned to produce resin/dentin beams that were used for µTBS testing using a universal testing machine. The remaining eight specimens were sectioned into slabs that were immersed into ammonical silver nitrate solution and nanoleakage was observed using a field emission scanning electron microscope (FE-SEM). The results showed that the application of IP6 in 0.5% and 1% produced significantly higher µTBS and less nanoleakage compared to PA and SE groups. Also, the application of IP6 for 60 sec recorded the highest µTBS and the lowest nanoleakage followed by 30 sec, and 15 sec respectively. Therefore, conditioning of deep dentin with IP6 enhances µTBS and interfacial integrity of universal adhesive to deep dentin in comparison to PA etching or using the universal adhesive in SE mode.

Resumo Este estudo investigou o efeito do ácido fítico (IP6) em diferentes concentrações e tempos de aplicação na resistência da ligação microtensiva (µTBS) e na integridade interfacial do adesivo universal à dentina profunda. As superfícies planas de dentina profunda de 48 molares humanos foram preparadas com ácido fosfórico (PA) a 37% durante 15 seg. (controlo); ou não receberam tratamento ácido e o adesivo universal foi aplicado diretamente em modo de auto-adesivo (SE); ou dividido de acordo com a concentração de IP6 (C) em dois grupos principais: C1, 0,5%, e C2, 1%. Os espécimes dos grupos IP6 foram ainda subdivididos em três subgrupos de acordo com o tempo de aplicação do IP6 (T) em que; T1, 15 seg; T2, 30 seg e T3, 60 seg. Aplicou-se então Single Bond Universal Adhesive e construíram-se blocos compostos de resina. Quarenta espécimes foram então seccionados para produzir feixes de resina/dentina que foram usados para testes µTBS usando uma máquina de testes universal. Os restantes oito espécimes foram seccionados em placas que foram imersas em solução amoniacal de nitrato de prata e observou-se uma nano-infiltração utilizando um microscópio eletrônico de varrimento de emissões de campo (FE-SEM). Os resultados mostraram que a aplicação de IP6 em 0,5% e 1% produziu µTBS significativamente mais elevado e menos nano-infiltração em comparação com os grupos PA e SE. Além disso, a aplicação de IP6 durante 60 seg registou o µTBS mais alto e o mais baixo de nano-infiltração seguido de 30 seg, e 15 seg respectivamente. Portanto, o condicionamento da dentina profunda com IP6 melhora o µTBS e a integridade interfacial do adesivo universal à dentina profunda em comparação com a gravação de PA ou utilizando o adesivo universal no modo SE.

Deep dentine caries management of immature permanent posterior teeth with vital pulp: A systematic review and meta-analysis.

OBJECTIVES: Preservation of pulpal vitality in immature permanent teeth with deep carious lesions is essential to enable further root development and apical closure. This systematic review aimed to evaluate the evidence regarding the efficacy, presented clinical and radiographic success, and bacteriological outcomes of techniques and materials used for deep caries management in vital immature permanent teeth. DATA: Randomised controlled trials evaluating Vital Pulp Therapy (VPT) for deep caries in immature permanent posterior teeth without history of irreversible pulpitis, and a follow up period of ≥12 months were included. Study characteristics and outcomes of all included studies were summarized. Cochrane's Risk-of-bias tool 2.0 was used to assess the quality of eligible studies. Meta-analyses using a random effects model was performed. SOURCES: Electronic databases PubMed, Medline, Embase, LILACS, CENTRAL and Cochrane Library were searched, followed by a manual search. STUDY SELECTION: Twelve papers were included into the review. Overall success rates were 98%, 93.5%, 93.6% for direct pulp cap (DPC), indirect pulp cap (IPC) and pulpotomy (PP) respectively. Regardless of VPT technique, there were no significant differences between clinical and radiographic success rates. Completion of root development was achieved in more than 83% of the cases in all VPT techniques. CONCLUSIONS: All treatment modalities for PP were equally efficient with high overall success rates. Biodentine showed high success rates regardless of technique. No significant differences were found in the clinical and radiographic success rates between various follow-up intervals. There are no clear conclusions regarding superiority of either VPT technique on apical closure. CLINICAL SIGNIFICANCE: This manuscript systematically evaluates the evidence and summarises all available data on each vital pulp therapy technique and materials used in treatment of deep caries in immature permanent teeth with vital pulps. The limitations in the current scientific literature and recommendations for future research are also highlighted.

Children's dental treatment requirements of first permanent molars with poor prognosis.

OBJECTIVES: This retrospective study aimed to (i) survey the correlation between decayed, missing, filled teeth (DMFT), and presence of first permanent molars (FPMs) with poor prognosis and (ii) evaluate the treatment requirements. MATERIALS AND METHODS: Seven hundred seventy-three children with fully erupted FPMs were included in this study. DMFT for the permanent dentition, FPMs, and Global DMFT were evaluated based on clinical and radiographic evaluation. The ratio of deep dentin caries (DDC) and apical lesion presence among FPMs, including treatment requirements, were analysed. Spearman rank correlation coefficient and t tests were used for statistical analysis. RESULTS: The caries prevalence was found at 61.4%, where the mean DMFT was calculated as 1.89 ± 2.15. There was a positive correlation between DMFT values and age (rs = 0.27). On the other hand, there was a negative correlation between global DMFT values and age (rs = - 0.29). Regarding treatment needs of FPM with poor prognosis, 12.03% of the teeth needed pulpectomy, 8.93% pulpotomy, 8.93% pulp capping, and 5.3% extraction. Having higher DMFT values was correlated significantly (p < 0.01) with the presence of DDC (rs = 0.50) and apical lesion (rs = 0.34). Susceptibility to DDC and apical lesions was significantly higher at mandible than maxilla (p < 0.01). The correlation was significant between DMFT values and apical lesion presence (p < 0.01). CONCLUSION: The ratio of FPMs with poor prognosis was found high in the study group. Treatment requirements of FPMs increased with age, and pulp interventions often took part in the majority. This study successfully concluded that higher DMFT values were correlated with the presence of DDC and apical lesion. CLINICAL RELEVANCE: FPMs with poor prognosis demonstrate a risk factor for apical lesion presence.

Effect of proanthocyanidin and riboflavin on shear bond strength of a nanocomposite to deep dentin - An in vitro Study.

Aims: The objective of this study was to evaluate the effect of two collagen crosslinking agents on shear bond strength of a nanocomposite using total-etch adhesive to deep dentin. Materials and Methods: Thirty maxillary central incisors were selected for the study and each tooth was divided into two equal halves with diamond disc (n = 60). Proximal surfaces were prepared to expose the deep dentin until the remaining dentin thickness was approximately 1 mm. The specimens were divided into three groups based upon the biomodification of dentin with collagen crosslinking agents. In Group I (n = 20), no collagen crosslinking agent was used before bonding system. In Group II, deep dentin biomodification was done with 6.5% proanthocyanidin (PA). In Group III, deep dentin biomodification was done with Riboflavin. Shear bond strength was evaluated using universal testing machine. Statistical Analysis Used: One-way analysis (ANNOVA). Pairwise comparison of groups was done with post hoc test. Results: Biomodification of deep dentin with PA showed the highest shear bond strength followed by riboflavin and control group. Conclusion: Biomodification of dentin surface with collagen cross-linking agents results in improvement of bond strength of total-etch adhesive to deep dentin.

Effect of chitosan treatment on shear bond strength of composite to deep dentin using self-etch and total-etch adhesive systems / Efeito do tratamento com quitosana na resistência ao cisalhamento de resina compost em dentina profunda usando sistemas adesivos autocondicionantes e condicionamento total

Objective: To assess the shear bond strength (SBS) of resin composite to deep dentin, using 1 and 2.5% chitosan pretreatment as well as different adhesive systems. Material and Methods: 80 human maxillary molars were randomly divided to eight groups according to the type of adhesive system and dentin pretreatment (n = 10): I) two-step self-etch system (Clearfil SE bond); II) two-step etch-and-rinse system (Adper single bond 2); III) 2.5% chitosan + Clearfil SE bond; IV) 2.5% chitosan +etch + Adper single bond 2; V) etch + 2.5% chitosan + Adper single bond 2; VI) 1% chitosan + Clearfil SE bond; VII) 1% chitosan + etch + Adper single bond 2; VIII) etch + 1% chitosan + Adper single bond 2 (chitosan solution (w/v): 2.5 g and 1 g of chitosan (Sigma Aldrich, USA) was dissolved in 100 ml of 1% acetic acid). Plastic molds were positioned on dentin and filled with composite (Z350, 3M ESPE, USA). SBS (MPa) was tested using a universal testing machine. ANOVA tests, Tukey's test, and independent t test were used to analyze data (p ≤ 0.05). Results: The highest SBS value among self-etch groups was observed with 1% chitosan (p = 0.001). In the etch-and-rinse group, the SBS of 1% chitosan was significantly lower than the other groups. Chitosan treatment following acid etching led to higher SBS in comparison to when chitosan was applied before etching, with the significant difference in 1% concentration (p = 0.030). A predominance of mix fractures was observed in dentin. Conclusion: Improved dentin bond strength can be achieved through immediate dentin pretreatment with 1% chitosan in self-etch adhesive systems. Chitosan Pretreatment may not be advantageous for etch-and-rinse adhesive systems. (AU)

Objetivo: Avaliar a resistência ao cisalhamento (RC) da resina composta em dentina profunda, utilizando quitosana de 1 e 2,5% como pré-tratamento, e também diferentes sistemas adesivos. Materiai e métodos: 80 molares superiores humanos foram divididos aleatoriamente em oito grupos de acordo com o tipo de sistema adesivo e pré-tratamento dentinário (n = 10): I) sistema autocondicionante de dois passos (Clearfil SE bond); II) sistema convencional de dois passos (Adper Single Bond II); III) quitosana 2,5% + Clearfil SE bond; IV) quitosana 2,5% + ácido + Adper single bond; V) ácido + quitosana 2,5% + Adper single bond II; VI) quitosana 1% + Clearfil SE bond; VII) quitosana 1% + ácido + Adper single bond II; VIII) ácido + quitosana 1% + Adper single bond II (solução de quitosana (w/w): 2,5 ge 1 g de quitosana (Sigma Aldrich, EUA) foi dissolvido em 100 ml de ácido acético a 1%). Moldeiras foram posicionados na dentina e preenchidos com resina composta (Z350, 3M ESPE, EUA). O RC (MPa) foi testado em uma máquina de teste universal. Os testes ANOVA, teste de Tukey e teste t foram usados para analisar os dados (p ≤ 0,05). Resultados: O maior valor de RC entre os grupos autocondicionantes foi observado com quitosana a 1% (p = 0,001). No grupo do condicionamento total a RC da quitosana a 1% foi significativamente menor do que nos outros grupos. O tratamento com quitosana após o condicionamento ácido levou a um maior RC em comparação a quitosana aplicada antes do condicionamento, com diferença significativa na concentração de 1% (P = 0,030). Observou-se predomínio de fraturas na dentina. Conclusão: A resistência de união à dentina pode ser alcançada por meio do pré-tratamento imediato da dentina com quitosana a 1% em sistemas adesivos autocondicionantes. O pré-tratamento com quitosana pode não ser vantajoso para sistemas adesivos de condicionamento total. (AU)

Long-term survival of different deep dentin caries treatments: A 5-year clinical study.

OBJECTIVE: The aim of this in-vivo study was to evaluate the long-term clinical survival of different deep dentin caries treatment options. MATERIALS AND METHODS: : In total, 391 patients with at least one permanent tooth with clinically diagnosed deep dentin caries were inspected. Two hundred and fourteen patients were examined at recall visits. Inclusion criteria were teeth with deep caries lesions with pulp vitality but absence of spontaneous pain and periapical alterations. The subjects received either stepwise removal (SWR), complete caries removal (CCR), or direct pulp capping (DPC). The radiological and clinical exams were performed after a mean observation time of 62 months. Success was defined as pulp sensitivity to vitality test and absence of periapical lesions as well as a clinical symptom. Data were statistically analyzed using Kaplan-Meier and log-rank (Mantel-Cox) tests (α = 0.05). RESULTS: Of the total 214 patients evaluated, 126 received SWR, 88 received CCR, and 67 received DPC treatment. One hundred and twenty-seven restorations were amalgam and 141 were composite. The mean observation period was 62 months. Survival rates were 85.7%, 90.9%, and 59.7% for SWR, CCR, and DPC, respectively (P = 0.001). Success rates of amalgam restorations (86.6%) were similar to composite restorations (83%), and both were found to be successful (P = 0.401). CONCLUSION: SWR treatment should be considered to preserve pulp vitality of deep dentin lesions instead of CCR or DPC. CLINICAL RELEVANCE: SWR method for deep dentin caries management had acceptable results over 5 years.

Visualization of the pulp chamber roof and residual dentin thickness by spectral-domain optical coherence tomography in vitro.

The aim of this study was to evaluate the ability of spectral-domain optical coherence tomography (SD-OCT) to display the roof of the pulp chamber and to estimate the residual dentin thickness (RDT) of the pulp complex. The roots of 20 extracted human molars were embedded in epoxy resin, and crowns were longitudinally sectioned in the mesial-distal direction, exposing the pulp chamber. The coronal part of the crown was removed up to an RDT to the pulp chamber roof of 2 mm. Samples were imaged by SD-OCT from coronal view and by light microscopy (LM) in the sagittal plane. Using a microtome, dentin was subsequently removed in four levels from the occlusal aspect in steps of 250 µm. At each level, RDT was documented and measured by both methods. The data were compared (Spearman's rho correlation coefficient, Wilcoxon signed-rank test). Using OCT, the roof of the pulp chamber was first displayed at a maximum RDT of 1.94 mm. The minimal RDT that could be imaged by OCT was 0.06 mm. Values from both methods were strongly correlated (r, 0.83-0.95; pi ≤ 0.05) and differed significantly for large RDTs (dentin levels 1, 2; pi < 0.05) but not for small RDTs (levels 3, 4; pi ≥ 0.226). The roof of the dental pulp chamber could be already visualized by SD-OCT with a RDT of 1.94 mm. Therefore, the method could be a useful diagnostic tool during the preparation of deep dentin cavities and might help to preserve the integrity of the pulp chamber.

Effect of Dimethyl Sulfoxide on Bond Strength of a Self-Etch Primer and an Etch and Rinse Adhesive to Surface and Deep Dentin.

STATEMENT OF THE PROBLEM: Composite bond to dentin is crucial in many clinical conditions particularly in deep cavities without enamel margins due to insufficient penetration of adhesive into demineralized dentin. PURPOSE: The aim of this study was to assess the shear bond strength (SBS) of a methacrylate-based and a silorane-based composite resin to surface and deep dentin after pretreatment with dimethyl sulfoxide (DMSO). MATERIALS AND METHOD: Eighty extracted human premolars were randomly divided into two groups of flat occlusal dentin with different cuts as A: surface group (sections just below the dentinoenamel junction (DEJ) and B: deep group (2 mm below DEJ). Each group was randomly assigned to 4 subgroups and their samples were restored with Adper Single bond (ASB) and Filtek Z350 or Silorane system Adhesive (SA) and Filtek P90 composite resins, using a 3×3mm cylindrical plastic mold. following these steps , the subgroups were assigned as SubgroupA1: surface dentin+ Silorane System Primer (SSP)+ Silorane System Bonding (SSB)+ P90; Subgroup A2: surface dentin+ 37% etchant (E37%) + Adper Single Bond (ASB)+ Z350; Subgroup A3: surface dentin+ DMSO+ SSP+ SSB+ P90; Subgroup A4: surface dentin+ E37%+ DMSO+ ASB+ Z350; Subgroup B1: deep dentin+ SSP+ SSB+ P90; Subgroup B2: deep dentin+ E37%+ ASB+ Z350; Subgroup B3: deep dentin+ DMSO+ SSP+ SSB+ P90; Subgroup B4:dentin +E37% +DMSO +ASB +Z350. The specimens were thermocycled at 5± 2/55± 2°C for 1000 cycles and then tested for SBS. RESULTS: Using DMSO as dentin conditioner increased SBS of ASB to deep dentin (p< 0.001) and SBS of SA to surface dentin (p= 0.003) but had no effect on SBS of SA to deep dentin (p= 1.00). CONCLUSION: The ability of DMSO to increase SBS of ASB to deep dentin provides a basis for improving bonding of this composite resin in deep cavities.

Resin luting materials: Tissue response in dog's teeth.

The aim of this study was to evaluate radiographically and histologically the pulpal and periapical response to self-adhesive (Rely X™ Unicem) and self-etching and self-curing (Multilink(®)) resin-based luting materials in deep cavities in dogs' teeth. Deep class V cavities (0.5-mm-thick dentin) were prepared in 60 canine premolars and the following materials were applied on cavity floor: Groups I/V-RelyX™ Unicem; Groups II/VI-Multilink(®); Groups III/VII-zinc phosphate cement (control) and; Groups IV/VIII-gutta-percha (control). Cavities were restored with silver amalgam. Animals were euthanized after 10 days (groups I-IV) and 90 days (groups V-VIII). Tooth/bone blocks were radiographed and processed for histopathological evaluation of pulp and periapical tissue response to the materials. All materials presented similar histopathological features and radiographic findings at both periods. The pulp tissue was intact. The apical and periapical regions and periodontal ligament thickness were normal. No inflammatory cells, resorption of mineralized tissue (dentin, cementum, and alveolar bone) or bacteria were observed. The lamina dura was intact and no areas of periapical bone rarefaction or internal/external root resorption were observed radiographically. It can be concluded that Rely X™ Unicem and Multilink(®) caused no adverse tissue reactions and may be indicated for cementation of indirect restorations in deep dentin cavities without pulp exposure.

Evaluation of Shear Bond Strength of Newer Bonding Systems on Superficial and Deep Dentin.

BACKGROUND: The purpose of this study was to compare the shear bond strength of nanocomposite resin to superficial dentin and deep dentin using two different dentin bonding systems. MATERIALS AND METHODS: All teeth were sectioned at various levels (superficial dentin: Dentin within 0.5-1 mm of dentinoenamel junction; deep dentin: Dentin within 0.5 mm of the highest pulp horn) using a Carborundum Disc and embedded in acrylic block of specific size. Selected specimens (60 premolar teeth) were grouped randomly into three groups, the groups were differentiated into superficial dentin, deep dentin, and control group which were further divided into sub Group A and Subgroup B containing 10 teeth each, depending on the bonding agents used. In Subgroup A, Tetric N Bond, and in Subgroup B Single Bond Universal were used. In the control group no bonding agent was used. The specimens were thermocycled for 500 cycles between 5°C and 55°C water bath for 40 s. Finally, the specimens were subjected to shear bond strength study under INSTRON machine (Universal Testing Machine). The maximum shear bond strengths were noted at the time of fracture (de-bonding) of the restorative material. Results were analyzed using ANOVA test, Bonferroni test, and paired t-test. RESULTS: Bond strength values of fifth generation bonding system (Tetric N Bond) showed higher mean shear bond strength compared to seventh generation bonding system (Single Bond Universal). There was a significant fall in bond strength values as one reaches deeper levels of dentin from superficial to deep dentin. CONCLUSION: There was a significant difference between the bond strength of fifth generation bonding system (Tetric N Bond) and seventh generation bonding system (Single Bond Universal). Decrease in the bond strength values is seen for the deeper level of dentin as compared to superficial dentin.

Validation of Optical Coherence Tomography against Micro-computed Tomography for Evaluation of Remaining Coronal Dentin Thickness.

INTRODUCTION: Optical coherence tomography (OCT) is a noninvasive modality to obtain in-depth images of biological structures. A dental OCT system has become available for chairside application. This in vitro study hypothesized that swept-source OCT can be used to measure the remaining dentin thickness (RDT) at the roof of the dental pulp chamber during excavation of deep caries. METHODS: Human molar teeth with deep occlusal caries were investigated. After obtaining 2-dimensional and 3-dimensional OCT scans using a swept-source OCT system at a 1330-nm center wavelength, RDT was evaluated by image analysis software. Microfocus x-ray computed tomographic (micro-CT) images were obtained from the same cross sections to confirm OCT findings. The smallest RDT values at the visible pulp horn were measured on OCT and micro-CT imaging and compared using the Pearson correlation. Pulpal horns and pulp chamber roof observation under OCT and micro-CT imaging resulted in comparable images that allowed the measurement of coronal dentin thickness. RESULTS: RDT measured by OCT showed optical values range between 140 and 2300 µm, which corresponded to the range of 92-1524 µm on micro-CT imaging. A strong correlation was found between the 2 techniques (r = 0.96, P < .001). CONCLUSIONS: Further analysis indicated linear regression with a slope of 1.54 and no intercept, closely matching the bulk refractive index of dentin. OCT enables visualization of anatomic structures during deep caries excavation. Exposure of the vital dental pulp because of the removal of very thin remaining coronal dentin can be avoided with this novel noninvasive technique.

Multiscale characterization of partially demineralized superficial and deep dentin surfaces.

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.

Effect of collagen cross-linkers on the shear bond strength of a self-etch adhesive system to deep dentin.

OBJECTIVES: To evaluate the shear bond strength of composite resin to deep dentin, bonded using a self-etch adhesive, after treatment with two collagen cross-linkers at varying time intervals. MATERIALS AND METHODS: Thirty extracted human incisors were sectioned longitudinally into equal mesial and distal halves (n = 60). The proximal deep dentin was exposed and the specimens were divided based on the surface treatment of dentin prior to bonding as follows: Group I (n = 12, control): No prior dentin surface treatment; group II (n = 24): Dentin surface pretreated with 10% sodium ascorbate; and group III (n = 24): Dentin surface pretreated with 6.5% proanthocyanidin. Groups II and III were further divided into two subgroups based on the pre-treatment time of five and 10 min. Shear bond strength of the specimens was tested using universal testing machine and the data were statistically analyzed. RESULTS: Significantly higher shear bond strength to deep dentin was observed in teeth treated with 10% sodium ascorbate and 6.5% proanthocyanidin compared to control group. No significant difference was observed between 5 min and 10 min pre-treatment times. CONCLUSION: Dentin surface pre-treatment with both 10% sodium ascorbate and 6.5% proanthocyanidin resulted in significant improvement in bond strength of self-etch adhesive to deep dentin.

The effect of concentration and application time of hydrogen peroxide on the microtensile bond strength of resin restorations to the dentin at different depths / 대한치과보존학회지

The purpose of this study was to examine the effect of hydrogen peroxide at different application time and concentrations on the microtensile bond strength of resin restorations to the deep and the pulp chamber dentin. A conventional endodontic access cavity was prepared in each tooth, and then the teeth were randomly divided into 1 control group and 4 experimental groups as follows: Group 1, non treated; Group 2, with 20% Hydrogen peroxide(H2O2); Group 3, with 10% H2O2; Group 4, with 5% H2O2; Group 5, with 2.5% H2O2; the teeth of all groups except group 1 were treated for 20, 10, and 5min. The treated teeth were filled using a Superbond C&B (Sun medical Co., Shiga, Japan). Thereafter, the specimens were stored in distilled water at 37degrees C for 24-hours and then sectioned into the deep and the chamber dentin. The microtensile bond strength values of each group were analyzed by 3-way ANOVA and Tukey post hoc test(p 0.05). The higher H2O2 concentration, the more opened dentinal tubules under a scanning electron microscope(SEM) examination.

Comparative bond strength of single step adhesives to different dentinal depths / 대한치과보존학회지

This study compared the microtensile bond strength (microTBS) of single step adhesives to different dentin depths. Superficial or deep dentin was exposed in 30 molar teeth by sectioning immediately under the DEJ or 1.5 mm area from central pit, respectively. After polishing with 600-grit SiC paper, the dentin surfaces were assigned to three groups: AQ group-AQ Bond, L-Pop group-Adper Prompt L-Pop, Xeno group-Xeno III. The bonded specimens were sectioned into sticks and subjected to microTBS testing with a crosshead speed of 1 mm/minute. The results of this study were as follows; The microTBS to superficial dentin was higher than that to deep dentin in all group. The microTBS of Xeno group was significantly higher than that of L-Pop group and AQ group in both superficial and deep dentin (p < 0.05).