The purposes of the study were to evaluate the influence of the sealer’s chemical composition on the interfacial strength between root canal dentin and root filling material, for two different classes of endodontic sealers, and to assess their failure modes. Methods: Forty extracted single-rooted teeth were randomly divided into four groups using the following endodontic sealers: RealSeal SE and Resilon (RSSE); EndoSequence BC sealer and BC Point (EBCS); Endoseal MTA and gutta-percha (EDS); Bioroot RCS and gutta-percha (BRS). Teeth were embedded in acrylic resin, and the roots were sectioned horizontally into 1 mm slices. For each slice, the perimeter was measured. A push-out test was performed using an Instron universal testing machine. For each sample, bond strength was calculated. Specimens were examined by SEM investigation in order to analyze the dentin–sealer–core interface. Results were assessed using analysis of variance (ANOVA) and Tukey and Bonferroni test. Results: Statistical analysis revealed that EDS and gutta-percha had significantly higher resistance to dislodgement compared to the other three groups (p < 0.05). EBCS and BC Point showed significantly greater push-out bond strength values compared to RSSE and Resilon (p < 0.05). Conclusions: Bioceramic endodontic sealers showed a higher bond strength to root dentin than methacrylate resin-based endodontic sealer.

Background and Objectives: The aim of this study was to compare the accuracy of three types of electronic apex locators (EALs) when two different concentrations of NaOCl irrigation solutions are used by two operators. Materials and Methods: After creating the access cavities for 20 single rooted extracted teeth, the actual canal length (ACL) of each canal was determined visually using a #10 file and magnification. The teeth were subsequently inserted in plastic molds filled with alginate. The electronic measurement of root canal length (EWL) was performed using three different electronic apex locators: Root ZX II, Apex ID, and Dual Pex. Two independent operators, an endodontic specialist with 20 years practice and an undergraduate student in the final year of study, performed the irrigation procedures with two different concentrations of NaOCl (2% and 5.25%), and then measured the EWL using each of the EALs. The accuracy of all EALs, was determined in each case by subtracting the EWL from the ACL. Statistical analyses were performed using one-way ANOVA test. Results: In the presence of 2% NaOCl solution, for a margin error of ±0.5 mm, Root ZX II, Apex ID, and Dual Pex presented an accuracy of 90%, 80%, and 85% respectively. The increase in the concentration of the irrigation solution affected the accuracy of Root ZX II and Apex ID for both operators, diminishing it to 75% for the same margin error, but improved Dual Pex’s accuracy to 100%. Conclusions: The best accuracy in working length determination was obtained by Root ZX II for 2% NaOCl solution and by Dual Pex for 5.25% NaOCl solution with no significant statistical difference when compared.

This study evaluates and compares by dye penetration method and SEM photomicrographs the sealing obtained using two different classes of adhesive systems (etch-and-rinse and self-etch with selective etching) with SDR (Dentsply) bulk fill composite. 84 class V cavities were prepared on oral and vestibular face of 42 intact, freshly extracted wisdom teeth. The cavities were randomly divided in two groups and restored: Group 1 with prime &bond one select (Dentsply) and SDR (Dentsply) and Group 2 with prime&bond one Etch&Rinse (Dentsply) and SDR (Dentsply). Prime&bond one Select (Dentsply) is a single component adhesive and can be used in self etch mode, in selective enamel etch mode, or in etch-and-rinse mode. We chosen for this study the selective etch of the enamel mode. Prime&bond one Etch Rinse (Dentsply) is a universal etch-and-rinse one-bottle dental adhesive, designed to be used in two steps. The bulk fill composites are commonly used in modern dentistry due to their properties of low polymerization shrinkage and curing in layer of 4 mm depth, offering the practitioner a fast clinical procedure with good results. The results showed a good sealing at enamel and dentin margins with no statistically significant difference between adhesives, even though the mean of enamel infiltration was smaller for Group1. Furthermore the results show that there were differences between the two groups, for the infiltrations at the enamel, the values of microleakage being arithmetically higher for Group 1, but with no statistically difference between the two groups.SEM images showed for both groups a good adhesion surface with the tooth, but the hybrid layer of the total-etch adhesives is different from the hybrid layer formed by self etch adhesives, in terms of thickness, uniformity. In conclusion both adhesive systems have equivalent sealing qualities and can be successfully used with SDR.