Introduction: This study was conducted to evaluate and compare the effect of using three adhesive systems on the shear bond strength between composite resin and fresh amalgam. Materials and Methods: Amalgam samples were assigned into three groups according to the adhesive systems being used prior to the composite resin application. Group A (n = 10): universal self-etch bonding system (Single Bond Universal Adhesive, 3M, Neuss, Germany) was applied and light cured. Group B (n = 10): universal self-etch bonding was applied and light cured, followed by a thin layer of nanohybrid flowable composite (Tetric N-Flow, Ivoclar Vivadent, Liechtenstein), then light cured. Group C (n = 10): self-adhesive dual-cure luting resin cement (Calibra Universal, Dentsply Sirona, Charlotte, NC) was applied in equal quantity for each sample over amalgam surface. Composite resin was then applied by plastic instrument in a single increment to the height of the hole (2 mm), then celluloid strip was placed and light cured. After thermocycling, a shear bond test was performed. Results: Resin luting cement interface showed the higher significant bond strength, followed by universal bonding agent − flowable composite interface. The universal bonding interface group yielded the lowest results. Conclusion: The application of self-adhesive dual-cure luting resin cement resulted in significant increase in bond strength between composite resin and fresh amalgam.

Introduction: We aimed to determine how the various adhesive systems affect the shear bond strength (SBS) to normal and artificially create caries affected dentin (CAD) in permanent teeth. Methods: Forty eight sound premolars had their occlusal enamel ground to create flattened midcoronal dentin. According to the dentin substrate, specimens were allocated into sound and artificially created CAD induction using the pH-cycling technique. Each group was further subdivided according to the adhesive materials: Scotchbond Universal Plus, Scotchbond Universal, and Adper Single Bond 2 adhesives (applied in Etch and Rinse Adhesive Protocol). After that, a composite was put on and shear bond strength (SBS) tests were done. Data analyzed using two-way ANOVA and chi-squared tests. Results: Overall model test of the ANOVA statistics showed that both type of dentin and types of adhesive had a significant effect on the SBS values (P <  0.001). Tuckey post hoc comparisons showed a significant difference for type of dentin (P <  0.001) and types of adhesive (P ≤  0.005). Mode of failure assessment is non-statistically significant difference (P = 0.41). Conclusion: All adhesives showed a decrease in SBS when used on artificial CAD.

Introduction: GuttaFlow Bioseal (Roeko–Coltene/Whaledent, Langenau, Germany), TotalFill Bioceramic (FKG Dentaire SA, La Chaux-de-Fonds, Switzerland), and AH Plus root canal sealers (Dentsply, DeTrey, Germany) are used to prevent communication between periapical space and the root canal. This study aims to evaluate the apical microleakage of three endodontic sealers. Materials and Methods: Seventy-five freshly extracted mandibular premolars were prepared and obturated with single-cone gutta-percha, then grouped into three groups according to the sealers used. The data were analyzed using one-way analysis of variance (ANOVA) and Tukey honestly significant difference (HSD) test. Results: The least mean dye penetration was shown by GuttaFlow Bioseal sealer (1.31 mm), followed by TotalFill Bioceramic sealer (1.57 mm) and AH Plus sealer (2.63 mm); no dye penetration was found in the negative control group. One-way analysis of variance (ANOVA) showed statistically significant difference among all experimental groups (P < 0.001); Tukey test shows significant differences between all groups except for a nonsignificant difference between GuttaFlow Bioseal and TotalFill Bioceramic sealer (P = 0.6). Conclusion: All sealers showed varying levels of apical microleakage, with the least penetration in the GuttaFlow Bioseal group.