Pulpal responses after application of current adhesive systems to deep cavities

The aim of the present study was to evaluate comparatively the pulpal tissue reactions of four adhesive systems placed in experimental cavities of healthy dog's teeth. Class V cavities with a mean value of remaining dentin thickness (RDT) ranging between 0.55 +/- 0.30-0.68 +/- 0.38 mm were prepared. The cavities were treated with the following adhesive systems: Etch and Prime 3.0 (EP), Single Bond (SB), Clearfil SE Bond (CSE), and Prompt L-Pop (PLP). The pulpal tissue responses to dentin adhesives were assessed histopathologically at postoperative periods of 7, 21, and 65 days, and the results were subjected to statistical analysis. A significantly greater adverse inflammatory response was observed with the materials EP and PLP, while a significantly lesser degree of disorganization in the odontoblastic zone was found with the materials SB and CSE, in the postoperative period of 65 days. In addition, a thicker predentin zone was observed where SB material was applied. Application of the selected adhesive systems to non-exposed cavities, with an RDT, which ranged between the above-mentioned rates, was correlated with slight to moderate inflammation and odontoblast reduction depending on the materials used as well as upon the RDT

Bond strength durability of self-etching adhesives and resin cements to dentin

OBJECTIVES: To evaluate the microtensile bond strength (µTBS) of one- (Xeno III, Dentsply) and two-step (Tyrian-One Step Plus, Bisco) self-etching adhesive systems bonded to dentin and cemented to chemically cured (C&B Metabond) or light-cured paste of a dual-cure resin cement (Variolink II, Ivoclar) within a short (24 h) and long period of evaluation (90 days). MATERIAL AND METHODS: Forty recently extracted human molars had their roots removed and their occlusal dentin exposed and ground wet with 600-grit SiC paper. After application of one of the adhesives, the resin cement was applied to the bonded surface and a composite resin block was incrementally built up to a height of 5 mm (n=10). The restored teeth were stored in distilled water at 37ºC for 7 days. The teeth were then cut along two axes (x and y), producing beam-shaped specimens with 0.8 mm² cross-sectional area, which were subjected to µTBS testing at a crosshead speed of 0.05 mm/min and stressed to failure after 24 h or 90 days of storage in water. The µTBS data in MPa were subjected to three-way analysis of variance and Tukey's test (&#945;= 0.05). RESULTS: The interaction effect for all three factors was statistically significant (three-way ANOVA, p<0.001). All eight experimental means (MPa) were compared by the Tukey's test (p<0.05) and the following results were obtained: Tyrian-One Step Plus /C&B/24 h (22.4±7.3); Tyrian-One Step Plus /Variolink II/24 h (39.4±11.6); Xeno III/C&B/24 h (40.3±12.9); Xeno III/Variolink II/24 h (25.8±10.5); Tyrian-One Step Plus /C&B/90 d (22.1±12.8) Tyrian-One Step Plus/VariolinkII/90 d (24.2±14.2); Xeno III/C&B/90 d (27.0±13.5); Xeno III/Variolink II/90 d (33.0±8.9). CONCLUSIONS: Xeno III/Variolink II was the luting agent/adhesive combination that provided the most promising bond strength after 90 days of storage in water