Adhesion of resin composite to enamel and dentin: a methodological assessment

摘要

This study compared the impact of four test methods on adhesion of resin composite to enamel and dentin. Human molars (N = 54) were randomly assigned to test the adhesion of resin composite material (Quadrant Universal LC) using one of the following test methods: (a) macroshear test (SBT; n = 16), (b) macrotensile test (TBT; n = 16), (c) microshear test (mu SBT; n = 16) and (d) microtensile test (mu TBT; n = 6). In a randomized manner, buccal or lingual surfaces of each tooth, were assigned as enamel or dentin substrates. Enamel and dentin surfaces were conditioned using an etch-and-rinse adhesive system (Syntac Classic). After storage (24 h, 37 degrees C), bond tests were conducted in a Universal Testing Machine (1 mm/min) and failure types were analyzed. Data were analyzed using Univariate and Tukey's, Bonneferroni tests (a = 0.05). Two-parameter Weibull modulus, scale (m) and shape (0) were calculated. Test method (p 0.001) and substrate type (p 0.001) significantly affected the results. When testing adhesion of resin composite to enamel, SBT (25.9 +/- 5.7)(a), TBT (17.3 +/- 5.1)(a,c) and mu SBT (27.2 +/- 6.6)(a,d) test methods showed significantly higher mean bond values compared to mu TBT (10.1 +/- 4.4)(b) (p 0.05). Adhesion of resin composite to dentin did not show significant difference depending on the test method (12 +/- 5.7-20.4 +/- 4.8; p 0.05). Only with SBT, significant difference was observed for bond values between enamel (25.9 +/- 5.7) and dentin (12 +/- 5.7; p 0.05). Weibull distribution presented the highest shape values for enamel-mu SBT (29.7) and dentin-mu SBT (22.2) among substrate-test combinations. Regardless of the test method, cohesive failures in substrate were more frequent in enamel (19.1%) than in dentin (9.8%).