PURPOSE: To evaluate the marginal adaptation (in terms of % continuous margin) and microtensile bond strength (microTBS) of the enamel and dentin of direct class II composite restorations. METHODS: 32 standardized class II cavities were prepared with the gingival margin of one box occlusal to the cementum-enamel junction (CEJ) and one gingival floor extended beyond the CEJ. The teeth (n= 8) were restored using one of four adhesive systems [Adper Scotchbond Multi Purpose (SMPP), Adper Scotchbond 1 XT (S1XT), Clearfil SE Bond (CSEB), or Clearfil Tri-S Bond (CTSB)] with incrementally placed composite restorations before being stored in water (24 hours), thermocycled (2,000 cycles, 5 to 55 degrees C) and mechanically loaded (50,000 cycles, 50 N). Marginal adaptation was evaluated by SEM. Additionally, the teeth were sectioned and trimmed to obtain specimens for microTBS testing. RESULTS: All adhesive systems exhibited "continuous margins" in enamel over 95.4%, whereas "continuous margins" in dentin ranged from 60.2 to 84.8%. CSEB and CTSB yielded significantly more "continuous margins" between the adhesive restoration and dentin than SMPP or S1XT (P< 0.05). The mean microTBSs (MPa) for enamel were 40.5 (SMPP), 37.3 (S1XT), 30.8 (CSEB) and 23.2 (CTSB), and for dentin, they were 37.7 (SMPP), 33.0 (S1XT), 37.3 (CSEB) and 29.0 (CTSB).
PURPOSE: To evaluate the marginal adaptation (in terms of % continuous margin) and microtensile bond strength (microTBS) of the enamel and dentin of direct class II composite restorations. METHODS: 32 standardized class II cavities were prepared with the gingival margin of one box occlusal to the cementum-enamel junction (CEJ) and one gingival floor extended beyond the CEJ. The teeth (n= 8) were restored using one of four adhesive systems [Adper Scotchbond Multi Purpose (SMPP), Adper Scotchbond 1 XT (S1XT), Clearfil SE Bond (CSEB), or Clearfil Tri-S Bond (CTSB)] with incrementally placed composite restorations before being stored in water (24 hours), thermocycled (2,000 cycles, 5 to 55 degrees C) and mechanically loaded (50,000 cycles, 50 N). Marginal adaptation was evaluated by SEM. Additionally, the teeth were sectioned and trimmed to obtain specimens for microTBS testing. RESULTS: All adhesive systems exhibited "continuous margins" in enamel over 95.4%, whereas "continuous margins" in dentin ranged from 60.2 to 84.8%. CSEB and CTSB yielded significantly more "continuous margins" between the adhesive restoration and dentin than SMPP or S1XT (P< 0.05). The mean microTBSs (MPa) for enamel were 40.5 (SMPP), 37.3 (S1XT), 30.8 (CSEB) and 23.2 (CTSB), and for dentin, they were 37.7 (SMPP), 33.0 (S1XT), 37.3 (CSEB) and 29.0 (CTSB).