Question

Effect of different mechanical and chemucalsurface treatmentson repaired bondstrengthof indirect composite kimyai s resin

Answer 1

This study compared the effects of two mechanical surface preparation techniques, air abrasion and Nd:YAG laser, with the use of two adhesive systems, self-etch and etch and rinse, on the repair bond strengths of an indirect composite resin. One hundred fifty cylindrical samples of an indirect composite resin were prepared and randomly divided into six groups (n = 25). In groups 1-3, the composite resin surfaces were respectively prepared as follows: no roughening, roughening by air abrasion, and roughening by Nd:YAG laser, followed by application of an etch-and-rinse adhesive. In groups 4-6, the preparation techniques were respectively the same as those in groups 1-3, followed by application of a self-etch adhesive. Subsequently, a direct composite resin was added and repair bond strengths were measured. Data were analyzed with two-way ANOVA and post hoc Tukey's test. Mean bond strength value was significant based on the preparation technique (P < 0.001), i.e., in air abrasion and Nd:YAG laser groups, bond strengths were significantly higher compared to no-preparation groups (P < 0.0005). There were significant differences in bond strength values between air abrasion and Nd:YAG laser groups, with significantly higher values in air abrasion groups (P < 0.0005). However, there were no significant differences in bond strength values between the adhesive