Tensile bond strength of indirect composites luted with three new self-adhesive resin cements to dentin

objective: the aims of this study were to evaluate the tensile bond strengths between indirect composites and dentin of 3 recently developed self-adhesive resin cements and to determine mode of failure by sem. material and methods: exposed dentin surfaces of 70 mandibular third molars were used. teeth were randomly divided into 7 groups: group 1 (control group): direct composite resin restoration (alert) with etch-and-rinse adhesive system (bond 1 primer/adhesive), group 2: indirect composite restoration (estenia) luted with a resin cement (cement-it) combined with the same etch-and-rinse adhesive, group 3: direct composite resin restoration with self-etch adhesive system (nano-bond), group 4: indirect composite restoration luted with the resin cement combined with the same self-etch adhesive, groups 5-7: indirect composite restoration luted with self-adhesive resin cements (relyx unicem, maxcem, and embrace wetbond, respectively) onto the non-pretreated dentin surfaces. tensile bond strengths of groups were tested with a universal testing machine at a constant speed of 1 mm/min using a 50 kgf load cell. results were statistically analyzed by the student's t-test. the failure modes of all groups were also evaluated. results: the indirect composite restorations luted with the self-adhesive resin cements (groups 5-7) showed better results compared to the other groups (p<0.05). group 4 showed the weakest bond strength (p>0.05). the surfaces of all debonded specimens showed evidence of both adhesive and cohesive failure. conclusion: the new universal self-adhesive resins may be considered an alternative for luting indirect composite restorations onto non-pretreated dentin surfaces.