Micro-shear bond strength of five resin-based composites to dentin with five different dentin adhesives

Purpose: To test whether the combination of dentin adhesive and resin-based composite from the same manufacturer had higher micro-shear bond strength than the other combinations of different manufacturers. Methods: 25 experimental micro-shear bond test groups were made from the combination of five resin-based composites and five dentin adhesives (three total-etch adhesives and two self-etch adhesives) with extracted human molars stored in saline for 24 hours. The test was performed with the wire-loop method using a universal testing machine, and the micro-shear bond strengths were calculated. SEM photomicrographs of fractured sites were taken to check the failure mode. Results: The combinations from same manufacturers failed to show higher bond strengths than the other combinations. Self-etch adhesives showed significantly higher micro-shear bond strengths than total-etch adhesives (P < 0.05). In total-etch adhesives, the kind of resin composite was important and in self-etch adhesives, the kind of adhesive had significant effect on micro-shear bond strength (P < 0.05). All sites showed mixed fractures.