PUSH-OUT STRENGTH AND SEM EVALUATION OF RESIN COMPOSITE BONDED TO INTERNAL CERVICAL DENTIN

The bond strength of a resin composite used with a dual-cured dentin b onding system to internal cervical bovine dentin was evaluated using a direct or indirect placement technique. Teeth were sectioned transver sely to produce 4 mm-thick specimens. The root canals were enlarged to a standardized taper, treated with a dentin bonding system, and fille d with a light-cured resin composite using either direct, incremental composite placement or indirect composite placement of a pre-polymeriz ed composite inlay. The debond stress of indirectly placed restoration s using a composite inlay was 8.5 (SD+/-2.7) MPa which was significant ly greater (p<0.0001) than the value of 5.0 (SD+/-1.9) MPa for composi te placed in a conventional, incremental manner. SEM evaluation reveal ed the indirect placement technique demonstrated increased resin tag d ensity and length as compared to the direct technique. Enhanced retent ion of resin composite to endodontically prepared dentin treated with a dentin bonding system was obtained by using a composite inlay techni que as opposed to direct, incremental buildup of the material.