Effect of smear layer thickness and chlorhexidine application on shear bond strength of resin composite bonded to normal dentin utilizing one step self-etch adhesive

Abstract

This research was designed to investigate the effect of smear layer thickness and chlorhexidine application on shear bond strength of resin composite bonded to normal dentin utilizing a universal adhesive in self-etch mode. A total of 24 freshly extracted, sound, non-carious, human permanent molars were used in the study. Each tooth was sectioned mesio-distally into two halves down to the root then each half was cut at level of a cemento-enamel junction to remove root portion, then each half was embedded into a self-curing acrylic resin to give 48 dentin specimens. Forty dentin specimens were used in shear bond strength testing and eight specimens for scanning electron microscopic examination. Forty dentin specimens were divided into two main groups according to smear layer thickness. Each main group was subdivided into two subgroups according to 2 % Chlorhexidine treatment of dentin surface