In vivo dentin bonding: the effects of remaining dentin thickness and tooth type

Abstract

Bond strengths of adhesive resins to ~dog dentin was measured in vivg on buccal and lingual surfaces of cuspids and molars. Sequential reductions in dentin thickness were made to compare bond strengths to superficial middle and deep dentin. Three resin systems were compared. Scotchbond, HEMA/Scotchbond and Scotchbond 2 The first two agents were applied to smear layer covered dentin, while Scotchbond 2 Primer was designed to remove the smear layer. Cuspid dentin bond strengths were greater than molars at all levels _ of remaining dentin thickness and across all agents. Agents bonded to smear layers formed bonds which were approximately half as strong as those achieved by the system which removed the smear layer. Across all teeth and agents, in vivo dentin bond ;strengths decreased in deeper dentin. Dentin bond strengths were expressed as percentages of enamel bond strengths. The dog as a bonding model is discussed.