Constancy of bond strength in 5 single-bottle dentin bonding systems

Objective: Historically, wide variations in the shear bond strength of resi n composite bonded to dentin have been reported,The purpose of this study w as to compare 5 commercially available single-bottle dentin banding systems while controlling several sources of variation in shear bond strengths. Me thod and materials: Extracted molars were stored for 2 weeks in 0.5% Chlora mine T. The teeth were mounted, the occlusal enamel was removed to expose m iddle dentin, and the exposed dentin was etched and treated according to 1 of 6 protocols. Finally, a cylinder of resin-based composite was bonded to the dentin. After 24 hours, specimens were fractured under shear force, and the results were recorded in megapascals, Results: The type of product use d was significantly associated with the mean shear bond strength observed. All products exhibited some degree of variation from specimen to specimen. One product, PQ1, exhibited less variation than the other 4 products. Concl usion: PQ1 was found to have a significantly higher mean shear bond strengt h than the other 4 products tested. There was no significant difference bet ween specimens bonded to dry dentin and specimens bonded to wet dentin when using PQ1.