Effects of Dentin Conditioning on Bond Strengths and Interfacial Morphology
Sabine H. Dickens
Bonding to dentin is critically influenced by the age and mineral content and the iatrogenic state of the dentin. The latter is affected by altering the smear layer, which leads to a mineral-deprived, collagen-rich surface. Various treatments aimed at improving dentin permeability for the subsequently applied adhesive resin have been used or proposed. The treatments include nonacid-induced alterations through polishing or a neutral pH chelator, conditioning with acids of varying pH, or with a polymerizable acidic conditioner that contains both acid and methacrylate functionalities. In this presentation, changes in the micromorphology of the tooth structure caused by the various acid and nonacid surface treatments and their effect on shear bond strengths to dentin or enamel are surveyed. Transmission or scanning electron microscopy was used to discern and relate ultrastructural changes caused by the various conditioning treatments to interfacial shear bond strengths.