Impact Adhesive Properties of Dental Composite Resins-Adh“ ion of Tooth Substance.

Abstract

Composite resin for dental use plays an important role as tooth restorative resin with in the severe oral environments. The composite resin, which is filled on occlusal surface of a molar tooth, requires high compressive strength and superior wear resistance, and strongly requires the superior adhesion to tooth substance and the sealing performance, in order to stand up to daily masticatory forces. So a lot of studies on adhesive strength of composite resin have been reported, but an adhesive property by impact testing has not been investigated to date. Afterfilled composite resin, its bonding agent existing in organization of tooth is formed as resin tags (length:5-100m) in enamel prism and dentinal tubule which run in direction of lower part inconsiderably toward a tooth axis. But, reports of investigating on effect of the resin tags on adhesive strength have apparently not been published to date. Inthisstudy, effect of such the resin tags with two different directions to impact forces, such as impact directions to tooth rootand tooth edge, on shear impact strength was examined using enamel and dentine of a bovine tooth as adherend, by using Izod impact testing. Asaresult, it be came clear that shear impact strength to enemel in case of impact direction to tooth rootshowed remarkably higher value comparin with that of another impact direction because of effect of resin tags with two impact directions. In case of dentin for adherend, the effect of such resin tags was not recognized.