抄録
Adhesive restorative composites have been used for dental clinical fields. So we examined the strength of adhesion between tooth substance and composite resin, used as restorative materials. Test method of adhesive strength, which simulated the force produced by mastication, was assessed by a push-out shear test, which is the new test method. The test specimens prepared ware then pressed to examine the adhesive strength of composite resin. The adhesive strength was highest for enamel, was lower for enamel/dentin and was lowest for dentin. The apparent adhesive strength, obtained from theoretical calculation, tended to show a constant relationship to the strength actually measured. This suggests that the effective adhesive area of the dentin is smaller than the area actually covered by the dentin. Furthermore, a gap, probably due to the effects of tensile stress, was observed in the adhesive interface between the composite resin and dentin. This gap seems to reduce the adhesive area, leading to a decrease on adhesive strength. Thus, the push-out shear test method appears to be useful in evaluating adhesive properties of composite resin.
