To Evaluate The Wear Resistance Of Composite Resin Opposed By Human Enamel Antagonist In Vitro

Objective To evaluate the wear resistance of four types of composite resin BEAUTIFIL, SureFilTM, TE-Econom and Charisma when they were opposed by human enamel antagonist.To study the relationship about the wear resistance between hardness and the pH value.Methods Mutual wear between four types of composite resins(3×20×1mm thick)with same rough surface and opposing enamel was evaluated in a wear simulator of UMT-2.Wear resistance was assessed as weight loss(g) and the hardness of composite resin was tested by digital micro-hardness meter.The worn surfaces were observed by scanning electron microscope(SEM).All data were statistically analyzed by one-sample T Test and one-way ANOVA and spearman rank correlation.(α=0.05)Results The weight loss of the BEAUTIFIL, SureFilTM, TE-Econom composite resin by every 6000 strokes was not equal,except Charisma composite resin.The wear resistance of the materials tested was not related to their hardness(p>0.05).SEM observation showed that the fillers particles of BEAUTIFIL, SureFilTM were bigger than the other, Charisma was the smallest and well-distributed.Many filler particles were loose or missing.There were many scratch on Charisma composite clearly. In the acid environment ,the enamel surface had the special appearance. The weight loss of the BEAUTIFIL, SureFilTM ,TE-Econom composite resins increased when pH value fell down to 4.0 (p<0.05),Resin Charisma did not changed remarkably (p>0.05).Conclusion If the filler particles of the composite resin was tiny and uniformed,the weight loss of the wear were consistent and less.The hardness of the composite resin can not reflect the wear resistance. The weight loss was accelerated while the pH value decreased.