EVALUATION OF COMPOSITE WEAR WITH A NEW MULTIMODE ORAL WEAR SIMULATOR

Objectives. The goals of this study were to develop a machine which si multaneously produces wear through the two main oral wear mechanisms o f abrasion and attrition by the action of an enamel antagonist and to compare the results obtained for dental composites using this machine to those obtained from clinical studies and other in vitro studies. Me thods. The accuracy of this new wear tester was determined by examinin g 11 commercial composite filling materials and 1 amalgam. Specimens w ere subjected to three-body abrasion and attrition wearier 50,000 cycl es. Profilometry was used to quantitate wear of the composites. Linear regression analysis was used to correlate the results to those obtain ed from clinical studies, as well as from other in vitro wear testers. The area of enamel wear was also determined by image analysis. The SE M was used to evaluate the wear surfaces. Results. The lowest abrasion wear was recorded for the amalgam and the microfill and smaller-parti cle composites. Attrition wear was enhanced for the microfill composit es and one small-particle hybrid. There was a strong correlation betwe en the results obtained with the new wear tester and those obtained in the clinical trials cited in the literature. Wear of the enamel antag onist was the greatest for the composites with the largest particle si zes. The wear tester showed a reasonable correlation with other wear-p roducing machines. Significance. A new wear tester developed to evalua te and discriminate abrasion and attrition wear provided results simil ar to those reported in the literature for a variety of commercial com posites. The new machine is capable of characterizing the behavior of a material in multiple wear modes simultaneously with one simple, real istic test.