MATERIALE PLASTICE ♦ 47♦ Nr. 3 ♦ 2010 375 Tribological Comparative Study on Two Composite Materials for Restorative Dental Applications in Smoking Affected Teeth STELA CARMEN HANGANU 1 *, ADINA OANA ARMENCIA 1 ,STEFAN GRIGORAS 2 , LUCIAN CONSTANTIN HANGANU 2, PETRICA VIZUREANU 3 1 „Gr. T. Popa” University of Medicine and Pharmacy, 16 Universitãþii Str., 700115, Iaºi, Romania 2 „Gheorghe Asachi” Technical University of Iasi, Faculty of Mechanical Engineering, 71 Mangeron Blv.,700050, Iasi, Romania 3 „Gheorghe Asachi” Technical University of Iasi, Faculty of Material Science and Engineering, 71 Mangeron Blv.,700050, Iasi, Romania Due to the multitude of restorative materials on the today market, the studies presented in this paper come to make some contributions regarding the evaluation of biomaterials in terms of resistance to the wear process, the factors influencing the tribological behaviour of hard structures and restorative dental biomaterials in the oral environment. Keywords: composite materials, tribology, wear, dental medicine There are nowadays modern means of investigation and assessment of biomechanical properties of biomaterials and restorative dental structures, characteristic of the last decade being the moving of research from the macroscopic to the microscopic level, from destructive means for resistance determination to the non-destructive methods. In this way, the literature gives a major interest on the problems specific for tooth wear, how to approach and solve the many existing forms of wear [1]. There are still a number of uncertainties related to tribological events in the oral cavity and thus hard dental structures. Different mechanisms of production, corellation between shape and events, and new biomaterials such as composites appeared on market justified to focus the study on these aspects. * email: carmenhanganu1957@yahoo.com But the main parameter used to assess the phenomenon of wear is the volume of spent material. Experimental part To determine the wear coefficient and the volume of spent material were tested two types of composite materials used in restorative dentistry practice: D.SIGN (IVOCLAR) and VM13 (VITA-VIDENT TN ) from which there were made samples in the form of discs with a radius of 25 mm and a thick of 2 mm (0.5 mm metallic support and 1.5 mm phiz composite component). The experiment was realized using a CALOWER-CS tribometer [2]. The applied methodology and all imposed conditions for experimental researches were presented in [3]. Fig. 1. Average volume of spent material depending on the length of friction for D.SING composites Tabel 1 VOLUME OF SPENT MATERIAL AND THE COEFFICIENT OF ABRASIVE WEAR FOR D. SING COMPOSITES