Mechanical resistance of ceramic facets with and without overlap preparation

Abstract

the objective of this work was to analyze a dental prearation techinique in the confection of laminated facets higlighting the resistence of the set tooth/laminated facet in search for the adequate wear thickness for the vestibular surface as well as the confection or not of a palatal overlap. To tht aim 40 Cymell 1077 artificial teeth were used, divided into four groups according to earch type of preparation: Group 1: preparation with 1,0mm of wear in the vestibular face; 1,5mm of incisor reduction with palatal overlap of 1,0mm below the reduction. Group 3:: Preparation with 0,7mm in the vestibular face; 1,5mm of incisor reduction without palatalk overlap. Group 4: preparation with 0,7mm of wear in the vestibular face; 1,5mm of incisor reduction with palatal overlap of 1,0mm below the reduction. After dental preparation, lamined facets were confectioned in ceramic using the IPS Empress system with standard thickness estabilished by the dental preparation. The tooth/facet set were submete to mechanical in a universal mechanical testing machine using a speed of 1,0mm per minute. A device that simulated the conditions in the oral cavity was used. The results obtained were statically analyzed, which permnited to conclude that wear on the vestibular face, greater in thickness, and the presnce of an overlap in the incisor border working togther, significantly contribute to increase the mechanical resistance os ceramic facets.