COMPARACIÓN DE LA RESISTENCIA DE TRES SISTEMAS CERÁMICOS EN TRAMOS PROTÉSICOS FIJOS ANTERIORES. ANÁLISIS POR ELEMENTOS FINITOS1/COMPARISON OF THE RESISTANCE OF THREE CERAMIC SYSTEMS IN ANTERIOR FIXED PROSTHETIC Segments. A FINITE ELEMENT ANALYSIS1

The purpose of this study was to evaluate stress distribution on three-unit fixed partial dentures (FPD) in the anterior region, made of three ceramic systems with connector variations. The study was performed by the finite element method. Four segments of FPD were modeled, three of them were made on ceramic systems: lithium disilicate, alumina, and zirconia, and the fourth model was lithium disilicate with a connector of 9 mm^sup 2^ in area. The modeling included three variables: elastic modulus, Poisson's ratio, and ultimate tensile strength. All the ceramic systems showed a suitable behavior for FPDs in the anterior area; the structure's elastic modulus influences stress behavior; if it is higher, it reduces stresses in feldspar ceramics and periodontal ligament. The authors noted that in presence of a connector of 16 mm^sup 2^ in area, the periodontal ligament received greater stresses as a compensation effect, but they significantly decreased in the structure.