Estudo de contração para adaptação de elementos de zircônia translúcida em aplicação odontológica

Abstract

The use of non-biological materials in dental prostheses has been recorded about 3000 years b.C. Nowadays, ceramics are the materials that best meet the requirements for dental application, with translucent zirconia being the most evident today. The technology for the production of ceramic prostheses, that is gaining space in the market is the use of Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM), thanks to the faster production and the high surface finish. The present work studied the linear contraction during the sintering process of three types of commercial zirconia. This study realized was the processing of this material, that changed of the pressures were made during the isostatic pressing stage. The following pressures 60, 100, 150, 200 and 250 MPa were used and, at the end of the sintering process, the linear contraction at each pressure was evaluated. To ensure total contraction, it was necessary to determine if there was complete sintering, thus calculating the percentage of densification for each sample with a value greater than 97%. The linear contraction results found ranged from 17% to 22%, which is in accordance with the literature for the material, but the most important is the previous knowledge of this contraction bearing in mind that the average tolerance for the intended application can not exceed 0.1 mm. Most of the samples met the tolerance, with its maximum value reaching 10,28 mm and minimum 9,93 mm, evidencing the possibility of using the method for the manufacture of dental prostheses.