Influência do posicionamento na mufla durante cocção na translucência de cerâmica feldspática sobre subestruturas de zircônia e alumina

Abstract

The aesthetic requirement, compared to a cultural movement that spread through the population, has covered several areas and has also motivated the industry dedicated to the development of dental materials to research products that best meet the expectations of professionals / patients. Substructures in zirconia enable the fabrication of esthetic restorations on natural teeth or dental implants, highlighting the flexural strength and biocompatibility, and this above 1000 MPa. The application of the coating is ceramic bodies which ensures a natural, reproducing features normally found in natural teeth. This similarity should be present in the optical properties feldspathic ceramic, especially opalescence, fluorescence and translucency, which allow light to be incident fractional part that is reflected, transmitted or absorbed by the structure. A crucial factor in the longevity of restorations, is the adherence and resistance of ceramic bodies with axial and lateral forces that occur during function. The flexural strength of feldspathic ceramic remains the same, being between 46.4 to 120 MPa. Moreover, Zirconia has low thermal conductivity and diffusivity, and the way the feldspathic ceramic adheres to its surface is not fully understood, unlike what happens on metal structures. All above data are related to greater delamination of veneering porcelain reported on zirconia substructures. There are several articles that describe alternatives to improve the adhesion of the veneering ceramic zirconia. Among these, a form of substructure that reduces the volume and give better support to ceramics, as well as a protocol for heating and cooling during slower cooking, seem to be the most effective ways. This study aims to assess the aesthetic end. How the positioning in the muffle kiln, center or periphery during cooking on the feldspathic ceramic zirconia substructures, influences the brightness and chromaticity, and if this fact would have clinical relevance