Durability evaluation of the shade characterization layer on monolithic ceramics

Abstract

The characterization layer can be applied over monolithic ceramics to improve the aesthetic quality of the restorations, and it can be veneered by glaze that would have a protective function for the underlying material. Both layers are subjected to the natural wear process that happes in the oral environment, which may occur during mastication, touch and/or tooth tightening and brushing. The objectives of this study are the evaluation the effect of wear methodologies that simulate mastication with different antagonists, abrasion and brushing on ceramic materials available for monolithic restorations (Part I), as well as the action of these wear techniques on a characterization layer of hybrid polymer ceramic (PIC) applied after different surface treatments on presence or not og the glaze layer (Part II). In Part I, a high translucency zirconia (YZHT), zirconia reinforced lithium silicate (ZLS) and feldspathic (FD) ceramics will be tested. In step II, the PIC surface will be treated with polishing, hydrofluoric acid and silanization, blasting and silanization, or application of a self-etching silane. After measurement of the initial roughness of all specimens, different specimens from each experimental group will be tested under three-body wear, brushing wear and simulation of physiological wear with steatite, PIC or YZHT antagonists, followed by biaxial flexion test. Specimens will be subjected to a topographic analysis with the aid of stereomicroscope, scanning electron microscope and X-ray spectroscopy. The data of wear, roughness and flexural strength will be statistically analyzed, and images will be described. The results will be discussed ahead of the relevant literature. (AU)