A study on microstructural characterization of the interface between apatite-wollastonite based glass ceramic and feldspathic dental porcelain

Abstract

In this study, the contact area between the glass ceramic containing apatite [Ca-10(PO4)6(O,F-2)] and wollastonite [CaO center dot SiO2] crystals (A-W glass ceramic) and feldspathic dental porcelain was characterized using scanning electron microscope and energy dispersive spectroscopy. Alumina-added A W glass ceramics were prepared by sintering glass compacts in the MgO-CaO-SiO2-P2O5-Al2O3 system at 1100 degrees C. Commercially available dental porcelains for alumina frameworks were applied on the A-W glass ceramic specimen by brushing and carving, and then fired at 960 degrees C using an electrically heated vacuum-furnace. Results revealed that veneering of feldspathic dental porcelain on alumina-added A-W glass ceramic is possible by an interaction between them, with which a diffusion process involving i) seperation of the phases forming the alumina-added A-W glass ceramic, ii) chemical diffusion of elements between alumina-added A-W glass ceramic and feldspathic dental porcelain, and iii) formation of an interface layer, is taking place. The system studied has interfacial characteristics similar to the commercially available dental materials currently used in restorative dentistry. Hence, it may be further processed for potential clinical applications.