Development of multicomponent glasses for application as a glazing layer on dental zirconia

Abstract

This study presents the development of multicomponent glasses for glaze layers for dental yttria‐stabilized tetragonal zirconia (Y‐TZP). The samples were melted in the temperature range of 1 250–1 400°C and were cast in water to obtain a frit. The frits were grounded to a powder with a particle size of less than 40 µm. To study the crystallization tendency of melted glasses, they were thermally treated at 800°C and X‐ray diffraction analyses were performed for both types of samples. The structure of the glasses was investigated by the Fourier‐transform infrared spectroscopy. The thermal expansion coefficient, CTE, the glass‐transition temperature, Tg, and the softening temperature, Ts, were defined. To test the glaze layer on zirconia ceramic, glass powders with different compositions were mixed with modeling fluid and applied on zirconia specimens and then fired at 800°C in a vacuum dental furnace. Scanning electron microscopy, SEM, was used to observe a cross‐section of the glass–ceramic contact on a glazed zirconia ceramic specimen. Glass with the highest content of alkaline oxides is characterized by the closest CTE to zirconium ceramics (10.10−6 K−1), the greatest transparency and good fluidity, and shows good adhesion to the zirconia. The glaze layer is homogeneous without cracks, pores, and crystals.