Investigation on the Firing Behavior and Chemical Properties of Nano-Fluoroapatite-Fluorocanasite Glass- Ceramic Dental Glaze

The SiO2-B2O3-CaO-K2O-Na2O-CaF2 system was considered to synthesize fluorcanasite dental glass-ceramic glaze for the first time. For this purpose, 3, 6 (wt.%) P2O5 and 0.5, 1 (wt.%) Li2O were added as additives for crystallization of nano-size fluroapatite and in order to lower the firing temperature respectively. The compositions were melted at 1450 °C for 2h in an electrical furnace then the resulting melt was quenched in water to obtain frit glass. After milling and drying the resulting frits were shaped by single–axis pressing in the form of tablets (diameter 10 mm and height 5 mm). There are four different temperatures for firing. The final phases in the optimum temperature were detected by XRD (X-ray diffraction). Chemical resistant of the samples was calculated after firing according to weight loss. Morphology of crystals by SEM and their elements analysis by EDX were studied, to add 0.5 (wt.%) Li2O and 5 (wt.%) P2O5 increase chemical resistance and reduce the glaze firing temperature to 930 °C. According to Standard Dental (ISO 6872) this glaze can be used as opaque shade on substrate of dental impact.