Effect of TiO ₂ on the sinter crystallization of nepheline glasses for dental application

Abstract TiO ₂ is known to play a key role in the controlled crystallization of “bulk processed nepheline glasses”. The aim of this study was to investigate the effect of adding TiO ₂ to a nepheline glass system made for powder processing to develop glass‐ceramics for dental applications via the sinter‐crystallization route. Three novel glass compositions based on the nepheline system were synthesized using the melt‐quench method. Glasses were designed to contain 3.0 mole % TiO ₂ , 6 mole % TiO ₂ , and one glass made free of TiO ₂ . Experimental glasses were ground into fine powders and then heat‐treated at identical crystallization schedules. The addition of TiO ₂ hindered the densification process during the sinter‐crystallization heat treatment. TiO ₂ free glass was found to sinter crystallize into a desirable material. In this study, the use of 3 mole % TiO ₂ and less was found to be effective in controlling the thermal properties without hindering the densification process during sinter crystallization.