Role of CaF₂on mechanochemically synthesized leucite as dental veneering glass ceramics

Abstract

Leucite based glass ceramic is widely used in dental ceramics as porcelain fused to metals for veneering applications. Main properties considered here are high coefficient of thermal expansion and good mechanical properties. Owing to these requirements, high expansion phase such as leucite is incorporated in these glass ceramics. The present work was aimed to synthesise leucite using its stoichiometric batch compositions and subsequent high energy ball milling. CaF 2 was also added in another mix to study its role on leucite formation. Further prepared, leucite phase was added in separately prepared low temperature glass frit powders to control amount of glass and leucite content. X-ray diffraction results displayed that high energy ball milling and additive promoted the formation of leucite as a major crystalline phase. Furthermore, CaF 2 also suppressed the subsidiary crystallisation of kalsilite phase. Evaluated average coefficient of thermal expansion in the temperature range of 20-500uC was very close to the theoretical value of pure leucite.

Nonisothermal crystallization kinetics and stability of leucite and kalsilite from K2O‐Al2O3‐SiO2 glasses

“…Zhang et al reported that the formation of kalsilite is a transitional stage that leads to crystallization of leucite. In addition, other recent studies are consistent with the view that kalsilite is the precursor of leucite . Moreover, in some studies, it is indicated that the prolonged heat treatment of natural or synthesized kalsilite at elevated temperatures will gradually lead to a complete conversion to leucite and this phenomenon is believed to relate to the high volatility of potassium …”

In situ synthesis of leucite‐based feldspathic dental porcelain with minor kalsilite and Fe2O3 impurities

“…The mechanism in which CaF 2 acts is explained in Section . The eutectoid formed after CaF 2 incorporation contributed to the phase transformation from kalsilite to leucite . In Figure , CaF 2 has not been included in composition.…”

Mechanochemically synthesized leucite based bioactive glass ceramic composite for dental veneering

“…Ltd., Mumbai, India) were weighed in a stoichiometric ratio of leucite. This mixture was pulverized for 6 h in a high-energy planetary ball mill and subsequently fired at 1100 1C as discussed in our previous work [18]. Commercial Bioglass s 45S5 was prepared on a lab scale using traditional melt-quenching in a platinum crucible at 1400 1C.…”

“…This work also reports preparation of bioglass and low temperature frit (LTF) by traditional melt-quenching method [17,18]. Above three materials were mixed in an optimum ratio to form a composite with desirable properties.…”