Zirconia toughened mica glass ceramics for dental restorations: Wear, thermal, optical and cytocompatibility properties

Abstract

BackgroundIn an effort to design novel zirconia reinforced mica glass ceramics for dental restorations, clinically relevant properties such as wear, coefficient of thermal expansion, optical transmittance, and cytocompatibility with human gingival fibroblast cell lines were investigated in the present study. Materials & MethodsMicrostructure analysis of two body wear of heat treated mica glass ceramic ceramics (47.2 SiO2–16.7 Al2O3–9.5 K2O–14.5 MgO–8.5 B2O3–6.3F wt.%) reinforced with 20wt.% YSZ, were evaluated against a steatite antagonist in a chewing simulator following Willytec Munich method. In addition, Coefficient of thermal expansion (CTE), total transmittance, scattering coefficient and cytocompatibility on human gingival fibroblast cell lines were performed and compared to the commercially available dental ceramic systems. ResultsThe experimental mica glass ceramic demonstrate micro-ploughing, pull out and debris formation along the cutting surface, indicating abrasive wear mechanism. Thermal expansion of mica glass ceramic composite was recorded as 5×10−6/°C, which is lower than the thermal expansion of commercially available core and veneering ceramics. Further, significant differences of transmittance and scattering coefficient of mica glass ceramics with 20wt.% YSZ with commercial dental ceramics was found and extensive fibroblast cell spreading with filopodial extension, cell-to-cell bridges and proliferation with human gingival fibroblast cell lines. ConclusionWith acceptable cytocompatibility with human gingival fibroblast cells and better wear properties with respect to commercial IPS emax Press, the mica glass ceramic composites (47.2 SiO2–16.7Al2O3–9.5 K2O–14.5 MgO–8.5 B2O3–6.3F wt.%) with 20wt.% YSZ have the potential for dental restorative applications as machinable veneering ceramics.