Fabrication of dental ceramics from silicon nitride core with borosilicate glass veneer

Abstract

Silicon nitride ceramic is a potential material for clinical indications due to its high fracture toughness, strength, and non-cytotoxicity. For this reason, Si 3N 4 ceramic is interested to apply for dental core. The superiority of Si 3N 4 ceramic is the low coefficient of thermal expansion (CTE) which is lower than that of zirconia and alumina ceramics that are popular in this field. In this study, borosilicate glass powder with 5 wt% of zirconia addition was prepared by melting at 1450 °C for 1 h. The glass melt was quenched and was then ground to be a powder and mixed with polyvinyl alcohol solution to be a paste. The Si 3N 4 specimens coated with the veneer were fired in electrical tubular furnace at 1100 °C for 15 min. The appearance of these specimens shows smooth, glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.05×10 -6 °C -1 and the Vickers hardness as 4.0 GPa which is close to the human teeth. The specimens were tested by human gingival and periodontal ligament fibroblasts (HGF and HPDLF) and cytotoxicity by MTT assay. The results indicated that Si 3N 4 ceramic and borosilicate glass can be used as dental materials. © (2012) Trans Tech Publications.