Silicon nitride (Si3N4) ceramic is an attractive material for dental applications, especially used as a dental core material, due to its unique properties including high fracture toughness, high strength, high wear re...Silicon nitride (Si3N4) ceramic is an attractive material for dental applications, especially used as a dental core material, due to its unique properties including high fracture toughness, high strength, high wear resistance and non-cytotoxicity. In this study, the Si3N4 ceramic was fabricated by a non-pressure sintering technique at a relatively low sintering temperature of 1650℃ in nitrogen atmosphere. Borosilicate glass and 5 wt% ZrO2-added borosilicate glass were used for coating on the Si3N4 core surface because of their compatibility in thermal expansion, high chemical resistance and bio-inert. The specimens were then fired in electric tube furnace at 1100℃. The Vickers microhardness of borosilicate glass and 5 wt% ZrO2-added borosilicate glass veneering materials were measured and compared with the commercial dental veneer porcelain as a control (VITA VMK 95). The cytotoxicity of the Si3N4 ceramic and the veneering materials were tested by MTT assay, using human gingival fibroblasts (HGF) and periodontal ligament fibroblasts (HPDLF). The results indicate that the Si3N4 ceramic and Si3N4 ceramic veneered with borosilicate glass or 5 wt% ZrO2-added borosilicate glass veneering materials tested in this study are not toxic to oral tissue and can be used to produce dental prostheses.展开更多
文摘Silicon nitride (Si3N4) ceramic is an attractive material for dental applications, especially used as a dental core material, due to its unique properties including high fracture toughness, high strength, high wear resistance and non-cytotoxicity. In this study, the Si3N4 ceramic was fabricated by a non-pressure sintering technique at a relatively low sintering temperature of 1650℃ in nitrogen atmosphere. Borosilicate glass and 5 wt% ZrO2-added borosilicate glass were used for coating on the Si3N4 core surface because of their compatibility in thermal expansion, high chemical resistance and bio-inert. The specimens were then fired in electric tube furnace at 1100℃. The Vickers microhardness of borosilicate glass and 5 wt% ZrO2-added borosilicate glass veneering materials were measured and compared with the commercial dental veneer porcelain as a control (VITA VMK 95). The cytotoxicity of the Si3N4 ceramic and the veneering materials were tested by MTT assay, using human gingival fibroblasts (HGF) and periodontal ligament fibroblasts (HPDLF). The results indicate that the Si3N4 ceramic and Si3N4 ceramic veneered with borosilicate glass or 5 wt% ZrO2-added borosilicate glass veneering materials tested in this study are not toxic to oral tissue and can be used to produce dental prostheses.
