Microhardness and Biocompatibility of Silicon Nitride Ceramic Developed for Dental Applications

Rayaa Wananuruksawong^1,2, Thanakorn Wasanapiarnpong^1,2, Nirada Dhanesuan³, Pavinee Padipatvuthikul Didron³

¹Research Unit of Advanced Ceramic, Department of Materials Science, Faculty of Science, Chulalongkorn University, Bangkok, Thailand.
²National Center of Excellence for Petroleum, Petrochemical, and Advanced Material, Chulalongkorn University, Bangkok, Thailand.
³Faculty of Dentistry, Srinakharinwirot University, Bangkok, Thailand.

DOI: 10.4236/msa.2014.514106                

Abstract

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.

Keywords

Silicon Nitride, Ceramic, Microhardness, Biocompatibility, Dentalcore

Conflicts of Interest

The authors declare no conflicts of interest.

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