Priliminary Experimental Studies On A Ceramic Material Of Orthodontic Bracket Developed By Ourselves

Objective :The aim of the study was to test the flexural strength and compressive strength of a ceramic material and evaluate prelimiinary its biacompatability in preparation for its next studies and orthodontic clinical use .Methods : According to the relative Chinese national standards and the technics of this ceramic bracket, specimens were made from its raw materials. These specimens were tested on MTS810. When they were. broken, the data of their flexural strength and compressive strength were recorded. then these data were compared with the flexural strength and compressive strength of foreign homogeneous products. In addetion, the cytotoxicity of this ceramic was investigated by cell culture in vitro and agar diffusion test, and the oral mucous membrane irritation response of this ceramic was evaluated using rabbits.Results : The results showed that its flexural strength was 263. 75 ±22. 59MPa, its compressive strength 1549. 906±85. 677MPa, which were no less than the flexural strength and the compressive strength of the foreign homogeneous products. In addition, the level of cytotoxicity of this ceramic was grade 0, and the local or systemic abnormal response on rabbits including histopathological findings was not observed in the oral mucous membrane irritation test.Conclusion : The results seem to indicate that the flexural strength and compressive strength of this ceramic material can meet therequirements of the orthodontic clinic, and it has no cytotoxicity or abnormal oral mucous membrane irritating response.