Abstract: Objective　 Oral mucosa irritation and subcutaneous implantation tests were launched to study the histocompatibility of micro-arc oxidized Zr-Cu-Al-Ag bulk metallic glass (BMG). Methods　 Referring to the "biological test method for oral materials - oral mucosa irritation" published by National Institute of Drug Administration in 1995, and "biological evaluation of medical devices - Part sixth: local reaction after implantation" (10993-6:1994 ISO) in 1994, original BMG , micro-arc oxidized BMG and titanium alloy samples with dimension of Φ5╳0.5 mm2 for oral mucosa irritation and Φ1.5╳5 mm2 for subcutaneous implantation were prepared, respectively. Results　 The result of oral mucous membrane irritation test showed that all samples did not have local or systemic adverse reactions and the histopathological findings were also normal; the subcutaneous implant test displayed that the Zr-Cu-Al-Ag alloy had no apparent toxicity. After specimens was implanted one week, local tissue was found to be slightly red and swollen, and the biopsies showed a few of inflammatory cells; 4、12 weeks later, it was showed the inflammatory response gradually reduced as time prolonged, the formation process of fiber coated from loose to tight. The micro-arc oxidized Zr-base BMG is coated by fiber which is more dense than the comparative group. Conclusions　 As a new type of dental implant materials, the performance of Zr-base BMG is excellent, but its biological inert hindered the application of this material. Micro-arc oxidation treatment effectively reduces the biological inert of Zr-base BMG, while maintaining the excellent properties of Zr-base BMG at the same time, and good histocompatibility is obtained.

Key words: Zr-based BMG, Micro-arc oxidation, Oral mucosa stimulation test, Subcutaneous implantation test