Abstract: Objective： MTT colorimetric assay was used to detect the cytotoxicity of titanium alloy dental im- plant cast by 3D printing technology, and to evaluate the feasibility of the new casting process, so as to provide theoretical basis for further clinical application. Methods： We used professional software design to build the computer model, selected two different titanium alloys Ti-6Al-4V and Ti-6Al-7Nb as the casting raw materials, and cast three kinds of experimental standard plates of the same specification by 3D printing technology. The experiment was mainly divided into three groups, namely Ti-6Al-4V group, Ti-6Al-7Nb group and blank control group. By MTT colorimetric assay, we tested the effects of these three standard components on the proliferation rate of osteoblast MG63 to complete the evaluation of 3D printing technology. Results： Under the inverted phase contrast microscope, we observed that the growth status of cells in the three groups were all good, and there was no significant difference in cell morphology between the experimental group and the blank control group. MTT colorimetric results showed that the cy- totoxicity level of the two groups of titanium sheets was 0. Meanwhile, the proliferation rate of Ti-6Al- 7Nb titanium alloy sheets was slightly higher than that of Ti-6Al-4V titanium alloy sheet extraction solu- tion group. Conclusion： The cytotoxicity level of titanium alloy implants cast by 3D printing technology meets the requirements of clinical application of oral implant materials, and the cytotoxicity level of Ti- 6Al-7Nb is slightly lower than that of Ti-6Al-4V

Key words: 3D printing, TC4, implant, cytotoxicity