制备高性能氧化锆陶瓷牙科修复体的初步研究

Primary Study On Fabrication Of High Performance Dental ZrO_2 Ceramics Restoration.

目的 :本文对以氧化钇稳定四方相氧化锆 (Y -TZP)纳米微粉为原料 ,经部分烧结 -牙科计算机辅助设计/计算机辅助制造系统 (CAD/CAM)加工 -完全烧结三步法制备高性能的牙科修复体的工艺路线进行了初步探索。方法 :先经模压成型 ,低温烧结 ,制作了可供CAD/CAM加工的部分烧结Y -TZP陶瓷块 ;然后经牙科CAD/CAM机加工 ,得到初步的牙科修复体 ;最后对此修复体进行完全烧结 ,得到高性能的氧化锆牙科修复体。结果 :部分烧结的陶瓷块的切削性能优良 ,与CAD/CAM预期时间吻合。完全烧结的陶瓷材料机械性能优良 ,弯曲强度达到710MPa,断裂韧性达到 4 .77MPa·m1/ 2 。在完全烧结过程中 ,各个方向收缩均匀一致。得到的牙冠形态逼真 ,无裂纹。结论 :部分烧结 -CAD/CAM加工

Objective: In this paper, the technology route of fabricating high performance dental restoration via partial sintering-CAD/CAM-full sintering three steps method was primarily studied, where Y 2O 3-stabilized tetragonal zirconia polycrystal (Y-TZP) nanometer crystalline powder was used as raw material. Methods:First,Partial sintered Y-TZP blank was manufactured by molded shape at 25MPa, sintered at low temperature. Second,The initial dental framework was obtained by machining the blank on dental CAD/CAM system. Third,the ultimate high performance dental restoration was obtained by full sintered the initial dental framework. Results:To fabricate a dental crown, the machining time of partial sintered ceramic blank was equal to the machine anticipation time. The full sintered Y-TZP had excellent mechanical properties, with bending strength of 710 MPa, fracture toughness of 4.77 MPa·m 1/2 . During full sintering process, the shrinkages of dental crown in different spatial dimensions were equality and uniformity. The dental crown had verisimilitude configuration, and had no crack on surface. Conclusion: Y-TZP can be used as a new promising ceramics to fabricate molars crowns and bridges, because their strength are 3-5 times stronger than those of current dental ceramics. The technology route of partial sintering- CAD/CAM- full sintering three steps method is also a feasible simple way to fabricate high performance dental restoration.