3种金属成形技术制作的钴铬合金全冠表面质量的比较研究

A comparative study of surface quality of Co-Cr alloy crowns fabricated by three different technologies

目的:评价不同金属成形技术对钴铬金属全冠表面质量的影响。方法:采用失蜡铸造、计算机数控铣削(CNC)和选择性激光熔融(SLM)3种金属成形技术分别制作10个钴铬合金全冠,采用3D光学轮廓仪测量全冠自然表面和研磨抛光后表面的表面粗糙度(Ra)并用扫描电镜观察显微形貌,结果进行多均数比较的方差分析。结果:研磨抛光前后,3种技术制作的钴铬合金全冠的表面Ra均值差异均有统计学意义(P<0.05);研磨抛光处理可以显著降低全冠表面的Ra值(P<0.05);扫描电镜显示CNC组自然表面呈现规则磨痕,铸造组和SLM组自然表面粗糙且不规则;研磨抛光后3组全冠表面都更加光滑,特别是SLM组改变显著。结论:金属成形技术对钴铬合金全冠的表面质量有显著影响,研磨抛光可以有效改善钴铬合金全冠的表面质量,计算机数控铣削技术制作的钴铬合金全冠的表面质量优于选择性激光熔融和失蜡铸造技术。

Objective： To evaluate the effect of different manufacturing methods on the surface quality of Co-Cr alloy crowns. Methods： 30 Co-Cr alloy crowns were fabricated by lost-wax casting,computer numerical control milling（ CNC） and selective laser melting（ SLM） technology respectively（ n = 10）. Before and after grinding and polishing,the surface roughness（ Ra） of each crown was measured and surface morphology was observed by SEM. The data were analyzed by one-way ANOVA and Tukey’s test（ P 〈 0. 05）. Results： Significant differences were found among 3 groups both before and after grinding and polishing（ P 〈 0. 05）. SEM photos showed that the natural surface of CNC crowns had regular milling traces,but it was much rougher in SLM and casting groups. After grinding and polishing,the surface of crowns of the 3 groups became significantly smoother than before,especially that of SLM group. However,CNC group still had the smoothest and most homogeneous surface than the other 2 groups. Conclusion： The manufacturing method has significant influence on the surface quality of Co-Cr alloy crowns. Grinding and polishing can improve the surface quality of Co-Cr alloy crowns. CNC technology is beneficial to achieve good surface quality of the Co-Cr alloy crowns.