不同构建角度和支撑密度对选区激光熔化钴铬合金卡环准确性的影响

Effect of build angles and support densities on selective laser melting accuracy of cobalt-chromium clasps

目的评价不同构建角度和支撑密度对选区激光熔化钴铬(CoCr)合金卡环准确性的影响。方法3D软件构建一倒凹深度为0.50 mm的卡环样本数据(参考对象),将其导入金属3D打印机中,在不同构建角度(0°、45°和90°)和不同支撑密度(0.50、0.70、0.90和1.10 mm)条件下成型,得到CoCr合金卡环。采用模型扫描仪获取所有卡环的扫描数据(测试对象),在Geomagic软件中将测试对象与参考对象、测试对象与测试对象进行最佳拟合配准,获得卡环的准确性均方根误差(RMSE)值;采用单因素方差分析或非参数秩和检验对数据进行统计分析(α=0.05)。结果在正确度方面,支撑密度0.50 mm下,不同构建角度组按RMSE值排序为90°组>0°组>45°组;支撑密度0.70、0.90和1.10 mm下,不同构建角度组按RMSE值排序为45°组>90°组>0°组。在精密度方面,支撑密度0.50 mm下,不同构建角度组按RMSE值排序为90°组>0°组>45°组;支撑密度0.70 mm下,不同构建角度组按RMSE值排序为90°组>45°组>0°组;支撑密度0.90和1.10 mm下,不同构建角度组按RMSE值排序为45°组>90°组>0°组。结论不同构建角度和支撑密度对CoCr合金卡环准确性的影响不同。构建角度0°、支撑密度0.90 mm条件下卡环的准确性更高,值得临床和技工室推荐应用。

Objective To evaluate the accuracy of selective laser melting of cobalt-chromium(CoCr)clasps with different build angles and support densities.Methods The 3D software constructed a sample clasp(reference object)with an undercut depth of 0.50 mm,which was then imported to a metal 3D printer to form CoCr clasps at different build angles(0°,45°,and 90°)and support densities(0.50,0.70,0.90,and 1.10 mm).A model scanner was used to obtain scans of all clasps(test objects);the test objects were aligned with the reference object and test subjects were aligned with each other through a best-fit alignment method using Geomagic software to obtain root mean square error(RMSE)values for the accuracy of the clasps.The data were statistically analyzed using one-way analysis of variance or non-parametric rank sum test(α=0.05).Results In terms of trueness,the different build angle groups with support density of 0.50 mm were ranked by RMSE values as follows:90°group>0°group>45°group.For the different build angle groups with support densities of 0.70,0.90,and 1.10 mm,the RMSE values ranked as follows:45°group>90°group>0°group.In terms of precision,the different build angle groups with support density of 0.50 mm were ranked by RMSE values as follows:90°group>0°group>45°group.For support density of 0.70 mm,the ranking was 90°group>45°group>0°group,while for support densities of 0.90 and 1.10 mm,the ranking was 45°group>90°group>0°group.Conclusion The accuracy of CoCr clasps varies with the build angle and support density.However,clasps produced at a build angle of 0°and a support density of 0.90 mm exhibit higher accuracy and are recommended for use in clinical and technical laboratories.