选择性激光熔覆(SLM)制作钴铬合金冠的适合性研究

Evaluation of the fit of cobalt-chromium crowns fabricated by selective laser melting

目的:评价选择性激光熔覆(SLM)技术与失蜡铸造法制作的钴铬合金单冠与三联冠的适合性。方法:采用2种SLM系统EOS M270与EOS M280及铸造法分别制作钴铬合金单冠与三联冠各5个,通过采用硅橡胶法在体式显微镜下测量边缘及内部垂直间隙。采用SPSS 17.0软件对实验数据进行单因素方差分析。结果:钴铬合金单冠的边缘间隙和内部间隙(μm)分别为:EOS M270组42.28±11.58、125.75±47.67,EOS M280组46.54±8.4、128.22±54.18,铸造组为48.66±12.08、135.37±46.89。三联冠的边缘间隙(μm)和内部间隙(μm)分别为:EOS M270组40.55±10.04、133.09±39.80,EOS M280组45.36±10、138.94±50.61,铸造组为54.24±12.04、151.87±61.94(P<0.05)。结论:SLM组边缘平均垂直间隙明显小于临床普遍接受的120μm的标准,精度可以满足临床要求。SLM钴铬合金单冠的边缘适合性优于铸造法,内部适合性无统计学差异。SLM钴铬合金三联冠的边缘适合性及内部适合性均优于铸造法。

Objective：To compare the adaption of cobalt-chromium prostheses fabricated by selective laser melting（SLM）and conven-tional lost wax technique（LW）method.Methods：Cobalt-chromium crowns and three-unit fixed dental prostheses（FDPs）were fabrica-ted by selective laser melting（SLM）or by conventional lost wax technique（LW）respectively（n =5）.Marginal fit and internal fit were examined using a light-body silicone.After setting,each silicon film was cut into 2 parts and the thickness of silicon layer was measured at 1 00 ×magnification using a digital microscope,the data of marginal gap（MG）and internal gap（IG）were statistically analysed by ANOVA and SPSS statistical package version 1 7.0.Results：The MG and IG（μm）of cobalt-chromium alloy crowns in EOS M270 group were 42.28 ±1 1 .58 and 1 25.75 ±47.67,in EOS M280 group 46.54 ±8.4 and 1 28.22 ±54.1 8,in LW group 48.66 ±1 2.08 and 1 35.37 ±46.89.The MG and IG（μm）of three-unit FDPs in EOS M270 group were 40.55 ±1 0.04 and 1 33.09 ±39.80,in EOS M280 group 45.36 ±1 0 and 1 38.94 ±50.61 ,in LW group 54.24 ±1 2.04 and 1 51 .87 ±61 .94（P〈0.05）,respectively.Conclu-sion：The marginal fit of the SLMgroup is superior to that of the LW group and significantly smaller than 1 20 μm of clinical generally accepted standards.SLMsystem can satisfy the clinical requirements.