Evaluation of the fit of cobalt-chromium crowns fabricated by selective laser melting / 实用口腔医学杂志

ABSTRACT

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-sionThe 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.