应用牙科X线机探测口腔金属修复体的内在缺陷

目的:探讨用牙科X线机探测钛、镍铬合金、钴铬合金铸件缺陷的可行性,同时分析金属铸件厚度对探测参数设置的影响。方法:按常规铸造方法制作3种厚度(1.0mm、0.6mm、0.3mm)的钛、镍铬合金、钴铬合金金属片,选用激光点焊机在金属表面打孔,模拟金属铸件铸造过程中产生的缺陷。调整牙科X线机各可调参数,在各参数下拍摄金属铸件照片,观察探伤结果。采用SPSS12统计软件包对数据进行组间t检验。结果:钛金属厚度对探伤参数设置的影响无统计学意义,P>0.05。镍铬合金和钴铬合金厚度对探伤参数设置的影响具有显著性差异,P<0.05。结论:钛金属铸件厚度对探伤参数设置的影响不大,可用牙科X线机代替专门的探伤机进行探测。

Non-invasive detection of metal casting defects using dental X ray machine

PURPOSE: The purpose of this in vitro study is to find the best parameters in detecting the casting defects made of titanium, nickel-chromium and chromium-cobalt using dental X ray machine. METHODS: Casting sheets in different thickness(1.0mm,0.6mm,0.3mm)were fabricated using of Ti, Ni-Cr and Cr-Co.Small pores on the surfaces were made with laser welder to simulate the internal porosity of the castings. Parameters of the dental X ray machine were adjusted to take films. The data were analyzed using SPSS12 software package for group t test. RESULTS: The thickness of Ti had no significant effect on the setting of the parameters of the dental X ray machine in detecting the defects of titanium castings (P>0.05),while the thickness of Ni-Cr and Cr-Co had significant effect on the setting of the parameters(P<0.05). CONCLUSION: Dental X ray machine can be used in detecting the defects of titanium casting sheets. Supported by Shanghai Leading Academic Discipline Project (T0202).