激光快速成形技术制作镍铬合金基底冠的实验研究

Experimental study on fabricating Ni-Cr alloy coping with laser rapid forming

目的研究激光快速成形技术制作镍铬合金基底冠的可行性。方法利用逆向工程和计算机辅助设计技术设计基底冠，应用激光快速成形技术制作镍铬合金基底冠，分别测量基牙预备体代型外表面胎面边缘（A组）、轴面中点（B组）和肩台边缘处（C组）与镍铬合金基底冠内表面的间隙，与临床可接受的标准（120μm）进行单样本t检验。结果A、B、C组间隙值分别为（82．60±13．58）、（45．80±16．12）、（57．90±9．04）μm，各组均小于120μm，差异均有统计学意义（tA=8．71，tB=14．56，tC=21．72，P〈0．05）。结论利用激光快速成形技术可加工出厚度为0．8mm、与基牙间隙低于120μm的镍铬合金基底冠。

Objective To probe the feasibility of fabricating Ni-Cr alloy coping with laser rapid forming（LRF）. Methods The digitalized model of coping was designed using the technology of reverse engineering and computer aided design（CAD） based on the abutment. The Ni-Cr alloy coping was fabricated with LRF. The gaps between the internal surface of coping and the external surface of abutment were measured respectively at the locations of occlusal surface edge, midpoint of axial wall and shoulder edge. The results were compared with the reference of 120 μm which was accepted generally to analyze the adaptation by statistical means. Results With statistical analysis of the t-test, the mean of gap width of each group, （82.60 ±13.58） μm for group A, （45.80 ± 16.12） μm for group B, and （57.90 ± 9.04） μm for group C, was less than 120 μm and the differences were statistically significant （tA = 8. 71, tB =14. 56, tC = 21. 72, P 〈0. 05 ）. Conclusions The Ni-Cr alloy coping with a thickness of 0.8mm can be fabricated with LRF successfully and the adaptation can meet the reference of 120 μm.