铸造和激光熔融钴铬合金与瓷结合强度的比较

Comparison of the bond strength of selective laser melting and cast Cobalt-Chromium alloys to porcelain

目的研究传统铸造技术和选择性激光熔融(SLM)技术制作的钴铬合金与瓷的结合强度的差异。方法分别使用失蜡铸造法和SLM制作钴铬合金试件(25 mm×3 mm×0.5 mm),在试件表面中心区域熔附8 mm×3 mm×1.1 mm的瓷,使用ISO 9693规定的三点弯曲测试对金瓷试件进行金瓷结合强度测定。使用佩有X线能谱分析的扫描电镜观察试件的显微特征、元素成分、开裂试件开裂模式及残留瓷面积分数,使用金相显微镜观察合金试件金相结构。结合强度、残留瓷面积分数数据使用独立样本t检验进行统计学分析(α=0.05)。结果铸造组金瓷结合强度为(32.93±4.33)MPa,激光熔融组金瓷结合强度为(32.41±3.21)MPa。两组间结合强度差异没有统计学意义(t=0.095,P=0.163),所有试件都为混合失败模式。残留瓷面积分数的定量结果为铸造组62.73±7.34,激光熔融组79.67±3.92,差异有统计学意义(t=-6.46,P<0.001)。激光熔融组比铸造组有更多的瓷残留。结论传统铸造法和SLM技术制作的钴铬合金金瓷结合强度无差异,在瓷黏附方面SLM技术优于铸造技术。

Objective To compare the bond strength of selective laser melting（SLM）and cast Cobalt-Chromium（Co-Cr）alloys to porcelain. Methods Co-Cr alloy specimens（25 mm × 3 mm × 0.5 mm）were prepared using either a cast or CAD/CAM SLM methods. A 8 mm × 3 mm × 1.1 mm ceramic layer was fused to the central portion（8 mm × 3 mm）of the surface of the metal specimens. The bond strengths of the metal-ceramic were tested using a three-point bending test according to the ISO 9693 standard.Scanning electron microscopy and energy dispersive spectroscopy were used to determine the morphology,elemental composition,failure types,and area fraction of adherence porcelain. Metallographic microscope was used to observe the metallurgical structure of alloy specimens. The data of metal ceramic bond strength and area fraction of adherence porcelain were analyzed using independent sample t-test（α = 0.05）.Results The metal-ceramic bond strength of SLM and cast Co-Cr alloy were（32.41 ± 3.21）and（32.93 ±4.33）MPa,respectively. No statistical difference was found between two groups（t = 0.095,P = 0.163）.After three-point bending test a mixture of adhesive and cohesive failure types was observed in all specimens. The area fraction of adherence porcelain of SLM and cast Co-Cr alloy was（79.67 ± 3.92）and（62.73 ± 7.34）,respectively. Significant differences were found between two groups（t =-6.46,P〈0.001）,suggesting that the SLM alloy surface had larger area of residual ceramic. Conclusions Nodifference was found in the metal-ceramic bond strength between SLM and cast Co-Cr alloy. In terms of theporcelain-bonding area,SLM alloys even had a greater advantage than cast alloys.