镍铬合金、钴铬合金和纯钛金瓷结合强度的比较

目的比较镍铬合金、钴铬合金和纯钛的金瓷结合强度和金瓷界面特征。方法执行ISO9693[1]标准,采用三点弯曲试验分别测定在常规热处理条件下的镍铬合金、钴铬合金和纯钛的金瓷结合强度。运用扫描电镜和X射线衍射进行金瓷界面分析。结果金瓷结合强度分别为:镍铬合金:(37.56±2.92)Mpa,钴铬合金:(39.06±2.79)Mpa,纯钛:(32.61±5.62)Mpa,前两者组间差异无统计学意义(P>0.05),后者与前两者组间差异有统计学意义(P<0.05)。扫描电镜和X线衍射:镍铬合金和钴铬合金与瓷之间紧密接触,无裂纹,界面过渡层15～20μm。纯钛与瓷过渡层80μm,可见孔洞。纯钛基体表面可见约2μm黑色带。结论①钴铬合金与镍铬合金的金瓷结合强度接近,都大于纯钛的金瓷结合强度。②钴铬合金、镍铬合金、纯钛的金瓷结合强度都大于25Mpa,按ISO9693标准均可应用于临床。③金瓷之间存在结合介质,形成过渡层。

Metal-ceramic bonding strength comparison among the Ni-Cr alloy Co-Cr alloy and pure titanium

Objective To compare the metal-ceramic bonding strength and the interfacial characteristic of Ni-Cr alloy,Co-Cr alloy and pure titanium.Methods Thirty wax patterns having dimensions 25mm×3.0mm×0.5mm were prepared by a metal mold.Metal-ceramic specimens were fabricated with three types of metal-ceramic alloys,10 for each type of alloy.All samples were prepared by the clinical empirical heat treatment.Ceramco Ⅲ porcelain cement was fused and adhered to Ni-Cr alloy and Co-Cr alloy while Willi Geller porcelain cement to the pure titanium.The metal-ceramic bonding strengths were evaluated using a three-point bending test according to ISO9693[1].Two more specimens of each group were made to observe the metal-ceramic interface through scanning electronic microscope（SEM）and energy dispersive spectrum（EDS）.The bonding strength data was analyzed using ANOVA and Bonferroni＇s test by SPSS16.0.Results The mean value of bonding strengths of three alloys were（37.56±2.92）Mpa（Ni-Cr alloy）,（39.06±2.79）Mpa（Co-Cr alloy） and（32.61±5.62）Mpa（pure titanium）.The first two alloys（P0.05）,whereas both of them had a statistical significance compared with the last one（P0.05）.SEM demonstrated that the bonding surface of Ni-Cr alloy and Co-Cr alloy were compacted and had no cracks.The width of interfacial transition layer was 15～20μm.The width of interfacial transition layer of pure titanium was 80μm.Many defects and 2μm of black belt were seen.Conclusion According to the test results,the metal-ceramic bonding strengths of Ni-Cr alloy and Co-Cr alloy are close each other,which are greater than that of pure titanium.The bonding strength of all metal-porcelain systems are within the acceptable levels by ISO9693 standard（25Mpa）.The bonding medium exists between metal and ceramic,and a transition layer was f and the layer is formed between them.