牙龈卟啉菌381对纯钛及钛75合金种植体表面失泽的腐蚀

Tarnish induced by Porphyromonas gingivalis 381 on implant denture surface of titanium and Ti-75 alloy

目的 研究牙龈卟啉菌 381对纯钛及钛 75合金种植体表面失泽腐蚀 .方法 将纯钛 (TA 2 )、钛 75合金机加工成10 mm× 10 m m× 1m m板片 ,数量分别为 30片和 6 0片 ,取钛75合金试件 30片与纯钛试件分别进行化学钝化处理 .将每组试件 30片随机分空白对照组、培养基对照组、实验组各 10片 .厌氧环境中将牙龈卟啉菌 381接种到改良 GAM培养基上 ,将试件贴附表面 ,每周转换传递 1次 ,共 10 wk. 0 .5 m L· L- 1戊二醛消灭细菌 ,清洗 ,2 wk后 ,用 MINOL TA CR- 10 0型色度计观察 .结果 肉眼观察纯钛 (钝化 )、钛 75合金 (钝化、非钝化 )实验组试件表面颜色由银灰色变成淡黄色 .Bartlett方差齐性检验知纯钛 (钝化 )、钛 75合金 (钝化 )和钛75合金 (非钝化 )的空白对照组与培养基对照组的 L* ,a* ,b*值无显著差异 (P>0 .0 5 ) ;纯钛 (钝化 )、钛 75合金 (钝化 )、钛75合金 (非钝化 )的实验组分别与空白组、培养基组的 L,a,b值有明显差异 (P<0 .0 5 ) .结论 牙龈卟啉菌 381对纯钛 (钝化 )、钛 75合金 (钝化、非钝化 )发生肉眼可见的表面失泽 ,且不受钛 75合金表面钝化膜形成方式不同影响 .色度计分析知三种类型试件表面颜色由绿黄区域向红黄区域移动 .

AIM To study the tarnish induced by Porphyromonas gingivalis 381 on implant denture surface of titanium and Ti 75 alloy.METHODS Pure titanium and Ti 75 alloy were machined into 90 tablets of 10 mm×10 mm×1 mm (30 of pure titanium; 60 of Ti 75 alloy). 30 specimens sampled randomly from Ti 75 alloy and 30 specimens of pure titanium were subjected to chemical passivation treatment. The 30 specimens of pure titanium, depassivated Ti 75 alloy and passivated Ti 75 alloy were randomly divided into three groups (blank control group, media control group and inoculated media group) respectively, each containing 10 specimens. Under the anaerobic condition, the surfaces of the modified GAM media were inoculated with Porphyromonas ginyiualis(Pg381). The labeled specimens' surfaces were then aseptically placed on top of the media surface for 10 weeks, with one generation time per week. The specimens were removed after 10 weeks of incubation, immersed in 0.5 mL·L -1 glutaradehyde solution to eliminate Porphyromonas gingivalis 381 and rinsed with distilled water. 2 weeks later, specimens were removed and observed visually or examined by MINOLTA CR 100 color apparatus. RESULTS Visual evaluation: Porphyromonas gingivalis 381 caused significant tarnish on specimens exposed to inoculated media. All the specimens' surface changed into yellow color and surface gloss did not exist. Color apparatus evaluation: compared with the blank control, media control didn't have any influence on the specimens' L*a*b* values ( P >0.05). Porphyromonas gingivalis 381 caused significant tarnish on specimens exposed to inoculated media, indicating that there was a significant difference between media control group and blank control group with inoculated media group on all the specimens' L*a*b* values ( P <0.05).CONCLUSION Porphyromonas gingivalis 381 caused significant and visible tarnish (observable by naked eyes and color apparatus) on pure titanium, depassivated Ti 75 alloy and passivated Ti 75 alloy. The CIE1976L*a*b* color system reading indicates that the color of titanium and Ti 75 alloy changed to from yellow green to red yellow.