钛及钛合金种植体的两种表面处理对细菌黏附能力的影响

Titanium and titanium alloy implants:influence of two different surface modifications on bacterial adherence

目的研究两种表面处理(等离子渗氮和物理气相沉积TiN涂层)对钛、钛合金表面的组织结构、性能及对变形链球菌黏附的影响。方法将相同规格的钛、钛合金片经逐级抛光后分别随机分成3组,每组3片,依次为抛光组,渗氮表面处理组,TiN涂层表面处理组。以抛光钛、钛合金组作为对照。测量所有试件表面的粗糙度值,并采用扫描电镜、Axiovert 25CA光学图像分析仪及GDA750对钛、钛合金表面渗镀层的表面形态进行分析;将材料接种于变形链球菌悬液,在荧光显微镜下计数黏附细菌的数量。结果两种表面处理仅使原有表面粗糙度略微增加;扫描电镜显示两种表面处理后材料表面的原始划痕消失;GDS检测分析结果表明:钛、钛合金两种表面处理后,表面主要由氮化钛化合物组成。经两种处理后,钛、钛合金黏附细菌的量显著减少,而两种表面处理差异无统计学意义。结论钛、钛合金经两种表面处理后形成了稳定的改性层,且能减少细菌的黏附。相对于有涂层脱落之忧的物理气相沉积TiN涂层技术,等离子渗氮技术有望作为种植体穿龈部和种植体基台部的表面处理技术。

Objective To investigate the impacts of two different surface modifications for titanium and titanium alloys on the surface structure, property and adhesion of Streptococcus mutans as compared with control surfaces. Methods Standard-sized polished commercially pure titanium and titanium alloy discs were randomized into three groups （n=3 each）. One group was modified using plasma nitriding technique, another treated with physical vapour deposition （PVD coating） and titanium nitride （TIN） technique, while the remaining were used as controls. The observations were performed with a scanning electron microscope （SEM）, and estimation of surface roughness was done by a profilometer. The metallograph was analyzed with an Axiovert 25CA system. In addition, variations in element distribution along cross-section of surface modified layer were studied with GDA750. Titanium and titanium alloys were incu- bated in Streptococcus mutans suspension, photographed and counted for adhering bacteria with acridine orange staining under fluorescence microscopy. Results Two surface treatments led to modest increase in roughness of the surfaces. SEM showed disappearing of microgrooves caused by polish on each surface after modifications. The results of GDS showed that the modified surface layers were composed of titanium nitride. A significant reduction in the number of adhering bacteria was observed on modified titanium and its alloy, whereas no statistical significance was found between the two surface treatments. Conclusion The two modification treatments produced stable layers on titanium and titanium alloy surfaces with reduced bacterial adherence. In comparison with PVD coating which has a risk of the coating detachment, plasma nitriding may be more suitable for use as surface treatment technique for the transgingival and abutment part of an implant.