Influence of the nanometric surface topography on the primary stability of dental mini-implants

Abstract Introduction The physical-chemical modification of the surface of mini-implants used in the support of overdentures can influence the mechanical performance and survival of the same. Objective To evaluate the influence of a nanometric surface treatment on the mechanical performance of new mini-implant designs. Material and method 40 mini-implants (Ti-6Al-4V) with Ø 2 mm x 10 mm in length and two different designs, threaded and helical, were divided into four groups (n = 10) according to model, presence or absence of surface treatment. The mechanical performance was evaluated by means of insertion torque and pullout test in swine bony cylinders. Analysis of variance ANOVA and Tukey test, with significance of 5% were used for statistical analysis of the data. Result A statistically significant difference was observed between the groups with and without treatment for insertion torque (p <0.001) and pullout test (p = 0.006), being the highest mean for the treatment group, regardless of the design. In the comparison between the designs, the thread presented a significantly higher average (p <0.001) than the helicoid. Conclusion The nanometric surface treatment enabled better mechanical performance of the mini-implants evaluated. With respect to the new designs tested, the thread presented superior results to the helicoidal one.

【摘要】
引言：用于支持覆盖义齿（overdenture）的微型种植体（mini-implant）表面的理化改性，可对其力学性能与留存率产生影响。
目的：评估纳米表面处理（nanometric surface treatment）对新型微型种植体设计力学性能的影响。
材料与方法：选取40枚直径2mm、长度10mm的Ti-6Al-4V微型种植体，包含螺纹型（threaded）与螺旋型（helical）两种不同设计，按种植体类型及是否进行表面处理分为4组（每组n=10）。采用植入扭矩（insertion torque）测试与猪骨圆柱试件拔出试验（pullout test）评估其力学性能；数据统计分析采用方差分析（Analysis of Variance, ANOVA）与Tukey检验，检验水准设为5%。
结果：无论种植体设计类型如何，经表面处理组的植入扭矩与拔出试验结果均显著高于未处理组（植入扭矩：p<0.001；拔出试验：p=0.006），组间差异具有统计学意义。在两种设计的对比中，螺纹型种植体的力学性能均值显著高于螺旋型（p<0.001）。
结论：纳米表面处理可提升受试微型种植体的力学性能；在所测试的新型种植体设计中，螺纹型的表现优于螺旋型。