表面粗化处理不均衡螺纹钛人工牙种植体的疲劳性能研究

Study on the fatigue performance of the uneven-threaded titanium dental implants treated by surface roughening

目的探讨钛颗粒喷砂+混合酸热处理粗化方法及不同颈部结构对种植体疲劳性能的影响。方法构建五种不同颈部结构及表面的钛种植体(均衡螺纹组、宽颈组、颈部单头微螺纹组、颈部双头微螺纹组、表面粗化及颈部双头微螺纹组),采用SEM观察、动态循环疲劳试验,分析各组种植体的疲劳性能。结果 SEM观察:Ma表面较平整,有大量方向一致、规则、浅沟纹状的切削条痕,局部散在点状凹陷及凸起。SLA表面整洁、粗糙均匀,不规则的表面上有大量大小不一的凹陷约为5~30um,边缘锐利,部分融合,偶尔可见散在的微裂隙,在大的凹陷内还可见形状不规则的小凹坑约为200~500nm,深浅不一;达到5×10~6循环的极限载荷:均衡螺纹组为250N(137.50Ncm),宽颈组、颈部单头微螺纹组、颈部双头微螺纹组均为300N(165.00Ncm),表面粗化及颈部双头微螺纹组为275N(151.25Ncm);五组种植体在250N载荷下,同时达到5×10~6循环时,对应的位移(mm)分别为0.391、0.255、0.257、0.258、0.272。结论宽颈、颈部单头微螺纹及颈部双头微螺种植体疲劳耐受性能相似,均高于均衡螺纹;SLA表面较Ma表面的疲劳性能有所降低,但均能满足临床要求。

Objective To explore the effects of particle blast combined with heated acid etching and uneven- threaded neck structures on the fatigue characteristics of the implants. Methods Five titanium implants with different neck structure and surfaces were established. They are uniform-threaded implant （UT）, wide-neck implant （WN）, implant with single-microthreaded neck （SMN）, implant with double-microthreaded neck （DMN）, and implant with roughened double-microthreaded neck （RDMN）. Scanning electron microscope （SEM） and dynamic fatigue test were used to analyze the fatigue characteristics of the implants. Results SEM observation： Ma surface was relatively smooth, with lots of regular and shallow groove-like cuttings of the same direction, but scattered with pits or heaves locally. SLA surface was neat and evenly roughened, with a large quantity of 5-30um pits of different sizes on the irregular surface. The pits are sharp-edged with partial fuse and occasionally seen scattered micro cracks. In the big pits, 200-500nm irregular small pits with different depth were also observed. The limit load of 5-106 cycle was 250N （137.50Ncm） for UT, 300N（165.00Ncm）for WN, SMN, and DMN, and 275N （151.25Ncm） for RDMN. Under the load of 250N, when the five implants reached the cycle of 5×10^6, the displacement was 0.391mm, 0.255mm, 0.257mm, 0.258mm, and 0.272mm for UT, WN, SMN, DMN, and RDMN respectively. Conclusion WN,SMN and DMN have similar fatigue tolerance, both higher than UT. The fatigue tolerance was lower in SLA surface compared to Ma surface, but both can meet the clinical needs.