Int J Oral Maxillofac Implants. 2022 Jul-Aug;37(4):740-747. doi: 10.11607/jomi.9260.
Titanium-zirconium (Ti-Zr) alloy has been developed to strengthen the implant body, but clinically relevant information is still limited. The aim of this in vitro study was to compare the rotational load fatigue performance of implant-abutment connections in narrow-diameter (3.3-mm) and regular-diameter (4.1-mm) implants made with commercially pure grade 4 titanium alloy (CPTi-G4) and Ti-Zr.
Narrow-diameter (N) and regular-diameter (R) implants with CPTi-G4 (Ti) or Ti-Zr (Tz) materials were tested. This resulted in four test groups: NTi, NTz, RTi and RTz. Five specimens were made for each group (n = 5). Abutments used were milled from titanium-aluminum-niobium alloy abutment blanks. A rotational load fatigue machine applied a sinusoidally varying load at an angle of 45 degrees to produce an effective bending moment of 35 Ncm at a frequency of 14 Hz in air at 20°C. The number of cycles to failure was recorded. The upper limit was set as 5 million cycles. Results were evaluated using analysis of variance (ANOVA) and Tukey post hoc tests. Failure locations and patterns were evaluated with scanning electron microscope (SEM).
All regular-diameter test groups reached the upper limit of 5 million cycles without failure. All narrow-diameter test groups failed within the range of 402,530 cycles to 3,374,353 cycles. It could be observed that NTz showed a higher mean cycle count as compared to NTi. NTi test group recorded two implants damaged, one implant fracture, five abutment fractures, and four screw fractures. NTz test group showed only abutment fractures at the level of implant platform, with no damage to the implant bodies. Significant difference was found between implants of different diameters. There was no significant difference between implants of different materials.
Regular-diameter implants performed significantly better than narrow-diameter implants, regardless of material, while no significant difference in cyclic load to failure was found between groups of different alloys. All NTz failures were at the abutment only, without damage to the implant. This failure pattern can potentially be clinically advantageous in terms of retrieval and subsequent replacement of a failed prosthesis.
钛锆（Ti-Zr）合金的研发旨在增强种植体体部的强度，但目前相关的临床信息仍然有限。本体外研究的目的是比较窄径（3.3mm）和常规径（4.1mm）种植体-基台连接在承受旋转负载时的疲劳性能，这些种植体分别采用商用纯钛 4 级（CPTi-G4）和 Ti-Zr 制造。
分别采用商用纯钛 4 级（CPTi-G4）和 Ti-Zr（Tz）材料制作窄径（N）和常规径（R）种植体，由此形成 4 个测试组：NTi、NTz、RTi 和 RTz。每组制作 5 个试件（n=5）。基台由钛铝合金基台毛坯铣削而成。旋转负载疲劳机以 45 度角施加正弦变化的负载，在 20°C 的空气中以 14Hz 的频率产生 35Ncm 的有效弯矩。记录失效的循环次数。上限设定为 500 万次循环。使用方差分析（ANOVA）和 Tukey 事后检验对结果进行评估。使用扫描电子显微镜（SEM）评估失效位置和模式。
所有常规径测试组均在未失效的情况下达到了 500 万次循环的上限。所有窄径测试组的失效范围为 402530 次至 3374353 次循环。可以观察到，与 NTi 相比，NTz 的平均循环计数更高。NTi 测试组有 2 个种植体损坏、1 个种植体断裂、5 个基台断裂和 4 个螺丝断裂。NTz 测试组仅显示在种植体平台水平的基台断裂，种植体体部无损坏。不同直径的种植体之间存在显著差异。不同材料的种植体之间无显著差异。
无论材料如何，常规径种植体的表现明显优于窄径种植体，而不同合金组之间的循环负载至失效无显著差异。所有 Ntz 失效均仅发生在基台处，种植体无损坏。这种失效模式在临床上可能有利于取出和随后更换失败的假体。
