Pérez R A, Gargallo J, Altuna P, Herrero-Climent M, Gil F J
Bioengineering Institute of Technology, Universitat Internacional de Catalunya. C/ Josep Trueta s/n. Sant Cugat del Valles, 08195 Barcelona, Spain.
Faculty of Dentistry, Universitat Internacional de Catalunya, C/ Josep Trueta s/n. Sant Cugat del Valles, 08195 Barcelona, Spain.
Materials (Basel). 2020 Mar 20;13(6):1429. doi: 10.3390/ma13061429.
The use of narrow titanium dental implants (NDI) for small ridges, reduced interdental space, or missing lateral incisors can be a viable option when compared to the conventional wider dental implants. Furthermore, in many cases, standard diameter implant placement may not be possible without grafting procedures, which increases the healing time, cost, and morbidity. The aim of this study was to analyze the mechanical viability of the current narrow implants and how narrow implants can be improved. Different commercially available implants (n = 150) were tested to determine maximum strength, strain to fracture, microhardness, residual stress, and fatigue obtaining the stress-number of cycles to fracture (SN) curve. Fractography was studied by scanning electron microscopy. The results showed that when the titanium was hardened by the addition of 15% of Zr or 12% cold worked, the fatigue limit was higher than the commercially pure grade 4 Ti without hardening treatment. Grade 4 titanium without hardening treatment in narrow dental implants can present fractures by fatigue. These narrow implants are subjected to high mechanical stresses and the mechanical properties of titanium do not meet the minimal requirements, which lead to frequent fractures. New hardening treatments allow for the mechanical limitations of conventional narrow implants to be overcome in dynamic conditions. These hardening treatments allow for the design of narrow dental implants with enhanced fatigue life and long-term behavior.
与传统的较宽牙科植入物相比，使用窄钛牙科植入物（NDI）来修复小牙槽嵴、减小牙间隙或修复侧切牙缺失可能是一种可行的选择。此外，在许多情况下，如果不进行植骨手术，可能无法植入标准直径的植入物，这会增加愈合时间、成本和发病率。本研究的目的是分析当前窄植入物的机械可行性以及如何改进窄植入物。对不同的市售植入物（n = 150）进行测试，以确定其最大强度、断裂应变、显微硬度、残余应力和疲劳性能，从而获得应力-断裂循环次数（SN）曲线。通过扫描电子显微镜研究断口形貌。结果表明，当通过添加15%的Zr或进行12%的冷加工使钛硬化时，其疲劳极限高于未经硬化处理的商业纯4级钛。窄牙科植入物中未经硬化处理的4级钛可能会因疲劳而出现骨折。这些窄植入物承受着高机械应力，而钛的机械性能不符合最低要求，这导致频繁骨折。新的硬化处理能够在动态条件下克服传统窄植入物的机械局限性。这些硬化处理有助于设计出具有更长疲劳寿命和长期性能的窄牙科植入物。
