Department of Oral and Maxillofacial Surgery, 1st Faculty of Medicine, Charles University in Prague, U Nemocnice 2, 120 00, Prague, Czech Republic.
Department of Aircraft Strength, National Aerospace University, Kharkov, Ukraine.
Comput Biol Med. 2017 Dec 1;91:318-325. doi: 10.1016/j.compbiomed.2017.09.016. Epub 2017 Sep 22.
For dental implant success, experimentally established thresholds should limit bone stresses and strains. From these metrics, the ultimate functional load, which determines the implant load-carrying capacity, can be calculated. Obviously, its decrease due to bone loss shortens implant service life. A comparison of how bone loss affects the ultimate functional loads of various implants can provide the clinician with meaningful feedback concerning the suitability and longevity of implants. The aim of this study is to evaluate the lifetime of different dental implants placed in I-IV bone types on the basis of a comparison of their ultimate functional loads with consideration of the bone loss factor.
Von Mises stress and first principal strain distributions in bone-implant interface were studied and ultimate functional loads were calculated. Models of I-IV bone types were designed. 3.3 × 8.0 mm (A), 4.1 × 12.0 mm (B) and 4.8 × 14.0 mm (C) implants were analyzed at 10 levels of bone loss. Ultimate functional loads, which generated the ultimate von Mises stress and first principal strain in bone, were computed.
For the implants A, B, and C placed in type I bone, ultimate functional load values were above 120.92 N experimental functional load, which corresponded to 10+, 10+, and 10 + years of service with 0.2 mm annual bone loss. For type II bone, the lifetime was 4, 10+, and 10 + years. For type III bone, the lifetime was 4, 5, and 5 years. For type IV bone, first principal strains were initially deleterious for all implants.
In oral implantology, bone loss is an essential factor for implant longevity prognosis. While evaluating implant load-carrying capacity, clinicians should take into account the factor of implant longevity decrease.
对于牙种植体的成功，实验确定的阈值应限制骨的应力和应变。从这些指标中，可以计算出决定种植体承载能力的极限功能负荷。显然，由于骨量丢失导致的极限功能负荷的减少会缩短种植体的使用寿命。比较各种种植体的骨量丢失如何影响其极限功能负荷，可以为临床医生提供有关种植体适用性和寿命的有意义的反馈。本研究的目的是基于考虑骨丢失因素，比较不同种植体的极限功能负荷，评估不同类型骨中的各种种植体的使用寿命。
研究了骨-种植体界面处的 von Mises 应力和第一主应变分布，并计算了极限功能负荷。设计了 I-IV 型骨模型。分析了 10 个不同骨丢失水平的 3.3×8.0mm（A）、4.1×12.0mm（B）和 4.8×14.0mm（C）种植体。计算了在骨中产生极限 von Mises 应力和第一主应变的极限功能负荷。
对于放置在 I 型骨中的种植体 A、B 和 C，极限功能负荷值高于实验功能负荷 120.92N，分别对应于 0.2mm 年骨丢失量下的 10+、10+和 10+年的使用寿命。对于 II 型骨，使用寿命为 4、10+和 10+年。对于 III 型骨，使用寿命为 4、5 和 5 年。对于 IV 型骨，所有种植体的初始主应变都是有害的。
在口腔种植学中，骨丢失是影响种植体寿命预测的重要因素。在评估种植体承载能力时，临床医生应考虑到种植体寿命缩短的因素。
