Gershov Sapir, Xie Jing, Shah Furqan A, Shemtov-Yona Keren, Rittel Daniel
Technion Autonomous Systems Program, Technion - Israel Institute of Technology, Haifa 32000, Israel.
State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China.
Acta Biomater. 2022 Dec;154:302-311. doi: 10.1016/j.actbio.2022.10.042. Epub 2022 Oct 25.
Dental implant stability is greatly affected by the mechanical properties of the bone-implant interface (BII), and it is key to long-term successful osseointegration. Implant stability is often evaluated using the Resonant Frequency Analysis (RFA) method, and also by the quality of this interface, namely the bone-implant contact (BIC). True to this day, there is a scarcity of models tying BIC, RFA and a spatially and mechanically evolving BII. In this paper, based on the contact/distance osteogenesis concept, a novel numerical spatio-temporal model of the implant, surrounding bone and evolving interface, was developed to assess the evolution of the interfacial stresses on the one hand and the corresponding resonant frequencies on the other. We postulate that, since the BIC percentage reaches saturation over a very short time, long before densification of the interface, it becomes irrelevant as to load transmission between the implant and the bone due to the existence of an open gap. Gap closure is the factor that provides continuity between the implant and the surrounding bone. The results of the calculated RFA evolution match and provide an explanation for the multiple clinical observations of a sharp initial decline in RFA, followed by a gradual increase and plateau formation. STATEMENT OF SIGNIFICANCE: A novel three-dimensional numerical model of an evolving bone-dental implant interface (BII) is presented. The spatio-temporal evolution of the bone-implant contact (BIC) and the BII, based on contact/distance (CO/DO) osteogenesis, is modeled. A central outcome is that, until BII maturation into a solid continuous bone (no open gap between CO-DO fronts), the bone-implant load transfer is hampered, irrespective of the BIC. The resonant frequencies' evolution of the jawbone-BII-implant is calculated to reproduce the well-established implant stability analysis based on the Resonant Frequency Analysis. The results resemble those reported clinically, and here too, the determinant transition occurs only after interfacial gap closure. Those results should motivate clinicians to re-consider structural continuity of the BII rather than the BIC only.
牙种植体稳定性受骨-种植体界面（BII）力学性能的显著影响，且是长期成功骨整合的关键。种植体稳定性通常采用共振频率分析（RFA）方法进行评估，也可通过该界面的质量，即骨-种植体接触（BIC）来评估。时至今日，将BIC、RFA与空间及力学上不断演变的BII联系起来的模型仍很匮乏。本文基于接触/距离成骨概念，开发了一种新颖的种植体、周围骨及演变界面的数值时空模型，以一方面评估界面应力的演变，另一方面评估相应的共振频率。我们推测，由于BIC百分比在极短时间内达到饱和，远在界面致密化之前，由于存在开放间隙，其对于种植体与骨之间的载荷传递就变得无关紧要了。间隙闭合是在种植体与周围骨之间提供连续性的因素。计算得到的RFA演变结果与多项临床观察结果相符，并为RFA最初急剧下降，随后逐渐上升并形成平台期的现象提供了解释。重要性声明：提出了一种新颖的骨-牙种植体界面（BII）演变的三维数值模型。基于接触/距离（CO/DO）成骨，对骨-种植体接触（BIC）和BII的时空演变进行了建模。一个核心结果是，在BII成熟为坚实连续的骨（CO-DO前沿之间无开放间隙）之前，无论BIC如何，骨-种植体载荷传递都会受到阻碍。计算了颌骨-BII-种植体的共振频率演变，以重现基于共振频率分析的成熟的种植体稳定性分析。结果与临床报道相似，同样，决定性转变仅在界面间隙闭合后发生。这些结果应促使临床医生重新考虑BII的结构连续性，而不仅仅是BIC。
