Investigation of the influence of design details on short implant biomechanics using colorimetric photoelastic analysis: a pilot study

Introduction : The clinical survival of a dental implant is directly related to its biomechanical behavior. Since short implants present lower bone/implant contact area, their design may be more critical to stress distribution to surrounding tissues. Photoelastic analysis is a biomechanical method that uses either simple qualitative results or complex calculations for the acquisition of quantitative data. In order to simplify data acquisition, we performed a pilot study to demonstrate the investigation of biomechanics via correlation of the findings of colorimetric photoelastic analysis (stress transition areas; STAs) of design details between two types of short dental implants under axial loads. Methods Implants were embedded in a soft photoelastic resin and axially loaded with 10 and 20 N of force. Implant design features were correlated with the STAs (mm2) of the colored fringes of colorimetric photoelastic analysis. Results Under a 10 N load, the surface area of the implants was directly related to STA, whereas under a 20 N load, the surface area and thread height were inversely related to STA. Conclusion A smaller external thread height seemed to improve the biomechanical performance of the short implants investigated.

引言：牙科种植体的临床存活率与其生物力学表现直接相关。由于短种植体的骨-种植体接触面积更小，其设计对于应力向周围组织的分布影响可能更为关键。光弹性分析是一种生物力学研究方法，既可获取简单的定性结果，也可通过复杂计算得到定量数据。为简化数据采集流程，本研究开展了一项预试验，旨在通过比对轴向载荷下两种短牙科种植体的设计细节与比色光弹性分析所得应力过渡区域（stress transition areas, STAs）结果，探究其生物力学特性。
方法：将种植体包埋于软性光弹性树脂中，分别施加10 N与20 N的轴向载荷。将种植体的设计特征与比色光弹性分析所得彩色条纹的应力过渡区域面积（mm²）进行相关性分析。
结果：在10 N载荷条件下，种植体的表面积与应力过渡区域面积呈正相关；而在20 N载荷条件下，种植体的表面积与螺纹高度均与应力过渡区域面积呈负相关。
结论：本研究所涉及的短种植体中，较小的外螺纹高度似乎可改善其生物力学性能。