Akbarzadeh Ayshin, Hemmati Yasser, Saleh-Saber Fariba
Department of Prosthodontics, Dental Faculty, Urmia University of Medical Science, Urmia, Iran.
Department of Prosthodontics, Dental Faculty, Tabriz University of Medical Science, Tabriz, Iran.
Dent Res J (Isfahan). 2021 Dec 10;18:108. eCollection 2021.
The present study aimed to evaluate the stress distribution of porous tantalum implant and titanium solid implant assisted overdenture (IAO) in mandibular bone by utilizing three-dimensional (3D) finite element (FE) analysis.
In this FE study, an existing cone-beam volumetric tomography scan of a patient without any maxillofacial anomaly with an available acceptable IAO for mandible was used to attain the compartments of a completely edentulous mandible. Zimmer trabecular implants and locator attachment systems were selected as the case group (Model B), and Zimmer Screw-Vent implants and locator attachment system were chosen for the control (Model A), as overdenture attachments in the present study. The mandibular overdenture was scanned and digitized as a FE model. Two 3D FE models were designed as edentulous lower jaws, each with four implants in the anterior section of the mandible. Three forms of loads were directed to the IAO in each model: Vertical loads on the left first molar vertical molar (VM). Vertical loads on the lower incisors (VI). Inclined force buccolingually applied at left first molar (IM).
Under all loading conditions, the maximum strain values in peri-implant bone in Model A were less than Model B. Under VI, the greatest stress value around abutments in both models was about 2-3 times higher than the other loads. Under VM and IM loads, no significant difference was observed between models.
Using trabecular metal implants instead of solid implants reduces strain values around both cortical and trabecular bone.
本研究旨在通过三维（3D）有限元（FE）分析评估多孔钽植入物和钛实心植入物辅助覆盖义齿（IAO）在下颌骨中的应力分布。
在本有限元研究中，使用一名无任何颌面异常且下颌有可用且可接受的IAO的患者现有的锥束容积断层扫描来获取完全无牙下颌的各部分。选择 Zimmer 小梁植入物和定位器附着系统作为病例组（模型B），选择 Zimmer 螺旋通风口植入物和定位器附着系统作为对照组（模型A），作为本研究中的覆盖义齿附着体。对下颌覆盖义齿进行扫描并数字化为有限元模型。将两个3D有限元模型设计为无牙下颌，每个在下颌前部有四个植入物。在每个模型中，对IAO施加三种形式的载荷：左侧第一磨牙垂直向载荷（VM）。下切牙垂直向载荷（VI）。在左侧第一磨牙颊舌向施加的斜向力（IM）。
在所有加载条件下，模型A中种植体周围骨的最大应变值小于模型B。在VI载荷下，两个模型中基牙周围的最大应力值比其他载荷高约2 - 3倍。在VM和IM载荷下，模型之间未观察到显著差异。
使用小梁金属植入物而非实心植入物可降低皮质骨和小梁骨周围的应变值。
