Kupprano Peerakan, Kamonkhantikul Krid, Homsiang Woraporn, Takahashi Hidekazu, Arksornnukit Mansuang
Department of Prosthodontics, Faculty of Dentistry, Chulalongkorn University, Pathumwan, Bangkok, 10330, Thailand.
Department of Family and Community Dentistry, Faculty of Dentistry, Chiang Mai University, Suthep, Chiang Mai, 50200, Thailand.
BMC Oral Health. 2024 Dec 30;24(1):1572. doi: 10.1186/s12903-024-05373-5.
The selection guideline for the implant-supported bar connectors (ISBC) of hybrid denture is lacking. This study investigated the maximum von Mises stress (vMS), stress distribution, and displacement of various geometric ISBC in mandibular hybrid dentures, as well as the maximum principal stress (σmax) in the acrylic resin part, through finite element analysis.
Four different geometric cross-sectional patterns for mandibular ISBC-L, Y, I, and Square-of equal volume, based on the "All-on-4" concept, were created. Titanium alloy was used for ISBC with an acrylic resin wraparound. Models were integrated into the software and loading simulations mimicking mastication forces on posterior teeth in centric and eccentric loadings were performed. vMS was used for ISBC assessment, and σmax was assessed in acrylic resin.
In centric loading, vMS was mainly at the distal screw channel across most ISBCs. Y ISBC showed the least vMS, while I and Square ISBC demonstrated uniform stress distribution on both sides; load and non-load-bearing sides. The others showed concentrated vMS only on the load-bearing side. Square ISBC exhibited the most displacement. In the acrylic resin region of each, σmax was found concentrated around the contact point between two adjacent denture teeth at different locations, with Square showing the highest σmax. Under eccentric loading, the maximum vMS of each model was found at the interface between the distal screw channel and the lingual aspect of the abutment, with comparable vMS. Square ISBC experienced the most significant displacement and showed the highest σmax within the acrylic resin juxtaposed with the screw channel.
The Y model of titanium-alloy in mandibular ISBC demonstrated the lowest vMS and displacement.
混合义齿种植体支持杆连接器（ISBC）的选择指南尚不完善。本研究通过有限元分析，研究了下颌混合义齿中各种几何形状的ISBC的最大米塞斯应力（vMS）、应力分布和位移，以及丙烯酸树脂部分的最大主应力（σmax）。
基于“All-on-4”概念，创建了四种不同几何横截面模式的下颌ISBC——L形、Y形、I形和方形，且体积相等。ISBC采用钛合金材质，并带有丙烯酸树脂包绕。将模型导入软件，并进行模拟咀嚼力的加载模拟，包括正中加载和非正中加载时后牙的受力情况。vMS用于评估ISBC，σmax用于评估丙烯酸树脂。
在正中加载时，大多数ISBC的vMS主要集中在远端螺钉通道处。Y形ISBC的vMS最小，而I形和方形ISBC在两侧（负载侧和非负载侧）均表现出均匀的应力分布；其他形状的ISBC仅在负载侧表现出集中的vMS。方形ISBC的位移最大。在每种形状的丙烯酸树脂区域，σmax集中在不同位置的两个相邻义齿牙齿之间的接触点周围，方形的σmax最高。在非正中加载时，每个模型的最大vMS出现在远端螺钉通道与基牙舌侧的界面处，vMS相当。方形ISBC的位移最为显著，且在与螺钉通道相邻的丙烯酸树脂内表现出最高的σmax。
下颌ISBC中钛合金材质的Y形模型表现出最低的vMS和位移。
