Aalaei Shima, Sheikhi Atefeh, Mehdian Parisa, Taghavi Farnoosh, Salimian Sara, Taghavi-Damghani Farnaz
Department of Prosthodontics, Dental Caries Prevention Research Center, Qazvin University of Medical Sciences, Qazvin, Iran.
Student Research Committee, Qazvin University of Medical Sciences, Qazvin, Iran.
J Dent Res Dent Clin Dent Prospects. 2023 Fall;17(4):222-226. doi: 10.34172/joddd.2023.40483. Epub 2023 Dec 30.
The objective of the current research was to evaluate how stress is distributed in the peri-implant bone of a mandibular overdenture with implants placed asymmetrically to the midline.
A 26-year-old male's mandible, with missing teeth, was examined using computed tomography (CT) scanning. Two implants were inserted at right angles to the occlusal plane, in the positions of the right canine and left lateral incisor of the mandible, with an internal connection. Two types of attachments (bar and ball) were designed. To simulate the clinical condition, anterior (on central incisors) and bilateral posterior (on premolars and molars) loadings were applied. The stress distribution was assessed using finite element analysis (FEA).
The lateral incisor level implant was found to have the highest maximum principal stress (about 33 MPa) in both models in the anterior loading condition. However, in both models, the canine-level implant revealed more stress values (about 22 MPa) in the posterior loading condition.
In mandibular implant-supported overdentures, when implants were placed asymmetrically to the midline, one acted as a fulcrum and sustained more occlusal load. The bar attachment system did not reveal superior results in terms of stress distribution compared to the ball attachment.
当前研究的目的是评估在下颌覆盖义齿中,种植体不对称于中线植入时,种植体周围骨组织的应力分布情况。
对一名26岁缺失牙男性的下颌骨进行计算机断层扫描(CT)检查。在下颌右侧尖牙和左侧侧切牙位置,与咬合平面呈直角植入两颗具有内部连接的种植体。设计了两种附着体(杆式和球式)。为模拟临床情况,施加前牙(中央切牙处)和双侧后牙(前磨牙和磨牙处)载荷。使用有限元分析(FEA)评估应力分布。
在前牙加载条件下,两种模型中侧切牙水平的种植体均发现具有最高的最大主应力(约33兆帕)。然而,在两种模型中,后牙加载条件下尖牙水平的种植体显示出更多的应力值(约22兆帕)。
在下颌种植体支持的覆盖义齿中,当种植体不对称于中线植入时,其中一颗种植体充当支点并承受更多的咬合载荷。与球式附着体相比,杆式附着体系统在应力分布方面未显示出更优的结果。