Memari Yeganeh, Geramy Allahyar, Fayaz Amir, Rezvani Habib Abadi Shirin, Mansouri Yasaman
Assistant Professor, Department of Prosthodontics, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Professor, Dental Research Center Dentistry Research Institute, Tehran University of Medical Sciences, Department of Orthodontics, Tehran University of Medical Sciences, Tehran, Iran.
J Dent (Tehran). 2014 Sep;11(5):523-30. Epub 2014 Sep 30.
Distal extension removable partial denture is a prosthesis with lack of distal dental support with a 13-fold difference in resiliency between the mucosa and the periodontal ligament, resulting in leverage during compression forces. It may be potentially destructive to the abutments and the surrounding tissues. The aim of this study was to assess the effect of implant location on stress distribution, in distal extension implant assisted removable partial dentures.
Three-dimensional models of a bilateral distal extension partially edentulous mandible containing anterior teeth and first premolar in both sides of the arch, a partial removable denture and an implant (4×10mm) were designed. With the aid of the finite element program ANSYS 8.0, the models were meshed and strictly vertical forces of 10 N were applied to each cusp tip. Displacement and von Mises Maps were plotted for visualization of results.
When an implant was placed in the second premolar region, the highest stress on implant, abutment tooth and cancellous bone was shown. The lowest stress was shown on implant and bone in the 1(st) molar area.
Implants located in the first molar area showed the least distribution of stresses in the analyzed models.
远中游离可摘局部义齿是一种缺乏远中牙支持的修复体,黏膜与牙周膜的弹性相差13倍,在压缩力作用下会产生杠杆作用。这可能对基牙和周围组织造成潜在破坏。本研究的目的是评估种植体位置对远中游离种植体辅助可摘局部义齿应力分布的影响。
设计双侧远中游离部分缺牙下颌骨的三维模型,牙弓两侧包含前牙和第一前磨牙,一个可摘局部义齿和一个种植体(4×10mm)。借助有限元程序ANSYS 8.0,对模型进行网格划分,并在每个牙尖施加10N的垂直力。绘制位移和冯·米塞斯图以直观显示结果。
当种植体置于第二前磨牙区域时,种植体、基牙和松质骨上的应力最高。在第一磨牙区域的种植体和骨上显示的应力最低。
在所分析的模型中,位于第一磨牙区域的种植体应力分布最少。