种植体支持的覆盖可摘义齿修复下颌Kennedy Ⅰ类缺损及其支持组织的应力分析

发布时间：2019-06-22 08:47

【摘要】：目的·应用三维光弹性应力分析法,比较不同直径种植体支持的覆盖RPI型可摘局部义齿与常规RPI型可摘局部义齿在垂直载荷下基牙、缺牙区牙槽骨及种植体周围的应力分布情况。方法·选取标准下颌模型,制备形成下颌KennedyⅠ类牙列缺损。在双侧第一磨牙区分别植入不同直径(4.1 mm和3.3 mm)的Straumann系统软组织水平种植体各2枚。将种植钉及环氧树脂牙倒置于下颌硅橡胶阴模中,制作环氧树脂光弹模型,并将RN愈合基台旋入种植体内。将含有模拟2 mm厚的牙槽黏膜及下颌传统RPI型可摘局部义齿置于环氧树脂模型上(分别为含种植体和不含种植体),正中咬合状态下对模型垂直加载1 kg力。应力冻结后,切取相应牙位的模型切片,观测应力条纹图样,以单位厚度的条纹级数值计算应力大小。结果·常规RPI型可摘局部义齿远中基牙的最大应力值主要集中在根尖区,其缺牙区牙槽骨中最大应力集中在第一磨牙区,且集中在牙槽骨舌侧。种植体支持的覆盖RPI型可摘局部义齿远中基牙最大受力值小于常规RPI型可摘局部义齿远中基牙的最大受力,同时其缺牙区牙槽骨(不含种植体部分)最大受力与基牙及其支持组织的受力接近,且最大受力值小于常规RPI型。种植体周围应力最大,且种植体尖周应力值大于颈部应力值。同时,随着种植体直径变小,其种植体周围最大应力值相对变大。结论·与常规RPI型可摘局部义齿比较,种植体支持的覆盖RPI型可摘局部义齿的稳定性增加,支持组织的受力更趋均衡,对基牙及其缺牙区支持组织的健康有利。
[Abstract]:Objective to compare the stress distribution between RPI removable partial denture supported by different diameters and conventional RPI removable partial denture under vertical load, alveolar bone and around implantation by three dimensional photoelastic stress analysis. Methods the standard mandibular model was selected to make mandibular Kennedy class I dentition defects. Two Straumann system soft tissue horizontal implants with different diameters (4.1 mm and 3.3 mm) were implanted in the bilateral first molar area. The photoelastic model of epoxy resin was made by placing the nail and epoxy resin teeth in the negative mold of mandibular silicone rubber, and the RN healing platform was rotated into the implantation body. The traditional RPI removable partial dentures with simulated 2 mm thickness were placed on epoxy resin model (with and without implants, respectively). The model was loaded vertically with 1 kg force in the middle occlusal state. After the stress is frozen, the model slices of the corresponding tooth position are cut, the stress stripes are observed, and the stress magnitude is calculated by the stripe level per unit thickness. Results the maximum stress of abutment teeth in the distal part of conventional RPI removable partial denture was mainly concentrated in the apical area, and the maximum stress in the alveolar bone in the missing area was concentrated in the first molar area, and concentrated in the lingual side of the alveolar bone. The maximum stress of the far middle abutment of the RPI removable partial denture supported by the Implant was lower than that of the far and middle denture of the conventional RPI removable partial denture, and the maximum stress of the alveolar bone (excluding the part of the implant) in the missing tooth area was close to that of the denture and its supporting tissue, and the maximum stress value was lower than that of the conventional RPI type. The stress around the implantation was the largest, and the stress value around the tip of the implantation was larger than that around the neck. At the same time, with the decrease of the diameter of the implantation, the maximum stress value around the implantation became relatively larger. Conclusion compared with conventional RPI removable partial denture, the stability of RPI removable partial denture supported by implantation is increased, and the force of supporting tissue is more balanced, which is beneficial to the health of denture and its missing teeth.
【作者单位】：北京大学口腔医院第三门诊部综合一科;上海市普陀区中心医院口腔科;上海交通大学医学院附属第九人民医院口腔特需科;
【分类号】：R783.6

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