Load Transfer of abutment tooth with post and core for Various mandibular distal extension cases with diminished periodontal support

本研究采用准三维光弹性方法、高速光弹性实验方法和有限元方法，研究了RPI系统、Konus Krone系统和支撑臂系统三种固位体固定方式在双侧和单侧远中伸展病例中牙髓和非牙髓基牙的应力重分布情况。牙周受损的牙齿结构、牙周膜和牙槽骨采用单独的模拟材料。铸造了三个固位体来固定牙齿。分别制作RPI系统、Konus Krone系统和支撑臂系统三种固位体设计的单侧和双侧义齿。将模拟的垂直和侧向咬合载荷施加到义齿上，并在Suppo…中产生应力对更多的rt结构进行了光弹性监测。结果，以下情况变得清晰起来。1)三种系统在基牙及周围组织中的应力重分布模式不同。2)RPI系统在5个方向的载荷分布最为均匀，而Konus Crone系统在垂直、后向载荷上表现出良好的应力再分布，而颊向载荷和支撑臂配置在前向载荷和舌向载荷下表现出良好的应力再分布。3)牙周支撑力最小的基牙：35%的水平缺损处应力集中程度最高。增加夹板牙齿的数量并没有提供最大应力水平成比例的下降。4)非髓核桩核基牙的应力集中程度较高。5)不同大小的Spreddar根管充填侧向加压根管所产生的应力差异。6)准三维光弹性方法与有限元结果一致。较少

The purpose of this study was to investigate the stress redistribution in the pulp and non-pulp abutments in bilateral and unilateral distal extension cases with reduced periodontal support of three retainers device configurations based on the RPI system, Konus Krone system, and Bracing arm system using Quasi-three-dimensional Photoelastic method, High-speed Photoelastic Experimental Method and Finite Element Method.Three composite photoelastic models were made of a mandible unilaterally and bilateral edentulous distal to the second premolars. Individual simulant materials were used for tooth structure, periodontal ligament, and alveolar bone of periodontally compromised. Three retainers were cast for the teeth. Unilateral and bilateral partial dentures with three retainer designs, RPI system, Konus Krone system and Bracing arm system were made for the three models. Simulated vertical and lateral occlusal loads were applied to the dentures, and the stresses which developed in the suppo … More rting structures were monitored photoelastically.As a results, it's became clear the following. 1)The stress redistribution patterns in the abutments and surrounding tissues differed between the three systems. 2)The RPI system configurations showed the most uniform redistributions across loads directed in all five directions, while Konus Crone systems showed favorable stress redistribution for vertically, posteriorly, and buccally directed loads and Bracing arms configurations showed favorable stress redistribution for anteriorly and lingually directed loads. 3)the highest stress concentrations were seen in the abutment with the least periodontal support : the 35% horizontal defect. Increasing the number of splinted teeth did not provide a proportional decrease in maximum stress levels. 4)higher stress concentrations were seen in the abutment of non-pulp with post metal core. 5)The differents stress developed by lateral condensation root canal filling using various sizes spreddar. 6)it's became same results both Quasi-three-dimensional Photoelastic Method and Finite Element Method. Less