【作者】 朱啸；

【导师】 唐亮；

【作者基本信息】 暨南大学 ， 口腔临床医学， 2008， 硕士

【摘要】 研究目的建立下颌第二前磨牙和相同部位牙种植全冠修复体及其支持组织的三维有限元模型,采用三维有限元法比较分析天然牙与种植义齿位移的差异,为临床天然牙-种植体联合修复的应用提供理论参考依据。研究方法以人类正常下颌骨为建模的实体参照,应用CT扫描技术、AutoCAD及ANSYS的建模程序,建立了第二前磨牙、相同部位牙种植全冠修复体及其支持组织的三维有限元模型。在单个模拟的咀嚼周期内,对其分别进行垂直及斜向的动态加载,得到相应时间段的位移量和位移方向,并比较差别。结果1建立了两组具有良好几何和力学相似性的三维有限元模型。2动态加载下,天然牙与牙种植体的位移量有统计学差异,在0.15～0.26s、0.30～0.875s内二者差异位于颈部和根部,在0.26～0.30s内二者差异位于根部。3种植体人造冠与基台的位移量差距较大,二者间存在一定的相对活动度。4除冠部外,在斜向载荷下天然牙的最大位移量为36.759μm,牙种植体为26.377μm。在同一时间点内天然牙颈部的最大位移量最高可达牙种植体的2.98倍。5受牙周膜的影响,天然牙根和根尖点的位移量随着时间的增加变化显著,而牙种植体的变化缓慢。6天然牙与牙种植体的位移方向有所不同。结论1应用有限元建模方法,可以重建复杂生物组织的三维有限元模型,所得模型具有较好的几何和力学相似性。2牙种植体人造冠的位移量可达种植体基台的163.8倍,二者界面之间存在较大的相对位移。3除牙冠部外,在0.134～0.30s,天然牙各点的最大位移量均高于牙种植体,且斜向加载的影响最为明显。4在同一时间点上,天然牙与牙种植体位移量的差距较小。5天然牙随加载方向的改变而作相应的旋转运动,旋转中心在舌侧颈缘及颊侧牙根1/2处变化,而牙种植体的人造冠在作旋转运动时,种植体却保持稳定的位移方向。更多还原

【Abstract】 ObjectiveTwo three-dimensional finite element models of a human mandibular second premolar and an implant of full crown restoration under equal conditions and the supporting tissues have been established to compare the displacement differences between natural teeth and implants,so as to provide theoretical references to the tooth-implant-supported fixed denture.MethodsA normal human mandible was used as an anatomy foundation to establish a three-dimensional finite element model with CT scanning aided model building, AutoCAD software and ANSYS software.Finite element analysis was performed on the tooth model and the implant of full crown restoration and the supporting tissues model under vertical and oblique dynamic loads in a circle of mastication.The amount and directions of displacement of these 2 models were obtained and compared.Results1 Two three-dimensional finite element models were constructed successfully with great resemblance in geometry and mechanics.2 When dynamic loads were applied,there was statistical difference in the displacement of the natural tooth and of the implant.In 0.15～0.26s and 0.30～0.875s, the difference between the natural tooth and the implant was found in the cervical and the root.In 0.26～0.30s,the difference was found in the root.3 The artificial crown of the implant and implant abutment had large difference in the amount of displacement,where relative movement appeared. 4 Except the dental crown,under the oblique loads,the maximum amount of displacement of the natural tooth was 36.759μm,and the maximum amount of displacement of the implant was 26.377μm.The maximum amount of displacement at the cervical of the natural tooth could be 2.98 times more than that of the implant at the same point of time.5 By the influence of the periodontal membrane,there was a significant variance in the amount of displacement at the root and the root apical of natural tooth with time. But the variance of implant changed slowly.6 There was difference between the natural tooth and the implant in the directions of displacement.Conclusions1 A complicated biological tissue model with good geometry and mechanics resemblance can be established by applying the finite element method.2 The maximum amount of displacement at the artificial crown of tooth implant can be 163.8 times more than the implant abutment.There is large relative movement between the implant abutment and the artificial crown of the implant.3 Except the crown,in 0.134～0.30s,each point of natural tooth has larger amount of displacement than the implant,especially under the oblique loads.4 At the same point of time,the difference between the amount of displacement of natural tooth and implant is small.5 The natural tooth revolves following by the different loading directions.The rotation center of the natural tooth locates at lingual cervical or 1/2 buccal root of tooth.When the artificial crown of the implant revolves,the implant right along maintains a stable direction of displacement.更多还原