附着体义齿修复单侧游离端缺失的应力中断式设计和生物力学分析

发布时间：2018-05-09 07:35

本文选题：冠外弹性附着体 + 分裂基托　；参考：《第三军医大学》2016年硕士论文

【摘要】：游离端缺失是临床上常见的牙列缺损类型,由于缺损位于牙列末端,缺少远端基牙,且受上颌窦、下颌神经管等解剖结构限制,可摘局部义齿(RPD)仍然是目前临床最常选用的一种修复方式。常规RPD修复游离端缺失后,远中鞍基功能状态中常常下沉,从而对基牙产生较大的非轴向扭力,这是造成RPD基牙和牙周组织损伤并最终导致修复失败的主要原因。研究表明,弹性附着体义齿具有应力缓冲作用,可以减小对支持组织的损伤。分裂基托则通过应力中断的的机制,将基牙受到的非轴向力转变为轴向力,利于支持组织的健康。为此,本研究结合冠外弹性附着体(ERA)和分裂基托设计了单侧游离端缺失的应力中断式修复方式,在此基础上,构建三维数字模型,通过三维有限元法(3D FEM)研究义齿在不同功能载荷下的应力分布情况,从生物力学的角度探讨其应力分布规律,探索应力中断式附着体义齿修复远中游离端缺失的可行性,为临床应用提供研究基础。方法:1、制取个别正常牙合志愿者的下颌模型,磨除46、47和48并平整牙槽嵴以模拟右侧下颌游离端缺失,设计并制作了应力中断式附着体义齿。2、选择同一志愿者进行下颌骨和牙列的数据采集,在逆向工程软件中建立三维实体模型和网格划分,构建分裂基托ERA附着体义齿和普通ERA附着体义齿的三维有限元模型。3、分别对两组附着体的三维有限元模型施加轴向载荷,比较基牙、牙周组织、游离端牙槽嵴最大von Mises应力值及其应力分布。4、分别对两组修复体的三维有限元模型施加非轴向(颊舌向、近远中向)载荷,比较基牙、牙周组织、游离端牙槽嵴的最大von Mises应力值及其应力分布。结果:1、完成附着体义齿修复下颌单侧游离端缺失的应力中断式设计,并制作了应力中断式附着体义齿。2、建立了两组ERA附着体义齿修复单侧游离端缺失的三维有限元模型。普通组得到473376个节点和238800个单元,分裂基托组共得到447567个节点和233576个单元,并进行了有效的初步运算。3、普通组和分裂基托组在轴向载荷时应力分布规律一致,末端基牙应力主要分布在远中颈部,最大von Mises应力值分别为40.236MPa和12.056MPa,分裂基托组较普通组降低了233%;分裂基托组基牙牙周膜应力小于普通组;缺牙区牙槽嵴近中应力稍高,牙槽骨应力略高于普通组,分裂基托组总体分布更均匀,。4、颊舌向载荷时两组ERA附着体应力分布规律一致,末端基牙在远中颈部应力集中,普通组和分裂基托组最大von Mises应力值分别为53.568MPa和39.255MPa,分裂基托组明显较小;基牙牙周组织应力主要分布在颈部,缺牙区牙槽嵴应力分布在近中,分裂基托组应力均低于普通组。近远中向载荷时两组应力分布规律有所不同,普通组末端基牙远舌侧为应力集中区,最大von Mises应力值为21.323MPa,分裂基托组基牙应力集中区位于近舌侧颈部,最大von Mises应力值为17.926MPa;基牙牙周膜应力主要分布于远中,分裂基托组应力分布均匀程度高于普通组;基牙颈部牙槽骨和缺牙区近中牙槽骨为应力主要分布区,分裂基托组应力低于普通组。5、分裂基托ERA附着体基牙和牙周组织非轴向载荷时的应力明显高于轴向载荷时,其中颊舌向时最大,垂直向最小。结论:1、根据单侧游离端缺失应力中断式附着体修复的设计,成功建立了其三维有限元模型。较一般建模法提高了模型的几何相似性和力学相似性,通过初步验证分析保证了计算的准确性。2、与普通ERA附着体比较,轴向载荷时分裂基托ERA附着体充分达到应力中断的效应,基牙在得到保护的同时可以承担较多的牙合力;更多的牙合力转移至缺牙区牙槽嵴,减轻基牙了的负担;整体上促进了基牙和缺牙区牙槽嵴平衡和分散牙合力的作用。3、与普通ERA附着体比较,分裂基托ERA附着体在非轴向载荷时通过应力中断机制,达到对基牙和牙周组织一定程度的保护作用,支持组织支撑作用的加强提高了义齿的稳定性,其中颊舌向力对支持组织的影响最大。4、分裂基托ERA附着体义齿通过应力中断机制比普通ERA附着体降低了基牙所受扭侧向扭力,利于维护支持组织的健康,为游离端缺失的临床修复提供了较好的修复策略。
[Abstract]:Free end deletion is a common clinical dentition defect type. Due to the defect located at the end of the dentition, the lack of distal base teeth, and the anatomical structure of the maxillary sinus and the mandibular nerve canal, the removable partial denture (RPD) is still the most commonly used repair method at present. After the normal RPD repair, the free end of the free end is in the function state of the far middle saddle base. This is the main cause of the failure of the RPD base teeth and the periodontal tissue damage. The study shows that the elastic attachment denture has a stress buffer and can reduce the damage to the supporting tissue. The change of the non axial force to the axial force is beneficial to support the health of the tissue. Therefore, this study combines the ERA and the split base to the design of the stress interruption repair mode of the unilateral free end loss. On this basis, a three-dimensional digital model is constructed and the three dimensional finite element method (3D FEM) is used to study the denture under different functional loads. The stress distribution of the stress distribution is discussed from the biomechanical point of view, and the feasibility of the repair of the distal and distal end deletion of the stress interruption attachment denture is explored. Methods: 1, the mandibular model of the volunteers in a few normal occlusion is made, and the 46,47 and the 48 and flat alveolar ridge are removed to simulate the right mandible. Free end deletion, the stress interruption attachment denture.2 was designed and made, and the data collection of the mandible and tooth column was selected by the same volunteers. Three dimensional solid model and grid division were set up in the reverse engineering software, and the three-dimensional finite element model of the ERA attachment denture and the common ERA attachment denture was constructed, which were two groups respectively. The three-dimensional finite element model of the attachment applied the axial load to compare the maximum von Mises stress value of the base teeth, the periodontal tissue, the free end alveolar ridge and the stress distribution.4, and applied the non axial (cheek tongue, near far middle) load to the three-dimensional finite element model of the two groups, compared with the largest von Mises of the base teeth, the periodontium and the free end of the alveolar ridge. Stress distribution and stress distribution. Results: 1, the stress interruption design of the attachment denture to repair the unilateral free end of the mandible was completed, and the stress interruption attachment denture.2 was made, and a three-dimensional finite element model of two groups of ERA attachment dentures was established for the unilateral free end deletion. 473376 nodes and 238800 units were obtained in the ordinary group. A total of 447567 nodes and 233576 units were obtained in the crack base group, and the effective initial operation.3 was carried out. The stress distribution of the common group and the split base group was the same in the axial load. The stress of the terminal base tooth was mainly distributed in the far middle and the neck, the maximum von Mises stress was 40.236MPa and 12.056MPa respectively, and the split base group decreased by 2 compared with the ordinary group. 33%, the stress of the periodontal membrane of the split base group was less than that of the common group; the stress in the alveolar ridge was slightly higher, the stress of the alveolar bone was slightly higher than that of the common group, and the overall distribution of the split base group was more uniform. The stress distribution of the two groups of attachments in the.4 and the buccal tongue was the same, the end base teeth were concentrated in the far middle and neck regions, and the most common group and the split base group were the most important. The stress values of the large von Mises were 53.568MPa and 39.255MPa, and the split base group was significantly smaller. The stress in the periodontal tissue was mainly distributed in the neck, and the stress distribution in the alveolar ridge was in the near middle. The stress of the split base group was lower than that of the common group. The stress distribution in the two groups was different in the near far middle direction, and the distal lingual side of the end of the common group was the distal lingual side. In the stress concentration area, the maximum von Mises stress value is 21.323MPa. The stress concentration area of the base teeth in the division base group is located near the lingual side neck and the maximum von Mises stress value is 17.926MPa. The stress of the periodontal ligament is mainly distributed in the far middle, the distribution of the stress distribution in the division base group is higher than that of the common group; the alveolar bone in the base tooth and the proximal alveolar bone in the tooth area of the teeth of the abutment neck are of the middle alveolar bone. In the main stress distribution area, the stress of the split base group is lower than that of the common group.5. The stress of the base teeth of the split base ERA attachments and the non axial load of the periodontal tissue is obviously higher than that of the axial load, of which the buccal tongue is the largest and the smallest. Conclusion: 1, the third is the design of the single side free end deletion stress interruption attachment. The geometric similarity and mechanical similarity of the model are improved compared with the general modeling method. The accuracy of the calculation is guaranteed by preliminary verification and analysis.2. Compared with the common ERA attachment, the effect of the splitting of the base ERA attachments is fully achieved when the axial load is loaded, and the base teeth can bear more teeth while they are protected. Combined force, more joint force transfer to the alveolar ridge in the odontist area, lighten the burdens of the base teeth; promote the role of the alveolar ridge balance and the dispersion of the dental joint force in the basic teeth and the odontist area as a whole.3, and compare with the common ERA attachment, the split base ERA attachment through the stress interruption mechanism in the non axial load, to a certain degree to the base teeth and periodontal tissue. The stability of the denture is enhanced by the strengthening of the supporting role of the tissue, in which the influence of the buccal tongue force on the support tissue is most.4. The split base ERA attachment denture reduces the torsion lateral torsion of the base teeth through the stress interruption mechanism than the ordinary ERA attachment, and is beneficial to the maintenance of the health of the supporting tissue and the absence of the free end. Bed repair provides a better repair strategy.

【学位授予单位】：第三军医大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：R783.6

【参考文献】