种植体植入部位对全下颌种植覆盖义齿应力分布的影响

目的:对不同种植体植入部位的全下颌种植覆盖义齿及支持组织进行力学分析,为优化种植覆盖义齿设计提供依据。方法:应用三维有限元法,对分别采用颏孔前和尖牙、磨牙区植入种植体的全下颌种植覆盖义齿进行应力分析,对比义齿本身和支持组织应力分布的差异。结果:①颏孔前植入的覆盖义齿对斜向载荷的抵抗性差,种植体-骨界面应力峰值为垂直载荷的2.4～9.2倍;垂直及斜向载荷,种植体和基托均有较高的应力集中。②尖牙、磨牙区植入的覆盖义齿,垂直及斜向载荷时均表现了较佳的力学特性,支持组织应力峰值位于骨维持的生理范围内。结论:磨牙区种植体的植入可增强覆盖义齿对侧向力的抵抗能力,降低种植体-骨界面应力峰值,减少机械性并发症的发生。而单纯颏孔前植入设计时,应考虑采用缓冲设计,提高覆盖义齿的远期成功率。     

不同附着体下颌种植覆盖义齿咬合运动与应力分布的有限元研究

目的：采用有限元分析法,研究不同附着体类型对种植覆盖义齿咬合运动方式、载荷分配及牙槽骨内应力分布的影响。方法：采集下颌骨及其所佩戴义齿的CT数据,利用逆向工程技术构建包含下颌骨、附着体（杆卡附着体B;ERA附着体E;球帽附着体R;磁性附着体M）和义齿的完整下颌2植体种植覆盖义齿三维有限元模型,通过对上述不同部件接触关系的定义,模拟正中咬合力作用下,种植覆盖义齿运动方式、载荷分配及颌骨内应力分布情况。结果：正中咬合时,ERA组和球帽组义齿整体均匀沉降,植体所受载荷较小;磁性组和杆卡组垂直向无缓冲,义齿前端无沉降,后端旋转下沉,植体所受载荷增大。植体周围应力分布：杆卡组最高,磁性组其次,ERA组较低,球帽组最低;后方牙槽嵴应力分布：杆卡组最高,球帽组其次,ERA和磁性组最低。结论：不同附着体类型对义齿的运动方式、载荷分配及应力分布有显著影响;附着体缓冲间隙可以延缓植体所受垂直向载荷,降低植体周围颌骨吸收的风险。     

种植全口覆盖义齿应力分布的三维有限元分析

目前种植技术在无牙颌患者中应用广泛,但随之亦发现种植固定义齿的一些不足,所以种植覆盖义齿应运而生,并以其特有的优势得到了越来越多的关注,那么种植体支持的覆盖义齿在固位方式、种植体的数量和植入部位等方面该如何选择和把握呢?本文利用三维有限元的分析方法,研究受力状态下的无牙颌种植覆盖义齿应力分布状况,并对应力分布的影响因素进行探讨,拟为种植覆盖义齿应力分布均匀,优化种植覆盖义齿的临床修复设计提供理论依据,从而提高种植覆盖义齿的远期成功率.     

窄径植体下颌种植覆盖义齿的优化设计

目的：利用有限元法,分析不同种植体数目及附着体类型,对下颌窄径种植覆盖义齿颌骨内应力分布的影响。方法：采集患者下颌骨及其所佩戴覆盖义齿的CT数据,利用逆向工程技术构建包含下颌皮质骨、松质骨、附着体（杆卡附着体B;球帽附着体R;磁性附着体M）及覆盖义齿的完整下颌窄径种植覆盖义齿的三维有限元模型,通过对上述不同部件接触关系的定义,模拟右侧后牙垂直咬合作用下,不同植体数目及附着体类型对下颌窄径种植覆盖义齿颌骨内应力分布的影响。结果：偶数枚植体设计,植体周围应力峰值明显低于奇数枚植体设计;杆卡附着体植体周围应力峰值较低,球帽附着体其次,磁性附着体最高;杆卡附着体随着植体数目的增多,植体周围应力峰值降低;磁性附着体随着植体数目的增多,植体周围应力峰值反而增高。结论：植体数目和附着体类型对于颌骨内的应力分布均有显著影响;建议临床优先选用偶数枚植体的杆卡附着体设计;其次建议使用两植体球帽附着体设计。     

下颌平面角影响种植体应力分布的有限元分析

目的通过在不同下颌平面角角度下对下颌第一磨牙种植体的力学特性进行有限元分析,得出下颌平面角角度对种植体受力的影响规律,为临床种植提供理论参考。方法采集3种不同下颌平面角（低角、均角、高角）CT数据,建立种植复合体有限元模型,设计正交实验方案,记录数据,分析处理,得出有限元分析结果。结果最优参数组合为：低角,4.8 mm,Ⅱ型骨。各个因素的主次关系依次为种植体直径、下颌平面角角度、骨密度。结论下颌平面角角度对种植体的稳固有一定的影响,在同样咬合力的情况下,高角种植体所受应力最大,其次是均角,低角最小。     

套筒冠固位的下颌种植覆盖义齿的应力分析

目的：分析比较增加种植体数目与采用缓冲式支持对下颌种植覆盖义齿的稳定性及支持组织的应力分布的影响。方法：应用三维有限元法。结果：采用缓冲式支持可更好的降低支持组织的应力峰值，但对种植体的保护及义齿的稳定作用不及多个种植体式支持。结论：采用两个种植体的缓冲支持形式即可使下颌种植覆盖义齿的种植体周围支持组织获得比较理想的应力分布效果，有利于种植体周围组织的健康，提高种植义齿的远期成功率。     

不同种植位点下附着体类型对短种植体覆盖义齿的应力影响

目的:研究不同种植位点下附着体类型对于短种植体辅助固位式覆盖义齿修复KennedyⅠ类缺失时的应力分布效果.方法:建立短种植体辅助固位式覆盖义齿修复下颌双侧前磨牙及磨牙全部缺失的三维有限元模型,根据种植位点(位点A:第二前磨牙区、位点B:第一磨牙区、位点C:第二磨牙区)及附着体类型构建9个实验组:A-Brevis、A-...     

种植覆盖义齿修复牙槽骨严重萎缩的无牙下颌

目的：本文报告用Replace种植体或MIC种植体支持、用夹子和杆固定种植覆盖义齿修复牙槽嵴严重萎缩的无牙下颌患者的治疗程序，重点介绍了修复体制作要点，评价了种植覆盖义齿的修复效果。方法：在每个无牙下颌前牙区植入2～3枚Replace种植体、或MIC种植体。连接基台，制作做固位用的杆结构。覆盖义齿通过放置在组织面的塑料或合金夹子固位到杆结构上.用该方法修复严重萎缩的无牙下颌19例，其中，17位患者按期进行了复查，从种植效果和修复效果两个方面对复查患者的治疗结果进行了评价。结果：17位按期复诊者的43枚种植体及其支持的杆结构稳定。修复后咀嚼功能恢复良好，面容和语音功能有显著改观，患者对种植修复治疗结果都感到满意。结论：用种植组合体固住的下颌半口覆盖义齿修复严重萎缩的无牙下颌，能够有效地恢复咀嚼功能，改善面容，提高语音的清晰度，达到预期的效果。     

软衬材料固位的全下颌种植覆盖义齿三维有限元应力分析

目的 探讨弹性缓冲装置对种植覆盖义齿应力分布的影响，为优化种植覆盖义齿设计提供依据。方法 应用三维有限元法，对采用弹性软衬材料和非弹性材料固位的全下颌种植覆盖义齿进行应力分析，对比义齿本身和支持组织应力分布的差异。结果 ①无弹性材料缓冲的覆盖义齿对斜向载荷的抵抗性差，种植体颈部—皮质骨界面应力峰值为垂直载荷的2．4～9．2倍。垂直及斜向载荷，种植体及基托均有较高的应力集中。②弹性软衬材料固位的覆盖义齿，垂直及斜向载荷时，种植体—骨界面及义齿本身应力分布较均匀，避免了较大的应力集中。结论 弹性软衬材料应用于全下颌种植覆盖义齿时，表现了良好的应力缓冲作用，降低了种植体—骨界面应力峰值，减少机械性并发症的发生，有利于提高种植覆盖义齿的远期成功率。     

单个下颌磨牙缺失种植修复体尺寸对骨界面应力分布的影响

目的：分析单个下颌磨牙缺失采用种植修复时，种植体尺寸对骨界面的应力分布的影响。方法：采用三维有限元法，模拟单个种植体及双种植体修复单个缺失下颌第一磨牙的情况，在保证其它因素不变的条件下，分析种植体尺寸(包括种植体长度和直径)对种植体一骨界面应力分布的影响。结果：不论单种植体修复或双种植体修复单个缺失磨牙时，种植体直径变化对种植体一骨界面应力影响较大，斜向载荷时更为明显；而种植体长度对骨界面应力影响较小。结论：建议临床尽量采用直径较大的种植体修复单个缺失下颌磨牙。     

Indigenous ball and socket implant supported mandibular overdenture: A case report

Edentulism is a major health concern of old age. Indigenous implant based over dentures offer a cost effective option for severely resorbed dental ridges. Here, we report rehabilitation of a resorbed mandibular arch with indigenous implant supported overdenture and maxillary arch with a conventional denture. Two ball and socket implants were placed bilaterally in the parasymphyseal area. Existing denture was relined to accommodate the ‘ball head’ of the implant in the interim period. Four months later, when patient was taken up for denture fabrication, the ‘socket part’ of the ball and socket implant was incorporated into the new denture base. The socket provided a fitting surface for the implant. Implant supported overdenture significantly increased the retention, support and stability of the lower denture. Further, it worked well with the upper conventional denture. The simple design and efficacy of indigenous implant based overdenture holds promising aspects in the treatment of edentulism.     

Resilient liner vs. clip attachment effect on peri‐implant tissues of bar‐implant‐retained mandibular overdenture: a 1‐year clinical and radiographical study

Purpose: The aim of this study was to compare between the effects of resilient liner and clip attachments of bar‐implant‐retained mandibular overdenture on peri‐implant tissues. Materials and methods: In a randomized‐controlled clinical trial, 30 edentulous male patients (mean age 62.5 years) were equally assigned to two groups. In each patient, two implants were inserted in the canine area of the mandible using a two‐stage surgical protocol. After 3 months, the implants were connected with resilient bars. Mandibular overdentures were retained to the bars with either clips (group I) or silicone‐resilient liners (group II). Peri‐implant tissues were evaluated clinically (with regard to plaque scores, gingival scores and probing depths) and radiographically (with regard to peri‐implant vertical and horizontal alveolar bone changes). Evaluations were performed at the time of overdenture insertion (T0), 6 months (T6) and 12 months (T12) after overdenture insertion. Results: After 12 months of using bar‐implant‐retained mandibular overdenture, the resilient liner attachment had significantly decreased peri‐implant plaque score, gingival score, probing depth, vertical and horizontal bone loss when compared with the clip attachment. Conclusion: Within the limitations of this study, and in terms of peri‐implant tissue health of bar‐implant‐retained mandibular overdenture, we recommend resilient liner rather than clip attachment. To cite this article:
Elsyad MA, EL Shoukouki AH. Resilient liner vs. clip attachment effect on peri‐implant tissues of bar‐implant‐retained mandibular overdenture: a 1‐year clinical and radiographical study.
Clin. Oral Impl. Res. 21 , 2010; 473–480
doi: 10.1111/j.1600‐0501.2009.01879.x     

Five years of aftercare of implant-retained mandibular overdentures and conventional dentures

The purpose of this multicentre randomized clinical trial was to analyse surgical and prosthetic aftercare and clinical implant performance of edentulous patients with implant‐retained mandibular overdentures and of patients with conventional dentures, either or not after pre‐prosthetic vestibuloplasty and deepening of the floor of the mouth. The evaluation period was 5 years. The implant systems evaluated were the IMZ implant system, the Brånemark implant system and the Transmandibular Implant system. The centre in Groningen had five groups (n=149) and the centre in Nijmegen had three groups (n=86). The evaluation comprised of surgical and prosthetic aftercare, together with clinical implant performance (CIP). The highest implant loss (29%) is found in the Transmandibular Implant group. All groups had prosthetic revisions and complications according to the CIP‐scale. The majority of the patients in the endosseous implant groups were subject to minor complications. The CIP‐score of the Transmandibular Implant group is significantly higher than the scores of the other groups, because of the high number of lost posts. In 26˙1% of the patients in this group score 4 is given, which means failure of the implant system. From this study it can be concluded that the endosseous implant systems used in this study have less surgical aftercare and a better clinical implant performance than the Transmandibular Implant system and are therefore the systems of choice for the edentulous mandible.