球帽附着体下颌种植覆盖义齿牙槽骨的三维光弹应力分析

目的：研究球帽附着体下颌种植覆盖义齿在各种咬合状态时下颌牙槽骨的应力分布。方法：制作球帽附着体下颌种植覆盖义齿光弹模型,分别在正中位、前伸位、侧向位咬合时进行三维光弹应力分析。结果：三种位下,种植体颈部和尖周应力值较大,并且尖周大于颈部;正中余留牙槽嵴内最大应力出现在第二磨牙颊侧;侧向余留牙槽嵴内最大应力值出现在双侧第二磨牙区,工作侧最大应力出现在牙槽嵴唇颊侧,平衡侧最大应力出现在牙槽嵴舌侧;前伸余留牙槽嵴内最大应力出现在第二磨牙区颊侧。结论：球帽附着体下颌种植覆盖义齿在各位咬合状态时种植体颈部和尖周应力集中,尖周应力值最大;余留牙槽嵴内后牙区域的应力值较大。     

磁性附着体下颌种植覆盖义齿牙槽骨的三维光弹应力分析

目的：研究磁性附着体下颌种植覆盖义齿在各种咬合状态时下颌牙槽骨的应力分布。方法：选取标准无牙颌模型,在双侧尖牙区植入种植体,连接磁性附着体,翻制下颌环氧树脂模型,制作生物功能性全口义齿,分别在正中、前伸、侧向咬合时加载应力,冻结切片,观测各牙位应力条纹。结果：磁性附着体下颌种植覆盖义齿在正中、侧向、前伸咬合应力加载时种植体周围牙槽骨应力值最大,余留牙槽嵴后牙区所受应力大于前牙区。正中、前伸磨牙区最大应力值出现于颊侧,切牙区最大应力值出现于舌侧。侧向工作侧最大应力值出现于唇颊侧,平衡侧最大应力值出现于舌侧。结论：磁性附着体种植覆盖义齿各向咬合时,应力既分布到种植体,也分布到剩余牙槽嵴,可以明显降低种植体周围骨组织的受力,有利于种植体的健康。     

杆卡附着体下颌种植覆盖义齿牙槽骨的三维光弹应力分析

目的：研究杆卡附着体下颌种植覆盖义齿在各种咬合状态时下颌牙槽骨的应力分布。方法：制作杆卡附着体下颌种植覆盖义齿光弹模型,采用三维冷冻光弹法分析正中、前伸、侧向咬合状态下种植体周围与余留牙槽嵴的应力。结果：三种咬合状态下,种植体颈部和尖周牙槽骨应力值较大,尖周应力值大于颈部应力值;余留牙槽嵴最大应力值出现在磨牙区。侧向牙合工作侧各牙位切片的最大应力值出现于唇颊侧,平衡侧各牙位切片的最大应力值出现于舌侧;前伸牙合侧切牙区唇侧应力最大,中线区及后牙区应力最大值出现于舌侧。结论：杆卡式种植覆盖义齿在正中、前伸、侧向咬合状态下,种植体周围骨组织应力值较大,不利于种植体的健康,因此应用杆卡式附着体时,可考虑增加种植体,扩大基托面积,依据平衡牙合排牙以分散牙合力。     

球帽式与套筒冠式下颌种植覆盖义齿的三维有限元分析

目的:应用三维有限元分析,比较球帽式和套筒冠式附着体对下颌种植覆盖义齿的应力分布的影响。方法:本实验应用三维有限元法分析,模拟下颌覆盖义齿在正中咬合状态下的受力情形。结果:两种模型中,骨组织界面应力主要都集中在种植体颈部周围的皮质骨中。球帽式附着体模型中牙槽嵴表面上的最大压应力峰值为-1.601Mpa,而套筒冠式附着体模型的压应力峰值为-0.296Mpa。套筒冠式附着体模型的中央种植体、侧方种植体上的应力峰值均小于球帽式附着体的种植体。结论:套筒冠式覆盖义齿较球帽式可降低种植体及剩余牙槽骨表面的应力,更有助于保存牙槽骨组织和种植体。     

三种缓冲机制的根面附着体式覆盖义齿的电测应力分析研究

目的 分析不同加载情况下,太极扣、球帽、磁性根面附着体支持的覆盖义齿基牙周围牙槽骨及缺牙区牙槽嵴的应力差异,为临床根面附着体的选择提供参考.方法 采用电阻应变测量法,体外模拟覆盖义齿受力情况,测量基牙牙颈部牙槽骨、下颌牙弓前部中央及第一磨牙相对应缺牙区牙槽嵴处的应力,并比较分析三种附着体式覆盖义齿在不同加载情况下应力差异.结果 不同缓冲机制附着体式覆盖义齿在相同加载情况下,义齿会出现一定程度的滑动(磁性附着体式覆盖义齿)或旋转(三种附着体义齿),基牙牙颈部不同部位牙槽骨、牙弓前部及游离端缺牙区牙槽嵴应力分布明显不同.结论 太极扣式覆盖义齿适应条件相对最广泛,其次为磁性附着体式覆盖义齿.     

种植覆盖义齿临床应用新进展

一、种植覆盖义齿的分类及应用1、种植体支持式,黏膜为主支持式,混合支持式。2、机械式附着体和磁性附着体。3、常用附着体结构:1.杆卡附着体;2.球状附着体;3.磁性附着体三、种植体周围的应力分布GozdeCelik等:球帽与杆卡混合设计的下颌覆盖义齿传导最小的应力到种植体上。刘政:球帽附着体覆盖义齿的剩余牙槽嵴表面应力大于杆式附着体义齿。Lucas Fernando等:与O’RING附着体相比,杆     

两种附着体种植覆盖义齿的临床效果比较

目的 评价球帽附着体和Locator 附着体应用于无牙颌患者种植覆盖义齿的临床效果.方法 选择无牙颌行种植覆盖义齿修复患者67例,共植入150颗种植体,附着体类型为球帽或Locator.对患者定期复查,检查种植体的牙周袋探诊深度(PPD),菌斑指数(PLI),牙龈指数(GI)和龈沟出血指数(BI),测量边缘骨吸收值(MBL).患者分为球帽组、球帽改Locator组和Locator组,对PPD值、MBL值和PLI、GI、BI分别进行3组间比较.使用Digimizer图像分析软件进行影像学测量,采用SPSS17.0软件进行统计分析.结果 150颗种植体修复前成功率为95.88%,累计存留率为92.97%.PPD值平均为(2.16 ± 1.02)mm,球帽组与改做组间无显著差异,Locator组的PPD值明显低于另2组.PLI、GI和BI的组间差异均无统计学意义.MBL值平均为(0.92 ± 0.61)mm,改做组的MBL值明显高于另2组,而Locator组的MBL值最低.结论 Locator式种植覆盖义齿比球帽式种植覆盖义齿的临床效果具有一定优势.     

下颌球帽附着体覆盖义齿应力研究

目的 分析不同球帽附着体下颌覆盖义齿在不同加载力作用下基托及支持组织所受的应力.方法 采用电阻应变测量法测量下颌球帽附着体覆盖义齿的应力,比较使用不同类型球帽附着体时,下颌覆盖义齿的应力变化.结果 使用金属球帽附着体比使用塑料球帽附着体牙根表面、义齿基托舌侧正中的应变值小,但后牙区 牙槽嵴顶粘膜表面应变值较大.义齿基托...     

球帽和Locator附着体种植覆盖义齿的临床疗效评价

目的:评价球帽附着体和Locator附着体应用于种植覆盖义齿的临床效果.方法:纳入无牙颌患者67例,共植入150颗Straumann或Bego种植体,完成球帽式或Locator式种植覆盖义齿修复.定期随访复查,包括修复后生物并发症和机械并发症情况和患者满意度调查.采用SPSS 17.0软件统计分析.结果:完成随访58例,球帽组35例,Locator组26例,球帽改Locator组7例.生物并发症比较显示,球帽组的牙龈增生发生率明显高于Locator组(P＜0.05);球帽组和Locator组的机械并发症发生率无显著差异(P＞0.05),但Locator组各类机械并发症的发生次数少于球帽组,球帽组平均修理频次为1.9次,Locator组为0.9次;Locator组患者对咀嚼和固位的满意度高于球帽组,不同性别的患者满意度无差异,满意度与患者的年龄和随访时间无相关性.结论:Locator式种植覆盖义齿相比球帽式种植覆盖义齿,临床效果具有一定优势.     

球帽附着体种植覆盖义齿在萎缩下颌无牙颌的应用

目的 探讨球帽附着体种植覆盖义齿在牙槽骨萎缩的下颌无牙颌病例中的应用。方法 用Endo—pore Dental Implant System种植体，球形基台和弹性橡皮帽，为15例牙槽嵴萎缩下颌无牙颌病人作球帽附着体种植覆盖义齿，观察义齿的固位力、稳定性和咀嚼功能，随访0．5—3年。结果 球帽附着体种植覆盖义齿能显著提高下颌全口义齿的固位力和稳定性，改善咀嚼功能，病人满意。结论 球帽附着体种植覆盖义齿修复能显著改善牙槽嵴萎缩的下颌全口义齿的功能。     

Locator附着体和球帽附着体在种植覆盖义齿中的临床修复效果比较

目的探讨球帽基台和locator基台在种植体覆盖义齿(IODs)修复中临床效果的比较。方法选择单颌牙根嵴严重萎缩全口无牙颌患者27例,共计54枚种植体,其中球基台附着体26枚,locator基台附着体28枚。上部修复完成后6个月复诊并每年随访,从种植体、牙周黏膜、附着体等方面进行复查,统计其总的并发症发生率并对患者的满意度进行评价。结果两种基台支持式覆盖义齿患者的满意度明显高于普通全口义齿(P<0.05)。2年后两种附着体种植覆盖义齿边缘骨吸收率(BML)没有差别(P>0.05)。locator基台支持的覆盖义齿并发症的发生率仅为14.28%,球帽种植覆盖义齿总的并发症发生率为38.46%。结论 locator基台和球帽基台支持式全口义齿均优于常规全口义齿,locator基台产生的并发症更少。     

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。     

Effects of overdenture attachment systems with different working principles on stress transmission: A three-dimensional finite element study

PURPOSEThe aim of the present study was to compare the stress distributions on the dental implants, abutments, and bone caused by different overdenture attachment types under functional chewing forces.MATERIALS AND METHODSThe 3D finite element models of the mandible, dental implants, attachment types, and prostheses were prepared. In accordance with a conventional dental implant supported overdenture design, the dental implants were positioned at the bone level in the canine teeth region bilaterally. A total of eight models using eight different attachment systems were used in this study. All the models were loaded to simulate chewing forces generated during the centric relationship (450 N), lateral movement (400 N), protrusive movement (400 N), and also in the presence of a food mass unilaterally (200 N). Stress outputs were obtained as the maximum principal stress and the equivalent von-Mises stress.RESULTSIn all attachment types, higher stress values were observed in the abutments, dental implants, and bone in the magnet attachments in different loading conditions. The highest stress values were observed among the magnet systems in the components of the Titanmagnetics model in all loading conditions (stresses were 15.4, 17.7, and 33.1 MPa on abutment, dental implant, and bone, respectively). The lowest stress value was observed in the models of Zest and O-Ring attachments.CONCLUSIONThe results of the present study implied that attachment types permitting rotation and tolerating various angles created lower stresses on the bone, dental implants, and abutments.     

A finite element study on stress distribution of two different attachment designs under implant supported overdenture

Objective

This study aimed to evaluate stress patterns generated within implant-supported mandibular overdentures retained by two different attachment types: ball and socket and locator attachments.

Materials and methods

Commercial CAD/CAM and finite element analysis software packages were utilized to construct two 3D finite element models for the two attachment types. Unilateral masticatory compressive loads of 50, 100, and 150 N were applied vertically to the overdentures, parallel to the longitudinal axes of the implants. Loads were directed toward the central fossa in the molar region of each overdenture, that linear static analysis was carried out to find the generated stresses and deformation on each part of the studied model.

Results

According to FEA results the ball attachment neck is highly stressed in comparison to the locator one. On the other hand mucosa and cortical bone received less stresses under ball and socket attachment.

Conclusions

Locator and ball and socket attachments induce equivalent stresses on bone surrounding implants. Locator attachment performance was superior to that of the ball and socket attachment in the implants, nylon caps, and overdenture. Locator attachments are highly recommended and can increase the interval between successive maintenance sessions.     

杆卡、球帽和locator附着体种植覆盖义齿的临床对比研究

目的：比较杆卡、球帽、locator附着体种植覆盖义齿修复1．3年后的临床效果。方法：对38名无牙颌患者进行覆盖义齿修复,其中杆卡、球帽、locator附着体种植覆盖义齿分别为11、18和9例。在义齿完成后0．5、1年及每年复查1次。对各组种植体周围粘膜状况和边缘骨吸收（MBL）进行评估,同时检验患者满意度。结果：杆卡、球帽、locator附着体最近一次随访的种植体边缘骨吸收为（1．3±1．0）ram、（1.2±0．8）mm、（1．4±1．0）mm,3种方式修复后MBL比较无统计学意义（P〉0．05）。与原有全口义齿比较,患者满意度均有明显提升（P〈0．05）。三种义齿间种植体周围粘膜状况、患者满意度亦无统计学差异。结论：杆卡、球帽、locator附着体种植覆盖义齿均能明显改善无牙颌患者的咀嚼功能。出于经济学考虑,我们建议选用2枚种植体支持的球帽或locator附着体覆盖义齿,临床上角度偏差较大的种植体可以优先考虑locator附着体覆盖义齿修复。     

A Three‐Dimensional Finite Element Analysis for Overdenture Attachments Supported by Teeth and/or Mini Dental Implants

Purpose: The aim of this study was to establish the optimum design and attachment combination to support an overdenture with minimal stress and flexing produced in the alveolar bone surrounding any natural teeth and/or mini dental implants. Materials and Methods: Twelve models were included in the study: the six main models (A, B, C, D, E, and F) were categorized according to the support designs of the overdenture prosthesis, and each model was further subdivided according to the attachment combinations into model 1: with Dalbo elliptic and/or O‐ring attachments only and model 2: with flexible acrylic attachments. Vertical loads (35 N) and 17.5 N lateral loads under static conditions were applied to the models to simulate the occlusal forces following the concept of lingualized occlusion. All conditions were created using a finite element software program. Maximum von Mises stress at the level of the attachments and at the bone support foundation interfaces were compared in all 12 models. The flexing of the mandible and the attachments were also compared qualitatively. Results: Stress on these models was analyzed after the given loading condition. The results showed that the model with three freestanding mini dental implants and flexible acrylic attachments showed the lowest von Mises stress and flexing, while the models with four freestanding mini dental implants and O‐ring attachments showed the highest von Mises stress. Conclusion: Three freestanding mini dental implants with flexible acrylic attachment systems supporting an overdenture were better choices than four mini dental implants with O‐ring attachment systems, which showed the maximum flexing and stress values in this qualitative comparison.     

locator种植覆盖义齿在下颌无牙颌修复中的应用

目的：探讨locator附着体种植覆盖义齿在下颌无牙颌修复中的临床应用效果。方法：对12例下颌无牙颌患者,每名患者下颌植入2枚种植体,共24枚,3~4个月后完成locator附着体覆盖义齿修复。术后2年期间进行随访。结果：24枚种植体均无松动,骨无明显吸收,患者对义齿咀嚼及固位满意。结论：locator附着体固位的种植覆盖义齿是下颌无牙颌患者理想的修复方式。     

Influence of Attachment Systems on Load Transfer of an Implant-Assisted Maxillary Overdenture

PURPOSE: This photoelastic study compared the load transfer characteristics of 2 retention mechanisms in an implant-assisted overdenture prosthesis. MATERIALS AND METHODS: Four implants were incorporated into a photoelastic model of a moderately resorbed edentulous human maxilla. Two retention mechanisms were studied by changing components on the same model and the palateless overdenture. The retention mechanisms studied were bar splint with anterior clip and distal resilient attachments, and solitary ball/O-ring attachments. Loads, ranging from 1.4 to 14.4 kg, were applied to the palatal incline of central incisors and buccal incline of premolars with and without balancing contacts. Stresses developed around all the implants under each loading condition were photographed in the field of a circular polariscope. RESULTS: With both retention mechanisms, protrusive and laterotrusive loads without balancing contacts caused instability of the overdenture, producing minimal stress around the implants in the supporting structure. High intensity stresses indicating intrusion of the posterior implants were noted when the bar/distal resilient attachment overdenture had balancing contacts for protrusive and laterotrusive loads. The posterior implants of ball/O-ring attachment overdenture exhibited high intensity stresses indicating not only intrusion, but also bending, when the occlusion was balanced. CONCLUSIONS: Balanced occlusion was required in both retention mechanisms for stability of the implant-assisted overdenture when clinically acceptable loads were applied. The protrusive and laterotrusive loads were not distributed equitably in either mechanism, since highest stresses occurred at the posterior implants.