设置缓冲间隙对下颌种植覆盖总义齿应力分布的影响

目的 分析设置缓冲间隙对下颌种植覆盖总义齿应力分布的影响。方法 应用三维有限元方法模拟正中开闭口运动中下颌种植覆盖总义齿的受力状态,分析冲击载荷下缓冲间隙的设置对义齿应力分布的影响。结果 缓冲间隙的设置可以降低种植体内部、种植体软硬组织界面和义齿基托内应力的峰值,最易引起种植体侧方界面骨吸收的压应力峰值降低了约５２％。结论 设置缓冲间隙有利于保护种植体界面软硬组织的健康,防止义齿基托折裂,提高种植     

总义齿、覆盖义齿和种植覆盖义齿修复后患者满意度的比较研究

目的：比较总义齿（CD）、覆盖义齿（COD）和种植覆盖义齿（IOD）修复后的患者满意度。方法：选取CD、COD和IOD修复后的患者各14例，对三组患者分别进行满意度的问卷调查。结果：三组患者对义齿总的满意度的差异没有显著性，对咀嚼功能的满意度IOD组显著高于CD组。三组患者戴用旧义齿的经验没有显著差异。义齿的松动和食物受限情况IOD组明显少于CD组，而义齿修复后的牙槽嵴疼痛和感觉咀嚼无力的情况三组间没有显著差异。结论：IOD修复后患者对咀嚼功能的满意度较CD修复的患者高，出现的问题少，是一种较好的修复无牙颌的方法。     

种植体磁性固位下颌覆盖总义齿的应用

目的：探讨种植体磁性固位下颌覆盖总义齿的临床应用。方法：在下颌全口缺牙且伴有牙槽骨重度吸收患的前牙区选择性植入2－4颗BLBC种植体，4－5个月后全口义齿修复，藏牙3周后，在种植体上旋转磁固位的上部结构并安装永磁体在相对应的义齿组织面内。分别测量患使用种植体一磁固位系统前后的固位力、咀嚼效率。结果：下颌总义齿的固位力、咀嚼效率在使用磁性固位体前、后均存在显性差异。结论：种植体支持的磁固位覆盖总义齿，对于改善下颌全口缺牙且伴有牙槽骨重度吸收患的咀嚼功能有一定作用。     

下颌总义齿的种植固定修复3例体会

临床上经常见到下颌无牙颌患者,由于牙槽骨严重吸收,虽经托牙修复,咀嚼功能受到严重影响,患者迫切要求改善咀嚼功能,种植义齿修复满足了患者的要求。我科采用完全由种植体支持的下颌总义齿修复３例,效果满意,现报告如下。材料和方法本组共３例,男２例,女１例,年龄６０～６４岁,都因牙周病龋病而致下颌牙缺失。种植体由北京莱顿生物材料有限公司提供,柱状,表面喷涂ＨＡ。一、术前准备１－印模,求咬合关系,排牙,制作托牙,如患者原有托牙,可用琼酯包埋复制托牙,以备作手术导板用。２－Ｘ线检查：将直径均匀一致的钢球两粒用…     

冲击载荷下下颌种植覆盖总义齿与下颌常规总义齿应力分布特点的比 …

目的 比较分的了下颌种植覆盖总义齿及下颌常规总义齿的应力分布特点,方法 应用ＣＴＲ发描法建立下颌种植覆盖总义齿及下颌常总义齿的三维有限元模型,并采用更为接近Ｈｅ力性质的冲击载荷,将咀嚼动态过程引入有限元研究,比较分析两种义齿应力分布特点,结果（１）种植内部应力最大值出现侧方种植体内,骨界面及软组织界面应力最大值出现于侧方种植体远中舌侧皮质骨及粘骨膜内;（２）下颌种植覆盖总义齿了种植体的应用降低了剩     

冲击载荷下下颌种植覆盖总义齿与下颌常规总义齿应力分布特点的比较研究

目的比较分析下颌种植覆盖总义齿及下颌常规总义齿的应力分布特点。方法应用ＣＴ扫描法建立下颌种植覆盖总义齿及下颌常规总义齿的三维有限元模型,并采用更为接近　力性质的冲击载荷,将咀嚼动态过程引入有限元研究,比较分析两种义齿应力分布特点。结果①种植体内部应力最大值出现于侧方种植体内,骨界面及软组织界面应力最大值出现于侧方种植体远中舌侧皮质骨及粘骨膜内;②下颌种植覆盖总义齿种植体的应用降低了剩余牙槽嵴表面压应力峰值;③下颌常规总义齿及种植覆盖总义齿基托应力峰值分别出现于前牙区舌侧基托及侧方种植体顶部基托处。结论①下颌种植覆盖总义齿机械并发症易发生于侧方种植体内及侧方种植体骨界面处;②种植体的应用有利于保护剩余牙槽嵴,减缓骨吸收;③二种义齿基托易折部位不同。     

总义齿的复制

牙列缺失患者,行总义齿修复后,一适应,习惯,成为生活所必需。对于设计合理,制作精良的总义齿,尤为珍爱。病人常需按照原样再做一副,有的病人则在第一次总义齿修复时,要求做2副,以便备用。尤其是经过多年使用的旧义齿,从其(牙合)平面,牙弓形态,边缘伸展与宽度、唇面外形、髁突的位置关     

磁性附着体加带弹性的翼式基托在覆盖总义齿中的应用

磁性固位体现已成为改善口腔颌面修复体固位的重要手段。作者采用磁性附着体加带弹性的翼式基托覆盖总义齿,对上颌前牙区牙槽嵴明显前突,而双侧口角附近区域均仅有少数条件欠佳的牙齿存留的患者进行修复,既避免了拔牙,缩短了修复时间,又能达到良好的固位、咀嚼、美观等效果。1.材料和方法1.1 材料 Z-1型闭合磁路磁性附着体(第四军医大学口腔医学院研制),规格为4.5mm×4mm×3mm,固位力约950g;直径为1.0mm牙用不锈钢丝;常规制作全口义齿所需的材料等。1.2 病例选择 上颌前牙区牙槽嵴明显前突,单颌双侧均仅有1颗或1颗以上存留牙(包括残冠残根…     

即刻全负重种植总义齿的临床评价

目的:观察总义齿即刻负重种植修复的临床效果,以及应用中的关键问题.方法:3例患者共计30个种植体,即刻负重总义齿修复,观察时间2年.结果:3例患者的种植总义齿修复体临床效果良好,3个病例全部取得成功.结论:选择适当的病例,即刻负重总义齿种植修复可成功应用于临床,近期效果满意.     

种植体支持的磁性固位与快套式下颌覆盖总义齿的比较

目的:比较种植体支持的磁性固位与快套式固位覆盖总义齿的临床应用情况。方法:22例无牙下颌患者按种植覆盖总义齿固位方式的不同分为二组,在戴牙二年后、四年后检测患者满意度、种植体周骨质吸收程度。结果:二组义齿的戴牙后满意度除固位力外无显著差异,但种植体周骨质吸收程度存在高度显著性差异。结论:种植体支持的磁性固位下颌覆盖总义齿种植体周的骨质吸收较少。     

Oral function in subjects with overdentures supported by osseointegrated implants

Abstract – Nine subjects treated with overdentures on osseointegrated implants in the mandible were functionally evaluated before and after treatment. The last recordings were performed 1 yr after treatment. The evaluation comprised a subjective and a clinical examination. Measurements of bite force and of chewing efficiency were also performed. The bite force was measured during gentle biting, biting as when chewing and biting with maximal effort. Almonds, were used as test food. All subjects improved subjectively as well as clinically after treatment. The bite force during gentle biting increased on average from 17.3 N before treatment to 24.0 N 1 yr after treatment. A corresponding improvement of biting as when chewing was also found, from on average 24.0 N before to 38.7 N after treatment. The maximal bite force increased from on average 74.6 N at the baseline examination to 131.5 N at the 1-yr follow-up. The chewing efficiency improved from C_i=4 (Median value) before treatment to C_i=2.8 (Median value) after treatment. It is concluded that treatment with an overdenture supported by osseointegrated implants in the mandible improves oral function compared to the situation before treatment.     

Mandibular overdentures supported by two or four endosseous implants. A 5-year prospective study

OBJECTIVE: The aim of this 5-year prospective comparative study was to evaluate treatment outcome (survival rate, condition of hard and soft peri-implant tissues, patient satisfaction, prosthetic and surgical aftercare) of mandibular overdentures supported by two or four implants. MATERIAL AND METHODS: Sixty edentulous patients with a mandibular height between 12 and 18 mm participated. Thirty patients were treated with an overdenture supported by two IMZ implants (group A) and 30 patients were treated with an overdenture supported by four IMZ implants (group B). Standardised clinical and radiographic parameters were evaluated 6 weeks after completion of the prosthetic treatment and after 1, 2, 3, 4 and 5 years of functional loading. Prosthetic and surgical aftercare was scored during the evaluation period. RESULTS: One implant was lost (group A) during the healing period. There were no significant differences with regard to any of the studied clinical or radiographic parameters of the peri-implant tissues between the groups. None of the patients reported sensory disturbances in the lip or chin region. No differences in satisfaction were observed between the groups. With regard to aftercare, there was a tendency of a greater need of prosthetic interventions in group A, while correction of soft-tissue problems was restricted to patients of group B. CONCLUSION: There is no difference in clinical and radiographical state of patients treated with an overdenture on two or four implants during a 5-year evaluation period. Patients of both groups were as satisfied with their overdentures.     

Mandibular overdentures supported by two or four endosseous implants: a 10-year clinical trial

Objective: The aim of this 10-year clinical trial was to evaluate the treatment outcome (condition of hard and soft peri-implant tissues, patient satisfaction, surgical and prosthetic aftercare) of mandibular overdentures supported by two or four implants.
Materials and methods: Sixty edentulous patients with a mandibular height between 12 and 18 mm participated. Thirty patients were treated with an overdenture supported by two IMZ implants (group A) and 30 patients were treated with an overdenture supported by four IMZ implants (group B). Standardised clinical and radiographic parameters were evaluated 6 weeks after completion of the prosthetic treatment and after 1, 5 and 10 years of functional loading. Prosthetic and surgical aftercare was scored during the evaluation period, as well as patient satisfaction.
Results: There were no statistically significant differences with regard to any of the studied clinical or radiographic parameters of the peri-implant tissues between the groups. In addition, no differences in satisfaction and aftercare were observed between the groups.
Conclusion: There is no difference in the clinical and radiographical state of patients treated with an overdenture on two or four implants during a 10-year evaluation period. Patients of both groups were evenly satisfied with their overdentures and received the same amount of aftercare. For reasons of cost-effectiveness, a two-implant overdenture is advised for patients with a Cawood classes IV–VI resorption of the mandible and complaints concerning retention and stability of the lower denture.     

A prospective study of single stage surgery for implant supported overdentures

OBJECTIVEs: To investigate the clinical and psychological outcomes with ball attachment supported mandibular overdentures on Branemark implants placed in a single stage surgical approach. MATERIAL AND METHODS Sixteen edentulous patients aged 32-74, with atrophic (flat) mandibular residual alveolar ridges, and a history of having difficulty coping with technically adequate mandibular dentures made within the last 2 years were recruited. Mark II Branemark implants were placed using a single stage surgical technique with healing abutments placed at time of surgery. Mandibular complete dentures were modified by relieving the areas over the abutments and a resilient liner was placed. After a period of 3 months, healing abutments were replaced with ball abutments and new complete dentures were made and the patients followed for a period of 2 years. Patients completed the General Health Questionnaire (GHQ) and answered further questions relating to the functional and psychological impact of complete denture wearing before treatment and 3 months after the dentures were provided. Patients additionally completed the GHQ 2 years after overdenture insertion. RESULTS: Six patients suffered from loss of one of their two implants in the first 2 years after placement. Three of the implants had failed to osseointegrate, which was detected at initial loading 3 months after placement. General Health Questionnaire scores were statistically significantly reduced after treatment and the improvement was maintained over 2 years. Responses to the functional and psychological questions were similarly improved. CONCLUSION: Single stage surgery led to a higher rate of implant failure than expected. Patients showed significant psychological health benefits from the treatment provided.     

Two-center clinical trial of implant–retained mandibular overdentures versus complete dentures – chewing ability

Abstract This study is a two-center clinical trial with the aim to assess the treatment effects of implant-retained mandibular overdentures versus conventional complete dentures. Treatment had been assigned according to a balanced allocation method. The following criteria were used to enhance the comparability of the treatment groups: age, gender, the edentulous period of the mandible, the number of previously made mandibular dentures, the number of years having worn the present mandibular denture and the symphyseal bone height. 151 patients with severely resorbed mandibles participated in the study, they were treated at two centers. Ninety-one patients received an implant-retained mandibular overdenture (IRO) and 60 patients a conventional complete denture (CD). Since some patients refused the allocated treatment the “Intention To Treat” principle was applied. This implies that patients are evaluated in the originally allocated treatment group regardless of the actual treatment they received. Patient's experiences were evaluated before treatment and I yr after insertion of the new dentures. Results before treatment showed that both treatment groups were comparable: they were dissatisfied with their mandibular denture and they could hardly chew tough or hard foods. One year after insertion of the new dentures the IRO-group was satisfied with their mandibular denture, whereas only one third of the CD-group was satisfied. With respect to the chewing ability the IRO-group scored significantly better than the CD-group (P0.0001).     

Implant‐retained mandibular overdentures compared with complete dentures; a 5‐years' follow‐up study of clinical aspects and patient satisfaction

The aim of this prospective randomized controlled clinical trial was to evaluate and compare clinical aspects and satisfaction during the first year following treatment and consecutively the change in treatment during the next 4 years of follow-up. Patients were allocated to one of the following treatment modalities: an implant-retained overdenture (IRO-group, 2 endosseous implants, n = 61) or a complete denture (CD-group, n = 60). One year after placement of the denture, unsatisfied patients of the CD-group got the opportunity for a retreatment including an implant-retained overdenture. In the IRO-group 4 implants were lost during the first year and again 4 implants were lost during the next 4 years (survival rate: 93%). All patients could be re-operated successfully. In the CD-group 14 patients (23%) chose an implant-retained overdenture after 1 year. Patients of the IRO-group were significantly more satisfied than patients of the CD-group after 1 year (satisfaction score 8.3 versus 6.6, scale 1-10) and after 5 years (7.4 versus 6.4). From this study it can be concluded that endosseous implants have a high survival rate after 5-years' follow-up. Satisfaction score of the IRO-group is diminishing in time, probably because patients get used to an improved situation. After 5 years, the mean satisfaction score of the CD-group (including patients who got implants) was still lower than of the IRO-group, in spite of the opportunity to a retreatment and have implant-retained overdentures.     

Mandibular overdentures supported by two or four endosteal implants: A prospective, comparative study

The aim of this prospective study was to evaluate the effect of the number of implants supporting a mandibular overdenture on the condition of the peri-implant tissues. Sixty edentulous patients (Cawood class V–VI) participated in this study. After randomization, thirty patients were treated with an overdenture supported by two IMZ implants (group A) and thirty patients with an overdenture on four IMZ implants (group B). The implants were inserted in the anterior region of the mandible. After three months overdentures were constructed, supported by round bar and clip attachments. A standardized clinical and radiographic evaluation was performed 0, 6 and 12 months after insertion of the denture. One implant was lost (group A) during the healing period. There were no significant differences with regard to any of the studied clincial or radiographic parameters of the peri-implant tissues, neither were significant differences found between the lateral and central implants in group B. None of the patients reported a sensory change in lip or chin region. From this study it is concluded that there seems to be no need to insert more than two endosteal implants to support an overdenture, however, long-term prospective studies are needed to support this notion.