纯钛铸造支架可摘局部义齿在肯氏I类牙列缺损修复中的临床应用

目的：观察纯钛支架可摘局部义齿用于修复双侧牙列游离端缺损后的临床效果。方法：选择58例肯氏I类缺牙患者，用DENTAURUMTD2材料进行铸造支架可摘局部义齿修复，随访1-5年，对基牙状况、义齿使用情况等进行观察。结果：纯钛支架可摘局部义齿质量轻，异物感小，义齿配戴舒适，固位力持久，咀嚼功能恢复良好，无异味、无口腔黏膜过敏症状。结论：纯钛支架可摘局部义齿适用于肯氏I类缺牙的修复治疗，获得了良好的临床效果。     

纯钛铸造支架可摘局部义齿在肯氏Ⅰ类牙列缺损修复中的临床应用

目的:观察纯钛支架可摘局部义齿用于修复双侧牙列游离端缺损后的临床效果。方法:选择58例肯氏I类缺牙患者,用DENTAURUM Ti22材料进行铸造支架可摘局部义齿修复,随访1-5年,对基牙状况、义齿使用情况等进行观察。结果:纯钛支架可摘局部义齿质量轻,异物感小,义齿配戴舒适,固位力持久,咀嚼功能恢复良好,无异味、无口腔黏膜过敏症状。结论:纯钛支架可摘局部义齿适用于肯氏I类缺牙的修复治疗,获得了良好的临床效果。     

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目的    建立下颌KennedyⅠ类可摘局部义齿的三维有限元模型,为其设计提供生物力学基础。方法    在2008年6月山东大学附属千佛山医院口腔科常规体检人群中选取1名男性志愿者,年龄55岁,下颌双侧后牙游离缺失,余留前牙无拥挤,咬合关系正常。通过螺旋CT扫描与计算机辅助设计（CAD）技术及Unigraphics、MSC.MARC软件结合的方法,建立下颌KennedyⅠ类可摘局部义齿的三维有限元模型。结果    建成双侧后牙游离缺失的下颌骨及其可摘局部义齿的三维有限元模型,共有单元36 968个,节点9553个,模型可以根据需要任意进行旋转和缩放。 结论    CT扫描与CAD技术联合应用建立双侧后牙游离缺失的下颌骨及其可摘局部义齿三维有限元模型的方法切实可行。     

Occlusal plane modification of an existing maxillary complete denture prior to removable partial denture construction: a case report

Success in fabricating removable partial dentures, Kennedy Class I and Class II in particular, is highly dependent on proper orientation of the occlusal plane. The closer to the ideal, the better the prosthesis will function and provide proper esthetics and phonetics. This case report presents the diagnosis and occlusal modification of an existing maxillary complete denture to improve the patient's masticatory function with the fabrication of a removable partial denture.     

Mandibular implant-supported removable partial denture with distal extension: a systematic review

Summary The aim of this article is to investigate patient satisfaction, survival rate of implants, and prosthetic complications or maintenance for rehabilitation with removable partial dentures associated with implants in mandibular Kennedy class I and II cases. A systematic literature review was conducted by three independent reviewers including articles published from January 1981 through September 2011. Medline and Cochrane Library electronic databases were used in addition to hand searching to assess clinical outcomes for mandibular implant-supported removable partial denture with distal extension. This review yielded 1751 records that were narrowed down to 5. The studies revealed implant survival rates ranging from 95% to 100% with one failure reported of 98 implants. The removable partial dentures associated with implant in mandibular free-end arches showed some complications and need of repair for relining, pitting of the healing abutment, replacement of resilient component of the attachment, damage in framework, screw loosening and damage in acrylic denture base. Patient satisfaction was evaluated through a five-point questionnaire, and results ranged between 4·12 and 5·0, considering 1 as the least favourable situation. The literature review showed increase in patient satisfaction and high survival rates of implants associated with mandibular removable partial dentures with distal extensions. However, some complications and need of prosthetic repair were reported. Although this treatment approach could represent a low-cost and beneficial rehabilitation for free-end mandibular ridges, the lack of controlled and randomised well-designed clinical trials suggests further studies with more representative samples to validate the outcomes of this treatment modality.     

Modalities of Treatment for the Combination Syndrome

A series of destructive changes occurring in the jaws of patients wearing a complete maxillary denture opposed by a mandibular distal extension removable partial denture have been described as the combination syndrome. However, the syndrome does not occur in all patients. Those patients who have not developed signs of the combination syndrome and whose mandibular anterior teeth are well preserved and not overerupted may be treated conservatively with a mandibular removable partial denture. A properly designed removable partial denture that distributes occlusal stresses over hard and soft tissues minimizes the risk of developing the combination syndrome. Nevertheless, the overdenture seems to provide a more predictable prognosis, especially for patients who already have the combination syndrome or whose mandibular anterior teeth are structurally or periodontally compromised or overerupted. The treatment modality is determined by the apparent potential of the patient to develop the combination syndrome and by the condition of the remaining mandibular anterior teeth.     

三种固位体义齿修复Kennedy第一和第二类牙列缺损疗效观察

目的评价太极扣义齿、精密附着体义齿和卡环固位体义齿修复Kennedy第一类和第二类牙列缺损的临床效果。方法收集Kennedy第一类和第二类牙列缺损修复患者823例,随机选择其中太极扣义齿、精密附着体义齿和卡环固位体义齿修复患者各63例,电话联系随访复查,检查患者基牙牙周状况及义齿组织面下黏膜,通过问卷调查获取患者的主观评价,并将结果进行对比研究。结果患者对太极扣义齿、精密附着体义齿的主观评价高于对卡环固位体义齿的主观评价;在舒适度、美观方面太极扣义齿优于精密附着体义齿。戴用3种义齿患者的口腔检查结果差异无统计学意义。结论太极扣义齿比较适合修复Kennedy第一类和第二类牙列缺损。     

纯钛铸造支架可摘局部义齿的临床应用对比研究

目的：对比研究纯钛铸造支架、钴铬合金支架、塑料基托可摘局部义齿修复的临床疗效。方法：选择90件肯氏I类设计修复义齿,分别用三种义齿修复方法,戴用后半年～2年进行临床观察。结果：钝钛铸造支架叮摘局部义齿质量轻,佩戴舒适,咀嚼功能良好。结论：纯钛铸造支架可摘局部义齿可获得良好的临床效果。     

不同设计形式RPD对支持组织应力分布影响的光弹分析

目的:探讨分裂式设计与RPI设计制作的钴铬合金铸造支架RPD修复KennedyⅠ类缺损对支持组织应力分布的影响,为优化义齿设计提供实验依据。方法:分别以分裂式设计和RPI设计两种设计形式的钴铬合金铸造支架RPD修复下颌牙双侧游离缺失,用三维光弹应力冻结切片技术测试义齿加载后对基牙和缺牙区牙槽骨的应力分布,并加以分析比较。结果:钴铬合金分裂式设计的铸造支架RPD承受压力沿基牙牙体长轴传导,基牙远中所受扭力较小。结论:对于KennedyⅠ类牙列缺损,钴铬合金分裂式设计的铸造支架RPD使支持组织受力均匀、合理,减小了基牙受到的扭力,达到基牙保护的目的,是一种值得推广的设计。     

The Effect of Removable Partial Dentures on Alveolar Bone Resorption: A Retrospective Study with Cone‐Beam Computed Tomography

Purpose: The aim of this study was to compare vertical and horizontal mandibular alveolar bone resorption by measuring bone morphological variation in Kennedy Class II removable partial denture (RPD) wearers and non‐wearers using cone‐beam computed tomography (CBCT). Materials and Methods: In total, 124 sites in the CBCT scans of 62 (29 RPD non‐wearers, 33 RPD wearers) Kennedy Class II patients were analyzed retrospectively. Three‐dimensional representations of the mandible with superimposed cross‐sectional slices were developed with the CBCT scans to evaluate the mandibular alveolar height and width by measuring distances between the mandibular canal, mylohyoid ridge, alveolar crest, and lower border of the mandible in four regions (eight sites) of Kennedy Class II non‐wearers and wearers of RPDs. Results: Mandibular alveolar bone height and width were significantly lower in edentulous sites when compared with dentate sites in both Kennedy Class II non‐wearers and wearers of RPDs (p < 0.05). Additionally, mean vertical and horizontal mandibular bone resorption was significantly higher in RPD wearers than in non‐wearers (p < 0.05). Conclusions: Vertical and horizontal alveolar bone resorption was found to be higher in the RPD wearing patients when comparing the dentate and edentulous sites.     

Clinical evaluation of removable partial denture rest seat adaptation

The clinical relationship between the removable partial denture cast occlusal rest and the corresponding rest seat was examined. Under the conditions of the study, it was found that rests of mandibular Class I and II removable partial dentures fit significantly better than those of mandibular Class III and IV prostheses. No significant difference was noted between similar types of maxillary removable partial dentures in this regard. In evaluating the fit of specific portions of the occlusal rest, it was found that the marginal ridge zone was more closely adapted to the rest seat than other zones for all types of removable partial dentures. However, contact, as defined in this analysis, was found to exist on a random basis in all four quadrants of the occlusal rests evaluated. In spite of this fact, one fifth of the occlusal rests did not contact the opposing rest seat at any point. Improved fit with length of service was not substantiated by a cross-sectional analysis. Suggestions were made to assist the clinician in achieving a better fit between the framework and dentition in removable partial dentures.     

Prevalence of the 'combination syndrome' among denture patients

The prevalence of symptoms associated with "combination syndrome" were documented in 150 maxillary complete denture wearers. The five alveolar ridge changes that are most consequential to denture wearing and most difficult to correct surgically were found in 7% of the population studied. However, these changes were found in 24% of patients who have natural mandibular anterior teeth opposing complete maxillary dentures. This rate did not differ significantly between patients who do and do not wear a mandibular removable partial denture.     

The role of single immediate loading implant in long class IV Kennedy mandibular partial denture

Background: The treatment of long‐span Kennedy class IV considers a prosthodontic challenge. This study evaluated the integrity of principle abutments in long Kennedy class IV clinically and radiographically, when rehabilitated with conventional metallic partial denture as a control group and mandibular partial overdentures supported with single immediately loaded implant in symphyseal as a study group. Material and Methods: Twelve male patients were divided randomly allotted into two equal groups. First group patients received removable metallic partial denture, whereas in the second group, patients received partial overdentures supported with single immediately loaded implant in symphyseal region. The partial dentures design in both groups was the same. Long‐cone paralleling technique and transmission densitometer were used at the time of denture insertion, 3, 6, and 12 months. Gingival index, bone loss, and optical density were measured for principle abutments during the follow‐up. Results: A significant reduction in bone loss and density were detected in group II comparing with group I. Gingival index had no significant change (p‐value < 0.05). Conclusion: A single symphyseal implant in long span class IV Kennedy can play a pivotal role to improve the integrity of the principle abutments and alveolar bone support.     

Effect of implant-supported or retained dentures on masticatory performance: a systematic review

STATEMENT OF PROBLEM: While subjective patient-based measures have been increasingly recognized as critical outcomes for prosthodontic treatment, there continues to be a need to validate for patients what changes in masticatory function can be expected with the provision of new implant-supported or retained dentures. PURPOSE: The purpose of this review was to evaluate the critical factors impacting change in masticatory performance following the provision of new implant-supported or retained dentures. MATERIAL AND METHODS: Information retrieval followed a systematic approach using PubMed and the Cochrane Library. English articles published from 1966 to June 2007, in which the masticatory performance of subjects with implant-supported or retained dentures was assessed by objective methods and compared to performance with conventional dentures, were included. Ratings of the evidence provided in each article followed United States Agency for Healthcare Research and Quality recommendations. RESULTS: From 281 articles identified, 18 peer-reviewed articles met prespecified criteria for inclusion. Specific outcomes of significance identified by these articles rated as level II are: (1) fixed implant-supported partial dentures do not provide significant improvement in masticatory performance compared to conventional removable partial dentures for Kennedy Class I and II partially edentulous mandibles; (2) the combination of a mandibular implant-supported or retained overdenture (IOD) and maxillary conventional complete denture (CD) provides significant improvement in masticatory performance compared to CDs in both the mandible and maxilla for a limited population having persistent functional problems with an existing mandibular CD due to severely resorbed mandible; and (3) the type of implant and attachment system for mandibular IODs has a limited impact. Specific outcomes of significance identified by articles rated as having a moderate level of evidence (level III) are: (1) mandibular fixed implant-supported complete dentures provide significant improvement in masticatory performance compared to mandibular CDs in subjects dissatisfied with their CDs; and (2) implant-supported mandibular resection dentures have an advantage over conventional dentures in masticatory performance on the defect side of the mouth. CONCLUSIONS: Objective benefits in masticatory performance of implant-supported or retained dentures compared to conventional dentures are limited to a mandibular IOD in edentulous patients with a resorbed mandible and/or difficulty adapting to CDs.     

A comparison of patient's satisfaction between complete and partial removable denture wearers

OBJECTIVES: The aim of this study was to compare satisfaction between complete denture (CD) and Kennedy Class I removable partial denture (RPD) wearers. MATERIALS AND METHODS: A total of 156 CD and 112 RPD wearers took a part in this study. From the primary group of the examined patients, only those whose RPDs and CDs were assessed as excellent or very good by the dentist, took a part in this study. Patients graded satisfaction of their dentures by using an analogue scale from 1 to 5 (1=unsatisfactory; 5=excellent). RESULTS: Both CD and RPD wearers were mostly satisfied with their dentures (the distribution of the scores of the patients' assessments was skewed towards the highest scores; more than half of the patients scored all the examined variables to the best score category). Complete Denture wearers were significantly more satisfied with chewing, speech and retention of maxillary denture than RPD wearers (P<0.05). Removable partial denture wearers were significantly more satisfied with the retention and the comfort of wearing mandibular denture (P<0.05). There was no significant difference between CD and RPD wearers for general satisfaction with their dentures, aesthetics and comfort of wearing maxillary denture (P>0.05; N.S.). CONCLUSIONS: A majority of CD and RPD wearers were satisfied with the dentures. CD wearers were more satisfied with speech, chewing and retention of maxillary denture, while RPD wearers were more satisfied with the retention and the comfort of wearing mandibular denture. Different groups of denture wearers have to make significant, but different adjustments to wear their dentures successfully.     

软衬材料在下颌双侧游离缺失修复中的应用研究

目的:观察软衬材料在下颌双侧游离缺失可摘局部义齿中的应用效果。方法:选择38例牙槽嵴重度吸收的下颌双侧游离缺失患者,随机分为两组。实验组在可摘局部义齿中引入软衬材料对义齿进行衬垫处理,对照组接受常规可摘局部义齿修复。检测两组义齿戴用1个月、1年及2年时的咀嚼效率,同时采用满意度问卷调查获取患者的主观评价。结果:与对照组比较,实验组义齿各个时期的咀嚼效率均获得明显改善(P<0.05),舒适程度及咀嚼功能的满意度亦高于对照组(P<0.05)。结论:软衬材料的应用可提高下颌双侧游离缺失可摘局部义齿的满意度,改善患者的咀嚼效率,取得良好的修复效果。     

Displacement of mandibular removable partial denture bases by tongue movements during speech.

PURPOSE: The purpose of this study was to evaluate denture base displacement caused by tongue movements during speech. MATERIALS AND METHODS: Ten patients with new Kennedy Class I mandibular removable partial dentures participated in this study. All prostheses were made according to a standardized protocol. Denture base displacements when speaking a test sentence were measured with a computer-aided device that was developed for this purpose. It included 4 Hall sensors, mounted on a paraocclusal splint and magnets, embedded in the denture bases. Vertical and transverse base displacements were calculated from Hall voltages. Clasp retention was measured with a dynamometer. RESULTS: Mean displacements were 145 microns seating, 72 microns unseating, 87 microns buccally, and 74 microns lingually. Seating and unseating displacements differed statistically significantly in absolute values. Mean clasp retention was 2.5 N. No correlation was found between clasp retention and unseating base displacements. CONCLUSION: Tongue movements during speech induced only minimal displacements in the dentures investigated. Additionally, tongue activity was found to be denture stabilizing rather than denture displacing in this study.     

Resilient Attachments as an Alternative to Conventional Cast Clasp Removable Partial Denture: 3-Year Follow-up

The present clinical report describes the prosthodontic management for a patient with uncontrolled bleeding and diabetes mellitus treated with a maxillary complete denture and a mandibular partial fixed dental prosthesis designed to interface with a removable cast framework partial denture retained by 2 ERA attachments. This approach was undertaken to improve both retention and stability of the distal extension Kennedy Class I removable partial denture. The rehabilitation provided better anterior esthetics than if treated with a conventional clasp retained removable partial denture, by employing a simple, practical design and offering a significant biomechanical advantages, restoring both oral health and function. Thus, this treatment modality, involving an ERA system and transfixation in fixed crowns, is an effective treatment and can be indicated as a clinical alternative for edentulous and partially edentulous patients with systemic disorders or for patients in economic situations that might preclude implant-based rehabilitation.

     

Prevalence of the ‘combination syndrome’ among denture patients

The prevalence of symptoms associated with “combination syndrome” were documented in 150 maxillary complete denture wearers. The five alveolar ridge changes that are most consequential to denture wearing and most difficult to correct surgically were found in 7% of the population studied. However, these changes were found in 24% of patients who have natural mandibular anterior teeth opposing complete maxillary dentures. This rate did not differ significantly between patients who do and do not wear a mandibular removable partial denture.     

ERA附着体义齿修复Kennedy Ⅱ类牙列缺损的临床评估

目的临床研究Kennedy Ⅱ类牙列缺损采用ERA附着体义齿进行修复的效果。方法27例对原先普通可摘局部义齿不满意的Kennedy Ⅱ类牙列缺损患者,均采用ERA附着体义齿进行修复。结果经过6个月~1年时间随访,100%的患者表示对该义齿的固位性能,咀嚼效能,舒适程度,以及装卸的方便程度感到满意。义齿损坏1例经过简单修理后患者满意。2例牙槽嵴吸收在1/3内患者经过6~12个月观察,未见明显基牙牙槽骨吸收。结论ERA附着体义齿进行修复Kennedy Ⅱ类牙列缺损患者,满意度明显优于普通可摘局部义齿。临床观察还提示ERA义齿尚不会造成短期基牙牙槽骨损害。