纯钛支架义齿与钴铬合金支架义齿修复效果的比较

目的评估纯钛铸造支架义齿的临床应用效果。方法为168例肯氏Ⅰ、Ⅱ类牙列缺损的患者制作71例纯钛支架义齿和97例钴铬合金支架义齿,通过比较两组患者临床试戴情况、初戴义齿适应期的调改情况、义齿性口炎的发生情况以及满意度,评估纯钛铸造支架义齿的临床修复效果。结果纯钛支架义齿比钴铬合金支架义齿就位顺利、调改少、患者满意度高,并且义齿性口炎的发生率低。结论纯钛铸造支架义齿与传统的钴铬合金铸造支架义齿相比临床修复效果好。     

铸造Twin-Flex卡环修复KennedyⅡ类牙列缺损的临床应用

目的研究整体铸造法制作的Twin-Flex卡环在KennedyⅡ类牙列缺损修复中的使用效果。方法15例KenendyⅡ类牙列缺损患者,应用铸造支架材料整体铸造Twin-Flex卡环进行活动义齿修复,评价义齿的美学效果,固位、支持及稳定性。结果 15例患者,采用整体铸造法制作的Twin-Flex卡环,KennedyⅡ类牙列缺损的末端基牙避免了唇颊侧卡环的暴露,美学效果良好,义齿固位、支持及稳定效果良好。结论整体铸造法制作的Twin-Flex卡环应用于KennedyⅡ类牙列缺损修复,符合游离端设计的基牙及牙槽骨生物力学要求,可取得较好的美学效果及临床应用效果。     

铸造支架结合弹性树脂可摘义齿修复的临床观察

目的：探讨弹性树脂与铸造支架联合修复牙列缺损的临床效果。方法：132例缺牙患者,共187件联合式义齿修复体。Kennedy一类修复36件,Kennedy二类修复27件,Kennedy三类修复91件,Kennedy四类修复33件。通过1～4年的观察,从形态和功能、固定和稳定、颜色和美观以及对义齿的满意程度进行临床效果评价。结果：187件义齿中160件具有良好的美观效果,颜色满意,感觉舒适,满意率达85.56%。结论：弹性树脂与铸造支架结合式义齿是一种美观、舒适、对基牙预备较少的可摘局部义齿修复形式,但Kennedy一类、二类、四类缺损应谨慎选用。     

可摘局部义齿

可摘局部义齿支架三维CAD方法的初步研究;种植体支持对Kennedy l类可摘局部义齿应力分布的影响;牙列重度磨耗对面高度的影响；SD锁式附着体修复单侧多数后牙游离缺失的应用研究;ERA附着体义齿修复KennedyⅡ类牙列缺损的临床评估;     

改良冷弯卡环与铸造支架联合应用修复牙列缺损的疗效观察

目的观察改良冷弯卡环联合铸造支架可摘局部义齿修复的临床效果。方法使用成品不锈钢圆丝锻制,配合扁丝弯制钳弯制成半圆形卡环臂、圆形卡环肩部及连接体、扁圆过度卡环体的改良冷弯卡环,与钴铬铸造支托、基托联合应用修复牙列缺损。并对90件改良冷弯卡环联合铸造支架可摘局部义齿戴入后追踪观察2年,了解义齿使用情况和基牙健康状况,并将其与钴铬合金支架义齿、传统冷弯卡环塑料基托义齿的修复效果对比。结果 2年后改良冷弯卡环联合铸造支架义齿基牙状况良好,不良症状明显低于其他两组义齿。结论改良冷弯卡环联合铸造支架可摘局部义齿具有良好的功能,可以获得良好的修复效果。     

种植体上部不同结构对下颌游离端义齿应力分布的影响

目的:观察不同上部结构的种植体支持可摘局部义齿修复下颌KennedyⅠ类牙列缺损时的应力和位移。方法:使用软件GeoStar(COSMOSM 2.85,SRAC,USA)建立4个种植体-天然牙联合可摘义齿修复下颌KennedyⅠ类牙列缺损的三维有限元模型,比较不同上部结构时种植体周围骨组织、基牙牙周膜、基托下黏膜的最大等效应力及基托下黏膜组织的位移变化。结果:有种植体支持时,单冠形式的种植体周围骨组织最大等效应力最大;缓冲型套筒冠的基牙牙周膜最大等效应力、基托下黏膜最大等效应力和位移值最大;微型太极扣种植体周围骨组织最大等效应力、基牙牙周膜最大等效应力和黏膜的最大等效应力及位移值均最小。缓冲型套筒冠种植体周围骨组织最大等效应力小于非缓冲型套筒冠,但基牙牙周膜最大等效应力、基托下黏膜最大等效应力和位移则大于非缓冲型。结论:选用种植体-天然牙联合支持修复远中游离端牙列缺损时,种植体上部结构采用微型太极扣作为附着体联接形式是最佳选择。     

钛合金铸造支架可摘局部义齿临床疗效观察

目的 观察用钛合金铸造金属支架进行可摘局部义齿修复的临床疗效.方法 2003～2006年制作45件钛合金铸造支架可摘局部义齿,戴入后追踪观察2年,了解义齿使用情况及基牙健康状况. 1年后将其与48件钴铬合金支架及塑料基托义齿的修复效果对比.结果 1年后钛合金支架义齿功能良好率为93.3%,基牙健康状况良好;不良症状明显低于钴铬合金支架及塑料基托义齿.结论 钛合金铸造支架可摘局部义齿具有良好的功能,适合于治疗义齿的临床应用.     

下颌KennedyⅡ类牙列缺损冠外附着体义齿基牙牙周状况对支持组织应力分布的影响

目的探讨不同基牙牙周状况下,下颌后牙单侧游离缺损冠外附着体义齿支持组织的应力分布情况。方法建立下颌KennedyⅡ类牙列缺损冠外附着体义齿修复时基牙牙周健康和基牙牙周吸收的三维有限元模型,分析垂直载荷下基牙牙周状况不同时,基牙牙周组织及缺牙区牙槽嵴的von Mises应力分布。结果基牙数目相同的条件下,与牙周健康的模型相比,牙周吸收的模型第二前磨牙的最大应力升高了约30%,牙周最大应力升高了约10%,缺牙区牙嵴的最大应力升高了36%和14%。对于牙周吸收的模型,基牙数目从两颗增加到三颗时,义齿支持组织的应力值无明显降低。结论在下颌单侧游离缺损修复中,末端基牙牙周部分吸收1/3即可导致基牙牙周组织及缺牙区牙嵴的应力明显增加,增加基牙数目并不能有效地降低义齿支持组织的最大应力值。     

钴铬合金铸造支架可摘局部义齿的临床疗效(附1032件义齿的临床分析)

目的：观察钴铬合金铸造支架可摘义齿的临床疗效。方法：随访１９８８年～１９９６年间８６８例戴用钴铬合金铸造支架可摘义齿计１０３２件的患者，以义齿功能和基牙健康状况作为评价指标。结果：１年～２年义齿功能良好率为９７．６％，基牙健康率为９７．３％；３年～４年义齿功能良好率为９４．２％，基牙健康率为６８．１％；５年～８年义齿功能良好率为８６．５％，基牙健康率为４８．２％。结论：钴铬合金铸造支架可摘局部义齿具有良好修复效果。     

不同固位形式可摘局部义齿对支持组织应力分布的研究

目的:探讨附着体义齿与常见可摘局部义齿修复单侧游离端缺失对支持组织应力分布的影响.方法:分别以磁性附着体、RPI卡环组、联合卡环组三种固位形式的可摘局部义齿修复下颌单侧游离端缺失,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应力分布,并与基牙不戴义齿时载荷下的应力比较.结果:磁性附着体对54|基牙和缺牙区的牙槽骨应力稍大于RPI,只占54|基牙应力的48%,且对基牙近、远中应力基本相等;联合卡环对基牙牙槽骨应力最小,对缺牙区牙槽骨应力最大.结论:磁性附着体义齿修复单侧游离端缺失能够达到RPI义齿功能效果,特别适合于对美观和舒适要求较高者,不主张使用仅靠单侧固位的联合卡环组义齿.     

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。     

The mandibular first premolar as an abutment for distal-extension removable partial dentures: a modified clasp assembly design

Sound mandibular first premolars can be used as sole abutments for bilateral distal-extension removable partial dentures, if the denture is designed to minimise the torque applied to the abutment teeth. A simplified modification of the conventional torque-releasing clasp-assembly designs is suggested for these teeth. This modification entails a mesial rest on each abutment tooth connected to the distal proximal plate via a lingual bracing arm. A circumferential clasp arm is optional for buccal retention of the removable partial denture. As with conventional designs, the metal framework is designed to permit some rotational tissueward movement of the distal extension bases, yet not compromise the retention and stability of the prosthesis.     

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。     

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。     

改良杆卡式附着体与不同可摘局部义齿对支持组织应力分布的研究

目的探讨改良杆卡式附着体义齿与RPI卡环组、联合卡环组可摘局部义齿修复单侧游离缺失对支持组织的应力分布。方法在下颌47、46单侧游离缺失的环氧树脂模型上分别以改良杆卡式附着体、RPI卡环组、联合卡环组3种固位形式的可摘义齿修复,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应力分布。结果对基牙牙槽骨的应力：改良杆卡式附着体义齿〉RPI卡环组〉联合卡环组（P〈0．05）;附着体义齿对基牙的近、远中应力无显著性：差异（P〉0．05）;RPI卡环组义齿有猞支托处的应力大于无拾支托处的应力（P〈0．05）;联合卡环组对远中的应力大于近中（P〈0．05）。对缺牙区牙槽骨应力：改良杆卡式附着体与RPI卡环组均小于联合卡环组（P〈0．05）;附着体义齿、RPI对缺牙区牙从近中到远中的4个切片应力无显著性差异（P〉0．05）,联合卡环组远中大于近中（P〈0．05）。结论改良杆卡式附着体义齿有应力中断作用,各点应力分布较均匀。RPI固位的活动义齿应力主要分布在基牙上,缺牙区应力稍小。联合卡环组义齿对失牙区的应力最大,基牙上应力较小。     

Photoelastic Study of the Support Structures of Distal-Extension Removable Partial Dentures

Purpose: The double system of support, in which the distal-extension removable partial denture adapts, causes inadequate stress around abutment teeth, increasing the possibility of unequal bone resorption. Several ways to reduce or more adequately distribute the stress between abutment teeth and residual ridges have been reported; however, there are no definitive answers to the problem. The purpose of this study was to analyze, by means of photoelasticity, the most favorable stress distribution using three retainers: T bar, rest, proximal plate, I bar (RPI), and circumferential with mesialized rest.
Materials and Methods: Three photoelastic models were made simulating a Kennedy Class II inferior arch. Fifteen dentures with long saddles, five of each design, were adjusted to the photoelastic patterns and submitted first to uniformly distributed load, and then to a load localized on the last artificial tooth. The saddles were then shortened and the tests repeated. The quantitative and qualitative analyses of stress intensity were done manually and by photography, respectively. For intragroup analyses the Wilcoxon test for paired samples was used, while for intergroup analyses Friedman and Wilcoxon tests were used to better identify the differences ( p < 0.05).
Results: The RPI retainer, followed by the T bar, demonstrated the best distribution of load between teeth and residual ridge. The circumferential retainer caused greater concentration of stress between dental apexes. Stress distribution was influenced by the type of retainer, the length of the saddle, and the manner of load application.
Conclusions: The long saddles and the uniformly distributed loads demonstrated better distribution of stress on support structures.     

Load transfer characteristics of unilateral distal extension removable partial dentures with polyacetal resin supporting components

Background:  To photoelastically examine load transfer by unilateral distal extension removable partial dentures with supporting and retentive components made of the lower stiffness polyacetal resins.
Methods:  A mandibular photoelastic model, with edentulous space distal to the right second premolar and missing the left first molar, was constructed to determine the load transmission characteristics of a unilateral distal extension base removable partial denture. Individual simulants were used for tooth structure, periodontal ligament, and alveolar bone. Three designs were fabricated: a major connector and clasps made from polyacetal resin, a metal framework as the major connector with polyacetal resin clasp and denture base, and a traditional metal framework I-bar removable partial denture. Simulated posterior bilateral and unilateral occlusal loads were applied to the removable partial dentures.
Results:  Under bilateral and left side unilateral loading, the highest stress was observed adjacent to the left side posterior teeth with the polyacetal removable partial denture. The lowest stress was seen with the traditional metal framework. Unilateral loads on the right edentulous region produced similar distributed stress under the denture base with all three designs but a somewhat higher intensity with the polyacetal framework.
Conclusions:  The polyacetal resin removable partial denture concentrated the highest stresses to the abutment and the bone. The traditional metal framework I-bar removable partial denture most equitably distributed force. The hybrid design that combined a metal framework and polyacetal clasp and denture base may be a viable alternative when aesthetics are of primary concern.     

Veterans Administration Cooperative Dental Implant Study — Comparisons between fixed partial dentures supported by blade-vent implants and removable partial dentures. Part I: Methodology and comparisons between treatment groups at baseline

This study was conducted to determine whether fixed partial dentures supported by dental implants provide an acceptable alternative to conventional removable partial dentures in patients with Kennedy class I or class II edentulous conditions. The acceptability of the new treatment will be based on success rates, impact on the health of the remaining dentition, masticatory performance, patient satisfaction, and maintenance care and cost. The study was planned also to provide comparisons between two designs commonly used by dentists for fabricating removable partial dentures. The designs differed only in terms of the type of the retainer (clasp type) and tooth support (rest location).A total of 272 patients with Kennedy class I and class II edentulous conditions were assigned on a random basis to one of the treatment groups, 134 to receive a removable partial denture and 138 a fixed partial denture supported by a blade-vent implant. All of the patients were medically screened and met prespecified criteria for oral hygiene, bone support for abutment teeth, and size of the residual ridge.Thirty-four patients were eliminated from the study before completion of their treatment. An additional six patients with early implant failures were reentered in the study and followed up as a separate group. The remaining 232 patients received comprehensive dental care, including removable partial dentures for 118 and fixed partial dentures for 114 patients.A series of examinations, radiographs, masticatory performance tests, patient satisfaction, food selection questionnaires, and dietary history were completed before initiation of the treatment, 16 weeks after the insertion of an RPD or an implant, and thereafter at 6-, 18-, 36-, and 60-month intervals. In addition, patients were seen at 6-month intervals for a recall dental examination, oral prophylaxis, plaque instructions, radiographic survey of the implant, and any needed dental treatment.The randomization stratification approach produced two treatment groups with comparable age, number of remaining maxillary and mandibular teeth, type of opposing dentition, and percent of patients with Kennedy class I and class II edentulous conditions. The mean scores of bone support, tooth mobility, and sulcular depths of abutment teeth were also similar. Significant but comparable improvements in oral hygiene and sulcular depth occurred in the two groups after treatment. The periodontal health scores at the 16-week interval serve as the baseline to measure subsequent changes in periodontal health. This prospective longitudinal study with prespecified criteria for implant and removable partial denture failure should provide reliable estimates of failure rates, number and types of complications, maintenance care needs, and total costs for the two treatment modalities and the two RPD designs.     

Influence of clasp design of distal extension removable partial dentures on the periodontium of the abutment teeth

Three removable partial denture designs were investigated to determine the effect of minor connector configuration on the periodontal health of abutment teeth. Twenty-five patients wore three different removable partial dentures for 19 weeks each. The first removable partial denture placed a tilting force on the abutment teeth; the second was stress-releasing; and the third collected the least amount of plaque. Plaque accumulation, the condition of the periodontium, migration of the abutment teeth, deformation of the clasp arms, retention of the prosthesis, and patient preferences were assessed. The results demonstrated that the partial denture retentive design did not affect plaque formation. The prosthesis designed to place a tilting force on the abutment teeth appeared to cause the least mobility and migration of the abutments and had the greatest acceptance by the patients.