钴铬合金铸造可摘局部义齿卡环折断后激光焊接的临床应用

目的探讨钴铬合金铸造可摘局部义齿卡环折断后的一种新的临床处理方法和程序。方法8例卡环折断义齿采用激光焊接进行修理。应用普通藻酸盐材料连同可摘局部义齿一起取印模,超硬石膏灌注模型。结果在保留旧义齿主体结构的情况下进行焊接修理后,义齿均就位顺利。经过15~24个月随访,均未再次折断,修理后的戴用时间均长于修理前的戴用时间。结论激光焊接修理可摘局部义齿铸造卡环折断的方法,不仅完全能够满足患者对舒适、节省、快速的要求,而且质量可靠。     

纯钛铸造支架可摘局部义齿的临床应用

目的 探讨太铸造支架可摘局部义齿的临床应用。方法 选择６２名缺牙患者，采用精 铸造技术，用ＤＥＮＴＡＵＲＵＭ Ｔｉ２２材料进行铸造支呆可摘局部义齿修复，制作修复体６８件，患者戴用后１～２年作临床观察。结果 钝钛铸造支架义齿质轻，基托薄，卡环具有弹性，固位好，戴用舒适，易适应。结论 临床上使用此种金属制作的义齿具有很好的修复效果，值得推广应用。     

隐形义齿600例临床观察

隐形义齿又称弹性义齿，是由一种弹性的活性塑料制成，其具有柔韧性和半透明性，与牙龈颜色协调，且不需要金属卡环。我科自１９９６年～１９９８年共为６００例牙列缺损的患者制作６５４件隐形义齿，并进行了初步的临床疗效观察。１材料与方法１．１一般资料１．１．１患...     

弹性树脂卡环铸造部件结合式义齿的临床应用

牙列缺损是口腔修复临床的常见和多发性缺损畸形[1]。在牙列缺损的诸多修复方法中，活动义齿是牙列缺损最常见的方法，但常规可摘局部义齿，存在美观和发音上的不足，许多患者难以接受。弹性树脂卡环铸造部件结合式义齿，是应用弹性树脂材料制作前牙及双尖牙区卡环、基托，而连接杆、支托、磨牙区卡环及小连接体等非弹性部位，采用铸造方法制作的可摘局部义齿。作者从1998年到2000年，对60例患者62件义齿用此方法修复，临床应用证明，能获得满意的修复效果。现介绍如下：1.材料和方法1.1一般资料修复60例患者共62件义齿，男性24例，女性36例…     

三种活动义齿基牙及其支持组织表面的应力分析

目的 :比较在局部可摘义齿修复中锻造卡环、铸造卡环和隐形义齿对基牙牙周组织表面应力的差异。方法 :分别用三种不同卡环的固位方式制作双侧游离端局部义齿 ,施加垂直压力 ,测试不同位点牙周组织表面应力。结果 :三种卡环义齿对基牙根尖部牙周组织的作用力无显著差别 ,而对牙颈部牙周组织及支承牙槽嵴的应力差异显著 (P <0 .0 5 ) ,具有统计学意义。结论 :在相同加载条件下 ,铸造卡环对牙颈部牙周组织产生的应力最大 ,隐形义齿对支承牙槽嵴产生的应力最大。     

弹性卡环基托义齿制作可能出现的问题及对策

弹性卡环基托义齿（隐形义齿）采用高弹性、抗折力强,生物安全性好的高分子弹性材料。材料和色泽与龈组织接近,有一定的透明性并有仿血管的纤维,替代了传统义齿的基托和金属卡环部分。该义齿的基托薄而富于弹性,患者佩戴舒适;义齿的卡环亦由基托材料铸压形成,美观,誉为隐形义具,深受患者的欢迎。我科使用Ｖａｌｐｌａｓｔ弹性基托材料。为单个牙或多个牙缺失患者,也为整铸支架的可摘局部义齿制作弹性基托和部分固位卡环,已完成５４例,取得了良好的效果。现提出制作工艺中可能出现的一些问题,和个人处理意见,并作了讨论,仅供参…     

弯制卡环与铸造卡环对龈下微生物的影响

目的了解卡环戴入前后基牙龈下微生物变化,考察弯制卡环与铸造卡环对龈下微生物影响的差异.方法检查戴牙前、戴牙后1周、1月和3月,弯制卡环和铸造卡环所在基牙龈下可培养细菌总量及革兰氏阴性菌构成比的变化.结果与戴牙前相比,戴牙后1周、1月和3月龈下可培养细菌总量及革兰氏阴性菌构成比均明显增加,差异有统计学意义(P＜0.05),戴牙后1月,弯制卡环与铸造卡环所在基牙龈下革兰氏阴性菌构成比有统计学差异(P＜0.05).结论在本文观察期(3个月)内,卡环的戴入造成龈下微生物中革兰氏阴性菌构成比显著增加,弯制卡环与铸造卡环对龈下微生物中革兰氏阴性菌构成比的影响没有显著差异.     

隐形义齿结合铸造部件的临床应用

结合铸造部件的隐形义齿，是应用弹性树脂材料制作前牙及双尖牙区卡环、基托，而连接杆、颌支托、磨牙区卡环及小连接体等非弹性部位，采用铸造方法制作的可摘局部义齿，它既美观又有良好的固位效果。笔者从2002年～2005年，对110例患者132件义齿用此方法修复，临床应用证明，能获得满意的修复效果。     

焊接锻丝卡环在铸造支架中的应用体会

整体铸造支架可局部义齿由于强度高，体积小，较薄，戴用舒适，在可局部义齿中的应用越来越多。但由于其固位的铸造卡环比较粗大，尤其在口角区域设计此种卡环时，患自觉不美观，不舒适。自2002年以来，笔应用激光焊接技术将锻丝卡环焊接在铸造支架上，取得了较好的临床效果。     

牙周病患者经套筒冠义齿修复治疗后的回访调查

目的：通过问卷调查表对牙周病患者戴用套筒冠义齿后的主观感觉进行分析研究。方法：选择牙周病患者15例，其中男性7例，女性8例，平均年龄为48岁。共制作套筒冠义齿24件，其中上颌10件，下颌14件。通常于戴牙后1个月，患者基本适应戴用义齿。通过问卷调查表，了解患者戴用义齿后的适应情况，对义齿的满意程度及咀嚼功能的变化等方面。结果：所有患者每天坚持戴用义齿，并保持较好的清洁习惯；80％以上的患者对各自所戴用的套筒冠义齿表示满意，90％以上的患者感觉义齿对说话和进食无影响；大多数患者认为饮食结构与治疗前相比发生了变化，咀嚼功能变好。结论：调查结果说明牙周病患者对套筒冠义齿的修复治疗效果是满意的。结合牙周临床观察指标及X光片，说明套筒冠义齿对牙周病有较好的治疗效果。     

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.     

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.     

Stress distribution of abutments and base displacement with precision attachment- and telescopic crown-retained removable partial dentures

Five types of removable partial dentures (two attachment dentures, two telescopic dentures and one clasp denture) were designed. The two attachment dentures were retained by the rigid-precision attachments with or without a stabilizing arm, and the two telescope dentures were retained with cone telescope crowns with or without cross-arch stabilization. The stresses acting on abutment teeth and denture bases and the movements of denture bases were investigated, and the influences of denture design were clarified. The stress acting on a terminal abutment tooth retained by a rigid-precision attachment or cone telescopic crown was larger than that acting on a terminal abutment tooth retained by a clasp. The attachment dentures tended to concentrate more stress at the terminal abutment tooth than did the telescopic dentures. The stress of denture base of an attachment denture and a telescopic denture was less than that of a clasp denture. There was no difference between the stresses of attachment and telescopic dentures. The displacement of the denture base tended to be less when the denture was designed with a rigid connection for the retainer and with cross-arch stabilization.     

Esthetic considerations with removable partial dentures

The reduction in partial edentulism that has occurred due to successful preventive procedures and the predictable use of osseointegrated implants has reduced the need for removable partial dentures. However, for a variety of reasons, many patients can continue to benefit from partial denture therapy; and these patients deserve the best esthetic result possible. The primary esthetic objection to removable partial denture therapy is the unsightly display of the clasp assemblies. This article describes three strategies that can be used by the discriminating clinician to eliminate the display of the clasp assembly and provide an esthetic and functional removable prosthesis.     

Clinical evaluation of abutment teeth of removable partial denture by means of the Periotest method

Prosthodontics should be one of the means of establishing conditions for the maintenance of periodontal health. The forces applied to the abutment teeth and their effects are very important considerations in the design and construction of the removable partial dentures. This 6-month follow-up clinical study evaluated the degree of mobility of abutment teeth of distal extension and tooth supported removable partial dentures by using Periotest. Two types of clasp design were selected for evaluation. In cases with unilateral and bilateral distal-extension, a clasp design including a T clasp of Roach retentive arm, a rigid reciprocal arm and a mesial rest were used. For the abutments of tooth-supported removable partial dentures, a second clasp design with a cast circumferential buccal retentive arm, a rigid reciprocal clasp arm and a rest adjacent to the edentulous ridges was selected. A total of 68 abutment teeth was analysed. Periotest values were made at the time of denture placement (control) and at 1, 3 and 6 months after the denture placement. The statistical analysis was performed using Friedman test. All analysis was performed at a 0.05 level of significance. The results revelled that no significant changes in tooth mobility were observed during the 6-months follow-up (P > 0.05). In conclusion, our findings suggest that adequate oral hygiene instructions, careful prosthetic treatment planning and regular recall appointments play an important role in preventing changes in abutment tooth mobility caused by removable partial denture placement.     

Ecologic changes in the oral cavity caused by removable partial dentures.

1. The introduction of a removable partial denture into the oral cavity adversely affects the prevailing ecologic situation in terms of plaque formation. 2. The rehabilitative effect of a removable partial denture may be safeguarded by controlling plaque formation by strict personal hygienic measures on the part of the patient. In particular, proximal surfaces adjacent to denture bases should be pointed out to patients as surfaces to which they must give special attention. 3. Simplification of the design of removable partial dentures can reduce their damaging potentialities. 4. Further prophylactic measures, such as topical application of fluorides and perhaps other chemicals, should also be taken.     

Complications and failures in removable partial dentures: a clinical evaluation

The design of removable partial dentures (RPDs) is an important factor for good prognostication. The purpose of this study was to clarify the effectiveness of denture designs and to clarify the component that had high rates of failure and complications. A total of 91 RPDs, worn by 65 patients for 2-10 years, were assessed. Removable partial dentures were classified into four groups: telescopic dentures (TDs), ordinary clasp dentures (ODs), modified clasp dentures (MDs) and combination dentures (CDs). The failure rates of abutment teeth were the highest and those of retainers were the second highest. The failure rates of connectors were generally low, but they increased suddenly after 6 years. Complication and failure rates of denture bases and artificial teeth were generally low. Complication and failure rates of TDs were high at abutment teeth and low level at retainers. Complication and failure rates of ODs were high at retainers.     

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。     

The effect of partial denture connectors on gingival health

The effect on the gingiva of a variety of relationships of a removable partial denture connector to the gingival margin was investigated in 10 subjects. Acrylic resin baseplates were designed incorporating a variety of relationships of the connector to the gingival margin. The appliances were worn for a 12 hour period daily, for 21 days. At baseline and at days 7, 21 and 49, plaque index, gingival index and probing pocket depth measurements were recorded, and subgingival plaque samples were examined using darkfield microscopy. No increase in plaque accumulation was detected in any area at any time interval. There was a significant increase in gingival index at day 21 in areas where the appliance covered the gingival margin. Small increases in probing pocket depth were recorded at day 21, there being no difference between any of the test areas. Baseline values were re-established by day 49. No significant differences were detected in the percentage of motile organisms or spirochaetes counted in the subgingival plaque samples collected from any area. It was concluded that deterioration in gingival health occurred rapidly following the insertion of a removable appliance, and that coverage of the gingival margin, irrespective of the degree of gingival relief, had a detrimental effect.