Statistical analysis of fabrication of fixed and removable partial dentures]

A statistical survey based on laboratory records was performed on the number of fixed and removable partial dentures fabricated at the dental hospital of Tokyo Medical and Dental University from April 1 to September 30, 1997. A comparison was also performed with a previous survey, which had been carried out in 1986, in order to detect any change and possible alterations in the near future. From the findings of this statistical survey, the conclusions were as follows: 1. A total of 2,478 fixed and removable partial dentures were fabricated during the six month period in 1997. 2. The 3-unit fixed partial denture (bridge) was most common (63.1%) and the number of bridges decreased as the number of units increased. 3. For the single missing tooth, a fixed bridge was more popular (81.0%) than a removable partial denture. 4. For two missing teeth, there was no difference between the number of fixed bridges and removable partial dentures. 5. The percentage of fixed and removable partial dentures, which were not covered by health insurance, decreased to a large extent in comparison with the survey in 1986.     

Clinico-statistical observation of various prosthetic restorations at the Prosthetic Department, Asahi University Hospital. 4. Circumstances concerning prosthetic method for missing teeth for the duration from April 1986 to March 1987

The statistics for prosthetic restorations used for missing teeth at the Prosthetic Department of Asahi University Hospital from April 1986 to March 1987 were compared with those obtained for an earlier period (April 1983 to March 1984). Fixed bridges and removable partial dentures constituted the majority of the prosthetic restorations for posterior teeth. Fixed bridges were twice more frequently used for anterior teeth during this period than during the previous period. For a single missing tooth, fixed bridges amounted to 90% and removable partial dentures to 10%, as they did in the previous period. For two or more missing teeth, the use of fixed bridges was some what increased compared to the previous period. As in the previous report, the use of so-called one-tooth denture was most frequent for missing lower first molar. For bridges, the average number of missing teeth and that of abutment teeth were 1.3 and 2.4 respectively. Bridges for one missing tooth with two abutment teeth were most frequently used. For removable partial dentures, the average number of missing teeth and that of abutment teeth were 6.1 and 2.8 respectively. Removable partial dentures for two missing teeth with two abutment teeth were most frequently used. Full cast crowns were most frequently used for bridge retainers, followed by facing crowns. Facing crowns were used more than twice as frequently during this period as they were during the previous period.(ABSTRACT TRUNCATED AT 250 WORDS)     

Rotational path removable partial denture: an esthetic alternative

Missing teeth can be replaced using any of a number of methods. Patients may choose to replace missing teeth with a prosthesis that is either removable, fixed, or retained with implants. When it is necessary to replace anterior or posterior teeth, a properly designed and fabricated rotational path removable partial denture can be both successful and esthetically pleasing to the patient. However, while a patient's functional and esthetic needs can be met successfully, rotational path removable partial dentures can be more demanding for the laboratory technician to fabricate and for the dentist to seat in the mouth. Rotational path removable partial dentures frequently are overlooked as a viable means of treating missing teeth. This article reviews the principles of rotational path removable partial dentures, as well as their categories, advantages, and disadvantages, in the hope that more dentists will consider them when the need arises.     

A comparative evaluation of masticatory efficiency of fixed and removable restorations replacing mandibular first molars

In replacing a missing mandibular first molar, removable and fixed partial dentures were constructed for each of ten subjects. Masticatory function tests with peanuts were made before, immediately after, and one week and one month subsequent to insertion of both types of prostheses.Masticatory performance, the number of strokes, and chewing time until swallowing were similar with the removable and fixed partial dentures. One month after insertion, a slight but statistically significant decrease in the total time of mastication was observed.The electromyogram of the anterior belly of the temporal muscles made during peanut chewing was also analyzed. It was found that, as a result, the rhythm of the masticatory movement after the cementation of fixed partial denture was more regular and that the duration of movement bursts became shorter than that with the removable partial denture.     

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.     

Single tooth replacement with a removable partial denture

The indication of removable partial dentures in cases of single tooth replacement is limited. This is due to a number of disadvantages closely connected to the use of removable partial denture. An often applied use is that of a mucosa-borne transitional acrylic denture to improve patients aesthetics until the definitive denture can be made. Acrylic dentures may be indicated as a definitive denture when limited financial resources are available. A metal frame removable partial denture can be applied to lengthen a shortened dental arch or in specific cases in which fixed partial dentures are not the preferable treatment option. The success of the treatment with a removable partial denture is highly dependent on the follow-up service and the oral hygiene awareness.     

Statistical investigation of lower distal free-end denture design used by general practitioners in Japan.

Tooth loss eventually occurs in most adults, and masticatory function is restored with a prosthesis such as a fixed crown & bridge, removable partial denture (RPD), or complete denture according to the extent of loss. For the RPD there are different structural-element combinations and different designs that can be applied to the same loss pattern, so that the effect and prognosis vary. Results from a statistical investigation of removable distal free-end dentures in Japan suggested that in many cases, insufficient consideration was given to mechanical stability and protection of remaining peripheral tissue in the design of removable partial dentures.     

Cantilevered fixed partial dentures in a geriatric population: preliminary report

This study has shown that treatment with distally extending cantilever fixed partial dentures is a favorable alternative to treatment with removable partial dentures in elderly patients with reduced dentition. In patients with anterior teeth and one or two premolar teeth remaining in the mandible, sufficient occlusal stabilization for a maxillary complete denture was provided by a two- or three-unit cantilever fixed partial denture. A pronounced improvement in chewing function and stability of the maxillary denture was expressed, even by patients who were previously well adapted to wearing removable partial dentures.     

Statistical analysis of fabrication of indirect single restorations]

A statistical survey based on laboratory records was performed on the number of indirect restorations fabricated at the dental hospital of Tokyo Medical and Dental University from April 1 to September 30, 1997. A comparison was also carried out with a previous survey, which had been carried out in 1986, in order to detect any change and possible alterations in the near future. Based on the results of this statistical survey, the conclusions were as follows: 1. A total of 9,126 indirect restorations were fabricated during the six month period in 1997; among them, 8,007 (87.7%) restorations were covered by health insurance and 1,119 (12.3%) restorations were not. 2. The most common restoration was the cast post and core (28.6%), followed by full crowns (18.5%) and removable partial dentures (15.6%). On the other hand, the least number were post crowns (0.03%) and resin jacket crowns (0.2%). 3. When making a comparison with the data in 1986, an increase in the number of removable partial dentures and a decrease in the number of inlays were the most distinctive features. 4. For anterior teeth, resin-veneered crowns were most common, especially for lower teeth. The percentage of restorations, which were not covered by health insurance, decreased from 45.0% (in 1986) to 12.3% (in 1997).     

北京口腔医院技工中心11年修复体加工情况的统计分析

目的客观评估不同种类修复体的应用情况,为临床应用、资源优化配置和科研课题选择等提供参考信息。方法收集首都医科大学附属北京口腔医院技工中心2002-2012年的工作月报和制作数据,以299953件修复体为研究对象,统计冠桥固定修复体、种植固定修复体、可摘局部义齿、全口义齿等主要修复体类别的数量,分析发展趋势。结果活动类修复体构成比呈逐年下降趋势,固定类修复体逐年成为主要修复类型。全口义齿与胶连活动义齿缓慢减少,4种铸造支架活动义齿均增长。贵金属烤瓷固定义齿的制作量增长速率较快,种植体固定修复体一直呈稳定增长趋势,全瓷固定修复体制作量自开展后加速增长。贵金属全冠修复体制作量呈整体增长,成为铸造全冠修复体主要材料类型,而普通钴铬全冠修复体制作量则持续缓慢降低。结论固定类修复体占主导地位,活动类修复体逐年降低,各种材料修复体均有不同程度的起伏,但都有各自的临床需求,其中贵金属、全瓷、种植类需求量增长最为明显,预示未来修复体发展的方向。     

Correlations between self-ratings of denture function and oral health-related quality of life in different age groups

This study aimed to assess the correlation between self-rated denture function and oral health-related quality of life (OHRQoL) in different age groups. Subjects' OHRQoL was measured using the Oral Health Impact Profile, and self-ratings of denture function were assessed on a Likert-type scale for patients with fixed and removable partial dentures in 3 age groups (N = 253). For subjects with fixed partial dentures, all correlations were significant for the younger patients but not for higher age groups, whereas the opposite was true for subjects with removable partial dentures. The importance of self-perception of denture function in OHRQoL is different in various groups of patients, depending on age and dental status.     

Rotational path removable partial denture (RPD): conservative esthetic treatment option for the edentulous mandibular anterior region: a case report

It can be esthetically and financially daunting for patients to lose teeth in an anterior region of the mouth. For these patients, traditional treatment options presented in the past have included fixed partial denture, implants, and conventional removable partial denture (RPD). For patients faced with financial, anatomical, and/or esthetic limitations, the edentulous region can be restored successfully with a rotational path RPD. Rotational path RPD designs have often been overlooked by the dental profession due to its complex concepts involving the prosthetic design and sensitive laboratory techniques. With better understanding of the concepts and design, the dental clinician can deliver the highest esthetic outcome in compromised areas in which other treatment options may often face limitations. This paper reviews the method used to esthetically design and plan a posterior-anterior rotational path RPD in an edentulous mandibular anterior region for a patient missing the mandibular incisors. CLINICAL SIGNIFICANCE: Due to inadequate understanding of the mechanics of rotational path RPDs, many clinicians have not adapted the application of this advantageous prosthesis. When correctly designed and fabricated, the rotational path RPD provides improved esthetics, cleanliness, and retention for patients who may not be suitable candidates for implants or fixed partial dentures in tooth-supported edentulous regions.     

Time to survival for the restoration of the shortened lower dental arch

Removable partial dentures may adversely affect remaining tissues and have a low prevalence of use. This randomized controlled trial was designed to compare the time to survival of cantilever resin-bonded fixed partial dentures and conventional removable partial dentures to restore shortened lower dental arches. We randomly allocated 25 male and 35 female patients (median age, 67 years) to fixed or removable partial denture groups of 30 persons, matched for age and sex. Survival of the prostheses was assessed, based on listed criteria, at each review or when problems arose. Although the removable partial denture group required rather more maintenance visits, the difference in survival rates was not statistically significant (hazard ratio = 0.59, with 95% CI 0.27, 1.29). In the absence of significant differences in five-year survival, the reported advantages of fixed partial dentures, including reduced maintenance frequency, offer positive support for the use of resin-bonded fixed partial dentures.     

Precision metal occlusal surfaces for removable partial dentures

The prosthodontist is often limited in developing the desired occlusal pattern when integrating removable partial dentures with natural dentitions or fixed partial dentures. A technique that allows the development of an esthetic, accurate metal occlusal surface for a removable partial denture is described. The occlusion developed allows an occlusal harmony with the removable partial denture that is not possible with stock denture teeth or metal occlusal surfaces developed with stock denture teeth.     

Interim removable partial dentures: two case reports

For the partially edentulous patient, an interim denture can provide acceptable short-term function and esthetics by replacing missing teeth and tissues until a definitive restoration can be performed. This article presents two cases that required interim removable partial dentures to maintain function, phonation, and esthetics until clinical conditions allowed for the fabrication of definitive dentures.     

老年人可摘局部义齿修复对基牙的影响

目的:分析研究老年人可摘局部义齿修复后对基牙的影响,探讨其原因及预防措施。方法:对95例牙列缺失后的老年人行冷弯卡环固位式可摘局部义齿修复,记录和比较戴可摘局部义齿后基牙和非基牙的龋坏率和缺失率,用χ2检验分析其结果有无差异,并对影响基牙的原因进行分析。结果:戴用可摘局部义齿5a后,基牙的患龋率(17.38%)显著高于非基牙(7.10%);因牙折、牙周病松动及龋坏无法保留而拔除的基牙缺失率(27.01%)也显著高于非基牙(7.79%)(P<0.01)。结论:冷弯卡环固位可摘局部义齿修复后在一定程度上可增加老年人基牙的患龋率和缺失率。     

老年人牙缺失临床修复治疗的分析

目的了解老年修复患者的口腔情况及修复特点。方法对1 166例60岁以上老年人牙缺失患者作修复治疗,分析缺牙及修复情况。结果1 166例患者平均缺牙10.25颗。牙缺失数上领>下领,磨牙>双尖牙>切牙>尖牙。1 166例患者中1 120例作可摘义齿修复,其中游离端缺失约占58%0 46例作固定义齿修复。结论老年修复患者具有缺牙数目多,游离端缺失多,余牙磨耗严重,食物嵌塞多,余留牙松动及残根多等特点;修复以可摘义齿为主,可适当行固定义齿修复。修复治疗时尽量发挥尖牙、已治疗的残根及健康第三磨牙的作用。     

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.     

可摘局部义齿卡环疲劳性能测试方法及研究现状

牙列缺损是老年人的常见口腔疾病,会给患者的生活造成诸多不便,不仅影响患者的咀嚼、发音和口颌系统健康,也会对患者的心理健康和生活质量产生不同程度的负面影响.牙列缺损常见的修复方式有种植义齿、固定义齿和可摘局部义齿.目前,虽然选择种植义齿的患者日趋增多,然而仍有很多患者由于身体原因、经济原因等无法选择种植义齿修复.可摘局部...     

Glass fiber reinforcement in repaired acrylic resin removable dentures: preliminary results of a clinical study.

The clinical usefulness of continuous E-glass partial fiber reinforcement of acrylic resin removable dentures was evaluated an average 13 months after the insertion of the fibers. Twelve removable complete dentures and ten removable partial dentures with a history of recurrent fracture were selected for this study. The partial fiber reinforcement was incorporated into the denture at the time of repair. One complete denture and one removable partial denture fractured in the region of reinforcement during the examination period. These fractures were most likely caused by faulty placement of the fiber reinforcement in the denture in the dental laboratory. In six dentures, new fractures occurred in regions without partial fiber reinforcement. The results revealed the importance of both the correct positioning of the partial fiber reinforcement in the denture and the use of accurate laboratory techniques.