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1.
OBJECTIVES: The technique of resin-bonded bridgework is a well-accepted clinical technique to replace missing teeth. This study assesses the clinical performance of cantilevered resin-bonded bridgework provided in a university teaching hospital environment. METHODS: One-hundred and twelve patients who had a total of 142 cantilevered bridges were either examined or completed a questionnaire regarding their bridgework. The following data were recorded for each resin-bonded bridge: gender of patient, age at bridge cementation, date of initial cementation, tooth replaced, abutment(s) involved, and grade of clinician responsible for the provision of the bridge. Details of the incidence of debonding with date(s) and the subsequent treatment in relation to the debonded resin-bonded bridge were recorded. The subjects examined indicated their degree of satisfaction with their bridgework on a visual analogue scale. RESULTS: There were 112 patients with a total of 142 bridges, 116 (82%) maxillary and 26 (18%) mandibular. The mean length of clinical service was 36.2 months (s.d. 17.2 months). Only single pontics were included in the bridges, with almost half (49%) replacing a lateral incisor. Of the cantilever resin-bonded bridges studied, 88% remained bonded over the period of the study. A success rate of 94% is reported. CONCLUSION: This study confirms the clinical success of cantilever resin-bonded bridges particularly in the replacement of maxillary lateral incisors, maxillary premolar and permanent mandibular teeth.  相似文献   

2.
Loss of anterior maxillary teeth always results in bone resorption and loss of interdental papillae, and the resorption makes a single tooth replacement by a dental implant very difficult. When infections have been present and the patient's history shows previous surgery at the apex of the root, bone destruction is substantial, which results in an increased resorption defect, thereby further increasing the aesthetic and prosthetic problems. This paper describes the steps necessary for implant surgery and the prosthetics; a brief summary is provided. The quality and quantity of bone, along with the space available between the adjacent teeth, are the basic factors in treatment planning and determine the type of implant to be used. Some resorption and bone defects are usually present after a tooth extraction, and bone regeneration procedures can be performed either before or simultaneously with the implant placement, with numerous flap designs available. Soft tissue augmentation can be achieved by taking a connective tissue graft from the palatal side. Antirotational devices (eg, hex lock abutments) are necessary for all implants in single tooth replacement. Screw-retained abutments can be used in posterior areas and in angled positions in facial areas as well. With proper single tooth implant position, cementation of laboratory fabricated crowns can be considered.  相似文献   

3.
A two-dimensional finite element model was constructed to analyze the simulated mechanical behavior of a cantilevered fixed partial denture. The variations of the models were made by altering the degree of bone support, the number of splinted abutments, and the length of the pontics. High stress concentrations were observed around the connectors of the fixed prosthesis and the tooth closest to the cantilever. Reduced bone support increased the deflection and stress concentrations. There was reduction in displacement and stress concentration when the teeth were splinted together. To improve the prognosis of the fixed partial denture cantilever, the number of abutments should be increased and the number of pontics decreased.  相似文献   

4.
This paper outlines criteria which allow the clinician to identify endodontically treated teeth that can be restored with a high level of predictability. The intent of the article is not to preclude the restoration of teeth that do not meet these criteria; it is to provide a science-based approach for identifying those teeth with a high probability of long-term success upon restoration. For an endodontically treated tooth not requiring a post, the requirements are for biologic width + ferrule length, (i.e. 4.5 mm of supra-bony solid tooth--dentin a minimum of 1 mm thick after preparation). A tooth requiring a post needs, in addition, enough root length to allow a 4 mm apical seal and a post length--apical to the crown margin, equal to the length of the crown. It is essential to assess the functional loads to which the restored tooth would be subjected. Teeth that are endodontically treated, or are likely to be in future, should be avoided as abutments supporting precision attachment RPDs, distal extension RPDs or cantilever FPDs.  相似文献   

5.
The present study was performed to test the tendency for plaque and calculus build-up along the wire of different types of bonded orthodontic canine-to-canine retainers, whether the presence of such retainers causes any damage to the teeth involved, the failure rate of the retainers, and any changes in incisor alignment during a 3-year period of retention. The four test groups received either retainers made of thick plain wire bonded only to the canines (n = 11); thick spiral wire bonded only to the canines (n = 13); thin, flexible spiral wire bonded to each tooth (n = 11); or removable retainers (n = 14). Accumulation of plaque and calculus along the gingival margin, gingival inflammation and probing attachment level were scored in lingual areas from canine to canine at the time of fixed appliance removal and again 3 years after retainer insertion. Incisor irregularity was measured on plaster models made at the same time periods. Accumulation of plaque and calculus and development of caries along the wire were scored at follow-up. Retainer failures were recorded whenever they occurred. The results revealed no intergroup differences in changes between baseline and follow-up examinations or status along the retainer wire for any of the variables. Gingival inflammation and plaque accumulation were scored less frequently after 3 years in retention than at the time of debonding. No signs of caries were seen adjacent to the wire. Failures were observed of one, four and three of the fixed retainer types, respectively. These patients showed a greater increase in incisor irregularity than the other patients.  相似文献   

6.
Bridges at least with two types of retainers (adhesive frame-work, inlay, onlay, overlay, or crown) might be called fixed partial dentures with combined retainers. The aim of the present study was to compare the fixed partial dentures with combined retainers made at our clinic between 1986 and 1996. In our study the cumulative proportional survival of the combined bridges was found 80%. Examining the loss of the combined bridges it seems that in the first year 1% of the bridges came off. The rest was lost between 12th and 48th months.  相似文献   

7.
ME Mavili 《Canadian Metallurgical Quarterly》1997,39(4):353-9; discussion 359
Establishment of the best possible relationship between upper and lower teeth is very important when treating jaw fractures and orthognathic deformities in partially edentulous patients. Many surgeons use arch bars and acrylic splints for intermaxillary fixation (IMF) to obtain the best occlusal relationships after the operation. In patients with sufficient teeth, IMF is not so difficult to realize. However, in partially edentulous patients, the available teeth may not be sufficient to apply arch bars or splints. This paper describes a system for IMF of a partially edentulous jaw. Screws made of medical-grade titanium are implanted into the alveolar ridges where two or more teeth are missing. Arch bars or acrylic splints secured on these implants and available teeth can be used safely for IMF. In vitro axial pull-out tests demonstrated that these implants can withstand the traction forces generated by elastics. Five partially edentulous patients, three with mandibular fractures and two with orthognathic problems, were treated with these implants. All patients healed without any complications and with the best possible occlusal relationships.  相似文献   

8.
The aim of this retrospective study was to record patients' satisfaction with fixed metal ceramic bridges and crowns made by dental students and to evaluate the functioning and condition of the bridges and crowns clinically and radiologically. Out of the 60 patients treated at the Institute of Dentistry during 1984-85, 30 patients attended the follow-up examination (16 women, mean age 39, range 23-62 years and 14 men, mean age 44, range 26-65 years). The anamnestic data and data regarding treatment procedures were collected from the patient files. The patients had been supplied with 41 crowns and 24 bridges (mean 3.9 units, range 3-6 units), which included 61 abutments and 33 pontics or cantilever extensions (abutment/pontic ratio 1.85: 1). Marginal fidelity was unsatisfactory in 13% of the crowns and bridges and gingival bleeding and pockets of 4-6 mm were noted in 27% and 12% of cases, respectively. None of the subjects had caries in the abutments.  相似文献   

9.
This article presents prospective four-year prosthetic results of the placement of 432 posterior freestanding, conventionally cemented prosthetic tooth implants in posterior edentulous spaces using the Bicon Dental Implants system (Bicon Dental Implants). Over four years, 0.74 percent of the abutments loosened, 0.5 percent of the abutments fractured, and 2.47 percent of the crowns experienced porcelain fracture, (all porcelain fractures occurred at time of placement). This low rate of problems appears to make free-standing single-tooth implant restorations a reliable solution to treating posterior edentulism.  相似文献   

10.
For children with extensive caries of primary teeth, or with deformed or traumatised teeth, restoration with composite using a crown form gives excellent results. Strength is gained by full crown coverage. The aesthetics are very acceptable. The technique also allows primary teeth to be modified to resemble permanent teeth when these are missing and the primary teeth are being kept until more definitive treatment is provided. Caries is usually well controlled, and space loss due to further tooth breakdown is avoided.  相似文献   

11.
Absence of the maxillary lateral incisor creates an aesthetic problem which can be managed in various ways. The condition requires careful treatment planning and a consideration of the options and outcomes following either space closure or prosthetic replacement. Recent developments in restorative dentistry have warranted a re-evaluation of the approach to this clinical situation. Factors relating both to the patient and to the teeth, including the presenting malocclusion and the effect on the occlusion, are considered. This review considers the possible options: no treatment; orthodontic space closure with canine modification; space maintenance and replacement of the missing tooth with denture, bridge (adhesive and conventional), or implant.  相似文献   

12.
13.
Elastomeric expansion bearings are often restrained laterally by retainers on each side. The retainers are in the form of a concrete shear block, rolled steel angles, or welded plates. To allow for longitudinal temperature movements, the retainers are placed with a slight clearance (gap) from the elastomer. The gap introduces nonlinearity in the seismic analysis of the bridge and, therefore, is often ignored by designers for the sake of simplicity. This paper compares the seismic response of straight and skewed slab-girder single-span bridges under the conditions of zero gap and standard gap for the retainers. Nonlinear time-history analysis is employed to measure the seismic demand on retainers, elastomers, and pinned bearings in each case. The stiffness of end-diaphragms and elastomeric bearings is included in the analysis. It is shown that these relationships are nonlinear in nature and depend on the frequency content of the input motion. It is also proved that ignoring the nonlinearity in the seismic bridge model can lead to erroneous results that are unsafe to use.  相似文献   

14.
Root-form implants may be indicated for the replacement of missing anterior teeth. Occasionally fixtures are placed in a position inconsistent with proper tooth alignment. The new PreAngled Abutment (Dentsply/Implant Division, Encino, CA) addresses this problem and was used to successfully restore missing tooth numbers 7 and 8 for a patient that had two malpositioned implants.  相似文献   

15.
The aim of this study was to investigate the visibility of secondary caries in the gingivobuccal and gingivolingual corners of teeth restored with amalgam restorations. Standard Class II cavities were created in 15 orthodontically extracted mandibular premolar teeth, and the teeth were randomly divided into five groups of three teeth each. In four of the groups, a 1.0- or 1.5-mm cavity was prepared in the gingivolingual or gingivobuccal corner of the restoration. No lesions were created in group 5, the control group. The teeth were restored with amalgam. The teeth were adapted in the actual tooth space of 15 volunteers with one mandibular premolar missing. Radiographs of each patient were taken with the bisecting-angle technique and the bite wing technique. The radiographs were sorted at random and given to 15 members of the professoriate who were often involved in detecting caries and to 17 members who were not normally involved in detecting caries. The bitewing technique was found to be more reliable than the bisecting-angle technique in detecting secondary caries in gingivobuccal approximal corners (P < .05). It was also found that, in group 1, the bisecting-angle technique was more reliable than the bitewing technique in detecting caries in gingivolingual corners (P < .05). No significant differences were found in the correct evaluation of radiographs between the faculty who were normally involved in the detection of caries and those who were not.  相似文献   

16.
The mesial rest-I-bar concept is the most important contribution to clasp partial denture design in the last 30 to 40 years. When used with discernment in situations where it is not contraindicated, it constitutes an excellent design for extension-base removable partial dentures. It has become the design of choice for an increasing number of dentists. Use of the three elements that make up the clasp assembly does not necessarily insure that the clasp will function as intended. There are situations for which it should not be used. Unless adequately adjusted after framework construction as well as during the maintenance program, the beneficial effects may be more imaginary than actual. Strict adherence to the mesial position for the rest is not rational for toothsupported dentures and may be questioned for some extension-base prostheses. I-bars have several advantages as direct retainers. However, no single type of retainer is applicable for all retentive situations, and other types should be selected where conditions are unfavorable for I-bar use. A framework which permits a slight amount of movement toward the edentulous residual ridge is an important consideration in design of extension-base removable partial dentures, particularly for those of the mandibular arch. However, compromise of this principle is sometimes necessary to satisfy other design requirements. Design of the framework is only one of the factors that contribute to a successful removable partial denture. Of at least equal importance is the adequacy of support provided by the denture base and the nature of the occlusion. If meticulous attention is directed to these two factors, the forces transmitted to the teeth through the framework can be kept to a minimum and within physiologic tolerance. Conversely, neglect of these considerations may cause a framework of any design to become destructive.  相似文献   

17.
Missing anterior teeth are being replaced by implant-supported restorations quite frequently in modern dentistry. Providing the patient with a temporary prosthesis prior to or following implant fixture placement must satisfy established esthetic and functional criteria. When orthodontic treatment is included as part of the overall treatment effort, additional considerations include the retention and stabilization of newly established tooth positions. This article describes the fabrication, use and advantages of a provisional anterior prosthesis that replaces missing teeth prior to or following implant placement.  相似文献   

18.
The elderly have both the greatest level of need for prosthodontic services of any age group, and the greatest degree of complicating dental, medical, and behavioral factors. Issues arise in daily practice of whether or not to replace a missing tooth or teeth for a patient of advanced age and a wide variety of challenges-dental/oral and others-face the dentist who is considering replacing some or all of an older person's teeth. This article focuses on clinical approaches and techniques that have proven particularly important and useful for providing prosthodontic care to the older adult.  相似文献   

19.
The force distribution of multiple tooth-supported and implant-supported prostheses is completely different. A direct correlation exists between the degree of flexion at the site of loading and the amount of force distribution to other members of the prosthesis. Micromovement produced by the periodontal fibers facilitates force distribution to all the root surfaces of the natural tooth abutments. The rigidity of the implant/abutment/prosthesis configuration concentrates the force at the crestal bone at the site of loading with limited distribution to the remaining implants. Differential mobility concentrates the force distribution to the bone support of the most rigid members of splinted natural teeth or to the implants when they are united with natural teeth in a combined prosthesis. Implants always support the natural teeth and never the other way around. Therefore a nonrigid attachment is recommended between a tooth-supported prosthesis and an implant-supported prosthesis when they are combined. However, when implants are interspersed with natural teeth in the same prosthesis, the restoration will be implant borne. This requires special force distribution analysis to prevent implant overload.  相似文献   

20.
Developments in biomaterials in the field of adhesion have made possible a less invasive dentistry. Improvements in adhesive polymers along with the analysis of certain failures in resin-bonded prostheses have suggested the micropreparation of abutment teeth. A long-term study of resin-bonded prostheses and splints was undertaken. The success rate of this protocol is presented for a study period of 10 years (1984 to 1993). These results indicated that the resin-bonded prosthesis is a viable option in patients who are missing one or two teeth. Of 145 prostheses, 11 failed, resulting in an overall survival rate of 83% (Kaplan-Meier test). Furthermore, the study confirmed that, for splints, preparation is important to counter the major stresses related to tooth mobility in patients with periodontal disease.  相似文献   

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