Extensive fixed partial dentures on mandibular canine teeth: a 5-year recall study

Twelve patients were followed for 5 years after treatment with a 12-unit cantilever fixed partial denture on the mandibular canines opposed by a complete maxillary denture. Two fixed dentures had to be removed, one because of an abutment tooth root-fracture and one because of rapid marginal bone loss in a terminal stage of leukemia. Caries and periodontal lesions were rare, but other complications, principally related to endodontics, occurred. All complications were amenable to standard treatment procedures. Extensive mandibular cantilever fixed partial dentures may be used in the rehabilitation of patients with a very reduced dentition and a history of difficulties in adapting to removable dentures.     

Long-term observations of extensive fixed partial dentures on mandibular canine teeth

summary Twelve patients were followed for 15 years after treatment with a 12-unit cantilever fixed partial denture on the mandibular canines opposite to a complete maxillary denture. Four constructions failed and had to be removed but four were still in function after 15 years. Four patients died during the observation period still wearing their constructions. Endodontic complications, pulpal necrosis and loss of retention of posts were the most frequent, while caries and periodontal lesions were rare. The maintenance costs over the years were fairly low even compared to the maintenance costs for patients treated with implants. Extensive mandibular cantilever fixed partial dentures may be used in the rehabilitation of patients with a very reduced dentition and a history of difficulties in adapting to removable dentures.     

Twenty-year experience with 12-unit fixed partial dentures supported by two abutments

Eleven patients who had only two remaining natural teeth, vital mandibular canines, were treated using experimental 12-unit fixed partial dentures and complete maxillary dentures. The marginal bone support was 60% in one patient and 80% to 100% in the others. The patients were studied for 20 years. After 15 years, seven patients had prostheses that were still functional, two had prostheses that failed, one lost the prosthesis following treatment for oral cancer, and one patient died. Nine of the 22 abutments required endodontic treatment. After 15 years, the fixed partial dentures began to tilt distally and considerable resorption was found under the pontics. The periodontal tissues withstood the increased stress, and the prostheses were stable.     

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.     

A 5-year longitudinal study of cantilevered fixed partial dentures compared with removable partial dentures in a geriatric population

Prosthesis function and dental conditions were observed for 5 years in 27 elderly patients treated with mandibular cantilevered fixed partial dentures (FPDs) and in 26 elderly patients treated with distal-extension removal partial dentures (RPDs). All patients were treated with a complete upper denture. The patients were assigned randomly into two treatment groups that had the same composition with regard to sex, age, and distribution of teeth. The patients were under supervised oral hygiene and prosthodontic care. Clinical examination of prostheses, masticatory system, periodontal status, and caries was carried out yearly. Oral hygiene was good, and the periodontal status was maintained in both groups. Caries was observed six times more frequently in the RPD group than in the group with fixed restorations, however. Occlusal and functional conditions deteriorated in the RPD group only. Eight of 42 fixed partial dentures (19%) failed; of these, six were recemented with composite resin. Generally the need for dental and prosthetic follow-up treatment was more pronounced in the RPD group than in the FPD group.     

Long-term prognosis of extensive polyunit cantilevered fixed partial dentures.

The aim of this retrospective study was to elucidate the long-term prognoses of extensive fixed partial dentures including unilateral or bilateral polyunit cantilevers in patients with healthy but reduced periodontal support. Following periodontal therapy 36 cross-arch fixed partial dentures with two or more cantilever units unilaterally or bilaterally were fitted in 34 patients. In the prosthodontic design, special attention was given to the retention to long parallel preparations, to the dimensions of the framework, and to the occlusal design. After completion of therapy, the patients were enrolled in a regular maintenance care program and followed up for a period of 5 to 12 years. During this follow-up period one abutment tooth was fractured in one patient. One fixed partial denture with extremely reduced periodontal support was lost as a result of complete periodontal breakdown from occlusal trauma. For 33 fixed partial dentures, neither periodontal nor technical complications occurred.     

Occlusal force pattern during mastication in dentitions with mandibular fixed partial dentures supported on osseointegrated implants

The occlusal force pattern during chewing and biting was studied in eight edentulous patients whose dentitions had been restored with mandibular bilateral posterior two-unit cantilever fixed prostheses supported on osseointegrated titanium fixtures and occluding with complete maxillary dentures. The chewing pattern was comparable to that reported for subjects with complete healthy dentitions or with tooth-supported cross-arch fixed partial dentures. However, during chewing and swallowing the voluntary capacity of the jaw-closing muscles was used to a much greater extent. Contrary to reports for cantilevers in tooth-supported cross-arch unilateral posterior two-unit cantilever fixed partial dentures occluding with natural teeth, the posterior cantilever segments in the present fixture-supported cantilever prostheses occluding with complete dentures regularly exhibited the largest local forces. Despite this, material failures of this type of fixed prostheses are rare, as demonstrated in long-term follow-up studies.     

下颌第二磨牙缺失单端固定义齿修复的临床观察

目的：观察下颌第二磨牙缺失单端固定义齿修复的临床效果。方法：对以下颌第二前磨牙和第一磨牙为基牙，以单端固定义齿修复下颌第二磨牙缺失的25例患者进行临床和放射检查。结果：所修复的25例病例中有2例失败于固位力不足，1例失败于基牙折裂。其它均使用良好。结论：只要桥体设计合理，基牙牙体及牙周状况好，可以单端固定义齿的形式修复缺失的下颌第二磨牙。     

Retrospective evaluation of complete-arch fixed partial dentures connecting teeth and implant abutments in patients with normal and reduced periodontal support

STATEMENT OF PROBLEM: The clinical outcome of complete-arch fixed prostheses supported by implants and natural tooth abutments in patients with normal or reduced periodontal support has been reported by few studies, with controversial results. PURPOSE: The purpose of this study was to report on the implant success rate, prosthetic complications, and the occurrence of tooth intrusion, when complete-arch fixed prostheses, supported by a combination of implants and teeth, were fabricated for patients with normal and reduced periodontal support. MATERIAL AND METHODS: Nineteen patients with residual teeth that served as abutments were consecutively treated with combined tooth- and implant-supported complete-arch fixed prostheses and were retrospectively evaluated after a period varying from 24 to 94 months. Nine patients showed reduced periodontal support as a result of periodontal disease and treatment (RPS group), and 10 patients had normal periodontal support of the abutment teeth (more than 2/3 of periodontal support [NPS group]). Ninety implants and 72 tooth abutments were used to support 19 fixed partial dentures. Screw- and cement-retained metal-ceramic and metal-resin prostheses were fabricated with rigid and nonrigid connectors. Implant survival and success rates, occurrence of caries and tooth intrusion, and prosthetic complications were recorded. The number of teeth, implants, prosthetic units, fixed partial dentures, and nonrigid connectors were compared with a t test to assess differences between the 2 groups, while data for the occurrence of intrusions and prosthetic complications were compared with the Fisher exact test (alpha=.05). RESULTS: One of the 90 implants was lost (99% survival rate) over 24 to 94 months, while 3 implants showed more than 2 mm of crestal bone loss (96% success rate) over the same period. No caries were detected, but 5.6% (4/72) of the abutment teeth exhibited intrusion. Intrusion of abutment teeth was noted in 3 patients who had normal periodontal support (13% of teeth in NPS group) of the abutment teeth and was associated with nonrigid connectors. No intrusion of teeth was noted in the patients exhibiting reduced periodontal support regardless of the type of connector or when a rigid connector was used for either group. The number of intruded teeth was significantly greater in patients with intact periodontal support (P=.03). CONCLUSIONS: Complete-arch fixed prosthesis supported by implant and tooth abutments may be associated with intrusion of teeth with intact periodontal support when nonrigid connectors are used to join the implant- and tooth-supported sections of the prostheses. However, fixed partial dentures supported by implants and teeth with reduced periodontal support were not associated with tooth intrusion, regardless of the type of connectors used.     

Clinical examination and interleukin-1beta levels in gingival crevicular fluid in patients treated with removable partial dentures

PURPOSE: The purposes of this study were to investigate the periodontal status and susceptibility to periodontal disease progression of the teeth in contact with removable partial dentures (RPD) and to compare them with control teeth in mouths not restored with a partial denture, by means of both clinical parameters and interleukin (IL)-1beta levels in gingival crevicular fluid. MATERIALS AND METHODS: Twenty-eight periodontally healthy patients were selected for the study; 14 of them were treated with mandibular Kennedy Class I RPDs, and the other 14 patients were not restored for control. Clinical periodontal measurements were assessed, and crevicular fluid samples were collected from both abutment and control teeth to determine IL-1beta levels, which were measured by enzyme-linked immunosorbent assay. These procedures were performed both at baseline and 9 months after the insertion of the dentures. RESULTS: The wearing of RPDs resulted in statistically higher clinical scores and total IL-1beta levels compared to the baseline examination. In contrast, no statistically significant differences were found between baseline and 9-month examinations in the control group. CONCLUSION: RPDs are a risk factor for periodontal disease progression because of increased plaque accumulation associated with increased total IL-1beta levels and impaired clinical periodontal parameters.     

Occlusal force pattern in dentitions with mandibular implant-supported fixed cantilever prostheses occluded with complete dentures

Naturally occurring axially directed closing and chewing forces were measured in ten patients with mandibular fixture-supported cross-arch prostheses occluding with maxillary complete dentures. The design of the mandibular constructions was characterized by bilateral posterior two-unit cantilevers. The forces were measured using eight miniature strain gauge transducers mounted in the maxillary denture and evenly distributed over the tooth arch. Forces were thus measured at four occlusal contact points over the fixture segment and over each of the four posterior cantilever units simultaneously, giving a detailed picture of the force distribution. The total forces developed during maximal closing in habitual occlusion and chewing were of the same magnitude as previously reported for patients with tooth-supported cross-arch fixed partial dentures occluding with natural teeth using the same method. Contradictory to previous findings, in dentitions with comparable tooth-supported cantilever constructions occluding with natural teeth, local closing and chewing forces increased bilaterally in the distal direction. On average, 70% of the forces were borne by the cantilevers and 30% by the fixture-supported segment of the prostheses.     

Technical failures and some related clinical complications in extensive fixed prosthodontics. An epidemiological study of long-term clinical quality

Three hundred and sixteen fixed partial dentures made in 1975-1976 by 112 general practitioners in Malm?, Sweden, were selected for a questionnaire study of the technical failure rates after 6-7 years. Cariologic, periodontal, endodontic, and esthetic complications were also identified, as were those appearing in the stomatognathic system. The total material consisted of three groups with an approximately equal number of reconstructions. One group consisted of fixed partial dentures with distal abutment teeth, another was formed of fixed prostheses with single cantilever pontic/pontics, and a third consisted of double cantilever pontics. Excluding the 26 reconstructions, which had been made for patients who died (24) or emigrated (2) during the observation period, data was obtained for 97% of the selected restorations. The results showed high rates of cariologic (18-31%), endodontic (5-23%), periodontal (7-12%), esthetic (10-16%), and technical (8-34%) complications. Differences were noted between the groups. For all types of technical failures (fractures and loss of retention) higher frequencies were related to the extent of cantilevering. Direct relationships were found between the technical failure rate and the time in service, the sum of all cantilever extension pontics in the reconstructions, and the state of the pulps of the distal abutments. No relationship was found between the technical failure rate and the status of the dentition in the opposing jaw. The clinical significance of the results obtained is discussed.     

Fixed cantilever splints on teeth with normal and reduced periodontal support

Photoelastic models were used to visualize stresses developed in teeth and supporting bone by cantilever fixed partial dentures where the most distal abutments had either crater or trough osseous defects. The effects of splinting the periodontally involved teeth to one or more additional sound teeth were studied. It was shown that for a cantilever fixed partial denture with either normal periodontal support, or a distal abutment with a moderate degree of mobility and bone loss, the following can be concluded: (1) occlusal forces on a cantilever fixed partial denture were significantly distributed to only the three teeth closest to the loaded cantilever, (2) optimum stress reduction occurred with the splinting of a periodontally compromised tooth to two periodontally sound teeth. Increasing the number of splinted abutments did not result in a proportional reduction of stress in the periodontium, and (3) no significant cross-arch sharing of occlusal loads was seen.     

Cantilever bridges or removable partial dentures in geriatric patients: a two-year study

The purpose of this study was to compare prosthetic, functional and occlusal conditions in twenty-seven patients treated with distally extending cantilever bridges and twenty-six patients treated with removable partial dentures (RPD) in the mandible. All patients had a complete upper denture. Mean age of the patients in both groups was about 69 years. The patients were under a supervised oral hygiene care throughout the 2-year study period. There were 6.9 +/- 1.7 mandibular teeth left in the bridge group and 7.5 +/- 1.7 in the RPD group and the mean number of posterior teeth (natural teeth/denture teeth/pontics) in occlusion was 4.1 +/- 1.1 and 7.3 +/- 1.4, respectively. During the study period signs and symptoms of mandibular dysfunction became significantly aggravated in the RPD group, P less than 0.05. A balanced occlusion in the muscular contact position was observed in 90% of the patients in the bridge group and in 76% of the RPD wearers. During the study period the need for dental or prosthetic treatment was negligible in the patients treated with bridges. In the RPD group, twenty-two teeth were restored with fillings due to caries and in eight patients major adjustments of the sublingual bar were necessary due to irritation of the oral mucosa. This study has shown that treatment with distally extending cantilever bridges in the mandible is a favourable alternative to treatment with removable partial dentures in elderly patients with a reduced dentition.     

Patient satisfaction following restoration of shortened mandibular dental arches in a randomized controlled trial

PURPOSE: Removable partial dentures (RPD) used to restore the severely shortened mandible may adversely affect the remaining natural teeth and are associated with a low prevalence of use. This pilot study investigated patient satisfaction following restoration of mandibular shortened dental arches. MATERIALS AND METHODS: Sixty subjects with mandibular shortened dental arches entered a randomized controlled trial comparing two types of mandibular prostheses: bilateral free-end saddle RPDs and distal cantilever resin-bonded fixed partial dentures (FPD). Patient satisfaction was assessed using self-administered questionnaires before (baseline), 3 months after, and 1 year after provision of new prostheses. RESULTS: Improvements in levels of general satisfaction with teeth, appearance of teeth, and perceived masticatory ability were significant for the FPD group. Significant improvements in perceived masticatory ability were noted for both groups. There were also significant improvements in perceived levels of comfort of mandibular prostheses in both groups. Changes in summary satisfaction scores indicated improved satisfaction for both treatment groups but suggested a larger clinical effect for the FPD group. Significant differences between treatment groups were not established. CONCLUSION: Patient-based outcomes reported suggested that resin-bonded cantilever FPDs are an effective means of restoring the shortened mandibular dental arch in terms of patient comfort and acceptance.     

A retrospective analysis of factors associated with the periapical status of restored,endodontically treated teeth

PURPOSE: The purpose of this study was to explore possible associations between prosthodontic, occlusal, endodontic, and periodontal factors and the endodontic status of endodontically treated teeth. MATERIALS AND METHODS: Forty-six patients who had received endodontic treatment followed by a fixed restoration for at least one of their teeth were recalled and examined clinically and radiographically according to a predetermined set of evaluation criteria. A total of 89 teeth were included, and data obtained included assessments of the coronal restoration and post and core, occlusal contact relationships, a number of endodontic parameters, and periodontal status of the study teeth. For the latter assessment, 54 contralateral teeth were available for purposes of comparison. Teeth were grouped into those with and without periapical radiolucencies, and differences between the groups, with respect to all parameters, were analyzed by logistic regression. RESULTS: Three factors were significantly associated with the presence of radiolucency: confirmed occlusal contact, by virtue of the tooth being either involved in group function or the only contact in working-side and protrusive movements, and endodontic filling and crown margins of poor quality. None of the other independent variables showed significant associations with the dependent variable of periapical radiographic appearance. Contralateral teeth had better periodontal conditions than restored study teeth. CONCLUSION: The finding that a good-quality endodontic filling and crown margin improve endodontic outcome corroborates many other similar reports; however, with occlusal contact shown to be associated with failing endodontic treatment, the range of factors that may influence endodontic outcome appears to have widened.     

Periodontal conditions following treatment with distally extending cantilever bridges or removable partial dentures in elderly patients. A 5-year study

The aim of the present study was to evaluate the periodontal conditions following treatment with distally extending cantilever bridges or removable partial dentures (RPDs) in elderly patients. All participants had a complete denture in the maxilla and moderate-to-advanced bone loss around the teeth present in the mandible. After undergoing periodontal treatment, 27 patients were treated with distally extending cantilever bridges and 25 patients with a RPD. During the first 2 years following prosthetic treatment, the patients were recalled twice a year and during the last 3 years once a year for oral prophylaxis and assessment of the periodontal status. The patients treated with a RPD showed higher mean Plaque and Gingival Indexes than the patients treated with cantilever bridges. No change in probing pocket depths was observed in either group, and only a small decrease in radiographic alveolar bone height was revealed. In conclusion, only minor changes in the periodontal conditions were recorded during the 5 years of observation after treatment with cantilever bridges or RPDs.     

Intrusion Of Teeth In The Combination Implant-to-Natural-Tooth Fixed Partial Denture: A Review of the Theories

This article reviews the literature dealing with the combination implant-to-natural-tooth-supported fixed partial denture. The restoration of masticatory function with a combination implant-to-natural-tooth fixed partial denture is associated with a variety of undesirable clinical sequelae, including the breakage of implant components, damage to the abutment teeth, or intrusion of the abutment teeth. Theories regarding intrusion of abutment teeth combined with implants for fixed partial dentures are only speculative. Several theories are presented to explain the intrusion of natural teeth in association with implant-to-natural-tooth fixed partial dentures. One of the first theories was based on the idea that a lack of normal stimulation of the periodontal ligament produces atrophy of the periodontal ligament and intrusion of the tooth. The remaining theories relate to excessive forces being placed on the natural tooth, resulting in movement of the tooth to a less stressful position. These forces are placed on the tooth by differential energy dissipation, mandibular flexion and torsion, flexion of the fixed partial denture framework, impaired rebound memory, debris impaction or microjamming, or ratchet effect related to the use of precision attachments. Based a review of the literature, a philosophy for treating combination implant-to-natural-tooth restorations is presented.     

Fixed partial dentures supported by periodontally compromised teeth

This study tested the effect of fixed partial dentures on hypermobile abutment teeth with substantially reduced levels of periodontal attachment. One abutment tooth and one control (nonabutment) tooth of the same type and periodontal condition were selected for study in adults. Treatment consisted of periodontal therapy and a 3- or 4-unit fixed partial denture, after which all subjects were placed on a quarterly maintenance schedule. No differences were found between the mean baseline and 24-month measures for all dependent variables at test or control sites.     

Functional analysis of fixed bridges on abutment teeth with reduced periodontal support

The present study examines (he function of fixed bridges on abutment teeth with reduced but non-inflamed periodontal tissues. Eighteen patients with advanced periodontal breakdown and indication for oral rehabilitation received periodontal treatment and their dentitions were restored with fixed bridgework. The analysis of function performed 2-5 years after insertion of the reconstructions was made by (1) evaluation of the patients' opinion on chewing ability and function of the masticatory system; (2) clinical examination of the border movements of the mandible, the status of the temporomandivular joints and the chewing muscles, and (3) measurements of the bite force in different areas of the dentition. The results of the study show that the functional capacity of the type of extensive bridgework discussed is good and that the patients–in spite of severe loss of periodontal tissue–achieve bite force values that are almost comparable to those in individuals with natural teeth. Comparison of the function of fixed bridges and that of removable dentures is also discussed.