Veterans Administration Cooperative Dental Implant Study--comparisons between fixed partial dentures supported by blade-vent implants and removable partial dentures. Part III: Comparisons of masticatory scores between two treatment modalities

Five Veterans Administration Medical Centers participated in a study to determine the comparative influence of fixed partial dentures (FDPs) supported by endosteal blade implants and removable partial dentures (RPDs) on masticatory performance. The study design, methodology, and success rates have been described in Parts I and II. A total of 232 patients received comprehensive dental care, including RPDs for 118 patients and FPDs for 114. Three standardized masticatory tests were made with peanuts and carrots before treatment. These tests were repeated at 16 weeks following RPD or implant insertion and thereafter at 6, 18, 36, and 60 months. At entry, there were no significant differences in performance scores and chewing time and strokes taken to reach the swallowing threshold between the RPD and FPD groups (p greater than 0.05). After treatment completion, FPDs and RPDs significantly improved the masticatory ability of patients with Kennedy class I or class II edentulous conditions (p less than 0.001). The improvements in performance scores for both test foods were slightly better in the RPD group than in the FPD group, although none of the 30 mean differences was significant (p greater than 0.05). After the baseline period to 60 months, only slight changes in performance scores were observed for both groups. RPDs and FPDs were comparable in improving the chewing efficiency of patients with Kennedy class I and class II partially edentulous conditions.     

Veterans Administration Cooperative Dental Implant Study--comparisons between fixed partial dentures supported by blade-vent implants and removable partial dentures. Part IV: Comparisons of patient satisfaction between two treatment modalities.

This study compares treatment assessments made by two groups of patients with Kennedy class I or class II mandibular edentulous conditions, who received either a removable partial denture (RPD) (N = 115) or one or two fixed partial dentures (FPDs), each supported distally by a blade implant (N = 113). Two questionnaires were administered, one at 16 weeks after the implant or RPD insertion and at the 6-month interval and the other at 18, 36, and 60 months. Marked functional improvements were perceived by a large majority of patients in both groups after the insertion of prosthesis. At 6 months, a higher percent of patients with RPDs than those with FPDs found it easy to clean their RPDs and experienced chewing discomfort, restriction of food choices, feeling of insecurity with their RPDs, and difficulty with their pronunciation. The exclusion of assessments by 25 RPD patients, whose treatment was judged to be a failure functionally, made the mean differences between the two treatments statistically significant (p less than 0.05) only for ease of cleaning in favor of the RPD and fewer restrictions of food choices in favor of the FPD group. At 60 months, significant differences between the percents of patients with the most favorable responses occurred for perceptions of eating enjoyment, food particles seldom getting under the removable partial denture, and improvement in social life in favor of the FPD treatment and for the ease of cleaning the removable partial denture in favor of the RPD treatment. The results seem to support superiority of the FPD in terms of patient satisfaction, but not enough to favor this type of prosthesis over the RPD without consideration of other pertinent factors.     

Veterans administration cooperative dental impant study—Comparisons between fixed partial dentures supported by blade-vent implants and removable partial dentures. Part II: Comparison of success rates and periodontal health between two treatment modalities

Five Veterans Administration centers have participated in a study to determine whether fixed partial dentures (FPDs) supported by blade implants offer an acceptable substitute for mandibular unilateral or bilateral distal-base extension removable partial dentures (RPDs). The study design and methodology have been described in Part I. A total of 232 patients received comprehensive dental care including RPDs for 118 patients and FPDs for 114. Prespecified criteria determined treatment failures. During the 60-month period, treatment failures occurred in 19 FPD patients and 30 RPD patients. Ten FPD failures occurred before and nine after the FPD insertion. Five RPD failures were caused by abutment tooth loss and 25 for not using the RPD while eating. Life table analysis showed 5-year success rates of 84.2% for the FPD and 74% for the RPD. The 17.9% higher FPD success rate in Kennedy class II patients was both statistically and clinically significant. Excluding the 10 early failures, the 5-year FPD success rate war 91.5%. Of the 170 attempted implants, 26 failed, including 12 before the FPD fabrication. Radiographic assessments by a panel of three judges showed no bone deterioration during baseline to 60 months in 29.6%, slight in 25.4%, moderate in 15.9>, marked in 27%, and severe deterioration in 2.1% of the implant posts.     

Comparisons of tactile thresholds between implant-supported fixed partial dentures and removable partial dentures.

This study compared the tactile sensitivity of splinted abutment and denture teeth of 16 fixed partial dentures (FPD) supported by blade implants and 16 removable partial dentures (RPD) in patients with Kennedy Class I and Class II edentulous conditions. No significant differences were noted between the tactile thresholds of the natural abutment teeth and artificial teeth in the FPD and RPD groups. The splinted abutment teeth required 45.4 g, or 5.4 to 5.8 times higher occlusal loads than did those needed for the comparable nonsplinted teeth, to detect the stimulus. A further increase of 54% in thresholds with the FPD and over 100% with the placement of the RPD indicated the superiority of the RPD in terms of load distribution as a result of the cross-arch splinting and mucosal support. Moderate positive correlations (r = 0.37 to 0.46; P < .05) between tactile thresholds and masticatory performance were found, signifying that reduced tactile perception was not responsible for the incomplete restoration of the masticatory function with RPDs or FPDs but might be contributing to increased masticatory performance within both treatment groups.     

Prosthodontic decision making among general dentists in Sweden. II: The choice between fixed and removable partial dentures

PURPOSE: The purpose of this study was to describe how dentists evaluated various items related to a treatment choice between fixed partial dentures (FPD) and removable partial dentures (RPD), and to determine if the differences could be explained by dentist-related variables ("social and demographic attributes," "job situation," and "attitudes"). MATERIALS AND METHODS: Questionnaires were sent to a random sample of 2,059 Swedish general dentists, with a response rate of 76%. In the questionnaire, the choice between FPDs and RPDs in a clinical situation was presented. The dentists were asked to mark on 14-item visual analogue scales the relative importance he or she gave the different items. The items were analyzed through principal components analysis, where a 3-factor solution was obtained; the factors were labeled as "time," "health," and "comfort." The factors were run as dependent variables in multiple regression analyses. RESULTS: Great individual variations were seen, but the differences between groups of dentists were small. The items evaluated as most important were "patient's wish," "condition of possible abutment teeth," and "prognosis for delivered treatment." Male dentists gave significantly greater importance to the "health" factor compared to female dentists. The attitudinal variable "patient information" showed significant associations with all 3 factors in the multivariate models. CONCLUSION: Great individual differences were seen regarding the importance of the various items. In multiple regression models, several independent variables showed significant associations, most interestingly the attitudinal variable "patient information." Low explanatory (R2) values indicate that it is necessary to capture more variables of importance for the prosthodontic decision-making process.     

Comparative evaluation of chewing function with removable partial dentures and fixed prostheses supported by the single-crystal sapphire implant in the Kennedy Class II partially edentulous mandible

Differential chewing function with removable partial dentures (RPDs) and fixed prostheses supported by the single-crystal sapphire implant was evaluated in five subjects with Kennedy Class II partially edentulous mandibles by means of electromyography. Rehabilitation with the single-crystal sapphire implant resulted in regular chewing patterns with a low variation coefficient and higher activity of chewing-side masticatory muscles compared to RPD rehabilitation. This difference in chewing function between the two rehabilitation modalities could be the result of differences in stability of occlusion and neurophysiologic feedback systems.     

Effects of rehabilitation with conventional removable partial dentures on oral health--a cross-sectional study. Part II. A comparative study of treatment results at two Public Dental Clinics and the Faculty of Odontology in Gothenburg

Sixty-five patients from two counties, rehabilitated with conventional partial dentures, participated in a clinical study of oral and denture hygiene, periodontal health, incidence of caries, denture retention and frequency of use. The clinical study was supplemented with an anonymous questionnaire. The aim of the study was to describe the consequences of the treatment with respect to the oral tissues and to compare the findings with those in a corresponding study of patients treated at the Faculty of Odontology in Gothenburg. The results show deficiencies in periodontal and cariological pretreatment and follow-up. The subjective results of the prosthodontic treatment seem, however, to be satisfactory, as was the frequency of use of the dentures (92 per cent). The study shows a need to improve the quality of dental care for adults. The current decline in demand for dental care for children should release resources for treatment of adults in the Public Dental Service.     

A 2‐year report on maxillary and mandibular fixed partial dentures supported by Astra Tech dental implants. A comparison of 2 implants with different surface textures.

In 50 partially edentulous patients, 133 (48 maxillary; 85 mandibular) Astra Tech dental implants of 2 different surface textures (machined; TiO‐blasted) were alternately installed, supporting 52 fixed partial dentures (FPDs). Before abutment connection 2 machined implants (1 mandibular; 1 maxillary) were found to be non-osseointegrated and were replaced. Another implant could not be restored due to a technical complication. Two FPDs were remade because of technical complications, both because of abutment fractures. Thus, after 2 years in function, the cumulative survival rates were 97.7% and 95.7% for implants and prostheses, respectively. There was no statistically significant difference in survival rate between the 2 types of implants, 100%(TiO‐blasted) vs 95.3%(machined), P =0.24. After 2 years in function, when both jaw and type of implants were combined, the mean (SD) marginal bone loss was 0.24 (0.69) mm. No statistically significant difference in bone loss was found between the 2 tvues of implant after 2 years of loading, 0.04 (0.82) mm, P >0.30.     

Implant treatment with fixed prostheses in the edentulous maxilla. Part 1: implants and biologic response in two patient cohorts restored between 1986 and 1987 and 15 years later

Purpose: Implant treatment has been performed for more than 45 years, but there is still limited knowledge on how treatment outcomes are changing over time. The aim of this study was to report and compare the treatment outcomes of two patient cohorts from the same clinic, rehabilitated with fixed implant prostheses in the edentulous maxilla between 1986 and 1987 (early) and 2001 to 2004 (late). Materials and Methods: The early group included 76 edentulous patients who were consecutively provided with 450 turned Branemark System implants; the late group included 109 edentulous patients provided with 360 turned and 310 TiUnite Branemark System implants. Both groups were followed and evaluated clinically and radiographically for 5 years according to similar protocols. Results: Altogether, 37 patients (20%) were lost to follow-up over 5 years; more patients were noncompliant in the late group (P < .05). The 5-year overall implant cumulative survival rates were 93.4% and 97.3% for the early and late groups, respectively. In the early group, significantly more turned implants failed before prosthesis insertion compared to the outcome of TiUnite implants in the late group (P < .05). Mean bone loss was comparable for the early and late groups during the 5 years of follow-up (0.5 ± 0.46 and 0.7 ± 0.76 mm, respectively), but more patients presented at least 1 implant with more than 2 mm of bone loss during the follow-up period in the late group (P < .05). Mucosal hyperplasia and inflammation showed a trend of higher frequency at implants in the early group of patients (P > .05). Conclusion: Implant treatment was more predictable before loading in the late group of patients, related to the change in the implant surface (P < .05). On the other hand, it was observed that the prevalence of patients with more bone loss at at least 1 implant (> 2 mm) was higher in the late group (P < .05). This could possibly be attributed to a more bioactive implant surface and shorter healing period before implant surgery in the late group. Int J Prosthodont 2011;24:345-355.     

Implant treatment with fixed prostheses in the edentulous maxilla. Part 2: prosthetic technique and clinical maintenance in two patient cohorts restored between 1986 and 1987 and 15 years later

Purpose: Implant treatment using osseointegrated implants has been performed for more than 40 years, but limited knowledge is available on how treatment outcomes have changed over time. The aim of this study was to report and compare the prosthetic treatment outcomes from two patient cohorts provided with fixed implant prostheses in the edentulous maxilla between 1986 and 1987 (early) and 2001 to 2004 (late) at the same clinic. Materials and Methods: The two groups of patients comprised 76 and 109 edentulous patients consecutively provided with 450 and 670 Branemark System implants and fixed screw-retained prostheses, respectively. Both groups were followed for 5 years with regard to prosthetic treatment, clinical maintenance, and complications. Results: Altogether, 37 patients (20%) were lost to follow-up during the 5 years, and more patients were noncompliant in the late group (P < .05). Prosthetic treatment was performed using significantly less chair time in the late group (P < .05), and 22 and 68 patients were followed for 5 years without any reported complications in the early and late groups, respectively (P < .05). The 5-year prosthesis cumulative survival rate was 97.1% in the early group and 100.0% in the late group. Patients in the late group presented fewer problems with diction and veneer fractures, and fewer patients had their prostheses temporarily removed for adjustments (P < .05). Conclusion: Prosthetic treatment and maintenance of implant-supported fixed prostheses improved significantly between the groups. Int J Prosthodont 2011;24:356-362.