***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: A r and omized clinical trial was undertaken to compare the effectiveness of two partial denture design s , one with I-bar ( bar ) and the other with circumferential retainers ( circumferential ) , in 134 patients with Kennedy class I and class II edentulous conditions . A total of 30 partial dentures were considered failures , five because of abutment failures and 25 because of the lack of removable partial denture use for eating . The 5-year success rate of 71.3 % for the circumferential design did not differ significantly from the 76.6 % for the bar design ( p > 0.05 ) . There were no discernible changes in the nine periodontal health components of abutment teeth with either of the two design s after 60 months . The results indicate that the two design s do not differ significantly in terms of success rates , maintenance care , and effects on abutment teeth . A well-constructed removable partial denture of either design , supported by favorable abutments and accompanied by a regular recall program offers a satisfactory treatment modality Objectives The study was design ed to provide clinical outcome data for two treatments of the shortened dental arch ( SDA ) . Material and Methods In a multicenter r and omized controlled clinical trial , patients with complete molar loss in one jaw were provided with either a partial removable dental prosthesis ( PRDP ) retained with precision attachments or treated according to the SDA concept preserving or restoring a premolar occlusion . No implants were placed . The primary outcome was tooth loss . Results Of 152 treated patients , 132 patients reached the 5-year examination . Over 5 years , 38 patients experienced tooth loss . For the primary outcome tooth loss , the Kaplan – Meier survival rates at 5 years were 0.74 ( 95 % CI 0.64 , 0.84 ) in the PRDP group and 0.74 ( 95 % CI 0.63 , 0.85 ) in the SDA group . For tooth loss in the study jaw , the survival rates at 5 years were 0.88 ( 95 % CI 0.80 , 0.95 ) in the PRDP group and 0.84 ( 95 % CI 0.74 , 0.93 ) in the SDA group . The differences were not significant . No Cox regression models of appropriate fit explaining tooth loss on the patient level could be found . Conclusions The overall treatment goals of a sustainable oral rehabilitation and the avoidance of further tooth loss over longer periods were not reliably achievable . The influence of the type of prosthetic treatment on tooth loss might have been overestimated . Clinical Relevance Regarding our results , the patient ’s view will gain even more importance in the clinical decision between removable and fixed restorations in SDAs Removable partial dentures may adversely affect remaining tissues and have a low prevalence of use . This r and omized controlled trial was design ed 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 r and omly 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 STATEMENT OF PROBLEM It is important to evaluate the long-term clinical performance of resin-bonded fixed partial dentures and extracoronal attachments for removable prostheses . PURPOSE A prospect i ve , long-term clinical study was conducted to evaluate the success of resin-bonded fixed partial dentures since 1985 and of resin-bonded extracoronal attachments from 1987 . METHODS Until 1993 , a total of 130 resin-bonded fixed partial dentures had been seated in 101 patients , as well as 12 removable partial dentures ( RPDs ) with 24 extracoronal retainers in 10 patients . The clinical treatment protocol and the laboratory procedures were st and ardized . By the end of 1993 , it was possible to reexamine 98 patients with a total of 127 resin-bonded fixed partial dentures and all 10 patients with removable partial dentures . The average time in function for the resin-bonded fixed partial dentures at the time of examination was 3.4 years and 2.3 years for the removable restorations . RESULTS During the period of observation , one retainer failed on six of the resin-bonded fixed partial dentures , which represents a failure rate of 4.7 % . Debonding of extracoronal attachments was recorded for 8.3 % of the total number of retainers . CONCLUSION The resin-bonded fixed partial denture technique can be considered to be a clinical ly reliable method of treatment , and permits the expansion of indications beyond a classical three-unit resin-bonded fixed partial denture . Long-term clinical success of removable partial dentures with resin-bonded extracoronal retainers warrants additional clinical studies 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 m and ibular 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 clinical ly significant . Excluding the 10 early failures , the 5-year  FPD success rate was 91.5 % . Of the 170 attempted implants , 26 failed , including 12 before the FPD fabrication . Radiographic assessment s 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 CONTEXT Removable partial dentures used to restore the shortened lower dental arch may adversely affect the remaining natural teeth and are associated with a low prevalence of use . OBJECTIVE To report the findings for caries incidence 2 years after restoration of lower shortened arches with bilateral cantilever resin-bonded bridges ( RBBs ) and conventional partial dentures ( RPDs ) . DESIGN R and omised controlled trial . SETTING Secondary care PATIENTS 25 male and 35 female subjects of median age 67 years . were r and omly allocated to ' bridge ' and ' denture ' treatment groups of 30 patients each matched for age and sex . Caries incidence was recorded during dental examinations 3 months , 1 and 2 years after insertion of new lower prostheses . INTERVENTIONS Cantilever RBBs and conventional RPDs with cast metal frameworks . RESULTS There was a highly significant difference in the frequency of new caries lesions , 11 and 51 in the bridge and denture groups respectively ( P < 0.01 ) . 20 out of 27 bridge patients and 9 of 23 denture patients had no caries experience . Multivariate modeling identified treatment group as the only significant predictor of caries occurrence . CONCLUSIONS Two years after restoration of lower shortened arches for an elderly sample of patients , there was a significantly greater incidence of new and recurrent caries lesions in subjects restored with RPDs compared with cantilever RBBs This study examined the success of titanium ( Ti ) removable partial dentures ( RPDs )  compared with that of cobalt-chromium ( Co-Cr ) RPDs using a r and omized controlled clinical trial . Thirty-eight RPD patients were provided with either Co-Cr ( 20 patients ) or Ti ( 18 patients ) RPDs . The total numbers of dentures was 31 ( 13 maxillary , 18 m and ibular ) for Co-Cr and 23 ( 11 maxillary , 12 m and ibular ) for  Ti .  Patients were review ed for 24 months following denture issue . After the initial 12 months , 20 clinical problems were recorded and became the criteria for subsequent assessment . Incidence of failure was analysed using both Fisher 's exact test and the chi square test at a significance level of P<0.05 . Fracture of retainers in both metals occurred only in the first 12 months . Some failure types presented at significantly higher levels in the first 12 months but there were no significant differences between the two in all the criteria examined between the 12- and the 24-month review s. Although differences existed in failure types between Co-Cr and Ti RPDs during the early review stages , the overall success rate of Ti RPDs was comparable with that of Co-Cr RPDs after 24 months . The higher incidence of failures in Ti RPDs prior to the 12-month review suggests the importance of taking its lower rigidity into account when design ing RPDs PURPOSE The aim of this study was to quantify and compare the clinical performance of cast conical double crown-retained removable partial dentures ( C-RPDs )  and electroplated double crown-retained removable partial dentures ( EP-RPDs ) . MATERIAL S AND METHODS A total of 60 RPDs were placed in 54 patients . Participants were r and omly assigned to two study groups ( C-RPD and EP-RPD ) . Altogether , 217 abutment teeth were provided with double crowns .  Patients were reexamined after 6 , 12 , 24 , and 36 months . The main endpoints were the survival times of RPDs and abutment teeth ; secondary endpoints included failure of the facing , loss of cementation of primary crowns , and postprosthetic endodontic treatment . Chi-square tests were used to evaluate group differences regarding characteristics of patients and RPDs . Survival differences were investigated using the log-rank test and Cox regression ; secondary endpoints were assessed using logistic regression . RESULTS After 36 months , survival was 100 % for C-RPDs and 93.3 % for EP-RPDs .  Cumulative survival for abutment teeth was 97.3 % ( C-RPDs ) and 96.2 % ( EP-RPDs ) . Survival differences between the two study groups did not reach statistical significance . The survival of abutments depended on tooth vitality and position ; for example , the hazard of tooth loss was 676 % higher for nonvital teeth . No differences were found between study groups regarding facing failure , decementation of primary crowns , or postprosthetic endodontic treatment . CONCLUSIONS Vitality and position are important to the survival of teeth supporting partial dentures . Longer follow-up and larger patient collectives are needed to evaluate possible differences between cast conical and electroplated telescopic double crown-retained partial dentures Prosthesis function and dental conditions were observed for 5 years in 27 elderly patients treated with m and ibular 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 r and omly 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 
    Output:
    
The better the pre-treatment and supportive care is , the smaller the differences are .
The results for the parameters probing depth and radiological bone loss were inconclusive .
Gingival recessionGingival recession seemed to be favored by a m and ibular sublingual bar .
Compared to fixed restorations , removable restorations seemed to be associated with a more pronounced need for dental treatment .
Stringent pre-treatment and supportive care reduced the complication rates .
Clinical relevance Within the limitations of this study , it would be correct to state that removable dental prostheses require intensive maintenance .
Suitable pre-treatment and supportive care can lower the complication rates , in the absence of which they constitute trigger factors for ( additional ) biological complications