***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Objective To analyse the factors affecting the clinical performance and those influencing the survival of  resin-retained bridgework provided at a UK dental teaching hospital between 1994 and 2001 . Design A prospect i ve analysis of restorations provided at a single centre using case notes with all patients invited for review to corroborate findings . Setting Department of Restorative Dentistry , University of Bristol Dental Hospital and School , Bristol , United Kingdom . Subjects and methods Between January 1994 and December 2001 , data regarding 1,000 consecutive resin-retained bridges provided at Bristol Dental Hospital and School were recorded . Data was available for 805 patients at the time of the study . Following invitation , 621 patients attended for a review appointment . Life table and Kaplan-Meir survival analysis were carried out for all restorations provided . Results The five-year and ten-year survival rates estimated by the life-table method are 80.8 % ( 95 % confidence interval 78.0–83.6 % ) and 80.4 % ( 95 % confidence interval 77.6–83.2 % ) respectively . The median survival can not be estimated for this study as the survival probability remains above 80 % even at the longest follow-up . Analysis of clinical variables influencing survival revealed that design of the restoration and experience of the operator providing the restoration were significant factors . Resin-retained bridges made with minimal tooth preparation are shown to be superior in terms of longevity than those for which other types of tooth preparation is made . Patient satisfaction with their treatment was high The etched-cast restoration was introduced in 1980 , and a prospect i ve study was initiated in March 1981 to determine if resin-bonded prostheses would prove to be a long-term alternative to traditional complete and partial coverage restorations . All resin-bonded restorations placed since that time in the author 's private prosthodontic practice have been recorded in the study . The success rate of 127 restorations has been 92.9 % , with a mean longevity of 5 years and 8 months PURPOSE The aim of this prospect i ve clinical evaluation was to show the long-term clinical behavior of  resin-bonded fixed partial dentures ( RBFPD )  with a retentive , minimally invasive preparation design . MATERIAL S AND METHODS Since 1985 , 232 RBFPDs with a retentive preparation design were placed under controlled clinical conditions . In 2005 and 2006 , 84 fixed partial dentures could be re-evaluated . Using Kaplan-Meier analysis , the survival rate was determined . The probability of survival was calculated with several risk factors : location ( anterior/posterior , maxilla/m and ible ) , metal alloy of the framework ( titanium/CoCr ) , number of pontics , and number of supporting teeth . RESULTS A total of 12 failures was observed and result ed in a survival rate of 77 % after 10 years . However , only 4 catastrophic failures occurred . In such cases , the restoration was lost , or could not be re-bonded or repaired ( survival rate 88 % after 10 years ) . RBFPDs made of a titanium alloy exhibited a statistically significantly higher survival rate than RBFPDs made of a nonprecious CoCr alloy in terms of all failures . Only slight but not statistically significant differences between the covariates maxilla , m and ible , anterior/posterior region , number of pontics , and number of abutment teeth were observed . CONCLUSION Within the limitations of this study , RBFPDs seem to be a reliable restorative alternative to conventional short-span fixed dental prostheses OBJECTIVES The purpose of this clinical study was to evaluate the long-term outcome of  3-unit anterior fixed partial dentures ( FPDs ) made of fiber-reinforced resin composite ( FRC )  , and to identify design factors influencing the survival rate . METHODS 52 patients ( 26 females , 26 males ) received 60 indirectly made FRC FPDs  , using pre-impregnated unidirectional glass fibers , requiring manual wetting , as framework material . FPDs were surface ( n=48 ) or hybrid ( n=12 ) retained and mainly located in the upper jaw . Hybrid FPDs had a combination of retainers ; i.e. crown at one and surface retention at the other abutment tooth . Surface FPDs were either purely adhesively retained ( n=29 ) or with additional mechanical retention ( n=19 ) . Follow-up period was at minimum 5 years , with check-ups every 1 - 2 years . Six operators were involved , in three centers in the Netherl and s , Finl and and Sweden . Survival rates , including repairable defects of FPDs , and success rates were determined . RESULTS Kaplan-Meier survival rate at 5 years was 64 % ( SE 7 % ) . For the level of success , values were 45 % ( SE 7 % ) and the estimated median survival time 58 ( SE 10.1 ) months . For surface FPDs , additional mechanical retention did not improve survival significantly . There was a trend towards better survival of surface FPDs over hybrid FPDs , but differences were not significant . Main failure modes were fracture of the FPD and delamination of veneering composite . SIGNIFICANCE A success rate of 45 % and a survival rate of 64 % after 5 years was found . Fracture of the framework and delamination are the most prevalent failure modes , especially for surface FPDs OBJECTIVE Our purpose was to measure the agreement , reliability , construct validity , and feasibility of a measurement tool to assess  systematic review s ( AMSTAR ) . STUDY DESIGN AND SETTING We r and omly selected 30 systematic review s from a data base . Each was assessed by two review ers using : ( 1 ) the enhanced quality assessment question naire ( Overview of Quality Assessment Question naire [ OQAQ ] ) ; ( 2 ) Sacks ' instrument ; and ( 3 ) our newly developed measurement tool ( AMSTAR ) . We report on reliability ( interobserver kappas of the 11 AMSTAR items ) , intraclass correlation coefficients ( ICCs ) of the sum scores , construct validity ( ICCs of the sum scores of AMSTAR compared with those of other instruments ) , and completion times . RESULTS The interrater agreement of the individual items of AMSTAR was substantial with a mean kappa of 0.70 ( 95 % confidence interval [ CI ] : 0.57 , 0.83 ) ( range : 0.38 - 1.0 ) . Kappas recorded for the other instruments were 0.63 ( 95 % CI : 0.38 , 0.78 ) for enhanced OQAQ and 0.40 ( 95 % CI : 0.29 , 0.50 ) for the Sacks ' instrument . The ICC of the total score for AMSTAR was 0.84 ( 95 % CI : 0.65 , 0.92 ) compared with 0.91 ( 95 % CI : 0.82 , 0.96 ) for OQAQ and 0.86 ( 95 % CI : 0.71 , 0.94 ) for the Sacks ' instrument . AMSTAR proved easy to apply , each review taking about 15 minutes to complete . CONCLUSIONS AMSTAR has good agreement , reliability , construct validity , and feasibility . These findings need confirmation by a broader range of assessors and a more diverse range of review Abstract Within the framework of an on-going prospect i ve clinical study begun in 1985 , 120 adhesive-fixed partial dentures ( AFPD ) continued to be examined . The manufacture and the fitting of the AFPDs were carried out following a st and ard procedure . The preparation technique and the metal framework conditioning ( silica-coating , s and blasting and electrochemical etching ) has varied throughout the duration of the study . Using Kaplan-Meier analysis , the survival rate was determined and an analysis of risk with regard to location factors ( anterior , posterior ; maxilla , m and ible ) , conditioning and preparation techniques ( retentive/non-retentive ) was determined using the Cox regression model . The location of the AFPD had no influence on the survival rate . The survival time was determined mainly by the preparation technique . Strict preparation of seating grooves and pin holes made a 95 % survival rate possible after 10 years ( Kaplan-Meier estimation ) . Without retention , the risk of failure increased by a factor of 3.7 OBJECTIVES This prospect i ve clinical study evaluated the performance of indirect , anterior , surface-retained , fibre-reinforced-composite restorations ( ISFRCR ) . METHODS Between June-2003 and January-2011 , a total of 134 patients ( 83 females , 51 males , 16 - 68 years old ) received 175 ISFRCRs ( local ethical registration number : 14/9/4 ) . All restorations were made indirectly on a plaster model using unidirectional E-glass fibres ( everStick C&B , StickTech ) in combination with a laboratory resin composite ( Dialogue , Schütz Dental ) and cemented according to the instructions of 4 resin cements [ ( RelyX ARC , 3M-ESPE , n=61 ) , Bifix DC , VOCO , n=45 ) , Variolink II ( Ivoclar Vivadent , n=32 ) and Multilink ( Ivoclar Vivadent , n=37 ) ] . After baseline recordings , patients were followed at 6 months and thereafter annually up to 7.5 years . The evaluation protocol involved technical ( chipping , debonding or fracture of tooth/restoration ) and biological failures ( caries ) . RESULTS Mean observation period was 58 months . Altogether , 13 failures were observed [ survival rate : 97.7 % ] ( Kaplan-Meier ) . One catastrophic fracture [ ( cement : RelyX ARC ) , eight partial debonding ( cement : Bifix DC ( 5 ) , Multilink ( 1 ) , RelyX ARC ( 1 ) , Variolink II ( 1 ) ] and four delaminations of veneering composite [ ( cement : Bifix DC ( 2 ) , RelyX ARC ( 1 ) , Multilink ( 1 ) ] were observed . Except one replacement , all defective restorations were repaired or recemented . Annual failure rate of ISFRCRs was 1.73 % . The survival rates with the four resin cements did not show significant differences ( RelyX ARC : 98.3 % ; Bifix DC : 93.5 % ; Variolink 2 : 100 % ; Multilink : 100 % ) ( p=0.114 ) . Secondary caries did not occur in any of the teeth . CONCLUSION The 3-unit anterior indirect surface-retained resin-bonded FRC FDPs showed similar clinical survival rate when cemented with the resin cements tested . Experienced failures in general were due to debonding of the restoration or delamination of the veneering composite . CLINICAL SIGNIFICANCE 3-unit surface retained resin-bonded FRC FDPs could be considered minimal invasive and cost-effective alternatives to conventional tooth- or implant-borne FDPs .  Failures were mainly repairable in the form of chipping or debonding depending on the resin cement type 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 PURPOSE To retrospectively evaluate the 6-year survival rates and technical/ biologic complication rates of single-retainer glass-ceramic resin-bonded fixed dental prostheses ( RBFDPs ) .  MATERIAL S AND METHODS Forty patients with 49 anterior/posterior glass-ceramic RBFDPs were included . The RBFDPs  replaced 11 maxillary/m and ibular central incisors , 18 lateral incisors , 18 premolars , and 2 molars . Patients willing to participate were clinical ly and radiologically examined . The technical outcome was assessed with modified United States Public Health Service criteria . Fracture and /or chipping of the restoration , occlusal wear , marginal adaptation , marginal discoloration , shape , surface texture , and esthetic integration were recorded . Tooth vitality and postoperative sensitivity were tested . The following biologic parameters were assessed at test and control teeth : probing pocket depth , gingival recession , attachment loss , bleeding on probing , furcation involvement , and periodontal mobility . Statistical analysis was performed with exact 95 % confidence intervals to relative frequencies and the paired t test . RESULTS Twenty-eight patients with 35 RBFDPs participated . The mean follow-up of the RBFDPs was 6 years . Twelve patients with 14 RBFDPs were not willing to participate or not available . No catastrophic failures occurred . The 6-year survival rate 
    Output:
    
Technical complications were the main reason for failures .
The 5-year clinical performance of RBFPDs is similar to the performance of conventional fixed partial dentures ( FPDs ) and implant-supported crowns .