title: Clinical comparison of metal ceramic resin-bonded fixed dental prostheses with a conventional and a mixed retainer design.
abstract: BACKGROUND
  Little is known about the clinical performance of fixed dental prostheses that rigidly connect adhesive retainers and crowns.
  
  
  OBJECTIVE
  The purpose of this retrospective analysis was to assess and compare the clinical performance of resin-bonded fixed dental prostheses with a conventional and a mixed retainer design.
  
  
  METHODS
  Included as participants were all patients of the hospital since 2004 with regular clinical follow-up who were treated with 3-unit or 4-unit metal ceramic resin-bonded fixed dental prostheses with a conventional 2-adhesive retainer design (conventional group) or with a mixed type combining an adhesive retainer with a crown or a partial crown retainer (mixed group). The analysis included 84 participants with a total of 57 (64%) prostheses in the conventional group and 32 (36%) prostheses in the mixed group. Treatment and data collection were standardized. Cumulative survival without failure (defined as a restoration in need of replacement), chipping, and debonding were estimated by the Kaplan-Meier method and compared for the groups (log-rank test) (α=.05).
  
  
  RESULTS
  During a mean observation period of 4.1 years (SD, 2.5 years; minimum, 0.4 years; maximum, 9.4 years), 12 complications occurred in 10 restorations. Defects of the ceramic veneer (n=6) were observed most frequently. The estimated 5-year failure-free survival rate was 97.4% (standard error, .025) in the conventional group and 95% (standard error, .049) in the mixed group (log-rank, P=.32). The 5-year cumulative survival rate without chipping was 90.7% (standard error, .064) for the conventional group and 93.8% (standard error, .061) for the mixed group (log-rank, P=.44). The 5-year cumulative survival rate without debonding was 95.1% (standard error, .034) for the conventional group and 91.5% (standard error, .058) for the mixed group (log-rank, P=.54).
  
  
  CONCLUSIONS
  Limited by a small sample size and a short follow-up period, the findings of this retrospective analysis indicate that the clinical performance, in terms of survival and the incidence of complications, is comparable for conventional resin-bonded fixed dental prostheses and those that rigidly connect an adhesive wing and a partial or complete crown. Acceptable 5-year survival and complication rates imply that the medium-term prognosis for resin-bonded restorations with a retentive preparation design is comparable with that for conventional fixed dental prostheses.
authors.affiliation: Assistant Professor, Department of Prosthodontics, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany. Electronic address: Wolfgang.Boemicke@med.uni-heidelberg.de.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Boemicke
authors.affiliation: Assistant Professor, Department of Prosthodontics, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Kappel
authors.affiliation: Assistant Professor, Department of Prosthodontics, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Stober
authors.affiliation: Director, Department of Prosthodontics, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Rammelsberg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002516:Ceramics / Q000737:chemistry; D003442:Crowns; D000044:Dental Abutments; D003764:Dental Materials / Q000737:chemistry; D019232:Dental Restoration Failure; D003801:Dental Veneers; D003779:Denture Design; D003781:Denture Retention / Q000295:instrumentation*; D003830:Denture, Partial, Fixed; D016379:Denture, Partial, Fixed, Resin-Bonded; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D016876:Metal Ceramic Alloys / Q000737:chemistry*; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D013499:Surface Properties; D016019:Survival Analysis; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D003764:Dental Materials; D016876:Metal Ceramic Alloys