title: Prognosis of implants and abutment teeth under combined tooth-implant-supported and solely implant-supported double-crown-retained removable dental prostheses.
abstract: OBJECTIVE
  Objective of this study was to evaluate the incidence of complications in dental implants and abutment teeth used for combined tooth-implant- and solely implant-supported double crown-retained removable dental prostheses (RDPs).
  
  
  METHODS
  Patients were selected from a prospective clinical study. Seventy-three RDPs retained by 234 implants and 107 abutment teeth were placed in 39 men and 22 women with a mean age of 65 years. Forty-five RDPs were located in the maxilla and 28 in the mandible. Thirty-four RDPs were solely implant-supported and 39 were combined tooth-implant-supported. Kaplan-Meier analysis was used to estimate success defined as survival without severe abutment-related complications, and Cox regression was used to isolate the most relevant prognostic risk factors.
  
  
  RESULTS
  After a median observation period of 2.7 years for the RDPs, six implants failed and eleven implants were diagnosed with peri-implantitis. Four abutment teeth were extracted, and three abutment teeth showed severe complications requiring extended interventions. For both abutment teeth and implants, Kaplan-Meier analyses revealed a 5-year probability of success of 85% for solely implant-supported RDPs and 92% for combined tooth-implant-supported RDPs. Multiple Cox regression identified RDP location (P = 0.01), age (P = 0.01), and gender (P = 0.04) as prognostic risk factors for severe implant-related complications. Solely implant-supported RPDs showed a poorer prognosis, but the risk difference did not reach statistical significance.
  
  
  CONCLUSIONS
  Preliminary data suggest that the combination of teeth and implants to support double crown-retained RDPs may result in a prognostic advantage. The present findings should be validated in independent studies.
authors.affiliation: Department of Prosthodontics, University of Heidelberg, Heidelberg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Rammelsberg
authors.forename: Gunda
authors.initials: G
authors.lastname: Bernhart
authors.forename: Justo
authors.initials: J
authors.lastname: Lorenzo Bermejo
authors.forename: Marc
authors.initials: M
authors.lastname: Schmitter
authors.forename: Stefanie
authors.initials: S
authors.lastname: Schwarz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003442:Crowns; D000044:Dental Abutments; D015921:Dental Implants; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention; D019094:Dental Prosthesis, Implant-Supported; D003832:Denture, Partial, Removable; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies
chemical_list: D015921:Dental Implants
keywords: complication; dental implants; prognosis; removable dental prosthesis; telescoping double crown