title: Clinical Outcome of Double Crown-Retained Mandibular Removable Dentures Supported by a Combination of Residual Teeth and Strategic Implants.
abstract: OBJECTIVE
  There is a lack of data regarding the clinical outcome of removable partial dentures (RPDs) supported by a combination of residual natural teeth and implants placed in strategic positions. The aim of the present case series was to conduct a retrospective investigation of the clinical outcome of mandibular tooth-implant-retained partial dentures (TIRPD) rigidly retained via telescopic double crowns.
  
  
  METHODS
  Between 1999 and 2010, 18 patients with reduced residual dentition (1 to 3 natural abutment teeth) and in need of an RPD received 1 to 3 implants in strategic positions for support of the removable prostheses. All TIRPDs were rigidly retained by telescopic crowns according to the Marburg Double Crown (MDC) technique; all prostheses were placed in a private practice. Tooth/implant survival and success rates, prosthetic maintenance requirements, and peri-implant parameters were analyzed retrospectively using patient records and clinical examinations during the final recall appointments. Only patients attending at least annual supportive post-implant hygiene therapy visits (SIT) were included.
  
  
  RESULTS
  After a mean functional period of 5.84 ± 3 years (range: 3.01-12.21), 14 patients with 14 dentures supported by 24 implants and 27 teeth (mean number of abutments: 3.6) were available for assessment. Four teeth (survival rate: 85.19%) and no implants (survival rate: 100%) were lost. Peri-implantitis was observed around one implant (4.17%). All 14 dentures were functional (survival rate: 100%) and required only limited maintenance (i.e., screw loosening, acrylic resin fracture repairs, relining) amounting to 0.086 treatments per patient per year (T/P/Y).
  
  
  CONCLUSIONS
  Within the limitations of this case series, it can be concluded that TIRPDs retained via MDCs might represent a viable treatment option in mandibles with few remaining abutment teeth. Further long-term clinical evaluations with a greater sample size are needed for a more detailed evaluation of this treatment concept.
authors.affiliation: Private Practice, Hanau, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Rinke
authors.affiliation: Department of Preventive Dentistry, Periodontology and Cariology, University Medical Center Göttingen, Göttingen, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Ziebolz
authors.affiliation: Department of Operative Dentistry and Periodontology, University of Freiburg, Freiburg, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Ratka-Krüger
authors.affiliation: Private Practice, Hofgeismar, Germany.
authors.forename: Eberhard
authors.initials: E
authors.lastname: Frisch
mesh_terms: D003442:Crowns; D000044:Dental Abutments; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D003828:Denture, Overlay; D005500:Follow-Up Studies; D006801:Humans; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D015921:Dental Implants
keywords: Maintenance; peri-implantitis; success; survival; technical complications; telescopic crown