title: Implant-supported mandibular overdentures retained with a milled bar: a retrospective study.
abstract: OBJECTIVE
  The aim of this retrospective study was to evaluate implant survival rate, peri-implant conditions, and prosthodontic maintenance for implant-supported mandibular overdentures rigidly retained with a milled bar.
  
  
  METHODS
  Patients with 4 interforaminal implants (cylindric or screw-type) supporting an overdenture on a milled bar treated between 1996 and 2004 were asked to participate in a retrospective study. The cumulative implant survival rate and peri-implant conditions (marginal bone loss, pocket depth, Plaque Index, Gingival Index, Bleeding Index, and calculus presence) were evaluated and compared between cylindric and screw-type implants. The incidence and type of prosthodontic maintenance and subjective patient satisfaction rating were also evaluated.
  
  
  RESULTS
  Fifty-eight of 67 patients (87.3%) and 232 implants (76 cylindric, 156 screw-type) were available for follow-up examination after a mean period of 59.2 +/- 26.9 months. The cumulative implant survival rate was 99%, and no differences in peri-implant soft tissue conditions were noted between the different implant types used. The cylindric implants showed more pronounced marginal bone resorption than the screw-type implants (1.9 +/- 0.6 mm vs 2.2 +/- 0.6 mm; P = .02) but the difference was not clinically significant. A low incidence of prosthodontic maintenance evenly distributed throughout the overall follow-up period and a high subjective satisfaction rating by the patients were noted.
  
  
  CONCLUSIONS
  Interforaminal screw-type and cylindric implants supporting a milled bar for rigid overdenture anchorage were associated with a high survival rate and excellent peri-implant conditions. The incidence of prosthodontic maintenance was low and evenly distributed throughout the follow-up period as a result of rigid denture stabilization by the milled bar. Rigid anchorage of a mandibular overdenture with a milled bar unites the prosthodontic advantages of removable and fixed prostheses. (Clinical Trial) (More than 50 references.)
authors.affiliation: Department of Prosthodontics, University of Vienna, Austria. krennmair@aon.at
authors.forename: Gerald
authors.initials: G
authors.lastname: Krennmair
authors.forename: Martin
authors.initials: M
authors.lastname: Krainhöfner
authors.forename: Eva
authors.initials: E
authors.lastname: Piehslinger
mesh_terms: D000368:Aged; D015921:Dental Implants / Q000706:statistics & numerical data; D019094:Dental Prosthesis, Implant-Supported / Q000295:instrumentation* / Q000706:statistics & numerical data; D003779:Denture Design; D003781:Denture Retention / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D003828:Denture, Overlay; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007575:Jaw, Edentulous / Q000534:rehabilitation*; D008297:Male; D008334:Mandible; D008875:Middle Aged; D017060:Patient Satisfaction; D012189:Retrospective Studies; D016019:Survival Analysis
chemical_list: D015921:Dental Implants