title: Long-term outcomes of three types of implant-supported mandibular overdentures in smokers.
abstract: OBJECTIVE
  The aim of the study was to compare the differences in the long-term clinical and radiologic effects for three different treatment strategies with implant-supported overdentures in the edentulous mandible, with a special emphasis on smoking.
  
  
  METHODS
  In a randomized- controlled clinical trial, 110 edentulous patients participated. Thirty-six patients were treated with an overdenture supported by two implants with ball attachments (2IBA), 37 patients with an overdenture supported by two implants with a bar (2ISB) and 37 patients with an overdenture supported by four implants with a triple bar (4ITB). After a mean evaluation period of 8.3 years, the clinical and radiographic parameters were evaluated.
  
  
  RESULTS
  Ninety-four out of the original 110 patients (=85%) were evaluated. In the 2IBA group, the plaque index was significantly lower (vs. 2ISB, P=0.013; vs. 4ITB, P=0.001) than in the other groups, but there was no correlation with the other peri-implant parameters. In the 4ITB group, the marginal bone loss was significantly higher than that in the two implant groups. The maximal probing depth was correlated with peri-implant bone loss (P=0.011). Smoking almost doubled marginal bone loss irrespective of the treatment strategy chosen.
  
  
  CONCLUSIONS
  Patients with two implants show less marginal bone loss than those with four implants. Smoking is a risk factor for the survival of dental implants in the long run.
authors: Department of Oral Implantology and Prosthodontics, Academic Centre for Dentistry Amsterdam, Research Institute MOVE, University of Amsterdam and Free University, Amsterdam, The Netherlands. geertstoker@wxs.nl
authors: Geert
authors: G
authors: Stoker
authors: Rien
authors: R
authors: van Waas
authors: Daniël
authors: D
authors: Wismeijer
mesh_terms: D016301:Alveolar Bone Loss / Q000453:epidemiology*; D000704:Analysis of Variance; D003774:Dental Plaque Index; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D003781:Denture Retention; D003828:Denture, Overlay; D005260:Female; D006801:Humans; D007575:Jaw, Edentulous / Q000601:surgery*; D008297:Male; D008334:Mandible / Q000601:surgery*; D008875:Middle Aged; D057873:Peri-Implantitis / Q000453:epidemiology*; D010512:Periodontal Index; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D016896:Treatment Outcome