title: Dentoalveolar reconstructive procedures as a risk factor for implant failure.
abstract: OBJECTIVE
  Dentoalveolar reconstructive procedures (DRPs) are commonly used to enhance deficient implant recipient sites. It is unclear, however, if these procedures are independent risk factors for implant failure. The specific aim of this study was to assess the use of DRPs as a risk factor for implant failure.
  
  
  METHODS
  To address the research aim, we used a retrospective cohort study design and a study sample derived from the population of patients who had one or more implants inserted between May 1992 and July 2000. The main predictor variable was the use of DRPs, such as external or internal sinus lifts, onlay bone grafting, or guided-tissue regeneration with autogenous bone grafts or autogenous bone graft substitutes, to enhance the recipient sites before implant insertion. The major outcome variable was implant failure. Appropriate descriptive, bivariate, and multivariate statistics were computed.
  
  
  RESULTS
  The study sample was composed of 677 patients who had 677 implants randomly selected (1 implant per patient) for analysis. The overall 1- and 5-year implant survival rates were 95.2% and 90.2%, respectively. Bivariate analyses revealed 4 factors statistically or nearly statistically associated with implant failure: current tobacco use, implant length, implant staging, and type of prosthesis (P <.15). In the multivariate model, patients with DRPs did not have a statistically significant increased risk for implant failure (odds ratio = 1.4, P =.3).
  
  
  CONCLUSIONS
  The results of this study suggest that the use of DRPs to reconstruct deficient implant recipient sites was not an independent risk factor for implant failure in either the unadjusted or adjusted analyses.
authors.affiliation: Harvard School of Dental Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.
authors.forename: Valerie V
authors.initials: VV
authors.lastname: Woo
authors.forename: Sung-Kiang
authors.initials: SK
authors.lastname: Chuang
authors.forename: Shadi
authors.initials: S
authors.lastname: Daher
authors.forename: Ali
authors.initials: A
authors.lastname: Muftu
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Dodson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000540:Alveolar Ridge Augmentation / Q000009:adverse effects / Q000379:methods*; D018786:Bone Substitutes / Q000627:therapeutic use; D016025:Bone Transplantation; D015331:Cohort Studies; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D005260:Female; D016557:Guided Tissue Regeneration, Periodontal; D006801:Humans; D008297:Male; D008437:Maxilla / Q000601:surgery; D008443:Maxillary Sinus / Q000601:surgery; D008875:Middle Aged; D015999:Multivariate Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D012907:Smoking; D016019:Survival Analysis; D014182:Transplantation, Autologous
chemical_list: D018786:Bone Substitutes; D015921:Dental Implants