title: 5-year clinical experience with BTI dental implants: risk factors for implant failure.
abstract: OBJECTIVE
  The aims of this study were to identify with appropriate statistical tests the risk factors associated with implant failure and to evaluate the long-term survival of dental implants using implant loss as an outcome variable and performing an implant-, surgery- and patient-based analysis of failures.
  
  
  METHODS
  A retrospective cohort study design was used. One thousand sixty patients received 5787 BTI implants during the years of 2001-2005 in Vitoria, Spain. The potential influence of demographic items, clinical items, surgery-dependent items and prosthetic variables on implant survival was studied. Implant survival was analysed using a life-table analysis. Cox proportional hazards regression was used to identify risk factors related to implant failure.
  
  
  RESULTS
  Smoking habits, implant position, implant staging (two-stage implants) and the implementation of special techniques were statistically correlated with lower implant survival rates. Two risk factors associated with implant failure were detected in this study: implant staging (two-stage implants) and the use of special techniques. Additionally, the overall survival rates of BTI implants were 99.2%, 96.4% and 96% for the implant-, surgery- and patient-based analysis, respectively. Totally, 28 out from 5787 implants (0.48%) were lost during the observation period. Most of the patients with implant failure (69.6%) presented chronic or aggressive periodontitis.
  
  
  CONCLUSIONS
  Implant staging and the use of special techniques are risk factors for implant failure.
authors.affiliation: Biotechnology Institute I MAS D, Vitoria, Spain. eduardoanitua@eduardoanitua.com
authors.forename: Eduardo
authors.initials: E
authors.lastname: Anitua
authors.forename: Gorka
authors.initials: G
authors.lastname: Orive
authors.forename: José Javier
authors.initials: JJ
authors.lastname: Aguirre
authors.forename: Bruno
authors.initials: B
authors.lastname: Ardanza
authors.forename: Isabel
authors.initials: I
authors.lastname: Andía
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density / Q000502:physiology; D018786:Bone Substitutes / Q000627:therapeutic use; D016025:Bone Transplantation; D015331:Cohort Studies; D003758:Dental Implantation, Endosseous / Q000379:methods; D015921:Dental Implants / Q000706:statistics & numerical data*; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D008903:Minerals / Q000627:therapeutic use; D010518:Periodontitis / Q000150:complications; D053657:Platelet-Rich Plasma; D012189:Retrospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D016019:Survival Analysis
chemical_list: C077540:Bio-Oss; D018786:Bone Substitutes; D015921:Dental Implants; D036341:Intercellular Signaling Peptides and Proteins; D008903:Minerals