title: Retrospective study of the survival and associated risk factors of wedge-shaped implants.
abstract: OBJECTIVE
  To assess the long-term behavior of wedge-shaped implants and evaluate the influence of the associated risk factors on implant survival rates.
  
  
  METHODS
  A retrospective review of clinical records of patients treated with wedge-shaped implants between 1992 and 2011 was conducted. Data on patient sex, age, smoking habits, and history of periodontitis; details of implant length, diameter, angle, and location; and data on surgical, reconstructive, and prosthetic procedures, and systemic disease were selected for analysis.
  
  
  RESULTS
  A total of 1,169 implants placed in 154 patients (mean age 55.17 ± 11.33 years) were evaluated. Women received 637 implants, and men received 532 implants; 60.4% were placed in patients who were undergoing periodontal maintenance care, 17.9% in smokers, 17.7% in hypertensive patients, 5.7% in diabetic patients, and 4.4% in cardiac patients. The mean overall survival for implants was 194.26 ± 9.91 months. Seventy-three implants were lost: 3 before implant loading and 70 after loading. The cumulative survival rates at 5 and 10 years were 96.6% (confidence interval [CI]: 95.5% to 97.7%) and 91.8% (CI: 90.1% to 94.1%), respectively. Univariate analysis indicated tobacco smoking (P = .014) and implant location (P < .001) as significant risk factors for implant failure. The multivariate analysis showed tobacco smoking (P = .016), location (P = .001), and male sex (P = .038) as significant, and the latter factor was associated with previous periodontal disease.
  
  
  CONCLUSIONS
  Overall survival of the wedge-shaped implant showed good long-term results. Male sex, tobacco smoking, and posterior maxillary location were associated with a greater risk of implant failure.
authors.affiliation: School od Dentistry, University of San Martin Martin de porres, Lima, Peru.
authors.forename: Rafael
authors.initials: R
authors.lastname: Morales-Vadillo
authors.forename: Fabiola Pessoa Pereira
authors.initials: FP
authors.lastname: Leite
authors.forename: Janet
authors.initials: J
authors.lastname: Guevara-Canales
authors.forename: Henrique Duque
authors.initials: HD
authors.lastname: Netto
authors.forename: Maria das Gracas Afonso
authors.initials: Md
authors.lastname: Miranda Chaves
authors.forename: Fernando
authors.initials: F
authors.lastname: Cruz
authors.forename: Gustavo
authors.initials: G
authors.lastname: Cruz
authors.forename: Silvia
authors.initials: S
authors.lastname: Cruz-Pierce
authors.forename: Mauro
authors.initials: M
authors.lastname: Cruz
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D003758:Dental Implantation, Endosseous / Q000295:instrumentation* / Q000379:methods / Q000706:statistics & numerical data; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010518:Periodontitis / Q000601:surgery; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects; D055815:Young Adult