title: Survival analysis of endosseous implants in bone grafts used for the treatment of severe alveolar ridge atrophy.
abstract: OBJECTIVE
  The aim of the current study was to evaluate the long-term results of endosseous implants placed into autogenous bone grafts in severely atrophic alveolar ridges.
  
  
  METHODS
  A total of 871 implants were placed in 137 patients. The success rate was determined using survival analysis, log rank tests, and a cox regression analysis.
  
  
  RESULTS
  Seventy-four implant failures were encountered in 23 patients. Most implants were lost because of a lack of osseointegration at the time of abutment connection or by asymptomatic loosening during the first months thereafter. The overall 1-year cumulative survival rate (CSR) was 83.4%, with a decrease to 67.8% after 5 years. The only parameter of prognostic relevance in the multivariate analysis of the whole study population was the patients' gender, with a significantly worse prognosis in female patients (5-year CSR, 62.3%). However, when the patients were divided into edentulous and partially edentulous jaws, a change was observed in the overall significance of the parameters introduced into the analysis. In edentulous patients, the maxilla appeared to over-rule all other parameters, with a 5-year cumulative survival rate of 48.8%, whereas the mandible presented a significantly higher rate of implant survival (5-year CSR, 89.3%).
  
  
  CONCLUSIONS
  This study shows a poorer success rate in females than in males, probably because of differences in the quality of the bone grafts.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Hannover Medical School, Medizinische Hochschule Hannover, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Schliephake
authors.forename: F W
authors.initials: FW
authors.lastname: Neukam
authors.forename: M
authors.initials: M
authors.lastname: Wichmann
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000539:Alveolar Process / Q000473:pathology*; D000540:Alveolar Ridge Augmentation / Q000379:methods; D000543:Alveoloplasty / Q000379:methods; D001284:Atrophy; D016025:Bone Transplantation / Q000379:methods; D000044:Dental Abutments; D003758:Dental Implantation, Endosseous / Q000706:statistics & numerical data; D015921:Dental Implants / Q000706:statistics & numerical data; D019232:Dental Restoration Failure; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D007575:Jaw, Edentulous / Q000601:surgery; D007576:Jaw, Edentulous, Partially / Q000601:surgery; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008334:Mandible / Q000601:surgery; D008437:Maxilla / Q000601:surgery; D008875:Middle Aged; D015999:Multivariate Analysis; D016348:Osseointegration; D011379:Prognosis; D012044:Regression Analysis; D012737:Sex Factors; D016019:Survival Analysis; D014182:Transplantation, Autologous; D016896:Treatment Outcome
chemical_list: D015921:Dental Implants