title: A retrospective comparison of 1,022 implants: immediate versus nonimmediate.
abstract: OBJECTIVE
  The aim of this study was to compare the survival of implants placed in mature bone with the survival of implants placed in fresh extraction sockets in the same patients.
  
  
  METHODS
  A retrospective study of patients treated simultaneously with at least one immediate and one nonimmediate implant was carried out for the period 2005 to 2008. Data were recorded for patient age and sex; implant length, diameter, and position; and, for postextraction implants, distance between the implant and the alveolar bone.
  
  
  RESULTS
  One thousand twenty-two implants were placed in 150 patients; 480 were placed immediately and 542 were placed in mature bone. The mean implant survival rate was 93.4%; survival rates were 93.8% for immediate implants and 93.2% for nonimmediate implants. The failure rate in the maxilla was 5.2% and in the mandible it was 2.8%. The failure rate for immediate implants in the posterior maxilla was 8.5%, which was statistically significantly higher than for implants placed elsewhere. Of the failed implants, 72% were early failures.
  
  
  CONCLUSIONS
  The survival rate of implants placed in fresh extraction sockets was similar to that of implants placed in mature bone. A statistically significantly higher failure rate was seen with immediate implants placed in the posterior maxilla.
authors.affiliation: Valencia University Medical and Dental School, Valencia, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Peñarrocha-Diago
authors.forename: Carla L
authors.initials: CL
authors.lastname: Demarchi
authors.forename: Laura
authors.initials: L
authors.lastname: Maestre-Ferrín
authors.forename: Celia
authors.initials: C
authors.lastname: Carrillo
authors.forename: David
authors.initials: D
authors.lastname: Peñarrocha-Oltra
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Peñarrocha-Diago
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000539:Alveolar Process / Q000473:pathology; D003724:Dental Arch / Q000601:surgery; D003758:Dental Implantation, Endosseous / Q000706:statistics & numerical data*; D015921:Dental Implants / Q000706:statistics & numerical data*; D017267:Dental Prosthesis Design / Q000706:statistics & numerical data; D019094:Dental Prosthesis, Implant-Supported / Q000706:statistics & numerical data; D019232:Dental Restoration Failure / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D057893:Immediate Dental Implant Loading / Q000706:statistics & numerical data*; D008297:Male; D008334:Mandible / Q000473:pathology / Q000601:surgery; D008437:Maxilla / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D016348:Osseointegration / Q000502:physiology; D012189:Retrospective Studies; D016019:Survival Analysis; D013997:Time Factors; D020390:Tooth Socket / Q000473:pathology / Q000601:surgery
chemical_list: D015921:Dental Implants