title: Retrospective analysis of implant survival and the influence of periodontal disease and immediate placement on long-term results.
abstract: OBJECTIVE
  The purpose of this study was to investigate the cumulative survival rates of dental implants placed in a private periodontal practice and the effects of periodontal disease and immediate placement on implant survival.
  
  
  METHODS
  A retrospective chart review was conducted on 149 consecutive patients. Each patient had a single implant placed. For the purpose of analysis, patients were divided into 2 groups: those who were periodontally healthy and those who had periodontal disease. Implants were placed into available bone either immediately or after a healing period. All failed implants were removed and recorded. The effects of periodontal status and placement time on implant survival were evaluated using Cox proportional hazards regression and log-rank tests.
  
  
  RESULTS
  Of the 149 implants in the study, 22 failed during the observation period. The 127 censored cases (i.e., implants that had not failed at the end of the observational period) were observed for a mean of 943 days (SD 932, range 35 to 4,030). Failed implants were observed for a mean of 722 days (SD 1,026, range 18 to 3,548). The presence of periodontal disease appeared to be associated with a greater failure rate, but there was no observed effect associated with time of placement. The percentages of censored immediate placement cases and delayed placement cases were nearly identical. Among the 77 implants associated with periodontal disease, placement time was not strongly associated with percentage censored. Forty-three of the 55 immediately placed implants (78.18%) and 18 of the 22 implants (81.18%) whose placement was delayed were censored. Both Cox proportional hazards regression and log-rank tests established that survival was adversely affected by periodontal disease (P < .05) but unaffected by time of placement (P > .50). The lower 1-sided 95% confidence limit for median survival time was 3,548 days for patients without periodontal disease and 1,799 days for patients with disease.
  
  
  CONCLUSIONS
  Implant survival was compromised by a history of periodontitis but not affected by immediate or delayed placement.
authors.affiliation: University of Pennsylvania School of Dentistry, Philadelphia, Pennsylvania, USA. cevian@msn.com
authors.forename: Cyril I
authors.initials: CI
authors.lastname: Evian
authors.forename: Robert
authors.initials: R
authors.lastname: Emling
authors.forename: Edwin S
authors.initials: ES
authors.lastname: Rosenberg
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Waasdorp
authors.forename: Wendy
authors.initials: W
authors.lastname: Halpern
authors.forename: Shalin
authors.initials: S
authors.lastname: Shah
authors.forename: Marela
authors.initials: M
authors.lastname: Garcia
mesh_terms: D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D017268:Dental Prosthesis Retention; D019232:Dental Restoration Failure; D006801:Humans; D010518:Periodontitis / Q000150:complications*; D011183:Postoperative Complications; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D013997:Time Factors; D020390:Tooth Socket
chemical_list: D015921:Dental Implants