title: Immediate dental implant placement into infected vs. non-infected sockets: a meta-analysis.
abstract: OBJECTIVE
  This meta-analysis was aimed at assessing whether immediate dental implant placement into infected vs. non-infected sites produced different effects on implant failure risk and marginal bone loss.
  
  
  METHODS
  Relevant studies were identified by searching articles in PubMed, Web of Knowledge, and the Cochrane Library through February 2015 and by reviewing the reference lists of the retrieved articles. When an intervention led to dichotomous outcomes, the outcomes were expressed as risk ratios, whereas continuous outcomes were expressed as mean differences in millimeters; each had a 95% confidence interval. Study-specific estimates were combined using fixed-effects models.
  
  
  RESULTS
  A total of 1743 articles were identified following the search process. Seven studies were finally included in the meta-analysis, which comprised a total of 1586 implants and 25 failures. Compared to the immediate insertion of a dental implant into a non-infected site, the insertion of an implant into an infected site showed 116% increase in the risk of implant failure, which had borderline statistical significance (risk ratio = 2.16, 95% confidence interval: 0.97, 4.80, P = 0.058; heterogeneity: I2= 0.0%, Pheterogeneity= 0.997). With regard to marginal bone loss, we observed no statistically significant difference between insertions into infected vs. non-infected sites (mean difference = -0.04, 95% confidence interval: -0.09, 0.02, P = 0.173, heterogeneity: I2= 0.0%, Pheterogeneity= 0.765).
  
  
  CONCLUSIONS
  This meta-analysis suggests that immediately placing a dental implant into an infected site may increase the risk of implant failure. Given the presence of uncontrolled confounders in the studies that were assessed, the results should be interpreted with caution.
authors.affiliation: Department of Prosthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.|Shanghai Key Laboratory of Stomatology, Shanghai Research Institute of Stomatology, Shanghai, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Zhao
authors.affiliation: Department of Prosthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.|Shanghai Key Laboratory of Stomatology, Shanghai Research Institute of Stomatology, Shanghai, China.
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Prosthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. imxuchun@163.com.|Shanghai Key Laboratory of Stomatology, Shanghai Research Institute of Stomatology, Shanghai, China. imxuchun@163.com.
authors.forename: Chun
authors.initials: C
authors.lastname: Xu
authors.affiliation: Department of Prosthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. fqzhang@vip.163.com.|Shanghai Key Laboratory of Stomatology, Shanghai Research Institute of Stomatology, Shanghai, China. fqzhang@vip.163.com.
authors.forename: Fuqiang
authors.initials: F
authors.lastname: Zhang
mesh_terms: D015921:Dental Implants; D019232:Dental Restoration Failure; D006801:Humans; D057893:Immediate Dental Implant Loading / Q000009:adverse effects*; D010483:Periapical Diseases; D010510:Periodontal Diseases; D012307:Risk Factors; D018461:Soft Tissue Infections; D020390:Tooth Socket
chemical_list: D015921:Dental Implants
keywords: bone implant interactions; histo-pathology; surgical techniques