title: Dental implants inserted in fresh extraction sockets versus healed sites: a systematic review and meta-analysis.
abstract: OBJECTIVE
  To test the null hypothesis of no difference in the implant failure rates, postoperative infection and marginal bone loss for the insertion of dental implants in fresh extraction sockets compared to the insertion in healed sites, against the alternative hypothesis of a difference.
  
  
  METHODS
  Main search terms used in combination: dental implant, oral implant, resh extraction socket, immediate placement, immediate insertion, immediate implant.
  
  
  METHODS
  An electronic search was undertaken in July/2014, in PubMed, Web of Science, Cochrane Oral Health Group Trials Register plus hand-searching.
  
  
  METHODS
  Eligibility criteria included clinical human studies, either randomized or not.
  
  
  CONCLUSIONS
  The search strategy resulted in 73 publications, with 8,241 implants inserted in sockets (330 failures, 4.00%), and 19,410 in healed sites (599 failures, 3.09%). It is suggested that the insertion of implants in fresh extraction sockets affects the failure rates (RR 1.58, 95% CI 1.27-1.95, P<0.0001). The difference was not statistically significant when studies evaluating implants inserted in maxillae or in mandibles were pooled, or when the studies using implants to rehabilitate patients with full-arch prostheses were pooled; however, it was significant for the studies that rehabilitated patients with implant-supported single crowns and for the controlled studies. There was no apparent significant effect on the occurrence of postoperative infection or on the magnitude of marginal bone loss. The results should be interpreted with caution due to the potential for biases and to the presence of uncontrolled confounding factors in the included studies, most of them not randomized.
  
  
  CONCLUSIONS
  The question whether immediate implants are more at risk for failure than implants placed in mature bone has received increasing attention in the last years. As the philosophies of treatment alter over time, a periodic review of the different concepts is necessary to refine techniques and eliminate unnecessary procedures. This would form a basis for optimum treatment.
authors.affiliation: Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden. Electronic address: bruno.chrcanovic@mah.se.
authors.forename: Bruno Ramos
authors.initials: BR
authors.lastname: Chrcanovic
authors.affiliation: Department of Biomaterials, Göteborg University, Göteborg, Sweden; Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.
authors.forename: Tomas
authors.initials: T
authors.lastname: Albrektsson
authors.affiliation: Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.
authors.forename: Ann
authors.initials: A
authors.lastname: Wennerberg
mesh_terms: D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D019232:Dental Restoration Failure; D006801:Humans; D008334:Mandible / Q000473:pathology / Q000601:surgery; D008437:Maxilla / Q000473:pathology / Q000601:surgery; D011184:Postoperative Period; D014081:Tooth Extraction; D020390:Tooth Socket / Q000473:pathology / Q000601:surgery*
chemical_list: D015921:Dental Implants
keywords: Dental implants; Fresh extraction socket; Healed site; Immediate insertion; Implant failure rate; Meta-analysis