title: Platform switch and dental implants: A meta-analysis.
abstract: OBJECTIVE
  To test the null hypothesis of no difference in the implant failure rates, marginal bone loss (MBL) and postoperative infection in patients who received platform-switched implants or platform-matched implants, against the alternative hypothesis of a difference.
  
  
  METHODS
  Main search terms used in combination: dental implant, oral implant, platform switch, switched platform, platform mismatch, and dental implant-abutment design.
  
  
  METHODS
  An electronic search without time or language restrictions was undertaken in December/2014 in PubMed/Medline, Web of Science, Cochrane Oral Health Group Trials Register plus hand-searching.
  
  
  METHODS
  Eligibility criteria included clinical human studies, either randomized or not.
  
  
  CONCLUSIONS
  Twenty-eight publications were included, with a total of 1216 platform-switched implants (16 failures; 1.32%) and 1157 platform-matched implants (13 failures; 1.12%). There was less MBL loss at implants with platform-switching than at implants with platform-matching (mean difference -0.29, 95% CI -0.38 to -0.19; P<0.00001). An increase of the mean difference of MBL between the procedures was observed with the increase in the follow-up time (P=0.001) and with the increase of the mismatch between the implant platform and the abutment (P=0.001). Due to lack of satisfactory information, meta-analyses for the outcomes 'implant failure' and 'postoperative infection' were not performed. The results of the present review should be interpreted with caution due to the presence of uncontrolled confounding factors in the included studies, most of them with short follow-up periods.
  
  
  CONCLUSIONS
  The question whether platform-matched implants are more at risk for failure and loose more marginal bone than platform-switched implants 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, forming 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: D016301:Alveolar Bone Loss / Q000517:prevention & control; D059605:Dental Implant-Abutment Design; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D006801:Humans; D016032:Randomized Controlled Trials as Topic
chemical_list: D015921:Dental Implants
keywords: Dental implants; Implant failure rate; Marginal bone loss; Meta-analysis; Platform switch; Postoperative infection