title: The effect of prosthetic margin location on caries susceptibility. A systematic review and meta-analysis.
abstract: BACKGROUND
  The prosthetic margin location relevant to the free gingival margin may influence the incidence of secondary caries due to the differences that exist between the micro-environment within the gingival crevice compared to the rest of the oral environment.
  
  
  OBJECTIVE
  The purpose of this study was to systematically review the effect of prosthetic margin placement on caries susceptibility of abutment teeth.
  
  
  METHODS
  Two independent authors identified cohort studies using MEDLINE, EMBASE, CDSR, CENTRAL, Google Scholar and Scopus through March 2012. Reference lists were also scanned. Included studies had to report on caries incidence with regard to location of prosthetic margins, with a minimum follow-up period of two years.
  
  
  RESULTS
  A total of 5,541 references were identified and, after application of the inclusion criteria, 22 studies were included in the systematic review. Random-effects meta-analysis could be made in two studies, in which secondary caries incidence did not differ between margins placed subgingivally compared to equi- or supragingivally placed margins for a follow-up period up to ten years. Indications were found of a possible lower secondary caries rate at 15 years of follow up, based on one study.
  
  
  CONCLUSIONS
  This systematic review and meta-analysis failed to detect a significantly different secondary caries rate of subgingivally located prosthetic margins in the short to mid-term (≤10 years). Due to the small number and the limitations of the included studies the results do not provide conclusive evidence as to the effect of prosthetic margin placement on the incidence of secondary caries.
authors.affiliation: Department of Oral Technology, School of Dentistry, University of Bonn, Bonn, Germany.
authors.forename: S N
authors.initials: SN
authors.lastname: Papageorgiou
authors.forename: A P
authors.initials: AP
authors.lastname: Papadelli
authors.forename: P T
authors.initials: PT
authors.lastname: Koidis
authors.forename: H P
authors.initials: HP
authors.lastname: Petridis
mesh_terms: D000044:Dental Abutments; D003731:Dental Caries / Q000209:etiology* / Q000382:microbiology; D003733:Dental Caries Susceptibility; D017267:Dental Prosthesis Design; D005881:Gingiva / Q000033:anatomy & histology*; D006801:Humans; D019231:Tooth Preparation, Prosthodontic