title: Association between susceptible genotypes to periodontitis and clinical outcomes of periodontal regenerative therapy: A systematic review.
abstract: BACKGROUND
  The aim of this review is to systematically investigate the effect of a susceptible genotype to periodontitis with the clinical outcomes of periodontal regeneration.
  
  
  METHODS
  Based on a focused question, an electronic search identified 155 unique citations. Three journals (Journal of Periodontology, Journal of Clinical Periodontology and Journal of Periodontal Research), references of relevant studies and review articles were hand-searched. Two independent reviewers implementing eligibility inclusion criteria selected the studies.
  
  
  RESULTS
  Of the 155, four studies fulfilled the inclusion criteria. All studies were published between 2000 and 2004 and the samples' size was 40 to 86 patients. Polymorphisms of Interleukin-1 (IL-1) gene were included in all. Three out of four studies failed to identify an association between susceptible genotypes to periodontitis and clinical outcomes of periodontal regeneration, while one found an association. The heterogeneity and small number of studies included prevented the conduct of a meta-analysis. No studies were identified evaluating the effect of other genotypes and as a result only IL-1 genotype studies were included.
  
  
  CONCLUSIONS
  Within the limits of the present review, no direct conclusion for the effect of a susceptible IL-1 genotype status to the clinical outcome after periodontal regeneration could be drawn. The need of more qualitative studies to explore a possible association emerges.
authors.affiliation: Division of Periodontology, Developmental and Surgical Sciences, School of Dentistry, University of Minnesota, 515 Delaware Street SE, Minneapolis, MN 55455, USA chatz005@umn.edu.
authors.forename: G-S
authors.initials: GS
authors.lastname: Chatzopoulos
authors.forename: V-P
authors.initials: VP
authors.lastname: Koidou
mesh_terms: D005838:Genotype; D006801:Humans; D007375:Interleukin-1 / Q000235:genetics; D010518:Periodontitis / Q000235:genetics* / Q000628:therapy; D011110:Polymorphism, Genetic; D016896:Treatment Outcome
chemical_list: D007375:Interleukin-1