title: Analysis of osteoprotegerin (OPG) gene polymorphism in Iranian patients with chronic periodontitis and peri-implantitis. A cross-sectional study.
abstract: OBJECTIVE
  Receptor activator for nuclear factor kappa B ligand (RANKL)/RANK/OPG pathway plays a redundant role in osteoclastogenesis, osteoclast activation and regulation of bone resorption. Recently, single nucleotide polymorphisms (SNP) have been reported as a co-factor in pathogenesis of inflammatory diseases. The aim of this study was to investigate the relationship between osteoprotegerin (OPG) gene polymorphisms and chronic periodontitis and peri-implantitis in an Iranian population.
  
  
  METHODS
  77 patients with chronic periodontitis (CP), 40 patients with peri-implantitis (PI) and 89 periodontally healthy subjects were enrolled in this study. A total of 5 ml of blood was obtained from the arm vein of participants. DNA was extracted based on the salting out method. Two functional SNPs (T950C and G1181C) were analysed by using polymerase chain reaction and restriction fragment length polymorphism (PCR_RFLP). The prevalence differences in three batches were evaluated by chi-square test.
  
  
  RESULTS
  An evaluation of the T950C genotype found that there was no statistical difference between groups. A comparison of the G1181C genotype distribution between peri-implantitis and chronic periodontitis groups, and between peri-implantitis and normal groups found that the frequency of the CC genotype was significantly higher in patients with peri-implantitis (P = 0.005).
  
  
  CONCLUSIONS
  Our results indicate that a SNP at G1181C is associated with the presence of PI.
authors.affiliation: Periodontics Department, Shahid Beheshti University of Medical Sciences, Tehran, Iran. kadkhodazadehmahdi@yahoo.com
authors.forename: Mahdi
authors.initials: M
authors.lastname: Kadkhodazadeh
authors.forename: Zahra Alizadeh
authors.initials: ZA
authors.lastname: Tabari
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Ardakani
authors.forename: Ahmad Reza
authors.initials: AR
authors.lastname: Ebadian
authors.forename: Azam
authors.initials: A
authors.lastname: Brook
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D055113:Chronic Periodontitis / Q000235:genetics*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007492:Iran; D008297:Male; D053244:Osteoprotegerin / Q000235:genetics*; D057873:Peri-Implantitis / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D055815:Young Adult
chemical_list: D053244:Osteoprotegerin