title: Receptor activator of nuclear factor kappa-B gene polymorphisms in Iranian periodontitis and peri-implantitis patients.
abstract: OBJECTIVE
  Peri-implantitis and periodontitis are inflammatory and infectious diseases of implant and tooth-supporting tissues. Recently, the role of gene polymorphisms of immune response components in the relevant pathogenesis has been investigated. The present study was the first to evaluate the relationship between two known single nucleotide polymorphisms (SNPs) of the receptor activator of nuclear factor kappa-β (RANK) gene (rs3018362 and rs35211496) in chronic periodontitis and peri-implantitis patients in an Iranian population.
  
  
  METHODS
  Eighty-one periodontally healthy patients, 38 patients with peri-implantitis, and 74 patients with chronic periodontitis were enrolled in this study. DNA was extracted from blood arm vein samples by using Miller's salting out technique according to the manufacturer's instructions given in the extraction kit. The concentration of DNA samples was measured using a spectrophotometer. The genetic polymorphisms of the RANK gene were evaluated using a competitive allele specific polymerase chain reaction (KBioscience allele specific PCR) technique. Differences in the frequencies of genotypes and alleles in the diseased and healthy groups were analyzed using chi-squared statistical tests (P<0.05).
  
  
  RESULTS
  Analysis of rs35211496 revealed statistically significant differences in the expression of the TT, TC, and CC genotypes among the three groups (P=0.00). No statistically significant difference was detected in this respect between the control group and the chronic periodontitis group. The expression of the GG, GA, and AA genotypes and allele frequencies (rs3018362) showed no statistically significant difference among the three groups (P=0.21).
  
  
  CONCLUSIONS
  The results of this study indicate that the CC genotype of the rs35211496 RANK gene polymorphism was significantly associated with peri-implantitis and may be considered a genetic determinant for peri-implantitis, but this needs to be confirmed by further studies in other populations.
authors.affiliation: Department of Periodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mahdi
authors.identifier: 0000-0002-6131-2791
authors.initials: M
authors.lastname: Kadkhodazadeh
authors.affiliation: Department of Periodontics, School of Dentistry, International Branch, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Zahra
authors.identifier: 0000-0003-0847-7076
authors.initials: Z
authors.lastname: Baghani
authors.affiliation: Private Practice, Mashhad, Iran.
authors.forename: Ahmad Reza
authors.identifier: 0000-0002-6015-5966
authors.initials: AR
authors.lastname: Ebadian
authors.affiliation: Department of Periodontics, School of Dentistry, International Branch, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Zahra
authors.identifier: 0000-0002-5815-0074
authors.initials: Z
authors.lastname: Kaghazchi
authors.affiliation: Department of Periodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Reza
authors.identifier: 0000-0002-8053-3928
authors.initials: R
authors.lastname: Amid
keywords: Genetic polymorphism; Peri-implantitis; Periodontitis; Receptor activator of nuclear factor-kappa B