title: Clinical significance of interleukin-1 genotype in smoking patients as a predictor of peri-implantitis: A case-control study.
abstract: BACKGROUND
  Interleukin-1 (IL-1) is a proinflammatory cytokine that plays an important role in the pathogenesis of periodontitis, and so it might be useful to detect high-risk cases of peri-implantitis. It has been reported that IL-1 polymorphisms and smoking habit have a synergic effect, increasing the incidence of peri-implantitis. The aim of the present study was to evaluate the relationship between IL-1 gene polymorphisms and peri-implantitis in smoking patients.
  
  
  METHODS
  A case-control study was performed in 27 patients with peri-implantitis and 27 patients with healthy implants. All patients included were smokers. IL-1A-C889T, IL-1B+C3953T and IL-1RN+T2018C were identified by polymerase chain reaction (PCR) amplification in order to establish a relation between these variables and the presence of peri-implantitis. A bivariate analysis was performed and odds-ratio (OR) were calculated.
  
  
  RESULTS
  The incidence of peri-implantitis was significantly higher in patients with previous history of periodontitis (p=0.024; OR=10.9). Both groups were similar regarding IL-1A-C889T, IL-1B+C3953T and IL-1RN+T2018C genotypes. No increased risk in heavy smokers with IL-1 polymorphism was found.
  
  
  CONCLUSIONS
  IL-1 genotypes do not seem to be good predictors of peri-implantitis in the great majority of smoking patients. Furthermore, no synergic effect was found between IL-1 genotypes and heavy smokers. Patients with a previous history of periodontitis were more prone to peri-implantitis.
authors.affiliation: Faculty of Dentistry. Campus de Bellvitge, University of Barcelona, C/ Feixa Llarga, s/n, Pavelló Govern, 2 planta, Despatx 2.9, 08907 L'Hospitalet de Llobregat, Barcelona Spain, rui@ruibf.com.
authors.forename: Cristina
authors.initials: C
authors.lastname: García-Delaney
authors.forename: Maria-Ángeles
authors.initials: MÁ
authors.lastname: Sánchez-Garcés
authors.forename: Rui
authors.initials: R
authors.lastname: Figueiredo
authors.forename: Alba
authors.initials: A
authors.lastname: Sánchez-Torres
authors.forename: Cosme
authors.initials: C
authors.lastname: Gay-Escoda
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D005838:Genotype; D006801:Humans; D007375:Interleukin-1 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D057873:Peri-Implantitis / Q000235:genetics*; D011110:Polymorphism, Genetic; D012189:Retrospective Studies; D012907:Smoking / Q000235:genetics*; D055815:Young Adult
chemical_list: D007375:Interleukin-1