title: Impact of IL-1 genotype and smoking status on the prognosis of osseointegrated implants.
abstract: OBJECTIVE
  This study evaluated the impact of the IL-1 genotype and smoking status on the prognosis and development of complications of osseointegrated implants.
  
  
  METHODS
  The clinical charts of 180 consecutively admitted patients were analyzed with respect to the occurrence of biological complications in conjunction with oral implants. Biologic complications were defined as clinical conditions with suppuration from the peri-implant sulcus, development of a fistula or peri-implantitis with radiologic bone loss. All patients had received one or more ITI dental implants, which had been in function for at least 8 (range: 8-15) years. This patient population had received 292 implants. From these, 51 implants in 34 patients showed late (infectious) biologic complications, and 241 implants had survived without any biologic complications at all.
  
  
  RESULTS
  Of the 180 patients, 53 were smokers, who were subdivided in a series of classes according to their intensity of smoking and 127 were never smokers. Sixty-four of 180 (36%) patients tested positive for the IL-1 genotype polymorphism. This prevalence corresponds to previous reports for the prevalence of European descent populations. The results for the non-smoking group indicated no significant correlation between implant complications and a positive IL-1 genotype. However, there was a clear association for heavy smokers between a positive IL-1 genotype and implant complications. 6 of 12 or half of the heavy smokers and IL-1 genotype-positive patients had either an implant failure, i.e. loss of implant, or a biologic complication during the follow-up period.
  
  
  CONCLUSIONS
  These findings have led to the conclusion that there is a synergistic effect between a positive IL-1 genotype and smoking that puts dental implants at a significantly higher risk of developing biologic complications during function.
authors.affiliation: Department of Oral Surgery and Stomatology, School of Dental Medicine, University of Berne, Berne, Switzerland.
authors.forename: Boris
authors.initials: B
authors.lastname: Gruica
authors.forename: Hwa-Ying
authors.initials: HY
authors.lastname: Wang
authors.forename: Niklaus P
authors.initials: NP
authors.lastname: Lang
authors.forename: Daniel
authors.initials: D
authors.lastname: Buser
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000209:etiology / Q000235:genetics; D003751:Dental Fistula / Q000209:etiology; D003758:Dental Implantation, Endosseous / Q000379:methods; D015921:Dental Implants / Q000009:adverse effects*; D019232:Dental Restoration Failure; D005260:Female; D006801:Humans; D007375:Interleukin-1 / Q000235:genetics*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016348:Osseointegration / Q000235:genetics*; D010518:Periodontitis / Q000209:etiology; D011110:Polymorphism, Genetic; D011379:Prognosis; D011859:Radiography; D012907:Smoking / Q000009:adverse effects* / Q000235:genetics
chemical_list: D015921:Dental Implants; D007375:Interleukin-1