An Exploratory Case-Control Study on the Impact of IL-1 Gene Polymorphisms on Early Implant Failure

Background: The association between IL-1 gene polymorphisms and peri-implantitis has been well documented. However, data on the association with early implant failure are scarce. Purpose: The objective of this case-control study was to explore the impact of IL-1A (-889), IL-1B (-511), and IL-1B (+3,954) gene polymorphisms on early implant failure in Caucasians. Materials and Methods: Between September 2004 and August 2007, 461 patients were treated with dental implants at the University Hospital in Ghent, Belgium. Fourteen subjects of this patient group who had experienced one or more early implant failures (within 6 months from implant installation) were recruited as "cases." Fourteen "controls," matched in terms of age, gender, and smoking habits, with only surviving implants, were selected from the same patient group. Allele and genotype analysis was performed on the basis of a blood sample by Sanger sequencing of polymerase chain reaction products containing the IL-1A (-889), IL-1B (-511), and IL-1B (+3,954) gene polymorphisms. Results: A significant impact of the IL-1A (-889) T allele (p=.039) and the IL-1B (+3,954) T allele (p=.003) on early implant failure was demonstrated (odds ratios=3.9 and 15.0, respectively). In addition, the genotypic distribution differed significantly between cases and controls for IL-1B (+3,954) (p=.015). Conclusions: The IL-1B (+3,954) gene polymorphism seems to affect osseointegration. Additional case-control studies in larger patient groups are needed to confirm this observation.