Analysis of the association of IL1B (C+3954T) and IL1RN (intron 2) polymorphisms with dental implant loss in a Brazilian population

Background: Although dental implants have a high success rate, failures occur, in spite of adequate clinical conditions. Together with the observation that multiple implant losses occur in certain groups of individuals (clusterization phenomenon), this suggests that host response may influence implant failure. Little is known about the influence of genetic susceptibility on implant loss. Interleukin (IL)-1β and IL-1ra are believed to play a key role in the immune-inflammatory response, and polymorphisms IL1B (C+3954T) and IL1RN (intron 2) are shown to alter the coding proteins expression.
Objectives: The aim of this study was to investigate the association between dental implant loss and polymorphisms IL1B (+3954) and IL1RN (intron 2).
Material and methods: The study population ( n =266) was divided into Test group (T) – 90 subjects with implant loss, and Control group (C) – 176 subjects without any implant failure. Genotyping was performed by PCR-RFLP.
Results: The number of present teeth was observed to influence implant loss. No differences in genotype and allele frequencies between C and T were found for IL1B (+3954) and IL1RN (intron 2) polymorphisms. However, the analysis of the whole study population (control and test groups) showed that genotype 2/2 was significantly more frequent in individuals with multiple implant losses ( n =35) than in individuals that lost up to a single implant ( n =231) (OR: 3.07, IC: 1.13–8.34, P =0.027).
Conclusion: It was observed that number of teeth and edentulism were associated with implant loss. Genotype 2/2 of IL1RN polymorphism was significantly more frequent in patients who presented multiple losses, which suggests that the clusterization phenomenon has a genetic basis.