Analysis of IL-1 polymorphisms and implant loss

Dental implants represent an important therapeutical modality for tooth replacement. Although the high success rate, failures occur, even in patients presenting appropriate clinical conditions. Together with the observation that multiple implant losses occur in certain groups of individuals, this fact suggests that host response may influence implant failure. However, little is known about the influence of genetic susceptibility on implant loss. Interleukin (IL)-1 beta 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 evidenced to alter the expression of the coding proteins. Objectives: The aim of this study was investigate the association between dental implant failure and the polymorphisms IL1B (+3954) and IL1RN (intron 2). Methods: The study population (n=266) was obtained from the patient pool treated in the Latin American Dental Research Institute (ILAPEO), and divided into: Test group (T) - 90 subjects with implant loss, and Control group (C) - 176 subjects without any implant failure. Patients' socioeconomic profile, general medical condition, hygiene parameters, number of teeth and periodontal status were analyzed. Genomic DNA from oral mucosa was amplified by polymerase chain reaction (PCR). Polymorphisms IL1B (+3954) and IL1RN (intron 2) were in Hardy-Weinberg equilibrium. Results: Regarding clinical aspects, number of present teeth was observed to influence implant failure. No differences in genotype distribution and allele frequencies between C and T groups were found for IL1B (+3954) and IL1RN (intron 2) polymorphisms. Conclusion: It was observed that clinical parameters, but not the study polymorphisms, were associated with implant loss.