RESUMO
AIM: To investigate whether single nucleotide polymorphisms (SNPs) within the interleukin-1 gene cluster (IL1) are associated with the occurrence and severity of inflammatory external root resorption (IERR) after replantation of avulsed permanent teeth. METHODOLOGY: Indexes of IERR were radiographically assessed in 182 mature replanted permanent teeth from 146 patients at the onset of endodontic therapy. DNA was extracted from buccal mucosa cells and genotyped using TaqMan probes-based assays for the SNPs IL1A -889C/T (rs 180058), IL1B +3954C/T (rs1143634) and IL1RN +2018C/T (rs419598). Teeth were grouped into two categories: IERR absent to mild (indexes ≤ 4) and moderate to severe IERR (indexes > 4). Genetic variations in the IL1 gene cluster were tested for their effect on the occurrence and extension of IERR using the GEE model (generalized estimation equation). Patient's age at the moment of injury, timing of pulpectomy, extra-alveolar period and storage condition of the avulsed teeth was included as possible confounders. RESULTS: No association was found between SNPs IL1A -889C/T, IL1B +3954C/T (rs1143634) and IL1RN +2018C/T (rs419598) and IERR indexes. Timing of pulpectomy (OR 3.5 IC 95% 2.0-6.2 P < 0.001) and patient's age at the moment of trauma (OR 0.29 IC 95% 0.12-0.67 P = 0.004) significantly affected the risk of developing severe IERR. CONCLUSIONS: While timing of pulpectomy and patient's age at the moment of trauma were confirmed as important risk factors, SNPs within the IL1 gene cluster did not affect the susceptibility for IERR after replantation of permanent teeth.