Investigation of genetic polymorphisms in interleukins associated with pain after root canal treatment

To evaluate the association between genetic polymorphisms in interleukin one alpha (IL-1A), interleukin 10 (IL-10), and interleukin 1 receptor antagonist (IL-1RN) and pain after root canal treatment. This study included 108 participants with single-rooted teeth, single canal, and necrotic pulp associated with asymptomatic apical periodontitis, who underwent endodontic treatment in a single session. Pain and tenderness were assessed using a visual analog scale on the 1st, 2nd, 3rd, 4th, 5th, 6th, 7th, 14th, and 30th days after treatment. Genomic DNA was extracted from the saliva and used to genotype genetic polymorphisms in IL-1A (rs17561 and rs1304037), IL-10 (rs1800871), and IL-1RN (rs9005) using real-time PCR. The distribution of patients was assessed using univariate and multivariate Poisson regressions with generalized estimating equations (GEE). IL-1RN genetic polymorphism (rs9005) was associated with pain in the codominant (p = 0.023) and recessive (p = 0.044) models. There were no significant differences in tenderness between IL-1RN (rs9005), IL-1A (rs17561 and rs1304037), IL-10 (rs1800871), and tenderness (p > 0.05). The genetic polymorphism rs9005 in IL-1RN may influence pain after root canal treatment. Understanding the genetic basis of pain after endodontic treatment will advance its prevention and management.