Aim To assess the efficacy of photobiomodulation in reducing post‐operative symptoms and use of analgesics in teeth with asymptomatic apical periodontitis treated with foraminal enlargement in a single visit. Methodology This prospective double‐blind, controlled, superiority, randomized clinical trial enrolled 70 patients requiring root canal treatment of one single‐rooted tooth with asymptomatic apical periodontitis. The participants were randomized into one of the following two groups: 35 patients in the control group (C.G) – root canal treatment with foraminal enlargement, without any additional treatment and 35 patients in the photobiomodulation group (PBM.G) – root canal treatment with foraminal enlargement associated with photobiomodulation (antimicrobial photodynamic therapy and low‐level laser therapy). The outcome variables were post‐operative pain, tenderness, oedema and the use of analgesics. Pain intensity was measured using a visual analogue scale (recorded every day for 7 days, then the 14th and 30th days after root canal treatment). Facial oedema was assessed subjectively by two independent evaluators using photographs taken by one of the researchers at 48 h, 72 h and 7 days after the procedures. Data were tabulated and analysed using the Mann–Whitney U, Chi‐Square, Fisher`s Exact, Student T and Ordinal Logistic Regression by Generalized Estimating Equations tests in SPSS software. Results There were no significant differences in post‐operative pain and tenderness between the groups at any observation period (p > .05). Photobiomodulation (beta = −0.77 / p = .01), time (beta = −0.23 / p < .01), and male gender (beta = −1.20 / p < .01) were associated with decreased post‐operative pain. Only time (beta: −0.10; p < .01) and male gender (beta: −1.04; p < .01) were associated with decreased tenderness. For oedema and use of analgesics, there was no difference between the groups (p > .05). Conclusions Photobiomodulation had no significant effect on post‐operative pain, tenderness, oedema and the use of analgesics after root canal treatment with foraminal enlargement, in single‐rooted teeth treated in a single visit. Register of Clinical Trials: NCT03704857. Research Ethics Committee: no 2.353.996 / CAAE 74185417.9.0000.5626.

Root canals near the maxillary sinus with endodontic treatment and apical periodontitis may exhibit positive cultures for filamentous fungi. Interested professionals should be alert, because these microorganisms have pathogenic characteristics that can cause disease of odontogenic origin in the maxillary sinus.

AimThis study aimed to investigate whether single‐nucleotide polymorphisms (SNPs) in the genes encoding 5‐HTR2A (5‐Hydroxytryptamine (serotonin) receptor 2A) and MTNR1A (melatonin receptor 1A) may contribute to postoperative pain perception after root canal treatment. We hypothesised that SNPs in HTR2A and MTNR1A genes were associated with postoperative pain after root canal treatment.MethodologyThis genetic cohort study enrolled patients with single‐rooted teeth diagnosed with pulp necrosis and asymptomatic apical periodontitis before root canal treatment. Root canal treatment was performed in one session using a standardized protocol. Postoperative pain and tenderness were assessed using a visual analogue scale (recorded every day for 7 days and on the 14th and 30th days after root canal treatment). Genomic DNA was extracted from saliva and used to genotype the SNPs in HTR2A (rs4941573 and rs6313) and MTNR1A (rs6553010, rs6847693 and rs13140012) using real‐time polymerase chain reaction. Genotypes were compared using univariate and multivariate Poisson regression with generalized estimating equations (p < .05).ResultsIn total, 108 patients were enrolled in this study. The SNPs rs6553010 (MTNR1A), rs4941573 and rs6313 (HTR2A) were associated with an increased risk of developing pain after root canal treatment (p < .05).ConclusionsThis study suggests that SNPs in HTR2A and MTNR1A influence pain response after root canal treatment.