Effect of Er, Cr: YSGG laser–activated final irrigation on gingival crevicular fluid RANKL/OPG levels

This study aims to investigate the effect of Er, Cr: YSGG laser activation of NaOCl during final irrigation on the level of RANKL/OPG in the gingival crevicular fluid of mandibular molars with periapical lesions at 1 and 3 months after root canal treatment. Thirty patients with periapical lesions in mandibular molars in the study. Root canal treatment was completed in two visits. Participants were randomly allocated into two groups (n = 15). In the experimental group, NaOCl was activated using an Er, Cr: YSGG laser, while in the control group no activation was performed during final irrigation. Gingival crevicular fluid samples were collected at baseline, one month, and three months after treatment, and stored at - 80 °C until analysis. RANKL and OPG concentrations were quantified by ELISA. Statistical comparisons were made using the Mann-Whitney U and Fisher's Exact tests. Laser activation of NaOCl did not produce a statistically significant difference in the RANKL/OPG ratio compared with the control group (p > 0.05). Within-group analysis indicated a non-significant reduction in the RANKL/OPG ratio at 3 months after treatment compared to pre-treatment levels in both groups (p > 0.05). Er, Cr: YSGG laser-activated NaOCl irrigation did not produce a statistically significant difference between groups after three months. However, the early decrease in the RANKL/OPG ratio observed in the laser group suggests that laser activation may influence early inflammatory responses associated with the healing process following root canal treatment. Er, Cr: YSGG laser activation may influence early inflammatory conditions following root canal treatment, without demonstrating a definitive advantage within the three-month follow-up period.Trial registration: This study was prospectively registered at ClinicalTrials.gov (Identifier NCT05478811, Date 08/01/2022).