Influence of Intracanal Cryotherapy on Inflammatory Mediators Expression using Different Irrigation Protocols: A Randomized Clinical Trial

ABSTRACTAim: To evaluate the effect of intra-canal cryotherapy on interleukin-1βand interleukin-10 expression in teeth with symptomatic apical periodontitis.Methodology: Forty-eight single rooted teeth in patients with symptomatic apical periodontitiswere randomly divided into 4 groups according to the irrigation protocol.Group I (control); 5% sodium hypochlorite at room temperature. Group II; 5% coldsodium hypochlorite (2-5°C). Group III; final rinse with 20 mL of 5% cold sodiumhypochlorite (2-5°C) for 5 minutes. Group IV; final rinse with 20 mL of cold saline (2-5°C) for 5 minutes. Paper point passing 2 mm beyond the apex was used to collect periapicalfluid before, immediately after mechanical instrumentation and after one week tocharacterize the mRNA expression of IL-1β and Il-10 using real-time polymerase chainreaction (PCR). Statistical analysis was performed using one-way ANOVA to comparebetween all groups. Results: Our results revealed statistically significant (at P≤ 0.05)down regulation of IL-1β gene expression levels in all groups after one week with nostatistically significant difference between the four groups and statistically significant(at P≤ 0.05) up regulation of IL-10 gene expression levels in all groups after one week.Conclusion: All the cryotherapy irrigation protocols showed lower levels of expressionof the pro-inflammatory mediators (interleukin-1β) and higher levels of expression ofthe anti-inflammatory mediator (interleukin-10) than the control group after one week.