The influence of intraoral cryotherapy on postoperative pain and substance P in symptomatic apical periodontitis: randomized clinical study.

Cryotherapy is widely utilized in medicine, particularly for pain management. This randomized clinical trial aimed to assess the effect of intraoral cold pack application (cryotherapy) on postoperative pain (POP) and the level of Substance P (SP) in patients with symptomatic apical periodontitis (SAP). Enrolled patients were randomly assigned to either cryotherapy or control group. After adequate anesthesia, access cavity, and biomechanical preparation of the root canal system were completed, the first apical fluid (AF) sample (S1) was obtained. A custom-made intraoral ice-gel pack was applied for 30 min in the cryotherapy group, while no intervention was performed in the control group. The second AF sample (S2) was collected 30 min later in both groups. Patients were asked to complete the Visual Analogue Scale (VAS) questionnaire to assess their POP. Quantification of SP in AF samples was performed using the enzyme-linked immunosorbent assay (ELISA) test. Data were analyzed statistically, revealing a significant reduction in POP and SP levels in the cryotherapy group compared to the control group (P ≤ 0.05). Furthermore, a moderate positive correlation was observed between SP levels and POP (P ≤ 0.05). In conclusion, intraoral cryotherapy represents a simple and cost-effective option for controlling POP and reducing inflammation levels in patients with SAP.