Effect of Inflamed Pulp Tissue Extirpation on Levels of Inflammatory Neuropeptides in Human Saliva

Abstract

Aim: to measure and compare the salivary levels of substance P (SP), calcitonin gene-related peptide (CGRP), and neurokinin A (NKA) before and after inflamed pulp tissue extirpation. Also, the differences between pre- and postoperative visual analog scale (VAS) pain scores were evaluated.Methods: Twelve patients with irreversible pulpitis related to a mandibular molar tooth were enrolled in this study after fulfillment of the selection criteria. Patients rated their level of pre- and postoperative pain on a visual analog scale. Saliva samples were collected from each patient before and 5 days after the first endodontic treatment visit. All samples were analyzed using (ELISA) kits. The differences between the pre- and postoperative levels of SP, CGRP, and NKA were analyzed using the one-way ANOVA test while the differences between the pre- and postoperative VAS scores were evaluated using the paired t-test. Any correlation between levels of SP/CGRP/NKA and VAS pain scores was examined using the bivariate analysis.Results: There was a statistically significant difference between pre- and postoperative levels of SP and also between pre- and postoperative levels of CGRP. No significant difference was found between pre- and postoperative levels of NKA. Regarding VAS scores, the preoperative pain was significantly higher than postoperative pain. The VAS score of subjective pain was significantly correlated with levels of SP and CGRP but not NKA. Conclusions: SP and CGRP can be employed as beneficial determinants of the degree of pain in inflammatory pulpal diseases. NKA plays an insignificant role in neurogenic inflammation and pain.