Gingival Crevicular Fluid Levels of Neurokinin A and Substance P in Patients with Symptomatic Irreversible Pulpitis: A Systematic Review and Meta-Analysis

AIMS AND OBJECTIVES: The levels of neuropeptides neurokinin A (NKA) and substance P (SP) in the gingival crevicular fluid of patients with symptomatic irreversible pulpitis (SIP) were evaluated using a comprehensive review and meta-analysis. MATERIALS AND METHODS: The data bases of Pubmed, Scopus, EBSCOhost, Science Direct, Proquest and Cochrane library databases were thoroughly searched. The quality of the study was evaluated using the Joanna Briggs Criteria. Twenty four studies were listed following a thorough search of full texts, abstracts, and removal of duplicates. Only two of these papers were eligible for inclusion in the meta-analysis. Since the results obtained were in mean and standard deviation, the levels of neuropeptides in the test and control groups were examined using the meta-analysis. RESULTS: When compared with healthy teeth, NKA was not significantly elevated in GCF of individuals with SIP (P = 0.06; odd ratio = 1.34 [−0.05 to 2.74] at 95% confidence interval [CI]). Additionally, there was no evidence of an association between SP and SIP (P = 0.08; odds ratio = 0.84 [−0.10 to 1.77] at 95% CI). CONCLUSION: This systematic research demonstrated that in individuals with SIP, NKA, and SP are not substantially linked. However, the lack of study in this area makes it evident that additional research is needed, particularly in relation to pulpal disorders and NKA.