The Role of Salivary C-Reactive Protein in Systemic and Oral Disorders: A Systematic Review

Background: Blood sampling is expensive, time-consuming, invasive, and requires technical facilities, which can be replaced by more convenient samples such as saliva. C-reactive protein (CRP) is a widely used biomarker in the management of many disorders and plasma CRP (pCRP) is suggested to be replaced by salivary CRP (sCRP). This study aimed to systematically review all available literature on the sCRP levels in systemic and oral disorders and how sCRP and pCRP levels correlate among these patients and healthy individuals. Methods: In this systematic review, a PubMed, Embase, Scopus, and Google Scholar search was conducted on October-2021 to identify all research investigating sCRP levels in systemic and oral disorders. Results: A total of 130 publications were analyzed in the review. Most of the studies reported that sCRP and pCRP levels are correlated, and sCRP is a reliable alternative for pCRP level for the diagnosis and management of medical conditions. sCRP has been measured in many different medical and oral disorders and significantly correlated with disease activity in most cases. Conclusion: Salivary CRP is a good alternative for Plasma CRP levels in most cases.