Salivary Biomarkers in Toxicology: An Update Narrative

Saliva is a complex biofluid, but also a magical biofluid, because it is a mirror of both oral and general health. Multiple general pathologies (of endogenous or exogenous cause) have an effect and expression on the structures of the oral cavity, but also in the excreted biofluids. Oral biofluid is available to practitioners to collect and then evaluate, but not without some challenges related to it: what type of saliva/oral biofluid was collected (stimulated versus unstimulated), at what time of day, what is the relationship with oral hygiene (collected immediately after teeth brushing or at a distance), if there are inflammatory processes in the oral cavity, or what is the salivary flow rate and if it is influenced by certain pathologies or drugs administered. The rate of excretion/diffusion of various compounds (which are intended to be used as salivary biomarkers for detection in toxicology) should also be considered in relation to plasma concentrations and renal excretion.