The intra-oral variation of salivary ions

Objectives Dry mouth etiologies, which often present as a combination of hyposalivation and xerostomia, are difficult to differentiate. Employing a combination of a location-based approach in the oral cavity and salivary ion measurement may resolve this differential diagnostic gap. In this light, the aim of this cross-sectional study was to determine the concentrations of salivary sodium, potassium, chloride, phosphate, calcium, ammonium, nitrate, nitrite, fluoride, sulphate and magnesium at 7 intra-oral locations in healthy subjects ( N = 30). Methods First, sterile foam tipped applicators were selected as the most suitable tool to take saliva samples from these areas. Ion levels were analyzed using a capillary electrophoresis system. Results Almost every ion included showed a unique intra-oral distribution pattern across the selected regions. For example, the palate demonstrated the highest sodium concentration and in contrast, the floor of the mouth showed the lowest. The observed distribution patterns were consistent between individuals. Conclusions Local variations in salivary ion concentrations may be influenced by the positioning of the salivary glands and their associated ducts but could also relate to their function in the oral cavity. Clinical Relevance The results from our healthy controls can form a reference for future studies and potentially for diagnostic purposes in clinical contexts.