Saliva is frequently used as a diagnostic fluid and several collection devices have been developed.
Objective: The aim of the present study was to investigate the validity and reliability of two types of Salivette collection kits (non-covered cotton roll and polypropylene covered polyether roll) relative to conventional collection of saliva using paraffin wax chewing stimulation.
Materials and methods: Whole saliva samples were collected from 16 healthy volunteers. Following a cross-over design saliva was collected in a standardized way. The flow rate was determined and saliva samples were analyzed for pH, buffer capacity, electrolytes and protein/glycoprotein content.
Results: We find that Salivette methods do not allow evaluation of flow rate. pH was unaffected but buffer capacity was lower in Salivette collected than in paraffin wax-stimulated saliva. The non-covered cotton rolls reduced the content of Na+, K+, Cl-, as well as glycoprotein markers (hexosamines, fucose, sialic acid), lysozyme, lactoferrin, salivary- and myeloperoxidase but increased the concentrations of Ca2+, PO4(3)- and SCN-. Polypropylene covered polyether rolls affected saliva composition less than the non-covered cotton rolls. Thus, SCN- and sIgA concentrations were higher and lysozyme activity lower in the former (covered roll) saliva than in paraffin wax saliva. The reliability of the Salivette kits was good.
Conclusion: We conclude that the Salivette method generates data significantly different from conventional paraffin wax-stimulated saliva such as buffer capacity and several electrolytes and organic components. Care should be taken in interpreting the results when such methods are employed.