ABSTRACT
Objective: To explore levels of salivary IgA, lysozyme, lactate dehydrogenase, alkaline phosphatase and total proteins in unstimulated (UWS) and stimulated (SWS) whole saliva of caries-free children. Methods: 94 caries-free children, aged from 42 to 54 months, were recruited from urban kindergartens in Beijing. 2 ml UWS and 2 ml SWS were collected from each child to measure salivary IgA, lysozyme, lactate dehydrogenase, alkaline phosphatase and total proteins. Results:1) There were no differences in salivary proteins between boys and girls in both UWS and SWS, except total proteins. In UWS, the concentration of total proteins in girls was lower than that in boys (P0.05). 2) The concentration of IgA in SWS was significantly lower than that in UWS (P0.05). Conclusion:In 3-to 4-year old children, the protein composition in stimulated whole saliva is different from that in unstimulated whole saliva, and it is also different between genders. Therefore, it is more reliable to measure salivary proteins in both UWS and SWS when studying saliva of children.