The variation of salivary peroxidase activities in persons of different oral health.

18 subjects (10 males, 8 females) with considerable differences in oral health conditions were examined regarding the peroxidase activity of oral fluid samples. Subjects with high caries prevalence and/or severe gingivitis displayed a significantly higher peroxidase activity than control subjects. Chromatographic experiments revealed that the increased activity was caused by salivary lactoperoxidase. This elevated activity does not, however, necessarily lead to better oral health because the antibacterial activity of lactoperoxidase also depends on the concentrations of thiocyanate ions and hydrogen peroxide. Hence the specific activity of lactoperoxidase, determined in vitro, is not as such as adequate measure of its antibacterial efficacy.