Interindividual differences in degradation of sodium monofluorophosphate by saliva in relation to oral health status

The enzymatic degradation of sodium monofluorophosphate by whole saliva in patients with differing oral health status was compared. Ten patients each with good or poor oral health were selected. Assessment of oral health status included indices of the amount of dental plaque, caries experience and counts of Streptococcus mutans and lactobacilli. Whole-saliva samples were collected under standardized conditions and monofluorophosphatase (MFPase) activity was measured in 2-ml saliva samples during 2 h of incubation at 37°C with 1 ml of monofluorophosphate solution (equivalent 31.5 mmol/1 F−). MFPase activity was found in all the saliva samples. The values ranged from 0.6 to 17.8 nmol F−/ml saliva per min. High MFPase activities correlated well with large amounts of plaque, with the D component of the DMFT index and with high counts of salivary S. mutans and lactobacilli. The results show a wide range of MFPase activity in individuals and a statistically significant correlation (p < 0.05) between high MFPase activity and poor oral health status.