Salivary biomass assessed by bioluminescence ATP assay related to (bacterial and somatic) cell counts

The present work aimed (1) to evaluate ATP content in saliva by the biolumi nescent luciferin-luciferase method, (2) to evaluate the relationships betw een ATP content, bacterial count and epithelial cell numbers in saliva, (3) to study the effect of two different antiseptics (peroxidase system produc ing hypothiocyanite and chlorhexidine) on the salivary biomass. In 45 young adults, the salivary ATP content ranged from 8 to 1515 nM. Salivary ATP co ntent was significantly and directly correlated to bacterial count and epit helial cell numbers (Spearman-Rank correlation, P less than or equal to 0.0 01). Regression analysis allowed the inference of a mean epithelial cell an d bacterial ATP content of 152.7 fg and 8.3 fg pel. cell, respectively. The salivary ATP content decreased significantly to 38.8 +/- 12.3 per cent (me an +/- SEM, N = 6) of its initial value after a 30-min incubation in the pr esence of a peroxidase system producing hypothiocyanite (OSCN-). Chlorhexid ine (CHX) reduced salivary ATP content to 52.0 +/- 16.7 per cent. OSCN- did not affect the transformed logarithm of bacterial count but CHX reduced it from 7.02 +/- 0.26 to 0.52 +/- 0.33. No effect of OSCN- was seen on the ra tio of epithelial cell viability while CHX reduced it from 46.7 +/- 5.1 to 3.9 +/- 1.1 per cent. It is concluded that the combination of the evaluatio ns of the ATP content and cell numbers in saliva can provide reliable data about the effects of oral antiseptics on salivary biomass. Copyright (C) 20 00 John Wiley & Sons, Ltd.