The aim of this study was to investigate the influence of acute stress on salivary fluoride bioavailability. Acute psychological stress was induced using a standardized model of public speaking. The saliva of male subjects was collected before and after the public speaking task and immediately, 10, 30, and 120 minutes after tooth brushing according to the Bass method with a dentifrice containing amine fluoride (AmF) or oral hygiene tablets containing sodium fluoride (NaF). Subjective psychological responses to public speaking were evaluated using the State-Trait Anxiety Inventory (STAI). Saliva cortisol levels were analyzed as an objective stress marker. The saliva secretion rate was measured both before and after public speaking. Saliva fluoride content was measured. Group comparisons were calculated using a univariate analysis of variance (ANOVA). In all analyses, the alpha-level was set at 0.05. Public speaking significantly increased state anxiety (p<0.001) and salivary cortisol concentrations (p<0.001). Acute stress did not influence salivary secretion rates. In the AmF group, stressed individuals exhibited statistically significant (p=0.044) lower fluoride concentration in saliva compared with the nonstressed subjects Acute psychological stress reactions do not cause hyposalivation but decrease fluoride bioavailability after using a dentifrice containing AmF. Fluoride bioavailability during acute stress is dependent on fluoride formulation.