Calcium Pre-Rinse Greatly Increases Overnight Salivary Fluoride after a 228 ppm Fluoride Rinse

<i>Background:</i> Large increases in salivary fluoride were reported 1 h after a calcium pre-rinse/NaF rinse. <i>Aims:</i> This study examined the persistence of these increases. <i>Methods:</i> 12 subjects rinsed in the evening with water, with a 228 µg/g (ppm) F rinse or with 150 mmol/l calcium lactate followed by a 228 µg/g F rinse. In a second experiment these same patients rinsed with a 912 µg/g F rinse. Saliva samples were obtained the morning after rinsing, centrifuged and the supernatants analyzed. <i>Results:</i> The Ca pre-rinse/228 µg/g F rinse induced an increase in overnight salivary F over the 912 µg/g F rinse (≈2.5 times) and a statistically significant increase over the 228 µg/g F rinse (≈5.5 times). <i>Conclusions: </i>The results suggest that a Ca pretreatment may increase the cariostatic effect of topical F agents.