Abstract
A mouth rinse containing calcium, phosphate, fluoride, urea and monofluorophosphate was used 12 times over 3 days by 15 young adults. The concentration of acid-extractable fluoride in 4-day-old plaque rose from 8.4 to 560 ng/mg dry weight. Plaque calcium increased from 4.1 to 42.5 μg/mg and phosphate from 3.9 to 22.7 μg/ mg. The ions are fixed in a form insoluble in saliva, probably as fluorhydroxyapatite, and thus are likely to have an extended caries-protective effect.