Prophylactic mineral enrichment of approximal dental plaque

Most research on the chemical modification of dental plaque has used material from buccal and lingual smooth surfaces of teeth--plaque that is readily accessible to treatment solutions. The aim of this study was to test, on the more sheltered approximal plaque, the effect of a mouthrinse previously found to be effective in raising calcium, phosphate, and fluoride concentrations in accessible plaque. Five young adults participated in a blind, cross-over trial to compare a Ca-P-MFP-urea test rinse and a NaCl placebo rinse. For 6 days, subjects rinsed twice per day after their normal toothbrushing, using 10 ml of rinse solution for 30 seconds and a fresh 10 ml for a further 30 seconds. A non-fluoride toothpaste was used and normal flossing was withheld. Plaque was collected before rinsing and again 16 hours after the final rinse from all approximal sites except those between the lower anterior teeth. Pre- and post-rinse calcium values were 291 +/- 100 and 511 +/- 107 nmol/mg protein (mean +/- SD) respectively for the test rinse, and 368 +/- 223 and 306 +/- 125 nmol/mg protein respectively for the placebo. Analysis of variance showed that the test rinse had a significant effect on plaque calcium but not on phosphate or fluoride. Mean calcium values of about 2,400 nmol/mg protein have been obtained previously in smooth-surface plaque after use of the test rinse. The reduced effect here is probably due to restricted access of the rinse solution.