Supplementation of domestic sugar (sucrose) with fluoride. Effects on experimental dental caries, plaque pH, and fluoride levels in plaque and enamel.

The minimum amount of fluoride which, when added to sucrose, will reduce caries in an intra-oral test was determined. Removable lower-arch appliances were worn by three adult subjects for 1 week, during which time plaque-covered enamel on one side was immersed in a 10 percent sucrose solution containing fluoride for 10 minutes four times per day. The effect of sucrose alone (control) was similarly determined on the other side of the appliance. Concentrations of 2 and 5 ppm F in sucrose solutions (20 and 50 ppm F dry weight) produced highly significant reductions in experimental caries of 43 and 44 percent respectively. A reduction in enamel dissolution due to re-precipitation of fluoride-rich apatite is probably largely responsible for the anti-caries effect. However, decreased plaque acid production may also play a role since the addition of 1 ppm F to 5 percent sugar reduced the plaque pH drop in artificial mouth experiments. Our results substantiate previous reports that fluoridation of sucrose to a level of 20 to 50 ppm F dry weight has potential benefits in caries prevention and may be useful when the F intake is otherwise low.