The effect of point-of-use water conditioning systems on community fluoridated water.

The purpose of this investigation was to determine the effect of several point-of-use water conditioning systems on the fluoride concentration in community fluoridated water. Point-of-use water conditioning systems attach at the sink to provide the user with protection from certain water contaminants. A sampling apparatus was constructed to allow collection of water samples before and after conditioning. The apparatus connected the following types of point-of-use water conditioning systems: a faucet water filter, a cellulose fiber filter, an activated carbon filter, a reverse osmosis system, and a distillation unit. These samples were tested by an independent laboratory using colorimetric determination of fluoride concentration. All point-of-use water conditioning systems tested caused a statistically significant reduction in fluoride (P less than .001). Of particular note were reductions in fluoride concentration by the activated carbon filter (81%), the reverse osmosis system (84%), and the distillation unit (99%). These reductions are clinically significant, and necessitate supplementation for optimal fluoride intake. Patients using these water conditioning systems should be advised to have their water tested, and to consider fluoride supplementation to ensure adequate benefit from this caries prevention method.