Effects on pulp and dentin of iontophoresis of sodium fluoride on exposed roots in dogs.

Experiments were performed on young permanent teeth in which there was demonstrable active dentin formation. Following surgical exposure of roots and removal of cementum with scalers, 1 percent sodium fluoride in aqueous solution was applied either topically or with direct-current iontophoresis. Two levels of current, therapeutic or five times therapeutic, were used. Observation periods were 7 and 80 days. There were no demonstrable histologic or ultrastructural alterations of the underlying pulp; nor was there a resultant change in the rate of dentin formation. While exposure of root surface dentin alone (negative control) produced no alterations, grinding the surface (positive control) caused noticeable changes in dentin, odontoblasts, and pulp.