The distribution of metallic constituents in dentin subjected to iontophoresis.

The concentration gradient and distribution of a metallic constituent in dentin which has been subjected to iontophoresis, using a water solution of silver diamine hydroxide and zinc chloride, were analyzed by means of EPMA as a basic study for pulp capping or cavity lining. Line scanning analyses parallel to the tooth axis showed that the transportation distance of metallic ions depends strongly on potential, period of iontophoresis and structural differences in dentin. Although metallic silver or zinc was found in the dentinal tubules, there was one case in which no metal was observed. The change in the distribution can be described as power function.