Use of x‐ray microanalysis to monitor diffusion of Zn from a cement into human dentin

Abstract

Energy dispersive x‐ray spectrometry (EDAX system), with scanning electron microscopy was used to detect diffusion of Zn from a source in human dentin and the system was tested for sensitivity and reproducibility. Sections of human teeth in which a ZnO‐eugenol cement had been placed in a cavity in the dentin in vivo were prepared and x‐ray microanalytical measurements carried out. We found that values of counts for Zn, Ca and P in the same field were linear up to a total counting time of 60 sec. We further found that reproducibility of values between repeat examinations of the same specimens on different days was excellent. The concentration of Zn in the dentin decreased exponentially with distance from source within the distance tested. We conclude that the system can be used to detect trace concentrations of Zn, and that accordingly the diffusion behavior of a variety of ions in dentin could be monitored.

Inhibition of human pulpal gelatinases (MMP‐2 and MMP‐9) by zinc oxide cements

“…With a 2‐mm thickness of dentine the concentration of eugenol decreased from 10 −2 m , in the aqueous phase beneath the ZOE, to 10 −4 in the zone adjacent to the pulp (31). The diffusion of zinc from ZOE cement into the surrounding dentin follows a similar pattern (28). Although the exact concentration of diffusible zinc that can reach the pulp was not determined, the diffusion of zinc is likely to be more efficient than eugenol, as the diffusion of substances through dentin is proportional to the size of the molecule (27).…”