MEASUREMENT OF THE ELECTRIC CONDUCTIVITY OF DENTAL CEMENT

III. EFFECT OF INCREASED CONTACT AREA AND THICKNESS; VALUES FOR RESIN, CALCIUM HYDROXIDE, ZINC OXIDE-EUGENOL

¹ Department of Dental Materials, Indiana University School of Dentistry, Indianapolis, Ind.

Increasing the contact area or the thickness of the cement does not appreciably alter the electric conductivity of zinc phosphate cement when the margins are exposed to saline solution.

The insulating abilities of various materials against electric energy have been investigated under both dry and wet conditions. When maintained dry, all, except calcium hydroxide, are adequate insulators. Acrylic resin and zinc oxide-eugenol paste continued to be effective insulators when exposed to saline solution, while calcium hydroxide and zinc phosphate cement are poor insulators under the wet conditions. Several types of experimental cells substantiated these observations.

The clinical significance of these data cannot be predicted until the in vivo tests now in progress are completed.