Effect of Ambient Water on Strength of Temporary Cements

Abstract

This study examined the effect of water on the mechanical strengths of temporary cements. Commercially available temporary cements (polycarboxylate cement, paste-mix type cement with and without eugenol and powder-liquid type zinc oxide-eugenol cement, two products of each type) were used. An hour after the start of mixing, a cement specimen was kept in either deionized water, a moist atmosphere, or air at 37℃, for up to 672 hours. The compressive strength and diametral tensile strength of each cement were determined. Polycarboxylate cements kept in air were significantly stronger with time than those in other conditions. Changes in strength of the eugenol-containing cements varied among the products tested. Paste-mix cement without eugenol did not show significant changes in strength with time in all the conditions tested. Difference in the dispensing type of cement, such as powder-liquid or paste-mix, is a factor affecting the sensitivity of cement to water.