The effect of temperature change on the sealing properties of temporary filling materials

Abstract The cavity-sealing properties of nine filling materials (eight temporary filling materials and amalgam) were tested at room temperature and also after ten cycles of temperature change from 60° C. to 4° C. The ability of a 2 per cent aqueous solution of aniline blue dye to penetrate the margins of cavities filled with each of the test filling materials was used as a means of comparing their cavity-sealing properties. The inability of the test filling material to maintain a leakproof seal of the cavity margins was evidenced by a blue discoloration of cotton fibers placed beneath the test filling. Under the conditions of testing at room temperature, the following materials showed consistent leakage: temporary stopping gutta-percha, base plate gutta-percha, two brands of zinc phosphate temporary cement, and two brands of zinc phosphate permanent cement. The materials that showed no leakage at room temperature were zinc oxide-eugenol cement, Cavit, and amalgam. Of the teeth similarly filled with each of the nine test filling materials and subjected to ten cycles of temperature change, those which showed leakage to the dye solution at room temperature also showed leakage when subjected to temperature changes. Although zinc oxide-eugenol cement did not show leakage at room temperature, it did show leakage in five out of ten teeth subjected to temperature changes. Of the temporary filling materials tested, only Cavit maintained a leakproof cavity seal both at room temperature and after repeated temperature changes.