Microleakage of "surface-sealing" materials.

PURPOSE To test several dental materials for their sealing properties by subjecting restored teeth to thermal cycling. MATERIALS AND METHODS Ten teeth per group were assigned at random to six experimental and six control groups. In the experimental groups a resin composite was surface-sealed with IRM, glass ionomer, amalgam, dentin bonding agent and resin composite, experimental hybrid cement, or zinc oxide and eugenol. These six surface-seal materials were placed in bulk in the control group. After cavity preparation, restoration, cut back and application of the surface-seal material, the teeth were subjected to thermal cycling, imbedded and sectioned. A score of 0-3 was given to the amount of dye leakage observed. RESULTS Zinc oxide and eugenol demonstrated the most leakage, whereas the resin composite system TPH had the least. The results of this in vitro study render the recommendation of zinc oxide and eugenol as a surface-seal material questionable.