Eugenol: liberation from dental materials and effect on human diploid fibroblast cells

The amount of eugenol (4-allyl-2-methoxyphenol) released from four different dental materials immersed in phosphate buffer was measured by gas liquid chromatography. Maximal release of eugenol from zinc oxide-eugenol cement (ZOE) and IRM was attained within 5 h and corresponded to 5% and 4%, respectively, of the total amount of eugenol in each material. Both the rates and total amounts of eugenol released from Nobetec and Opotow were lower than for ZOE and IRM. Eugenol (0.67 mM) applied to growing cultures of human diploid fibroblasts reduced the number of cells recovered to a value which was 4% of that found for control cultures which grew to form monolayers. Confluent monolayers of 3H-uridine labeled cell cultures which were incubated for 1 h in the presence of 4 mM eugenol lost approximately 100% of this cytoplasmic label, indicating total cell death.