The present study showed that a ZOE-based material has an antibacterial effect and that incorporating CH or COS may increase the antibacterial effect depending on the bacterial species. The total release of eugenol from the materials was stable for up to 18 weeks immersion in water. Eugenol therefore contributed to the antibacterial effect on all the material surfaces investigated. S. mutans exhibited the highest susceptibility to eugenol. The compressive strength of the modified materials was reduced but still met the requirements in ISO 3017.