IN VITRO EXPERIMENTS ON THE BACTERICIDAL EFFECT OF ZINC OXIDE EUGENOL CEMENT ON BACTERIA-CONTAINING DENTIN

¹ Research Department, International Serum Institute, London, Mill Hill, England

1. Sterile slices of decalcified dentin, 1 mm. thick, were inoculated with 4 pure strains of Staphyl. pyogenes aureus, Latobacillus acidophilus odontolyt., E. coli, and Candida albicans and exposed to a zinc oxide eugenol cement in vitro, for 1, 3, 6, 24, 32, and 48 hours, respectively.

2. Gram-negative E. coli proved to be the most sensitive organism throughout the entire series.

3. The cement exerted a bacteriostatic and bactericidal effect on the 3 other strains.

4. After close contact with the cement for 24 and 48 hours, all inoculated slices were sterile.

5. Under similar conditions, natural decay obtained from extracted carious teeth was resistant and in no single case was the decayed dentin sterilized.

6. It is, therefore, intended to reinforce this cement in such a way that it will disinfect, if not sterilize, carious tissue in vitro as well as in vivo without impairing the vitality of the pulp.