Antimicrobial Activity of Different Root Canal Filling Pastes Used in Deciduous Teeth

The purpose of this study was to evaluate in vitro the antimicrobial activity of materials used as root canal filling in deciduous teeth by direct exposure test. The materials tested were: Guedes-Pinto, CTZ, zinc oxide eugenol, Calen, L&C and MTA pastes. A microbial mixture was prepared with 1 mL each of pure suspension of the following microorganisms: Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Bacillus subtilis, Candida albicans. For the direct exposure test, sterilized paper points were contaminated with the microbial mixture suspension and placed in contact with the respective materials for 24, 48 and 72 hours. At these intervals, paper points were removed and immersed in 7 mL of Letheen broth, followed by incubation at 37 °C/48 hours. 100 µL of inoculum obtained from Letheen broth was transferred to 7 mL of BHI under identical incubation conditions. Microbial growth was evaluated by macroscopic examination of BHI broth turbidity. In conclusion, only the CTZ and MTA pastes showed antimicrobial activit