Antimicrobial action of root canal filling pastes used in deciduous teeth

Abstract

Purpose: This study assessed the antimicrobial effectiveness of an iodoform-based paste (Guedes-Pinto Paste, GPP) and a paste modified by the addition of a 2% chlorhexidine gluconate gel (CHX) to replace the camphorated parachlorophenol component of the original GPP. Methods: The antimicrobial action was tested against the following microorganisms: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus oralis, Enterococcus faecalis, Escherichia coli and Bacillus subtilis. In the agar diffusion test, 18 Petri plates with 20 mL of BHIA were inoculated with 0.1 mL of the microbial suspensions. Paper disks were immersed in the experimental solutions for 1 min and were then placed over the BHIA surface in each agar plate. The plates were maintained for 1 h at room temperature and then incubated at 37ºC for 48 h. The diameters of the microbial inhibition halos were measured around the paper disks containing the substances. Data were analyzed using the Mann-Whitney U-test (α=0.05). Results: Antimicrobial action was observed for the GPP and CHX pastes, which presented absence of turbidity for almost all microorganisms. No statistically significant difference in the antimicrobial action was found between GPP and CHX. Conclusion: Both pastes present similar antimicrobial effectiveness against several microorganisms commonly found in endodontic infections in deciduous teeth.