Evaluation of antimicrobial efficacy of various root canal filling materials used in primary teeth: a microbiological study.

The primary goal of endodontic treatment in primary teeth is to eliminate infection, and to retain the tooth in a functional state until their nornal exfoliation time without endangering the permanent dentition or the general health of the child. The complexity of the pulp canal system in primary teeth presents a discerning problem for chemo-mechanical preparation. One of the factors determining the success of endodontic treatment in infected primary teeth is the sealing material that should encompass among other factors a potent bactericidal effect and the capacity to resorb along with the roots of primary teeth. This study evaluated the antimicrobial effectiveness of 5 root canal filing materials and a negative control agent against 23 strains of bacteria isolated from infected root canals of primary molar teeth and 3 non standard bacterial strains using agar diffusion assay. The materials were Zinc oxide and Eugenol (ZOE), Zinc oxide-Eugenol and Formocresol (ZOE+FC), Calcium hydroxide and sterile water (CAOH+H2O), Zinc oxide and Camphorated phenol (ZO+CP), Calcium hydroxide and Iodoform (Metapex) and Vaseline (Control). All the materials except Vaseline showed varied antimicrobial activity against the test bacteria. The zones of inhibition were ranked into 4 inhibition categories based on the proportional distribution of the data. All the 26 bacterial isolates were classified under 4 groups based on Aerobic/Anaerobic and Gram positive/Gram negative. Statistical analysis was carried out to compare the antimicrobial effectiveness between materials tested with each of the bacterial groupings. ZOE+FC produced strong inhibtion against most bacteria when compared to ZOE, ZO+CP and CAOH+H2O. Metapex and Vaseline were found to be non inhibitory