Objectives: The endodontic therapy of primary teeth aims to preserve the dentition in healthy conditions. A great number of irrigant solutions are use during endodontic treatment to obtain effective clean and desinfective roots canals. It was evaluated the effects of sodium hypochloride 0.5%, 2.5% and 5%, chlorhexidine gluconate 0.2% and 2%, hydrogen peroxide 3%, EDTA 17%, citric acid 6%, 10% and 15%, and tergentol 28% against deciduous root canals microorganisms, like as:
S. aureus, E. coli, S. epidermidis, L. casei, E. faecalis, C. albicans, C. tropicalis, C. parapsilosis and
C. glabrata. Methods: The antimicrobial activity of the solutions was evaluated by agar diffusion test with Brain heart infusion medium culture. It was used 10
6cell/mL like as standard inoculum for each microorganism. After incubation for 24 hours at 37
oC, the inhibition growth zone had been measured in millimeters. Results: All microorganisms used were sensible to least four irrigant solutions. The yeasts were the most sensible for the solutions tested. Although the tergentol and citric acid, in all concentrations, did not show any influence on the different species of
Candida growth, moreover the hydrogen peroxide 3% had only inhibited
C. tropicalis growth. The bacteria were more resistant to the irrigant solutions, principally the
S. epidermidis that was sensible to four of the eleven tested solutions (sodium hypochloride 0.5%, chlorhexidine gluconate 0.2% and 2%, and EDTA 17%). Citric acid 6% and tergentol 28% did not exhibited antimicrobial activity on fungal and bacterial growths. Conclusions: The results suggest that none of the solutions can be used perfectly as unique irrigant during primary teeth endodontic therapy. Therefore, the use of combined solutions as endodontic irrigant may increase the antimicrobial activity against root microorganisms, however the biocompatibility of these solution combinations against host cells must be accurate investigated.