Method: A hundred-twenty human single-rooted teeth were contaminated with E. coli, E. faecalis and C.albicans for 28 days. The specimens were randomly divided into 5 groups (n=24) according to irrigant used in the instrumentation: G1) 12% propolis glycolic extract; G2) 20% Salvia officinalis glycolic extract; G3) 20% Arctium lappa glycolic extract, G4) 2% chlorhexidine; G5) pyrogen-free physiologic solution (control). Each group (n=24) was subdivided into 2 (n=12) according to intracanal medicaments: A) burdock with Ca(OH)2; B) Ca(OH)2 with physiologic solution. The root canal collections were performed after 28 days of contamination, after instrumentation, after 14 days of intracanal medicament and 7 days after medicament removal. The microbiological samples were plated in culture media and incubated (37ºC) for 48 hours. Limulus amebocyte lysate assay was used to quantify endotoxins. The results were submitted to ANOVA and Tukey’s test (5%).
Result: The groups G1 (propolis) and G4 (chlorhexidine) promoted elimination of E. faecalis, C. albicans and E. coli after instrumentation, being statistically different from G2 and G5 (control) (p<0.05). The group G3 (burdock) eliminated only C. albicans and E. coli. The group G2 (Salvia officinalis) promoted reduction, but not elimination, of microorganisms compare to control (p<0.05). All groups showed high levels of endotoxin after instrumentation (p>0.05), however, there was significant reduction of endotoxin after intracanal medications (subgroups A and B, p>0.05).
Conclusion: The propolis extract was the most effective against E. faecalis, C. albicans and E. coli and only the intracanal medications were able to neutralize endotoxins in root canals.
Keywords: Antimicrobials, Endodontics, Infection, Microbiology and Teeth