Antimicrobial Effect of Cinnamaldehyde and <i>α</i> ‐Terpineol on Endodontic Biofilms of <i>Candida albicans</i> and <i>Enterococcus faecalis</i>

<b>Objectives:</b> The objective was to assess the antimicrobial effect of cinnamaldehyde and <i>α</i>-terpineol on mono-species and dual-species biofilms involved in endodontic infection. <b>Materials and Methods:</b> The phytoconstituents were used at a concentration of 10 mg/mL. The biofilms of <i>Candida albicans</i> (ATCC 90028) and <i>Enterococcus faecalis</i> (ATCC 29212) were developed for 7 days and evaluated by metabolic capacity analysis using MTT, cell viability analysis by CFU/mL, and phospholipase activity. The RPMI 1640 medium was used as the negative control and sodium hypochlorite 2.5% and chlorhexidine 2% were used as positive controls. Data were analyzed by a Kruskal-Wallis test and stepwise with adjusted Bonferroni for nonnormal data and an ANOVA one-way test followed by Tukey's post hoc test for normal data (<i>α</i> = 5%). <b>Results:</b> The cellular metabolism of the <i>C. albicans</i> and <i>E. faecalis</i> mono-species biofilms was reduced by cinnamaldehyde and <i>α</i>-terpineol (<i>p</i> < 0.05). For dual-species biofilm, only <i>α</i>-terpineol showed differences compared to the negative control (<i>p</i> < 0.05). The phytoconstituents showed an inhibitory effect on cell viability (CFU/mL) and phospholipase activity of biofilms, having an activity similar to sodium hypochlorite (<i>p</i> > 0.05). <b>Conclusions:</b> The phytoconstituents cinnamaldehyde and <i>α</i>-terpineol, at a concentration of 10 mg/mL, had an inhibitory effect on mono-species and dual-species biofilms of <i>E. faecalis</i> and <i>C. albicans</i>.