Abstract

Zinc has antimicrobial activity and zinc salts including zinc chloride (ZnCl2) have been used for the control of oral malodor. In this study, we hypothesized that pyrrolidine dithiocarbamate (PDTC), a zinc ionophore, may enhance antimicrobial efficacy of ZnCl2. The bactericidal effectiveness of ZnCl2 alone (0.5-8 mM) or in combination with PDTC (1 or 10 μM) was evaluated by in vitro short (1 h) time-killing assays against Fusobacterium nucleatum and Porphyromonas gingivalis. Only a slight viability decrease was observed with ZnCl2 or PDTC alone after 1-h incubation. By contrast, combination of ZnCl2 and PDTC could achieve a more than 100-fold viability reduction compared with ZnCl2 or PDTC alone in F. nucleatum and P. gingivalis. Therefore, PDTC greatly enhanced the bactericidal activity of ZnCl2 against the oral malodor-producing bacteria. These results suggest that use of PDTC may be useful for enhancing bactericidal activity of antimalodor regimens of zinc salts.

• Keywords: oral malodor; zinc; pyrrolidine dithiocarbamate; bactericidal