Inhibition of malodorous gas formation by oral bacteria with cetylpyridinium and zinc chloride.

Objective: The antimicrobial efficacy of zinc- (ZnCl) and cetylpyridinium-chloride (CPC) and their inhibition capacity on volatile sulfur compound (VSC) production by oral bacterial strains were investigated.

Design: Minimum inhibitory concentrations (MIC) and growth curves were determined for ZnCl, CPC, and CPC with ZnCl solutions against eight oral microorganisms (Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola, Tannerella forsythia, Staphylococcus aureus and Streptococcus mutans) known to be involved in the pathophysiology of both halitosis and periodontal disease. Gas chromatography was applied to measure VSCs (HS, CHSH, (CH)S) production levels of each strains following exposure to the solutions.

Results: ZnCl and CPC effectively inhibited growth of all eight strains. ZnCl was generally more effective than CPC in suppressing bacterial growth excluding A. actinomycetemcomitans, P. intermedia, and T. forsythia. Synergism between CPC and ZnCl was shown in A. actinomycetemcomitans. The MIC for CPC was significantly lower than ZnCl. VSC production was detected in five bacterial strains (A. actinomycetemcomitans, F. nucleatum, P. gingivalis, T. denticola, and T. forsythia). Each bacterial strain showed unique VSCs production profiles. HS was produced by F. nucleatum, P. gingivalis, and T. denticola, CHSH by all five strains and (CH)S by A. actinomycetemcomitans, F. nucleatum, P. gingivalis, and T. denticola. Production of CHSH, the most malodorous component among the three major VSCs from mouth air was evident in F. nucleatum and T. forsythia.

Conclusion: Both ZnCl and CPC effectively inhibit bacterial growth causative of halitosis and periodontal disease, resulting in a direct decrease of bacterial VSCs production.