Evaluation of the antimicrobial effects of sodium benzoate and dichlorobenzyl alcohol against dental plaque microorganisms: An in vitro study

Abstract

Østergaard E. Evaluation of the antimicrobial effects of sodium benzoate and dichlorobenzyl alcohol against dental plaque microorganisms. An in vitro study. Acta Odontol Scand 1994;52:335–345. Oslo. ISSN 0001-6357.

Evaluation of antimicrobial agents is based on in vivo and in vitro studies. The minimum inhibitory concentrations (MICs) of sodium benzoate and dichlorobenzyl alcohol to 115 strains of plaque microorganisms were determined by a broth-dilution method. Sodium benzoate did not inhibit growth of any gram-positive cocci (MIC > 106,590 µM). MICs for Porphyromonas gingivalis and two strains of Treponema socranskii were 26,650 µM. The MIC of dichlorobenzyl alcohol to the reference strain of Actinobacillus actinomycetemcomitans was 723 µM and to P. gingivalis, two strains of T. socranskii, and Candida albicans 1,446µM. MICs for other organisms were 2,892 to 5,784 µM. Saliva samples from 10 volunteers, collected at various times after toothbrushing with a dentifrice containing 10% sodium benzoate and 0.3% dichlorobenzyl alcohol, were analyzed gas-chromatographically. Immediately after toothbrushing mean levels of sodium benzoate and dichlorobenzyl alcohol were 372,626 µM and 7,529 µM, respectively. After 5 min mean levels were 38,700 µM and 734 µM. In conclusion, the concentrations of both antimicrobials dropped rapidly during the first 30 min, but for 5–10 min they were high enough to inhibit growth of potential periodontal pathogens.

Key Words:

• Dentifrice
• plaque microorganisms
• saliva
• toothbrushing