EVALUATION OF THE ANTIMICROBIAL EFFECTS OF SODIUM BENZOATE AND DICHLOROBENZYL ALCOHOL AGAINST DENTAL PLAQUE MICROORGANISMS - AN IN-VITRO STUDY

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