Decontamination of the oral cavity. Effect of six local anti-microbial preparations in comparison to water and parafilm as controls.

Six preparations (four liquid and two solid) were tested in a double-blind crossover design for their anti-bacterial effect on aerobic and anaerobic bacteria in saliva of 12 volunteers. The four liquid preparations contained either tyrothricin, hexetidine, hydrogen peroxide or ethanol and were tested against a rinse with water as control. The two solid preparations, in the form of lozenges, contained tyrothricin in doses of 4 or 10 mg and were tested against parafilm. A single rinse with either tyrothricin or hexetidine resulted in a significant reduction of aerobic and anaerobic bacteria in saliva which lasted for the whole 1 h observation period and was considerably more effective than hydrogen peroxide or ethanol. Similar results were seen with the solid preparations. The lozenge containing 10 mg tyrothricin was the most effective and was the only formulation capable of reducing oral aerobic bacterial counts by a factor of approximately 100.