Reduction of supragingival plaque accumulations in institutionalized Down's syndrome patients by periodic treatment with topical kanamycin.

A small group of institutionalized Down’s syndrome patients were treated with topical kanamycin sulphate paste, once or twice a day for 3-5 days, every fifth week over a 52-week-period. The teeth were not brushed during this 52-week-period. The wet weight of the supragingival plaque in the kanamycin group was significantly reduced when compared to the supragingival plaque formed in the group receiving a placebo paste. The gingivitis score of the kanamycin group did not deteriorate during the period of antibiotic administration despite the absence of oral hygiene procedures. No increase in kanamycin-resistant bacteria or yeasts were detected in plaque or tongue samples during the period of kanamycin treatment.