The effect of topical application of chlorhexidine on the bacterial colonization of the teeth and gingiva.

Abstract

Six dental students participated in two experiments throughout which they ceased all active oral hygiene measures. In the first experiment a 2 per cent solution of chlorhexidine and in the second a placebo solution was applied topically each day to all teeth. Throughout both 15 day experiments the bacterial colonization of the attached gingiva, gingival margin and tooth surface was examined using impression preparations and a microcolony technique. Bacterial colonization of the tooth surface occurred rapidly using the placebo and a bacterial plaque accumulated at the gingival margin as described in previous no‐oral‐hygiene experiments. No bacterial colonization of the tooth surface was observed throughout the chlorhexidine experiment. The bacterial flora of the attached gingiva remained unaltered, but at the gingival margin an increase in the numbers of gram negative cocci and rods occurred between days 5 and 10. A tendency was noted for this flora to revert back to gram positive by the end of the experiment. It is concluded that the inhibition of plaque formation by chlorhexidine is primarily a result of its ability to interact with the organic or inorganic components of the tooth surface.