In vivo effects of zinc and chlorhexidine on dental plaque ureolysis and glycolysis.

We assessed the in vivo effects of zinc and chlorhexidine (CH) on plaque ureolysis and glycolysis in five volunteers. We monitored plaque pH by a surface glass electrode on two teeth in each subject, after topical application of either 5% wt/vol urea or 5% wt/vol glucose solutions. The recordings were repeated 15 and 75 min after a single mouthrinse, with either 20 mmol/L zinc acetate or 0.33 mmol/L CH diacetate. Ureolytic activity decreased significantly (p less than 0.03) up to 75 min after a single mouthrinse with the zinc-containing test solution. CH had no effect on plaque ureolytic activity. Acid production by dental plaque decreased significantly (p less than 0.01) up to 75 min after a single mouthrinse with either the zinc- or the CH-containing test solution.