Comparison between plaque inhibiting effect of chlorhexidine and aqueous solutions of copper- and silver-ions

Rinsing experiments with chlorhexidine, copper and silver solutions were performed in a group of volunteers. The plaque was measured after rinsing with the test solutions for 4 d and no mechanical oral hygiene allowed. Chlorhexidine and copper, both 1.1 mM solutions, gave reduced plaque scores, chlorhexidine being slightly more effective than copper, but the difference was not statistically significant. A 1.1 mM solution of silver nitrate also showed a plaque inhibiting effect, statistically significant from the placebo, but the effect was also significantly less than when chlorhexidine or copper were used. Copper ions may be of clinical interest because this is an essential metal in human nutrition with low toxicity.