Effects of a zinc citrate mouthwash on dental plaque and salivary bacteria.

A double-blind crossover trial was carried out to assess the effect of zinc citrate on plaque accumulation in vivo and to measure total salivary aerobes and anaerobes both during the trial and throughout the day following a single rinse. When compared to the placebo, zinc citrate significantly reduced the plaque accumulation in the subjects. However, the mean reduction was small and of questionable clinical importance. A progressive increase in plaque was observed throughout both active and placebo 7-day rinsing periods. There was no significant reduction in salivary bacterial counts either during the crossover study or during the day following a single rinse with zinc citrate.