Methods: Twelve healthy volunteers, from 18 to 30 years-old, were randomly allocated into a four period crossover trial. The mouthrinses tested were Listerine®, Plax®, the herbal mouthrinse containing extract and essential oil and a placebo with no active ingredient as a positive control. All volunteers were asked to refrain from any kind of oral hygiene for 24 hours. After then, they had dental biofilm evidenced by basic fuchsin in order to establish the baseline levels. Stained areas were marked in an appropriate dental record. Conventional brush and toothpaste were provided to participants, who cleaned their teeth and then the mouthrinses were used for 1 minute. New plaque disclosure and new dental record labeled with PI were performed after 1 week of mouthrinse association use. The same period for washout was established to avoid carry-over effect. Data were submitted to statistical analysis using Wilcoxon and Friedman tests.
Results: The four mouthrinses were able to reduce PI immediately (Wilcoxon p=0,002) and after one week of use (Wilcoxon p<0,02). There were no significant differences among themselves immediately (Friedman p=0,602) or at the end of 1 week period of use (Friedman p=0,674).
Conclusion: The mouthrinse containing extract and essential oil of Baccharis dracunculifolia DC was as effective as the others mouthrinses for reducing supragingival plaque formation, when associated to mechanical oral hygiene.