Antiplaque Effect of Essential Oils and 0.2% Chlorhexidine on an In Situ Model of Oral Biofilm Growth: A Randomised Clinical Trial

ObjectiveTo evaluate the in situ antiplaque effect after 4 days of using of 2 commercial antimicrobial agents in short term on undisturbed plaque-like biofilm.Trial Design and ParticipantsAn observer-masked, crossover randomised clinical trial on 15 oral and systemically healthy volunteers between 20–30 years who were randomly and sequentially allocated in the same group which performed 3 interventions in different randomised sequences.InterventionThe participants wore an appliance in 3 different rinsing periods doing mouthwashes twice a day (1/0/1) with essential oils, 0.2% chlorhexidine or sterile water (negative control). At the end of each 4-day mouthwash period, samples were removed from the appliance. Posteriorly, after bacterial vital staining, samples were analysed using a Confocal Laser Scanning Microscope.Main Outcome MeasuresBacterial vitality, thickness and covering grade by the biofilm after 4 days of applying each of the mouthwashes.ResultsThe essential oils and the 0.2% chlorhexidine were significantly more effective than the sterile water at reducing bacterial vitality, thickness and covering grade by the biofilm. No significant differences were found between the 0.2% chlorhexidine and the essential oils at reducing the bacterial vitality (13.2% vs. 14.7%). However, the 0.2% chlorhexidine showed more reduction than the essential oils in thickness (6.5 μm vs. 10.0 μm; pvs. 54.3%; pConclusionThe essential oils and 0.2% chlorhexidine showed a high antiplaque effect. Although the 0.2% chlorhexidine showed better results with regard to reducing the thickness and covering grade by the biofilm, both antiseptics showed a high and similar antibacterial activity.Clinical RelevanceDaily essential oils or 0.2% chlorhexidine mouthwashes are effective when reducing dental plaque formation in the short term. Although 0.2% chlorhexidine continues to be the “gold standard” in terms of antiplaque effect, essential oils could be considered a reliable alternative.Trial RegistrationClinicalTrials.gov NCT02124655