Whole-mouth clinical examinations will be performed in periodontally healthy patients 15 days before, at the day of bonding and also 3 and 6 months after braces bonding. Hard and soft tissues status, presence of gingivitis and amount of dental plaque will be monitored to determine mouthwashes efficacy. At these same time-points plaque samples will be collected from dental sites and braces surfaces aiming at determining total levels of bacteria and levels of specific bacteria related to gum disease. After a full-mouth ultrasonic debridement to remove dental plaque, stains and tartar, patients will be randomly assigned to an Essential oils, Cetylpyridinium chloride or a placebo mouthwash for 6 months (40 ml/day). Further, samples of orthodontic wires will be analyzed under microscopy to check whether regular use of mouthwashes increases the risk of corrosion or not.