The efficacy of three formulations of Lippia sidoides Cham. essential oil in the reduction of salivary Streptococcus mutans in children with caries: A randomized, double-blind, controlled study

Essential oils of many plants have been previously tested in the treatment of oral diseases and other infections. This study was a randomized, double-blind, in parallel with an active control study, which aimed to evaluate the efficacy of three formulations of the Lippia sidoides Cham. essential oil (LSO) in the reduction of salivary Streptococcus mutans in children with caries. 81 volunteers, aged 6-12 years, both genders, with caries, were recruited to participate in this study, and randomly assigned to either one of five different groups. Each group received topical treatment with either 1.4% LSO toothpaste, 1.4% LSO gel, 0.8% LSO mouthwash, 1% chlorhexidine gel, or 0.12% chlorhexidine mouthwash. A 5-ml volume of each gel was placed inside disposable trays, and applied for 1 min, every 24 h, for 5 consecutive days. The mouthwash groups used 5-ml volume of a mouthwash inside disposable syringes. In the toothpaste group, children brushed their teeth for 1 min, once a day for 5 days. Saliva was collected before and after treatment. MS colonies were counted, isolated and confirmed through biochemical tests. Differences in MS levels measured in different days within the same treatment group was only verified with LSO toothpaste, chlorhexidine gel and chlorhexidine mouthwash. Comparison between groups of LSO mouthwash, toothpaste and gel showed that the toothpaste group expressed significantly lower MS levels than the mouthwash and gel groups at day-30. Chlorhexidine significantly reduced MS levels after 5 days of treatment, but these levels returned to baseline in other periods of the study. LSO toothpaste reduced MS levels after 5 days of treatment, and MS levels remained low and did not return to baseline during subsequent analysis. Hence, LSO toothpaste demonstrated the most long-lasting MS reduction in saliva, whereas other LSO formulations did not effectively reduce MS levels in children with dental caries.