RESUMO
OBJECTIVES: To evaluate the effect of ozonated water in early plaque formation and gingival inflammation. MATERIALS AND METHODS: This was a randomized, controlled, double-blind, crossover clinical trial with two experimental periods of 96 h each, with 10 washout days between them. The sample consisted of 42 dental students divided into Test Group, mouthwash of ozonated water, and Control Group, bidistilled water mouthwash. The participants were instructed not to perform oral hygiene and used the assigned mouthwash under supervision once a day. For the investigation of the initial subgingival biofilm formation, the Plaque Free Zone Index was used at 24, 48, 72, and 96 h. The volume of gingival crevicular fluid, a questionnaire for taste perception assessment, and analysis of the adverse effects were also carried out. RESULTS: The percentage of conversion scores 0 and 1 to 2 of PFZ Index, the main outcome, for all dental surfaces showed no statistical difference between Test and Control groups, with 19.07 and 19.79, respectively. Also, there was not a significant difference in the score frequencies at each time point. Evaluation of GCF demonstrated that both groups had an increase in volume during experimental periods and that there was no statistically significant difference among groups. Test group had worse evaluation of taste perception and more adverse effects. CONCLUSIONS: Ozonated water seems not to affect the formation of supra and subgingival biofilms, as well as gingival inflammation. CLINICAL SIGNIFICANCE: Mouthwash with ozonated water once a day do not affect supra and subgingival biofilm formation.