Objective: This parallel, randomized, examiner-blind clinical trial aimed to evaluate the efficacy of two different toothbrushes (manual and sonic) on plaque control in adolescents. Material and Methods: This study enrolled 56 volunteers, randomly allocated to two different groups: group A (n = 28) for the manual toothbrush (Curaprox 5460 Ultra Soft ®) and group B (n = 28) for the sonic toothbrush (Edel White ®). Mean age was 17.2 ± 1.1 years. A calibrated periodontist performed a periodontal evaluation to assess the presence of plaque with the Turesky Modification of the Quigley Hein Plaque Index (PI) and the gingival inflammation with the Silness & Löe Gingival Index (GI). Adolescents received instructions about the mechanical control of plaque at baseline (T0), with a reexamination after 3 months (T1) and 6 months (T2). Non-parametric Mann Whitney test was used to compare the differences between the two toothbrush groups and the Friedman test was used for the comparisons between times. Results: There has been PI reduction concerning the study times (T0, T1 and T2, p<0.05), but not between the groups A and B (p>0.05). As for GI there has been no significant difference between the groups and between the study times (p>0.05). Conclusion: Both toothbrushes were efficient in the control of supragingival plaque (visible biofilm).