This study evaluates if electric toothbrushes with a 3D action (rotation / oscillation and pulsation) are more effective than manual toothbrushes in removing plaque and reducing gingival inflammation in patients under orthodontic treatment with fixed appliances.

This trial is designed as a randomized, controlled, investigator blinded superiority trial, with two parallel groups and a 1:1 allocation ratio. Equal number of males and females will be allocated to each group.

One group of orthodontic patients will receive an electric toothbrush with orthodontic head and the other group will receive a manual orthodontic brush. Tooth brushing instructions will be provided. Measurements of two plaque indices and two gingival indices will be taken at baseline and at 3 monthly intervals.

Inclusion Criteria:

- Age between 12 and 16 years. Good general health according to a recent full medical history. Fixed labial orthodontic appliances on all teeth from central incisor to first molar (bands on first molars, metallic brackets-conventional, not self ligating-on other teeth), in both the maxillary and the mandibular arch, placed at least two months before the patient is accepted into the study and no more than two years.

Non-extraction orthodontic treatment. Plaque-induced gingivitis: patients will be included if they have gingival bleeding on at least 30% of the sites examined using the criteria for bleeding of the Modified Simplified Gingival Index.

Exclusion Criteria:

- Active caries. Periodontitis. Tooth agenesis (excluding third molars). Syndromes and craniofacial deformities. Current use of electric toothbrush. More than two cervical and/or proximal fillings. Dental prostheses or dental implants. Smoking or use of other tobacco products. Antibiotics during the last 2 months. Medication that may result in gingival enlargement (e.g. anticonvulsants, immunosuppressants, calcium channel blockers).

Disabilities that might affect toothbrushing skills (manual dexterity, mental disabilities).

Peri-oral or intra-oral piercing. Cardiac or other medical condition that requires antibiotic prophylaxis for dental treatment.

Participation in other trials.