Over time, many different types of manual and electric toothbrushes have been produced. A systematic review has shown that some electric toothbrushes are more effective at removing bacterial plaque than manual toothbrushes. A new U-shaped electric toothbrush with silicone bristles has recently been produced that has a fully automatic and simultaneous action on both arches. However, its efficacy in removing bacterial plaque is not clear at the moment, as no randomized study has been published on this type of toothbrush.

The aim of this study is to compare the efficacy in terms of bacterial plaque removal in a single use of a new automatic U-shaped electric toothbrush, compared with the usual home toothbrushing procedure, a conventional electric toothbrush, and negative control (no toothbrushing) in a group of volunteer students of the School of Dentistry of the University of Florence, Italy.

Primary endpoint will be the difference in "full mouth plaque score" between before and after brushing. Secondary endpoints will be feeling of "clean mouth" evaluated on a VAS (Visual Analogue Scale) scale from 0 to 10 where 0 indicates no feeling of clean mouth and 10 maximum feeling of clean mouth.

This study will be a monocentric, randomized, controlled, superiority, cross-over study, with blind examiner and 4 therapies (U-shaped electric toothbrush, usual home toothbrushing procedure, conventional electric toothbrush, no toothbrushing), carried out in a single session with an interval of one week between the 4 therapies.

Study population will be students of the School of Dentistry who are healthy volunteers. Number of patients to be enrolled: 22. Inclusion criteria: age between 18 and 30 years; no fixed orthodontic appliance; presence of at least 20 teeth; Full mouth plaque score (FMPS) above 40%.

Exclusion criteria: subjects with manual disabilities to perform normal oral hygiene maneuvers; subjects allergic to silicone.

Inclusion Criteria:

• Age between 18 and 30 years;
• no fixed orthodontic equipment;
• presence of at least 20 teeth;
• Full mouth plaque score (FMPS) above 40%.

Exclusion Criteria:

• Subjects with manual disabilities to perform normal oral hygiene maneuvers;
• Subjects allergic to silicone