The purpose of this blind randomized clinical trial is to evaluate different frequencies in self-mechanical control of plaque in individuals with historic of periodontitis and in periodic and preventive maintenance in order to assess which frequencies are compatible with maintaining gingival health.

Thirty nine subjects with at most 5% of the sites for GI= 2 (gingival health) will be randomized into three groups with different frequencies in self-mechanical control of plaque: Group 12 hours, 24 hours and 48 hours. The exams of plaque index, gingival index, probing depth, bleeding on probing, clinical attachment level and gingival crevicular fluid will be performed at baseline, 15, 30, 60 and 90 days.

Inclusion Criteria:

• Individuals with historic of periodontitis (loss of interproximal insertion ≥3mm in two or more non-adjacent teeth) treated in the Clinic of Postgraduate Periodontics at the Federal University of Santa Maria and included in the periodontal maintenance program;
• Minimum age of 35;
• Individuals with at least 12 teeth in the mouth;
• Maximum of 15% of sites with gingivitis;
• Maximum of 25% of sites with bleeding on probing.

Exclusion Criteria:

• Smokers;
• Pregnant women;
• Individuals with dryness of the mouth (xerostomia);
• Diabetics;
• Psychomotor disturbances;
• Orthodontic equipment;
• Antimicrobial prophylaxis;
• Individuals using any medication associated with gingival overgrowth;
• Individuals that used antibiotic/anti -inflammatory in recent 3 months.