Evaluation of Photodynamic Treatment FOTOSAN® Efficacy in Periodontology

Inclusion Criteria: * aged 40 years * signed informed consent * generalized severe chronic periodontitis * patient with at least 24 teeth * more than 30% of sites with clinical attachment loss \>5mm- at least 5 sites with pocket depth \>4mm per quadrant- at least one molar per quadrant- evidenced bone loss on radiographs- bleeding on probing ≥30% Exclusion Criteria: * aggressive periodontitis * smoking more than 10cig/day * patient with endocarditis risk or need of antibiotic prophylaxis * pregnant women * patient included in other trials * patient under guardianship * patient treated with antibiotics, anti-inflammatory, and other drugs (inhibitors of calcium channels…) influencing periodontal status within 6 months before examination * patient suffering from diseases influencing periodontal status (diabetes…) * patient periodontally treated with root planing or periodontal surgery within 1 year before examination * patient with scheduled extensive prosthetic treatment * patient with a high haemorrhagic risk (INR\>4) * impossible patient cooperation