Residual pockets and furcation defects are challenging sites that require additional periodontal therapy. The aim of this study is evaluate 1)the effect of a single photodynamic therapy (PDT) as monotherapy residual pockets in single rooted teeth and 2) the effect of PDT in association with scaling and root planing (SRP) in class II furcation lesions with probing pocket depth (PPD) >5mm and bleeding on probing (BoP). A blind randomized controlled clinical trial was conducted in subjects presenting at least three residual pockets in single root teeth and subjects with at least one molar presenting class II furcation defect. To evaluate the effect of a single PDT as monotherapy in residual pockets, the selected sites were assigned to receive: PDT alone, photosensitizer alone or SRP alone. To evaluate the effect of PDT in association with SRP in class II furcation lesions, the selected sites were assigned to PDT+SRP or SRP alone. Clinical, microbiological and immunoenzymatic analyses were assessed at baseline, 3 and 6 months post-therapies.

Residual pockets and class II furcation lesions are challenging sites that require additional periodontal therapy. The aims of this study were to evaluate:

1) the effect of a single PDT as monotherapy residual pockets in single rooted teeth and 2) the effect of PDT in association with SRP in class II furcation lesions.

A blind randomized controlled clinical trial was conducted in subjects presenting at least three residual pockets in single root teeth and subjects with at least one molar presenting class II furcation involvement.

To evaluate the effect of a single PDT as monotherapy in residual pockets, the selected sites were assigned to receive one of following therapies: PDT alone, photosensitizer alone or SRP alone.

To evaluate the effect of PDT in association with SRP in class II furcation lesions, the selected sites were assigned to receive PDT+SRP or SRP alone. Microbiological, immunoenzymatic analyses and clinical parameters: probing pocket depth (PPD), position of the gingival margin (PGM), relative clinical attachment level (RCAL), full mouth plaque (FMPS) and bleeding score (FMBS), will be assessed at baseline,3 and 6 months post-therapies.

Inclusion Criteria:

• diagnosis of chronic periodontitis (according to the criteria of the 1999 international classification)
• at least three contralateral single rooted teeth with residual PPD > 5mm with bleeding on probing (BoP) in supportive periodontal therapy or with at least one molar presenting class II furcation defect.

Exclusion Criteria:

• pregnancy
• lactation
• current smoking and smoking within the past 10 years
• antibiotic therapies in the previous 6 months
• use of mouth rinses containing antimicrobials in the preceding 2 months
• systemic conditions that could affect the progression of periodontitis
• orthodontic appliances
• use of long-term administration of anti-inflammatory and immunosuppressive medications