The present study is a randomized, blinded, controlled clinical trial, which used a split-mouth design. All patients were informed individually about the nature of the proposed treatment, and informed consent forms were signed. Twenty-four patients were studied. Maxillary left or right quadrants were randomly assigned to PAPD laser treatment or sham-treatment and SRP. PAPD consisted of: i) photoablative gingival epithelium with diode laser (λ 810 nm, 1 W); ii) photodynamic treatments (4-10 weekly) with diode laser (λ 635 nm, 100 mW) and 0.3% methylene blue as photoactive antiseptic, performed after SRP. Sham-treatment was similar but with switched off laser.