The purpose of this study is to compare the efficacy of photoablative and photodynamic diode laser in adjunct to scaling-root planing (PAPD+SRP) and SRP alone for the treatment of periodontitis.

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.

Efficacy evaluations, including probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP) was performed at baseline ,1year, and year 3 using a conventional manual periodontal probe. Polymorphonuclear leukocytes (PMN), erythrocytes (RBC), damaged epithelial cells (DEC) and bacteria were assayed by cytofluorescence on gingival exfoliative samples at baseline, 6 month and 1, 3, 5 years.

Inclusion Criteria:

1. Periodontitis:Presence of at least two teeth with at least one site with pocket probing depth (PD) ranging from 4 to 10 mm in each upper maxillary quadrant and with bleeding on probing (BOP)
2. A minimum of five natural teeth in each studied quadrant.

Exclusion Criteria:

1. History of systemic diseases (diabetes mellitus, cancer, HIV, metabolic and endocrine diseases)
2. Pregnancy or lactation
3. Chronic high-dose steroid use
4. Previous or current radiation or immunosuppressive therapies
5. Ongoing orthodontic treatments
6. Extensive carious lesions
7. Recurrent antibiotic medications during the 6 months preceding the study
8. Class III tooth mobility
9. Heavy contamination by spirochetes and fungal pathogens on tongue and oral mucosa