Background: Aim of this randomized controlled parallel-designed study was to evaluate the effects of diode laser as an adjunct to mechanical periodontal treatment on clinical parameters and gingival crevicular fluid (GCF) volume of the residual pockets diagnosed following initial periodontal treatment in chronic periodontitis (CP) patients.

Methods: A total of 84 residual pockets on single-rooted teeth in 11 CP patients were included and randomly assigned into 3 groups. Residual pockets were treated either only by mechanical treatment (Group M) (n=28), only by diode laser disinfection (Group L) (n=28) or by combination of these techniques (Group M+L) (n=28). Plaque index, gingival index (GI), bleeding on probing (BoP), probing depth (PD), clinical attachment level and gingival recession were assessed at baseline and 8 weeks after treatment of residual pockets. GCF samples were collected at baseline, 1 and 8 weeks after treatment.

Inclusion Criteria:

• Systemically healthy,
• Non-smoker,
• Chronic periodontitis diagnosed according to Armitage 1,
• Aged between 35 and 65,
• Not received any periodontal treatment within the last 3 months,
• Have horizontal bone loss radiographically,
• Presence at least 20 natural teeth except third molars
• Consent to participate in the study.

Exclusion Criteria:

• Any systemic disease that might interfere with the prognosis of periodontal disease (i.e. diabetes mellitus, HIV infection),
• Smoking,
• Antibiotics, anti-inflammatory drugs or any other medication taken within the previous 6 months that may affect the outcome of the study,
• Any physical limitations or restrictions that might preclude normal oral hygiene procedures.