Low-level Laser Therapy as an Adjunct to Non-surgical Periodontal Treatment

Inclusion Criteria: * Stage 3-4, Grade C periodontitis (at least one site with probing depth (PD) and clinical attachment level (CAL) ≥5 mm in their incisors and/or first molars and at least 6 other teeth with similar PD and CAL measurements, with alveolar bone loss confirmed by radiography; familial aggregation; * presence of ≥16 teeth; * no periodontal treatment in the 6 months prior to data collection; * non-smoker Exclusion Criteria: * systemic problems, including a medical history of cancer, rheumatoid arthritis, diabetes mellitus, or cardiovascular disease; * compromised immune system; * pregnancy, menopause, or lactation; * ongoing drug therapy that might affect the clinical characteristics of periodontitis; * use of systemic antimicrobials during the 6 weeks prior to data collection