Patients who had teeth with 30% periodontal bone loss, presence of at least two nonadjacent sites per quadrant with probing pocket depths of ≥5 mm, and bleeding on probing were assigned as chronic periodontitis group Patients who have smoked for at least 10 years and a minimum of 10 cigarettes per day were assigned as current smokers.

Patients who had teeth with 30% periodontal bone loss, presence of at least two nonadjacent sites per quadrant with probing pocket depths of ≥5 mm, and bleeding on probing were assigned as chronic periodontitis group Never smoked patients were included into the nonsmoker group

Individuals were diagnosed periodontally healthy as without attachment loss, periodontal disease history, whole mouth bleeding scores of <10% and a probing depth of ≤3 mm Patients who have smoked for at least 10 years and a minimum of 10 cigarettes per day were assigned as current smokers.

Individuals were diagnosed periodontally healthy as without attachment loss, periodontal disease history, whole mouth bleeding scores of <10% and a probing depth of ≤3 mm Never smoked patients were included into the nonsmoker group

Scaling and root planing and polishing with specific curettes were performed to patients with CP and oral hygiene education was provided to each patient.

Total amount of Peptidoglycan Recognition Protein-1 (µg) in gingival crevicular fluid

Clinical attachment level (mm) (from cemento-enamel junction to the base of periodontal pocket)