The effect of low‐level laser therapy as an adjunct to non‐surgical periodontal treatment on gingival crevicular fluid levels of transforming growth factor‐beta 1, tissue plasminogen activator and plasminogen activator inhibitor 1 in smoking and non‐smoking chronic periodontitis patients: A split‐mouth, randomized control study

Background and Objective This study aimed to investigate the effects of low‐level laser therapy (LLLT) as an adjunct to scaling and root planing (SRP) on smoking and non‐smoking patients with chronic periodontitis. Material and Methods The study was conducted using a split‐mouth design with 30 patients with chronic periodontitis (15 smokers, 15 non‐smokers) and 30 healthy individuals matched for age, sex and smoking status as controls. Groups were constituted as follows: Cp+SRP+Sham: non‐smokers with chronic periodontitis treated with SRP; Cp+SRP+LLLT: non‐smokers with chronic periodontitis treated with SRP+LLLT; SCp+SRP+Sham: smokers with chronic periodontitis treated with SRP; SCp+SRP+LLLT: smokers with chronic periodontitis treated with SRP+LLLT; C: control group comprised of periodontally healthy non‐smokers; SC: control group comprised of periodontally healthy smokers. LLLT was first applied on the same day as SRP and again on days 2 and 7 after SRP treatment. Clinical parameters were recorded before non‐surgical periodontal treatment (baseline) and on day 30. Gingival crevicular fluid samples were collected before periodontal treatment (baseline) and during follow‐up visits on days 7, 14 and 30. Gingival crevicular fluid transforming growth factor (TGF)‐β1, tissue plasminogen activator (tPA) and plasminogen activator inhibitor 1 (PAI‐1) levels were measured using enzyme‐linked immunosorbent assay. Results All clinical parameters showed significant reductions between baseline and day 30 following SRP treatment in both the LLLT and sham groups (P.05). Gingival crevicular fluid PAI‐1 levels decreased significantly in the SCp+SRP+sham and SCp+SRP+LLLT groups (P