Impact of low-level laser therapy as an adjunct to non-surgical periodontal treatment on the levels of tissue plasminogen activator and plasminogen activator inhibitor 1 in Stage 3–4, Grade C periodontitis patients: a split-mouth, randomized control study

Aim: To investigate the effects of low-level laser therapy (LLLT) as an adjunct to non-surgical periodontal treatment (NSPT) on the plasminogen-activating system. Materials and Methods: Stage 3–4 Grade C periodontitis and age-gender-matched healthy individuals participated in the split-mouth study (ClinicalTrials.gov identifier, NCT05233501). The study groups were Periodontitis/NSPT (Sham); Periodontitis/NSPT + LLLT (LLLT); Healthy (Control). Following NSPT, LLLT was applied on Days 0, 2 and 7. Clinical parameters were recorded at baseline and on Day 30. Gingival crevicular fluid (GCF) was collected at baseline, on days 7, 14, and 30; tissue-type plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) levels were measured with ELISA. Results: Clinical parameters, total GCF tPA (tPA_t) and PAI-1 (PAI-1_t) levels significantly reduced in LLLT and Sham groups (< 0.001). GCF tPA_t levels in LLLT were significantly lower (< 0.05) than Sham on Day 7. GCF tPA_t levels in periodontitis groups were significantly higher than the Control at baseline, on Days 7 and 14 (< 0.01). By Day 30, both groups decreased to control levels (> 0.05). GCF PAI-1_t levels were significantly lower in LLLT than the Sham on day 30 (< 0.01), comparable to healthy controls (> 0.05). Conclusion: Adjunctive LLLT modulates the plasminogen activating system in severe periodontitis by altering GCF tPA and PAI-1 levels. Clinical relevance: LLLT as an adjunct to non-surgical periodontal treatment in patients with Stage 3–4 Grade C leads to reduced plasminogen activation.