Laser Treatment With Methylene Blue vs. Nanoparticle-Assisted Photodynamic Therapy for Gingival Pigmentation: A Randomized Clinical Trial

This prospective, randomized, controlled, single-blinded, three-arm clinical trial compared the clinical effectiveness of conventional methylene blue-mediated photodynamic therapy (MB-PDT) and methylene blue nanoparticle-mediated photodynamic therapy (MB-NP-PDT) as adjuncts to diode-laser treatment of physiological gingival pigmentation. A total of 45 systemically healthy participants with physiological gingival pigmentation were randomly allocated in a 1:1:1 ratio to three groups: diode-laser gingival depigmentation alone, conventional 0.1% methylene blue PDT followed by diode-laser depigmentation, or 0.1% methylene blue nanoparticle PDT followed by diode-laser depigmentation. Participants were followed for 6 months. The study assessed gingival pigmentation reduction, complete pigmentation clearance, recurrence, objective gingival color changes, epithelialization and healing time, postoperative pain, patient satisfaction, and treatment-related adverse events.

Inclusion Criteria: Patients with physiological gingival pigmentation confirmed by clinical examination. Age range: 18-50 years. Patients with no history of systemic diseases or conditions that could affect wound healing (e.g., diabetes, autoimmune diseases). Patients willing to undergo laser treatment and provide informed consent. Non-smokers or individuals who have stopped smoking for at least six months. Exclusion Criteria: Patients with pathological gingival pigmentation (e.g., associated with syndromes or systemic conditions). Use of medications affecting pigmentation or healing (e.g., anticoagulants, immunosuppressants). Pregnant or lactating women or those taking contraceptive drugs. Individuals with known allergies to methylene blue or nanoparticles.