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

Roaa Hadi Hussein Jasem

Status: Completed

Conditions: Physiological Gingival Pigmentation

Treatments: Procedure: Laser-Assisted Gingival Depigmentation; Drug: Drug: Conventional Methylene Blue-Mediated Photodynamic Therapy; Drug: Drug: Methylene Blue Nanoparticle-Mediated Photodynamic Therapy

Study type: Interventional

Funder types: Other

Identifiers

NCT06834087

KFSIRB200-489

Details and patient eligibility

About

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.

Enrollment: 45 patients

Sex: All

Ages: 18 to 50 years old

Volunteers: No Healthy Volunteers

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.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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45 participants in 3 patient groups

Arm 1 (Control): Diode-Laser Gingival Depigmentation Alone

Active Comparator group

Description:

Participants assigned to this arm received diode-laser gingival depigmentation alone using the SiroLaser Blue diode laser (Dentsply Sirona). The laser was operated at a wavelength of 970 nm and an output power of 1.5 W in continuous-wave mode. A 320-µm fiber tip was used in contact mode and moved continuously with gentle sweeping strokes over the pigmented gingival surface for approximately 30 seconds per treatment site.

Treatment:

Procedure: Laser-Assisted Gingival Depigmentation

Arm 2: Conventional Methylene Blue-PDT Plus Diode-Laser Depigmentation

Experimental group

Description:

Participants assigned to this arm received photodynamic therapy using conventional 0.1% methylene blue before diode-laser gingival depigmentation. The methylene blue solution was applied uniformly to the pigmented gingival surface using a sterile microbrush and allowed to remain in contact with the gingiva for 2 minutes before photoactivation. Photodynamic activation was performed using a 660-nm diode laser at an output power of 100 mW in continuous-wave, non-contact mode for 60 seconds per treatment site. The gingival surface was subsequently irrigated with sterile saline to remove residual photosensitizer. Gingival depigmentation was then performed using a 970-nm diode laser at 1.5 W in continuous-wave mode with a 320-µm fiber tip in contact mode for approximately 30 seconds per treatment site.

Treatment:

Drug: Drug: Conventional Methylene Blue-Mediated Photodynamic Therapy

Arm 3: Methylene Blue Nanoparticle-PDT Plus Diode-Laser Depigmentation

Experimental group

Description:

Participants assigned to this arm received photodynamic therapy using a 0.1% methylene blue nanoparticle formulation before diode-laser gingival depigmentation. The nanoparticle formulation was applied uniformly to the pigmented gingival surface using a sterile microbrush and allowed to remain in contact with the gingiva for 2 minutes before photoactivation. Photodynamic activation was performed using a 660-nm diode laser at an output power of 100 mW in continuous-wave, non-contact mode for 60 seconds per treatment site. The gingival surface was subsequently irrigated with sterile saline to remove residual formulation. Gingival depigmentation was then performed using a 970-nm diode laser at 1.5 W in continuous-wave mode with a 320-µm fiber tip in contact mode for approximately 30 seconds per treatment site.

Treatment:

Drug: Drug: Methylene Blue Nanoparticle-Mediated Photodynamic Therapy