NCT07325825

Brief Summary

This randomized controlled clinical trial aims to compare the effectiveness of topical licorice extract gel and diode laser (445 nm) in the treatment of physiologic gingival pigmentation. Twenty-four adult patients presenting with physiologic melanin pigmentation in the anterior esthetic zone of the maxillary or mandibular gingiva will be randomly allocated into two equal groups. One group will be treated with diode laser therapy, while the other group will receive topical licorice extract gel. Clinical outcomes will be assessed using standardized gingival pigmentation indices and patient satisfaction questionnaires over a follow-up period of 36 weeks.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
26

participants targeted

Target at below P25 for not_applicable

Timeline
Completed

Started Apr 2025

Shorter than P25 for not_applicable

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Start

First participant enrolled

April 1, 2025

Completed
9 months until next milestone

First Submitted

Initial submission to the registry

December 24, 2025

Completed
8 days until next milestone

Primary Completion

Last participant's last visit for primary outcome

January 1, 2026

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

January 1, 2026

Completed
7 days until next milestone

First Posted

Study publicly available on registry

January 8, 2026

Completed
Last Updated

January 15, 2026

Status Verified

January 1, 2026

Enrollment Period

9 months

First QC Date

December 24, 2025

Last Update Submit

January 13, 2026

Conditions

Gingival Hyperpigmentation

Keywords

Gingival pigmentationDiode laserLicorice extract gel

Outcome Measures

Primary Outcomes (2)

  • Change in gingival pigmentation intensity

    Degree of gingival pigmentation assessed using the Dummett-Gupta Oral Pigmentation Index (DOPI; scores range from 0 to 3), with higher scores indicating increased pigmentation intensity.

    Baseline, 1 week, 4 weeks, 12 weeks and 36 weeks

  • Change in gingival pigmentation distribution

    Gingival pigmentation distribution was assessed using the Gingival Pigmentation Index (GPI). The GPI is an ordinal scale ranging from 0 to 3, where 0 indicates absence of pigmentation and 3 indicates widespread gingival pigmentation. Higher scores represent greater extent of gingival pigment distribution (worse pigmentation).

    Baseline, 1 week, 4 weeks, 12 weeks and 36 weeks

Secondary Outcomes (2)

  • Participant Satisfaction

    3 months post-treatment

  • Postoperative pain intensity (laser group only)

    Immediately post-procedure, Day 1 and Day 7 postoperatively

Study Arms (2)

Diode Laser Group

ACTIVE COMPARATOR

Participants receive gingival depigmentation using a 445 nm diode laser.

Device: Diode Laser 445 nm

Licorice Extract Gel Group

EXPERIMENTAL

Participants apply topical licorice extract gel to pigmented gingival areas three times daily.

Drug: Licorice Extract Gel

Interventions

Licorice Extract GelDRUG

Topical licorice extract gel applied to pigmented gingival areas three times daily for one month, with continuation for a second and third month if required.

Licorice Extract Gel Group
Diode Laser 445 nmDEVICE

Gingival depigmentation performed using a diode laser with a wavelength of 445 nm in continuous wave mode at 1 W power.

Diode Laser Group

Eligibility Criteria

Age18 Years - 50 Years
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64)

You may qualify if:

  • Adults (18 to 50 years old) of either sex with physiologic melanin pigmentation in the anterior esthetic zone of the maxillary or mandibular gingiva.
  • Systemically healthy individuals

You may not qualify if:

  • Smokers
  • Pregnant or lactating females
  • Patients taking drugs associated with gingival pigmentation
  • Patients with periodontal disease
  • History of gingival depigmentation
  • Known hypersensitivity to licorice extract
  • Poor oral hygiene
  • Presence of systemic diseases

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Oral Medicine and Diagnosis Clinic, Faculty of Dentistry, Alexandria University

Alexandria, Alexandria Governorate, 21526, Egypt

Location

MeSH Terms

Interventions

Lasers, Semiconductor

Intervention Hierarchy (Ancestors)

LasersOptical DevicesEquipment and SuppliesRadiation Equipment and Supplies

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
SINGLE
Who Masked
OUTCOMES ASSESSOR
Purpose
TREATMENT
Intervention Model
PARALLEL
Model Details: intervention (control group): Diode laser 445 nm intervention (test group): topical licorice extract gel
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Master's degree researcher, department of Oral Medicine and Diagnosis

Study Record Dates

First Submitted

December 24, 2025

First Posted

January 8, 2026

Study Start

April 1, 2025

Primary Completion

January 1, 2026

Study Completion

January 1, 2026

Last Updated

January 15, 2026

Record last verified: 2026-01

Locations

EG(1)