Gingival Depigmentation With Diode and Er,Cr:YSGG Laser: A Split-mouth Trial (Laser)

April 11, 2026 updated by: Assoc.Prof.Dr. Nguyen Ngoc Rang, Can Tho University of Medicine and Pharmacy

Comparison of Diode and Er,Cr:YSGG Lasers in Gingival Depigmentation: a Split-mouth Randomized Trial

Gingival hyperpigmentation is a common physiological condition caused by excessive melanin deposition in oral mucosa, negatively affecting smile esthetics. Laser therapy has become an effective treatment option due to advantages such as minimal bleeding, reduced postoperative discomfort, and faster healing.

This clinical study aims to evaluate clinical characteristics of gingival pigmentation and compare treatment outcomes between diode laser and Er,Cr:YSGG laser techniques. Outcomes include pigmentation reduction, postoperative pain, wound healing, bleeding, patient satisfaction, and recurrence rate.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Gingival depigmentation is widely performed to improve smile esthetics in patients with excessive melanin pigmentation. Various treatment modalities have been proposed, including scalpel surgery, electrosurgery, cryotherapy, and laser therapy. Among these, diode laser and Er,Cr:YSGG laser have demonstrated promising results due to selective absorption by pigmented tissues and minimal tissue trauma.

This interventional clinical study compares two laser systems for treatment of gingival pigmentation. Clinical indices such as DOPI (Dummett-Gupta Oral Pigmentation Index), MPI (Melanin Pigmentation Index), postoperative pain (VAS scale), bleeding, wound healing (Landry index), and patient satisfaction will be evaluated at multiple follow-up time points including baseline, 1 day, 7 days, 1 month, and 3 months.

The study aims to determine the more effective laser modality in improving esthetic outcomes and minimizing complications.

Study Type

Interventional

Enrollment (Actual)

38

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Vietnam
      • Can Tho, Vietnam, 90000
        • Can Tho University of Medicine and Pharmacy
      • Can Tho, Vietnam, +84
        • Can Tho University of Medicine and Pharmacy

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • all patients exhibiting physiological melanin hyperpigmentation of score 1 or more according to the oral pigmentation index (DOPI) in the buccal maxillary gingiva

Exclusion Criteria:

  • history of systemic diseases related to pathology
  • participants with a systemic condition that could affect tissue healing (e.g., uncontrolled diabetes, autoimmune diseases, HIV, leukemia, etc.)
  • pregnancy and lactation
  • a history of smoking; previously used drugs (related to pigmentation) before the intervention within the last 6 months
  • contraindication for laser treatment.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Er,Cr:YSGG
This group treated with an erbium chromium-doped: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) laser at 2780 nm
Device: Er,Cr:YSGG laser
The group Er,Cr:YSGG (2780 nm) has a wavelength of 2780 nm, a pulse duration of 140-150 microseconds, a power output of 2.5W, a steam content of 11%, and a water content of 30%.
Other: Diode
This group treated with 940 nm diode laser.
Other: Diode laser
The Group Laser Diode (940 nm) has a wavelength of 940 to 10 nm, a pulse length of 15 microseconds, and a power output of 2.5 W. Activate the fiber laser head by touching the tip to the colored paper.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in gingival pigmentation measured by Dummett-Gupta Oral Pigmentation Index (DOPI)
Time Frame: Baseline, 7 days, 1 month, 3 months
Assessment of gingival pigmentation using the DOPI score.
Baseline, 7 days, 1 month, 3 months
Change in gingival pigmentation measured by Melanin Pigmentation Index (MPI)
Time Frame: Baseline, 7 days, 1 month, 3 months
Assessment of gingival pigmentation using the MPI score.
Baseline, 7 days, 1 month, 3 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in postoperative pain measured by Visual Analog Scale (VAS)
Time Frame: 1 day, 7 days
Pain intensity assessed using the Visual Analog Scale (VAS) ranging from 0 to 10
1 day, 7 days

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in wound healing assessed by Landry, Turnbull and Howley Healing Index Healing assessed using Landry, Turnbull and Howley index
Time Frame: 7 days, 1 month
Wound healing evaluated using the Landry, Turnbull and Howley Healing Index, scored from 1 to 5
7 days, 1 month

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Can Tho University of Medicine and Pharmacy

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 1, 2023

Primary Completion (Actual)

May 1, 2024

Study Completion (Actual)

May 1, 2025

Study Registration Dates

First Submitted

September 7, 2025

First Submitted That Met QC Criteria

April 7, 2026

First Posted (Actual)

April 9, 2026

Study Record Updates

Last Update Posted (Actual)

April 14, 2026

Last Update Submitted That Met QC Criteria

April 11, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 23.350.HV/PCT-HĐĐĐ (Other Identifier: Can Tho University of Medicine and Pharmacy)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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