Gingival HyperpigmentationNCT07325825
Licorice Extract Gel Versus Diode Laser for Physiologic Gingival Pigmentation
A study testing Diode Laser 445 nm and Licorice Extract Gel in people with Gingival Hyperpigmentation, run by Alexandria University at 1 site in Egypt.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 50 years
- Conditions the study is for
- Gingival Hyperpigmentation
- What is being tested?
- Diode Laser 445 nm and Licorice Extract Gel
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 26 participants
- Where
- 1 siteEgypt
- Study dates
- 1 Apr 2025to 1 Jan 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 50 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- 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
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country.
Egypt1 site
Oral Medicine and Diagnosis Clinic, Faculty of Dentistry, Alexandria University
Alexandria, Alexandria Governorate, 21526
About this study
Official title: A Comparative Evaluation of the Effectiveness of Topical Licorice Extract Gel and Diode Laser 445 nm on Physiologic Gingival Pigmentation
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.
Read the detailed description
This randomized controlled clinical trial will be conducted at the outpatient clinic of the Department of Oral Medicine, Periodontology, Oral Diagnosis and Oral Radiology, Faculty of Dentistry, Alexandria University, Egypt.
Eligible participants aged 18-50 years with physiologic gingival pigmentation will be randomly assigned into two groups. Group A will receive gingival depigmentation using a 445 nm diode laser, while Group B will receive topical licorice extract gel applied three times daily.
The intensity and distribution of gingival pigmentation will be evaluated using the Dummett-Gupta Oral Pigmentation Index (DOPI) and Gingival Pigmentation Index (GPI). Patient satisfaction will also be assessed. Clinical evaluations will be performed at baseline, 1 week, 4 weeks, 12 weeks and 36 weeks after treatment.
- Conditions
- Gingival Hyperpigmentation
- Being tested
- Diode Laser 445 nm, Licorice Extract Gel
- Keywords
- Gingival pigmentation, Diode laser, Licorice extract gel
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
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.
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.
| Study group | Role | What they receive |
|---|---|---|
| Diode Laser Group | Active comparator | Participants receive gingival depigmentation using a 445 nm diode laser. Receives: Device: Diode Laser 445 nm |
| Licorice Extract Gel Group | Experimental | Participants apply topical licorice extract gel to pigmented gingival areas three times daily. Receives: Drug: Licorice Extract Gel |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: Baseline, 4 weeks, 8 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).
Measured: Baseline, 4 weeks, 8 weeks, 12 weeks and 36 weeks
Secondary outcomes (2)
Participant Satisfaction
Participant satisfaction was assessed using a study-specific questionnaire consisting of four questions evaluating perceived esthetic improvement, fulfillment of expectations, self-confidence related to smile appearance, and willingness to recommend the treatment. Responses were recorded as categorical (non-numerical) variables, and no numerical scale was calculated. Outcomes were analyzed descriptively, with more favorable responses indicating higher satisfaction.
Measured: 3 months post-treatment
Postoperative pain intensity (laser group only)
Postoperative pain intensity was assessed in the diode laser group only using the Visual Analog Scale (VAS; range 0-10), where 0 indicates no pain and 10 indicates the worst imaginable pain. This outcome was not applicable to the licorice extract gel group due to the non-invasive nature of the intervention.
Measured: Immediately post-procedure, Day 1 and Day 7 postoperatively
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Jan 2026
- Study start1 Apr 2025
- Primary completion1 Jan 2026
- Study completion1 Jan 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Gingival HyperpigmentationStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- intervention (control group): Diode laser 445 nm intervention (test group): topical licorice extract gel
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 26 participants (actual)
Sponsor and investigators
- Lead sponsor
- Alexandria University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Rania Mostafa Eissa, Alexandria University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07325825
- Sponsor's protocol ID
- RaniaEissa-Dent-1999
- Status last verified
- Sep 2026
- First submitted
- 24 Dec 2025
- Last updated
- 10 Sep 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 10 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Comparative Evaluation of the Effectiveness of Topical Licorice Extract Gel and Diode Laser 445 nm on Physiologic Gingival Pigmentation
- ClinicalTrials.gov ID
- NCT07325825
- Acronym / sponsor ID
- RaniaEissa-Dent-1999
- Conditions
- Gingival Hyperpigmentation
- Keywords
- Gingival pigmentation, Diode laser, Licorice extract gel
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 26 participants (actual)
- Lead sponsor
- Alexandria UniversityUniversity, hospital or other
- Study start
- 1 Apr 2025 (actual)
- Primary completion
- 1 Jan 2026 (actual)
- Study completion
- 1 Jan 2026 (actual)
- First posted
- 8 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
This randomized controlled clinical trial will be conducted at the outpatient clinic of the Department of Oral Medicine, Periodontology, Oral Diagnosis and Oral Radiology, Faculty of Dentistry, Alexandria University, Egypt.
Eligible participants aged 18-50 years with physiologic gingival pigmentation will be randomly assigned into two groups. Group A will receive gingival depigmentation using a 445 nm diode laser, while Group B will receive topical licorice extract gel applied three times daily.
The intensity and distribution of gingival pigmentation will be evaluated using the Dummett-Gupta Oral Pigmentation Index (DOPI) and Gingival Pigmentation Index (GPI). Patient satisfaction will also be assessed. Clinical evaluations will be performed at baseline, 1 week, 4 weeks, 12 weeks and 36 weeks after treatment.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- intervention (control group): Diode laser 445 nm intervention (test group): topical licorice extract gel
| Arm | Type | Receives |
|---|---|---|
| Diode Laser Group | Active comparator | Device: Diode Laser 445 nmParticipants receive gingival depigmentation using a 445 nm diode laser. |
| Licorice Extract Gel Group | Experimental | Drug: Licorice Extract GelParticipants apply topical licorice extract gel to pigmented gingival areas three times daily. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- 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
Key exclusion criteria (8 listed)
- Smokers
- Pregnant or lactating females
- Patients taking drugs associated with gingival pigmentation
- Patients with periodontal disease
- History of gingival depigmentation
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Diode Laser 445 nmGingival depigmentation performed using a diode laser with a wavelength of 445 nm in continuous wave mode at 1 W power. | Device | Diode Laser Group |
| Licorice Extract GelTopical licorice extract gel applied to pigmented gingival areas three times daily for one month, with continuation for a second and third month if required. | Drug | Licorice Extract Gel Group |
Primary outcome
Change in gingival pigmentation intensity
Time frame: Baseline, 4 weeks, 8 weeks, 12 weeks and 36 weeks
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.
Change in gingival pigmentation distribution
Time frame: Baseline, 4 weeks, 8 weeks, 12 weeks and 36 weeks
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).
2 secondary outcomes
Participant Satisfaction
Time frame: 3 months post-treatment
Postoperative pain intensity (laser group only)
Time frame: Immediately post-procedure, Day 1 and Day 7 postoperatively
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 Sep 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Diode Laser 445 nm and Licorice Extract Gel in people with Gingival Hyperpigmentation, run by Alexandria University at 1 site in Egypt.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 10 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Egypt. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in gingival pigmentation intensity (time frame: Baseline, 4 weeks, 8 weeks, 12 weeks and 36 weeks). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Sep 2026.