A Phase 3 interventional study of Topical application of ascorbic acid for treatment of gingival pigmentation and Topical application of liquid nitrogen for treatment of gingival pigmentation in Gingival Pigmentation and Gingiival Hyperpigmentation, sponsored by Al-Azhar University. Enrolling by invitation at 1 site in Egypt. Open to participants aged 18 Years to 40 Years. Per ClinicalTrials.gov, last updated 2026-09-09.
Sponsored by Al-Azhar University · Phase 3, Interventional, and Treatment
Aim of study The present study will be designed to evaluate the clinical and histomorphometric outcomes of using topical liquid nitrogen and topical ascorbic acid in gingival depigmentation.
Primary outcome:
Secondary outcome:
Gingival hyperpigmentation is caused by excessive deposition of melanin in the basal and parabasal cell layers of the epithelium, it's mainly physiological due to the production of melanin. One of the factors that determines the colour of the gingiva is the amount of melanin pigment in the gingival epithelium. The intensity of melanin pigmentation differs from one person to another, and it is prevalent among all ethnicities. Gingival melanin pigmentation may cause esthetic concerns, even if no serious medical problem is present.
Gingival depigmentation can be defined as a periodontal plastic surgical procedure whereby the gingival hyperpigmentation is removed or reduced by various techniques. Depigmentation is not a clinical indication but a treatment of choice where esthetics is a concern and is desired by the patients.
A variety of depigmentation techniques can be classified into the following groups: surgical methods (Conventional techniques) as gingival abrasion and split thickness epithelial excision/scalpel, surgical technique/surgical stripping, electrosurgery, lasers, cryosurgery with liquid nitrogen, radiosurgery, and chemical methods using agents such as alcohols, phenols, and ascorbic acid.
Vitamin C, known as ascorbic acid, is used as a treatment modality in depigmentation of hyperpigmented spots on the skin and gingiva by inhibition of tyrosinase enzyme causing melanin biosynthesis suppression.
Vitamin C interacts with the copper (Cu) ions at the tyrosinase active site and inhibits the action of the enzyme tyrosinase, thereby reducing melanin formation. It also acts on the perifollicular pigment. However, it is an unstable compound. Therefore, it is used in combination with soy and liquorice for depigmentation in dermatology.
Advantages of cryotherapy include being a bloodless treatment, very low incidence of secondary infection and with a relative lack of scarring and pain. It provides a very good esthetic result and may be either the first choice or an alternative option to conventional surgery.
Cryotherapy with liquid nitrogen is the deliberate destruction of tissue by application of extreme cold that leads to freezing of pigmented cells.
Exclusion Criteria:
Drug: Topical application of ascorbic acid for treatment of gingival pigmentation
Combination Product: Topical application of liquid nitrogen for treatment of gingival pigmentation
Procedure: Treatment of gingival pigmentation by surgical technique
topical application of ascorbic acid (non surgical technique ) for treatment of gingival pigmentation
Topical application of liquid nitrogen (non surgical technique ) for treatment of gingival pigmentation
conventional technique for treatment of gingival pigmentation
Clinical severity of gingival pigmentation
DOPI index of gingival pigmentation (Dummett-Gupta Oral Pigmentation Index) sores the intensity of gingival pigmentation with scores ranges from 0 to 3, 0 = no pigmentation (pink gingiva) and 3 = heavy pigmentation (deep brown / blue - black gingiva).
Time frame: 3 month follow up
Clinical severity of gingival pigmentation
DOPI index of gingival pigmentation
Time frame: 3 month follow up
Histologic assessment of the melanin forming cells
Histologic assessment of the melanin forming cells by Hematoxylin and Eosin (H\&E) stain to veiw the melanocytes and the melanin pigentation in epithelium.
Time frame: 3 month follow up
Plan to share: No
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Al-Azhar University