Evaluation of the Efficacy of Topical Application of Liquid Nitrogen and Ascorbic Acid in Treatment of Gingival Pigmentation

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.

Inclusion criteria

• Individuals with mild-to-severe anterior melanin gingival pigmentation in the anterior portion of the upper and lower gingiva according to Dummet's classification will be involved.
• The patients included in this study will be Type 1 individuals according to American Society of Anesthesiology .
• The age of the patients ranges between 18 and 40 years.

Exclusion criteria

• smoker patients
• pregnant and lactating women
• patients with any systemic disease that may induce the production of melanin
• patients with periodontal disease, non vital anterior teeth
• patients with known hypersensitivity to ascorbic acid
• patients who had previous depigmentation procedures.