The present study will be carried to clinically evaluate the efficacy of microneedling with vitamin C in performing gingival depigmentation in comparison with conventional scalpel and diode laser.

Gingival depigmentation can be considered a periodontal plastic procedure, whereby the gingival hyperpigmentation is removed by various techniques where the technique selection should primarily be based on clinical experiences and individual preferences with primary indication of demand for improved esthetics. Different techniques for depigmentation include: Scalpel technique, Cryosurgery, Electrosurgery, Lasers as neodymium-doped yttrium aluminum garnet (Nd: YAG), Erbium-doped yttrium-aluminum-garnet (Er: YAG) laser, Carbon dioxide laser CO2 and diode laser. also, Chemical methods including acoustic agents (not used nowadays) was used for treatment of gingival pigmentation. Other methods as free gingival graft and acellular dermal matrix allograft can also be used where the aim is masking the pigmented gingiva. Diode laser is a high-power semiconductor laser that emits energy at a wavelength between 800 and 1000 nm. It has an affinity for hemoglobin and melanin; therefore, it is more efficient and better equipped to address deeper soft tissue problems. It is indicated for cutting and coagulatinggingiva and oral mucosa, creating zones of thermal necrosis of less than 1 mm and hemostasis of the affected mucosa. It has been reported as effective, pleasant and reliable method with minimal postoperative discomfort, less bleeding, low recurrent rate and faster wound healing for depigmentation procedure. The light of this laser is emitted through synthetic sapphire tips in contact mode then transmitted to optical fibers to etch or vaporize soft tissues. Vitamin C , also known as ascorbic acid, is a water-soluble vitamin that has significant antioxidant properties that protects cells from free radical damage. In addition, vitamin C also nurtures the growth and repair of skin, cartilage, bone, and teeth. Vitamin C was reported to be effective in reducing melanogenesis directly and thus promoting depigmentation. This is accomplished by interacting with tyrosinase, leading to the suppression of tyrosinase enzyme activity and, consequently, a reduction in melanin production. Vitamin C affects melanocyte function rather than the number, when compared with other approaches that relying on the destruction of melanocytes. The food and drug administration (FDA) has legally authorized microneedling (MN) devices to improve the appearance of facial acne scars, facial wrinkles, and abdominal scars. However, there are various types of MN devices including dermaroller, dermastamp, and dermapen. Dermapen is the only device that can be applied intraorally due to its small size and changeable head. This increases the accessibility inside the mouth and makes it easy to be used for a larger number of patients. This device is a wireless electric device with automated features that allow the operator to modify the speeds, pressures, and depth of penetration. It was necessary to generate precise bleeding pinpoints by MN to achieve optimal results. These microholes allow the therapeutic medication to penetrate easily into the connective tissues, stimulating new collagen production and affecting melanocytes.

Inclusion Criteria:

1. Patients with bilateral, diffuse and symmetric physiologic gingival pigmentation in the labial maxillary or mandible gingiva.
2. Patients free from any systemic diseases according to criteria of Modified Cornell Medical Index. (Abramson J et al., 1966)
3. Periodontally healthy patient.
4. Patients with age between 18 and 50 years

Exclusion Criteria:

1. Smokers.
2. Drugs intake "mainly those associated with gingival pigmentation".
3. Pregnant and lactating women.
4. Patients with thin gingival phenotype "with scalpel group".
5. Gingival pigmentation associated with occupational hazards.
6. Individuals undergoing chemotherapy