Ascorbic Acid Versus Diode Laser in the Treatment of Gingival Hyperpigmentation

Inclusion Criteria: * Male and female patients with age ranging from 18 years old to 40 years old. * Bilaterally symmetric gingival hyperpigmentation on the maxillary and mandibular labial keratinized gingiva between canines. * Patients free from any systemic diseases as evidenced by the health questionnaire, using modified Cornell medical index (Pendleton et al., 2004). * Patients with thick gingival biotype ≥ 3 mm. Exclusion Criteria: * Presence of local condition that may cause gingival hyperpigmentation (traumatized epithelium caused by defective fixed prosthesis or restoration). * Smokers. * Pregnant or lactating females. * Patients with poor oral hygiene, incompliance to treatment and persistence gingival inflammation after phase I periodontal therapy. * Clinically diagnosed periodontitis (attachment and bone loss, presence of periodontal pockets, gingival recession and tooth mobility). * Previous treatment to pigmentation. * Patients taking supplementary vitamin C for any reason. * Known sensitivity to ascorbic acid or any of its derivatives. * Patients taking any drug that may cause gingival pigmentation.