The normal colour attributed to gingiva is coral pink or salmon pink, with physiological variations of melanin pigmentation. The cosmetic expectations have increased with time and current trends speak volumes about gingival esthetics and smile designing. Gingival pigmentation especially on the labial aspect of anterior teeth has become an important component of general esthetics. Pigmentation is both the normal and abnormal discoloration of oral mucous membrane. Pigmentation has multifactorial etiology. Most of the pigmentation is physiologic but sometimes it can be a precursor of severe diseases. Gingival hyperpigmentation are major concerns for a large number of patients visiting the dentist. Melanin hyperpigmentation usually does not present a medical problem, but patients usually complain of dark gums as unaesthetic. On studying the clinical, etiology and histopathological features of pigmentation and its differential diagnosis it is revealed that aesthetic concern requires removal of pigmented gingival areas to create a pleasant and confident smile. Oral melanin pigmentation can be eliminated by a variety of surgical techniques, including free gingival grafts and soft tissue allografts and de-epithelialization by bur abrasion, scalpel, laser and cryosurgery. However, randomized controlled longitudinal studies are needed to establish the efficacy and applicability of these techniques.
Source: Gingival Pigmentation: Revisited, Journal of Advanced Medical and Dental Sciences Research, 2016; Vol 4, Issue 1 http://jamdsr.com/uploadfiles/10.pigmentation-2.20160123095052.pdf