Eligibility Criteria:
Inclusion Criteria:
* Systemically healthy individuals
* Absence of pathological gingival pigmentation
1. Group A - Healthy Periodontium: Absence of clinical signs of inflammation like bleeding on probing, erythema, edema, attachment loss, bone loss, patient symptoms, (bone levels at 1-3mm apical to CEJ)
2. Group B - Gingivitis: Presence of cardinal signs of inflammation along with, bleeding and discomfort on gentle probing, loss of knife-edged margin and blunting of papilla,
3. Group C - Periodontitis: Presence of cardinal signs of inflammation along with, bleeding and discomfort on gentle probing, loss of knife-edged margin and blunting of papilla,periodontal pocketing, clinical attachment loss, radiographically assessed bone loss
Exclusion Criteria:
* Tobacco associated pigmentation - smoker's melanosis, chewing/ pouching tobacco
* Pigmentation from exogenous pigments - amalgam tattoo, cultural tattooing, beverages, food colours, betelnut/khat chewing, heavy metals ( mercury, silver, arsenic, bismuth, graphite, lead), topical medications, other foreign bodies
* Pigmentation from endogenous pigments - jaundice, ecchymosis/ petechiae, haemochromatosis, hemosiderin
* Long term consumption of pigmentation causing drugs - ACTH, antimalarial drugs, busulfan, doxorubicin, minocycline, oral contraceptives, phenothiazies
* Syndromes and systemic diseases associated with pigmentation - Addison's disease. Albright's syndrome, basila melanosis, β-thalassemia, healed / healing mucocutaneous lesions, hereditary hemorrhagic Telangiectasia, HIV-associated melanosis, Neurofibromatosis, Peutz Jeghers syndrome, hamartoma, pyogenic granuloma, epulis
* Benign or malignant lesions involving gingival - angiosarcoma, hemangioma, Kaposi's sarcoma, malignant melanoma, melanocytic nevus, pigmented vaculoe