Physiologic gingival pigmentation(PGP) is the most common type of gingival pigmentation and cosmetic concern particularly in gummy smile patients. Laser therapy is an effective and noninvasive treatment option. The aim of this study was to evaluate the efficacy of diod laser on the treatment of PGP in patients.

Preoperative and postoperative photographic and clinical observations about the gingival melanin pigmentation were made according to Dummett-Gupta Oral Pigmentation Index scoring criteria given by Dummett C.O. in 1964 The investigators classified pigmented gingiva in patients as:

1. Mild:Pink to slightly brown
2. Moderate:Deep brown or black
3. Severe:Mixed in color Score in each tooth was taken including one full inter dental papilla. Observations were made in natural light. The assessment of the scoring of the pigmentation index were done by all the three examiners, and the agreed upon score was assigned to prevent individual variations.

The investigators compared the intensity of pigmentation in each patient in recall sessions after 1month and 3mounth postoperative.

Inclusion Criteria:

• 19 adult patients who had been referred to oral medicine department of Shahid Beheshti dental school with the chief complaint of melanin pigmentation were selected for inclusion in this study.

Exclusion Criteria:

1. Hyperpigmentation that was associated with systemic disease or drug administration,disease that could compromise wound healing (uncontrolled diabetes, autoimmune disease)
2. Pregnancy or lactation
3. Evidence of relationship between hyperpigmentation and malignancy
4. History of previous treatment of hyperpigmentation
5. Smoking
6. Periodontal problems