A 27-year-old Caucasian female was referred to the Stomatology and Dental Medicine Department (CESPU) of the Centro Hospitalar de São João, Pólo de Valongo, Oporto, Portugal. Her chief complaint was of a “dark-colour lower gum” and she made the request for rapid cosmetic therapy. She reported noticing darkening of the teeth and gums for over two years, mainly in the mandible. No symptoms and no significant personal or family history were present. The patient denied taking any medication or any other dark pigmentation in other locations. Her blood pressure was within the normal range of values. She had stopped smoking a year before the consultation, although she had smoked 30 cigarettes per day for more than 10 years. On oral examination two black-brown macules measuring 1 × 1 cm were detected in the vestibular attached lower gingiva (). There was no lymphadenopathy or salivary gland abnormalities detected. Previous incisional biopsy to rule out any malignancy and blood investigations (complete full blood count and general biochemistry, including cortisol and ACTH serum levels) showed no abnormalities or potential causes. A diagnosis of smoker's melanosis was given based on the smoking history and the absence of any abnormalities seen in previous investigations. After explaining the benign character of the pigmentation, the patient requested the elimination of the pigmentation by aesthetic reasons due to professional work issues. A CO2 laser vaporization for gingival depigmentation was proposed. The vaporization of the pigmentation was performed under local anaesthesia (2% lidocaine with 1 : 100,000 epinephrine) with CO2 laser (10600 nm) (DEKA Smart US20D, Florence, Italy), with angulated mirror, focus spot of 1 mm, pulsed mode (50 Hz), 4.5 W of output power, power density of 573.25 W/cm2, and fluence of 11.46 J/cm2 (). During this procedure, safety precautions were in place to protect the operator, assistant, and patient. With this laser procedure, the secondary-intention healing of the surgical wound was reached without any dressing (). Paracetamol (1 g every 12 hours) was prescribed for two days to be taken only if she developed painful symptoms. After 3 weeks, wound healing was completed uneventfully without any melanin pigmentation (). She did not report any postoperative pain, swelling, or other complications. After two years of follow-up, the patient had no symptoms or signs of gingival melanin pigmentation.
A 9-year-old boy was referred to the Department of Pediatric Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran. The patient needed comprehensive dental treatment due to amelogenesis imperfecta. At the same time his parents requested to treat his gingival pigmentation. His oral examination revealed that his gingiva is deeply pigmented from the right second primary molar to the left second primary molar (). He had been checked by a physician previously and there were no pathologic disorders (e.g. Albright syndrome, trauma, hemachromatosis and racial pigmentation) in this case. Therefore, we started depigmentation therapy by cryosurgery technique.\nLiquid nitrogen was provided in the morning of treatment day by a consumer gas factory and was transferred to the dental facility. In order to transfer the liquid nitrogen, it had been saved in a two-layer flask (metallic inner layer and glassy outer layer).\nIn the first step isolation was instated by suction and cotton rolls; then hyperpigmentation areas were dried byair spray and 10% topical lidocaine gel was used to achieve anesthesia. During treatment, liquid nitrogen was poured into the glass mug and was rolled on the pigmentation area by cotton swabs (). After the gingiva blanched, the operation was started in another area; after 20 seconds this process was repeated. It is possible repeat this process three or four times for each area. The total time needed for this operation was 30 minutes. In order to record and analyze the results, five standard photos were taken in different positions. Standard high-quality images were taken at baseline and after one, three, six and twelve months (). All the photos were taken by a Canon digital camera (Ixus 800IS, Japan) in the same position, while the patient was sitting upright, and the distance between patient and camera was fixed to about 30 centimeters.\nMinimal reddish erythema was observed after cryosurgery. After one month the gingival color was ideal. No complications were observed during the follow-up. No recurrent lesions were observed in 12-month follow-up ().