Key words:
Depigmentation - diode laser - gingiva - melanin
Introduction
Melanin is a brown pigment, located in basal and suprabasal layers of gingival epithelium.[[1]] It plays a main role in physiologic gingival pigmentation which is also determined by the thickness of epithelium, presence of blood vessels, and epithelium keratinization degree. Physiologic pigmentation is mainly genetically determined; however, some other factors such as activity of endocrine glands, ultraviolet radiation, smoking, and medication can also cause gingival hyperpigmentation.[[2]] It is a real esthetic concern for most of the individuals, especially in the anterior keratinized gingiva of the maxilla and mandible.
For depigmentation of gingiva, different techniques have been used such as rotary instruments, scalpel technique, electrosurgery, and different types of lasers.[3],[4] Each technique has its own advantages and disadvantages. In addition to carbon dioxide and erbium: yttrium-aluminum-garnet lasers, diode lasers with different wavelengths have also been commonly used with no side effects.[5],[6]
In this case series, the use of 810 nm diode laser for gingival depigmentation caused by smoking is presented.
Case Report
Two female patients aged 28 and 25 years with a chief complaint of “darkened gums” visited private practice. Both the patients were systemically healthy and not under any medication. They have been smoking more than one pack of cigarette every day for more than 10 years. In clinical examination, periodontal tissues were healthy, but bilateral melanin pigmentation wa present in both the maxilla and mandible [Figure 1]. Dummett-Gupta oral pigmentation (DOP) index[[7]] was used to determine the level of depigmentation, and the score was diagnosed as “4” for both of the patients (1: no clinical pigmentation, 2: mild clinical pigmentation, 3: moderate clinical pigmentation, and 4: heavy clinical pigmentation).
Figure 1: Baseline
Under local anesthesia, depigmentation procedure was applied by 810 nm wavelength diode laser (Cheese® Wuhan, China). The fiber-optic laser tip having a 400 ^m diameter at 1.3 W power in continuous mode was kept in contact with the pigmented area. Depigmentation was performed in a horizontal direction, using the laser tip in contact mode on the pigmented part of the gingiva and parallel to the root surfaces not to cause overheating, and the area depigmented was wiped with gauze soaked in saline [Figure 2]. After the procedure, no periodontal dressing was applied and no antimicrobials were prescribed. Patients were instructed to avoid smoking and hot, acidic, and spicy food that can jeopardize the healing process and cause patient discomfort. Following depigmentation, patients were recalled at weeks 1, 4, and 12 during postoperative period for clinical evaluation and repigmentation rate.
Figure 2: Depigmentation by diode laser
Patients mentioned a mild sensitivity only at the day of the surgery. No postoperative pain, hemorrhage, or scarring was observed in both patients, and the healing was uneventful. At week 1, gingiva showed a rapid but immature epithelialization. On the final healing at 12 weeks, gingiva appeared pale pink which was satisfactory for both patients and operator [Figure 3]. DOP index for both patients was scored as “1.”
Figure 3: Complete healing 12 weeks after depigmentation
Discussion
The degree of melanin pigmentation depends on the number and distribution of melanocytes and their capacity to transfer melanin and melanin uptake by keratinocytes.[[8]] Melanin-pigmented gingiva is often a demand for depigmentation mainly for esthetic reasons. Different techniques have been used for this procedure such as scalpel technique, cauterization, cryotherapy, diamond burs, and lasers, the latter being the most recent and reliable one.[9]-[11] To date, many wavelengths of the lasers are suggested to beneficial in melanin depigmentation procedure. However, all of the published studies employed a different set of irradiation parameters.[[12]] In this study, we used 810 nm diode laser to remove melanin pigmentation in the anterior region of both the maxilla and mandible of patients.
Melanocytes, located in mostly basal and suprabasal layers of gingival epithelium, should be eliminated for a proper depigmentation. Superior to other techniques, application of a laser results in homogeneous ablation of epithelial and rete pegs as well. Diode laser with 810 nm wavelength is used in soft tissues for coagulation and cutting. Diode laser irradiation also has bactericidal effect resulting in hemostasis.[[13]] Having a high affinity to penetrate into hemoglobin and melanin pigments makes it the preferred laser for depigmentation of gingiva. Diode lasers can be used both in pulsed or continuous mode. Application of the laser in pulsed mode prevents overheating of surrounding tissues that may cause necrosis and jeopardize healing. Taking into consideration the previously published studies,[3],[4],[14],[15] diode laser was used in continuous mode in this study knowing the fact that it may penetrate deeper and affect connective tissue as well. That’s why, the evaluations were also made at weeks 4 and 12. The use of lasers has several advantages such as no need to place a periodontal dressing, short healing period, no or very slight pain, no hemorrhage. The only disadvantage may be the high cost of the lasers.
Repigmentation may also occur depending on the technique used and the race of the patients.[[16]] According to the theory, melanocytes migrate from the adjacent pigmented tissues to treated sites resulting in repigmentation.[[17]] It is an outcome of histologic changes in the melanocyte activity and density of melanin pigments that can be seen from 15% to 30% even after 6 months of depigmentation.[[18]] It is important to remove as much melanocytes as possible in order to prevent them to migrate from periphery.
That’s why, it may be beneficial for a clinician to use magnifications during the procedure. In this study, patients were followed up for 3 months, and no repigmentation was observed during that time. However, the reason for this result may be the short follow-up period as the histological changes may vary depending on the race and technique used.
In this case series, the use of 810 nm diode laser for depigmentation of gingiva resulted in complete healing at week 12. It was also shown to be a safe and effective method for acceptable esthetic result and maximum patient comfort. A longer follow-up of the patients is necessary to monitor the occurrence of repigmentation.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Nil.
