Resumen de Comparative Evaluation of Photoablative Efficacy of Erbium: Yttrium-Aluminium-Garnet and Diode Laser for the Treatment of Gingival Hyperpigmentation. A Randomized Split-Mouth Clinical Trial
Background: The use of lasers in periodontology is a matter of debate, mainly because of the lack of consensual therapeutic protocols. In this randomized, split-mouth trial, the clinical efficacy of two different photoablative dental lasers, erbium:yttrium-aluminum-garnet (Er:YAG) and diode, for the treatment of gingival hyperpigmentation is compared.
Methods: Twenty-one patients requiring treatment for mild-to-severe gingival hyperpigmentation were enrolled. Maxillary or mandibular left or right quadrants were randomly subjected to photoablative deepithelialization with either Er:YAG or diode laser. Masked clinical assessments of each laser quadrant were made at admission and days 7, 30, and 180 postoperatively by an independent observer. Histologic examination was performed before and soon after treatment and 6 months after irradiation. Patients also compiled a subjective evaluation questionnaire.
Results: Both diode and Er:YAG lasers gave excellent results in gingival hyperpigmentation. However, Er:YAG laser induced deeper gingival tissue injury than diode laser, as judged by bleeding at surgery, delayed healing, and histopathologic analysis. The use of diode laser showed additional advantages compared to Er:YAG in terms of less postoperative discomfort and pain.
Conclusions: This study highlights the efficacy of diode laser for photoablative deepithelialization of hyperpigmented gingiva. It is suggested that this laser can represent an effective and safe therapeutic option for gingival photoablation.
Physiologic gingival hyperpigmentation (PGH), caused by excessive melanin deposition by melanocytes mainly located in the basal and suprabasal cell layers of the epithelium,1 affects numerous people of different ethnic backgrounds.2 Although PGH is definitely benign and does not represent a health concern, complaints of dark gums are common, particularly among individuals with excessive gingival display during smiling or talking, which compels them to seek appropriate cosmetic treatment. Gingival depigmentation has been performed using various methods and techniques, including mechanical abrasion,3 surgical removal,4,5 cryosurgery or electrosurgery,6-8 and chemical etching,9 with different degrees of success. Moreover, some of these techniques are prone to side effects and complications. In recent years, the use of laser photoablation has been recognized as one of the most effective, pleasant, and reliable techniques for this purpose.10 The commonly used lasers for gingival deepithelialization include semiconductor diode,11 erbium: yttrium-aluminium-garnet (Er:YAG),12 neodymium:yttrium-aluminum-garnet (Nd:YAG),13 and CO2.13,14 High-power lasers (CO2, Nd:YAG, diode ? 810 to 980) are preferred for soft-tissue surgery because they cause tissue ablation/vaporization, hemostasis, and sterilization.13,14 Instead, Er:YAG laser is commonly used to target hard tissues, such as bone, enamel, cementum, and dentin, and it is recently gaining importance and interest for gingival deepitelization.15 Recent research has centered on pulsed diode laser (? 810) used in photoablative mode in periodontal surgery; this has been primarily used for oral surgery of the tongue and gingiva and in chronic periodontitis to remove the infected epithelium inside and around periodontal pockets.16 Indeed, this laser has some advantages compared to the others, such as easier gingival reshaping, reduced need for local anesthesia, excellent hemostasis, minimal thermal injury of the deeper tissues, and negligible postoperative pain and inflammation.16,17 All these characteristics may also be important in the use of diode laser for cosmetic purposes, including the removal of benign gingival hyperpigmentation. In keeping with this hypothesis, there is evidence in the recent literature of successful depigmentation using diode lasers.10,18,19 In the present study, the authors want to further expand the knowledge on the issues discussed above by analyzing and comparing the effects of a diode laser (? 810 nm) and an Er:YAG laser (? 2,940 nm) on gingival depigmentation in terms of the following: 1) clinical outcome in the short term and midterm (up to 6 months of follow-up); 2) histologic response of gingival tissues to laser photoablation; and 3) patients� discomfort during treatment and preference for either treatment modality.
