Objectives: To compare upper lip frenulum reinsertion, bleeding, surgical time and surgical wound healing in frenectomies performed with the CO2 laser versus the Er, Cr:YSGG laser. Study design: A prospective study was carried out on 50 randomized pediatric patients who underwent rhomboidal resection of the upper lip frenulum with either the CO2 laser or the Er,Cr:YSGG laser. Twenty-five patients were assigned to each laser system. All patients were examined at 7, 14, 21 days and 4 months after the operation in order to assess the surgical wound healing. Results: Insertion of the frenulum, which was preoperatively located between the upper central incisors, migrated to the mucogingival junction as a result of using both laser systems in all patients. Only two patients required a single dose of 650 mg of paracetamol, one of either study group. CO2 laser registered improved intraoperative bleeding control results and shorter surgical times. On the other hand, the Er,Cr:YSGG laser achieved faster healing. Conclusions: Upper lip laser frenectomy is a simple technique that results in minimum or no postoperative swelling or pain, and which involves upper lip frenulum reinsertion at the mucogingival junction. The CO2 laser offers a bloodless field and shorter surgical times compared with the Er,Cr:YSGG laser. On the other hand, the Er,Cr:YSGG laser achieved faster wound healing. Key words:Frenectomy, upper lip frenulum, CO2 laser, Er,Cr:YSGG laser, laser.

Objective: The aim of this in vitro experimental study was to perform histological evaluation of the thermal effect produced on soft tissue irradiated with CO 2 , Er,Cr:YSGG or diode lasers. Study design: Porcine oral mucosa samples were irradiated with Er,Cr:YSGG laser at 1 W with and without water / air spray, at 2 W with and without water / air spray, and at 4 W with water / air spray, with CO 2 laser at 1 W, 2 W, 10 W, 20 W continuous mode and 20 W pulsed mode and diode laser at 2W, 5W, and 10W pulsed mode. The thermal effect was evaluated measuring the width of damaged tissue adjacent to the incision, stained positively for hyalinized tissue with Hematoxylin-Eosin and Masson Trichrome stains. Besides, histological changes in the irradiated tissue were described using subjective grading scales. Results: The evaluated lasers developed a wide range of thermal damage with significant differences between groups. The samples with lowest thermal effect were those irradiated with Er,Cr:YSGG laser using water / air spray, followed by CO 2 and diode lasers. Conclusions: Emission parameters of each laser system may influence the thermal damage inflicted on the soft tissue, however, the wave length of each laser determines the absorption rate characteristics of every tissue and the thermal effect.

Background The aim was to describe the recurrence rates of Oral Squamous Cell Papilloma (OSCP) following surgical treatment with surgical scalpel and two different lasers (CO2 or Er,Cr;YSGG) and to determine the clinical and histopathologic features of these lesions. Material and Methods A retrospective cohort study covering a period of 12 years (1997-2009) that included patients diagnosed of OSCP treated with surgical excision was performed. Data was processed using SPSS 22.0 (SPPS Inc. Chicago, USA) and a descriptive and bivariate analysis were conducted. Results A total of 37 histopathologically confirmed OSCP in 36 patients, 19 women (52.7%) and 17 men (47.2%) with an average age of 33.4 years (14-86 years) were included. Twenty-two cases were treated by excision with surgical scalpel excision, 11 with CO2 laser and 3 with Er,Cr:YSGG laser. The mean age was 35.4 years (14-86 years) and the distribution by gender was 19 women (52.7%) and 17 men (47.2%). The most common locations were the palate in 14 cases (37.8%), followed by the tongue in 11 cases (29.7%) and gingiva with 5 cases (13.5%). The average size of the lesions was 4.25 mm in diameter, with a mean evolution time of 5.9 months. The recurrence rate was slightly higher with the CO2 laser (14.3 %) in comparison with the conventional scalpel (10%). No recurrences for Er,Cr:YSGG were found. Conclusions No differences for recurrence rates for OSCP between groups were found. The recurrence rate is low, happening usually before 15 months of follow-up. OSCPs are lesions usually appearing in patients between 30 and 50 years of both genders and located predominantly on the palate, tongue and gingiva. Key words: Oral squamous cell papilloma, squamous cell papilloma, CO2 laser, recurrence.

Resumen: La utilización de la tecnología láser en Odontología ha tenido una constante evolución y desarrollo. Con este trabajo se pretende hacer una actualización desde un punto de vista crítico, científico y objetivo de los avances y aplicaciones que se han publicado sobre el láser de baja potencia en el ámbito de cada una de las especialidades odontológicas. Asimismo, se exponen sus características, las normas de seguridad necesarias para su utilización, sus efectos secundarios y sus contraindicaciones.Palabras clave: Láser de baja potencia, Láser terapéutico, Odontología. Abstract:The use of laser devices in dentistry has undergone a constant evolution and development. The aim of this work is the critical review, from a scientific and objective point of view, of the latest advances and applications reported in the literature regarding low level laser therapy applied to the different dental specialties. Besides, their main features, security advice on its use, adverse effects and contraindications are exposed.

Objectives. A study was made to determine the temperature increment at the dental root surface following Er,Cr:YSGG laser irradiation of the root canal. Design. Human canines and incisors previously instrumented to K file number ISO 30 were used. Irradiation was carried out with glass fiber endodontic tips measuring 200 µm in diameter and especially designed for insertion in the root canal. The teeth were irradiated at 1 and 2 W for 30 seconds, without water spraying or air, and applying a continuous circular movement (approximately 2 mm/sec.) in the apico-coronal direction. Results. At the 1 W power setting, the mean temperature increment was 3.84ºC versus 5.01ºC at 2 W. In all cases the difference in mean value obtained after irradiation versus the mean baseline temperature proved statistically significant (p< 0.05). Conclusions. Application of the Er,Cr:YSGG laser gives rise to a statistically significant temperature increment at the external root surface, though this increment is probably clinically irrelevant, since it would appear to damage the tissues (periodontal ligament and alveolar bone) in proximity to the treated tooth.