RESUMO

This work reports the modification in the homogeneity of ablation effects with the assistance of nonlinear optical phenomena exhibited by C. albicans ATCC 10231, forming a biofilm. Equivalent optical energies with different levels of intensity were irradiated in comparative samples, and significant changes were observed. Nanosecond pulses provided by an Nd:YAG laser system at a 532 nm wavelength in a single-beam experiment were employed to explore the photodamage and the nonlinear optical transmittance. A nonlinear optical absorption coefficient -2 × 10-6 cm/W was measured in the samples studied. It is reported that multiphotonic interactions can promote more symmetric optical damage derived by faster changes in the evolution of fractional photoenergy transference. The electrochemical response of the sample was studied to further investigate the electronic dynamics dependent on electrical frequency, and an electro-capacitive behavior in the sample was identified. Fractional differential calculations were proposed to describe the thermal transport induced by nanosecond pulses in the fungi media. These results highlight the nonlinear optical effects to be considered as a base for developing photothermally activated phototechnology and high-precision photodamage in biological systems.

RESUMO

Bismuth titanate (BTO) nanoparticles were obtained by pulsed laser ablation in liquid media (PLAL). Distilled water, ethanol, isopropanol, and acetone were used as media for laser ablation experiments, in which the colloidal solutions were obtained. Laser ablation was carried out using the second harmonic and fundamental wavelength of a pulsed Nd:YAG laser (532 nm and 1064 nm, respectively) with laser fluences of 25 and 12 mJ/cm2, respectively. Transmission electron microscopy was utilized for morphological characterization. BTO nanoparticles obtained have spherical shapes with orthorhombic structure and the average size distribution depended on the liquid media nature. In alcohols, BTO NPs were spherical with a carbon layer around them. X-ray diffraction, UV-Vis absorption spectra, and X-ray photoelectron spectroscopy were used to confirm the structural, optical, and elemental properties of the ablated products. The presented results show that PLAL is a viable technique for the synthesis of high-quality BTO nanoparticles with enhanced optical properties for possible applications in photocatalysis.

RESUMO

Ankyloglossia is considered a congenital patology, whose treatment indicated is a frenectomy, this surgical technique consists in remove the tissue that joins the tongue with the floor mouth. This technique allows the patient a considerable improvement to limitations caused by this anomaly such as difficulties in suction, pronunciation, chewing and difficulty in touching the lower lip with the tip of the tongue. Currently the use of laser technology and its benefits in modern dentistry, allows the realization of surgical procedures free of bleeding, with very little pain and inflammation of the tissues and with a recovery time much lower than necessary with conventional techniques. The present clinical case, show a 12-year-old patient with severe ankyloglossia, lingual frenectomy was indicated. A contact Nd: YAG laser was used, achieving a surgical intervention with little pain, free bleeding and without suture.

RESUMO

Una de las causas de la disminución de la visión es la catarata. El tratamiento es la extracción del cristalino opaco con reemplazo por un lente intraocular (LIO). La opacidad de cápsula posterior (OCP) es una complicación frecuente a largo plazo. Las modificaciones en el diseño del LIO tanto del material y la forma tienen mayor importancia para prevenir la OCP. Como tratamiento está la capsulotomía neodimio YAG láser. Objetivo: identificar la OCP relacionado con el tipo de LIO implantado en pacientes pseudofáquicos en la FBO, entre el periodo de marzo del 2019 hasta febrero del 2022. Métodos: estudio observacional, tipo analítico, subtipo cohorte histórica, retro- prospectiva y longitudinal, con enfoque de análisis estadístico de tipo cuantitativo. Resultados: predominó el género femenino con un 60 % y un 40 % representaba al masculino; un 60,3 % del total tenían entre 65 a 80 años. La OCP en los 3 tipos de lentes intraoculares (acrílico y PMMA) ocasionó una disminución en la agudeza visual: el 37 %, predominó, por el LIO hidrofóbico, 36 % por el LIO PMMA y destacamos que el 27 % fue por el LIO hidrofílico. La incidencia de OCP a 5 años fue del 32 %. No se registró ningún efecto adverso en nuestro estudio. Conclusiones: la OCP provoca una baja de agudeza visual leve a moderada en los 3 tipos de LIOs; con un mínimo predominio de BAV leve para el tipo de LIO hidrofóbico comparado con el hidrofílico. Además después de la capsulotomía un gran porcentaje tiene entre 20/20 a 20/25 de AV mejor corregida.

One of the causes of decreased vision is cataract. Treatment is removal of the cloudy lens with replacement by an intraocular lens (IOL). Posterior capsule opacity (PCO) is a common long-term complication. Modifications in the design of the IOL both in terms of material and shape are of greater importance in preventing PCO. Treatment is neodymium YAG laser capsulotomy. Objective: to identify the PCO related to the type of IOL implanted in pseudophakic patients in the FBO, from March 2019 to February 2022. Methods: observational study, analytical type, historical cohort subtype, retro-prospective and longitudinal, with a quantitative statistical analysis approach. Results: the female gender predominated with 60% and 41% represented the male; 60.3% of the total was between 65 and 80 years old. PCO in the 3 types of intraocular lenses (acrylic and PMMA) caused a decrease in visual acuity: 37%, predominated, due to the hydrophobic IOL, 36% due to the PMMA IOL and we highlight that 27% was due to the hydrophilic IOL. The incidence of PCO at 5 years was 32%. No adverse effect was recorded in our study. Conclusion: PCO causes mild to moderate visual acuity loss in all 3 types of IOLs; with a minimal predominance of mild AVB for the hydrophobic IOL type compared to the hydrophilic one. In addition, after capsulotomy, a large percentage has between 20/20 and 20/25 better corrected visual acuity.

RESUMO

OBJECTIVES: To evaluate the effect of Nd:YAG laser irradiation as a prior desensitizing strategy on immediate and medium-term microtensile bond strength (µTBS) to simulated hypersensitive dentin. MATERIALS AND METHODS: Flat mid-coronal dentin was obtained from third molars and submitted to a 600-grit SiC paper (1 min; N: normal dentin) or subsequently challenged with citric acid (6%, 1 min; H: simulated hypersensitive dentin). Afterwards, dentin was or was not (C: control; HC, NC - each n = 7) irradiated with Nd:YAG laser (L: laser; 1.0 W/10 Hz/100 mJ/4 irradiations of 50-60 s; HL, NL - each n = 7). A 2-step self-etch adhesive (Clearfil SE Bond) was applied and composite (Filtek Z350) buildups were constructed. After 24-h (distilled water/37 °C) storage, specimens were sectioned into beams and tested (µTBS; 0.5 mm/min) immediately or after 6-month aging. Three-way ANOVA and Tukey tests were applied (α = 0.05). Qualitative evaluation of the adhesive interface (n = 1 extra tooth per group) was performed by Confocal Laser Scanning Microscopy. RESULTS: Substrate condition (p < 0.001), laser irradiation (p < 0.001), and aging (p = 0.002) influenced the results. Furthermore, there was interaction between substrate and irradiation (p < 0.001). Laser irradiation favored µTBS exclusively to hypersensitive dentin immediately and after aging. µTBS to hypersensitive dentin was higher than that to the normal substrate only when it was laser-irradiated. In any case, immediate µTBS was always higher than that after aging. CLSM revealed longer and more numerous resin tags for simulated hypersensitive dentin, and shorter and fewer resin tags for laser-irradiated dentin. No differences were observed in the hybrid layer itself. CONCLUSION: Nd:YAG laser irradiation prior to restoration favored the µTBS of a self-etch adhesive and resin composite to hypersensitive dentin. CLINICAL RELEVANCE: Desensitizing strategies are usually tried before performing restorative treatments in hypersensitive dentin; therefore, they may influence behavior of the adhesive interface established. However, instead of causing concern, Nd:YAG laser irradiation revealed a favorable effect on the aforementioned interface.

Assuntos

RESUMO

Introduction: Although tattoos are ancient and very popular among young people, it is also a reason for regret, and many people today have a desire to remove them. Among the possibilities for this, laser removal is the most successful procedure with the highest degree of pigment removal and the lowest risk of complications. Methods: This study was recorded on three patients with tattoos, and only the black pigments were removed. None of the patients involved had a history of skin allergies, skin cancer, and/or keloid formation. Case 1 had a professional tattoo removed in the right calf region in two sessions. Case 2 had an amateur tattoo that was removed on the scalp in three sessions. Finally, Case 3 had two professional tattoos, which were removed from the face in a total of eleven sessions. The following equipment was used: Spectra XT Q-Switched Nd:YAG 1064 nm with a pulse width of 5 ns; Pico Ultra 300 Nd:YAG 1064 nm with a pulse width of 300 ps; and SoftLight Q-Switched Nd:YAG 1064 nm with a pulse width of 17 ns. Results: In general, satisfactory results were obtained, but hypopigmentation was present in Cases 1 and 3. This was probably due to sun exposure at the laser removal site, the short interval between the sessions, and/or higher radiant exposure combined with a smaller spot size, respectively. Conclusion: To achieve a successful tattoo removal in the higher phototypes and reduce unwanted effects, the professionals must know the best parameters to be used, as well as the adequate foundation on the individual characteristics of each patient and the tattoos. Furthermore, patient compliance with the pre/post session care and a suitable interval between the laser sessions are essential to avoid undesirable complications.

RESUMO

El síndrome de contracción capsular se describe como una reducción progresiva y acelerada del diámetro de la capsulorrexis y del saco capsular tras la extracción extracapsular del cristalino. Se reporta el caso de una paciente femenina, con antecedentes de miopía elevada, a quien se le realizó cirugía de catarata de ambos ojos sin complicaciones transquirúrgicas, y regresa con síndrome de contracción capsular bilateral al mes de operada. Se comenta la conducta seguida en ambos ojos(AU)

Capsule contraction syndrome is described as progressive, accelerated reduction in capsulorhexis and capsular bag diameter after extracapsular crystalline lens extraction. A case is presented of a female patient with a history of high myopia who underwent cataract surgery of both eyes without any intraoperative complication. One month after surgery the patient presents with bilateral capsule contraction syndrome. Comments are made on the clinical management of each eye(AU)

Assuntos

RESUMO

Case Description: A 16-year-old male patient presented with a 12-days sudden painless loss of vision in his left eye after diving in a lake. Best corrected visual acuity (BCVA) in the left eye was counting fingers. Anterior segment was unremarkable. Fundoscopy in the left eye revealed a pre-retinal hemorrhage in the macular region and swept-source ocular coherence tomography (SS-OCT) confirmed the location in the sub-inner limiting membrane (ILM) space. An Neodymium:YAG (Nd:YAG) laser membranotomy was performed the next day in order to drain the hemorrhage into the vitreous cavity. A couple of days after, the BCVA in the left eye improved to 20/ 25, at fundoscopy the blood being almost reabsorbed and the SS-OCT showing a resolution of the sub-ILM hemorrhage. Discussion: Due to Valsalva retinopathy, sub-ILM hemorrhage may lead to a sudden painless vision loss. Spontaneous resolution of the hemorrhage is possible but absorption may take a long time. During this period, intraretinal tissue migration and proliferation may lead to permanent structural damage. Posterior vitrectomy is a treatment option but the fact that it is an invasive procedure fuels the search for less invasive treatment methods and Nd:YAG laser membranotomy fits this place. Conclusion: Given the excellent results and low complication rates, Nd:YAG laser membranotomy is highly recommended to treat this condition as it offers a simple, relatively safe and a non-invasive treatment option for drainage of sub-ILM hemorrhages.

Assuntos

RESUMO

BACKGROUND: Vitreous floaters are a common and inconvenient phenomena. This study aims to examine the efficacy and safety in treating vitreous floaters using Nd:YAG laser vitreolysis. METHODS: In this prospective double-blinded randomized clinical trial 24 eyes of twenty-four patients were randomized into intervention with YAG laser vitreolysis and control groups. Primary outcomes were visual disturbance on a 10-point scale, qualitative changes in a 4-level scale, contrast sensitivity measured with the Pelli-Robson table and the National Eye Institute Visual Functioning Questionnaire 25 (NEI VFQ-25). Secondary results included objective change in vitreous opacities, best-corrected visual acuity (BCVA), variation in intraocular pressure (IOP) and other adverse events. RESULTS: Twenty-one patients (21 eyes; 5 male, 16 female) were enrolled in this study (mean age 62 ± 7.9 years), three were lost during follow-up. In the YAG laser group, the 10-point visual disturbance score improved a mean of 4.7 points (p < 0.001) compared to the control group that improved 2.1 (p = 0.09). The YAG laser group reported greater subjectively symptomatic improvement (77%) than controls (25%). NEI VFQ-25 revealed improved general vision (75.8 versus 59.2; p = 0.037) and in mental health at 6 months (84.3 versus 70.3; p = 0.048). There was no significant difference in contrast sensitivity (p = 0.848) and in IOP (p = 0.505). No differences in adverse events between groups were identified. CONCLUSION: Vitreolysis with Nd:YAG laser improves visual results in patients with symptomatic vitreous floaters, without adverse events considered clinically relevant. Other trials with a larger number of participants are required to corroborate these results.

Assuntos

RESUMO

OBJECTIVES: The present study examined a technique for reducing dentin permeability through the application of a calcium phosphate (CaP)-based desensitiser with a laser-assisted process and evaluated adhesive-dentin bond strength. Methods: Thirty dentin discs were divided into two groups according to whether the selected desensitiser (TeethMate; Kuraray Noritake) was used prior to dentin bonding. Each group was subdivided into three subgroups (n = 5): A- Adhesive (Single Bond Universal, 3M ESPE), AL- Adhesive + Laser (Nd:YAG 60 mJ) and LAL- Laser + Adhesive + Laser. Dentin permeability values (%) were recorded before and after desensitiser application. Resin composites were placed over the bonded specimens; the latter were aged prior to microtensile bond strength evaluation. Gelatinolytic activity within the hybrid layers was examined with in-situ zymography using confocal laser scanning microscopy. Data were analysed with ANOVA and Tukey test (α = 0.05). RESULTS: Significant differences in dentin permeability were identified for all groups (p = 0.00). Both laser treatment (p = 0.182) and desensitiser application (p = 0.687) did not significantly improve dentin bond strength. Ultrastructure of the resin-dentin interface identified presence of calcium phosphate within dentinal tubules. Laser treatment did not affect hybrid layer ultrastructure. Both treatment modalities (intratubular CaP occlusion and laser) had no influence on gelatinolytic activity within hybrid layers. CONCLUSION: Although intratubular CaP occlusion and laser treatment were effective in reducing dentin permeability, they did not affect bond strength, interfacial ultrastructure and gelatinolytic activity within hybrid layers. CLINICAL RELEVANCE: Treatment of etched dentin with Nd:YAG Laser at 60 mJ does not adversely affect collagen ultrastructure and gelatinolytic activity within the hybrid layer. The application of a calcium phosphate-based desensitiser to etch dentin does not affect dentin bond strength.

RESUMO

This in vitro study aimed to analyze the physical and chemical characteristics of the hypersensitive human dentin-like surface after application of a bioactive glass (BG) paste (BG/Ac) irradiated or not with high-power lasers. Dentin specimens were treated with 17% Ethylenediamine tetraacetic acid (EDTA) solution to mimic a hypersensitive dentin and then submitted to neodymium: yttrium-aluminum-garnet (Nd:YAG) laser or CO2 laser irradiation prior and after application of BG/Ac. Characterizations were performed by using X-ray diffraction, Fourier transformed infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The results suggested that application of BG/Ac by itself caused some obstructions of dentinal tubules. Nd:YAG laser irradiation reduced the opening of the dentinal tubules with no changes in the collagen structure. CO2 laser irradiation caused dentin melting and resolidification along with cracks and chemical changes in collagen fibers. However, when BG/Ac paste was irradiated with lasers, a sequence of surface reactions between glass and dentin interface led to the formation of an amorphous hydroxyapatite layer, similar to that of an inorganic component of the normal dentin. Moreover, BG/Ac was able to prevent the formation of cracks and degradation of collagen fibers caused by CO2 irradiation. Overall, this study supports that application of BG/Ac paste irradiated by high-power laser could represent an effective and long-lasting therapeutic approach for dentin hypersensitivity.

Assuntos

RESUMO

Objective: Evaluate the microtensile bond strength (µTBS) in different dentin thicknesses, under simulated pulpal pressure (SPP), submitted to an adhesive technique using laser irradiation. Material and methods: Forty sound human molars were sectioned and randomly divided into two groups (n=20): Group 1 ­ 1 mm of dentin thickness; Group 2 ­ 2 mm of dentin thickness. Each group was divided into two subgroups (n=10): Subgroup A ­ Absence of SPP; Subgroup P ­ Presence of SPP (15 cm H2 O). The samples were sequentially treated with: 37% phosphoric acid, adhesive system (Adper Single Bond 2), Nd:YAG laser irradiation (60 s, 1064 nm, 10 Hz) using 60 and 100 mJ/pulse energy parameters and photopolymerization (10 s). A composite resin block (Filtek Z350) was built up onto the irradiated area. After 30 days stored in water, the samples were sectioned and submitted to microtensile test (10 kgf load cell, 0.5mm/min). Data were analyzed by twoway ANOVA and Tukey tests. Results: Two-way ANOVA revealed no significant differences for SPP on bond strength. The laser energy parameters indicated that 100 mJ showed greater µTBS means compared to the group irradiated with 60 mJ. The presence of SPP reduced the mean µTBS values. Conclusions: Simulated pulpal pressure did not affect the µTBS using 60 mJ of laser energy parameter. At 100 mJ, the presence of SPP negatively influenced the bond strength, regardless of dentin thickness (AU)

Objetivo: O objetivo deste estudo foi avaliar a resistência adesiva (RA) em diferentes espessuras de dentina, associada à pressão pulpar simulada (PPS), quando submetidos à técnica adesiva por irradiação laser. Material e Métodos: Quarenta molares humanos hígidos foram seccionados e divididos aleatoriamente em dois grupos (n=20): Grupo 1 ­ 1 mm de espessura de dentina; Grupo 2 ­ 2 mm de espessura de dentina. As amostras foram divididas em 2 subgrupos (n=10): Subgrupo A ­ ausência de PPS; Subgrupo P ­ presença de PPS (15 cm de H2 O). As amostras foram tratadas seqüencialmente com: ácido fosfórico 37%, sistema adesivo (Adper Single Bond 2), irradiação com Nd:YAG laser (60 s, 1064 nm, 10 Hz) nos parâmetros de energia de 60 e 100 mJ/pulso e fotopolimerização (10 s). Um bloco de resina composta (Filtek Z350, 3M ESPE) foi confeccionado sobre a área irradiada. Após 30 dias armazenados em água, os espécimes foram seccionados e submetidos ao teste de microtração (carga de 10 kgf, 0.5mm/min). Os dados foram analisados pelos testes ANOVA sob 2 fatores e Tukey (p<0.05). Resultados: ANOVA mostrou que não houve diferenças significativas para PPS na RA. Para os parâmetros de energia do laser, 100 mJ apresentou maiores médias de RA quando comparado ao grupo irradiado à 60 mJ. A presença da PPS reduziu as médias de RA. Conclusão: Pressão pulpar simulada não afetou os valores de resistência adesiva para o grupo irradiado com 60 mJ. Para 100 mJ, a presença da pressão pulpar influenciou negativamente na resistência adesiva, independente das espessuras de dentina.(AU)

Assuntos

RESUMO

Massive hyphaema presentation after a laser iridotomy is very rare. We report a 63-year-old man with ischaemic heart disease on dual antiplatelet therapy (aspirin plus ticagrelor) who was diagnosed as a primary angle-closure suspect and was to undergo a neodymium-doped yttrium aluminium garnet laser iridotomy at Centro Oftalmológico Virgilio Galvis, Floridablanca, Colombia in 2016. While performing the iridotomy in the left eye, active bleeding occurred that finally filled approximately 75% of the anterior chamber. Intraocular pressure (IOP) increased to 62 mmHg. Mannitol and a topical dorzolamide/timolol were used to control the increase in IOP. The hyphaema slowly resolved over the following week without sequelae. This case revealed that massive hyphaema can complicate laser iridotomy in patients on dual antiplatelet therapy, although this is rare. Therefore, if patients are taking aspirin and ticagrelor, it would be advisable to stop the second medication if possible. In addition, sequential application of photocoagulation and photodisruption lasers might diminish the risk of significant bleeding.

Assuntos

RESUMO

Objective: The aim of this article was to describe and discuss a clinical case in which the Nd:YAG laser and a desensitizing agent were associated in a protocol for dentin hypersensitivity (DH) in teeth with molar-incisor hypomineralization (MIH). Background data: DH is a common condition among the population, being one of the main reasons for patients to seek for a dental treatment. MIH can be considered a condition that induces DH. Methods: The patient was referred for evaluation, complaining of hypersensitivity during eating or drinking cold foods. Clinical evaluation revealed the presence of MIH on the first lower molars. Aiming to treat DH, two strategies for dentin desensitization were associated: the use of a high-power laser (Nd:YAG laser, 1.064 nm; Lares Research), with a 300 µm quartz optical fiber, 1 W of power, 100 mJ of energy, 10 Hz of repetition rate, and 85 J/cm2 of energy density, followed by the application of two layers of a desensitizing agent (Gluma Desensitizer). Results: DH was evaluated immediately, after 1 week and after 1 month of the treatment. Clinical outcomes were satisfactory, confirming the efficacy and considerable durability of the protocol used for the reduction of DH originated from MIH. Conclusions: The association of Nd:YAG laser and a desensitizing agent for controlling DH was effective, showing to be an interesting protocol.

Assuntos

RESUMO

AIM: This double-blind, placebo-controlled, randomized clinical trial evaluated the effectiveness of Nd:YAG laser and a calcium sodium phosphosilicate-containing paste (NovaMin®) in the treatment of cervical dentin hypersensitivity (CDH). MATERIALS AND METHODS: Seventy patients were randomly allocated into the following experimental groups: control-placebo, calcium sodium phosphosilicate paste (NovaMin®), and Nd:YAG laser (1 W, 10 Hz, 85 J/cm2). Pain was evaluated by means of a visual analog pain scale (VAS) after evaporative stimulation with a jet of air and tactile stimulation with an exploratory probe, before treatment (baseline) and after 5 min, 1week, and 4 weeks. When patients presented more than one tooth with CDH, the mean of the values obtained was calculated. Irradiation with Nd:YAG laser was performed twice in the mesial-distal and twice in the occlusal-gingival direction. The NovaMin®-containing paste was applied with a rubber cup at low speed for 60 s. Patients of the placebo group received simulations of the two treatments. As the data presented normal distribution, the two-way ANOVA repeated measures test was used. RESULTS: In all the experimental times, reduction in pain was demonstrated in comparison with baseline for all treatments (p < 0.05); however, there was no difference among the experimental groups in any of the time intervals evaluated (p > 0.05). CONCLUSION: All treatments were equally effective in reducing the pain of CDH. CLINICAL RELEVANCE: Nd:YAG laser irradiation and the calcium sodium phosphosilicate paste could reduce the symptoms of CDH; thus, they stand out as viable alternatives for the treatment of this condition.

Assuntos

RESUMO

RESUMEN El objetivo del presente estudio fue evaluar los efectos de la aplicación de un antioxidante sobre las fuerzas de unión (SBS) de brackets de ortodoncia posterior al blanqueamiento con peróxido de hidrógeno (HP). Metodología: Cincuenta premolares recién extraídos se dividieron aleatoriamente en tres grupos. El Grupo 1 se trató con 40% de HP (n=20), el grupo 2 con 40% de HP y se activó con láser de Nd: YAG (n=20) y un grupo de control (Grupo 3) no recibió tratamiento (n=10). Después del blanqueamiento, los Grupos 1 y 2 se dividieron en dos subgrupos (Grupo 1a, Grupo 1b, Grupo 2a y Grupo 2b). Las muestras en los subgrupos 1a y 2a (n=10) no recibieron ninguna aplicación del antioxidante. Se aplicó una solución de ascorbato de sodio al 10% a las muestras en los Grupos 1b y 2b (n=10). Luego, los brackets se adherieron a las superficies de esmalte de todos los grupos experimentales. Las muestras se sometieron a pruebas de SBS y los datos analizados estadisticamente. Resultados: La fuerza de unión de los grupos 1 y 2 fue significativamente más baja que el grupo de control (p <0.001); sin embargo, no se observaron diferencias estadísticamente significativas en SBS entre los grupos 1 y 2 (p>0.001). Las muestras tratadas con antioxidantes de los grupos 1b y 2b fueron significativamente mayores que las de los grupos 1a y 2a (p <0,001). Conclusion: La aplicación de 40% HP tuvo un efecto negativo en la resistencia de unión de los brackets. El uso de antioxidante durante 15 minutos mejoró significativamente la SBS.

ABSTRACT Purpose: The purpose of this study was to evaluate the effects of the application of antioxidant on the shear bond strengths (SBS) of orthodontic brackets bonded to human enamel after extra-coronal bleaching with hydrogen peroxide (HP). Materials and methods: Fifty freshly extracted premolars were randomly divided into three groups. One group (Group 1) was bleached with 40% HP (n=20), another group (Group 2) was bleached with 40% HP and activated with an Nd: YAG laser (n=20), and a control group (Group 3) received no treatment (n=10). After the bleaching procedure, Groups 1 and 2 were further divided into two subgroups (Group 1a, Group 1b, Group 2a, and Group 2b). Specimens in Groups 1a and 2a (n=10) received no antioxidant application. A 10% sodium ascorbate solution was applied to specimens in Groups 1b and 2b (n=10). The brackets were then bonded with light-cure adhesive paste to the enamel surfaces of all experimental groups. Specimens were subjected to SBS tests for debonding. Results: The SBS of brackets bonded in Groups 1 and 2 were significantly lower than those of brackets bonded to the control group (p<0.001); however, no statistically significant differences in SBS were noted in Groups 1 and 2 (p>0.001). The antioxidant-treated SBS of brackets in Groups 1b and 2b were significantly higher than those of Groups 1a and 2a (p<0.001). Conclusions: The application of 40% HP had a negative effect on the bond strength. The use of antioxidant for 15 min resulted in the reversal of failed bond strength.

Assuntos

RESUMO

BACKGROUND: Dermal fillers are widely used for facial and body contouring. Polymethylmethacrylate (PMMA) is a permanent biphasic filler for soft tissue augmentation. In case of unwanted side effects, drug therapy and surgical excision have been commonly used with mixed results. AIM: We report on a series of patients with adverse events to PMMA and an innovative minor invasive procedure to reduce disfigurement by nodules and lumps. METHODS: We employed a subdermal, intralesional 1,064 nm neodymium-doped yttrium aluminium garnet (Nd: YAG) laser in combination with suction using a blunt liposuction cannula of 2.0-2.5 mm of diameter. RESULTS: For 12 years, a total of 81 consecutive subjects (79 females and 2 males) were treated. The average age of the patients was 43.7 years (range 26 to 76 years). Granulomas and lumps could be removed in a minor invasive procedure with tumescent anaesthesia. In a minority of cases, the procedure had to be repeated. The results were impressive and not adverse events related to intralesional laser therapy were observed, 86.4% of patients were satisfied. CONCLUSION: The procedure should be used before or in combination with classical surgery to remove PMMA in case of adverse tissue reactions to PMMA.

RESUMO

Onychomycosis is the most frequent nail disease, with an estimated prevalence of 2-8%. Current treatment strategies include the use of oral and topical antifungals, despite low cure rates following these treatments. The objectives of this study were to assess the therapeutic response of patients with onychomycosis to 1,064-nm Nd:YAG laser treatment, the clinical evaluation method available for this therapy, and the possible side effects of this treatment. Twenty patients with onychomycosis underwent laser therapy. A total of 34 nails with onychomycosis were assessed according to the Onychomycosis Severity Index (OSI). This index generates scores that classify onychomycosis as mild, moderate, or severe. The OSI was determined before treatment and after a mean follow-up period of 8 months. The comparison between the initial and the final OSI for all 34 nails treated with laser therapy showed a significant difference; however, a low association was shown between these variables. A general reduction in the area of involvement and in the OSI numerical scores was observed. These data show a trend toward improvement in onychomycosis treated with 1,064-nm Nd:YAG laser. The OSI allowed an adequate clinical assessment of the response to laser therapy. Laser treatment did not cause marked discomfort in most patients, indicating that laser is a well-tolerated procedure.

RESUMO

BACKGROUND: Facial reticular blue veins are of esthetic concern. Most often these veins develop on the lower lids. The safest and most effective way of treatment is by vascular lasers. CASE REPORT: We report on a successful reticular vein treatment using a long-pulsed 1064 nm Nd: YAG laser. We present a follow-up of 8 years with constant esthetic improvement without unwanted adverse events. CONCLUSION: There was no relapse demonstrating the efficacy of Nd: YAG laser.

RESUMO

Conventional systemic and topical treatments have proven ineffective for the treatment of onychomycosis caused by Neoscytalidium dimidiatum. Our aim was to evaluate the effectiveness and safety of laser monotherapy for the treatment of onychomycosis caused by this pathogen. Patients with clinical onychomycosis of the toenails and positive results both on direct mycological examination and N. dimidiatum culture underwent four 1064 nm Nd:YAG laser sessions with 6-week intervals between sessions. Participants were monitored by clinical examination supported by dermoscopy, measurement of diseased nail and the onychomycosis severity index (OSI), and by mycological examination for 12 months after completion of treatment. Treatment outcome was based on clinical and laboratory criteria and was divided in complete or partial cure, clinical improvement, treatment failure and relapse. No patient had complete or partial cure at any time during the study. Clinical improvement was observed in 40.6% of the patients at the end of the laser sessions; however, it did not persist during the follow-up. Treatment failure was observed in 64.7% of the patients at the end of 12 month follow-up period. Direct microscopy and culture results remained positive in most patients. Adverse events, in addition to treatment-related pain, were observed and considered severe in one case. The 1064 nm Nd:YAG laser was not able to cure onychomycosis caused by N. dimidiatum but temporarily improved the clinical appearance of the nail; however, adverse events may occur.

Assuntos