Sample records for ysgg laser estudo

  1. Biocompatibility of Er:YSGG laser radiated root surfaces

    Benthin, Hartmut; Ertl, Thomas P.; Schmidt, Dirk; Purucker, Peter; Bernimoulin, J.-P.; Mueller, Gerhard J.


    Pulsed Er:YAG and Er:YSGG lasers are well known to be effective instruments for the ablation of dental hard tissues. Developments in the last years made it possible to transmit the laser radiation at these wavelengths with flexible fibers. Therefore the application in the periodontal pocket may be possible. The aim of this study was to evaluate the in-vitro conditions to generate a bioacceptable root surface. Twenty extracted human teeth, stored in an antibiotic solution, were conventionally scaled, root planed and axially separated into two halves. Two main groups were determined. With the first group laser radiation was carried out without and in the second group with spray cooling. The laser beam was scanned about root surface areas. Laser parameters were varied in a selected range. The biocompatibility was measured with the attachment of human gingival fibroblasts and directly compared to conventionally treated areas of the root surfaces. The fibroblasts were qualified and counted in SEM investigations. On conventionally treated areas gingival fibroblasts show the typical uniform cover. In dependance on the root roughness after laser treatment the fibroblasts loose the typical parallel alignment to the root surface. With spray cooling a better in-vitro attachment could be obtained. Without spray cooling the higher increase in temperature conducted to less bioacceptance by the human gingival fibroblasts to the root surface. These results show the possibility of producing bioacceptable root surfaces with pulsed laser radiation in the range of very high water absorption near 3 micrometer.

  2. In vitro study of demineralization resistance and fluoride retention in dental enamel irradiated with Er,Cr: YSGG laser; Estudo in vitro da resistencia a desmineralizacao e da retencao de fluor em esmalte dental irradiado com laser de Er, Cr: YSGG

    Ana, Patricia Aparecida da. E-mail:


    This study aimed to establish irradiation conditions of Er,Cr:YSGG laser ({lambda} of 2.79 {mu}m) which could propitiate changes on human dental enamel and increase its resistance to demineralization, when associated or not with topical application of acidulated phosphate fluoride (APF). Fluences of 2,8 J/cm{sup 2}, 5,6 J/cm{sup 2} e 8,5 J/cm{sup 2} were selected; they were associated or not with previous application of a photo absorber (coal paste) and then APF was applied or not after laser irradiation. In a first step, the morphological findings, the surface temperatures, and the pupal temperatures were evaluated during laser irradiation. After that, the treated samples were submitted to a a ten-day pH-cycling model. After producing the incipient white-spots lesions, the following aspects were evaluated: the mineral loss, the loosely bound fluoride and the firmly bound fluoride. All the demineralizing and remineralizing pH-cycling solutions were evaluated with respect to their calcium (Ca), inorganic phosphorous (Pi) and fluoride (F{sup -}) concentrations. The data had their normality and homogeneity distribution statistically evaluated, and it was chosen an appropriated statistical test for each performed analysis according to the obtained results, considering 5% significant level. The fluences selected for this study created ablated surfaces; the fluences of 5.6 J/cm{sup 2} and 8.5 J/cm{sup 2} promoted increments in surface temperature above 110 deg C. The intrapupal temperature changes revealed that laser irradiation did not increase the pulpal temperatures above the critical threshold for induction of pulpitis. The coal paste did not promote any changes on surface morphology or in the intrapulpal temperature changes; however, this paste increased the surface temperatures during laser irradiation. Only laser irradiation at 8.5 J/cm{sup 2} was able to decrease the mineral loss when compared to the no-treatment group; although the association of coal paste

  3. Histopathological evaluation of pulpotomy with Er,Cr:YSGG laser vs formocresol.

    Toomarian, Lida; Fekrazad, Reza; Sharifi, Davood; Baghaei, Mojdeh; Rahimi, Hessam; Eslami, Behnam


    The purpose of this study was to histologically investigate whether pulpotomy with Er,Cr:YSGG laser is an acceptable alternative for formocresol. Pulpotomy of 48 dog's primary canine teeth was performed with formocresol or Er,Cr:YSGG laser. Histological evaluations on hematoxylin and eosin-stained pulp tissues were made by an optical microscope 7 or 60 days later. Statistical analysis was performed with Fisher's exact test, Mann-Whitney U test, and Student's t test. Seven days after pulpotomy, samples treated with laser had significantly favorable histological features in the following measures: continuity of odontoblastic layer (Pformocresol in pulpotomy of deciduous teeth.

  4. [Effects of Er, Cr: YSGG laser on the root surface of periodontitis and healthy teeth].

    Qu, Chun-na; Kang, Jun; Luan, Qing-xian


    To evaluate the effects of Er, Cr: YSGG laser on the root surface of periodontally involved teeth and healthy teeth, concerning the microstructure and the roughness. Eight freshly extracted teeth due to severe periodontitis and eight freshly extracted teeth due to orthodontic reasons or being third molar were chosen in this study. The root surface of each tooth was divided into four areas, and received four treatment no treatment (control group); root planing with Gracey scaler for 30 seconds; irradiation by the lower power Er, Cr: YSGG laser; irradiation by the higher power Er, Cr: YSGG laser. Four periodontally involved teeth and four healthy teeth were used for the evaluation of microstructure using scanning electron microscope (SEM). The other four periodontitis teeth and four healthy teeth were used for the evaluation of roughness (Ra value) using 3D profiler. Smear layer was found on the teeth scaled by Gracey scaler, while the teeth irradiated by Er, Cr: YSGG laser demonstrated a melting surface with less smear layer. In the periodontitis teeth irradiated by the higher power, opening dentinal tubules could be observed. For the periodontally involved teeth, the Ra values of groups 1 to 4 were (237.4 ± 20.0) nm, (135.7 ± 11.9) nm (P=0.01), (463.6 ± 49.3) nm (Plaser can affect the microstructure of the cementum of the periodontitis teeth and healthy teeth. Irradiation by the Er, Cr: YSGG laser resulted in a melting surface with less smear layer and increased the roughness in the surface of root.

  5. Effect of instrumentation using curettes, piezoelectric ultrasonic scaler and er,cr:Ysgg laser on the morphology and adhesion of blood components on root surfaces - A SEM study

    Tsurumaki, Jackeline do Nascimento [UNESP; Souto,Bráulio Henrique Marques; de Oliveira, Guilherme José Pimentel Lopes; Sampaio, José Eduardo Cezar [UNESP; Marcantonio Júnior, Elcio [UNESP; Marcantonio, Rosemary Adriana Chierici [UNESP


    This study used scanning electron microscopy (SEM) to evaluate the morphology and adhesion of blood components on root surfaces instrumented by curettes, piezoelectric ultrasonic scaler and Er,Cr:YSGG laser. One hundred samples from 25 teeth were divided into 5 groups: 1) Curettes; 2) Piezoelectric ultrasonic scaler; 3) Curettes plus piezoelectric ultrasonic scaler; 4) Er,Cr:YSGG laser; 5) Curettes plus Er,Cr:YSGG laser. Ten samples from each group were used for analysis of root morphology an...

  6. Assessment of root caries removal by Er,Cr:YSGG laser

    Geraldo-Martins, Vinícius R.; Marques, Márcia M.


    The present study aimed to compare root caries removal by air turbine and Er,Cr:YSGG laser, and examine morphological changes after these caries removal techniques under scanning electron microscopy (SEM). Seventy two extracted human carious-free third molars were used in this study. After the in vitro root caries induction using S. mutans, the carious lesions were removed by the conventional technique, using burs (control), and by the Er,Cr:YSGG laser, using 13 different parameters, between 1 and 4,0 W. During caries removal, preparation time was recorded for all groups. The results appointed out that the conventional method was the fastest one. When only laser treatment was evaluated, the higher parameters seemed to remove caries faster then the lower ones. SEM revealed that the surfaces treated by air turbine were smooth, but with debris. The laser groups demonstrated smooth undulations, with little or absence of smear layer, and no signs of carbonization. These results suggest that caries removal by Er,Cr:YSGG laser was effective. Therefore, this equipment requires training on cavity preparation, in order to avoid damages in dental hard tissues.

  7. Influence of Er,Cr:YSGG laser treatment on microtensile bond strength of adhesives to enamel.

    Cardoso, Marcio Vivan; De Munck, Jan; Coutinho, Eduardo; Ermis, R Banu; Van Landuyt, Kirsten; de Carvalho, Rubens Corte Real; Van Meerbeek, Bart


    The current trend towards minimum-intervention dentistry has introduced laser technology as an alternative technique for cavity preparation. This study assessed the null hypothesis that enamel prepared either by Er,Cr:YSGG laser or conventional diamond bur is equally receptive to adhesive procedures. The buccal and lingual surfaces of 35 sound human molars were prepared with Er,Cr:YSGG laser or a medium-grit diamond bur. One etch&rinse (OptiBond FL) and three self-etch adhesives (Adper Prompt L-Pop, Clearfil SE Bond and Clearfil S3 Bond) were applied on laser-irradiated and bur-cut enamel, followed by the application of a 5-6 mm build-up of Z100. The micro-tensile bond strength (microTBS) was determined after 24 hours of storage in water at 37 degrees C. Prepared enamel surfaces and failure patterns were evaluated using a stereomicroscope and a field-emission-gun scanning electron microscope (Feg-SEM). The pTBS to laser-irradiated enamel was significantly lower than to bur-cut enamel (pOptiBond FL. SEM analysis revealed significant morphological alterations of the laser-irradiated enamel surface, such as areas of melted and recrystalized hydroxyapatite and deep extensive micro-cracks. In conclusion, the bonding effectiveness of adhesives to laser-irradiated enamel depends not only on the structural substrate alterations induced by the laser, but also on the characteristics of the adhesive employed.

  8. Er,CR:YSGG lasers induce fewer dysplastic-like epithelial artefacts than CO2 lasers: an in vivo experimental study on oral mucosa.

    González-Mosquera, A; Seoane, J; García-Caballero, L; López-Jornet, P; García-Caballero, T; Varela-Centelles, P


    Our aim was to assess wounds made by lasers (CO(2) and Er,Cr:YSGG) for their epithelial architectural changes and width of damage. We allocated 60 Sprague-Dawley(®) rats into groups: glossectomy by CO(2) laser at 3 different wattages (n=10 in each); glossectomy by Er,Cr:YSGG laser at two different emissions (n=10 in each), and a control group (n=10). Histological examination assessed both prevalence and site of thermal artefacts for each group. Both lasers (CO(2) and Er,Cr:YSGG) caused the same type of cytological artefacts. The 3W Er,Cr:YSGG laser produced the fewest cytological artefacts/specimen, and was significantly different from the other experimental groups: 3W CO(2) laser (95% CI=0.8 to 1.0); the 6W CO(2) laser (95% CI=0.1 to 2.0) and the 10W CO(2) laser (95% CI=1.1 to 3.0). CO(2) lasers (3-10W) generate epithelial damage that can simulate dysplastic changes with cytological atypia that affects mainly the basal and suprabasal layers. Irradiation with Er,CR:YSGG laser (2-4W) produces significantly fewer cellular artefacts and less epithelial damage, which may be potentially useful for biopsy of oral mucosa.

  9. Calcium solubility of dental enamel following Er, Cr:YSGG laser irradiation

    Apel, Christian; Graeber, Hans-Georg; Gutknecht, Norbert


    Ever since the laser was introduced in dental medicine, there has been a constant discussion about its use in caries prevention. Various studies have already illustrated the possible uses of CO2 and argon lasers in this field of dentistry. The aim of the present study was to examine the Er,Cr:YSGG laser with regard to potential in reducing the acid solubility of dental enamel. Thirty freshly extracted bovine incisor teeth were prepared for this purpose. The crowns of the teeth were covered with hard wax, leaving a standardized test area free. The test specimens were then divided into three groups. The test area was uniformly irradiated with 2.7 J/cm2 in the first test group and 6.5 J/cm2 in the second test group. The third test group was left untreated (control group). Demineralization of the teeth was performed over a period of 24 hours in acetate buffer solution (0.1 mol/l) with a pH value of 4.5 and a temperature of 37 degrees Celsius. The calcium content of the solution was subsequently determined by flame photometry. The results confirm a significantly lower calcium content in the test group exposed to radiation of 6.5 J/cm2 (p less than 0.025). Dental enamel seems to have increased acid resistance following irradiation with the Er,Cr:YSGG laser.

  10. Effect of an Er,Cr:YSGG laser on water perfusion in human dentine.

    Adu-Arko, Ampong Y; Sidhu, Sharanbir K; McCabe, John F; Pashley, David H


    Changes in fluid perfusion through tubules may affect the sensitivity of exposed and restored dentine. The rate of perfusion is dependent on the structure and composition of dentine, particularly at the surface. This work analyzed the effect of treatment with an Erbium, Chromium-doped: Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser on dentine perfusion. Extracted molars were sectioned above the mid-coronal portion, and below the cemento-enamel junction, to create crown segments. The pulp was extirpated and the dentine treated with the Er,Cr:YSGG laser, a diamond bur or sandpaper. Each specimen was mounted, with the pulp chamber oriented upwards, on a petri-dish cover in order to permit a tube filled with water to be connected to the pulp. Movement of the water meniscus over 24 h provided a measurement of the volume of water that filtered across the dentine. The dishes contained water to provide a moist environment in the relevant specimens, or were left dry to provide dry conditions. Specimens were perfused for 24 h with water pressures ranging from 20 to 60 cm. The results (in μl mm(-2) d(-1) ) showed a significant difference in the perfusion rate between treatments. The difference between perfusion in wet and dry conditions was highly significant. Laser and bur treatment of dentine significantly affected perfusion, which was higher in the former than in the latter. Therefore, laser-treated dentine may be more sensitive than bur-cut dentine.

  11. Modification of tooth and enamel characteristics following the Er,Cr:YSGG laser treatment

    Suhaimi, Fatanah M.; Aziz, N. Afifah; Jaafar, M. S.; Azizan, Nur Syazana; Zali, Nurulakma; Razak, N. A. Abd


    Lasers have been widely used in the dental field to treat a number of applications in dentistry. The main objective of this study is to analyse the modification of tooth composition following the Er,Cr:YSGG laser procedure. In this study, human premolar teeth were collected and prepared. The samples were sectioned and molded. 3M Unitek Transbond™ Plus Self Etching Primer adhesive materials were applied to the tooth surface. Er,Cr:YSGG laser with a wavelength of 2790 nm was used in this study to remove the adhesive materials on the enamel surface. The irradiation process was done with four different output powers that are 0.25, 0.5, 0.75, and 1.0 W. The change of tooth characteristics was analysed by observing the morphology of the enamel surface and the elemental composition usinga Field Emission Scanning Electron Microscope (FESEM) and Electron Dispersive X-ray Spectrometer (EDX). Calcium (Ca), phosphorus (P), sodium (Na), oxygen (O), and carbon (C) were the elementsidentified by EDX in the samples. Additionally, oxygen was the most abundant element found in the sample. The level of oxygen composition decreased after laser irradiation while the carbon element increased. Another element, calcium was found to be decreasing due to the process of applying adhesive materials on the enamel surface.

  12. Comparing efficiency and root surface morphology after scaling with Er:YAG and Er,Cr:YSGG lasers.

    Etemadi, Ardavan; Sadeghi, Mostafa; Abbas, Fatemeh Mashhadi; Razavi, Fahime; Aoki, Akira; Azad, Reza Fekr; Chiniforush, Nasim


    The purpose of this study was to investigate the root morphology of teeth and efficiency of scaling after using Er:YAG and Er,Cr:YSGG lasers. Thirty-two periodontally hopeless teeth were extracted. The border of an appropriate calculus was marked using a diamond bur on each tooth, and the calculus was divided into two almost equal parts. An Er,Cr:YSGG laser with pulse energy of 50 mJ, power of 1 W, and energy density of 17.7 J/cm2 and an Er:YAG laser with pulse energy of 200 mJ, power of 2.4 W, and energy density of 21 J/cm2 were used to remove the calculus. The time for scaling was recorded for each group, and using stereomicroscopic analysis, the calculus remnant, carbonization, and number of craters were investigated. The mean time required for calculus removal in the Er,Cr:YSGG and Er:YAG laser groups was 15.22 ± 6.18 seconds and 7.12 ± 4.11 seconds, respectively. The efficiency of calculus removal in the Er:YAG laser group was significantly higher than in the Er,Cr:YSGG laser group. Under stereomicroscope examination, no carbonization or remaining calculus was found in samples from either group, but all samples had craters. The number of craters in the Er,Cr:YSGG laser group was significantly higher than in the Er:YAG laser group. According to the parameters used and limitations of this study, there was no significant difference in efficiency per power for calculus removal between the two groups.

  13. Evaluation of ultrasonic and ErCr:YSGG laser retrograde cavity preparation.

    Batista de Faria-Junior, Norberto; Tanomaru-Filho, Mário; Guerreiro-Tanomaru, Juliane Maria; de Toledo Leonardo, Renato; Camargo Villela Berbert, Fábio Luiz


    Root end cavity preparation techniques aim to create a clean and properly shaped cavity in a short time. Although the use of ultrasonics has been widely recommended, a laser can also be used. This study evaluated the time required and quality of retrograde cavity preparations using ultrasonics or ErCr:YSGG laser. Thirty single-rooted teeth were instrumented, root filled, submitted to apicectomies, and grouped. Root end cavities were prepared by using the following: group 1 (G1): CVD (6.1107-6) ultrasonic retrotips (CVD-Vale, São José dos Campos, Brazil); group 2 (G2): EMS (DT-060/Berutti) ultrasonic retrotips (EMS, LeSentier, Switzerland); and group 3 (G3): ErCr:YSGG (G6/Waterlase; Biolase Technology, San Clemente, CA) laser tips. The time taken to complete the preparation was recorded. Epoxy resin replicas of the root apices were examined under a scanning electron microscope. The parameters for evaluation were the presence of fractures, and the quality of the preparations. The Waterlase showed the highest mean time for preparation of the root end cavities (p 0.05). Fractures in the cavosurface angle occurred only in G2. G1 and G2 showed better scores for quality of preparation than G3 (p < 0.05). These results suggest that root end cavities should be prepared by ultrasonic tips.

  14. Effect of different power parameters of Er,Cr:YSGG laser on human dentine.

    Ekworapoj, Piyanart; Sidhu, Sharanbir K; McCabe, John F


    The aim of this work was to determine the optimal power setting of an Er,Cr:YSGG laser for cutting human dentine to produce a surface that remains suitable as a foundation on which to build and bond a dental restoration. The cutting efficiency and resulting microhardness of the dentine were evaluated for various laser power settings, and representative samples were examined by SEM. The microhardness of the dentine was significantly reduced by 30-50% (p power setting used. The mean ablation efficiency increased in proportion to the power setting of the laser. Although the laser power setting did not affect the extent of reduction in microhardness, it did affect the microstructure of human dentine.

  15. Er,Cr:YSGG laser labial frenectomy: a clinical retrospective evaluation of 156 consecutive cases.

    Olivi, Giovanni; Chaumanet, Gilles; Genovese, Maria Daniela; Beneduce, Carla; Andreana, Sebastiano


    The labial frenum may impede oral hygiene and result in diastema between anterior teeth and traction of the attached gingiva. Surgical removal of the frenum during puberty has been recommended for these patients. This article clinically evaluates the efficacy of an Er,Cr:YSGG laser in removing the labial frenum in an adolescent and pre-pubescent population. Using an Er,Cr:YSGG laser at a power setting of 1.5 W or less and 20 to 30 pulses per second, a total of 156 frenectomies were performed on 143 children. Patients returned for recall visits at 3, 7, 21, and 30 days and at one, two, and three years. Surgical areas were checked for adverse events, recurrency of frenum, and functional complications. Patient acceptance was also evaluated by using the Wong-Baker FACES pain rating scale. Thirteen recurrences were reported in the adolescent population at 21 or 30 days, all of which required re-intervention; however, only two cases displayed recurrence of the frenum. None of the three pre-pubescent cases required additional intervention, maintaining acceptable clinical results after three years. Patient acceptance was very high, and no postoperative adverse events were reported.

  16. Er, Cr:YSGG laser for the treatment of ankyloglossia.

    Lamba, Arundeep K; Aggarwal, Kamal; Faraz, Farrukh; Tandon, Shruti; Chawla, Kirti


    Ankyloglossia or tongue-tie is the result of a short and tight lingual frenum causing difficulty in speech, feeding problems in infants due to the limitation of tongue movement. This report presents a case of a 22-year-old female with tongue-tie who complained of difficulty in speech following which she underwent frenectomy procedure with erbium, chromium: yattrium-scandium-gallium-garnet laser without any complications. She was referred to the speech therapist after the procedure.

  17. Effect of instrumentation using curettes, piezoelectric ultrasonic scaler and Er,Cr:YSGG laser on the morphology and adhesion of blood components on root surfaces: a SEM study.

    Tsurumaki, Jackeline do Nascimento; Souto, Bráulio Henrique Marques; Oliveira, Guilherme José Pimentel Lopes de; Sampaio, José Eduardo Cézar; Marcantonio Júnior, Elcio; Marcantonio, Rosemary Adriana Chiérici


    This study used scanning electron microscopy (SEM) to evaluate the morphology and adhesion of blood components on root surfaces instrumented by curettes, piezoelectric ultrasonic scaler and Er,Cr:YSGG laser. One hundred samples from 25 teeth were divided into 5 groups: 1) Curettes; 2) Piezoelectric ultrasonic scaler; 3) Curettes plus piezoelectric ultrasonic scaler; 4) Er,Cr:YSGG laser; 5) Curettes plus Er,Cr:YSGG laser. Ten samples from each group were used for analysis of root morphology and the other 10 were used for analysis of adhesion of blood components on root surface. The results were analyzed statistically by the Kruskall-Wallis and Mann-Whitney tests with a significance level of 5%. The group treated with curettes showed smoother surfaces when compared to the groups were instrumented with piezoelectric ultrasonic scaler and the Er,Cr:YSGG laser. The surfaces instrumented with piezoelectric ultrasonic scaler and Er,Cr:YSGG laser, alone or in combination with hand scaling and root planing, did not differ significantly (p>0.05) among themselves. No statistically significant differences (p>0.05) among groups were found as to the adhesion of blood components on root surface. Ultrasonic instrumentation and Er,Cr:YSGG irradiation produced rougher root surfaces than the use of curettes, but there were no differences among treatments with respect to the adhesion of blood components.

  18. Investigations of radicular dentin permeability and ultrastructural changes after irradiation with Er,Cr:YSGG laser and dual wavelength (2780 and 940 nm) laser.

    Al-Karadaghi, Tamara Sardar; Franzen, Rene; Jawad, Hussein A; Gutknecht, Norbert


    The aim of this study was to assess the effectiveness of dual wavelength (2780 nm Er,Cr:YSGG, 940 nm diode) laser in elimination of smear layer comparing it with Er,Cr:YSGG laser in terms of radicular dentin permeability and ultrastructural changes of root canal walls. Fifty-one sound single-rooted extracted teeth were instrumented up to size F4 and divided into three groups: group Co, non-irradiated samples; group A, irradiated with Er,Cr:YSGG laser; group B, irradiated with the dual wavelength laser. Afterward, the roots were made externally impermeable, filled with 2% methylene blue dye, divided horizontally into three segments reflecting the cervical, middle, and apical thirds then examined under microscope. Using analytical software, the root section area and dye penetration area were measured, and then, the percentage of net dye penetration area was calculated. Additionally, scanning electron microscope investigations were accomplished. Analysis of variance (ANOVA) showed significant differences between all groups over the three root thirds. Dye permeation in dual wavelength laser group was significantly higher over the whole root length: cervical, middle, and apical compared to Er,Cr:YSGG laser group and non-irradiated samples (p laser root canal irradiation produced uneven removal of smear layer, in efficient cleanliness especially in the apical third. There was no sign of melting and carbonization. Within the studied parameters, root canal irradiation with dual wavelength laser increased dentin permeability.

  19. Fluoride glass fiber for reliable Er:YAG and Er,Cr:YSGG laser power delivery

    Séguin, François; Saad, Mohammed; Orsini, Patrick; Baierl, Dieter


    Compared to other transparent infrared fiber materials, ZBLAN fluoride glasses promise to be best suited for laser power delivery in the 3μm wavelength region due to their high transmission and excellent mechanical flexibility. These claims were demonstrated in a series of power handling tests of both straight and coiled fibers using an Er,Cr:YSGG laser emitting a train of pulses of 150 μs duration at a repetition frequency of 20 Hz producing 7.5 W average power. Large core fibers (450/510μm 0,2NA) are characterized by an attenuation of 0.02dB/m at 3μm and stay within 0.5°C from ambient temperature when carrying full laser power. A 2-m fiber length prepared with bare cleaves has been tested for over 23 hours, cumulating 1,140,000 shots of 1530 J/cm2 fluence while maintaining 90% transmission without any measurable degradation. Coiling the fiber to 11 cm radius did not have an impact on power handling reliability. These results show the potential of these highly transparent fibers in surgical laser delivery applications.

  20. Evaluation of fibroblast attachment in root conditioning with Er, Cr:YSGG laser versus EDTA: a SEM study.

    Fekrazad, Reza; Lotfi, Ghogha; Harandi, Mohammad; Ayremlou, Sara; Kalhori, Katayoun A M


    The regeneration of periodontal support is a main concern in periodontal therapy. This study aims to investigate the efficacy of Er, Cr:YSGG laser and EDTA based conditioning in attachment of fibroblast on root surfaces. This in vitro study was conducted on 81 root plates (6 mm × 4 mm × 1 mm) prepared from 27 single-rooted human mature teeth. The samples were divided into three groups: (1) Er, Cr: YSGG laser conditioning with a G6 tip (2.78 µm, 0.75 W, pulse duration of 140 µs, repetition rate of 20 Hz) for 5-7 s; (2) EDTA conditioning (17%, pH: 8) for 1 min; and (3) the control group which were exposed neither to EDTA nor laser. The viability and proliferation rates assessments were performed using MTT assay on days 3 and 5. In addition, the level of cell attachment was studied using scanning electron microscopy. The data indicated Er, Cr:YSGG conditioning increased cell viability by lapse of time (from days 3-5), with significantly better cell attachment compared to the other groups on days 3 and 5 (P EDTA conditioning group compared with the control group was statistically significant on day 5 but not on day 3 (P EDTA.

  1. Application of reflectance confocal microscopy to evaluate skin damage after irradiation with an yttrium-scandium-gallium-garnet (YSGG) laser.

    Yue, Xueping; Wang, Hongwei; Li, Qing; Li, Linfeng


    The objective of this study was to observe the characteristics of the skin after irradiation with a 2790-nm yttrium-scandium-gallium-garnet (YSGG) laser using reflectance confocal microscopy (RCM). A 2790-nm YSGG laser was used to irradiate fresh foreskin (four doses, at spot density 3) in vitro. The characteristics of microscopic ablative columns (MAC), thermal coagulation zone (TCZ), and microscopic treatment zones (MTZ) were observed immediately after irradiation using digital microscope and RCM. The characteristics of MAC, TCZ, and MTZ with variations in pulse energy were comparatively analyzed. After irradiation, MAC, TCZ, and MTZ characteristics and undamaged skin between MTZs can be observed by RCM. The depth and width of MTZ obviously increased with the increase in pulse energy. At 80, 120, and 160 mJ/microbeam (MB), the MTZ actual area and proportion were about two times that of the theoretical value and three times at 200 mJ/MB. With increases in depth, the single MAC gradually decreased in a fingertip-shaped model, with TCZ slowly increasing, and MTZ slightly decreasing in a columnar shape. RCM was able to determine the characteristics of thermal injury on the skin after the 2790-nm YSGG laser irradiation with different pulse energies. Pulse energy higher than 200 mJ/MB may have much larger thermal injury and side effect. RCM could be used in the clinic in future.

  2. Influence of Er,Cr:YSGG laser on CaF₂ -like products formation because of professional acidulated fluoride or to domestic dentifrice application.

    Zamataro, Claudia Bianchi; Ana, Patricia Aparecida; Benetti, Carolina; Zezell, Denise Maria


    This study evaluated the synergy of professional acidulated fluoride gel (APF) or fluoridated dentifrice application combined with Er,Cr:YSGG laser irradiation on the formation of CaF2 -like products (CaF2 ), in vitro. Thus, 272 bovine enamel slabs were randomly distributed among eight groups: G1: untreated enamel; G2: treated with fluoridated dentifrice (NaF, 1,100 μgF/g); G3: treated with acidulated phosphate fluoride gel (APF, 1.23% F(-) ); G4: irradiated with Er,Cr:YSGG laser at 8.5 J/cm(2) ; G5 and G6: combination of pre-irradiation with Er,Cr:YSGG followed by dentifrice or APF application, respectively; G7: combination of dentifrice application followed by Er,Cr:YSGG irradiation; G8: combination of APF application followed by Er,Cr:YSGG irradiation. After treatments, samples were evaluated by scanning electron microscopy, and the content of CaF2 was determined by an ion specific electrode. Both APF and dentifrice application promoted the formation of CaF2 on enamel, whereas Er,Cr:YSGG irradiation promoted an increase of roughness of the enamel, increasing the surface area. Laser irradiation before fluoridated products increased the content of CaF2 formed when compared to groups that APF or dentifrice were applied isolated. However, the content of CaF2 formed when irradiation was performed after APF or dentifrice was not statically significant when compared to the control groups. In conclusion, Er,Cr:YSGG laser increases the formation of CaF2 on enamel when the irradiation is performed before the application of APF or dentifrice. The association of laser with APF is most promissory for caries prevention because of the higher concentration of CaF2 formation and also the chemical changes promoted by laser irradiation demonstrated in literature. Copyright © 2013 Wiley Periodicals, Inc.

  3. Effect of Er,Cr:YSGG Laser Irradiation with Radial Firing Tips on Candida albicans in Experimentally Infected Root Canals

    Leman Ozkan


    Full Text Available Aim. To compare the disinfection effect of Er,Cr:YSGG laser using radial firing tips with NaOCI in root canals infected with C. albicans and to evaluate the irradiation effect on the dentinal surfaces. Material and Methods. In total seventy-six mandibular premolar teeth were used. In order to standardize the incubation and sterilization procedure, eight teeth were used. Sixty-eight of the root canals were incubated with C. albicans suspension for 72 hours. The specimens were divided into 5 experimental groups. Two groups were constituted as Group 1 was irradiated with 1.5 W laser (n=8 and group 2, which was irradiated with 2 W laser (n=8. Two more groups were formed as Group 3 (2 W laser (n=25 and Group 4 NaOCI (5% (n=25. Group 5 (n=2 did not receive any treatment. Mann-Whitney U and Kruskal-Wallis H tests were used to compare the different laser output powers. Wilcoxon Signed Ranks Test was used in order to compare the Candida cfu/ml levels according to treatment protocols (P<0.05. Results. Both 1.5 W and 2 W laser resulted in a major reduction of C. albicans without a significant difference. The comparison of the dentin surfaces irradiated with Er,Cr:YSGG laser at two power settings resulted in similar morphological changes. However, NaOCI was found to be more effective in reduction of C. albicans than 2 W laser application. Conclusion. According to the results of the present study, the Er,Cr:YSGG laser with radial firing tips presented less antifungal effects on C. albicans in root canals of infected teeth than NaOCl solution.

  4. Effect of Er,Cr:YSGG and Er:YAG laser irradiation on the adhesion of blood components on the root surface and on root morphology


    The aim of this study was to conduct an in vitro evaluation, by scanning electron microscopy (SEM), of the adhesion of blood components on root surfaces irradiated with Er,Cr:YSGG (2.78 mu m) or Er:YAG (2.94 mu m) laser, and of the irradiation effects on root surface morphology. Sixty samples of human teeth were previously scaled with manual instruments and divided into three groups of 20 samples each: G1 (control group) - no treatment; G2 - Er,Cr:YSGG laser irradiation; G3 - Er:YAG laser irr...

  5. Atomic force microscopy visualization of injuries in Enterococcus faecalis surface caused by Er,Cr:YSGG and diode lasers.

    López-Jiménez, Lidia; Arnabat-Domínguez, Josep; Viñas, Miguel; Vinuesa, Teresa


    To visualize by atomic force microscopy the alterations induced on Enterococcus. faecalis surface after treatment with 2 types of laser: Erbium chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser and Diode laser. Bacterial suspensions from overnight cultures of E. faecalis were irradiated during 30 seconds with the laser-lights at 1 W and 2 W of power, leaving one untreated sample as control. Surface alterations on treated E. faecalis were visualized by atomic force microscopy (AFM) and its surface roughness determined. AFM imaging showed that at high potency of laser both cell morphology and surface roughness resulted altered, and that several cell lysis signs were easily visualized. Surface roughness clearly increase after the treatment with Er,Cr:YSGG at 2W of power, while the other treatments gave similar values of surface roughness. The effect of lasers on bacterial surfaces visualized by AFM revealed drastic alterations. AFM is a good tool to evaluate surface injuries after laser treatment; and could constitute a measure of antimicrobial effect that can complete data obtained by determination of microbial viability.

  6. Composite resin bond strength to tooth structure treated with an erbium,chromium:YSGG-laser-powered hydrokinetic system

    Lin, Sean; Caputo, Angelo A.; Rizoiu, Ioana-Mihaela; Eversole, Lewis R.


    Er;YAG and Er,Cr;YSGG Lasers that emit in the near red wave lengths cut both enamel and dentine. Dental preparations are often restored with composite resins that bond to enamel. The purpose of this investigation was to assess the shear strength of composite resin bonded to tooth structure cut by an Er,Cr;YSGG powered hydrokinetic system (HKS), (Millennium SystemTM, BioLase Technology, Inc, San Clemente, CA) as compared to surfaces cut with a carbide bur. Extracted human molars devoid of caries and restorations were treated with both systems, with and without acid etching. Shear bond strengths (SBS) for composite resin adherence to these surfaces were measured and compared. There was no significant difference between bur and HKS prepared surfaces in the etched enamel group. The SBS for composite bonded to nonetched enamel was significantly higher with the HKS treatment compared with the bur cut surfaces. There were no significant differences between acid etched bur cut and non etched HKS enamel surfaces. Bonded to nonetched dentin was found to be higher for bur cut surfaces. It is concluded that the Er,Cr;YSGG hydrokinetic system produces surface characteristics that allow for adequate bonding of composite resin to both etched and nonetched enamel.

  7. Effect of EndoActivator and Er,Cr:YSGG laser activation of Qmix, as final endodontic irrigant, on sealer penetration: A Confocal microscopic study

    Yadav, Sudha; Talwar, Sangeeta; Verma, Mahesh


    Background Through chemomechanical debridement of the root canal is a primary requisite for successful endodontic therapy. Thus the aim of this study was to evaluate the effects of using QmiX alone, QmiX with EndoActivator and QmiX with Er,Cr:YSGG laser for final irrigation on sealer penetration into the dentinal tubules. Material and Methods 75 extracted human mandibular premolar teeth were treated with sodium hypochlorite (NaOCl) irrigation. The samples were divided into 5 groups according to the final irrigation solution used: (1) 17% EDTA and 2.5% NaOCl, (2) QmiX (3) QmiX with Er,Cr:YSGG laser and (4) QmiX with EndoActivator (5) 2.5%NaOCl. All teeth were obturated using cold lateral condensation technique with gutta percha and AH 26 sealer (Dentsply; DeTrey,Konstanz, Germany) labeled with Rhodamine B dye. The teeth were sectioned at distances of 2 and 5 from root apex. Total percentage and maximum depth of sealer penetration were measured using confocal laser scanning microscopy. Results Results of one way Anova analysis showed that there was a significant difference in the percentage and depth of sealer penetration among all groups at 3 and 5 mm level sections (P < .05). Within the groups maximum sealer penetration was recorded for Er,Cr:YSGG laser activated group. Greater depth of sealer penetration was recorded at 5mm as compared to 3mm in all the groups. Conclusions Activation of QMix using EndoActivator and Er,Cr:YSGG laser enhanced the sealer penetration at apical and middle third. Thus Er,Cr:YSGG laser and EndoActivator may act as an appropriate adjunct during chemomechanical preparation of the root canal. Key words:EndoActivator, Er,Cr:YSGG laser, Qmix, confocal microscopy, sealer penetration. PMID:28210439

  8. Effect of Er,Cr:YSGG laser on the surface of composite restoratives during in-office tooth bleaching.

    Dionysopoulos, Dimitrios; Strakas, Dimitrios; Tsitrou, Effrosyni; Tolidis, Kosmas; Koumpia, Effimia


    The aim of this in vitro study was to investigate the effect of Er,Cr:YSGG laser on the surface roughness and microhardness of various composite restoratives during in-office tooth bleaching. Five highly viscous composite restoratives and three flowable composite restoratives were investigated. Thirty cylindrical specimens of each material were made using Teflon molds. The specimens of each composite were randomly divided into three groups (n = 10). Group 1 specimens did not receive bleaching treatment, group 2 received a conventional in-office bleaching treatment, and group 3 received a laser-assisted in-office bleaching treatment using an Er,Cr:YSGG laser. Two-way ANOVA was used to determine significant interactions between materials and bleaching methods. One-way ANOVA and Tukey's post hoc test were used to compare the mean surface microhardness and roughness between materials for each treatment group (a = 0.05). Τhere were no significant differences in surface microhardness between the two bleached experimental groups for all the tested composites (p > 0.05). The reduction of surface microhardness after bleaching procedures ranged from 0.72 to 16.93 % for the specimens received conventional treatment and from 1.30 to 11.51 % for those received laser-assisted treatment. Moreover, there were no significant differences in Ra values between the experimental groups (p > 0.05) in all cases. The increase of surface roughness after the bleaching treatments was negligible and was between 0.43 and 4.78 %. The use of Er,Cr:YSGG laser during in-office tooth bleaching treatment did not affect the surface microhardness and roughness of the tested composite restorative materials.

  9. The effect of Nd:YAG and Er,Cr:YSGG lasers on the microhardness of human dentin.

    Al-Omari, Wael M; Palamara, Joseph E


    The current investigation determined the microhardness of dentin tissue irradiated with erbium, chromium-doped yttrium scandium gallium garnet (Er,Cr:YSGG) and neodymium-doped yttrium-aluminum garnet (Nd:YAG) lasers. Thirty non-carious human molars were used in this study. Dentin disks were prepared by horizontal sectioning of one third of the occlusal surface. Halves of dentin specimens were irradiated with 3.5- and 4.5-W Er,Cr:YSGG lasers and with a 2-W Nd:YAG laser. The remaining halves served as controls. The microhardness measurements were recorded with a Vickers surface microhardness tester. The results were statistically evaluated by paired t test and one-way ANOVA (p = 0.05). Laser irradiation has significantly reduced the microhardness of dentin within each group compared to its control. Moreover, statistically significant differences were observed among the different groups (p microhardness of dentin followed by 4.5 W and Nd:YAG laser. The differences between all the groups were statistically significant. It was concluded that both laser devices used in this study have resulted in significant thermal damage and subsequent reduction in dentin microhardness values.

  10. Short-term clinical outcomes of laser supported periodontal treatment concept using Er,Cr:YSGG (2780nm) and diode (940 nm): a pilot study

    Odor, Alin A.; Violant, Deborah; Badea, Victoria; Gutknecht, Norbert


    Backgrounds: Er,Cr:YSGG (2780nm) and diode (940 nm) lasers can be used adjacent to the conventional periodontal treatment as minimally invasive non-surgical devices. Aim: To describe the short-term clinical outcomes by combining Er,Cr:YSGG (2780nm) and diode 940 nm lasers in non-surgical periodontal treatment. Materials and methods: A total of 10 patients with periodontal disease (mild, moderate, severe) - 233 teeth and 677 periodontal pockets ranging from 4 mm to 12 mm - were treated with Er,Cr:YSGG (2780nm) and diode (940 nm) lasers in adjunct to manual and piezoelectric scaling and root planning (SRP). Periodontal parameters such as mean probing depth (PD), mean clinical attachment level (CAL) and mean bleeding on probing (BOP) were evaluated at baseline and 6 months after the laser treatment using an electronic periodontal chart. Results: At baseline, the mean PD was 4.06 ± 1.06 mm, mean CAL was 4.56 ± 1.43 mm, and mean BOP was 43.8 ± 23.84 %. At 6 months after the laser supported periodontal treatments the mean PD was 2.6 ± 0.58 mm (p periodontal clinical parameters such as PD, CAL and BOP. Keywords: Laser supported periodontal treatment concept, Er,Cr:YSGG and diode 940nm lasers, Scaling and root planning, Minimally invasive non-surgical device

  11. Microtensile bond strength analysis of adhesive systems to Er:YAG and Er,Cr:YSGG laser-treated dentin.

    Ramos, Thaysa Monteiro; Ramos-Oliveira, Thayanne Monteiro; Moretto, Simone Gonçalves; de Freitas, Patricia Moreira; Esteves-Oliveira, Marcella; de Paula Eduardo, Carlos


    The aim of this in vitro study was to evaluate the effect of different surface treatments (control, diamond bur, erbium-doped yttrium aluminum garnet (Er:YAG) laser, and erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser) on sound dentin surface morphology and on microtensile bond strength (μTBS). Sixteen dentin fragments were randomly divided into four groups (n = 4), and different surface treatments were analyzed by scanning electron microscopy. Ninety-six third molars were randomly divided into eight groups (n = 12) according to type of surface treatment and adhesive system: G1 = Control + Clearfil SE Bond (SE); G2 = Control + Single Bond (SB); G3 = diamond bur (DB) + SE; G4 = DB + SB, G5 = Er:YAG laser (2.94 μm, 60 mJ, 2 Hz, 0.12 W, 19.3 J/cm(2)) + SE; G6 = Er:YAG + SB, G7 = Er,Cr:YSGG laser (2.78 μm, 50 mJ, 30 Hz, 1.5 W, 4.5 J/cm(2)) + SE; and G8 = Er,Cr:YSGG + SB. Composite blocks were bonded to the samples, and after 24-h storage in distilled/deionized water (37 °C), stick-shaped samples were obtained and submitted to μTBS test. Bond strength values (in megapascal) were analyzed by two-way ANOVA and Tukey tests (α = 0.05). G1 (54.69 ± 7.8 MPa) showed the highest mean, which was statistically significantly higher than all the other groups (p systems did not differ statistically from each other. Based on the irradiation parameters considered in this study, it can be concluded that Er:YAG and Er,Cr:YSGG irradiation presented lower values than the control group; however, their association with self-etching adhesive does not have a significantly negative effect on sound dentin (μTBS values of >20 MPa).

  12. Laser Supported Reduction of Specific Microorganisms in the Periodontal Pocket with the Aid of an Er,Cr:YSGG Laser: A Pilot Study

    N. Gutknecht


    Full Text Available Objective. The aim of this study was to evaluate the effectiveness of a radial firing tip of an Er,Cr:YSGG laser as an adjunct to a nonsurgical periodontal treatment. Methods. Twelve patients with chronic or aggressive periodontitis were treated by conventional periodontal treatment using ultrasonic devices and hand instruments and, additionally, in two quadrants with an Er,Cr:YSGG laser. A new radial firing tip (RFPT 14-5, Biolase was used with 1.5 W, 30 Hz, 11% air, 20% water, and pulse duration 140 μs. Microbiological smears were taken before treatment, one day after lasing, and three and six months after lasing. Pocket depths of all periodontal sites were measured before and six months after treatment. Results. The total bacterial load of Prevotella intermedia, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans inside the pocket was reduced significantly throughout the whole examination time. Greater pocket depth reductions were observed in all groups. There was a slight higher reduction of pocket depth in the lased group after six months. Conclusions. These results support the thesis that Er,Cr:YSGG laser supported periodontal treatment leads to a significant reduction of periopathogenes and thereby helps the maintenance of periodontal health.

  13. Comparison of shear bond strength of reattached incisor fragment using Er,Cr:YSGG laser etching and conventional acid etching: An in vitro study

    Kumar, Gyanendra; Goswami, Mridula; Dhillon, Jatinder Kaur


    Aim: The aim of this invitro study is to evaluate the shear bond strength of reattached fractured incisor fragments using Er,Cr:YSGG laser and conventional acid etching without additional tooth preparation. Materials and methods: Forty extracted human teeth were divided in two groups of 20 each (Groups A and B). In Group A, fractured surface was treated by an Er, Cr: YSGG laser system (Waterlase MD, Biolase Technology Inc., San Clemente, CA, USA) operating at a wavelength of 2,780 nm and frequency of 20 Hz. In Group B, fractured surface was etched using 37% phosphoric acid (Scotchbond, 3M). In both the groups, further subdivision with 10 sample each was made based on horizontal and oblique fracture. After laser or acid etching, all the samples were reattached using flowable composite resin and light cured. The samples were tested for shear bond strength. Results: Mean shear bond strength for Group A (94.70±39.158) was lower as compared to Group B (121.25±49.937), although the difference was not statistically significant(p value=0.121). Similarly no statistical significant difference was observed amongst the subgroups. (p>0.05) Conclusion: Er,Cr:YSGG laser etching in reattachment of fractured incisor fragment is a good alternative to conventional acid etching. Er,Cr:YSGG showed comparable efficiency in rebonding of fractured teeth fragment as acid etching. PMID:27721563

  14. Effect of Er,Cr:YSGG and Er:YAG laser irradiation on the adhesion of blood components on the root surface and on root morphology.

    Oliveira, Guilherme José Pimentel Lopes de; Theodoro, Letícia Helena; Marcantonio Junior, Elcio; Sampaio, José Eduardo Cezar; Marcantonio, Rosemary Adriana Chiérici


    The aim of this study was to conduct an in vitro evaluation, by scanning electron microscopy (SEM), of the adhesion of blood components on root surfaces irradiated with Er,Cr:YSGG (2.78 µm) or Er:YAG (2.94 µm) laser, and of the irradiation effects on root surface morphology. Sixty samples of human teeth were previously scaled with manual instruments and divided into three groups of 20 samples each: G1 (control group) - no treatment; G2 - Er,Cr:YSGG laser irradiation; G3 - Er:YAG laser irradiation. After performing these treatments, blood tissue was applied to 10 samples of each group, whereas 10 samples received no blood tissue application. After performing the laboratory treatments, the samples were observed under SEM, and the resulting photomicrographs were classified according to a blood component adhesion scoring system and root morphology. The results were analyzed statistically (Kruskall-Wallis and Mann Whitney tests, α= 5%). The root surfaces irradiated with Er:YAG and Er,Cr:YSGG lasers presented greater roughness than those in the control group. Regarding blood component adhesion, the results showed a lower degree of adhesion in G2 than in G1 and G3 (G1 × G2: p = 0.002; G3 × G2: p = 0.017). The Er:YAG and Er,Cr:YSGG laser treatments caused more extensive root surface changes. The Er:YAG laser treatment promoted a greater degree of blood component adhesion to root surfaces, compared to the Er,Cr:YSGG treatment.

  15. Successful use of 1064 Nm Nd:YAG in conjunction with 2790 Nm YSGG ablative laser for traumatic scarring.

    Nijhawan, Rajiv I; Perez, Maritza I


    Patients with traumatic scarring often seek both aesthetic and functional improvement and can be a challenge to treat; however, advances in laser and light technologies have helped to treat many of these patients with rather minimally invasive approaches. A nineteen year old girl with Fitzpatrick skin type III skin presented for the evaluation of extensive traumatic scarring involving her right cheek, right chin, and right oral commissure that she sustained after a motor vehicle accident. We report the successful use of the 1064 nm Nd:YAG laser in conjunction with the ablative 2790 nm YSGG laser for the treatment of traumatic scarring in this patient. Our patient noted a notable improvement in the appearance of her traumatic scarring in addition to decrease in contracture of the right oral commissure. The treatment regimen described provides an effective option for clinicians to utilize when treating traumatic scarring and skin textural changes.

  16. Microleakage of composite resin restoration in cavities prepared by Er,Cr:YSGG laser irradiation and etched bur cavities in primary teeth.

    Hossain, Mozammal; Nakamura, Yukio; Yamada, Yoshishige; Murakami, Yoshiko; Matsumoto, Koukichi


    In this in vitro study, the surface alterations of enamel and dentin in cavities prepared by Er,Cr:YSGG laser irradiation was investigated by scanning electron microscopy and compared to the microleakage degree after composite resin restoration with etched bur cavities in human primary teeth. The results confirmed that laser cavity surface facilitated a good adhesion with the restorative materials; the acid etch step can be easily avoided with the laser treatment.

  17. Bond Strength of Abraded and Non-Abraded Bleached Enamel to Resin After Er,Cr:YSGG Laser Irradiation.

    Oliveira, Pedro H C; Cassoni, Alessandra; Brugnera, Aldo; Tenório, Ilana P; Rodrigues, José A


    The objective of the study was to evaluate the microtensile bond strength (μTBS) of a composite resin to abraded or non-abraded bleached enamel after Er,Cr:YSGG laser irradiation and to observe the fracture patterns of the tested interfaces. Two hundred twenty-eight bovine incisors were sectioned, resulting in 228 enamel blocks (7 × 4 × 4 mm(3)) that were divided into 12 groups (n = 19) according to the factors "adhesion" after bleaching (immediate adhesion; after 14 days; and a control group with adhesion on unbleached teeth); enamel "abrasion" (with or without abrasion simulating cavity preparation); and "laser" (with or without Er,Cr:YSGG laser irradiation). Bleached enamel groups were treated with 20% carbamide peroxide, 8 h/day for 21 days. Abrasion was performed with silicon carbide sandpaper. Specimens were restored with adhesive system and a composite resin (Adper Single Bond 2 and Z250; 3M ESPE). After 7 days, specimens were prepared by cutting into 1 mm beans to μTBS test performed in a universal testing machine. Fracture mode analysis was performed by using a stereoscopic loupe. The μTBS data were statistically analyzed by three-way analysis of variance with 95% confidence level and compared by running a Tukey post hoc test (α = 0.05). There was no statistically significant difference between triple interaction and double interactions among factors. There was no significant difference between the factors "adhesion," "abrasion," and "laser." Laser irradiation produced significantly lower bond strength values in irradiated groups compared with the non-irradiated ones. All groups had a high percentage of adhesive failures. Abrasion provided no benefit to bond strength of composite resins to bleached enamel. Er,Cr:YSGG (20 Hz, 0.5 W, 3.97 J/cm(2)) treatment reduced the bond strength of composite resins to enamel.

  18. Comparison of the sealing ability of two root-end filling materials (MTA and CEM cement following retropreparation with ultrasonic or Er,Cr:YSGG laser

    Razmi H


    Full Text Available "nBackground and Aims: Considering advantages and disadvantages of mineral trioxide aggregate (MTA, Calcium Enriched Mixture (CEM cement has been developed recently. The purpose of this study was to compare the apical microleakage of the root-end cavities prepared by ultrasonic or Er,Cr:YSGG laser and filled with MTA or CEM cement. "nMaterials and Methods: Eighty single-rooted, extracted human teeth were instrumented and obturated. Root-end resection was made by removing 3 mm of the apex. The teeth were randomly divided into two experimental (n=30 and two positive and negative control (n=10 groups. After that, the retrograde cavities were prepared using ultrasonic or Er,Cr: YSGG Laser. According to the root-end filling materials (MTA or CEM cement, each group was then divided into two subgroups. Finally, specimens were cleared for assessing the amount of apical dye (Indian ink penetration. The data were analyzed using Kruskall-Wallis and Dunn tests. "nResults: Laser/CEM cement group showed significantly the lowest mean apical dye penetration. There were no statistically significant differences between Laser/MTA, ultrasonic/MTA and ultrasonic/CEM cement groups. "nConclusion: Based on the findings of this study, CEM cement demonstrated lower rate of apical leakage compared with MTA, when the root-end cavities prepared with Er,Cr:YSGG Laser. The sealing ability of MTA was not different following root-end preparation by ultrasonic or Er,Cr:YSGG Laser.

  19. Conditioning effects of cavities prepared with an Er,Cr:YSGG laser and an air-turbine.

    Kato, Chikage; Taira, Yoshihisa; Suzuki, Masaya; Shinkai, Koichi; Katoh, Yoshiroh


    The purpose of this study was to examine, morphologically and histochemically, five types of conditioning effects on cavities prepared with an Er,Cr:YSGG laser and an air-turbine. Cavities were prepared using a Waterlase(®) MD turbo handpiece (W) and an air-turbine (AT) on human extracted molars. The cavity conditionings used were non-conditioned (G1), K-etchant Gel (G2), K-etchant Gel + AD Gel (G3), Clearfil SE Bond primer (G4) and Clearfil S(3) Bond (G5). On naked eye observations, enamel of G1, G2 and G3 in the W cavities and etched enamel of G2 and G3 in the AT cavities were observed as rough and dull in appearance. G4 and G5 in W and AT cavities were observed as shiny surfaces. On SEM observations, no smeared layer was observed in W cavities, while a smeared layer and bur-scratches were observed in AT cavities. In W cavities, rough surfaces were observed on enamel. That is, cracks and minute rough surfaces were observed. In contrast, equally etched scale-shaped enamel rods were observed in AT cavities. Widely opened dentinal tubules and protruding peritubular matrices of dentin were observed in W cavities. A few remaining smeared plugs could be observed at the AT cavities. On LM observations, 13-16 μm layers of the dentin in G1, G2, G4 and G5 of W cavities were stained red in color by the Azan staining method, while redness was not observed in G3. No groups were stained red in AT cavities. It was considered that layers stained red in color were thermal degeneration layers of dentin induced by W. Namely 30 s etching of 40% phosphoric acid gel followed by 90 s treatment of 10% NaClO gel should be recommended for use when combined with an Er,Cr:YSGG laser for cavity preparation.

  20. The effect of Er,Cr:YSGG laser application on the micropush-out bond strength of fiber posts to resin core material.

    Kurtulmus-Yilmaz, Sevcan; Cengiz, Esra; Ozan, Oguz; Ramoglu, Serhat; Yilmaz, Hasan Guney


    The aim of this study was to compare the effects of erbium, chromium: yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser application to different surface treatments on the micropush-out bond strengths between glass and quartz fiber posts and composite resin core material. Different types of lasers have been used as an alternative to airborne particle abrasion and other surface treatment methods to enhance the bond strength of dental materials. However, there is no study regarding the use of Er,Cr:YSGG laser as a surface treatment method for fiber posts in order to improve the bond strength. Ninety-six quartz and 96 glass fiber posts with a coronal diameter of 1.8 mm were randomly divided into eight groups according the surface treatments applied. Gr 1 (control, no surface treatment), Gr 2 (sandblasting with 50 μm Al2O3), Gr 3 (9 % hydrofluoric acid for 1 min), Gr 4 (24% H2O2 for 1 min), Gr 5 (CH2Cl2 for 1 min), Gr 6 (1 W), Gr 7 (1.5 W), and Gr 8 (2 W) Er,Cr:YSGG laser irradiation. The resin core material was applied to each group, and then 1 mm thick discs (n=12) were obtained for the micropush-out test. Data were statistically analyzed. For the quartz fiber post group, all surface treatments showed significantly higher micropush-out bond strengths than the control group (pstrength between the post and core material. However, the hydroflouric acid group showed the lowest bond strength values. The type of post and surface treatment might affect the bond strength between fiber posts and resin core material; 1 W and 1.5 W Er,Cr:YSGG laser application improved adhesion at the post/core interface.

  1. Effects of Er,Cr:YSGG laser irradiation on the surface characteristics of titanium discs: an in vitro study.

    Ercan, Esra; Arin, Tuna; Kara, Levent; Çandirli, Celal; Uysal, Cihan


    Lasers are used to modify the surfaces of dental implants or to decontaminate exposed implant surfaces. However, research is lacking on whether the laser causes any change on the surfaces of titanium implants. We aimed to determine the effects of laser treatment on the surface characteristics of titanium discs. Nine discs were fabricated using grade-V titanium with resorbable blast texturing surface characteristics. The discs were irradiated with an erbium, chromium: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) laser under different experimental conditions (R1-9). Scanning electron microscopy was used to evaluate implant surface topography qualitatively, and a mechanical contact profilometer was used to evaluate surface roughness. The R3 and R5 parameters caused no measurable change. Minor cracks and grooves were observed in discs treated with the R1, R2, R4, R7 and R9 parameters. Major changes, such as melting, flattening and deep crack formation, were observed in discs subjected to R6 (2 W, 30 Hz, 2 mm. distance, 30 s) and R8 (3 W, 25 Hz, 2 mm. distance, 45 s) parameters. The lowest surface roughness value was obtained with the R8 parameter. Irradiation distance, duration, frequency and power were the most significant factors affecting surface roughness. Parameters such as wavelength, output power, energy, dose and duration should be considered during irradiation. The results of this study indicate that the distance between the laser tip and the irradiated surface should also be considered.

  2. Acoustic comparison of Er,Cr:YSGG laser and dental high speed handpiece for primary anterior tooth preparation

    Jorden, Monserrat; Chen, Jung-Wei; Easley, Elisabeth; Li, Yiming; Kurti, R. Steven

    The acoustics of a dental hard tissue laser (Er,Cr:YSGG laser, Waterlase MD, Biolase, USA) and a traditional dental high speed hand piece (Midwest®, Dentsply International, USA) were compared in vitro using a simple approach that can be easily adapted for in vivo studies. Thirty one extracted caries and restoration free primary anterior teeth were selected. These teeth were sectioned along a symmetry axis to give two identical halves for use in a split study. These halves were randomly assigned to either the laser (experimental) or the high speed (control) group. A miniature electret microphone was coupled to the sample using a polymer and used to collect the acoustic signal at the interface of the pulp chamber. This signal was captured periodically by a digitizing oscilloscope and multiple traces were stored for subsequent analysis. 2x1x1mm3 preparations were made according to manufacturers recommendations for the given method. Each cavity was prepared by the same clinician and calibration tests were performed to ensure consistency. The measurements indicated that the peak acoustic pressures as well as cumulative acoustic effects (due to duty cycle) were significantly higher (Phand piece than with the dental laser. Our study suggests the need for further investigations into the neurological implications of acoustic effects in dental patient care such as pain studies.

  3. High speed imaging of an Er,Cr:YSGG laser in a model of a root canal

    Verdaasdonk, Rudolf; Blanken, Jan; van Heeswijk, Hans; de Roode, Rowland; Klaessens, John


    Laser systems of various wavelengths and pulse characteristics have been introduced in dentistry. At present, the range of applications for the different systems is being investigated mainly differentiating between soft and hard tissue applications. For the preparation of root canals both hard and soft tissues are involved. Ideally, one would like to use one laser system for the whole treatment. In this study, we studied the characteristics of the pulsed 2,78 Er,Cr:YSGG laser (Biolase, Waterlase Millenium), in view of root canal cleaning and desinfection. The laser energy was fiber delivered with fiber tip diameters from 400 μm down to 200 μm. Special thermal and high speed imaging techniques were applied in a transparent model of a tapered root canal and slices cut from human teeth. High speed imaging revealed the dynamics of an explosive vapor bubble at the tip of the Er laser in water and the root canal model. Typically for Erbium lasers, within a time span of several hundred μs, a longitudinal bubble expanded to maximum size of 5 mm length and 2 mm diameter at 100 mJ and imploded afterwards. In the root canal, the explosive bubble created turbulent high speed water streaming which resects soft tissue from the hard tissue. Thermal imaging showed the dynamics of all lasers heating of the canal wall up to several mm depending on the wavelength and energy settings. The mechanism of smear layer removal and sterilization in the root canal, is attributed to cavitation effects induced by the pulsed laser. The heat generation into the dentine wall was minimal.

  4. Effectiveness of a new method of disinfecting the root canal, using Er, Cr:YSGG laser to kill Enterococcus faecalis in an infected tooth model.

    Licata, M E; Albanese, A; Campisi, G; Geraci, D M; Russo, R; Gallina, G


    Some lasers have demonstrated to provide effective disinfection when used as adjunctive device to the conventional treatment. The aim of this in vitro study was to determine the effectiveness of the erbium, chromium:yttrium scandium gallium garnet (Er, Cr:YSGG) laser by measuring its bactericidal effect inside the root canal experimentally colonized with Enterococcus faecalis. The laser was tested at different irradiation times (30 and 60 s) and energy of impulses (75 and 25 mJ). A total of 52 single-rooted extracted human teeth were endodontically prepared with rotary instrumentation. All were sterilized and inoculated with a suspension of E. faecalis (105 bacteria/ml). The teeth were randomized into three treatment (group 1, group 2, and group 3) and one control groups. In all groups, teeth were chemically irrigated with 5.25% sodium hypochlorite and 17% ethylenediaminetetraacetic acid. Groups 1 and 2 were also irradiated at 30 and 60 s, respectively, with an Er, Cr:YSGG laser at 75 mJ. Teeth of group 3 were treated with laser for 60 s at 25 mJ. Samples were processed to detect the presence of E. faecalis. For all groups, a bactericidal effect was observed. The use of laser at 75 mJ with an irradiation time of 30 and 60 s eliminated a percentage of 92.3 and 100% of E. faecalis, respectively. In the control group, a reduction of 92.3% was observed. Lower percentage of reduction (46.1%) was obtained in teeth treated with laser at 25 mJ for 60 s. No statistical differences were observed between the groups (P = 0.543, Fisher's exact test). The results indicated a bactericidal effect of Er, Cr:YSGG laser irradiation at the settings used in this study. The highest bactericidal effect of this laser was observed at 60 s of irradiation time, using an energy pulse of 75 mJ.

  5. Evaluation of Temperature Elevation During Root Canal Treatment with Dual Wavelength Laser: 2780 nm Er,Cr:YSGG and 940 nm Diode.

    Al-Karadaghi, Tamara Sardar; Gutknecht, Norbert; Jawad, Hussein A; Vanweersch, Leon; Franzen, Rene


    The purpose of this study was to evaluate the effects of dual wavelength (2780 nm Er,Cr:YSGG and 940 nm diode) laser with radial firing tip (RFT) on the external root surface and sub-surfaces, in terms of temperature changes during laser-assisted root canal treatment. A significant factor that may limit the use of lasers in endodontics is the possible thermal injury to tooth supporting structures. A total of 50 sound single-rooted extracted teeth were divided randomly into two groups (n = 25). Group A, irradiated with Er,Cr:YSGG laser at 1.06 W, 50 Hz, and 50 μs was a control group, and group B was irradiated with dual wavelength of Er,Cr:YSGG laser with the same settings as group A and a diode laser of 0.51 W at 4 ms and 10 ms pulse duration. K-type thermocouples were used to record temperature changes at the cervical, middle, and apical root thirds, on root surfaces and sub-surfaces, arising from delivery of laser energy through RFT. Temperature elevation in group B was significantly higher in the middle and apical thirds of the prepared samples than in group A (p surface region corresponding to a 1.48 mm dentin thickness, whereas a mean temperature increase of 7.72°C was recorded corresponding to dentin thickness of 0.95 mm. Within the studied parameters, the dual wavelength laser did not result in adverse thermal changes on the external root surface in vitro.

  6. Clinical evaluation of the Er,Cr:YSGG Laser therapy in the treatment of denture-related traumatic ulcerations: a randomized controlled clinical study.

    Kurtulmus-Yilmaz, Sevcan; Yilmaz, Hasan Guney; Tumer, Hayriye; Sadettinoglu, Koray


    The aim of this study was to evaluate the efficacy of Er,Cr:YSGG laser irradiation in reducing pain and on healing rate of traumatic ulcerations (TU) during a 2-week period after placement of new complete dentures. Denture-related TU are painful, and result in patient discomfort. Lasers are used in the treatment of different kinds of mucosal lesions; however, there are no published data available concerning the clinical outcome of the use of laser therapy in the treatment of TU. Thirty edentulous patients with newly fabricated complete dentures who subsequently developed one or more pairs of TU participated in this study. For each patient, ulcerations were randomly assigned to the test and control groups. In the test group, ulcerations were irradiated with Er,Cr:YSGG laser. In the control group, the same laser without laser emission was used. Pain was assessed with a visual analog scale (VAS). Healing of ulcerations (HU) was graded by a clinician. In the test group, laser irradiation provided significantly reduced pain immediately after treatment, and provided a significant healing effect 1 day after treatment, and these effects were maintained throughout the study. In the control group, baseline VAS scores were not statistically significant at baseline and 1 day after treatment, and HU scores were statistically significant 3, 7, and 14 days after treatment. Intergroup comparisons revealed that the differences in VAS and HU scores were statistically significant for all time periods after treatment, except for day 14. Based on these findings, it may be concluded that Er,Cr:YSGG laser is effective in the treatment of TU.

  7. 水激光在牙体牙髓病治疗中的应用%Application of Er,Cr,YSGG laser in restorative and endodontic treatment

    刘宁宁(综述); 何文喜(审校)


    The first ruby laser machine was invented in 1960 and laser was first applied to dental treatment in 1971.Afterward,extensive studies have been conducted on laser application in dentistry.In 2002,Er,Cr,YSGG laser/Waterlaser was approved by US Food and Drug Administration.Since then,Er,Cr,YSGG laser has been widely used for the treatment of dental diseases including dental caries,dentin hypersensitivity,pulpitis and apical periodonti-tis.It is used for the removal of caries,pulp capping or pulpotomy and root canal therapy.In this review,the applica-tion of Er,Cr,YSGG laser in restorative and endondontic treatment is summarized.%自1960年第一台红宝石激光器问世,1971年开始了激光在牙科中的应用。2002年美国FDA批准了水激光牙科治疗系统的临床应用。随着各种不同激光器的进一步研发,激光在口腔疾病治疗方面的应用研究也不断深入,其应用范围也越来越广泛。其中以治疗龋病、牙本质过敏症、盖髓术、牙髓切断术、根管治疗术以及牙周疾病的研究较多。为此,本文就水激光在牙体牙髓病治疗中的应用研究作一综述。

  8. Effect of Er,Cr:YSGG Laser at Different Output Powers on the Micromorphology and the Bond Property of Non-Carious Sclerotic Dentin to Resin Composites

    Wang, Weiguo; Jiao, Yang; Wang, Wanshan; Yang, Yanwei; Wei, Jingjing; Shen, Lijuan; Chen, Jihua


    Background The objective of this study was to investigate the influence of Er,Cr:YSGG laser irradiated at different powers on the micromorphology and the bonding property of non-carious sclerotic dentin to resin composites. Methods Two hundred bovine incisors characterized by non-carious sclerotic dentin were selected, and the seventy-two teeth of which for surface morphological analysis were divided into nine groups according to various treatments (A: the control group, B: only treated with the adhesive Adper Easy One, C: diamond bur polishing followed by Adper Easy One, D-I: Er,Cr:YSGG laser irradiating at 1W, 2W, 3W, 4W, 5W, 6W output power, respectively, followed by Adper Easy One). The surface roughness values were measured by the non-contact three-dimensional morphology scanner, then the surface micromorphologies of surfaces in all groups were assessed by scanning electron microscopy (SEM); meanwhile, Image Pro-Plus 6.0 software was used to measure the relative percentage of open tubules on SEM images. The rest, one hundred twenty-eight teeth for bond strength test, were divided into eight groups according to the different treatments (A: only treated with the adhesive Adper Easy One, B: diamond bur polishing followed by the above adhesive, C-H: Er,Cr:YSGG laser irradiating at 1 W, 2 W, 3 W, 4 W, 5 W, 6 W output power, respectively, followed by the above adhesive), and each group was subsequently divided into two subgroups according to whether aging is performed (immediately tested and after thermocycling). Micro-shear bond strength test was used to evaluate the bond strength. Results The 4W laser group showed the highest roughness value (30.84±1.93μm), which was statistically higher than the control group and the diamond bur groups (pcarious sclerotic dentin and resin composites by increasing the roughness and mean percentage area of open tubules. PMID:26544034

  9. The influence of a novel in-office tooth whitening procedure using an Er,Cr:YSGG laser on enamel surface morphology.

    Dionysopoulos, Dimitrios; Strakas, Dimitrios; Koliniotou-Koumpia, Eugenia


    The purpose of this in vitro study was to evaluate the influence of a novel in-office tooth whitening procedure using Er,Cr:YSGG laser radiation on bovine enamel. Forty-eight enamel specimens were prepared from bovine canines and divided into four groups: Group 1 specimens (control) received no whitening treatment; Group 2 received whitening treatment with an at-home whitening agent (22% carbamide peroxide) for 7 days; Group 3 received whitening treatment with a novel in-office whitening agent (35% H(2)O(2)); Group 4 received the same in-office whitening therapy with Group 3 using Er,Cr:YSGG laser in order to accelerate the whitening procedure. The specimens were stored for 10 days after the whitening treatment in artificial saliva. Vickers hardness was determined using a microhardness tester and surface roughness was evaluated using a VSI microscope. Three specimens of each experimental group were examined under SEM and the mineral composition of the specimens was evaluated using EDS. Data were statistically analyzed using one-way ANOVA, Tukey's post-hoc test, Wilcoxon signed rank and Kruskal-Wallis tests (a = 0.05). The surface microhardness of the enamel was reduced after the in-office whitening treatments (Ptreatment (P> 0.05). Moreover, the surface roughness was not significantly changed after tooth whitening. EDS analysis did not show alterations in the enamel mineral composition, while SEM observations indicated changes in the surface morphology, especially after in-office tooth whitening (Plaser-assisted whitening treatment with Er,Cr:YSGG laser did not affect the alterations in enamel surface compared with the conventional in-office whitening technique. © 2015 Wiley Periodicals, Inc.

  10. Comparison of the Er,Cr:YSGG laser with a chemical vapour deposition bur and conventional techniques for cavity preparation: a microleakage study.

    Yazici, A Rüya; Yıldırım, Zeren; Antonson, Sibel A; Kilinc, Evren; Koch, Daniele; Antonson, Donald E; Dayangaç, Berrin; Ozgünaltay, Gül


    The aim of this study was to compare the effects of the Er,Cr:YSGG laser using chemical vapour deposition (CVD) bur cavity preparation with conventional preparation methods including a diamond bur and a carbide bur on the microleakage with two different adhesive systems. A total of 40 extracted human premolars were randomly assigned to four experimental groups according to the cavity preparation technique: group I diamond bur (Diatech); group II carbide bur (Diatech); group III Er,Cr:YSGG laser (Biolase Millennium II); and group IV CVD bur (CVDentUS). Using the different preparation techniques, Class V standardized preparations were performed on the buccal and lingual surfaces with gingival margins on the dentin and occlusal margins on the enamel. Each preparation group was randomly assigned to two subgroups (five teeth, ten preparations) according to the type of adhesive: an etch-and-rinse adhesive (Adper Single Bond), and a single-step self-etch adhesive (AdheSE One). All preparations were restored with a nanohybrid composite resin in a single increment. Following thermocycling (×500; 5-55°C), the teeth were immersed in basic fuchsin and sectioned in the orovestibular direction. Dye penetration was evaluated under a light microscope by two blinded examiners. Data were statistically analysed with the Kruskal-Wallis and Wilcoxon tests (p0.05). Comparing the enamel and dentin leakage scores within each group, no statistically significant differences were found (p>0.05). The Er,Cr:YSGG laser cavity preparation did not differ from preparation with CVD, diamond or carbide bur in terms of microleakage with the different adhesive systems.

  11. Fracture Forces of Dentin after Surface Treatment with High Speed Drill Compared to Er:YAG and Er,Cr:YSGG Laser Irradiation.

    Franzen, Rene; Kianimanesh, Nasrin; Marx, Rudolf; Ahmed, Asma; Gutknecht, Norbert


    Dental tooth restorative procedures may weaken the structural integrity of the tooth, with the possibility of leading to fracture. In this study we present findings of coronal dentin strength after different techniques of surface modification. The fracture strength of dentin beams after superficial material removal with a fine diamond bur high speed drill hand piece, Er:YAG (2.94 μm, 8 J/cm(2)), and Er,Cr:YSGG (2.78 μm, 7.8 J/cm(2)) laser irradiation slightly above the ablation threshold was measured by a four-point bending apparatus. Untreated dentin beams served as a control. A total of 58 dentin beams were manufactured from sterilized human extracted molars using the coronal part of the available dentin. Mean values of fracture strength were calculated as 82.0 ± 27.3 MPa for the control group (n = 10), 104.5 ± 26.3 MPa for high speed drill treatment (n = 10), 96.1 ± 28.1 MPa for Er,Cr:YSGG laser irradiation (n = 20), and 89.1 ± 36.3 MPa for Er:YAG laser irradiation (n = 18). Independent Student's t-tests showed no significant difference between each two groups (p > 0.05). Within the parameter settings and the limits of the experimental setup used in this study, both lasers systems as well as the high speed drill do not significantly weaken coronal dentin after surface treatment.

  12. Hard tooth tissue removal by short and long Er:YAG or Er,Cr:YSGG mid-infrared laser radiation

    Jelínková, H.; Dostálová, T.; Remeš, M.; Šulc, J.; Němec, M.; Fibrich, M.


    Hard dental tissue removal by laser radiation is an alternative treatment to conventional dental-drilling procedures. The advantages of this therapy are fast and localized treatment of hard dental tissue and painlessness. The most effective systems for those purposes are Er-lasers generating radiation at wavelengths of around 3 μm. The aim of this study was qualitative and quantitative examination of human dentin and ivory tissue removal by pulsed free-running (FR) and Q-switched (QSW) Er:YAG and Er,Cr:YSGG laser radiations. From the obtained results it follows that generally Er:YAG laser has lower threshold for the tissue removal in both FR and QSW regimes. Furthermore, the FR Er:YAG and Er,Cr:YSGG radiation can be effective for both dentin and ivory ablation and can prepare smooth cavities without side effects. The QSW regime is useful preferably for precise ablation of a starting tooth defect and for the part of the tooth very close to the gum. This regime is excellent for micro-preparation or for tooth treatment of children.

  13. Micromorphology analysis and bond strength of two adhesives to Er,Cr:YSGG laser-prepared vs. bur-prepared fluorosed enamel.

    Shafiei, Fereshteh; Jowkar, Zahra; Fekrazad, Reza; Khalafi-Nezhad, Abolfazl


    Preservation of enamel during composite veneer restorations of fluorosed teeth could be achieved by conservative preparation with Erbium lasers. This study evaluated the effect of fluorosed enamel preparation with Er,Cr:YSGG vs. conventional diamond bur on the micromorphology and bond strength of a self-etch and an etch-and-rinse adhesives. Er,Cr:YSGG laser or diamond bur preparation was performed on the flattened midbuccal surfaces of 70 extracted human premolars with moderate fluorosis (according to Thylstrup and Fejerskov index, TFI = 4-6). Adper Single Bond (SB) with acid etching for 20 or 40 s and Clearfil SE Bond (SEB) alone or with additional etching was applied in four laser groups. The same adhesive procedures were used in three bur groups except for 40 s of etching along with SB. After restoration, microshear bond strength was measured (MPa). Data were analyzed using ANOVA and Tamhane tests (α = 0.05). Six additional specimens were differently prepared and conditioned for scanning electron microscopy evaluation. The highest and lowest bond strengths were obtained for bur-prepared/SB (39.5) and laser-prepared/SEB (16.9), respectively, with a significant difference (P = 0.001). The different adhesive procedures used associated to two adhesives exhibited insignificantly lower bonding in laser-prepared groups compared to bur-prepared ones (P > 0.05), with the exception of additional etching/SEB, which bonded significantly higher to bur-prepared (36.4) than to laser-prepared enamel (18.7, P = 0.04). Morphological analyses revealed a delicate etch pattern with exposed enamel prisms on laser-prepared fluorosed enamel after acid etching and less microretentive pattern after self-etching primer. The etch-and-rinse adhesive was preferred in the laser-prepared fluorosed enamel in terms of bonding performance.

  14. Push-out bond strength of two root-end filling materials in root-end cavities prepared by Er,Cr:YSGG laser or ultrasonic technique.

    Shokouhinejad, Noushin; Razmi, Hasan; Fekrazad, Reza; Asgary, Saeed; Neshati, Ammar; Assadian, Hadi; Kheirieh, Sanam


    This study compared the push-out bond strength of mineral trioxide aggregate (MTA) and a new endodontic cement (NEC) as root-end filling materials in root-end cavities prepared by ultrasonic technique (US) or Er,Cr:YSGG laser (L). Eighty single-rooted extracted human teeth were endodontically treated, apicectomised and randomly divided into four following groups (n = 20): US/MTA, US/NEC, L/MTA and L/NEC. In US/MTA and US/NEC groups, root-end cavities were prepared with ultrasonic retrotip and filled with MTA and NEC, respectively. In L/MTA and L/NEC groups, root-end cavities were prepared using Er,Cr:YSGG laser and filled with MTA and NEC, respectively. Each root was cut apically to create a 2 mm-thick root slice for measurement of bond strength using a universal testing machine. Then, all slices were examined to determine the mode of bond failure. Data were analysed using two-way anova. Root-end filling materials showed significantly higher bond strength in root-end cavities prepared using ultrasonic technique (US/MTA and US/NEC) (P ultrasonically prepared cavities. © 2010 The Authors. Australian Endodontic Journal © 2010 Australian Society of Endodontology.

  15. Evaluation of microshear bond strength of resin composites to enamel of dental adhesive systems associated with Er,Cr:YSGG laser

    Cassimiro-Silva, Patricia F.; Zezell, Denise M.; Monteiro, Gabriela Q. d. M.; Benetti, Carolina; de Paula Eduardo, Carlos; Gomes, Anderson S. L.


    The aim of this in vitro study was to evaluate the microshear bond strength (μSBS) of resin composite to enamel etching by Er,Cr:YSGG laser with the use of two differents adhesives systems. Fifty freshly extracted human molars halves were embedded in acrylic resin before preparation for the study, making a total of up to 100 available samples. The specimens were randomly assigned into six groups (η=10) according to substrate pre-treatment and adhesive system on the enamel. A two-step self-etching primer system (Clearfil SE Bond) and a universal adhesive used as an etch-andrinse adhesive (Adper Single Bond Universal) were applied to the nonirradiated enamel surface according to manufacturer's instructions, as control groups (Control CF and Control SB, respectively). For the other groups, enamel surfaces were previously irradiated with the Er,Cr:YSGG laser with 0.5 W, 75 mJ and 66 J/cm2 (CF 5 Hz and SB 5 Hz) and 1.25 W, 50 mJ and 44 J/cm2 (CF 15 Hz and SB 15 Hz). Irradiation was performed under air (50%) and water (50%) cooling. An independent t-test was performed to compare the adhesive systems. Mean μSBS ± sd (MPa) for each group was 16.857 +/- 2.61, 17.87 +/- 5.83, 12.23 +/- 2.02, 9.88 +/- 2.26, 15.94 +/- 1.98, 17.62 +/- 2.10, respectively. The control groups and the 50 mJ laser groups showed no statistically significant differences, regardless of the adhesive system used. The results obtained lead us to affirm that the bonding interaction of adhesives to enamel depends not only on the morphological aspects of the dental surface, but also on the characteristics of the adhesive employed and the parameters of the laser.

  16. Fracture Forces of Dentin after Surface Treatment with High Speed Drill Compared to Er:YAG and Er,Cr:YSGG Laser Irradiation

    Rene Franzen


    Full Text Available Dental tooth restorative procedures may weaken the structural integrity of the tooth, with the possibility of leading to fracture. In this study we present findings of coronal dentin strength after different techniques of surface modification. The fracture strength of dentin beams after superficial material removal with a fine diamond bur high speed drill hand piece, Er:YAG (2.94 μm, 8 J/cm2, and Er,Cr:YSGG (2.78 μm, 7.8 J/cm2 laser irradiation slightly above the ablation threshold was measured by a four-point bending apparatus. Untreated dentin beams served as a control. A total of 58 dentin beams were manufactured from sterilized human extracted molars using the coronal part of the available dentin. Mean values of fracture strength were calculated as 82.0±27.3 MPa for the control group (n=10, 104.5±26.3 MPa for high speed drill treatment (n=10, 96.1±28.1 MPa for Er,Cr:YSGG laser irradiation (n=20, and 89.1±36.3 MPa for Er:YAG laser irradiation (n=18. Independent Student’s t-tests showed no significant difference between each two groups (p>0.05. Within the parameter settings and the limits of the experimental setup used in this study, both lasers systems as well as the high speed drill do not significantly weaken coronal dentin after surface treatment.

  17. Treatment of amalgam tattoo with an Er,Cr:YSGG laser.

    Yilmaz, Hasan Guney; Bayindir, Hakan; Kusakci-Seker, Basak; Tasar, Simge; Kurtulmus-Yilmaz, Sevcan


    Amalgam tattoos are common, asymptomatic, pigmented oral lesions that clinically exist as isolated, blue, gray, or black macules on the gingival, buccal, and alveolar mucosae, the palate, and/or the tongue. In this case report, the successful use of an erbium, chromium-doped:yttrium, scandium, gallium, and garnet laser for the removal of an amalgam tattoo is explained. A 46-year-old man is presented with a half decade history of an amalgam tattoo on his left maxillary premolar-molar gingiva. Depigmentation procedure was performed under topical anesthesia with the use of an erbium, chromium-doped:yttrium, scandium, gallium, and garnet laser at 2 W in the soft tissue pulsed mode for 10 min. The pigmented tissue was completely removed. The de-epithelialization area healed completely on the 10th day after treatment. The period of healing was uneventful. The amalgam tattoo was completely removed with erbium, chromium-doped:yttrium, scandium, gallium, and garnet laser, and the treated area healed without any adverse effect.

  18. Evaluation of Er,Cr:YSGG Laser Effect on Microshear Bond Strength of a Self-Adhesive Flowable Composite in the Dentin of Permanent Molar: An In Vitro Study

    Masoumeh Moslemi; Faezeh Fotouhi Ardakani; Fatemeh Javadi; Zahra Khalili Sadrabad; Zahra Shadkar; Mohammad Saeid Shadkar


    Aim and Background. Recently, new restorative materials such as self-adhesive flowable composites, because of their simple use and no need to bonding and etching, are considered important, particularly in pediatric dentistry. The aim of this study is to evaluate the effect of Er,Cr:YSGG laser on microshear bond strength of self-adhesive flowable composite on permanent teeth dentin in vitro. Material and Methods. In this experimental study, 40 dentin sections were prepared from healthy third m...

  19. Nano- and picosecond 3 μm Er: YSGG lasers using InAs as passive Q-switchers and mode-lockers

    Vodopyanov, K. L.; Lukashev, A. V.; Phillips, C. C.


    Recent results are reported using ultra-thin molecular beam epitaxy (MBE)-grown InAs epilayers on GaAs substrates as passive shutters for 3 μm Er: YSGG lasers ( λ = 2.8 μm). The laser photon energy is 27% higher than the InAs bandgap at 300 K and bleaching occurs due to a band filling effect with a fast recovery time of < 100 ps. Depending on the resonator geometry two modes of operation can be achieved: Q-switched with pulse duration of 35 ns and 5-6 mJ energy (TEM 00 mode) and a Q-switched/mode-locked regime with an output in the form of a train of 30 pulses separated by a 4.3 ns interval, 0.25 mJ energy per spike and 30-50 ps pulse duration in a TEM 00-mode. The latter are the shortest pulses obtained with this lasing medium to date.

  20. Assessment of Microleakage of a Composite Resin Restoration in Primary Teeth Following Class III Cavity Preparation Using Er, Cr: YSGG laser: An In Vitro Study

    Subramaniam, Priya; Pandey, Annu


    Introduction: Marginal seal integrity is important for a successful adhesive dental restoration. Alterations caused by laser irradiation in the enamel and dentin surface can affect the marginal integrity of adhesive restorations. The aim of this study was to evaluate the microleakage of a composite resin restoration in primary teeth following laser irradiation of enamel and dentin. Methods: Forty freshly extracted sound human primary maxillary and mandibular anterior teeth were used in this study. The teeth were randomly divided into two groups (I and II), with 20 teeth in each. In group I, proximal cavities (Class III) were prepared using an airotor hand –piece and diamond bur. The cavities were etched for 15 seconds with 35% phosphoric acid gel, rinsed with water for 15 seconds, air dried and a bonding agent was applied onto the cavity surfaces and light cured for 20 seconds. The cavities were restored with composite resin and light cured for 40 seconds. In group II, proximal (Class III) cavities were prepared using Erbium, Chromium: Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) (Er,Cr:YSGG) (Biolaseiplus, wave length 2.78 μm). The cavity was then rinsed, air dried and without etching, a bonding agent was applied and light cured for 20 seconds. The cavities were restored in the same manner as that of group I. The treated teeth were mounted on acrylic resin blocks and were subjected to a thermocycling regimen. Following, the teeth were immersed in 2% methylene blue for 24 hours. The teeth were sectioned longitudinally in a bucco-lingual direction using a diamond disc at slow speed. The sections of all the groups were examined under a stereomicroscope for micro-leakage. Results: The mean scores for microleakage in group I was 1.95 ± 1.31 and in group II it was 1.4 ± 1.27. There was no significant difference between the two groups (P = 0.882). Conclusion: No significant difference in microleakage was noticed between the composite resin bonded to lased enamel and

  1. Evaluation of Root-End Resections Performed by Er, Cr: YSGG Laser with and without Placement of a Root-End Filling Material

    John Sullivan


    Full Text Available Microleakage following root-end resections has a direct influence on the outcome of surgical endodontic procedures. This study compared the microleakage after root-end resections performed by the Er, Cr: YSGG laser or carbide burs with or without the placement of MTA, and evaluated the presence of microcracks and gaps at the interface of GP/MTA and the canal walls. Ninety single-rooted teeth were instrumented, obturated with GP and AH-Plus sealer, and divided into 3 experimental groups: (I root-end resections were performed with the laser and G6 tips (parameters: 4.5 w, 30 pps, 20% water and 50% air; (II Lindeman burs were used, without the placement of MTA; (III the burs were used followed by root-end fillings with MTA, and one control (IV of five unobturated roots resected with the burs. The samples were prepared for microleakage (=20 and SEM (=10 analysis. They were immersed in 1% methylene blue, decalcified, cleared, and evaluated for dye penetration (mm2 with the ImageJ software. Epoxy-resin replicas of the root-ends were analyzed by SEM for gaps (m2 and microcracks. Microleakage results were 0.518±1.059, 0.172±0.223, and 0.158±0.253, for the laser (I, no root-end filling (II, and MTA (III samples, respectively, (ANOVA =.02. The laser (7831.7±2329.2 and no root-end filling (7137.3±1400.7 samples presented gaps. Whereas, none was found in the MTA (ANOVA =.002. Microcracks were not observed. The MTA group demonstrated statistically less leakage and better adaptation to the canal walls when compared to the other groups. There was no correlation between the size of the gaps and the degree of microleakage.

  2. Morphology of resin-dentin interfaces after Er,Cr:YSGG laser and acid etching preparation and application of different bonding systems.

    Beer, Franziska; Buchmair, Alfred; Körpert, Wolfram; Marvastian, Leila; Wernisch, Johann; Moritz, Andreas


    The goal of this study was to show the modifications in the ultrastructure of the dentin surface morphology following different surface treatments. The stability of the adhesive compound with dentin after laser preparation compared with conventional preparation using different bonding agents was evaluated. An Er,Cr:YSGG laser and 36% phosphoric acid in combination with various bonding systems were used. A total of 100 caries-free human third molars were used in this study. Immediately after surgical removal teeth were cut using a band saw and 1-mm thick dentin slices were created starting at a distance of 4 mm from the cusp plane to ensure complete removal of the enamel. The discs were polished with silicon carbide paper into rectangular shapes to a size of 6 × 4 mm (±0,2 mm).The discs as well as the remaining teeth stumps were stored in 0.9% NaCl at room temperature. The specimens were divided into three main groups (group I laser group, group II etch group, group III laser and etch group) and each group was subdivided into three subgroups which were allocated to the different bonding systems (subgroup A Excite, subgroup B Scotchbond, subgroup C Syntac). Each disc and the corresponding tooth stump were treated in the same way. After preparation the bonding composite material was applied according to the manufacturers' guidelines in a hollow tube of 2 mm diameter to the disc as well as to the corresponding tooth stump. Shear bond strength testing and environmental scanning electron microscopy were used to assess the morphology and stability of the resin-dentin interface. The self-etching bonding system showed the highest and the most constant shear values in all three main groups, thus enabling etching with phosphoric acid after laser preparation to be avoided. Thus we conclude that laser preparation creates a surface texture that allows prediction of the quality of the restoration without the risk of negative influences during the following treatment steps. This

  3. Evaluation of Er,Cr:YSGG Laser Effect on Microshear Bond Strength of a Self-Adhesive Flowable Composite in the Dentin of Permanent Molar: An In Vitro Study.

    Moslemi, Masoumeh; Fotouhi Ardakani, Faezeh; Javadi, Fatemeh; Khalili Sadrabad, Zahra; Shadkar, Zahra; Shadkar, Mohammad Saeid


    Aim and Background. Recently, new restorative materials such as self-adhesive flowable composites, because of their simple use and no need to bonding and etching, are considered important, particularly in pediatric dentistry. The aim of this study is to evaluate the effect of Er,Cr:YSGG laser on microshear bond strength of self-adhesive flowable composite on permanent teeth dentin in vitro. Material and Methods. In this experimental study, 40 dentin sections were prepared from healthy third molars and divided into two groups according to their surface preparation by Er,Cr:YSGG laser or without laser, only with silicon carbide paper. In each group, two groups of 10 teeth were treated with self-adhesive flowable composite (Dyad) and conventional flowable composite (acid etch and bonding). Samples were stored in normal saline and after 48 hours their bond strength was measured. The failure mode of samples was observed on stereomicroscope. In order to analyse the results, the one way ANOVA and Tukey's test for multiple comparisons were used. Result. The maximum bond strength was related to conventional flowable composite with laser preparation group (24/21 Mpa). The lowest one was seen in Dyad composite without laser emitting (9/89 Mpa). The statistical difference between this two groups was significant (P value = 0/0038). The microshear bond strength differences between Dyad composite groups with laser preparation (mean = 16/427 ± 1/79) and without laser preparation (mean = 12/85 ± 1/90) were statistically significant too (P value = 0/01). Conclusion. Self-adhesive flowable composite has lower microshear bond strength than conventional flowable composite. Moreover, the laser irradiation as a surface treatment can improve this bond strength.

  4. Evaluation of Er,Cr:YSGG Laser Effect on Microshear Bond Strength of a Self-Adhesive Flowable Composite in the Dentin of Permanent Molar: An In Vitro Study

    Masoumeh Moslemi


    Full Text Available Aim and Background. Recently, new restorative materials such as self-adhesive flowable composites, because of their simple use and no need to bonding and etching, are considered important, particularly in pediatric dentistry. The aim of this study is to evaluate the effect of Er,Cr:YSGG laser on microshear bond strength of self-adhesive flowable composite on permanent teeth dentin in vitro. Material and Methods. In this experimental study, 40 dentin sections were prepared from healthy third molars and divided into two groups according to their surface preparation by Er,Cr:YSGG laser or without laser, only with silicon carbide paper. In each group, two groups of 10 teeth were treated with self-adhesive flowable composite (Dyad and conventional flowable composite (acid etch and bonding. Samples were stored in normal saline and after 48 hours their bond strength was measured. The failure mode of samples was observed on stereomicroscope. In order to analyse the results, the one way ANOVA and Tukey’s test for multiple comparisons were used. Result. The maximum bond strength was related to conventional flowable composite with laser preparation group (24/21 Mpa. The lowest one was seen in Dyad composite without laser emitting (9/89 Mpa. The statistical difference between this two groups was significant (P value = 0/0038. The microshear bond strength differences between Dyad composite groups with laser preparation (mean = 16/427±1/79 and without laser preparation (mean = 12/85±1/90 were statistically significant too (P value = 0/01. Conclusion. Self-adhesive flowable composite has lower microshear bond strength than conventional flowable composite. Moreover, the laser irradiation as a surface treatment can improve this bond strength.

  5. Intrapupal temperature variation during Er,Cr: YSGG enamel irradiation on carries prevention

    Patrícia Moreira de Freitas


    Full Text Available Studies have shown the cariostatic effect of Er,Cr:YSGG (2.78 mm laser irradiation on human enamel and have suggested its use on caries prevention. However there are still no reports on the intrapulpal temperature increase during enamel irradiation using parameters for caries prevention. The aim of this in vitro study was to evaluate the temperature variation in the pulp chamber during human enamel irradiation with Er,Cr:YSGG laser at different energy densities. Fifteen enamel blocks obtained from third molars (3 x 3 x 3 mm were randomly assigned to 3 groups (n=5: G1 - Er,Cr:YSGG laser 0.25 W, 20 Hz, 2.84 J/cm², G2 - Er,Cr:YSGG laser 0.50 W, 20 Hz, 5.68 J/cm², G3 - Er,Cr:YSGG laser 0.75 W, 20 Hz, 8.52 J/cm². During enamel irradiation, two thermocouples were fixed in the inner surface of the specimens and a thermal conducting paste was used. One-way ANOVA did not show statistically significant difference among the experimental groups (a=0.05. There was intrapulpal temperature variation <0.1ºC for all irradiation parameters. In conclusion, under the tested conditions, the use of Er,Cr:YSGG laser with parameters set for caries prevention lead to an acceptable temperature increase in the pulp chamber.

  6. Evaluation of the Effects of Er,Cr:YSGG Laser, Ultrasonic Scaler and Curette on Root Surface Profile Using Surface Analyser and Scanning Electron Microscope: An In Vitro Study.

    Arora, Shipra; Lamba, Arundeep Kaur; Faraz, Farrukh; Tandon, Shruti; Ahad, Abdul


    Introduction: The periodontal therapy is primarily targeted at removal of dental plaque and plaque retentive factors. Although the thorough removal of adherent plaque, calculus and infected root cementum is desirable, it is not always achieved by conventional modalities. To accomplish more efficient results several alternative devices have been used. Lasers are one of the most promising modalities for nonsurgical periodontal treatment as they can achieve excellent tissue ablation with strong bactericidal and detoxification effects. Methods: Thirty freshly extracted premolars were selected and decoronated. The mesial surface of each root was divided vertically into four approximately equal parts. These were distributed into four group based on the root surface treatment. Part A (n = 30) was taken as control and no instrumentation was performed. Part B (n = 30) was irradiated by Erbium, Chromium doped Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser. Part C (n = 30) was treated by piezoelectric ultrasonic scaler. Part D (n = 30) was treated by Gracey curette. The surface roughness was quantitatively analyzed by profilometer using roughness average (Ra) value, while presence of smear layer, cracks, craters and melting of surface were analyzed using scanning electron microscope (SEM). The means across the groups were statistically compared with control using Dunnett test. Results: Among the test groups, Er,Cr:YSGG laser group showed maximum surface roughness (mean Ra value of 4.14 μm) as compared to ultrasonic scaler (1.727 μm) and curette group (1.22 μm). However, surface with smear layer were found to be maximum (50%) in curette treated samples and minimum (20%) in laser treated ones. Maximum cracks (83.34%) were produced by ultrasonic scaler, and minimum (43.33%) by curettes. Crater formation was maximum (50%) in laser treated samples and minimum (3.33%) in curette treated ones. 63.33% samples treated by laser demonstrated melting of root surface, followed by

  7. Er,Cr:YSGG 激光对老年人非龋性硬化牙本质粘结强度的影响%Effect of Er,Cr:YSGG laser on the Bonding strength of the elderly non-carious sclerotic dentin

    刘艳; 付强; 葛志华; 贾兴亚


    AIM:To evaluate the effect of Er , Cr:YSGG laser preparation on the bonding properties be-tween composite resin and the the sclerotic dentin of elderly subjects .METHODS:40 extracted premolars with cervi-cal wedge-shaped defect and sclerotic dentin on the surface from 60~70 year-old people were randomly divided into 2 groups (n=20).In the experimental group Er,Cr:YSGG laser was used for cavity preparation , in the control group regular burs with high-speed turbines was used for cavity preparation .The cavies of all teeth were filled with composite resin Filtek Z350.15 samples in each group were cut into dumbbell-shaped specimens with a bonding area of 1 mm2 . The micro-tensile bond strength (MBS) was tested on Instron 5848 Micro Tester.Each tooth of the remaining 5 sam-ples in each groupe were divided into two parts along buccolingual directions parallel to the long axis of the tooth .The bonding interface was observed by SEM .RESULTS: The MBS ( MPa ) of experimental and control groups was (35.24 ±7.05)MPa and(27.56 ±4.79)MPa respectively(P<0.05).SEM observation showed that hybrid layer be-tween sclerotic dentin and composite resin was thinner in experimental group , resin tags, and crystallizing column with-in dentinal tubules connected together tightly .CONCLUSION:Er,Cr:YSGG laser preparation can improve the bond strength between elderly non-carious sclerotic dentin and composite resin .%目的:评价Er,Cr:YSGG激光备洞对离体牙楔形缺损处非龋性硬化牙本质与复合树脂间粘结性能的影响。方法:选取40个颊侧颈部有楔形缺损的老年人(60~70岁)前磨牙,随机分2组(n=20),分别用Er,Cr:YSGG激光(实验组)和高速涡轮牙钻(对照组)备洞后,用复合树脂Filtek Z350进行充填;然后每组各取15个样本制备成粘结面积约为1 mm ×1 mm的哑铃形片状试件,用Instron 5848微力试验机测定其微拉伸粘结强度( MBS);每组剩余的另5个样本分别

  8. Study on the microleakage between the composite resin and cavity wall after Er,Cr∶YSGG laser preparation%复合树脂与Er,Cr∶YSGG激光制备的窝洞壁间微渗漏评价

    贾兴亚; 王凤艳; 刘策


    目的:研究复合树脂与Er,Cr∶YSGG(掺铒铬钇钪镓石榴石)激光制备的窝洞壁间微渗漏.方法:将30颗离体前磨牙随机分为3组(n=10),制备Ⅴ类洞.第1组为激光预备加37%磷酸处理组,第2组为激光预备加FL-BOND处理组,第3组为激光预备加17%EDTA处理组.经冷热循环染色后,采用染料渗入法和扫描电镜方法观察充填体微渗漏情况,采用SPSS11.0软件包对数据进行统计学处理.结果:骀壁处染料渗入结果显示,第2组的染料渗入评分最小,与其余2组有显著差异(P<0.05),第1组与第3组无显著差异.扫描电镜观察显示,第2组与第3组的边缘微缝隙宽度有显著差异(P<0.05),其余各组间无显著差异,此结果与染料渗入法的结果不完全一致.龈壁处,3组染料渗入评分及充填体边缘微缝隙宽度均无显著差异,仅第2组(牙合)壁与龈壁的染料渗入评分及边缘微缝隙宽度有显著差异(P<0.05).结论:自酸蚀黏结剂可有效减少复合树脂与Er,Cr∶YSGG激光制备的Ⅴ类洞(牙合)壁间微渗漏;在全酸蚀黏结剂及应用EDTA处理剂的条件下,复合树脂与Er,Cr∶YSGG激光制备的窝洞壁间微渗漏无差异.%PURPOSE: To evaluate microleakage between the composite resin and cavity wall after Er,Cr:YSGG laser preparation. METHODS: Class V cavities were prepared in 30 sound extracted human premolars. The teeth were randomly divided into 3 groups (n=10).Group 1 was treated with Er,Cr:YSGG+37%phosphoric acid, group 2 was treated with Er,Cr:YSGG+FL-BOND and group 3 was treated with Er,Cr:YSGG+17%EDTA.Then the specimens were subjected to thermocycling and staining. The marginal microleakage was assessed by dye penetration method and scanning electronic microscope (SEM). The data was analyzed with SPSS11.0 software package. RESULTS: In occlusal margins,microleakage in group 2 was significantly lower than that in the other two laser groups (P<0.05).No significant difference was found

  9. The effect of Er, Cr:YSGG laser irradiation on the microleakage of composite resin restorations%Er,Cr:YSGG激光制洞对光固化复合树脂边缘微渗漏的影响

    贾兴亚; 王凤艳; 刘策


    目的:比较在自酸蚀黏结剂的应用条件下,Er,Cr:YSGG激光制备与传统牙钻制备离体牙牙颈部洞对光固化复合树脂边缘微渗漏的影响.方法:将20个因正畸拔除的新鲜完整无龋损、无隐裂、无充填物的前磨牙随机分为两组(n=10),分别使用牙钻和Er,Cr:YSGG激光制备牙颈部洞.窝洞制备后均匀涂覆FL-BOND,用TPH复合树脂进行分层充填,打磨、抛光,37℃生理盐水中存放7d后,进行500次温度循环实验(5±2)℃—(55±2)℃.将上述所有样本置0.5%碱性品红液中室温浸泡24h后,沿牙体长轴通过修复体正中纵行剖开,采用染料渗入法和扫描电镜方法观察充填体微渗漏情况,运用SPSS 11.0软件包进行统计学处理.结果:牙钻制备组与激光组相比,无论(牙合)壁还是龈壁的染料渗入评分和边缘微缝隙宽度均无显著性差异(P>0.05).结论:在自酸蚀黏结剂的应用条件下,Er,Cr:YSGG激光制洞不能显著减少光固化复合树脂边缘微渗漏的发生.%AIM: To compare the microleakage of Class V resin composite restorations following Er,Cr:YS-GG laser and high -speed rotary preparation using a self-etch adhesive system. METHODS; Twenty orthodontically extracted human premolars were randomly divided into two groups (n = 10) and Class V cavities were prepared in the teeth with Er,Cr:YSGG laser or bur. The cavities were then coated with FL-BOND adhesive system and TPH resin composite was used for restoration. After finishing and polishing, the teeth were stored for seven days in distilled water at 37 t before they were subjected to thermocycling for 500 times (5 ±2℃ -55 ±2℃ ). Then they were stained in asolution of 0.5% basic fuchsion at room temperature and sectioned in a buccolingual plane through the centre of the restorations. The marginal microleakage was observed by dye penetration method and SEM. The data was analyzed with SPSS11.0 software package. RESULTS: Microleakage test and the space

  10. Nanostructured synthetic hydroxyapatite and dental enamel heated and irradiated by ER,CR:YSGG: characterized by FTIR and XRD; Hidroxiapatita sintetica nanoestruturada e esmalte dental aquecidos e irradiados por laser de Er,Cr:YSGG: caracterizacao por FTIR e por DRX

    Rabelo Neto, Jose da Silva


    The study evaluate the physical changes and/or chemical that occurs in synthetic hydroxyapatite (HAP) and in enamel under action of thermal heating in oven or laser irradiation of Er,Cr:YSGG that may cause changes in its structure to make them more resistant to demineralization aiming the formation of dental caries. The synthetic HAP was produced by reaction of solutions of Ca(NO{sub 3}) and (NH{sub 4}){sub 2}HPO{sub 4} with controlled temperature and pH. The enamel powder was collected from the bovine teeth. Samples of powder enamel and synthetic HAP were subjected to thermal heating in oven at temperatures of 200 deg C, 400 deg C, 600 deg C, 800 deg C and 1000 deg C. For the laser irradiation of materials, were made with 5,79 J/cm{sup 2} of irradiation, 7,65 J/cm{sup 2}, 10,55 J/cm{sup 2} and 13,84 J/cm{sup 2} for synthetic HAP and 7,53 J/cm{sup 2}, 10,95 J/cm{sup 2}, and 13,74 J/cm{sup 2} for the enamel. The samples were evaluated by X-ray diffraction (XRD) for analysis of crystallographic phases and analysis by the Rietveld method, to determine their respective proportions in the material, as well as results of changes of the lattice unit cell parameters (axis-a, axis-c and volume), crystallites sizes and the occupation rate of sites of Ca and P atoms. The samples were analyzed by Fourier transform infrared spectroscopy (FTIR), which should compositional changes due to treatment related to carbonate, phosphate, adsorbed water and hydroxyl radicals content. The infrared was used to measure the surface temperature generated by the laser beam in the solid samples of enamel. Besides the major hydroxyapatite crystallographic phases, there was formations of octa calcium phosphate (OCP) and phase {beta} of tricalcium phosphate ({beta}-TCP ) in enamel heated at 800 deg C. There was reduction of the axis-a, volume and size of crystallites to the temperatures between 400 degree C and 600 deg C and also on laser irradiated samples. Above the temperature of 600 degree C it

  11. Expression of HSP70 in rabbit dental pulp after cavity preparation with Er,Cr:YSGG laser%Er,Cr:YSGG激光备洞对兔牙髓组织热休克蛋白70表达的影响

    杨超; 贾兴亚; 安欣; 王抒智; 钟鸣


    目的 观察Er,Cr:YSGG激光用于牙体窝洞制备后兔牙髓的形态学变化及热休克蛋白70 (heat shock protein70 HSP70)的表达情况.方法 用Er,Cr:YSGG激光在家兔前牙制备V类洞并常规充填,普通高速牙钻备洞作对照,分别于术后4h、24h处死实验动物,组织切片经HE染色及免疫组化染色,镜下观察.结果 Er,Cr:YSGG激光备洞后牙髓轻到中度炎症反应,与牙钻对照组无明显差异.备洞后24h,激光组成牙本质细胞HSP70中到强阳性表达,成纤维细胞、血管内皮细胞中度阳性表达.牙钻组成牙本质细胞及相邻成纤维细胞强阳性表达,血管内皮细胞强阳性表达,对照组HSP70表达高于Er,Cr:YSGG激光实验组,差别有统计学意义(P<0.05).结论 Er,Cr:YSGG激光备洞对牙髓刺激小,有很好的临床使用价值.%Objective To observe the dental pulpal morphological changes and the expression of HSP70 to cavity preparation in rabbit incisors by the Er,Cr:YSGG laser. Methods A total of thirtyt-wo incisors of eight healthy rabbits were divided into two groups: Er,Cr:YSGG laser and conventional bur group.after the cavities preparation by the laser and the conventional bur in rabbit incisors, the cavities, were filled by normal way .The teeth were extracted 4 and 24 hours after operation respectively, after HE and immunohistochemical staining, the tissue sections were observed by microscopy. Results The histological examination showed that there was no appreciable difference in the manner in which dental pulp tissue responds to cavity preparation with either Er,Cr:YSGG laser or a conventional bur. 24h after the operation, the Er,Cr:YSGG laser group have a moderate to strong expression of HSP70 in Odontoblasts,and moderate expression in Fibroblast and endothelial cells.the expression of HSP70 in the control group was higher than that in the Er, Cr:YSGG laser group (P<0.05). Conclusion Cavity preparation by Er,Cr:YSGG laser causes no noticeable pulpal damage

  12. Comparison of the effect of Er, Cr-YSGG laser and ultrasonic retrograde root-end cavity preparation on the integrity of root apices.

    Rahimi, Saeed; Yavari, Hamid R; Shahi, Shahriar; Zand, Vahid; Shakoui, Sahar; Reyhani, Mohammad F; Pirzadeh, Ahmad


    The aim of this study was to compare the effect of Waterlase laser and ultrasonic root end cavity preparation on the integrity of root end in extracted human teeth. The canals of 60 extracted maxillary central incisors were cleaned, shaped, obturated and 3 mm of the root end was resected and examined for the presence of any cracks. Class I root-end cavities were then prepared using an ultrasonic unit or Waterlase laser. In the ultrasonic group, KIS 2D tip and medium intensity and in the laser group, 600 mum laser tips and an output power setting of 4 W with 55% water and 65% air were used to prepare the cavity which was studied for the presence of any cracks or chippings. One crack was found in the ultrasonic group, while no cracks were observed in the laser group. There was no significant difference between the two groups (P > 0.05). As for the chipping effect, seven cases (23%) had chipping after cavity preparation in the ultrasonic group but no chipping was found in the specimens of the laser group and the difference was statistically significant (P < 0.05). According to the results of this in vitro study, laser preserves the integrity of root-end cavities better than ultrasonic devices from the standpoint of producing chipping.

  13. The use of laser technology (Er;Cr:YSGG) and stereolithography to aid in the placement of a subperiosteal implant: case study.

    Kusek, Edward R


    The use of laser technology has helped this clinician to provide treatment with less postoperative pain and increased healing. The subperiosteal implant is a modality that has been used for several decades, although its popularity has declined in favor of endosseous dental implants. In some instances, however, it remains the treatment of choice, specifically in the atrophic mandible (where placement of endosseous implants is not possible) or when placement would increase the chances of jaw fracture. This article reports the case of a patient rehabilitated using a simplified surgical protocol involving laser surgery and stereolithography.

  14. The effect of Er,Cr:YSGG laser irradiation different age patients on the microleakage of Class V resin composite restorations%Er,Cr∶YSGG激光预备不同年龄患者V类洞对复合树脂微渗漏的影响

    王抒智; 贾兴亚; 杨超; 安欣; 杜健男; 李阳


    目的 研究比较Er,Cr∶YSGG激光与传统牙钻均分别预备老年及青年离体磨牙V类洞对复合树脂充填微渗漏的影响.方法 于2012年5月~9月,在中国医科大学口腔医院,将10颗老年及10颗青年因牙周病或阻生拔出的无龋坏、无充填物、无隐裂的磨牙,按预备方式不同,平均分为四组:第一组,老年高速;第二组,老年激光;第三组,青年高速;第四组 青年激光,每组5颗牙.经200次冷热循环染色后,将上述所有样本置于0.5%碱性品红溶液中浸泡24小时后,沿牙体长轴通过充填体正中纵行割开,在体视显微镜下根据染料渗入等级评分(0~3)及扫描电镜方法观察充填体微渗漏情况.结果 (牙合)壁和龈壁处,染料渗入结果显示,老年组和青年组染料渗入评分差异有统计学意义(P<0.05),老年组大于青年组;激光组和牙钻组差异无统计学意义(P>0.05).充填体边缘微缝隙宽度的结果显示,4组充填体边缘微缝隙宽度差异存在统计学意义(P<0.05),其中老年牙钻组的边缘微裂隙最大,青年激光组的边缘微裂隙最小.结论 在自酸蚀粘结剂的应用条件下,Er,Cr∶YSGG激光预备处理V类洞不能显著减少光固化复合树脂边缘微渗漏的发生;老年磨牙组与青年磨牙组相比较,无论是Er,Cr∶YSGG激光还是牙钻预备光固化复合树脂充填后,微渗漏评分及边缘微缝隙均大于青年磨牙组.%Objective The purpose of this study was to compare and study microleakage of Class V composite restorations following high-speed rotary and Er,Cr:YSGG laser preparation old and young molars. Methods From May 2012 to September, in the Stomatological Hospital of China Medical University ,caries-free vital ten old and ten young molars freshly extracted for periodontic or- orthodontic reasons were used in this study. Prepare different ways are divided into four groups:The first group old high-speed ;The second group old Er,Cr:YSGG

  15. Erbium: YAG Laser Incision of Urethral Strictures for Treatment of Urinary Incontinence After Prostate Cancer Surgery


    first report of a small, flexible optical fibre could prove beneficial in germanium and sapphire fibre optic transmission of medical applications...strated increased fibre optic transmission of Q-switched Model EPM 1000, Portland, Ore., USA) and the tem- erbium:YSGG laser radiation using germanium...running and Q-switched (b) .Er:YSGG laser radiation through sapphire and germa- nium oxide optical fibres is shown in Fig. 2. Fibre optic Er:YSGG

  16. Thermal effects on zirconia substrate after Er,Cr:YSGG irradiation

    Alessandra Cassoni

    Full Text Available OBJECTIVE: The objective of the present study was to investigate the thermal effects of Er,Cr:YSGG laser irradiation (1.5W/20Hz on yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP. MATERIAL AND METHOD: Fifteen disks of Y-TZP (AS Technology TitaniumFIX, São José dos Campos, Brazil with 5 mm diameter and 3 mm high standardized with CAD-CAM were used. The Y-TZP disks were randomized in three groups (n=5: Y-TZP-G1 = control (no laser treatment; Y-TZP-G2 = Y-TZP + Er,Cr:YSGG laser (air-water cooling proportion 80%/25%; Y-TZP-G3 = Y-TZP + Er,Cr:YSGG laser (air-water cooling proportion 80%/0%. A thermopar (SmartMether, Novus, Porto Alegre, RS, Brazil was attached to a digital thermometer (SmartMether, Novus, Porto Alegre, RS, Brazil fixed to the opposite irradiated surface. The temperature gradients (ΔT were calculated (ΔT = Final Temperature - Initial Temperature for each group. Values were statistically analyzed by one-way ANOVA at the 95% confidence level and compared by Tukey post-hoc test (α=0.05 for each material. One sample of each group was analyzed by confocal white light microscopy. RESULT: The ANOVA test showed significant differences for the factor "laser" (p<.001. The temperature gradients (ΔT value showed the following results: Y-TZP-G1 = 0 ºC; Y-TZP-G2 = -1.4 ºC and Y-TZP-G3 = 21.4 ºC. The ΔT values (ºC of the non-refrigerated group were higher than the refrigerated group. The roughness value (Ra ranged from 4.50 to -33.65 µm. CONCLUSION: The water refrigeration for Er,Cr:YSGG irradiation is essential to avoid thermal increase in the Y-TZP.

  17. Laser terapia no controle da mucosite oral: um estudo de metanálise

    André Luiz Peixoto Figueiredo


    Full Text Available OBJETIVO: Realizar uma metanálise da eficácia da laser terapia (LT na prevenção damucosite oral (MO em pacientes submetidos à oncoterapia. MÉTODOS: Foi realizada uma busca nas bases de dados MEDLINE, LILACS e Cochrane, utilizando as palavras-chave "laser therapy" e "oral mucositis". Os estudos de caso-controle incluídos foram submetidos à análise do odds ratio (OR, cujo ponto de corte para a estatística foi MO grau > 3. Os cálculos foram realizados com o programa BioEstat 5.0, utilizando a análise estatística de Efeito Aleatório de DerSimonian-Laird. RESULTADOS: Doze estudos foram incluídos na revisão sistemática. A metanálise de sete deles evidenciou que a LT em pacientes submetidos à oncoterapia é aproximadamente nove vezes mais eficaz na prevenção de MO grau > 3 do que empacientes sem o tratamento com laser (OR: 9,5281; intervalo de confiança de 95% 1,447-52,0354, p = 0,0093. CONCLUSÃO: Esses dados demonstraram efeito profilático significativo de MOgrau > 3 nos pacientes submetidos à LT. Estudos com maior tamanho amostral são necessários para melhor avaliação do efeito profilático de MO grau > 3 por LT.

  18. 掺铒铬钇钪镓石榴石激光去腐备洞技术的临床评价%Clinical evaluation of Er,Cr:YSGG laser for caries removal and cavity preparation

    郭标新; 王君香; 王欢


    目的:应用掺铒铬钇钪镓石榴石(Er,Cr:YSGG)激光去腐备洞技术在减轻疼痛、充填后远期效果及工作效率等方面的临床评价.方法:选择口内同时存在2个龋坏程度相似的同名牙病例30例,自身对照方法,分别采用Er,Cr:YSGG激光(实验组)和传统涡轮牙钻(对照组)去腐备洞.使用Wong-Baker面部表情量表对治疗过程中的疼痛程度进行评估,调查每个病例对两种方法的接受程度,记录去腐备洞时间,并分别在治疗后6个月,12个月复查充填体情况.结果:和传统的涡轮牙钻去腐备洞比较,Er,Cr:YSGG激光可明显减轻备洞过程中的疼痛,差异有显著性(P <0.01);80 %的患者更愿意选择Er,Cr:YSGG激光技术进行治疗;Er,Cr:YSGG激光和涡轮牙钻去腐备洞的平均时间分别是504 s和390 s ;治疗后6个月,12个月复查,实验组和对照组差异无显著性.结论:Er,Cr:YSGG激光去腐备洞技术可显著减轻治疗过程中的疼痛和不适,在切割牙体硬组织方面具有独特的优点.

  19. Er,Cr∶ YSGG激光备洞对老年人非龋性硬化牙本质微拉伸粘接强度的影响%Influence of Er, Cr∶YSGG Laser on the Microtensile Bond Strength of the Non-Carious Sclerotic Dentin of the Elderly

    刘艳; 王洋; 贾兴亚


    Objective To evaluate the influence of Er, Cr: YSGG laser on the microtensile bond strength of the non-carious sclerotic dentin of the elderly, and compare the influence of two different filling materials on the bond strength. Methods Forty elderly premolars having wedge-shaped defects and typical sclerotic dentin on the surface were randomly divided into the experimental group and control group. The premolars in the experimental group were processed with Er, Cr: YSGG laser, and those in the control group with high-speed dental turbine handpiece. Each group was further divided into two subgroups, having composite resin or glass ionomer cement as filling agents. The teeth were stored in distilled water for 24 hours at 371C and then cut into dumbbell - shaped specimens approximating 1 mm in thickness. The microtensile bond strength was determined with Instron 5 848 Micro Tester. Then the morphological change of dentin surface was observed with SEM. Results n the experimental group, the microtensile bond strength stood at (35. 24 7.05) Mpa and (17.71 5. 74) Mpa respectively for the composite resin subgroup and glass ionomer cement subgroup. In the control group, it was (27. 56 4. 79) Mpa and (11.47 5. 12) Mpa respectively for the composite resin subgroup and glass ionomer cement subgroup. The difference of microtensile bond strength between the experimental group and control group was statistically significant (P < 0.05 ). Within either group, the difference of microtensile bond strength between the composite resin subgroup and glass ionomer cement subgroup was statistically significant (P < 0.05). Conclusions The elderly non - carious sclerotic dentin processed with Er, Cr: YSGG laser has higher bonding strength than that with high - speed dental turbine handpiece. Composite resin is greater than glass ionomer in bonding strength.%目的 评价Er,Cr∶ YSGG激光备洞对硬化牙本质微拉伸粘接强度的影响,并比较其对两种不同充填材

  20. Comparative evaluation of surface topography of tooth prepared using erbium, chromium: Yttrium, scandium, gallium, garnet laser and bur and its clinical implications

    Mahesh Verma


    Conclusions: Er, Cr: YSGG laser can be used for preparing tooth and bond strength value achieved by laser preparation alone without surface treatment procedure lies in the range of clinical acceptability.

  1. Laser pediatric crowns performed without anesthesia: a contemporary technique.

    Jacboson, B; Berger, J; Kravitz, R; Patel, P


    Extensive caries resulting in the need for a stainless steel crown in primary teeth may now be prepared with the use of the WaterlaseTM YSGG Laser, (Biolase) hard and soft-tissue laser. The use of the laser eliminates the need for local anesthesia, thereby providing optimal patient comfort and compliance.


    Patricia Bahls de Almeida Farhat


    Este estudo determinou o efeito do laser terapêutico vermelho e infravermelho, presente ou não nos equipamentos híbridos LED/Laser na ativação do gel e no controle da sensibilidade dentária, decorrente do clareamento dental realizado em consultório, ativados por luz LED. Um ensaio clínico andomizado, cego, de boca dividida foi realizado em quatro grupos (n=16): Grupo LED (GL), Grupo LED/Laser infravermelho de baixa intensidade (GLL), Grupo LED + Laser terapêutico infravermelho (GLIV) e Gru...

  3. Estudos de espelhos dielétricos multicamadas para laser de Nd-YAG.

    Luiz Carlos Magalhães Lavras


    Foram realizados estudos sobre as propriedades ópticas, através das medidas de índice de refração e coeficiente de absorção, dos materiais pentóxido de tântalo ( Ta2O5 ) e óxido de zircônio ( ZrO2 ), na forma de filmes finos, antes e após tratamento térmico. Os filmes foram produzidos utilizando a técnica de evaporação por feixe de elétrons, com a pressão residual de oxigênio de 1,0.10-4 torr, e a temperatura de 135C, em substrato de vidro BK-7. Foram utilizadas duas técnicas de caracterizaçã...

  4. Shear bond strength of bonding to enamel with different laser irradiation distances.

    Başaran, Güvenç; Hamamcı, Nihal; Akkurt, Atılım


    The aim of this study was to investigate the shear bond strength of bonding to enamel following laser etching with the Er:YAG or Er,Cr:YSGG laser using different irradiation distances. Of 99 extracted human premolar teeth, 90 were divided equally into nine groups. In the control group (group A) the teeth were etched with 38% phosphoric acid. In the laser groups (groups B-I) the enamel surface of the teeth was laser-irradiated, groups B-E with the Er:YAG laser and groups F-I with the Er,Cr:YSGG laser at distances of 1, 2, 4 and 6 mm, respectively. The shear bond strengths were tested using a universal testing machine. The shear bond strengths associated with the Er:YAG laser at 4 and 6 mm and the Er,Cr:YSGG laser at 2, 4 and 6 mm were significantly less than the strengths obtained with the other irradiation distances (penamel in the same manner (p>0.05). This finding was confirmed by scanning electron microscopy examination. Irradiation distance did influence the strength of adhesion to enamel. The mean shear bond strengths and enamel surface etching obtained with the Er:YAG laser at 1 and 2 mm and the Er,Cr:YSGG laser at 1 mm were comparable to that obtained with acid etching.

  5. Effect of different laser surface treatment on microshear bond strength between zirconia ceramic and resin cement.

    Akhavan Zanjani, Vagharaldin; Ahmadi, Hadi; Nateghifard, Afshin; Ghasemi, Amir; Torabzadeh, Hassan; Abdoh Tabrizi, Maryam; Alikhani, Farnaz; Razi, Reza; Nateghifard, Ardalan


    The purpose of this study was to evaluate the effect of sandblasting, carbon dioxide (CO₂), and erbium,chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) lasers on the microshear bond strength of zirconia to resin cement. Sixty-one sintered yttria stabilized tetragonal zirconia blocks (10 × 5 × 2 mm) were prepared and divided into four experimental groups (n = 15); one sample was retained as a control. The samples were treated by aluminium oxide air abrasion, CO₂4W, Er,Cr:YSGG 3W, and Er,Cr:YSGG 2W, respectively. One sample from each group and the control sample were analyzed by scanning electron microscope. Panavia F2.0 resin microcylinders were prepared and placed on treated surfaces, light cured, and incubated for 48 h. Microshear bond strength testing was done by a microtensile tester machine, and the type of bond failures were determined by stereomicroscope. Data were analyzed by one-way anova and Tukey's test at a significance level of P laser showed significantly higher bond strength than Er,Cr:YSGG 2W (P laser-treated surfaces, the roughness was much less than the air abrasion-treated surfaces, and the mode of failure was almost pure adhesive. Air abrasion has a greater effect than CO₂and Er,Cr:YSGG lasers in the treatment of zirconia ceramic surfaces to enhance the bonding strength of resin cement to zirconia. CO₂laser at 4W and Er,Cr:YSGG laser at only 3-W output power can be regarded as surface treatment options for roughening the zirconia surface to establish better bond strength with resin cements. © 2014 Wiley Publishing Asia Pty Ltd.

  6. Effect of the lasers used in periodontal therapy on the surfaces of restorative materials.

    Hatipoğlu, Mükerrem; Barutcigil, Çağatay; Harorlı, Osman Tolga; Ulug, Bülent


    The present study aimed to reveal potential damage of the lasers, which are used as an alternative to manual instruments in periodontal therapy, might cause to the surface of restorative materials. Four different restorative materials were used: a glass-ionomer cement (GIC), a flowable composite (FC), a universal composite (UC) and an amalgam. Ten cylindrical samples (8 mm × 2 mm) were prepared for each restorative material. Two laser systems were used in subgingival curettage mode; an 940 nm diode laser (Epic Biolase, Irvine, CA) and an Er,Cr:YSGG laser (Waterlase iPlus, Biolase, Irvine, CA). After laser irradiation, roughness of the sample surfaces was measured using a profilometer. Additionally, atomic force microscopy (AFM) and scanning electron microscopy (SEM) analyses were performed to evaluate the morphology and surface deformations of the restorative materials and surfaces. The laser irradiation did not affect the surface roughness of any restorative materials relative to that of the control group (p > 0.05) except for the Er,Cr:YSGG treatment on GIC (p surface roughness tests. Within the limitations of the present study, it was demonstrated that Er,Cr:YSGG and diode lasers, aside from the Er;Cr:YSGG treatment on GIC, caused no harmful surface effects on adjacent restorative materials. SCANNING 38:227-233, 2016. © 2015 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

  7. Estudo, desenvolvimento e obtenção de peças plasticas tridimensionais atraves da litografia termica, utilizando laser de CO2

    Mucio Leite de Barros


    Resumo: Este trabalho de tese apresenta uma nova técnica denominada litografia térmica 3D, destinada ao estudo e confecção de peças tridimensionais de plástico com geometria desejada, através da interação entre o laser de C02 (10,6pm) e resinas liquidas termosensiveis de alta viscosidade, do tipo epóxi e poliester insaturado. Nesta técnica é utilizada o laser de C02 com potência da ordem de 20 watt na confecção de peças (anéis), com resolução da ordem de 0,20 mm e 0,10 mm respectivamente para...

  8. Estudo da soldabilidade a laser e a TIG do titânio comercialmente puro grau 2 empregado em sistemas pneumáticos de aeronaves

    Sheila Medeiros de Carvalho


    O conjunto de tubos denominado sistema pneumático, tem a função de conduzir o ar quente pressurizado desde o motor até os pontos de utilização pelos sistemas ambientais da aeronave. A ocorrência de falhas em serviço de peças desse sistema soldadas pelo processo TIG (Tungsten Inert Gas), motivou o estudo da substituição desse processo pelo de soldagem a laser. Foi utilizado um laser a fibra de 2 kW de potência e tubos de titânio comercialmente puro grau 2, de 0,5 mm de espessura e 50 mm de diâ...

  9. Application of lasers in endodontics

    Ertl, Thomas P.; Benthin, Hartmut; Majaron, Boris; Mueller, Gerhard J.


    Root canal treatment is still a problem in dentistry. Very often the conventional treatment fails and several treatment sessions are necessary to save the tooth from root resection or extraction. Application of lasers may help in this situation. Bacteria reduction has been demonstrated both in vitro and clinically and is either based on laser induced thermal effects or by using an ultraviolet light source. Root canal cleansing is possible by Er:YAG/YSGG-Lasers, using the hydrodynamic motion of a fluid filled in the canals. However root canal shaping using lasers is still a problem. Via falsas and fiber breakage are points of research.

  10. Impact of codopant ions on 2.5-3.0 μm emission of Er3+:4I11/2→4I13/2 transition in Yb,Er,Eu:LaYSGG crystal

    Wang, Yan; Li, Jianfu; Zhu, Zhaojie; You, Zhenyu; Xu, Jinlong; Tu, Chaoyang


    The crystal of 1 at% Yb3+, 10 at% Er3+ and 0.1 at% Eu3+ triply doped La0.3Y2.7Sc2Ga3O12 (abbr. as Yb,Er,Eu:LaYSGG) was grown for the first time by using a Czochralski technique. Its absorption, near-infrared and mid-infrared fluorescence spectra, as well as the fluorescence decay curves of Er:4I13/2 and 4I11/2 levels were measured at room temperature. The spectroscopic properties including the absorption and emission cross-sections as well as the fluorescence lifetimes of the title crystal were revealed and compared with 10 at% Er3+:Y3Sc2Ga3O12 crystal. Spectral analyses show that the sensitization of Yb3+ ion leads to an enhanced 2.5-3.0 μm emission corresponding to Er3+:4I11/2→4I13/2 transition in the grown crystal, meanwhile, the depopulation of Eu3+ ion from Er3+ inhibits the self-termination effect successfully. The energy transfer mechanism was discussed; the energy transfer efficiencies of Yb3+→Er3+ (ET1) and Er3+→Eu3+ (ET2) were estimated to be 94.8% and 93.9%, respectively. The results indicates that Yb,Er,Eu:LaYSGG crystal is a good candidate for LD pumped mid-infrared laser.


    A. A. L. de Araujo Lima


    Full Text Available Através da determinação do potencial de membrana mitocondrial, o presente estudo relata os efeitos da irradiação laser sobre o estado energético do fígado cirrótico de ratos hepatectomizados. A cirrose hepática foi induzida por ligadura do ducto biliar comum. Os resultados revelaram melhora do status energético do fígado após irradiação.

  12. One Visit Providing Desirable Smile by Laser Application

    Fekrazad, Reza


    Introduction: Providing desirable smile is one of the main concerns in cosmetic dentistry. Hyperpigmentation is one of the esthetic concerns especially in gummy smile patients. Lasers with different wavelength are used for oral surgery including Carbon Dioxide Laser (CO2), Neodymium-Doped Yttrium Aluminium Garnet (Nd:YAG), Erbium family and diode laser. In this case, all esthetic procedures including gingival depigmentation, caries detection and removal were done by laser technology in one session. Case study: A 40- year-old male with a chief complaint of black gingiva in upper jaw was referred. The right side of maxillary was anesthetized and depigmentation was done by Erbium, Chromium doped Yttrium Scandium Gallium Garnet (Er-Cr: YSGG) laser. Due to scores obtained from Diagnodent which indicated caries in dentin, the cavities were prepared by Er-Cr:YSGG laser. The cavities were restored by composite resin. The patient was advised to keep oral hygiene instructions and use mouthwash. Results: The patient reported no pain after surgery and did not use any systemic antibiotic. After 4 weeks, complete healing was observed. Conclusion: Considering acceptable clinical outcome, Er-Cr: YSGG laser can be considered as an effective method for combination of soft and hard tissue treatment. PMID:25606339

  13. Testing relativity again, laser, laser, laser, laser

    Einstein, A.


    laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser,

  14. Comparative evaluation of microhardness and morphology of permanent tooth enamel surface after laser irradiation and fluoride treatment - An in vitro study.

    Kumar, Puneet; Goswami, Mridula; Dhillon, Jatinder Kaur; Rehman, Ferah; Thakkar, Deepti; Bharti, Kusum


    Background and aims: The aim of the study was to evaluate and compare the surface microhardness and surface morphology of permanent tooth enamel after Er,Cr:YSGG laser irradiation and Fluoride application. Materials and methods: One hundred and twenty premolars extracted for orthodontic purpose were used in the study and randomly divided into 6 groups. Group A was not subjected to any treatment. Group B was subjected to Er,Cr:YSGG laser irradiation. Group C was subjected to Er,Cr:YSGG laser irradiation followed by application of 2% NaF gel for 4 minutes. Group D was subjected to laser irradiation and 1.23% APF gel for 4 minutes. Group E was subjected to 2% NaF gel pretreatment technique followed by laser irradiation. Group F was subjected to 1.23% APF gel pretreatment technique followed by laser irradiation. All the test groups were subjected to microhardness testing and scanning electron microscope evaluation at 500 X and 1500 X. Results: All the treated groups showed an increase in microhardness value in comparison to the control group. The highest increase in microhardness was seen in Group F. Increase in microhardness values of Group B and Group D was not statistically significant as compared to Group A. Scanning Electron Micrographs showed few craters and fine porosities for Group A. These craters and porosities increased in size and often showed glass like appearance after laser irradiation. Conclusions: It can be suggested by means of present study that Er,Cr:YSGG laser irradiation alone or in combination with fluoride gel is an effective tool to provide resistance against the caries. Significantly higher resistance (p< 0.05) was seen when APF gel was used prior to Er,Cr:YSGG laser irradiation and this combination can act as an efficient tool for prevention against dental caries.

  15. Study of the mechanisms involved in the laser superficial hardening process of metallic alloys; Estudo dos mecanismos envolvidos no processo de endurecimento superficial a laser de ligas metalicas

    Silva, Edmara Marques Rodrigues da


    The laser superficial hardening process of a ferrous alloy (gray cast iron) and of an aluminum-silicon alloy was investigated in this work. These metallic alloys are used in the automobile industry for manufacturing cylinders and pistons, respectively. By application of individual pulses and single tracks, the involved mechanisms during the processing were studied. Variables such as energy density, power density, temporal width, beam diameter on the sample surface, atmosphere of the processing region, overlapping and scanning velocity. The hardened surface was characterized by optical and scanning electronic microscopy, dispersive energy microanalysis, X-ray mapping, X-ray diffraction, and measurements of roughness and Vickers microhardness. Depending on the processing parameters, it is possible to obtain different microstructures. The affected area of gray cast iron, can be hardened by remelting or transformation hardening (total or partial) if the reached temperature is higher or not that of melting temperature. Laser treatment originated new structures such as retained austenite, martensite and, occasionally, eutectic of cellular dendritic structure. Aluminum-silicon alloy does not have phase transformation in solid state, it can be hardened only by remelting. The increase of hardness is a function of the precipitation hardening process, which makes the silicon particles smaller and more disperse in the matrix. Maximal values of microhardness (700-1000 HV) were reached with the laser treatment in gray cast iron samples. The initial microhardness is of 242 HV. For aluminum-silicon alloy, the laser remelting increases the initial microhardness of 128 HV to the range of 160-320 HV. The found results give a new perspective for using the CLA/IPEN's laser in the heat treatment area. Besides providing a higher absorptivity to the materials, compared with the CO{sub 2} laser, and optical fiber access, the superficial hardening with Nd:YAG laser, depending on the

  16. Effects of erbium-and chromium-doped yttrium scandium gallium garnet and diode lasers on the surfaces of restorative dental materials: a scanning electron microscope study.

    Hatipoglu, M; Barutcigil, C


    The aim of this study is to evaluate the potential effects of laser irradiation, which is commonly performed in periodontal surgery, on the surfaces of restorative materials. Five different restorative dental materials were used in this study, as follows: (1) Resin composite, (2) poly acid-modified resin composite (compomer), (3) conventional glass ionomer cement (GIC), (4) resin-modified glass ionomer cement (RMGIC), and (5) amalgam. Four cylindrical samples (8 mm diameter, 2 mm height) were prepared for each restorative material. In addition, four freshly extracted, sound human incisors teeth were selected. Two different laser systems commonly used in periodontal surgery were examined in this study: A 810 nm diode laser at a setting of 1 W with continuous-phase laser irradiation for 10 s, and an erbium-and chromium-doped yttrium scandium gallium garnet (Er, Cr: YSGG) laser at settings of 2.5 W, 3.25 W, and 4 W with 25 Hz laser irradiation for 10 s. Scanning electron microscopy (SEM) analysis was performed to evaluate the morphology and surface deformation of the restorative materials and tooth surfaces. According to the SEM images, the Er, Cr: YSGG laser causes irradiation markings that appear as demineralized surfaces on tooth samples. The Er, Cr: YSGG laser also caused deep defects on composite, compomer, and RMGIC surfaces because of its high power, and the ablation was deeper for these samples. High-magnification SEM images of GIC samples showed the melting and combustion effects of the Er, Cr: YSGG laser, which increased as the laser power was increased. In amalgam samples, neither laser left significant harmful effects at the lowest power setting. The diode laser did cause irradiation markings, but they were insignificant compared with those left by the Er, Cr: YSGG laser on the surfaces of the different materials and teeth. Within the limitations of this study, it can be concluded that Er, Cr: YSGG laser irradiation could cause distortions of the surfaces

  17. He-Ne laser effects on blood microcirculation. An in vivo study through laser doppler flowmetry; Efeito do laser de helio neonio sobre a microcirculacao sanguinea durante a reparacao tecidual. Estudo in vivo por meio de fluxometria laser doppler

    Nunez, Silvia Cristina


    Blood microcirculation performs an important function in tissue repair process, as well as in pain control, allowing for greater oxygenation of the tissues and the accelerated expulsion of metabolic products, that may be contributing to pain. Low Intensity Laser Therapy (LILT) is widely used to promote healing, and there is an assumption that it is mechanism of action may be due to an enhancement of blood supply. The purpose of this study was to evaluate, using laser Doppler flowmetry (LDF), the stated effects caused by radiation emitted by a He-Ne laser ({lambda}=632.8 nm) on blood microcirculation during tissue repair. To this end, 15 male mice were selected and received a liquid nitrogen provoked lesion, above the dorsal region, and blood flow was measured periodically, during 21 days. Due to radiation emission by the LDF equipment, a control group was established to evaluate possible effects caused by this radiation on microcirculation. To evaluate the He-Ne laser effects, a 1.15 J/cm{sup 2} dose was utilized, with an intensity of 6 mW/cm{sup 2}. The results obtained demonstrate flow alterations, provoked by the lesion, and subsequent inflammatory response. There was no statistical difference between the studied groups. As per the analysis of the results there is no immediate effect due the radiation emitted by a He Ne laser on microcirculation, although a percentage increase was observed in day 7 on medium blood flow rate in irradiated specimens. New studies are necessary to validate the use of this wavelength, in order to promote beneficial alterations in blood supply in radiated areas. (author)

  18. Estudo experimental da aplicação retiniana do laser infravermelho via transescleral sob condições de baixa visibilidade Transscleral infrared laser retinal photocoagulation experimental study under low visibility conditions

    Dario Grechi Goulart


    Full Text Available OBJETIVOS: Pesquisa experimental, com laser de diodo infravermelho, para estimar a segurança, a reprodutibilidade e a permeabilidade da parede ocular à sua atuação clínica, quando aplicado via transescleral, em condições de baixa visibilidade. MÉTODOS: Submetemos olhos de coelhos pigmentados da raça Nova Zelândia à fotocoagulação retiniana por laser de diodo infravermelho. No olho direito, realizamos fotocoagulação via transescleral sob parâmetros de potência e tempo pré-determinados clinicamente. No olho esquerdo, foram repetidos os mesmos valores da potência e tempo usados no olho direito, desta vez, via transpupilar. Imediatamente e após 2 meses, estudos clínicos baseados na retinografia e histopatológicos foram realizados. RESULTADOS: A permeabilidade da parede ocular, quando da aplicação do laser de diodo infravermelho via transescleral, variou entre 58,95 e 63,87%. A média da permeabilidade da parede ocular a 300 mW (63,14% mostrou-se significativamente superior àquela da permeabilidade da parede ocular encontrada a 500 mW (59,11%, (PPURPOSE: Retinal photocoagulation under poor visualization condition is often required. Transscleral infrared laser can be used as an alternative to regular transpupillary treatment. Based upon retinographic measurements, we proposed to estimate the reproducibility as well as ocular wall permeability rate for this treatment. Our primary goal was to evaluate whether this technique can deliver adequate photocoagulation at predetermined parameters without direct retinal visualization. METHODS: In New Zealand pigmented rabbits, optimal transscleral infrared diode laser settings were administered to the right eye. With the same parameters, transpupillary photocoagulation was repeated in the left eye. Retinographic and clinical examinations were performed immediately and two months later. RESULTS: Ocular wall permeability rate varied between 58.95 and 63.87%. Average permeability using a

  19. Tratamento de varizes com laser endovenoso: estudo prospectivo com seguimento de 39 meses Treatment of varicose veins with endovenous laser: a prospective 39-month follow-up study

    Luiz Marcelo Aiello Viarengo


    Full Text Available OBJETIVO: Avaliar os resultados da terapêutica endovenosa com laser no tratamento de varizes primárias. PACIENTES E MÉTODO: No período compreendido entre julho de 2001 e setembro de 2004 (39 meses, 253 pacientes (417 membros foram tratados ambulatorialmente com laser de diodo de 810 e 980-nm, com energia liberada endovenosamente através de fibra óptica introduzida por punção guiada por eco-Doppler. Foi utilizada anestesia por infiltração intumescente perivasal com solução de lidocaína a 0,2% (50-150 ml. A potência e duração do pulso foram determinadas pelo diâmetro da veia. Os controles foram realizados com eco-Doppler aos 7 dias, 1 mês, 3 meses, 6 meses, 1 ano e, a seguir, anualmente, para avaliar a eficácia do tratamento e os efeitos adversos. RESULTADOS: A oclusão primária da veia safena magna foi obtida em 405 dos 417 membros (97,1% tratados. Houve reintervenção em 12 casos (2,9%, com sucesso. O tempo médio de observação foi de 18 meses, e, nesse período, a taxa de recidiva global de varizes foi de 7,4%, sendo 6,3% (26 membros veias colaterais tributárias da crossa e 1,2% (cinco membros com recanalização da safena magna. Todas as recorrências ocorreram entre o terceiro e o 12º mês. Os efeitos indesejáveis mais freqüentes foram: equimoses (60,6%; dor suportável durante o procedimento (16,1%; hematomas (5,5%; flebite em colaterais não-tratadas (3,4%; hiperpigmentação (2,9%; e parestesia transitória (3,4%. Nenhum caso de tromboflebite da safena magna foi observado. Não houve nenhum caso de trombose venosa profunda ou embolia pulmonar. CONCLUSÃO: O tratamento endovenoso de varizes com laser, conforme descrito, foi eficaz para ocluir a safena magna e seus principais ramos, com efeitos adversos autolimitados e com recorrência inferior a 8% no período de seguimento.OBJETIVE: To evaluate results of endovenous laser treatment for primary varicose veins. PATIENTS AND METHOD: From July 2001 to September 2004

  20. Efeitos da radiação laser de dióxido de carbono em tecido ósseo: estudo macroscópico em ratos Effect of carbon dioxide laser radiation on osseous tissue: macroscopic study in rats



    Full Text Available O laser de dióxido de carbono (CO2, pelas suas propriedades intrínsecas, tem se tornado um instrumento cirúrgico importante; entre estas podemos citar: hemostasia, redução do edema e da dor pós-operatória e esterilização do campo cirúrgico. Seu uso em tecido ósseo para realização de osteotomias ainda é questionável, principalmente devido à possibilidade de iatrogenias causadas pelo aumento da temperatura tecidual, bem como destes efeitos na área paraincisional. O propósito deste estudo foi proporcionar a confecção de um plano piloto visando analisar macroscopicamente os efeitos da radiação laser de CO2 em tíbia de rato a fim de estabelecerem-se parâmetros de segurança quanto a potência. Foram utilizados 12 ratos. Após anestesia, os ossos foram submetidos a radiação com potência de 1, 3 e 5 watts. Os animais foram sacrificados nos tempos imediatamente após, 3, 7 e 14 dias após a irradiação, visando à remoção do osso tratado. Os espécimes obtidos foram observados através de lupa estereoscópica com aumentos de 14, 25 e 40 vezes e fotografados para posterior análise. Os resultados permitiram concluir que a potência de 1 watt proporciona uma melhor qualidade de resposta à reparação e que as potências de 3 e 5 watts provocaram o atraso na cronologia de reparo.The use of CO2 laser in osseous tissue to execute osteotomies is still questionable, mainly due to the increase of temperature in the site of irradiation. The purpose of this research was to carry out a pilot study in order to analyze macroscopically the effect of CO2 laser irradiation on rat tibia and to establish security parameters regarding power. Twelve rats were submitted to irradiation with 1, 3 and 5 watts of power and were examined immediately, 3, 7 and 14 days after irradiation. The results showed better healing when irradiation was carried out with the power of 1 watt; the 3- and 5-watt powers caused delay in the chronology of healing.

  1. Infrared laser sclerostomies.

    Ozler, S A; Hill, R A; Andrews, J J; Baerveldt, G; Berns, M W


    Four solid-state lasers with three fiberoptic delivery systems were used to perform laser sclerostomies in an acute-injury rabbit model and in fresh human globes. The lasers used were continuous-wave neodymium:yttrium aluminum garnet (YAG, 1.06 microns) and pulsed holmium:yttrium scandium galliam garnet (YSGG) (2.10 microns), erbium:YSGG (2.79 microns), and erbium:YAG (2.94 microns). Thermal damage to tissue and total laser energy required to produce sclerostomies decreased with increasing wavelength. In human tissue using a 600-microns fused silica fiberoptic, maximum thermal damage (greater than or equal to 100 microns) was noted at 1.06 microns with a total energy of 21 J at a power density of 2.5 kW/cm2. In addition, focal damage to the iris and ciliary body was noted at this wavelength. The least amount of thermal damage (15-20 microns) and lowest total energies needed were found at 2.94 microns. A 250-microseconds pulse length and pulse radiant exposures of 3.6 J/cm2 and 14.3 J/cm2 were used for the low hydroxyl-fused silica (500 microns) and zirconium fluoride (250 microns) fiberoptics, respectively. Although zirconium fluoride fibers have high through-put efficiencies that facilitate study of laser tissue interactions at 2.94 microns, problems encountered with fragility and solubility of the bare tip in aqueous media limit its usefulness. A high attenuation rate with the low hydroxyl-fused silica fiber limited its usable length to 35 cm at 2.94 microns. Tissue damage during sclerostomy formation was minimized at 2.94 microns, reaching a maximum at 1.06 microns. Minimizing tissue damage theoretically could decrease subconjunctival scarring and filtration failure.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Tissue tearing caused by pulsed laser-induced ablation pressure.

    Cummings, J P; Walsh, J T


    Pressure induced by ablative pulses of laser radiation is shown to correlate with the mechanical disruption of tissue. The ablation pressure induced during Er:YSGG laser irradiation of skin, liver, and aorta was calculated from a ballistic pendulum-based measurement of recoil momentum. The ejected material and ablation crater were examined grossly and microscopically after ablation. A gas-dynamic model of laser-induced vaporization was used to understand the measured pressures. The results show that mechanical disruption of tissue occurs when the ablation pressure exceeds the strength of the irradiated tissue at sites of intrinsic weakness.

  3. Estudo do efeito da irradiação com laser em baixa intensidade no metabolismo celular das glândulas salivares e na glicemia de ratas diabéticas induzidas por estreptozotocina

    Alyne Simões


    Considerando que o diabetes experimental altera a morfologia e função das glândulas salivares de ratos, o objetivo deste estudo foi analisar o efeito da irradiação com laser em baixa intensidade no metabolismo das glândulas parótidas (GP) e submandibulares (GSM) de ratas diabéticas, assim como analisar a glicemia destes animais. Ratas Wistar com aproximadamente 195 g foram divididas em diabéticas (D) e controles (C), e subdivididas de acordo com a dose de irradiação recebida: C-D0 (0 J/cm2), ...

  4. Efeito do laser em baixa intensidade sobre a modulação do processo inflamatório pós-cirúrgico: estudo clínico controlado randomizado

    Sierra, Simone Oliveira


    A dor, o edema e o espasmo muscular são complicações apresentadas por praticamente todos os pacientes após a cirurgia oral para a remoção de dentes inclusos, assim, este modelo tem sido amplamente utilizado para avaliar os efeitos do laser em baixa intensidade (LBI) no processo inflamatório gerado por este procedimento. O objetivo principal deste estudo foi avaliar amodulação do LBI na dor, edema, e espasmo muscular decorrentes da remoção de terceiros molares inferiores inclusos. Cinquenta p...

  5. Influence of the incidence angle on the morphology of enamel and dentin under Er:YAG laser irradiation; Estudo da influencia da angulacao do feixe laser na morfologia de esmalte e dentina irradiados com laser de Er:YAG

    Junqueira Junior, Duilio Naves


    The purpose of this study is to make an in vitro evaluation, using scanning electron microscopy, of the influence of the laser beam irradiation angle on the enamel and dentin morphology. These tissues were both irradiated by Er:YAG Laser, with the same energy parameter. Twenty-four incisive bovine teeth were used, separated in eight groups, four of enamel, and four of dentin, with three specimens in each group. Each specimen was submitted to three laser applications, varying the incidence angle, between the laser and the tooth surface, at 90, 50 and 20 degrees. The applied frequency was 2 Hz, with 20 pulses in each application. The KaVo Key Laser 3 was employed, wavelength at 2940 nm, adjustable energy from 40 to 600 mJ and repetition rate from 1 to 25 Hz. The groups were distributed according to the energy parameter as follows - enamel: 250 mJ; 300 mJ; 350 mJ and 400 mJ; dentin: 200 mJ; 250 mJ; 300 mJ and 350 mJ. The results evidenced the Laser incidence angle importance; it is an essential parameter in the protocol of utilization and it should not be disregarded. The observations of this study allow to conclude that the Laser incidence angle has direct influence on the morphological aspect of the alterations produced in enamel and dentin. (author)

  6. \\"Estudo dos efeitos da irradiação com lasers de alta potência e materiais de uso endodôntico em reabsorções radiculares externas simuladas\\"


    Este estudo avaliou, por meio de cultivo celular e MEV, a capacidade de adesão de fibroblastos e as alterações estruturais ocorridas na superfície dentinária de reabsorções radiculares externas simuladas, após tratamento com hidróxido de cálcio, MTA e/ou radiação com laser de diodo de alta potência e laser Er:YAG. Após a hemisecção das raízes de 31 dentes unirradiculares, foram realizadas cavidades padronizadas no terço cervical de cada secção, obtendo-se 62 amostras que foram divididas em 9 ...

  7. Thermal effects from modified endodontic laser tips used in the apical third of root canals with erbium-doped yttrium aluminium garnet and erbium, chromium-doped yttrium scandium gallium garnet lasers.

    George, Roy; Walsh, Laurence J


    To evaluate the temperature changes occurring on the apical third of root surfaces when erbium-doped yttrium aluminium garnet (Er:YAG) and erbium, chromium-doped yttrium scandium gallium garnet (Er,Cr:YSGG) laser energy was delivered with a tube etched, laterally emitting conical tip and a conventional bare design optical fiber tip. Thermal effects of root canal laser treatments on periodontal ligament cells and alveolar bone are of concern in terms of safety. A total of 64 single-rooted extracted teeth were prepared 1 mm short of the working length using rotary nickel-titanium Pro-Taper files to an apical size corresponding to a F5 Pro-Taper instrument. A thermocouple located 2 mm from the apex was used to record temperature changes arising from delivery of laser energy through laterally emitting conical tips or plain tips, using an Er:YAG or Er,Cr:YSGG laser. For the Er:YAG and Er,Cr:YSGG systems, conical fibers showed greater lateral emissions (452 + 69% and 443 + 64%) and corresponding lower forward emissions (48 + 5% and 49 + 5%) than conventional plain-fiber tips. All four combinations of laser system and fiber design elicited temperature increases less than 2.5 degrees C during lasing. The use of water irrigation attenuated completely the thermal effects of individual lasing cycles. Laterally emitting conical fiber tips can be used safely under defined conditions for intracanal irradiation without harmful thermal effects on the periodontal apparatus.

  8. Aggregation of subtropical soil under liming: a study using laser diffraction Agregação de um solo subtropical sob calagem: um estudo usando difração laser

    Edson Campanhola Bortoluzzi


    Full Text Available Laser diffraction (LD provides detailed analysis of particle size distribution. Its application to testing the stability of soil aggregates can assist studies on the aggregation of soils with contrasting electrochemical properties. The objectives of the present work were: (a to propose a protocol for using LD to study soil aggregation, (b to study the aggregation of an Acrisol under the influence of different doses and forms of lime. Samples were collected in 2005 from a Brazilian Acrisol that in 1994 had received 0.0; 2.0; 8.5 and 17.0 Mg ha-1 of lime, left on the soil surface or incorporated. Aggregates from 4.76 to 8.00 mm diameters were studied using the traditional method proposed by Kemper & Chepil (1965, with wet sieving, while aggregates from 1.00 to 2.00 mm were studied using a CILAS® laser diffractometer that distinguishes particles ranging from 0.04 to 2,500.00 μm. LD readings were made after six consecutive pre-treatments, using agitation times, a chemical dispersion agent and ultrasound. Mean Weighted Diameter (MWD and the Aggregate Stability Index (ASI calculated, using the traditional method does not discriminate the treatments. However, LD is able to produce detailed data on soil aggregation, resulting in indexes of stability of aggregates that are linearly related to the doses of lime applied (MWD: R² = 0.986 and ASI: R² = 0.876. It may be concluded that electrochemical changes in the Brazilian Acrisol resulting from incorporated lime affect the stability of aggregates, increasing stability with increased doses of lime.A difração de raios laser (DL oferece grande detalhamento da distribuição de tamanho de partículas. Sua aplicação em testes de estabilidade de agregados de solo pode auxiliar o estudo sobre a agregação de solos com propriedades eletroquímicas discrepantes. Nesse sentido, os objetivos do presente trabalho foram: propor um protocolo de uso da DL para estudar a agregação do solo; e estudar a influ

  9. Effects of different lasers on organic/inorganic ratio of radicular dentin.

    Lopes, F C; Roperto, R; Akkus, A; Akkus, O; Souza-Gabriel, A E; Sousa-Neto, M D


    The aim of this study was to evaluate the chemical stability of endodontic-treated root dentin after different laser irradiations through Raman spectroscopy. Fifty maxillary canines were selected and prepared with K3 system. Roots were randomly distributed into five groups (n = 10) according to the surface treatment: GI (water), GII (NaOCl + EDTA), GIII (NaOCl + EDTA + 980 nm Diode laser), GIV (NaOCl + EDTA+ 1064 nm Nd: YAG laser) and GV (NaOCl + EDTA+ 2780 nm Er,Cr: YSGG laser). Lasers were applied for 20 s. Samples were bisected, and the organic and inorganic content of dentin was analyzed by Raman spectroscopy. Data were submitted to ANOVA and Tukey tests (p laser had a reduced collagen content (GV-290.7 ± 41.7) compared with the water-treated roots (GI-328.3 ± 63.5) and those treated with NaOCl + EDTA (GII-333.9 ± 55.8). Roots irradiated with Er,Cr: YSGG laser also showed a higher inorganic/organic ratio (GV-9.5 ± 1.1) than roots treated with water (GI-7.7 ± 1.5), NaOCl + EDTA (GII-8.0 ± 1.4) and diode laser (GIII-8.2 ± 1.6). Both organic and inorganic contents increased from cervical to apical thirds in all groups. None of the surface treatments were able to promote changes in the inorganic content of the root dentin; treatment with NaOCl + EDTA combined with Er,Cr: YSGG altered collagen.

  10. A method for rapid measurement of laser ablation rate of hard dental tissue

    Perhavec, T.; Gorkič, A.; Bračun, D.; Diaci, J.


    The aim of the study reported here is the development of a new method which allows rapid and accurate in-vitro measurements of three-dimensional (3D) shape of laser ablated craters in hard dental tissues and the determination of crater volume, ablation rate and speed. The method is based on the optical triangulation principle. A laser sheet projector illuminates the surface of a tooth, mounted on a linear translation stage. As the tooth is moved by the translation stage a fast digital video camera captures series of images of the illuminated surface. The images are analyzed to determine a 3D model of the surface. Custom software is employed to analyze the 3D model and to determine the volume of the ablated craters. Key characteristics of the method are discussed as well as some practical aspects pertinent to its use. The method has been employed in an in-vitro study to examine the ablation rates and speeds of the two main laser types currently employed in dentistry, Er:YAG and Er,Cr:YSGG. Ten samples of extracted human molar teeth were irradiated with laser pulse energies from 80 mJ to the maximum available energy (970 mJ with the Er:YAG, and 260 mJ with the Er,Cr:YSGG). About 2000 images of each ablated tooth surface have been acquired along a translation range of 10 mm, taking about 10 s and providing close to 1 million surface measurement points. Volumes of 170 ablated craters (half of them in dentine and the other half in enamel) were determined from this data and used to examine the ablated volume per pulse energy and ablation speed. The results show that, under the same conditions, the ablated volume per pulse energy achieved by the Er:YAG laser exceeds that of the Er,Cr:YSGG laser in almost all regimes for dentine and enamel. The maximum Er:YAG laser ablation speeds (1.2 mm 3/s in dentine and 0.7 mm 3/s in enamel) exceed those obtained by the Er,Cr:YSGG laser (0.39 mm 3/s in dentine and 0.12 mm 3/s in enamel). Since the presented method proves to be easy to

  11. Erbium, chromium:yttrium scandium gallium garnet laser for caries removal: influence on bonding of a self-etching adhesive system.

    Tachibana, Arlene; Marques, Márcia Martins; Soler, Julia Maria Pavan; Matos, Adriana Bona


    This study evaluated the influence of the dental substrates obtained after the use of different caries removal techniques on bonding of a self-etching system. Forty, extracted, carious, human molars were ground to expose flat surfaces containing caries-infected dentine surrounded by sound dentine. The caries lesions of the specimens were removed or not (control--G1) either by round steel burs and water-cooled, low speed, handpiece (G2), or by irradiation with an erbium, chromium:yttrium scandium gallium garnet (Er,Cr:YSGG) laser (2W, 20 Hz, 35.38 J/cm(2), fiber G4 handpiece with 0.2826 mm(2), non-contact mode at a 2 mm distance, 70% air/20% water--G3) or using a chemo-mechanical method (Carisolv--G4). Caries-infected, caries-affected and sound dentines were submitted to a bonding system followed by construction of a resin-based composite crown. Hour-glass shaped samples were obtained and submitted to a micro-tensile bond test. The bond strength data were compared by analysis of variance (ANOVA), complemented by Tukey's test (P bond strengths than did samples of caries-affected dentine, except for the groups treated with the Er,Cr:YSGG laser. The highest bond strengths were observed with the sound dentine treated with burs and Carisolv. The bond strengths to caries-affected dentine were similar in all groups. Additionally, bonding to caries-affected dentine of the Er,Cr:YSGG laser and Carisolv groups was similar to bonding to caries-infected dentine. Thus, caries-affected dentine is not an adequate substrate for adhesion. Moreover, amongst the caries removal methods tested, the Er,Cr:YSGG laser irradiation was the poorest in providing a substrate for bonding with the tested self-etching system.

  12. Estudo teórico da estrutura eletrônica e da dinâmica induzida por lasers da molécula de HCl

    Vinícius V. Cruz


    Full Text Available Potential energy and dipole moment curves for the HCl molecule were computed. Calculations were performed at different levels of theory (DFT, MRCI. Spectroscopic properties are reported and compared with experimental data, for validating the theoretical approaches. Interaction of infrared radiation with HCl is simulated using the wave packet formalism. The quantum control model for population dynamics of the vibrational levels, based on pi-pulse theory, is applied. The results demonstrate that wavepackets with specific composition can be built with short infrared laser pulses and provide the basis for studies of H + HCl collision dynamics with infrared laser excitation.

  13. Cicatrização da membrana timpânica na timpanocentese com laser de argônio comparado à técnica com microlanceta: estudo experimental em ratos Tympanic membrane healing in myringotomies performed with argon laser or microknife: an experimental study in rats

    Lucio Almeida Castagno


    Full Text Available Otite média secretora (OMS e otite média aguda recorrente (OMAR podem necessitar tratamento cirúrgico para adequada ventilação da orelha média. A abertura clássica do tímpano (timpanocentese requer incisão por microlanceta sob controle de microscópio cirúrgico e mantém-se patente por alguns dias. Estudos recentes sugerem que a timpanocentese feita por diferentes lasers pode permanecer permeável por maior tempo, o que possibilitaria a normalização da otite média. MATERIAL E MÉTODOS: Neste estudo experimental 34 ratos linhagem Wistar, albinos, machos adultos pesando cerca de 300g, foram anestesiados com cetamina 27 mg/kg e xilazina 2,7 mg/kg. A seguir, foram submetidos à timpanocentese incisional com microlanceta no ouvido direito (ML-OD, e à timpanocentese mediada por laser de argônio no ouvido esquerdo (LA-OE. RESULTADOS: Não houve diferença significativa no tempo de cicatrização das timpanocenteses feitas com laser de argônio ou microlanceta. Todas as timpanocenteses cicatrizaram em 10 dias. CONCLUSÃO: A timpanocentese com laser de argônio apresentou patência e cicatrização semelhantes à técnica clássica com microlanceta realizada em ratos Wistar sem enfermidades de orelha média.Secretory otitis media (SOM and recurrent acute otitis media (RAOM may require surgical treatment to proper ventilate the middle ear. Incisional myringotomy is usually done under microscopy with a micro-knife , but it remains patent for just a few days. Recent research indicates that laser assisted myringotomies remain open much longer, allowing middle ear ventilation and healing. MATERIAL AND METHODS: In this experimental study 34 white, male, adult, Wistar rats, without middle ear disease were submited to anesthesia with ketamine 27 mg/kg and xylazine 2,7 mg/kg. Incisional myringotomy was done on the right ear, while laser myringotomy was done on the left. Myringotomies were evaluated periodically until healing. RESULTS: The healing

  14. Root Surface Bio-modification with Erbium Lasers- A Myth or a Reality??

    Lavu, Vamsi; Sundaram, Subramoniam; Sabarish, Ram; Rao, Suresh Ranga


    The objective of this literature review was to critically review the evidence available in the literature regarding the expediency of erbium family of lasers for root bio modification as a part of periodontal therapy. The literature search was performed on the Pubmed using MeSH words such as "lasers/therapeutic use, scaling, dental calculus, tooth root/anatomy and histology, ultrasonic therapy". The studies were screened and were grouped as follows: those evaluating a) efficacy for calculus removal with the Erbium family of laser b) root surface changes following Er YAG and Er Cr YSGG application c) comparative studies of the Er YAG, Er Cr YSGG lasers versus conventional methods of root surface modification d) Bio compatibility of root surface following Erbium laser treatment e) Studies on the combined efficacy of laser root modification with conventional methods towards root surface bio-modification f) Studies on effectiveness of root surface bio-modification prior to root coverage procedures. In conclusion, the erbium family has a proven anti-bacterial action, predictable calculus removal, minimal root substance removal, and appears to favor cell attachment. The Erbium family of lasers appears to be a useful adjunct for the management of periodontal disease.

  15. Estudo morfológico de superfícies ósseas após secção por pontas diamantadas ou laser de érbio: YAG Morphological evaluation of bone surfaces after sectioning with diamond points or erbium: YAG laser

    Massuji KURAMOTO Jr.


    Full Text Available O objetivo deste trabalho foi analisar morfologicamente as superfícies ósseas resultantes da secção por pontas diamantadas ou por laser de érbio:YAG. Cinco ratos (Rattus norvegicus albinus foram sacrificados por dose letal de fenobarbital. Após a execução deste procedimento, os ossos predeterminados foram submetidos à secção por pontas diamantadas ou por laser de érbio:YAG em uma energia de 300 mJ por pulso e taxa de repetição de 2 Hz. As amostras foram submetidas a análise em microscópio eletrônico de varredura, revelando a existência de um padrão para as secções obtidas com cada instrumento, sendo verificada uma superfície mais regular nas amostras seccionadas com o laser de érbio:YAG. Em aumentos da ordem de 3000 vezes, pode-se observar indícios de fusão e seqüente solidificação das superfícies seccionadas por meio do laser de érbio:YAG. Conclui-se que o laser de érbio:YAG foi eficaz na remoção de tecido ósseo, mas que, nos parâmetros utilizados neste estudo, foi responsável por alterações morfológicas sugestivas de significativo aumento de temperatura, não devendo ser indicado, nestas condições, para a execução de secções ósseas.The purpose of this study was to analyze bone surfaces cut by Er:YAG laser or by diamond points. Five male rats (Rattus norvegicus albinus were killed by lethal dose of phenobarbital, and selected bones were cut by Er:YAG laser at 300 mJ and 2 Hz, or by diamond points. The samples were submitted to evaluation through SEM at standard magnifications. By analyzing the surfaces, the authors could observe a pattern for each group, with a smoother surface in the laser cut group than in the diamond cut group. In higher magnifications, the images suggest melting and solidifying in the laser group. The authors conclude that the laser was effective in bone cutting. However, it was responsible for morphological changes that suggest a significant temperature increase.

  16. In vitro study of temperature changes in root during Er:YAG laser application; Estudo in vitro da alteracao da temperatura durante a aplicacao do Er:YAG laser intracanal

    Brandao, Redson Vilela


    The temperature increase in root dentine irradiated by Er:YAG laser beam was analyzed, for different dentine thickness and different energy and frequency conditions, aiming the evaluation of Er:YAG laser in endodontic therapy, without causing any damages to close tissues. Twenty four human teeth were separated in four groups with six teeth each, and longitudinally sectioned in thickness of 0.5 mm (first group), 1,0 mm (second group), 1,5 mm (third group) and 2,0 mm (fourth group). Those samples were irradiated with the Er:YAG laser, emitting at the wavelength of 2.94{mu}m, by using a sapphire optic fiber with diameter of 0.375 mm, and forming an angle of 5 deg with the irradiated dentine surface. Three different laser energies were used in this study, 180 mJ, 160 mJ and 140 mJ, with frequencies of 10 Hz and 15 Hz. The temperature data were collected in a digital-analog system and sent to a computer for analysis. It was verified that the time for temperature increases of 5 deg in the external root walls varies according to the laser energy, repetition rate and dentine root thickness. Thus, in this work we could obtain laser parameters to avoid thermal damages in periodontal tissues. (author)

  17. Measurements of erbium laser-ablation efficiency in hard dental tissues under different water cooling conditions.

    Kuščer, Lovro; Diaci, Janez


    Laser triangulation measurements of Er:YAG and Er,Cr:YSGG laser-ablated volumes in hard dental tissues are made, in order to verify the possible existence of a "hydrokinetic" effect that has been proposed as an alternative to the "subsurface water expansion" mechanism for hard-tissue laser ablation. No evidence of the hydrokinetic effect could be observed under a broad range of tested laser parameters and water cooling conditions. On the contrary, the application of water spray during laser exposure of hard dental material is observed to diminish the laser-ablation efficiency (AE) in comparison with laser exposure under the absence of water spray. Our findings are in agreement with the generally accepted principle of action for erbium laser ablation, which is based on fast subsurface expansion of laser-heated water trapped within the interstitial structure of hard dental tissues. Our measurements also show that the well-known phenomenon of ablation stalling, during a series of consecutive laser pulses, can primarily be attributed to the blocking of laser light by the loosely bound and recondensed desiccated minerals that collect on the tooth surface during and following laser ablation. In addition to the prevention of tooth bulk temperature buildup, a positive function of the water spray that is typically used with erbium dental lasers is to rehydrate these minerals, and thus sustaining the subsurface expansion ablation process. A negative side effect of using a continuous water spray is that the AE gets reduced due to the laser light being partially absorbed in the water-spray particles above the tooth and in the collected water pool on the tooth surface. Finally, no evidence of the influence of the water absorption shift on the hypothesized increase in the AE of the Er,Cr:YSGG wavelength is observed.

  18. Efeitos od laser CO2 na mandíbula de ratos: Estudo através da microscopia eletrônica de varredura

    LIBERTI Edson Aparecido


    Full Text Available A face lateral do corpo da mandíbula de ratos foi irradiada pelo laser CO2 com disparos contínuos de 10watts de potência. Após três meses, o sulco formado pela irradiação apresentou, em uma grande extensão, material fundido com diversas fraturas. Após sete meses, o periósteo neoformado recobriu amplas áreas da incisão, que apresentou ainda material carbonizado. Um ano após a incisão, o periósteo neoformado estava composto por fibras colágenas, que formaram feixes espessos, transversais à incisão, ou malhas regulares, que recobriram a incisão. Ainda nessa fase, resquícios de material carbonizado foram verificados, caracterizando um retardo na regeneração óssea

  19. In vitro study of hydroxy apatite and enamel powder fused in human enamel by Nd:YAG laser; Estudo in vitro da fusao de hidroxiapatita e esmalte em superficies de esmalte humano pelo laser de Nd:YAg

    Ferrreira, Marcus Vinicius Lucas


    The aim of this study was to evaluate the effects of pulsed Nd:YAG (1064 nm) laser irradiation on hydroxyapatite and enamel powder fusion. This laser beam is not well absorbed by this two compounds for this reason they were mixed with vegetal coal to increase the absorption of the laser beam. Fifteen enamel flat surfaces and six occlusal enamel surfaces were prepared with three different substances: hydroxyapatite mixed with vegetal coal (3:1 in weigh); enamel powder mixed with vegetal coal (3:1 in weigh); vegetal coal. The occlusal surfaces were utilized to determine if the compounds could seal pits and fissures. Flat surfaces were utilized to determine fusion of hydroxyapatite and enamel powder. All samples were irradiated with Nd:YAG laser with the parameters: 80 mJ, 15 Hz, 1,2 W, 100 {mu}s pulse-width, 131,1 J/cm{sup 2}. Laser beam was delivered to the samples with a 300 {mu}m diameter fiber optic. Morphology of the irradiated surfaces were examined by scanning electron microscopy (SEM). The compounds with hydroxyapatite and enamel powder were fused to enamel surfaces. Only partial pits and fissures sealing could be observed. (author)

  20. 'In vitro' study of the efficacy of diode laser and LED irradiation during dental bleaching; Estudo 'in vitro' da acao do LED e laser de diodo no clareamento dental

    Barroso, Marcia Cristina da Silva


    This in vitro study evaluated the efficacy of LED and laser diode irradiation during the dental bleaching procedure, using two bleaching agents (Opalescence X-tra and HP Whiteness). The diode laser and the LED were operated in the continuous mode, with wavelength of 808 nm and 470 nm, respectively. The results of the irradiations were characterized with the CIELAB system calculating the L{sup *}a{sup *}b{sup *} values for the darkened and the bleached teeth (60 bovine incisors). This is to our knowledge the first time that light sources laser and LED are compared with respect to their whitening capability when applied to different agents. Significant differences in the chroma value are obtained for the two whitening agents and for the different light sources, too. Also, in terms of luminance, the combination of laser/ Whiteness HP showed significantly better results than when the same agent was used alone or in combination with LED. Best overall results are obtained with the combination of Whiteness HP and laser. (author)

  1. Clinical study on the removal of gingival melanin pigmentation: comparison between Nd:YAG laser ablation and mechanical abrasion; Estudo clinico comparativo entre as tecnicas de despigmentacao melanica gengival: laser neodimio (1064 nm) e gengivoabrasao

    Lopes, Luis Mario de Melo


    Melanin pigmentation occurs as a result of excessive deposition of melanin, produced by the melanocytes present in the basal layer of the epithelium. This study compares clinical parameters such as inflammation and/or hemorrhage, healing process and re-pigmentation, caused by the Nd:YAG laser ablation and the mechanical abrasion of the melanin, by means of photographic images, taken during the first 30 days after the treatment. The patients comfort was monitored during the first ten days after the treatment using the method of the Visual Analog Scale to measure the pain. Six patients with gingival melanin pigmentation were selected. The left upper gingival quadrant was treated with the Nd:YAG laser using 125 mJ per pulse and 20 Hz, the right upper gingival quadrant received mechanical abrasion and the lower quadrants served for control. Both techniques did not result in inflammation and/or hemorrhage. The healing process was slower with the laser. Using mechanical abrasion, ali patients showed remaining pigmentation or re-pigmentation of varying intensity after a period of 30 days. With the laser 50 % of the patients did not show any re-pigmentation after this period. The pain analysis showed that the pain sensed 24 hours after the treatment with the laser is higher than using mechanical abrasion. (author)

  2. Effects of the low-intensity red laser radiation on the fluoride uptake in enamel. A clinical trial; Avaliacao dos efeitos da radiacao laser de emissao vermelha em baixa intensidade na incorporacao de fluor no esmalte. Estudo clinico

    Nakasone, Regina Keiko


    Fluoride has been the most important preventive method on development of the caries. This in vivo study evaluated the effects of low-intensity red laser radiation on the fluoride uptake in enamel. Ten healthy participants were recruited for this study. The two maxillary central incisors of each volunteer to be biopsied were used and divided into 4 groups: group G{sub C} (control, which was untreated; group G{sub F} (fluoride), which received topical acidulated phosphate fluoride (APF) 1,23% treatment for 4 minutes; group G{sub LF} (laser + fluoride), which was irradiated with a low-intensity diode laser ({lambda}= 660 nm and dose= 6 J/cm{sup 2}) with APF application after irradiation and group G{sub FL} (fluoride + laser), which received APF before irradiation using the same parameters as G{sub LF}. The determination of fluoride was performed using a fluoride ion electrode after an acid-etch enamel biopsy. The results show a significant increase of the fluoride uptake in enamel for groups G{sub F}, G{sub LF} and G{sub FL} when compared to control group. Although a percentage increase of 57% was observed for G{sub LF} with respect to G{sub F}, there were no statistical differences among treated groups. These findings suggest that low-intensity laser radiation used before APF could be employed in the clinical practice to prevent dental caries. (author)

  3. Aplicaciones de los láseres de Er:YAG y de Er,Cr:YSGG en odontologia

    Revilla Gutiérrez, Verónica; España Tost, A. J. (Antonio Jesús); Arnabat Domínguez, Josep; Gay Escoda,Cosme


    Los láseres de Er:YAG y de Er,Cr:YSGG por su longitud de onda son bien absorbidos, tanto por el agua que contienen los tejidos blandos como por los cristales de hidroxiapatita presentes en los tejidos duros. Estas características hacen posible que estos láseres puedan ser absorbidos por los tejidos duros. Se presentan los múltiples usos y aplicaciones que tiene esta tecnología en Odontología, tanto en cirugía de tejidos blandos, como sus aplicaciones sobre tejidos duros, como por ejemplo los ...

  4. Effects of low intensity laser radiation on osteointegration mechanism of implants: study 'in vivo'; Efeitos da radiacao laser em baixa intensidade no mecanismo de osseointegracao de implantes: estudo 'in vivo'

    Blay, Alberto


    The purpose of this study is to determine whether the process of bone integration of implants placed in rabbit tibia is changed in any way if the region is radiated with laser, as compared to the time required for the bone integration process without radiation. Thirty adult male white New Zealand rabbits were submitted to implant surgery, for subsequent evaluation of the removal torque and resonance frequency. Each animal received two implants of pure titanium, one in each proximal metaphysics of the tibia, which were inserted with a 40 Ncm torque, and their initial stability was also monitored by means of a resonance frequency analyzer. The rabbits were then divided into 3 groups: one control group and two laser groups. The groups were evaluated in regard to removal torque and resonance frequency of the implants, after 3 and 6 weeks. One of the laser groups was radiated with a laser beam of a wavelength in the infrared range (830 nm) and the other group was radiated with a laser beam emitted in the visible range (680 nm). Ten radiation sessions were performed, 48 hours apart, the first of them during the immediate post-operation period. Radiation energy density was 4 J/cm{sup 2} per point, and there were two points at each side of the tibia. Results of the statistical analysis of the resonance frequency indicated that for both laser groups there was a significant difference between frequency values at the time of implant and the values obtained after 3 and 6 weeks. Furthermore, the results obtained for the removal torque of the three groups showed a statistically significant difference after a period of 6 weeks; removal torque values for the laser groups were, in the average, much greater than those of the control group. From these results it is possible to conclude that implants in rabbit tibia, that were exposed to laser radiation with wavelengths of 680 nm and 830 nm, had a better degree of bone integration than the control group.(author)

  5. In vitro study of morphological and chemical modification threshold of bovine dental enamel irradiated by the holmium laser; Estudo in vitro das alteracoes morfologicas e quimicas do esmalte dental bovino irradiado pelo laser de holmio

    Eduardo, Patricia Lerro de Paula


    The aim of this study is to investigate the Ho:YLF laser effects on the dental enamel surface with regards to its morphology, thermal variations during its irradiation in the pulp chamber and its increased resistance to demineralization through quantitative analysis of calcium and phosphorous atoms reactive concentrations in samples. Twenty samples of bovine enamel were used and divided in four groups: control - acidulated phosphate fluoride (APF) application followed by demineralization treatment with lactic acid; irradiation with Ho:YLF laser (100 J/cm{sup 2}) followed by APF topic application and demineralization treatment with lactic acid; irradiation with Ho:YLF laser (350 J/cm{sup 2}) followed by APF topic application and demineralization treatment with lactic acid: and irradiation with Ho:YLF laser ( 450 J/cm{sup 2}) followed by APF topic application and demineralization treatment with lactic acid. Ali samples were quantified according to their calcium and phosphorous atoms relative concentrations before and after the treatments above. X-Ray fluorescence spectrochemical analysis and scanning electron microscopy were carried out. It was observed an increase on the calcium and phosphorous atoms concentration ratio and therefore the enamel demineralization reduction as a result of the lactic acid treatment in the samples irradiated with the holmium laser followed by the APF application. In order to evaluate the feasibility of this study for clinical purposes, morphological changes caused by the holmium laser irradiation were analyzed. Such modifications were characterized by melted and re-solidified regions of the enamel with consequent changes on its permeability and solubility. Temperature changes of ten human pre-molars teeth irradiated with 350 J/cm{sup 2} and 450 J/cm{sup 2} were also monitored in the pulp chamber in real time. Temperature increases over 4,20 C did not occur. The results obtained from this study along with the results from previous

  6. Morphological change study on root surfaces treated with curettes, sonic instruments or Er:YAG laser; Estudo in vitro da alteracao morfologica em superficie radicular tratada com curetas, aparelho ultrasonico ou com laser de Er:YAG

    Guimaraes Filho, Arlindo Lopes


    Periodontal disease is caused by dental plaque and dental calculus on roots surfaces, specially on cervical areas. As dental plaque is the main cause and dental calculus a secondary one, it is practically impossible to separate one factor to the other one. In order to get periodontal tissue health it is necessary to eliminate dental plaque and calculus from root surfaces. In this sense, Er:YAG laser comes in as an excellent way to control periodontal disease, not only, by removing calculus and dental plaque but also for its bacteria reduction. The aim of this study is to compare, by S.E.M., root surfaces changing when they are treated with curettes and ultrasonic scaling or Er:YAG laser irradiation with two different energy levels of 60 mJ/pulse and 100 mJ/pulse and repetition tax of 10 Hz (in the display). It is also objective of this study to check a possible thermic damage to pulp tissue when the roots surfaces are irradiated with Er:YAG laser. We used for this study, five human dental roots, each one of them were cut into four samples, giving us a total of twenty samples, which were divided in five groups of four samples each one. The control group, we did not indicated any kind of treatment. The first group, the roots samples were scaled and planned with Gracey curettes 5/6 and 7/8. The second group, the roots samples were treated with ultrasonic instruments. The third group was irradiated with Er:YAG laser using 60 mJ/pulse , 10 Hz and energy density of 4 J/cm{sup 2} (approximated). The fourth group was irradiated with Er:YAG laser using 100 mJ/pulse, 10 Hz and energy density of 7 J/cm{sup 2} (approximated). The results analysis showed that roots scaling either with Gracey curettes or with ultrasonic instruments created smear layer covering roots surfaces; roots surfaces irradiated with Er:YAG laser showed few roughness in the third group; roots surfaces irradiated with Er:YAG laser showed no smear layer and the Er:YAG laser irradiation did not bring any

  7. Action of diode laser (830 nm) on cutaneous wound healing process: biometrical and histological study in rats; Acao do diodo laser emitindo em 830 nm, sobre o processo de cicatrizacao de lesoes cutaneas: estudo biometrico e histologico em ratos

    Rezende, Sandra Bastos


    In this research, it was analyzed the acceleration of the healing process of cutaneous lesions in mice, using a diode laser emitting in 830 nm. The 64 selected animals in this study were randomically divided into four groups of 16 animals each (G1, G2, G3 and G4). Biometric and histological comparisons were accomplished in the following periods: 3, 7 and 14 days after the surgery and laser application. Three laser irradiation configurations were used: a punctual contact (G2) and two non-contact and uniform (G3 and G4). For group G2, the laser intensity was 428 mW/cm{sup 2} , and for groups G3 and G4 it was 53 mW/cm{sup 2}. The total doses were D = 3 J/cm{sup 2} for groups G2 and G4, and D = 1,3 J/cm{sup 2} for G3. The first group, G1, was considered control and thus not submitted to any treatment after the surgery. All irradiated lesions presented acceleration of the healing process with regard to the control group. However, our results clearly indicate that the smaller laser intensity (uniform irradiation) leaded to the best results. On the other hand, the smaller used dose also leaded to the more significant and expressive results. The combination of the intensity value of 53 mW/cm{sup 2} and the dose of 1,3 J/cm{sup 2} leaded to optimal results, regarding the Biometric and histological analysis, presenting faster lesion contraction, quicker neoformation of epithelial and conjunctive tissue (with more collagen fibers ). (author)

  8. In vitro study of the diode laser effect on artificial demineralized surface of human dental enamel; Estudo in vitro do efeito do laser diodo sobre a superficie de esmalte dental humano desmineralizado artificialmente

    Ebel, Patricia


    In scientific literature there are many reports about fusion and resolidification of dental enamel after laser irradiation and their capability to generate surfaces with increased resistance to demineralization compared to non-irradiated areas. The use of high power diode laser on demineralized surfaces of human dental enamel is presented as a good alternative in caries prevention. The purpose of this study is to investigate the morphological changes produced by the use of one high power diode laser on human dental enamel surface after demineralization treatment with lactic acid, under chosen parameters. Fifteen samples of human dental molars were used and divided in four groups: control - demineralization treatment with lactic acid and no irradiation, and demineralization treatment with lactic acid followed of irradiation with 212,20 mJ/cm{sup 2}, 282,84 mJ/cm{sup 2} and 325,38 mJ/cm{sup 2}, respectively. The samples were irradiated with high power diode laser (808 nm) with a 300 {mu}m diameter fiber optics. Black ink was used on enamel surface to enhance the superficial absorption. The samples were studied by optical microscopy and scanning electron microscopy. Modifications on the enamel surfaces were observed. Such modifications were characterized by melted and re-solidified region of the enamel. According with our results the best parameter was 2.0 W, presenting the most uniform surface. The use of high power diode laser as demonstrated in this study is able to promote melting and re-solidification on human dental enamel. (author)

  9. [Lasers].

    Passeron, T


    Lasers are a very effective approach for treating many hyperpigmented lesions. They are the gold standard treatment for actinic lentigos and dermal hypermelanocytosis, such as Ota nevus. Becker nevus, hyperpigmented mosaicisms, and lentigines can also be successfully treated with lasers, but they could be less effective and relapses can be observed. However, lasers cannot be proposed for all types of hyperpigmentation. Thus, freckles and café-au-lait macules should not be treated as the relapses are nearly constant. Due to its complex pathophysiology, melasma has a special place in hyperpigmented dermatoses. Q-switched lasers (using standard parameters or low fluency) should not be used because of consistent relapses and the high risk of post-inflammatory hyperpigmentation. Paradoxically, targeting the vascular component of the melasma lesion with lasers could have a beneficial effect. However, these results have yet to be confirmed. In all cases, a precise diagnosis of the type of hyperpigmentation is mandatory before any laser treatment, and the limits and the potential side effects of the treatment must be clearly explained to patients. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  10. Lasers.

    Passeron, T


    Lasers are a very effective approach for treating many hyperpigmented lesions. They are the gold standard treatment for actinic lentigos and dermal hypermelanocytosis, such as Ota nevus. Becker nevus, hyperpigmented mosaicisms, and lentigines can also be successfully treated with lasers, but they could be less effective and relapses can be observed. However, lasers cannot be proposed for all types of hyperpigmentation. Thus, freckles and café-au-lait macules should not be treated as the relapses are nearly constant. Due to its complex pathophysiology, melasma has a special place in hyperpigmented dermatoses. Q-switched lasers (using standard parameters or low fluency) should not be used because of consistent relapses and the high risk of post-inflammatory hyperpigmentation. Paradoxically, targeting the vascular component of the melasma lesion with lasers could have a beneficial effect. However, these results have yet to be confirmed. In all cases, a precise diagnosis of the type of hyperpigmentation is mandatory before any laser treatment, and the limits and the potential side effects of the treatment must be clearly explained to patients. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  11. Estudo comparativo das extensões das lesões causadas por duas e quatro passadas de laser Erbium em ratos Wistar com 0% de sobreposição dos spots Comparative study of alterations found in 2 and 4 Erbium: YAG laser passes in Wistar rats with 0% overlap of spots

    Lúcia de Noronha


    Full Text Available Lasers de CO2 tem sido apresentados com a finalidade de rejuvenecer a face através do resurfacing. Embora cada sistema de laser tenha o mesmo princípio básico, há significativa diferença entre os lasers que pode resultar em variações no efeito tecidual clínico e histológico. O laser Erbium:YAG que tem como característica o comprimento de onda com 10 vezes mais afinidade pela água que o laser de CO2. O propósito deste estudo experimental foi comparar as alterações morfométricas encontradas em 2 e 4 passadas com laser Erbium:YAG com sobreposição de 0% dos spots. Foi avaliada a homogeneidade da ablaçãoem comprimento e usou-se a pele do dorso de 3 ratos in vivo. Foi selecionada uma área de pele controle de cada rato. Finalmente, num período máximo de 3 horas, a pele foi ressecada e encaminhada à histopatologia para as avaliações propostas. Como resultados com 4 passadas houve mais homogeneidade da extensão da ablação do que em 2 passadas. Conclui-se que a extensão e homogeneidade de ablação foi maior com 4 passadas. A utilização de 0% de sobreposição dos spots não garante homogeneidade de ablação.CO2 lasers has been presented with the purpose of rejuvenating the face by means of resurfacing. Though each laser systems has the same base principle, there is a significant difference among lasers which could result in variations in the clinical and histological effects of the tissue. The Erbium:YAG laser has the characteristic of having the wavelength with 10 times more affinity for water than the CO2 laser. The purpose of this experimental study was to compare the morphometric alterations found in 2 and 4 Erbium:YAG laser passes with 0% overlap of spots. It was evaluated the homogeneity of ablation in length and was used the dorsal skin of 3 living mice. It was selected a control area in each mouse. Finally, in the maximum period of three hours, the skin was resected and sent to histopathology for evaluations

  12. Neocolagenização induzida pelo resurfacing com laser erbium:YAG isolado e associado a lifting cutâneo: estudo morfométrico comparativo em ratos Comparison of single erbium:YAG laser resurfacing to a combination with cutaneous lifting: a morphometric study of neocollagenization in rats

    Lucia Noronha


    Full Text Available INTRODUÇÃO: Diferente do lifting, cuja tração mecânica é a responsável pelo efeito clínico de rejuvenescimento sobre rugas profundas, a fibroplasia (ou neocolagenização é a responsável direta pelo resultado final da ação do laser sobre a pele com rugas superficiais, conferindo-lhe aparência mais jovem. O uso combinado dessas duas técnicas pode ser vantajoso, pois permite um resultado estético melhor com um único procedimento anestésico e cirúrgico em um curto período de recuperação. OBJETIVOS: O presente estudo morfométrico se propõe a avaliar se ocorre alguma alteração na espessura da fibroplasia induzida pelo resurfacing a laser erbium:YAG quando este se associa ao lifting cutâneo. MÉTODO: Foram utilizados 50 ratos da linhagem Wistar, divididos em dois grupos de 25, sendo que o primeiro grupo foi submetido à aplicação exclusiva de laser erbium:YAG no dorso de cada animal e o outro sofreu a aplicação de laser Erbium: YAG combinada ao lifting, o qual foi representado, no animal de experimentação, por retalho cutâneo dorsal pediculado. A fibroplasia foi avaliada nos dois grupos com medidas morfométricas lineares realizadas após o sacrifício dos animais nos dias 14, 28, 56, 84 e 112 do pós-operatório. RESULTADO: Foi observado aumento da fibroplasia em ambos os grupos estudados, porém o crescimento do colágeno foi superior no grupo submetido à terapia isolada com laser Erbium: YAG. CONCLUSÃO: A espessura da fibroplasia induzida pelo resurfacing a laser Erbium: YAG foi influenciada pela associação de um segundo procedimento cirúrgico no mesmo tempo operatório, neste caso, o lifting cutâneo.INTRODUCTION: The fibroplasia is the responsible for the final aesthetic results induced by laser resurfacing upon skin with superficial wrinkles. On the other hand, the lifting is responsible for the deeper wrinkles removal, produced by mechanic results. The use of the combination of these two rejuvenation

  13. Assessment of the bacteria reduction in the infected root canal irradiated with diode laser; Avaliacao da reducao bacteriana em conduto radicular infectado e irradiado com laser de diodo. Estudo in vitro

    Radaelli, Claudia Amaral Rabello de Mello


    High success rates are achieved in conventional endodontic treatment of vital pulp teeth. However, in cases of non-vital pulp, a decrease in the rate of success occurs due to difficulties in achieving a complete disinfection of the root canals system. Some bacteria, such as Enterococcus faecalis, are frequently found in cases of endodontic treatment failure due to their high resistance to the conventional endodontic treatment. The aim of this study was to evaluate the efficiency of a high power diode laser irradiation in bacterial reduction of contaminated canals associated with dressing compose by calcium hydroxide paste propylene glycol and camphorated paramonochlorophenol. Eighty-two root canals were infected in vitro with Enterococcus faecalis in a concentration of 1x10{sup 8} CFU/ml. Specimens were high intensity irradiated with a diode laser model Opus 10, at a wavelength of 830 nm. Two different parameters were employed in continuous mode: 3 W and 2,5 W with a 360 {mu}m optical fiber at an angle of approximately 5 degrees respect to the dentine surface during 5 seconds, in 4 applications, with 20 seconds intervals among them. After these proceedings specimens were vortexed in peptone water and dilutions performed. Aliquots of the dilution were plated on m-Enterococcus agar, incubated, and the Colonies Forming Units (CFU) of ali groups was counted. The results showed a significant reduction of bacteria on ali groups after laser irradiation. A high reduction rate was achieved: 98.5% immediately after the laser irradiation; 48 hours after, the reduction was of 96,73% and, finally, a 100% reduction was achieved through the combination of laser irradiation and a long lasting dressing of calcium hydroxide paste, propylene glycol and camphorated paramonochlorophenol. High rates of bacteria reduction were achieved using the parameter of 3 W in continuous mode with the power of 2,9473 KW/cm{sup 2}. The temperature was monitored with a K-pipe thermocouple placed at

  14. Histopathological study of the effects of low-intensity laser irradiation ({lambda}=650 nm) on dental pulp tissue after cavity preparation; Estudo histopatologico dos efeitos da irradiacao laser em baixa intensidade ({lambda}=650nm) em tecido pulpar apos preparo cavitario

    Bertella, Claudio


    The purpose of this study was to evaluate (in vivo) the effects of low-intensity Arsenide Gallium Aluminium laser application post-cavity preparation class 1. Six patients with bilateral pre-molars and molars indicated to extraction for orthodontics aim were selected. Four samples of these teeth underwent cavity preparation with deep from medium to high and two samples underwent cavity preparation from high to pulp expositions. The samples were constituted of two teeth of the same patient and received different treatments. One of the teeth underwent laser exposition and the other one was maintained as control, before restorative procedure with polycarboxylate cement. A diode laser ({lambda}=650 nm), output power 30 mW and fluencies of 1,8 J/cm{sup 2} and 2,7 J/cm{sup 2} in pre-molars and molars, respectively, was used for irradiation with repetition rate of 18 Hz in interrupted continuous wave mode. After seven days, the teeth were extracted and processed histologically with HE to verify morphological changes in the pulpy tissue. The four samples, which cavity preparation and restorative material were not in contact with the pulp, did not show histological differences between irradiated and non-irradiated teeth. Both of them presented the same characteristics of normality. The two samples with exposed pulpy tissue showed different results. The irradiated teeth presented no or slight inflammatory signs when compared to the control samples, which showed abscess in the coronary pulp interior and intense inflammatory infiltrated. These results suggest that the laser irradiation can be used as a therapeutic modality in clinical trials, in the conditions employed in this study. (author)

  15. Studies of the mechanisms involved in the laser surface hardening process of aluminum base alloys; Estudos dos mecanismos envolvidos em processos de endurecimento superficial a laser de ligas a base de aluminio

    Silva, Luciana Ventavele da


    The Al-Si alloys are widely used in industry to replace the steel and gray cast iron in high-tech sectors. The commercial importance of these alloys is mainly due to its low weight, excellent wear (abrasion) and corrosion resistance, high resistance at elevated temperatures, low coefficient of thermal expansion and lesser fuel consumption that provide considerable reduction of emission of pollutants. In this work, Al-Si alloy used in the automotive industry to manufacture pistons of internal combustion engines, was undergone to surface treatments using LASER remelting (Nd:YAG, {lambda} = 1.06 {mu}m, pulsed mode). The LASER enables various energy concentrations with accurate transfer to the material without physical contact. The intense energy transfer causes the occurrence of structural changes in the superficial layer of the material. Experiments with single pulses and trails were conducted under various conditions of LASER processing in order to analyze microstructural changes resulting from treatments and their effects on the hardness. For the characterization of hardened layer was utilized the following techniques: optical microscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), x-ray mapping, Vickers microhardness and maximum roughness tests. The high cooling rate caused a change in the alloy structure due to the refinement of the primary eutectic silicon particles, resulting in increase of the mechanical properties (hardness) of the Al-Si alloy. (author)

  16. Efeito do laser Nd:YAG no selamento de fóssulas e fissuras: estudo in vivo = Nd:yag laser effect on pit and fissures sealing: an in vivo study

    Firoozmand, Leily Macedo


    Full Text Available O objetivo desta pesquisa foi o de avaliar o comportamento clínico do laser Nd: YAG em comparação ao de um selante com carga, durante o período de 12 meses, observando; a pigmentação do sulco, incidência de cárie e fratura ou perda do selante. Foram selecionados 62 primeiros e segundos premolares hígidos de pacientes na faixa etária de 12 a 15 anos, de uma escola da rede pública de São José dos Campos. Nos 31 primeiros premolares foi aplicado o laser Nd: YAG, Pulse Máster 600 IQ em toda a extensão do sulco oclusal por 30 segundos utilizando 60 mJ, 10 HZ, 0,6W. Nos 31 segundos premolares foi realizado o selamento dos sulcos oclusais com o selante Fluorshield. Após 6 meses observou-se que dos casos selados com Fluorshield 19,35% apresentaram perda e/ou fratura do selante e em 16,66% os sulcos apresentaram cárie incipiente. Já nos casos em que foi aplicado o laser Nd: YAG 6,45% apresentaram início de lesão de cárie. Com 12 meses de avaliação tanto com selante Fluorshield como com o laser Nd: YAG observou-se o aparecimento de sulcos pigmentados em 12, 90% dos casos e uma incidência de 9,67% de lesões incipientes de cárie. Utilizando-se o selante Fluorshield houve queda do material em 25,80% e fratura em 3,22% dos casos. Concluímos que após 12 meses de avaliação o laser Nd: YAG e o selante Fluorshield apresentaram comportamento clínico semelhante, diante das mesmas condições bucais, sendo que a porcentagem de aparecimento de lesão inicial de cárie foi igual para os dois métodos de prevenção utilizados

  17. Phototherapy with low intensity laser in carrageenan-induced acute inflammatory process in mice paw - dosimetry studies; Fototerapia com laser em baixa intensidade em processo inflamatorio agudo induzido por carragenina em pata de camundongos - estudos de dosimetria

    Meneguzzo, Daiane Thais


    The importance of modulation of inflammation on the treatment of inflammatory diseases and the difficulty in determining the laser irradiation parameters has led us to study the effects of different protocols of phototherapy with low intensity laser (power, energy, time and place of irradiation) in the treatment and prevention of edema in acute inflammatory process using the experimental model of paw edema induced by carrageenan (CGN) in three strains of mice (Balb-c, Swiss and C57BL/6). The first stage of the study evaluated different combinations of energy (1J and 3J) with different powers (30, 60 and 100mW) in Balb-C mice paw irradiated 1 and 2h after injection of CGN. The second stage studied different combinations of location (foot, inguinal lymph nodes and both) and exposure time (2 and 1h before, 1h and immediately before the CGN, 1 and 2h and 3.5 and 4.5h after CGN) using fixed irradiation parameters (1J, 100mW, 35J/cm{sup 2}, spot area of 0.028 cm{sup 2}). The third stage compared different strains of mice Balb-c and C57BL/6) in the best local and time parameters found in step 2. At all stages, we evaluated the change in paw volume by plethysmography and inflammatory infiltrate by histomorphometry or analysis of myeloperoxidase (MPO). The results showed that laser phototherapy treated and prevented edema and modulated the inflammatory process with paw and inguinal lymph nodes irradiations accordingly with the parameters and mice strain used. (author)

  18. Effects of the infrared diode low intensity laser therapy for oral mucositis: a clinical trial; Estudo clinico dos efeitos do laser diodo de baixa intensidade de emissao infravermelha para casos de mucosite bucal

    Freire, Maria do Rosario Santos


    Chemotherapy associated or not with radiotherapy and surgery may be used for treating patients presenting some pathogenies such as cancer. Many side effects are visibly in the mouth in several forms as a consequence of this treatment and oral mucositis is the most common, with great prevalence, causing degrees of morbidity and even death. This research is about improving the quality of life for these patients by using of laser radiation through a GaAlAs active medium, in a continuous manner, with a low power ( 60 mW), the diode laser acting at 780 nm wavelength infrared, with a energy density 7,5 J/cm{sup 2} and 6,0 J/cm{sup 2}, for the therapeutic and preventive groups respectively, and a third control group without radiation. Two protocols were studied in patients during 5-fluorouracil chemotherapic regime and combinations, because nowadays polychemotherapy is used, an associations of drugs, for a neoadjuvant treatment, adjuvant, potentionalize or palliative means, for the chemotherapy treatment. In a context of 60 patients, 16 patients had received the laser irradiations doses, 10 days for the therapeutic protocols and 11 days for the preventive irradiations. The therapeutic group presented a 50% of the total healing process and significant decrease in symptoms of pain (VAS=0 with p =0,01). For the preventive irradiations (D-5, D, D+5), that means the day of the QT, 5 days before the chemotherapy regime starts until 5 days later, only 1 patient had some kind of ulceration during more than four months of control. Results of the present study showed to be effective and promising for both employed protocols, therapeutic and preventive. Further studies must be developed in order to improve the present results. (author)

  19. Estudo morfométrico e morfológico da cicatrização após uso do laser erbium: YAG em tecidos cutâneos de ratos Morphometrical and morphological study of cicatricial effects caused by application of laser erbium: YAG on the skin of rats

    Lúcia de Noronha


    Full Text Available Este trabalho analisa o efeito da reparação cutânea do laser erbium:yttrium aluminunn garnet (YAG (Er:YAG em pele de ratos através de estudo histológico e morfométrico. Tatuaram-se duas figuras no dorso de cada animal (n = 35, denominadas controle e experimento. Na figura experimento, aplicaram-se três passadas de laser Er:YAG com parâmetros padronizados. Cinco animais foram eutanasiados nos dias 0, 7, 14, 28, 56, 84 e 112 de pós-operatório. O estudo histológico demonstrou no dia 0 dano de ablação médio de 215,24 micrômetros (mm, sendo homogêneo com vaporização da epiderme e porções superficiais da derme. O dano térmico residual foi pequeno (média de 41,45mm, observando-se áreas onde estava praticamente ausente. A fibroplasia cicatricial já estava presente no dia 7 (média de 55,58mm, aumentando rapidamente até o dia 28 (média de 209,49mm, quando atingiu um platô e se manteve até o dia 112. Não houve sinais de processo inflamatório agudo no dia 7 e a reepitelização já estava completa. Concluiu-se que a aplicação de laser na pele de ratos induz reparação cutânea ao longo de 112 dias nas condições do experimento.This study analyses the skin contracture effect of the erbium:YAG (Er:YAG laser on the skin of rats by light microscopic histological and morphometrical evaluations. Two squares of back skin were precision tattooed on each of the animals (n = 35, that were termed control and experimental skin. The experimental skin was treated with three passes of the Er:YAG laser with standardized parameters. Five animals were killed and skin specimens were analyzed at 00, 07, 14, 28, 56, 84 and 112 days. Histologic examination demonstrated a mean of 215.24 micrometers ablative damage that was homogeneous with complete vaporization of the epidermis and superficial dermis. The residual thermal damage was small (mean of 41.45 micrometers observing areas where it was absent. The cicatritial fibroplasy was present at

  20. Irradiation of root cervical dentin by using the Nd:YAG laser in vitro study and scanning electron microscopy; Irradiacao de dentina cervical radicular com laser de Nd:YAG - estudo in vitro e microscopia eletronica de varredura

    Britto, Cynthia Tannure Coelho


    The dentin hypersensitivity occurs as a result of the dentine exposition to the oral environment, due to loss or removal of enamel or cementum, or both. The hypersensitivity can persist, unless the sealing of the dentin tubules be carried out. Several treatments have been considered, but with less satisfactory and only temporary results. Among these treatments we can cite methods that promote the mechanical occlusion by deposition of substances inside of tubules, by topic application. Nowadays, among the treatments studied, there is the use of lasers, which leads to better clinical efficiency by promoting fusion and re-solidification of the dentin surface, obliterating total or partially the dentin tubules. This in-vitro study was carried out in order to evaluate the efficiency of the Nd:YAG laser in promoting the fusion and re-solidification of the dentin surface, and to evaluate parameters of irradiation typically used, comparing results using photoinitiator with those without it. By observation of the dentin surface, using Scanning Electron Microscopy, it was found extensive areas of fusion and re-solidification, in those groups with photoinitiator, being this technique an efficient resource in the treatment of the dentin hypersensitivity. (author)

  1. Avaliação morfológica da união entre adesivo/resina composta e dentina irradiada com laser Er:YAG e laser Nd:YAG: estudo comparativo por microscopia de varredura Morphological evaluation of the bonding between adhesive/composite resin and dentin irradiated with Er:YAG and Nd:YAG lasers: comparative study using scanning microscopy

    Margareth ODA


    Full Text Available Desde a introdução de sistemas adesivos nos procedimentos restauradores com materiais estéticos, tem-se estudado de forma abrangente o tipo de tratamento na superfície dentinária para se consagrar uma técnica ideal. A utilização do ácido fosfórico a 37% sobre a dentina é atualmente ainda o método que mais se domina em termos de adesividade. Porém, métodos de tratamento alternativos, na dentina, têm sido discutidos na literatura, entre eles a aplicação de alguns tipos de irradiação a laser. O objetivo desta pesquisa foi avaliar morfologicamente a união adesivo/resina composta e dentina irradiada com laser Er:YAG e laser Nd:YAG num estudo comparativo por microscopia de varredura, utilizados em substituição ao condicionamento ácido ou associados ao mesmo. Foram utilizados dentes bovinos recém-extraídos, que receberam um preparo de cavidade de classe V, e restauração com sistema adesivo e resina composta fotoativada. Como variantes alguns deles receberam o tratamento prévio de irradiação com laser Er:YAG e outros de irradiação com laser Nd:YAG, à aplicação do agente adesivo e da resina composta. As amostras foram seccionadas, preparadas para microscopia de varredura e submetidas a uma análise morfológica, e foram feitos os registros por meio de fotomicrografias. Com base nessas observações microscópicas, concluímos que somente no tratamento da superfície da dentina com laser Er:YAG e condicionamento ácido houve penetração da resina na dentina. Nos tratamentos com laser Nd:YAG, houve apenas aparente superposição da resina na superfície dentinária, sugerindo que houve oclusão dos túbulos com características de fusão na dentina superficial.Since bonding systems were introduced in the restorative procedures carried out with esthetic materials, the treatment of dentin surfaces has been widely studied in order to establish the ideal technique. The application of 37% phosphoric acid on dentin is still

  2. An in vitro study of the Nd-YAG laser in the permeability of the cervical dentin; Estudo in vitro do uso do laser Nd-YAG na permeabilidade dentinaria cervical

    Magalhaes, Manoelita Figueiredo de


    The purpose of this in vitro study was to verify the efficacy of the Nd:YAG pulse laser, with 1064 nm emission, in sealing the dentinal tubules for the treatment of dentin hypersensitivity, a very frequent complaint in the dental office. In spite of the existence of many articles over this subject, no fast, efficient and long lasting treatments for this problem were found yet. The obliteration of the opening of the dentinal tubules stops its inner fluid displacement and the consequent painful response (BRAENNSTROEM' S Hydrodynamics Theory). Twenty freshly and healthy extracted human teeth were used as samples, kept in saline solution. The cervical cement was removed with a 57FG Carbide bur in order to expose the dentin in an area of approximately 4 mm{sup 2}, two of which were in the buccal aspect: Groups A and S, and one in the lingual: Group C (control). A thickness plier was used to measure, directly in each sample, the thickness of the remaining dentin that was standardized, and only the samples with dentinal thickness between 1 and 1,5 mm were selected. The irradiation parameters were: 30 mJ energy per pulse; O,21 W power (Group A) and 40 mJ; O,28 W (Group B); 7 Hz frequency in both groups, in two applications of 43 seconds each with a 10 seconds interval between them. Subsequently, 10 of the samples were submitted to SEM (Screening Electronic Microscopy) examination, where it was detected a melting of the superficial dentin and a sealing of the dentinal tubules opening, besides the recrystallization of the dentin. It was then concluded that the use of the Nd:YAG laser was shown to be a very effective measure in melting and sealing the dentinal tubules and can use in treating dentin hypersensitivity, with the right parameters. The other 10 samples were cleaved in the center of the irradiated area in order to investigate the laser penetration depth in the dentin (SEM), with an approximate variation of up to 5Jlm in the center of the samples irradiated with

  3. Removal of Dental Implants Using the Erbium,Chromium:Yttrium-Scandium-Gallium-Garnet Laser and the Conventional Trephine Bur: An in Vitro Comparative Study.

    Hajji, Mohammad; Franzen, Rene; Grümer, Stefan; Modabber, Ali; Nasher, Riman; Prescher, Andreas; Gutknecht, Norbert


    The purpose of this study was to compare the conventional trephine bur and the Erbium,chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser in removing implants in terms of the volume of removed bone, duration of the procedure, and morphological changes on the bone surface. Three human mandibles were utilized, and four implants were inserted in each mandible using a drilling handpiece and burs. The implants were divided into two groups (n = 6) in which two implants from each mandible were removed using a trephine bur running at 1200 rounds per minute (rpm) with water irrigation. The remaining implants (n = 6) were removed with Er,Cr:YSGG laser (power 6 W, frequency 20 Hz, pulse duration 50 μs, water 60, air 30). The volume of bone loss was calculated by filling the holes with mercury and measuring its volume. The preparation time was measured with a digital stopwatch and the postoperative bone surfaces were examined under a scanning electron microscope (SEM). The laser group exhibited a smaller amount of bone loss than the trephine bur group, whereas the latter required a shorter time of preparation. SEM revealed empty trabecular spaces with no signs of carbonization and well-defined edges in the laser group, whereas the trephine group displayed a surface covered with a smear layer and microcracks. The Er,Cr:YSGG laser provides superior results over the trephine bur in terms of bone preservation, thermal damage, and cutting efficiency.

  4. Estudo in vitro da microinfiltração marginal em cavidades submetidas ao tratamento com laser de Er:YAG e restauradas com materiais estéticos In vitro study of the microleakage in cavities submitted to treatment with Er:YAG laser and restored with aesthetic materials

    Margareth ODA


    Full Text Available O objetivo desse estudo foi avaliar, in vitro, a microinfiltração marginal em cavidades de classe V submetidas ao tratamento com laser de Er:YAG e restauradas com materiais estéticos. Foram selecionados 60 dentes humanos e realizados preparos de classe V no terço cervical das faces vestibular e lingual. A técnica restauradora seguiu as especificações dos fabricantes. Os dentes foram divididos em três grupos de 20 dentes: Grupo 1 (controle, Grupo 2: procedeu-se previamente à restauração um tratamento com laser de Er:YAG na superfície do esmalte do ângulo cavo-superficial, Grupo 3: antes da restauração, aplicou-se uma fina camada de cimento de Ca(OH2 na parede axial. Cada grupo foi dividido em quatro subgrupos e restaurados com materiais estéticos diferentes. Todos os dentes foram submetidos a ciclagem térmica e técnica de infiltração com nitrato de prata a 50%. Com base nos resultados, concluiu-se que existem diferenças entre as doze condições experimentais realizadas. As amostras que apresentaram maior microinfiltração foram, em primeiro lugar, as com tratamento com laser de Er:YAG e restauradas com cimento de ionômero de vidro fotoativado. Em segundo, as tratadas com laser de Er:YAG e restauradas com a técnica do sanduíche (cimento de ionômero de vidro convencional + resina composta fotoativada. Em terceiro, as restauradas com cimento de ionômero de vidro fotoativado, e por último as restauradas com a técnica do sanduíche.The aim of this in vitro study was to evaluate marginal microleakage in class V preparations submitted to treatment with Er:YAG laser and restored with aesthetic materials. Sixty human molars were selected and class V cavities were prepared on the buccal and lingual aspects of their cervical thirds. The restorative technique followed the instructions of the manufacturers. The samples were divided in 3 groups of 20 teeth each: Group 1 - control; Group 2 - Er:YAG laser was applied on the enamel

  5. Marginal microleakage in vitro study on class V cavities prepared with Er:YAG laser and etched with acid or etched with Er:YAG laser and acid; Estudo in vitro da microinfiltracao marginal em cavidades classe V preparadas com laser de Er:YAG e condicionadas com acido ou com laser de Er:YAG e acido

    Tavares, Henrique Dutra Simoes


    Microleakage at the interface between the teeth and the restorative materials remains a problem with composite resin restorations. Microleakage at the gingival margins of class V cavities restorations still challenge as they are usually placed in dentin and/or cementum. Previous studies have shown that the cavity preparation with Er:YAG laser is possible. It has been reported that Er:YAG laser has ability to create irregular surface providing micromechanical retention for adhesive dental restorative materials and to improve marginal sealing. The purpose of this in vitro study was to evaluate the marginal microleakage on class V cavities prepared with Er:YAG laser and etched with acid or with Er:YAG laser and acid, in compared to those prepared and etched conventionally. Thirty human molars were divided into three groups, namely: group I - prepared with Er:YAG laser (KaVo KEY Laser II - Germany) and etched with 37% phosphoric acid; group II - prepared with Er:YAG laser and etched with Er:YAG laser and 37% phosphoric acid; group III (control group) - prepared with high speed drill and etched with 37% phosphoric acid. All cavities were treated with same adhesive system (Single Bond - 3M) and restored with the composite resin (Z100 - 3M), according to the manufacturer's instructions. The specimens were stored at 37 deg C in water for 24 hours, polished with Sof-Lex discs (3M), thermally stressed, sealed with a nail polish coating except for the area of the restoration and 1 mm around it, and immersed in a 50% aqueous solution of silver nitrate for 24 hours. After that, the specimens were rinsed in water, soaked in a photodeveloping solution and exposed to a fluorescent light for 8 hours. The teeth were embedded in an autopolymerizing resin and sectioned longitudinally using a diamond saw microtome under running water. The sections were photographed. The microleakage at the occlusal cavity and at the gingival margins of each specimen was evaluated with scores (0

  6. Laser therapy in the management of dental and oro-facial trauma

    Darbar, Arun A.


    This is a clinical presentation demonstrating the efficacy of laser therapy in the treatment of patients presenting with trauma to both the hard and soft tissue in the orofacial region. The use of laser therapy aids the management of these cases where the patients often present with anxiety and a low pain threshold. The outcomes in these cases indicate good patient acceptance of the treatment, enhanced repair and tissue response suggesting that this form of treatment can be indicated for these patients. A combination of hard and soft lasers are used for the comprehensive dental management and treatment of these cases. The lasers used are a 810nm diode and an Er.CrYSGG.

  7. Estudo comparativo do uso de extrato de Pfaffia glomerata e do laser de baixa potência (Hélio-Neônio na cicatrização de feridas em ratos Comparative study of the use of Pfaffia glomerata and the low power laser (Helium-Neon in the healing of the wounds in rats

    Marileide Inácio da Silva Carneiro


    Full Text Available RACIONAL: A Pfaffia glomerata é planta utilizada na medicina popular como tônico, antidiabético, para melhorar o processo de cicatrização, neutralizar distúrbios gástricos e antirreumático. OBJETIVOS: Comparar a contração da ferida e a neovascularização com o uso da Pfaffia glomerata e do laser de baixa potência em dorso de ratos. MÉTODOS: Foram utilizados 40 ratos da linhagem Wistar nos quais realizaram-se feridas cirúrgicas com punch de 3 mm de diâmetro na parte superior direita do dorso onde nenhuma substância foi aplicada e nesses mesmos animais foram também realizadas feridas cirúrgicas no lado esquerdo na região inferior, onde foi aplicado o extrato das raízes de Pfaffia glomerata (Spreng. Pedersen, Amaranthaceae, obtendo-se desta maneira os grupos controle e planta nos mesmos animais. Em outros 40 animais, foi utilizado o laser de baixa potência. Nas datas programadas em 48 horas, uma, duas e três semanas foram tomadas as medidas da contração da ferida. Microscopicamente os resultados foram analisados utilizando-se imunoistoquímica como fator VIII para observar a densidade vascular. RESULTADOS: Macroscopicamente não houve diferença estatisticamente significante com relação à contração da ferida entre os grupos planta e laser, obtendo ambos resultados superiores ao grupo controle. Dentro desta variável, o resultado com diferença estatisticamente significante ocorreu dentro do grupo laser na comparação dos subgrupos: 48 horas vs. uma semana (p=0,008. A análise do Fator VIII mostrou significância estatística no subgrupo de uma semana da planta em relação ao laser(p=0,09. CONCLUSÕES: Não houve diferença estatisticamente significante com relação à contração da ferida entre os grupos planta e laser, obtendo ambos resultados superiores ao grupo controle no final do estudo; contudo, microscopicamente, o grupo planta obteve valor superior ao grupo laser quanto à neovascularização em uma semana

  8. Trombose em artérias pulmonares pequenas e médias em granulomatose de Wegener: um estudo com microscopia confocal por varredura a laser Thrombosis in small and medium-sized pulmonary arteries in Wegener's granulomatosis: a confocal laser scanning microscopy study

    Alfredo Nicodemos Cruz Santana


    Full Text Available OBJETIVO: A granulomatose de Wegener (GW pode causar dano nas células endoteliais e fenômenos tromboembólicos. Entretanto, poucos estudos analisaram a microcirculação pulmonar - artérias pulmonares de pequeno/médio calibre (APPMC - em pacientes com GW. O objetivo deste estudo foi quantificar trombos de fibrina em amostras de APPMC de pacientes com GW. MÉTODOS: Analisamos 24 APPMC de seis pacientes com GW e 16 APPMC de quatro pacientes controles sem WG. Utilizamos CD34 para a marcação do endotélio em todas as amostras e microscopia confocal a laser para detectar trombos de fibrina intravasculares. Calculamos a área total do vaso, a área livre do lúmen e a área trombótica. RESULTADOS: A média da área total do vaso foi similar no grupo GW e no grupo controle (32.604 µm² vs. 32.970 µm², p = 0,8793. Trombos foram identificados em 22 das 24 APPMC (91,67% no grupo GW, e em nenhuma do grupo controle (p OBJECTIVE: Wegener's granulomatosis (WG can cause endothelial cell damage and thromboembolic events. Nevertheless, there have been few studies on the pulmonary microcirculation-small and medium-sized pulmonary arteries (SMSPA-in patients with WG. The objective of this study was to quantify fibrin thrombi in the SMSPA of patients with WG. METHODS: We analyzed 24 SMSPA samples collected from six patients with WG and 16 SMSPA samples collected from four patients without WG. In all samples, we used the endothelial cell marker CD34 and confocal laser scanning microscopy in order to detect intravascular fibrin thrombi. We calculated the total vessel area, the free lumen area, and the thrombotic area. RESULTS: The mean total vessel area was similar in the WG and control groups (32,604 µm² vs. 32,970 µm², p = 0.8793. Thrombi were present in 22 (91.67% of the 24 WG group samples and in none of the control group samples (p < 0.0001; OR = 297; 95% CI: 13.34-6,612. The mean thrombotic area was greater in the WG group samples than in the

  9. um estudo de caso

    Costa, Cátia Filipa Pereira da


    Dissertação apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Psicologia Jurídica As situações de abuso sexual de crianças nas quais o perpetrador pertence ao sexo feminino obtiveram ao longo dos últimos anos um acrescido reconhecimento por parte da comunidade científica, evidenciado pelo significativo incremento das investigações no âmbito desta temática consistindo na sua maioria estudos de caso. Um conjunto de particularidades encont...

  10. Evaluation of Mechanical Properties of Glass Fiber Posts Subjected to Laser Surface Treatments.

    Barbosa Siqueira, Carolina; Spadini de Faria, Natália; Raucci-Neto, Walter; Colucci, Vivian; Alves Gomes, Erica


    The aim of this study was to evaluate the influence of laser irradiation on flexural strength, elastic modulus, and surface roughness and morphology of glass fiber posts (GFPs). Laser treatment of GFPs has been introduced to improve its adhesion properties. A total of 40 GFPs were divided into 4 groups according to the irradiation protocol: GC-no irradiation, GYAG-irradiation with erbium:yttrium-aluminum-garnet [Er:YAG], GCR-irradiation with erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG), and GDI-irradiation with diode laser. The GFP roughness and morphology were evaluated through laser confocal microscopy before and after surface treatment. Three-point bending flexural test measured flexural strength and elastic modulus. Data about elastic modulus and flexural strength were subjected to one-way ANOVA and Bonferroni test (p Laser treatment changed surface roughness in the groups GCR (p = 0.000) and GDI (p = 0.007). The mean flexural strength in GYAG (995.22 MPa) was similar to that in GC (980.48 MPa) (p = 1.000) but different from that in GCR (746.83 MPa) and that in GDI (691.34 MPa) (p = 0.000). No difference was found between the groups GCR and GDI (p = 0.86). For elastic modulus: GYAG (24.47 GPa) was similar to GC (25.92 GPa) (p = 1.000) but different from GCR (19.88 GPa) (p = 0.002) and GDI (17.20 GPa) (p = 0.000). The different types of lasers, especially Er,Cr:YSGG and 980 ηm diode, influenced the mechanical properties of GFPs.

  11. Comparison of the efficacy of different types of lasers for the treatment of peri-implantitis: a systematic review.

    Natto, Zuhair S; Aladmawy, Majdi; Levi, Paul A; Wang, Hom-Lay


    To evaluate the efficacy of various types of lasers (neodymium-doped yttrium-aluminum-garnet [Nd:YAG], carbon dioxide [CO2], diode, erbium/chromium-doped yttrium-scandium-gallium-garnet [Er,Cr:YSGG], and erbium-doped yttrium-aluminum-garnet [Er:YAG]) in the treatment of peri-implantitis and their use in surgical and nonsurgical procedures. Human studies for the treatment of peri-implantitis with laser therapy, published between 2002 and January 2014, were collected utilizing the electronic databases PubMed, Ovid, MEDLINE, Cochrane, and Google Scholar. Two reviewers conducted the study selection, data collection, and validity assessment. Eight hundred twelve studies were selected in the initial title search; 13 studies were then chosen for this review. No human studies evaluated the effect of the Nd:YAG laser on peri-implantitis. The CO2 laser is reported to be safe and able to enhance bone regeneration. The diode laser (980 nm) seems to be effective in its bactericidal effect without changing the implant surface pattern. The Er,Cr:YSGG laser was reported to obtain bone regeneration around a failing implant in one case, while the Er:YAG laser exhibits a strong bactericidal effect against periodontopathic bacteria at a low energy level. Although lasers have shown promising results in reducing clinical signs of peri-implantitis, because of the limited sample sizes and short follow-up periods, no firm conclusion can be drawn at this moment. Hence, there is a need for more well-designed, longitudinal, randomized controlled clinical trials.

  12. Avaliação das alterações do fluido crevicular gengival drenado de tecidos gengivais clinicamente normais submetidos à laser em baixa intensidade: estudo em anima nóbile

    Livio de Barros Silveira


    Nesta area da periodontia em que se situam os tecidos gengivais, a circulacao sanguinea periferica do periodonto e o liquido sulcular gengival (proveniente do sulco gengival) sao as duas importantes barreiras imunologicas que atuam na defesa dessa regiao, que e, por excelencia, a porta de entrada e instalacao da doenca periodontal. O presente estudo objetiva avaliar a utilizacao de uma conduta conservadora, nao invasiva, de ativacao da barreira imunologica contra a instalacao da doenca period...

  13. The effect of laser irradiation on retention of full cast crowns.

    Al-Omari, W M; Palamara, J E; Almohammed, S N


    The objective of this work was to determine the effect on the retention force of full cast crowns cemented on short tooth preparations after preparation of dentine with an erbium, chromium: yttrium scandium gallium garnet (Er, Cr:YSGG) laser at different sub-ablative power settings. Thirty teeth were prepared for full cast crowns using a milling machine. The surface area for all preparations was measured. The surfaces of the preparations were irradiated with 0 (control), 0.25 and 0.75 W laser. The crowns were cemented with self-cure resin cement and tested for retention on a Hounsfield Tensometer machine. The 0.75 W power setting produced the highest failure load value (346.2 +/- 86.1 N) and was significantly higher than the other groups. There were no significant differences between the 0.25 W and 0 W control groups

  14. Pancreatic capillary blood flow during caerulein-induced pancreatitis evaluated by a laser-doppler flowmeter in rats Estudo das alterações do fluxo capilar pancreático após infusão de ceruleína avaliado por laser-Doppler em ratos

    Roberto Ferreira Meirelles Jr.


    Full Text Available PURPOSE: The pancreatic capillary blood flow (PCBF was studied to determine its alterations during caerulein-induced pancreatitis in rats. METHODS: Twenty rats were divided in groups: control and caerulein. A laser-Doppler flowmeter to measure PCBF continuously was used. Blood pressure (BP and heart rate (HR were monitored. Serum biochemistry analyses were determined. Histopathological study was performed. RESULTS: The PCBF measured a mean of 109.08 ± 14.54% and 68.24 ± 10.47% in control group and caerulein group, respectively. Caerulein group had a mean decrease of 31.75 ± 16.79%. The serum amylase was 1323.70 ± 239.10U.I-1 and 2184.60 ± 700.46U.I-1 in control and caerulein groups, respectively. There was a significant difference in the PCBF (pOBJETIVO: O fluxo capilar pancreático (FCP foi estudado para determinar suas alterações durante a pancreatite aguda induzida por ceruleína, em ratos. MÉTODOS: Vinte ratos foram divididos em grupo controle e grupo ceruleína. Um laser-Doppler fluxímetro foi empregado para determinar, continuamente, o FCP durante 120 minutos. A pressão arterial média (PAM e a freqüência cardíaca (FC foram determinadas, durante o experimento. Análise bioquímica sérica e estudo histopatológico, por microscopia ótica, do tecido pancreático foram realizados, ao final do experimento. RESULTADOS: O FCP foi em média 109,08 ± 2,17% e 68,24 ± 16,79% nos grupos controle e ceruleína , respectivamente. No grupo ceruleína, houve uma diminuição média de 31,75 ± 16,79%. Os níveis de amilase sérica foram de 1323,70 ± 239,10U.I-1 e 2184,60 ± 700,46U.I-1 nos grupos controle e ceruleína, respectivamente. Houve diferença significante (p<0,05 no FCP e na amilasemia, quando comparado o grupo controle com o grupo ceruleína. Embora micro e macrovacuolização estivessem presentes no grupo ceruleína, não houve diferença histológica entre os grupos. CONCLUSÃO: A diminuição do FCP parece um evento precoce

  15. Investigations on laser hard tissue ablation under various environments

    Kang, H W [American Medical Systems-ICSV, San Jose, CA (United States); Oh, J [Division of Mechanical Engineering, Pukyong National University, Busan (Korea, Republic of); Welch, A J [Department of Biomedical Engineering, University of Texas at Austin, Austin, TX (United States)], E-mail:


    The purpose of this study was to investigate the effect of liquid environments upon laser bone ablation. A long-pulsed Er,Cr:YSGG laser was employed to ablate bovine bone tibia at various radiant exposures under dry, wet (using water or perfluorocarbon) and spray environmental conditions. Energy loss by the application of liquid during laser irradiation was evaluated, and ablation performance for all conditions was quantitatively measured by optical coherence tomography (OCT). Microscope images were also used to estimate thermal side effects in tissue after multiple-pulse ablation. Wet using water and spray conditions equally attenuated the 2.79 {mu}m wavelength laser beam. Higher transmission efficiency was obtained utilizing a layer of perfluorocarbon. Dry ablation exhibited severe carbonization due to excessive heat accumulation. Wet condition using water resulted in similar ablation volume to the dry case without carbonization. The perfluorocarbon layer produced the largest ablation volume but some carbonization due to the poor thermal conductivity. Spray induced clean cutting with slightly reduced efficiency. Liquid-assisted ablation provided significant beneficial effects such as augmented material removal and cooling/cleaning effects during laser osteotomy.

  16. Effect of Laser-Activated Irrigation on the Push-Out Bond Strength of ProRoot Mineral Trioxide Aggregate and Biodentine in Furcal Perforations.

    Nagas, Emre; Kucukkaya, Selen; Eymirli, Ayhan; Uyanik, Mehmet Ozgur; Cehreli, Zafer Cavit


    The objective of the present study was to assess the effect of erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser-activated irrigation (LAI) of NaOCl on the push-out bond strength of furcal perforations repaired with ProRoot mineral trioxide aggregate (MTA) and Biodentine. Several studies investigated the adhesion of calcium silicate-based cements after exposure to endodontic irrigants, while effect of LAI on bond strength remains to be elucidated. Bur-cut furcal perforations with standard dimensions were created in 100 extracted human mandibular molars. Teeth were randomly distributed into two groups (n = 50/group) according to the repair material applied: (1) ProRoot MTA or (2) Biodentine. The specimens were further assigned into five subgroups according to the irrigation regimens used over the set materials: (a) distilled water with needle irrigation; (b) 5.25% NaOCl with needle irrigation; (c) distilled water with LAI; (d) 5.25% NaOCl with LAI; and (e) no irrigation (control). Bond strengths of the test materials were assessed by using push-out bond strength test. Biodentine showed significantly higher dislocation resistance than ProRoot MTA (p  0.05). Biodentine showed higher dislocation resistance than ProRoot MTA as a perforation repair material. Er,Cr:YSGG laser activation of irrigation aqueous solutions had no adverse effect on push-out bond strength of Biodentine and ProRoot MTA.

  17. Estudo clínico e anatomopatológico da cicatrização cutânea no gato doméstico: utilização do laser de baixa potência GaAs (904 nm

    Angélica Cecília Tatarunas


    Full Text Available A pesquisa avalia a ação do laser de baixa potência Arseneto de Gálio (904 nm em feridas cirúrgicas de pele de felinos. Utilizamos 63 animais divididos em 3 grupos: A - radiados com 4J/cm2 , B - radiados com 2J/cm2 e C - controle, não radiados. A aplicação da radiação foi única no pós-operatório imediato em feridas cirúrgicas de gatas submetidas a ovariohisterectomia por conveniência. Realizamos estudo macroscópico e de microscopia de luz (Hematoxilina e Eosina nos tempos 2º, 4º, 8º e 15º dias de pós-operatório. Obtivemos clínica e microscopicamente resultados que sugerem um incremento na cicatrização das feridas radiadas quando comparado com o grupo controle e, se mostrando vantajosa ainda a radiação com 2J/cm2 em relação a 4J/cm2. Acreditamos, portanto ser o laser um adjuvante na cicatrização cutânea, podendo otimizar a evolução de feridas pós-cirúrgicas por primeira intenção nas condições e espécie animal estudada.This research evaluates the action of the Galium Arsenide laser (904 nm in feline cutaneous surgical wounds. We used 63 animals divided in 3 groups: A - radiated with 4J/cm2 , B - radiated with 2J/cm2 and C - control, not radiated. The aplication of the laser was accomplished in only one session in the immediate pos-operative procedures just after elective ovariohisterectomy. The macroscopical and microscopical analyses (Hematoxilin and Eosin of the skin were performed in 2, 4, 8 and 15 days pos-operatively. As result we obtained clinical and microscopical increase in the radiated wounds compared with control group and the energy densitie 2J/cm2 was more efficient than 4J/cm2 . Therefore we believe that the laser device can be used as coadjuvant in the healing process of skin wounds, in addition to optimizing the evolution of first intention post-surgery skin wounds in the studied species and circunstances.

  18. Estudo clínico-histológico da quelite actímica crônica tratada por dois protocolos de laser de CO2 de baixa morbidade

    Godoy Peres, Flávio Francisco de [UNIFESP


    Objetivo: Este ensaio clínico-histológico teve por meta avaliar a resposta terapêutica de dois protocolos de reconhecida baixa morbidade em passagem única. Métodos: Pacientes com queilite actínica crônica multicêntrica (n=40) comprovada pela microscopia foram randomicamente submetidos a dois protocolos de laser de CO2 pulsátil através de modelo comparativo bilateral (protocolo de pulsos de 350 mJ, 3,5 W, amplitude de 0,1s versus protocolo de pulsos de 250 mJ, 5 W, amplitude de 0,0...

  19. Estudo do tratamento do edema macular difuso do diabético com triancinolona intravítrea e fotocoagulação Use of intravitreal triamcinolone and laser photocoagulation for the treatment of diffuse diabetic macular edema

    Fábio Petersen Saraiva


    Full Text Available OBJETIVO: Avaliar a eficácia do uso intravítreo da triancinolona acetonida associada a fotocoagulação com laser no tratamento do edema macular difuso diabético. Comparar esta associação terapêutica com o uso isolado de cada tratamento. MÉTODOS: Após controle clínico sistêmico, trinta pacientes portadores de edema macular difuso diabético foram divididos em 3 grupos de tratamento: (1 fotocoagulação macular em grade com laser de argônio; (2 aplicação intravítrea de 4 mg de triancinolona acetonida; (3 associação dos itens anteriores. O seguimento foi realizado em intervalos predeterminados de um dia, uma semana e mensalmente, até completar 6 meses. Foram analisados os parâmetros: acuidade visual corrigida LogMAR, espessura macular central, volume macular total e pressão intra-ocular. RESULTADOS: A fotocoagulação com laser não reduziu de forma estatisticamente significativa a espessura macular central e o volume macular total. Esta redução foi significativa e estatisticamente semelhante nos outros dois grupos. Todos os grupos apresentaram melhora da acuidade visual, entretanto, o grupo que recebeu a associação do laser com a triancinolona intravítrea obteve maior porcentagem de pacientes com ganho de 10 ou mais letras de visão. CONCLUSÃO: O uso simultâneo da fotocoagulação com a triancinolona intravítrea pode ser considerado uma opção terapêutica para o edema macular difuso diabético.PURPOSE: To assess the efficacy of intravitreal use of triamcinolone acetonide combined with laser photocoagulation for the treatment of diffuse diabetic macular edema and to compare it with the separate use of each treatment. METHODS: After systemic clinical control, thirty patients with diffuse diabetic macular edema were divided into 3 treatment groups: (1 macular grid photocoagulation; (2 intravitreal injection of 4 mg of triamcinolone acetonide; (3 combination of the two previous therapies. Follow-up was scheduled at

  20. Estudo do efeito da dobutamina (Dobutrex) R e da radiação laser sobre a ação hidrosmotica da vasopressina em bexiga de sapo "in vitro"

    Wilson Franco


    Resumo: No presente trabalho é descrito e caracterizado o efeito de diversos agentes farmacológicos, em especial a Dobutamina e de um agente físico-radiação Laser - nos eventos que se seguem à interação da Vasopressina com os receptores da membrana de bexiga de sapo, e que são relacionados à síntese e inativação do 3'5'AMPc. O fluxo de água entre as duas faces da membrana foi medido gravimetricamente por meio da técnica de BENTLEY (1958) para preparações em formas de lobos e da técnica de PRO...

  1. A comparative study of the effect of low laser radiation on mast cells in inflammatory fibrous hyperplasia colored and not colored by the toluidine blue; Estudo comparativo do efeito da radiacao laser em baixa intensidade sobre mastocitos de hiperplasias fibrosas inflamatorias coradas e nao coradas por azul de toluidina

    Sawazaki, Iris



  2. In vitro study of 960 nm high power diode laser applications in dental enamel, aided by the presence of a photoinitiator dye: scanning electron microscopy analysis; Estudo in vitro das aplicacoes do laser de diodo de alta potencia 960 nm em esmalte dentario, assistido por um fotoiniciador: analise de microscopia eletronica de varredura

    Oliveira, Marcelo Vinicius de


    The objective of this study is to verify if a high power diode laser can effectively modify the morphology of an enamel surface, and if this can be done in a controlled fashion by changing the lasers parameters. Previous studies using SEM demonstrated that through irradiation with Nd:YAG laser (1064 nm) it is possible to modify the morphology of the dental surface in such way as to increase its resistance against caries decays. The desired procedures that should achieve a decrease of the index of caries decays and of its sequels are on a primary level, which means that action is necessary before the disease installs itself. In this study it was used for the first time a prototype of a high power diode laser operating at 960 nm, produced by the Laboratory of Development of Lasers of the Center for Lasers and Applications of the IPEN. This equipment can present several advantages as reliability, reduced size and low cost. The aim was establish parameters of laser irradiation that produce the desired effects wanted in the enamel and protocols that guarantee its safety during application in dental hard tissues, protecting it of heating effects such as fissures and carbonization. (author)

  3. In vitro studies of morphological changes in enamel surface after Er:YAG and Nd:YAG laser irradiation, by SEM; Estudo in vitro do efeito do laser Nd:YAG e Er:YAG sobre o esmalte dental humano atraves de microscopia eletronica de varredura

    Verlangieri, Eleonora Jaeger


    The caries prevention by using laser irradiation has been investigated by many authors using various lasers with different irradiations conditions. The purpose of this study was to investigated the morphological changes in enamel surface after Er:YAG and Nd:YAG laser irradiation, in vitro, by SEM. Fifteen freshly extracted, intact, caries-free, human third molars, were used in this study. The coronary portions were sectioned, from buccal to lingual direction, in two half-parts. Each one was irradiated by a different laser. The first one was irradiated with water-air spray, by a Nd:YAG laser, at 1.084 nm wave length, at 10 W, 10 Hz, 100 mJ for 60 sec., with an optical fiber in contact mode (0,32 mm of diameter); and the other half, with water-air spray by an Er:YAG laser at 2,94 micrometers wave length at the parameters of 4 Hz, 80 mJ, 24.95 J/cm{sup 2} for 60 sec. The results of this study suggested that both lasers promoted morphological changes in the enamel surface enhancing resistance and can be an alternative clinical method for caries preventions. (author)

  4. Effects of 960 nm diode laser irradiation on dental enamel in vitro: temperature and morphological analysis and evaluation of enamel demineralization; Estudo in vitro dos efeitos promovidos pelo laser de diodo em 960 nm no esmalte dental humano: analise de temperatura, analise morfologica e avaliacao da resistencia a desmineralizacao

    Kato, Ilka Tiemy


    The aim of this study is to determine the effects of diode laser irradiation on enamel demineralization. To achieve this goal appropriate photon absorbing substances for the laser radiation, safe laser parameters and adequate temperature measuring apparatus had to be determined. Next, the effects of diode laser and acidulated phosphate fluoride on enamel demineralization by calcium content analysis were evaluated with inductively coupled plasma atomic emission spectrometry (ICP-AES). In the first part of the study, five dyes consisting of vegetable coal diluted in five different liquids were analyzed and vegetable coal diluted in physiological solution was chosen for use as absorber. Methodologies to measure pulp chamber temperature were evaluated and modeling clay was chosen as fixture for the enamel samples held at body temperature. In the second part of the study, different energy density parameters (1.8 J/cm{sup 2}, 3.7 J/cm{sup 2}, 5.6 J/cm{sup 2}, 7.4 J/cm{sup 2} and 9.3 J/cm{sup 2}) exposure times (10, 15, 20, 25 e 30 seconds) and time intervals between dye application and laser irradiation (5, 30, 60, 90 e 120 seconds) were evaluated with respect to temperature changes in the pulp chamber. The enamel morphology was analyzed by scanning electron microscopy. Acid resistance was measured using seventy five enamel specimens, divided in five groups (control, fluoride, laser, laser + fluoride and fluoride + laser). The amount of calcium lost during demineralization in lactic acid was measured by ICP-AES. The results obtained in this experiment permit the conclusion that diode laser irradiation did not increase acid resistance. When associated with fluoride, the acid resistance did not differ from the results obtained with fluoride alone. (author)

  5. Evaluation of the efficacy of low-level laser therapy (LLLT and the microelectric neurostimulation (MENS in the treatment of myogenic temporomandibular disorders: a randomized clinical trial Avaliação da eficácia do laser de baixa freqüência e do neuroestímulo micro elétrico (MENS no tratamento das disfunções temporomandibulares miogênicas: um estudo clínico randomizado

    Evelyn Mikaela Kogawa


    Full Text Available OBJECTIVE: The aim of the present study was to evaluate the efficacy of low-level laser therapy (LLLT and the microelectric neurostimulation (MENS in the treatment of patients with temporomandibular disorders (TMD. MATERIAL AND METHODS: A sample of 19 individuals presenting with signs and symptoms of myogenic TMD was randomly divided into two groups (I - LLLT and II - MENS. Therapy was done in 10 sessions, three times a week, for one month. Patients were evaluated by the Visual Analogue Scale (VAS, measurement of active range of motion (AROM and muscle palpation, performed immediately before and 5 minutes after each therapeutic session by a blinded TMD specialist. The ANOVA for repeated measurements and Mann-Whitney tests were used for the statistical analysis. RESULTS: The results showed an increase in maximum mouth opening and a decrease in tenderness to palpation for both groups. The VAS reduced for both groups, although more evident for the laser group (pOBJETIVO: Avaliar a efetividade do laser de baixa freqüência e do estímulo muscular microelétrico (MENS no tratamento de pacientes com disfunções temporomandibulares (DTM. MATERIAL E MÉTODOS: Uma amostra de 19 indivíduos com sinais e sintomas de DTM de origem muscular, foi dividida em dois grupos (I -laser e II - MENS. O tratamento consistiu de 10 sessões, três vezes por semana, durante um mês. Os critérios de avaliação dos pacientes foram: escala de análise visual (EAV, mensuração de abertura máxima bucal e palpação muscular, estes foram avaliados imediatamente antes e 5 minutos após cada sessão terapêutica, num estudo do tipo controlado. Para análise estatística, foram aplicados ANOVA para mensurações repetidas e Mann-Whitney. RESULTADOS: Os resultados demonstraram aumento da abertura bucal máxima e diminuição na sensibilidade à palpação em ambos os grupos e, em relação à EAV, ambos os grupos demonstraram decréscimo, mas houve uma diferen

  6. Study in vitro of dental enamel irradiated with a high power diode laser operating at 960 nm: morphological analysis of post-irradiation dental surface and thermal effect analysis in pulp chamber due to laser application; Estudo in vitro do esmalte dental irradiado com laser de diodo de alta potencia em 960 nm: analise morfologica da superficie dental pos-irradiada e analise do comportamento termico na camara pulpar devido a aplicacao laser

    Quinto Junior, Jose


    Objectives: This study examines the structural and thermal modifications induced in dental enamel under dye assisted diode laser irradiation. The aim of this study is to verify if this laser-assisted treatment is capable to modify the enamel surface by causing fusion of the enamel surface layer. At the same time, the pulpal temperature rise must be kept low enough in order not to cause pulpar necrosis. To achieve this target, it is necessary to determine suitable laser parameters. As is known, fusion of the enamel surface followed by re-solidification produce a more acid resistant layer. This surface treatment is being researched as a new method for caries prevention. Method and Materials: A series of fourteen identically prepared enamel samples of human teeth were irradiated with a high power diode laser operating at 960 nm and using fiber delivery. Prior to irradiation, a fine layer of cromophorous ink was applied to the enamel surface. In the first part of the experiment the best parameter for pulse duration was determined. In the second part of the experimental phase the same energy density was used but with different repetition rates. During irradiation we monitored the temperature rise in the pulpal cavity. The morphology of the treated samples was analysed under SEM. Results: The morphology of the treated samples showed a homogeneously re-solidified enamel layer. The results of the temperature analysis showed a decrease of the pulpal temperature rise with decreasing repetition rate. Conclusion: With the diode laser it is possible to cause morphological alterations of the enamel surface, which is known to increase the enamel resistance against acid attack, and still maintain the temperature rise in the pulpar chamber below damage threshold. (author)

  7. Laser-assisted cavity preparation and adhesion to erbium-lased tooth structure: part 1. Laser-assisted cavity preparation.

    De Moor, Roeland Jozef Gentil; Delmé, Katleen Ilse Maria


    The use of the ruby laser (693.4 nm) was first described in 1960, and it was applied for hard tissue ablation in 1964. Different wavelengths [Nd:YAG (1.065 microm), CO2 (9.6 microm), Ho:YAG (2.12 microm)] were consequently explored. Due to massive thermal side effects, these wavelengths caused increased temperature in dental pulp, as well as microcracks and carbonization. The use of this laser for dental hard tissue preparation was eventually abandoned. At the end of the 1980s, excimer lasers (ultraviolet) and the erbium laser (infrared) were developed, with the advantages of improved temperature control and smaller penetration depths. With the development of smaller devices and improved knowledge of how to limit damage to the surrounding tissues, new ablation techniques were established in the 1990s. There is still contradiction in the current literature, however, in that different wavelengths are advocated for hard tissue removal, and heterogeneity in laser parameters and power densities remain. In this review, the effects of the wavelengths presently used for cavity preparation are evaluated. We conclude that erbium lasers (Er:YAG and Er,Cr:YSGG) are most efficient and, with the right parameters, the thermal side effects are small. There is a substantial need for "gold standards", although this is difficult to establish in practice owing to different laser parameters (including pulse repetition rate, amount of cooling, energy delivered per pulse, and types of pulses) and target specificity (tissue interaction with sound or decayed enamel or dentin, and the extent of (de)mineralization) which influence tissue interaction.

  8. Minimally invasive treatment of carious dentin with a nanosecond pulsed laser at 5.8 μm wavelength

    Ishii, Katsunori; Saiki, Masayuki; Yoshikawa, Kazushi; Yasuo, Kenzo; Yamamoto, Kazuyo; Awazu, Kunio


    Conventional lasers, Er:YAG laser and Er,Cr:YSGG laser, lack the ability for selective excavation to discriminate carious tissue only because they use the laser tissue interaction derived from a strong absorption of water. Based on the absorption property of carious dentin, characteristic absorption bands around 6 μm are candidate for selective excavation. Our group has already observed the difference of ablation depth between demineralized and normal dentin in the wavelength range from 5.75 to 6.60 μm. Also this study has showed the effectiveness of 5.8 μm. Objective of this study is to determine optimal irradiation parameters of selective excavation by using 5.8 μm. Bovine dentin plates demineralized by soaking in lactic acid solution were used as a carious dentin model. A nanosecond pulsed laser at 5.8 μm wavelength was obtained by difference-frequency generation technique. The laser delivers 5 ns pulse width at a repetition rate of 10 Hz. After irradiation, morphological change and measurement of ablation depth was observed with a scanning electron microscope and a confocal laser microscope, respectively. In 5.8 μm wavelength, high ablation efficiency with a low thermal side effect was observed. 5.8 μm wavelength provides a selective excavation technique for minimal intervention.

  9. Clinical comparative study between the use of lasers and conventional methods of diagnosis and treatment in deciduous teeth with presence of carious lesion; Estudo clinico comparativo entre o uso de lasers e metodos convencionais de diagnostico e tratamento em dentes deciduos da presenca de lesao cariosa

    Pulga, Fabiane Galvao


    The aim of this work was to evaluate the efficiency of deciduous tooth cavity preparation by the Er:YAG laser in comparison with the conventional burr rotary instrument. Besides, we have used the laser fluorescence technique (DIAGNOdent equipment) for diagnosis and compared it to the usual tactile and visual examination as well as X-ray diagnosis. For this purpose, 20 chronic occlusal carious deciduous molar teeth from children with the ages between 5 to 10 years old were selected. Selection was ma de according to visual inspection, X-ray periapical image and measures of the DIAGNOdent. For treatment the teeth were divided in two groups, 10 to be treated by the Er:YAG laser and 10 with conventional burr. For enamel, the laser energy used was in the interval from 200 to 300 mJ; for the dentine the range was from 100 mJ to 200 mJ. In both cases, the laser frequency was in the range from 2 to 4 Hz. The results have shown that the laser treatment was more accepted by the children than the conventional burro Clinical evaluation of the cavity preparation indicates that the Er:YAG laser treatment is recommend. The DIAGNOdent evaluation method was very effective for diagnosis of carious tissue for initial detection. After successful removal of the carious tissue, confirmed by visual inspection, the DIAGNOdent evaluation method was only effective for the treatment with conventional burro For evaluation of the tooth after cavity preparation with the Er:YAG laser, the measurements oscillate covering the full range of the equipment. Therefore, the use of the DIAGNOdent equipment is indicated only for initial caries diagnosis. (author)

  10. A study in vitro on radiation effects by Er:YAG laser combined with the fluorine therapy in the acid resistance of the dental enamel submitted to orthodontical brackets; Um estudo in vitro sobre os efeitos da irradiacao pelo laser de Er:YAG combinado com a terapia com fluor na resistencia acida do esmalte de dentes submetidos a aparelho ortodontico fixo

    Yoshiyasu, Roseli Y.A


    Several researches have been demonstrating an increase in the resistance acid of the enamel surface when irradiated by some lasers types as Nd:YAG, C0{sub 2}, Er:YAG, and others, mainly when combined with the fluoride therapy after the irradiation of the laser. This study in vitro used the laser of Er:YAG which density of energy of 8.1 J/cm{sup 2} on the enamel about of orthodontical brackets of teeth extracted pre-molars. These teeth were then submitted to a rich way in S. mutans for twenty one days. The cases were analyzed: (1) enamel surface without any treatment, (2) enamel surface without any irradiation laser, but with therapy with acidulated phosphate fluoride, (3) enamel surface irradiated with laser of Er:YAG and (4) enamel surface irradiated by laser of Er:YAG and with application of acidulated phosphate fluoride. The results were analyzed through optical microscopy and scanning electron microscopy. The morphologic changes observed to the scanning electron microscopy suggest increase in the acid resistance of the enamel surface. However, to the optical microscopy, it was still possible to visualize undesirable white stains in the surface of the enamel. (author)

  11. Nd:YAG laser irradiation on temporary teeth carious tissue using 12% diamine silver fluoride as a photo-absorber - a morphological study; Estudo comparativo morfologico da acao do laser de Nd:YAG em dentina cariada de dentes deciduos in vitro, condicionados com diamino fluoreto de prata a 12% e carvao mineral

    Calmon, Andrea de Avillez


    Since Nd:YAG laser radiation was first introduced in Dentistry various photo-absorbers were employed with the intent of improving its efficacy when used on dental carious tissue. The purpose of the present study was to analyze the influence of this radiation using Scanning and Optical microscopy over carious tissue of primary teeth using two photo-absorbers. 15 primary human teeth were used and, in each one, 3 cavity preparations were performed. Specimens were then submitted to an in vitro demineralizing environment during 18 days. Two of the cavities of each specimen were laser irradiated using the Nd:YAG laser with 60 mJ of energy per pulse, 10 Hz and average power of 0,6 W. The 12% diamine silver fluoride or the mineral coal were used as photo-absorbers. The third cavity of the specimens was used as a control and received no laser irradiation. Samples were transversally cut and the section analyzed by SEM and OM. Results showed that the 12% diamine silver fluoride is an efficient photo-absorber and, when used it the Nd:YAG laser, leading to melting and resolidification of the carious tissue. It can be concluded that the 12% diammine silver fluoride presents advantages over the mineral coal as a photo absorber when used in primary teeth as it promotes and improves the efficacy of laser irradiation. This substance also works as a barrier on the carie progression in deeper areas such as the infected and necrotic zones. (author)

  12. Estudo sobre o potencial da terapia a laser de baixa potÃncia (lllt) na periodontite apical: AvaliaÃÃo histolÃgica da influÃncia da LLLT na evoluÃÃo do processo inflamatÃrio periacapical induzido, e no seu uso como terapia adjuvante ao tratamento convencional, no modelo experimental da periodontite em ratos

    OtÃvio Henrique Pinhata Baptista


    A periodontite apical, muito freqÃente como seqÃela da cÃrie dentÃria, ainda à considerada como um processo patolÃgico de difÃcil controle e resoluÃÃo, tendo o sistema imunolÃgico como o principal fator de desenvolvimento e perpetuaÃÃo da mesma. A terapia a laser de baixa potÃncia (LLLT) jà vem sendo estudada como mÃtodo terapÃutico em vÃrias Ãreas da Odontologia, porÃm seu mecanismo de aÃÃo e conseqÃentes efeitos sobre as periodontites apicais nÃo sÃo ainda bem compreendidos. Esse estudo tev...

  13. Análise direcional do fluxo sangüíneo miocárdico após revascularização transmiocárdica com laser de CO2: estudo através da ressonância magnética com imagens de gradiente ultra-rápido

    DALLAN Luís A.


    Full Text Available OBJETIVO: Avaliar a direção do fluxo sangüíneo miocárdico de pacientes submetidos à revascularização transmiocárdica com laser de CO2 (RTML, através de estudos de imagem por ressonância magnética. CASUÍSTICA E MÉTODOS: Dez pacientes submetidos a RTML com laser de CO2 (potência de 800 W foram estudados através da ressonância magnética de gradiente ultra-rápido (Gradiente eco-EPI de seqüência híbrida, visando avaliar o direcionamento da perfusão miocárdica após o procedimento. Gadolínio - DTPA (0,1 mmol/kg foi injetado "em bolus" através de veia periférica em velocidade de 5 ml/seg em repouso durante o pico de "stress" induzido por dipiridamol. Foi avaliada sua distribuição miocárdica através da obtenção de curvas de intensidade de sinal no tempo para as diversas sub-regiões do miocárdio, em modelo de 24 segmentos. RESULTADOS: Após período médio de 14,7 meses, pudemos detectar isquemia em ao menos uma das paredes ventriculares em 6 (60% pacientes. Em 1 (10% paciente pode-se notar que o fluxo sangüíneo miocárdico dirigia-se do subendocárdio para o subepicárdio, ao contrário dos demais. CONCLUSÃO: A ressonância magnética, usando a técnica de perfusão miocárdica de primeira passagem, permitiu observar o direcionamento do fluxo sangüíneo miocárdico. Em um dos pacientes, a presença de fluxo miocárdico invertido (do endocárdio para o epicárdio sugeriu a patência dos canais realizados através da RTML.

  14. Bone repair of the periapical lesions treated or not with low intensity laser ({lambda} = 904 nm).(An X-ray study in human); Reparacao ossea de lesoes perirradiculares tratadas ou nao com lasers em baixa intensidade ({lambda}=904 nm). Estudo radiografico em humanos

    Sousa, Gerdal Roberto de


    The purpose of this study was to evaluate the influence of low intensity laser on the bone repair over periapical lesions of dental elements. Fifteen patients with a total of eighteen periapical lesions were selected and divided into two groups. Lesions of the control group were submitted to endodontic treatment and/or periapical surgery and the lesions of the experimental laser group, were submitted to the same procedures of the first group but also irradiated by low intensity laser. It was used a 904 nm wavelength laser GaAs, employing 11 mW of power delivered by a fiber optic system, irradiation continuos and contact mode, using a fluency of 9 J/cm{sup 2}. The mentioned treatment was repeated for 10 sessions with intervals of 72 hours between each session. Bone repair was evaluated through lesion measurements, which were accessed from the X ray pictures using a time and then, were also statistically analyzed. Results showed a significant difference between lased and control groups (p<0,10), emphasizing that for the laser group presented a significant reduction of the lesions area, confirmed by X ray. (author)

  15. Estudo multicasos sobre atividades inovativas

    Sonia Regina Hierro Parolin


    Full Text Available Em estudos sobre competitividade argumenta-se que as empresas necessitam de estratégias baseadas em inovações e de capacidades internas em constantes e intensas transformações, não somente nos padrões tecnológicos, mas também no encadeamento do processo de gestão das atividades inovativas, como processos dinâmicos, não lineares e diversificados, em função de múltiplos fatores dos ambientes interno e externo. Para contribuir com essas discussões, neste artigo apresenta-se um estudo multicasos em quatro indústrias de médio e grande portes, de segmentos, densidades tecnológicas e históricos com inovações diferentes entre si. Como principais resultados, salientam-se o encadeamento das atividades inovativas como parte de uma estratégia organizacional para obter resultados com inovação e a afluência de todas as pessoas, e não somente as alocadas em pesquisa e desenvolvimento, para o cumprimento dessa estratégia.

  16. Study and characterization of ceramic materials from natural origin for application in jewellery design using laser texturing as innovation; Estudo e caracterizacao de materiais ceramicos de origem natural para aplicacao no design de joias utilizando a texturizacao a laser como diferencial de inovacao

    Elesbao, T.R.; Carus, L.A.; Tabarelli, A.C.; Vieira, R.P.; Takimi, A.S., E-mail: [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Departamento de Materiais


    Technological development has been largely responsible for changes in the jewelry market. Seeking to contribute to the development of new products, this study analyzed the technique of laser texturing, aiming to add commercial and aesthetic values to the mother of pearl, material used in the jewelry field. The methodology was divided into physico-chemical characterization of the mother-of-pearl and of the resulting residue of laser texturing and analysis of the interaction of laser with the surface of the mother-of-pearl. The characterizations carried out were: Infrared spectroscopy, X-ray diffraction, thermogravimetric analysis and scanning electron microscopy. Results indicate that the studied material is composed mainly by the aragonite crystal phase, different from that resulting residue from texturing process. Although the process remove some of the gem material, the effect water characteristic of the mother-of-pearl is maintained, suggesting that technology combined with research and design can increase the value of this material. (author)

  17. Evaluation of temperature variation in pulp chamber after high power diode laser irradiation ({lambda}=830 nm) on dental enamel: 'in vitro' study; Avaliacao da variacao da temperatura na camara pulpar apos a irradiacao de diodo laser de alta potencia de 830 nanometros em esmalte dental: estudo 'in vitro'

    Macri, Rodrigo Teixeira


    The aim of this study was to observe the variation of temperature in the pulp chamber caused by irradiation of a commercial diode laser operating in continuous wave with wavelength 830 nm over the dental enamel. In the first part of this study, two types of tooth models were tested: 3,5 mm slice and whole tooth. In the second part, we irradiated the buccal si de of the enamel in 2 primary lower incisors from cattle with Opus 10 diode laser for 10 s with power levels of 1 W and 2 W, always using an absorber. Two thermocouples were used. The first one was inserted in the dentin wall closest to the irradiation site, while the second was inserted in the middle of the pulp chamber. It was observed that the thermocouples registered different temperatures. Always, the dentin thermocouple registered higher temperatures. Considering the dentin records, the irradiation of 1 W for 10 s can be safe for the pulp. Further studies must be developed related to the correct positioning of the thermocouples inside the pulp chamber. This was a first step of using diode laser in enamel, and in this study, we concluded that the Opus 10 diode laser shown to be safe for this use, with 1 W power for 10 S. (author)

  18. In vitro comparative study of share bond of light cured composite resins with halogen light and argon laser, using stainless steel brackets on human premolars; Estudo comparativo in vitro da capacidade adesiva da resina fotoativada pela luz halogena e por laser de argonio, utilizando-se brackets metalicos em pre-molares humanos

    Carillo, Vitoria Eugenia Bismarck


    The aim of this study in vitro was to compare the share bond strength of the light-cured composite resins Transbond XT (Unitek), with halogen light and argon laser. The Adhesive Remmant Index (ARI) was also investigated. The brackets Dyna lock (3M-UNITEK) were bonded to 75 human premolars, divided into 5 groups (15 each) according to time and the polymerization: Group H20, 15 brackets bonded with halogen light for 20s (10s both sides); Group H40, 15 brackets bonded with halogen light for 40s (20s both sides); Group A40, 15 brackets bonded with argon laser for 40s (20s both sides); Group A20, 15 brackets bonded with argon laser for 20s (10s both sides); Group A10, 15 brackets bonded with argon laser for 10s (5s both sides). The pulpal temperature changes were determined during a polymerization, not exceeding 3,5 deg C. After bonding, the teeth were submitted to a thermo cycled of 700 cycles between 5 deg C and 55 deg C, to simulate the consuming that the light cured composite resin would have in a short space of time. The specimens were then placed in PVC ring and embedded in acrylic resin (Aero-Jet). The tensile bond strength test was performed on an Universal Machine set at a crosshead speed of 1,5 mm/min, and for each rupture we registered a graphic and the best load required in Newtons, was converted to MPa and kgf. The share bond strength showed bigger values for the exposure time of 20 seconds, for the Group bonded for halogen light (H20), 7,45 kgf (7,64 MPa) and for argon laser 7,50 kgf (7,69 MPa); lesser values for the exposure time of 40s for the Group with halogen light (H40), 6,15 kgf (6,30 MPa) and argon laser Group (A40), 6,20 kgf (6,35 MPa) 0; and A10, 4,85 kgf (4,97 MPa). In the ARI Index, only A40 Group showed the 1 Index, with statistical results. In this Group, less than half of the remainder adhesive stayed on the surface of the enamel, conferring specimens failed at the enamel-adhesive interface. The results of the in vitro study demonstrate that

  19. Estudo comparativo histológico na prega vocal após incisão com instrumental a frio e com laser de CO2 em modelo animal Comparative histology study of the vocal folds after incision with cold instruments and CO2 laser in an animal model

    Fernando C. C. Santos


    Full Text Available Dentre os vários tipos de laser usados em Medicina, o laser de CO2 é o mais usado na Otorrinolaringologia e Cirurgia de Cabeça e Pescoço. As vantagens de seu uso são a diminuição do sangramento, a diminuição do edema no pós-operatório e a facilidade de acesso ao campo operatório, entre outras. Desde os trabalhos de Jako e Strong em 1972(1,2, quando o laser de CO2 passou a ser usado no tratamento de papilomatose laríngea e de lesões malignas glóticas iniciais, suas indicações têm aumetado, principalmente em lesões benignas, a partir da alta tecnologia desenvolvida dos últimos anos como, por exemplo, a diminuição do microspot e o uso do superpulso, reduzindo conseqüentemente seu efeito térmico sobre os tecidos. MÉTODOS: Neste trabalho foram realizadas incisões com instrumental a frio e com laser de CO2 1 watt de modo contínuo e superpulso, em pregas vocais caninas e observado, através de cortes histológicos corados pelo método de Sirius Red, a quantidade de colágeno depositada sobre as mesmas. RESULTADOS: A quantidade de colágeno das pregas vocais foi maior do que no grupo controle, e estatisticamente maior no grupo de animais submetidos a procedimentos com instrumental a frio do que com laser de CO2. Não houve diferença estatística entre o grupo controle e o grupo submetido a incisões com instrumentos a frio. CONCLUSÃO: A microcirurgia de laringe com o laser de CO2, quando este é usado em baixa potência, com pequeno "microspot" e com superpulso, é um método seguro em relação à deposição de colágeno, quando comparado com instrumentos com lâmina a frio, obedecendo os princípios da fonomicrocirurgia.Among the several types of lasers employed in medicine today, the CO2 is the most widely used in otorhinolaryngology and head and neck surgeries. The advantages of its use are: the reduction in bleeding, reduction in post-operative edema and the easy access to the operation site, among others. Ever since

  20. [Cavity preparation using an Er:YAG laser in the adult dentition].

    Delmé, K; Meire, M; De Bruyne, M; Nammour, S; De Moor, R


    Many lasers (i.e., different wavelengths) are available today for clinical applications. Not all lasers are to be used for cavity preparation and removal of carious tissues. Erbiumlasers (Er:YAG and Er,Cr:YSGG) are suitable for these purposes (the wavelengths coincide with the highest absorption peaks of water and hydroxyapatite). The advantages during cavity preparation and caries removal are smear layer free cavity walls, selective and localised removal of tooth substance, a restricted need or the absence of anaesthesia, and cavity walls with a higher acid resistance resulting in a better protection against secondary decay. Possible side effects of erbium lasers with water cooling and used with respect for correct power setting are minimal and can be compared with those of rotary instruments. Erbium laser tooth preparation is now one of the options in the minimal invasive approach. The needs for acid etching has been debated for long. At present it has become clear that acid etching is mandatory to obtain a good adhesion and retention with resin composites.

  1. Sealing of silorane-based composite in laser-prepared primary teeth: effect of acid etching.

    Shafiei, Fereshteh; Memarpour, Mahtab; Fekrazad, Reza


    The purpose of this study was to evaluate the influence of prior etching on the sealing of silorane composite restorations in Class V cavity preparations prepared with an Er,Cr:YSGG laser compared to bur preparation in primary teeth. Standard Class V cavity preparations were prepared on the buccal surfaces of 56 extracted primary canines and randomly divided into four groups of 14 teeth each, according to laser or bur preparation and the use of prior acid etching in the preparation. All cavity preparations were restored with silorane adhesive and silorane composite. After water storage and thermocycling, the specimens were placed in 0.5 percent basic fuchsin dye solution. Dye penetration was evaluated with a stereomicroscope. The data were analyzed with nonparametric tests (P=.05). Laser preparation and prior etching in bur-prepared cavity preparation had no significant effect on enamel sealing (P>.05), but significantly increased microleakage at the dentin margin (Pacid etching may be necessary to ensure good marginal sealing when laser preparation is used. However, this step is not required when bur cutting is used in primary teeth.

  2. High performance of a passively Q-switched mid-infrared laser with Bisub>2sub>Tesub>3sub>/graphene composite SA.

    You, Zhenyu; Sun, Yijian; Sun, Dunlu; Zhu, Zaojie; Wang, Yan; Li, Jianfu; Tu, Chaoyang; Xu, Jinlong


    We report passively Q-switched ∼2 and ∼3  μm mid-infrared (MIR) solid-state lasers with a self-assembly solvothermal-synthesized Bisub>2sub>Tesub>3sub>/graphene heterostructure saturable absorber (SA) for the first time. Based on the oxidation resistance and high thermal conductivity of graphene, and large modulation depth of Bisub>2sub>Tesub>3sub> nanosheets, two high-performance Q-switching lasers were realized. One is a Tm:YAP laser with a maximum average output power of 2.34 W and a pulse width of 238 ns at ∼2  μm. The corresponding maximum pulse peak power was 91 W, which was much improved in comparison with the pure graphene-based Tm laser. The other one is an Er:YSGG laser producing a pulse width of 243 ns, which is the shortest among the 2D SAs-based ∼3  μm solid-state lasers, as far as we know. Our results indicate that such a composite Bisub>2sub>Tesub>3sub>/graphene material is a promising SA for generating high-performance mid-infrared pulse lasers.

  3. Effects of low-energy laser irradiation on the distalization velocity during experimental canine tooth movement in humans: 'comparative clinical study'; Efeitos da irradiacao com laser em baixa intensidade na velocidade de distalizacao de caninos durante a movimentacao ortodontica: 'estudo clinico comparativo'

    Cruz, Delma Rebelo


    This research investigated the effects of low level laser therapy (LLLT) upon the velocity of canine tooth movement and consequently bone remodeling. A total of eleven patients were treated with a 780 nm diode laser. One side of the upper arcade was considered control group and was not irradiated but received mechanical activation every thirty days. The opposite side received the same mechanical activation but was also irradiated at days 0, 3, 7 and 14 of each month. Data of the biometrical progress were taken on both sides on days 3,7,14,21 and 30 of each month. The results indicate that all patients showed significant acceleration of the distalization velocity on the side treated with LLLT when compared to the control. (author)

  4. Mast cells behavior analysis: non mineralized wall of suprabony periodontal pockets submitted to low intensity laser radiation. (An in anima nobile study); Verificacao do comportamento de mastocitos na parede nao mineralizada da bolsa periodontal supra-ossea submetida a radiacao laser de baixa intensidade. (Estudo in anima nobile)

    Silveira, Livio de Barros


    For this study 20 patients with periodontal disease were selected. The treatment required for all of then was the gingivectomy, a ressective periodontal surgery. This technique consists of removing the whole excess of gingival tissue with the intent of reestablishing the anatomy and the correct function. The gingival area was submitted to 2 different wavelengths and then histologically analysed to search for alterations, mainly concerning mast cells behavior, a blood cell responsible, among other things, for blood vases enlargement. During the surgical procedure each gingival area was submitted to infrared low intensity laser ({lambda} = 785 nm) or to red laser ({lambda} = 688 nm), both with 50 mW of power and fluence of 8 J/cm{sup 2}. A third area was analysed, the control area, in which no laser treatment was employed. The samples were fixated in formol, cut and stained by hematoxyline eosine and toluidine blue. Based on the result we can conclude: the 2 wavelengths used in this study led to the reduction in the number of mast cells present in the tissue as well as to the increase on the degranulation of the remaining mast cells, considered statistically significant taken the degranulation index and; there was no significant difference caused by the action of the two laser wavelengths {lambda}=785 nm and {lambda}=688 nm -50 mW of power and fluence of 8 J/cm{sup 2}-, over the degranulation of the mast cells; the length and width of the randomly chosen blood vases were not statistically different among the analysed groups. (author)

  5. Adhesion of composite to enamel and dentin surfaces irradiated by IR laser pulses of 0.5-35 micros duration.

    Staninec, Michal; Gardner, Andrew K; Le, Charles Q; Sarma, Anupama V; Fried, Daniel


    The characteristics of laser-treated tooth surfaces depend on the laser wavelength, pulse duration, spatial and temporal laser beam quality, incident fluence, surface roughness, and the presence of water during irradiation. Ablated surfaces are most commonly restored with adhesive dental materials and the characteristics of the ablated surfaces influence adhesion of restorative materials. Previous studies suggest that high bond strengths can be achieved using shorter laser pulses that minimize peripheral thermal damage. In this study, Er:YSGG, Er:YAG, and CO(2) lasers were used at irradiation intensities sufficient to simulate efficient clinical caries removal to uniformly irradiate bovine enamel and human dentin surfaces using a motion control system with a microprocessor-controlled water spray. The degree of spatial overlap of adjacent pulses was varied so as to investigate the influence of irradiation uniformity and surface roughness on the bond strength. Composite resin was bonded to the irradiated surfaces and shear bond tests were used to obtain bond strengths in MPa. The highest results were obtained using the Er:YAG pulses with pulse durations less than 35 mus without the necessity for postirradiation acid etching. Some of these groups were not significantly different from nonirradiated, acid-etch-only positive control groups.

  6. In vitro study of the effects of cooling water temperature during the use of Er:YAG laser on dentin; Estudo in vitro dos efeitos da temperatura da agua de refrigeracao no uso de laser de Er:YAG em dentina

    Pinto, Ismael Lucas


    This study measured the pulp chamber and the target surface with 2 thermocouples, in order to determine whether cooling with water spray, with Er:YAG laser (Kavo Key 2), was overcooling the tooth, much beyond the necessary, during laser irradiation, within variation limits of 2.2 deg C of body temperature. The parameters used were: E{sub p}=250 mJ per pulse, with frequency ranging between 2 to 4 Hz, for a total DE of 80.20 J/cm{sup 2}, at an angle of incidence of approximately 90 deg, during an exposure period of 1 minute, totaling 120 to 240 pulses. In the first 40 seconds, the spray cooled the tooth rapidly, from 36.5 deg C to below 30 deg C. It was impossible to control the spray output temperature with a simple increase in reservoir temperature, for when water at temperatures ranging between 90 and 100 deg C is placed in the reservoir, the heat dissipates completely during the trajectory. The water jet does not present the same characteristics as a spray, which makes it impossible to conduct a perfect comparative analysis between them. The increase and maintenance of the spray output temperature, by reducing the temperature differential between that of the body and that of the spray of the Er:YAG laser, proved to be extremely promising. The pulp chamber temperature followed that of the spray or water jet, so that when a temperature that is lower than body temperature is used, the temperature of the pulp chamber is decreases, and when body temperature is surpassed, the temperature of the pulp chamber increases. (author)

  7. Comparative study of the action of two different types of bleaching agents activated by two different types of irradiation fonts: xenon plasma arc lamp and 960 nm diode laser; Avaliacao da cor e estudo comparativo da acao de dois tipos diferentes de agentes clareadores ativados pelo laser de diodo e lampada xenonio plasmatica, na superficie do esmalte

    Walverde, Debora Ayala


    This in vitro study compares two different types of tooth bleaching agents stimulated with two different irradiation fonts. These fonts accelerate the action of the bleaching agents upon the enamel surface by heating up the materials. We used the xenon plasma arc lamp and a 960 nm fiber-coupled diode laser to irradiate the two materials containing 35% of hydrogen peroxide (Opus White and Opalescence extra). The color of the teeth was measured with a spectrophotometer using the CIELAB color system that gives the numeric values of L{sup *}a{sup *}b{sup *}. (author)

  8. Effects of the copper vapour laser radiation in the root canal wall dentine: in vitro experiment using scanning electron microscopy and stereoscopy; Efeitos da radiacao laser de vapor de cobre na parede de dentina de canais radiculares: estudo in vitro por meio de microscopia eletronica de varredura e microscopio estereoscopico

    Silveira, Maria Claudia Garcia da


    Ten human uniradicular teeth had their crown removed along the cement-enamel junction and right away a proper chemical-surgical preparation of the radicular canals was done; the roots were longitudinally sectioned in order to allow the irradiation of the surfaces of the root canals wall dentine. The hemi-roots were separated in two groups: group I (control), with four hemi-roots, not irradiated; and group II, with 16 hemi-roots, subdivided in four sub-groups submitted to the following exposition time: 0,02 s; 0,05 s; 0,1 s and 0,5 s. A copper vapour laser was used with a 510,6 nm wavelength, total average power of 11 W in green and yellow emissions; average power of 6,5 W in green emission; pulse repetition rate of 16.000 Hz and pulse duration of 30 ns. The pulse energy (green line) is 0,4 mJ and the peak power 13,5 W. The laser cavity is unstable type (R{sub 1}=3.900 mm and R{sub 2}-250 mm). The focusing have focal length lens f{sub 1}=250 mm and f{sub 2}=150 mm. The beam quality is of the M{sup 2}=5. The results obtained by scanning electron microscopy analysis showed the appearance of a cavity in the region of the laser beam incidence in the edges of this cavity, dentin was melt and resolidified presenting also cracks due to heat diffusion. Based on these results, we concluded that the size of the cavity formed in the dentin is directly proportional to the rate of exposure and, the more laser emission in the same area, more damage in the root canals wall dentin occurs. More studies need to be done with different exposition's time in order to obtain a safety protocol that does not cause injury in dental and support tissue. (author)

  9. Comparative study of analgesic effect of the infrared low-intensity laser and 33% sodium fluoride paste in the treatment of dentinal hypersensitivity; Estudo comparativo do efeito analgesico do laser em baixa intensidade de emissao infravermelha e da pasta de fluoreto de sodio a 33% no tratamento da hipersensibilidade dentinaria

    Oliveira, Glen Anderson Maia de


    Different desensitizing agents have been used in the treatment of dentinal hypersensitivity, however, some presented treatments are still frustrating. The purpose of this study was to evaluate the analgesic effect of the low-intensity GaAlAs laser ({lambda}= 830 nm) in the treatment of dentinal hypersensitivity after mechanical and thermal stimuli, and compared it with the 33% sodium fluoride paste. Thirty two teeth with dentinal hypersensitivity were selected and randomly divided into two groups. For the laser group, each tooth was irradiated by a dose of 6 J/cm{sup 2} during two minutes and half on the buccal side. The paste group was treated with a NaF/kaolin/glycerin (33:33:33) paste by burnishing the sensitive surface during four minutes. The sensitivity degree was measured before the beginning of the experiment, 24 h, 48 h, 72 h, 120 h, 15 days and 30 days after the first application. The results indicate that the dentinal hypersensitivity significantly diminished for the paste group after dental explorer. Regarding to air-blast, no significant differences were observed between the groups. Both of them were effective in reducing pain of the dentine hypersensitive after 120 h. (author)

  10. Disturbios da olfacao: estudo retrospectivo

    Luciano Lobato Gregorio


    Full Text Available Introdução: O olfato, fenômeno subjetivo de grande importância, é pouco compreendido e estudado no ser humano. Médicos com maior conhecimento sobre os distúrbios desse sentido tendem a considerar a doença mais importante e manejar melhor o diagnóstico e o tratamento. Objetivo: Descrever a amostra dos pacientes com queixa principal de distúrbios do olfato e mostrar a experiência do serviço no manejo e tratamento. Delineamento: Estudo retrospectivo de coorte histórica com corte transversal. Materiais e métodos: Descrição da amostra e avaliação de resposta ao tratamento de pacientes com queixa principal de hiposmia ou anosmia atendidos no ambulatório de Rinologia no período de janeiro de 2005 a outubro de 2011. Resultados: Dos 38 pacientes com distúrbio da olfação, 68,4% dos pacientes apresentaram queixa de hiposmia e 31,5% de anosmia, com duração média de 30,8 meses. Os diagnósticos etiológicos principais foram idiopática (31,5%, rinopatia alérgica (28,9% e RSC com pólipos (10,5%. As respostas ao tratamento com corticosteroide tópico e ácido alfa-lipoico foram variáveis, assim como na literatura. Conclusão: Maior importância deve ser dada aos distúrbios do olfato na prática do otorrinolaringologista, uma vez que o diagnóstico diferencial é amplo e pode trazer grande morbidade ao paciente, com impacto na sua qualidade de vida.

  11. Comparative study of smear layer removal by different etching modalities and Er:YAG laser irradiation on the root surface: a scanning electron microscopy study; Estudo comparativo, atraves de microscopia eletronica de varredura, da acao de diferentes substancias quimicas e do laser de Er:YAG, na remocao de smear layer, em superficies radiculares submetidas a raspagem e aplainamento

    Theodoro, Leticia Helena


    The aim of this study was to compare the effects of citric acid, EDTA, citric acid with tetracycline, and Er:YAG laser to smear layer removal on the root surface after scaling with manual instruments by SEM. Thirty specimens (n=30) of root surface before scaling were divided into 6 groups (n=5). The Control Group (G1) was not treated; Group 2 (G2) was conditioned with citric acid gel 24%, pH1, during 2 minutes; Group 3 (G3) was conditioned with EDTA gel 24%, pH 7, during 2 minutes; Group 4 (G4) was conditioned with citric acid and tetracycline gel 50%, pH1 during 2 minutes; Group 5 (G5) was irradiated with Er:YAG laser (2.94 {mu}m), 47 mJ/10 Hz, focused, under water spray during 15 seconds and fluence of 0.58 J/cm{sup 2}; Group 6 (G6) was irradiated with Er:YAG laser (2.94{mu}m), 83 mJ/10 Hz, focused, under water spray during 15 seconds and fluence of 1.03 J/cm{sup 2}. The micrographic were analyzed by scores and following the statistical analysis with Kruskal Wallis (p<0.05) H=20,31. The G1 was significantly different of all groups (28.0); the G2 (13.4), G3 (11.7), and G4 (13.6) showed no difference in relation to G5 (20.3) and G6 (6.0), but the G6 was significantly different from G5. From the results, it can be conclude that: 1) there was intensity smear layer after scaling and root planing; 2) all treatments were effective to smear layer remove with significantly difference to G2, G3, G4, G5 and G6; G2, G3 and G4 were not statistically different from G5 and G6; 3) G6 was more effective in the smear layer remotion in relation to G5 and both presented irregular root surface. (author)

  12. Perioperative effects of oral midazolam premedication in children undergoing skin laser treatment: a double-blinded randomized placebo-controlled trial Efeitos peroperatórios da premedicação oral de midazolam em crianças submetidas a tratamento de pele por laser: estudo duplo-cego randomizado e controlado

    Mehrdad Shoroghi


    Full Text Available PURPOSE: To investigate and compare the efficacy of oral midazolam with two different dosages in orange juice on perioperative hemodynamics and behavioral changes in children who underwent skin laser treatment in an academic educational Hospital. METHODS: Ninety children, candidates for skin laser treatment were randomly assigned to 1 of 3 groups of 30 each: the placebo group received 0.1 ml/kg orange flavored juice, group 2 and 3 receiving 0.5 and 1 mg/kg of injectable midazolam mixed with an equal volume of orange juice, respectively. The main outcome measures included the mask acceptance, patients' behavioral scales and postoperative events. RESULTS: There were no significant differences in heart rate, respiratory rate, and systolic blood pressure among the three groups. However, arterial oxygen saturation was significantly reduced in those given 1 midazolam. The median scores of anxiety, separation from parent, preparing an intravenous line, acceptance of the oxygen mask, good sedation, crying reduction and consciousness level were better in midazolam group. Postoperative agitation and re-crying were also more frequent in placebo receivers. Those given 1 midazolam were significantly more optimal for sedation, crying, consciousness, preparing an intravenous line, and postoperative re-crying compared with 0.5 midazolam receivers. CONCLUSION: As a preanaesthetic medication, the 1 dose of orally given midazolam especially in a volume of orange juice and can optimize the children's behavior during skin laser treatment with no serious adverse effects, enhancing their parents' satisfactions about the sedative protocol.OBJETIVO:Investigar e comparar a eficácia do uso oral de midazolam com duas diferentes doses de suco de laranja na hemodinâmica peropeatória e mudanças de desempenho em crianças submetidas tratamento de pele por laser em Hospital educacional e acadêmico. MÉTODOS:Noventa crianças candidatas a

  13. Selective removal of carious dentin using a nanosecond pulsed laser with a wavelength of 6.02 μm

    Ishii, Katsunori; Saiki, Masayuki; Yasuo, Kenzo; Yamamoto, Kazuyo; Yoshikawa, Kazushi; Awazu, Kunio


    Conventional laser light sources for the treatment of a hard tissue in dental (Er:YAG laser, Er,Cr:YSGG laser and CO2 laser etc.) are good for removal of caries. However these lasers cannot achieve to give a selective treatment effect for caries without a side effect for normal tissue. The objective of this study is to develop the less-invasive treatment technique of carious dentin by selective absorption effect using the laser with a wavelength of 6.02 μm which corresponds to an absorption peak of organic matters called amide 1 band. Mid-infrared nanosecond pulsed laser by difference-frequency generation was used for the experiment of selective treatment. A tunable wavelength range, pulse width and repetition rate is from 5.5 to 10 μm, 5 ns and Hz, respectively. The laser with a wavelength of 6.02 μm and predetermined energy parameters was irradiated to the plate of carious dentin model which is made by soaking in lactic acid solution. After laser irradiation, the surface and cross-sectional surface of samples were observed by a scanning electron microscope (SEM). Average power density about 15 W/cm2 realized to excavate a demineralized region (carious dentin model) selectively in a SEM observation. In the same energy condition, serious side effect was not observed on the surface of normal dentin. A wavelength of 6.02 μm realizes a selective excavation of carious dentin. Using 6.02 μm is a novel and promising technique toward to next-generation dental treatment procedure for realizing MI.

  14. Spectroscopic characterization of iron-doped II-VI compounds for laser applications

    Martinez, Alan

    currently covered by available sources while maintaining absorption which overlaps with available pump sources. Because optimization of these materials requires extensive experimentation, a technique to fabricate and characterize novel crystals in powder form was developed, eliminating the need for the crystal growth. Powders were characterized using Raman, photoluminescence studies, and kinetics of luminescence. The first demonstration of random lasing of Fe:ZnCdTe powder at 6 microm was reported. These results show promise for the development of these TM-doped ternary II-VI compounds as laser gain media operating at 6 microm and longer. The second major objective was to study the performance of TM:II-VI elements as saturable absorber Q-switches and mode-lockers in flash lamp pumped Er:YAG and Er:Cr:YSGG cavities. Different cavity schemes were arranged to eliminate depolarization losses and improve Q-switching performance in Er:YAG and the first use of Cr:ZnSe to passively Q -switch an Er:Cr:YSGG cavity was demonstrated. While post-growth thermal diffusion is an effective way to prepare large-scale highly doped TM:II-VI laser elements, the diffusion rate of some ions into II-VI semiconductors is too low to make this method practical for large crystals. The third objective was to improve the rate of thermal diffusion of iron into II-VI semiconductor crystals by means of gamma-irradiation during the diffusion process. When exposed to a dose rate of 44 R/s during the diffusion process, the diffusion coefficient for Fe into ZnSe showed improvement of 60% and the diffusion coefficient of Fe into ZnS showed improvement of 30%.

  15. Comparative study of etched enamel and dentin for the adhesion of composite resins with the Er:YAG 2,94 {mu}m laser and CO{sub 2} 9,6 {mu}m laser: morphological (SEM) and tensile bond strength analysis; Estudo comparativo do condicionamento do esmalte e dentina para a adesao de resinas compostas com os lasers Er:YAG 2,94 {mu}m e com o laser CO{sub 2} de 9,6 {mu}m: analise morfologica e de resistencia a tracao

    Marraccini, Tarso Mugnai


    The aim of this study was to evaluate and compare the tensile bond strength of a composite resin adhered to the enamel and dentin which have received superficial irradiation with an Er:YAG laser (2.94 {mu}m) or with CO{sub 2} laser ( 9.6 {mu}m) and later on etched with the phosphoric acid at 35%. After the use of the adhesive system, resin cones were made on the etched surfaces by both lasers and tensile bond strength tests were performed. All samples were observed at the SEM - there was an increase of the degree of fusion and resolidification in the irradiated enamel and dentin samples with the CO{sub 2} laser (9.6 {mu}m), creating a vitrified layer with tiny craters. With the Er:YAG laser (2.94 {mu}m) there were typical morphological explosive microablation with the exposition of the tubules in the dentin.The surface acquired by the association of the CO{sub 2} laser ( 9.6 {mu}m) plus acid etching no longer presented the aspect of fusion being this layer completely removed. There were statistical significant differences among ali three methods of etching in the treatment of the enamel and dentin surface. The tensile bond strength test showed that etching of these enamel and dentin surfaces with acid exclusively (control group) presented great values, surpassing the values of the etching acquired with the Er:YAG laser (2.94 {mu}) plus acid or the CO{sub 2} laser (9.6 {mu}m) plus acid. With the parameters used in this experiment the Er:YAG laser (2.94 {mu}m) showed to be more effective than the CO{sub 2} laser (9.6 {mu}m) for the hard dental surfaces etching procedure. (author)

  16. O desamparo aprendido revisitado: estudos com animais

    Maria Helena Leite Hunziker

    Full Text Available O desamparo aprendido tem sido definido como a dificuldade de aprendizagem apresentada por indivíduos que tiveram experiência prévia com estímulos aversivos incontroláveis. O objetivo deste trabalho é fazer uma revisão crítica dos estudos sobre o desamparo aprendido, com animais. Nessa análise, são considerados aspectos conceituais e metodológicos dos estudos em questão e as interpretações teóricas sobre esse efeito comportamental. Aborda-se a evolução histórica desses estudos, bem como alguns aspectos controversos das publicações que se acumularam ao longo de quatro décadas de pesquisa. A associação do desamparo aprendido com a depressão clínica é analisada criticamente, destacando-se a necessidade de maior rigor metodológico e conceitual nos estudos da área.

  17. Estudos transcriptômicos no contexto da conectividade perturbada em esquizofrenia

    Andrea Schmitt


    Full Text Available Esquizofrenia é uma severa doença neurobiológica com fatores genéticos e ambientais desempenhando um papel na fisiopatologia. Diversas regiões cerebrais têm sido implicadas no processo da doença e estão conectadas em complexos circuitos neuronais. Nos níveis molecular e celular, a conectividade afetada entre essas regiões, envolvendo mielinização disfuncional dos axônios neuronais, bem como as alterações no nível sináptico e metabolismo energético levando a distúrbios na plasticidade sináptica, são os maiores achados em estudos post-mortem. Estudos de microarranjos investigando a expressão gênica contribuíram para os achados de alterações em vias complexas em regiões cerebrais relevantes na esquizofrenia. Além disso, estudos utilizando microdissecção e captura a laser permitiram a investigação da expressão gênica em grupos específicos de neurônios. Entretanto, deve ser mantido em mente que em estudos post-mortem, confusos efeitos de medicação, qualidade de RNAm, bem como capacidade de mecanismos regenerativos neuroplásticos do cérebro em indivíduos com história de vida de esquizofrenia, podem influenciar o complexo padrão de alterações no nível molecular. Apesar dessas limitações, estudos transcriptômicos livres de hipóteses em tecido cerebral de pacientes esquizofrênicos oferecem uma possibilidade única para aprender mais sobre os mecanismos subjacentes, levando a novas ópticas da fisiopatologia da doença.

  18. Lasers technology



    The Lasers Technology Program of IPEN is committed to the development of new lasers based on the research of optical materials and new technologies, as well to laser applications in several areas: Nuclear, Medicine, Dentistry, Industry, Environment and Advanced Research. The Program is basically divided into two main areas: Material and Laser Development and Laser Applications.


    Maria Verônica de Souza; Micheline Ozana da Silva


    RESUMO Introdução: Ao longo dos anos a fisioterapia tem contribuído para o tratamento das lesões musculotendíneas e osteoarticulares pela utilização de diversos recursos eletrotermofototerapêuticos como, por exemplo, o laser de baixa potência. Objetivo: A finalidade desse estudo foi identificar mediante revisão sistemática, o efeito da laserterapia de baixa potência em afecções do sistema locomotor de ratos, com destaque para a dose de energia e o comprimento de onda utilizado, assim como...

  20. Gigawatt mid-IR (4-5 μm) femtosecond hybrid Fe2+:ZnSe laser system

    Potemkin, F. V.; Migal, E. A.; Pushkin, A. V.; Bravy, B. G.; Sirotkin, A. A.; Kozlovsky, V. I.; Korostelin, Yu. V.; Podmar'kov, Yu. P.; Firsov, V. V.; Frolov, M. P.; Gordienko, V. M.


    We demonstrate a first-of-its-kind efficient chirped pulse amplification of broadband mid-IR (4-5 μm) femtosecond seed pulse (230 ps, 4μJ) generated in AgGaS2 based OPA driven by Cr:forsterite laser in multi-pass Fe2+:ZnSe amplifier optically pumped by solid-state Q-switched Cr:Yb:Ho:YSGG laser (2.85 μm, 30mJ, 5Hz, 0.6 J/cm2). The system delivers 1.2 mJ at pulse duration of 230 ps. Straightforward compression to 150 fs pulse is achievable with 70% efficiency using diffraction grating pair with peak power of about 6 GW. Further non-linear compression in a bulk CaF2 due to the SPM and anomalous GVD should provide the enhancement of peak power up to 20 GW. Possible routes to reach sub-TW and even TW power level in mid-IR are discussed.

  1. Hard tissue ablation with a spray-assisted mid-IR laser

    Kang, H W [American Medical Systems, Minnetonka, MN (United States); Rizoiu, I [BioLase Technology, Irvine, CA (United States); Welch, A J [Department of Biomedical Engineering, University of Texas at Austin, Austin, TX (United States)


    The objective of this study was to understand the dominant mechanism(s) for dental enamel ablation with the application of water spray. A free-running Er,Cr:YSGG (yttrium, scandium, gallium, garnet) laser was used to ablate human enamel tissue at various radiant exposures. During dental ablation, distilled water was sprayed on the sample surface, and these results were compared to ablation without a spray (dry ablation). In order to identify dominant ablation mechanisms, transient acoustic waves were compared to ablation thresholds and the volume of material removed. The ablation profile and depth were measured using optical coherence tomography (OCT). Irregular surface modification, charring and peripheral cracks were associated with dry ablation, whereas craters for spray samples were relatively clean without thermal damage. In spite of a 60% higher ablation threshold for spray associated irradiations owing to water absorption, acoustic peak pressures were six times higher and ablation volume was up to a factor of 2 larger compared to dry ablation. The enhanced pressure and ablation performance of the spray-assisted process was the result of rapid water vaporization, material ejection with recoil stress, interstitial water explosion and possibly liquid-jet formation. With water cooling and abrasive/disruptive mechanical effects, the spray ablation can be a safe and efficient modality for dental treatment.


    Alba S. B. Lopes


    Full Text Available Arquiteturas reconfiguráveis são dispositivos de hardware capazes de modificar sua estrutura de hardware de acordo com a aplicação a ser executada. Tais dispositivos surgiram como uma alternativa às soluções de hardware tradicionais na tentativa de equilibrar flexibilidade e desempenho. Uma das principais formas de utilização de arquiteturas reconfiguráveis corresponde a um bloco reconfigurável anexado a um processador hospedeiro. Esse processador é responsável por executar diversas tarefas críticas, incluindo o particionamento hardware/software e indicar o momento do bloco reconfigurável executar. Apesar de existirem diversas propostas de arquiteturas reconfiguráveis na literatura, pouco se estudou sobre o impacto do processador hospedeiro na arquitetura. Nesse contexto, esse artigo apresenta um estudo sobre o impacto do processador hospedeiro no desempenho da arquitetura reconfigurável híbrida. Como estudo de caso foi realizada uma avaliação sobre o uso dos processadores SPARC V8 da Sun Microsystems e Nios II da Altera como processadores hospedeiros da arquitetura reconfigurável híbrida RoSA. O objetivo deste estudo é realizar a comparação entre o desempenho desses processadores e identificar qual deles é o mais adequado para anexar a arquitetura em questão. Os resultados mostraram que foi possível alcançar até 47% de ganho de desempenho com o uso do processador Nios II em comparação ao SPARC V8, indicando o primeiro como mais adequado para a arquitetura RoSA. PALAVRAS-CHAVE: arquiteturas reconfiguráveis, processador hospedeiro, desempenho.

  3. \\"Estudo da evolução da reação de presa do cimento de fosfato de zinco através de luz laser, aplicando a técnica óptica de speckle dinâmico\\"


    A cimentação de próteses e/ou de outros elementos protéticos constituem-se em uma preocupação permanente, já que uma das grandes aplicações do cimento de fosfato de zinco é como agente cimentante. No entanto, a reação de presa do cimento de fosfato de zinco, assim como o tempo de sua presa final, não estão ainda completamente esclarecidos. O presente estudo visa analisar, microestruturalmente, a evolução da reação de presa do cimento de fosfato de zinco. Mais especificamente, buscou-se mensur...

  4. Comparative analysis of bacterial decrease by Er:YAG laser radiation and by a tip mounted on a high-rotation device after remove of carious tissue in dentine: study 'in anima mobile'; Analise comparativa da reducao bacteriana com irradiacao do laser Er:YAG ou ponta montada em alta rotacao apos remocao de tecido cariado em dentina: estudo in anima nobile

    Blay, Claudia Campos


    The purpose of this study was to analyze bacterial decrease after removal of carious tissue in dentine by Er:YAG laser, comparing the results with those achieved by using a tip mounted on a high-rotation device. In view of the difficulty of totally eliminating microorganisms from dentine, even after removing all the carious tissue, and since the presence of a smear layer is a proven fact, it would be extremely convenient to eliminate or to achieve better disinfecting of this notoriously contaminated dentine layer, so as to prevent failure of the restoration process in most cases. For this study, we selected 30 pre-molars and molars with caries rated as medium sized and which required restoration treatment. The teeth were divided in two groups, where 15 teeth received conventional treatment (control group - I) and 15 teeth were treated with Er:YAG laser (Kavo Key Laser) (laser group - II). Microbiologic analysis was used in order to determine presence or absence of bacteria. In group I as well as in group II a previous curettage of part of the dentine caries was performed, and the sample was seeded in an Agar culture medium and incubated at 37 deg C for 72 hours, for a quantitative analysis of bacteria colony forming units (c.f.u.) and qualitative bacterial analysis. After this procedure, carious lesions were removed in group I, using a spherical diamond drill mounted on a high rotation tip, followed by cleaning of the cavity with chlorhexidine digluconate at 2%. In group II, an Er:YAG laser emitting a wave length of 2,94 {mu}m, delivering a 250 mJ energy per pulse at a repetition rate of 2 Hz was used for carious tissue removal. Furthermore in group II (laser), the cavity was conditioned by performing a sweeping at all walls of the preparation with the 50/10 fiber (Kavo), in contact mode, using an energy of 60 mJ per pulse at a frequency of 10 Hz. After removing all caries and performing a cleaning operation in both groups, dentine shavings were collected and

  5. Blue Laser.


    HOLLOW CATHODE LASER FABRICATION 13 4. EXPERIENCE WITH THE BLUE LASER 18 4.1 Operational and Processing Experience 18 4.2 Performance Testing 20 5...34 -. - . •. SECTION 3 BLUE HOLLOW CATHODE LASER FABRICATION This section presents an overview of the steps taken in creating a HCL. There the laser assembly. These steps can actually be considered as the final steps in laser fabrication because some of them involve adding various

  6. Evaluation of Surface Roughness and Bacterial Adhesion on Tooth Enamel Irradiated With High Intensity Lasers.

    Nogueira, Ruchele D; Silva, Camilla B; Lepri, Cesar P; Palma-Dibb, Regina Guenka; Geraldo-Martins, Vinicius R


    The aim was to evaluate the surface roughness and bacterial adhesion on enamel irradiated with high intensity lasers, associated or not to a fluoride varnish. Eighty fragments of bovine enamel were equally divided in 8 groups (n=10). Group 1 was not treated and Group 2 received only a 5% fluoride varnish application. The other groups were irradiated with an Er:Cr:YSGG (8.92 J/cm2), an Nd:YAG (84.9 J/cm2) and a diode laser (199.04 J/cm2), associated or not to a 5% fluoride varnish. The surface roughness was measured before and after treatments. Afterward, all samples were incubated in a suspension of S. mutans at 37 °C for 24 h. The colony-forming units (CFU) were counted by a stereoscope and the results were expressed in CFU/mm2. One-way ANOVA and the Tukey´s test compared the roughness data and the Student´s test compared the results obtained in the bacterial adhesion test (a=5%). The results showed that the irradiated samples without varnish presented the same roughness and the same bacterial adhesion that the non-irradiated samples. However, samples irradiated in the presence of fluoride varnish showed higher surface roughness and higher bacterial adhesion than the non-irradiated samples and those irradiated without varnish. Presence of pigments in the varnish increased the lasers' action on the enamel surface, which produced ablation in this hard tissue and significantly increased its surface roughness. For this reason, the enamel's susceptibility to bacterial adhesion was higher when the irradiation of the samples was made in presence of fluoride varnish.

  7. Treatment of microleakage of root caries after Er, Cr: YSGG laser preparation%根面龋应用激光去腐充填修复后的微渗漏研究

    焦倩倩; 赵涓彤; 吴佩玲


    目的 探讨根面龋应用Er,Cr:YSGG激光去腐充填后充填体与洞壁间的微渗漏情况.方法 根面有龋损的离体牙20颗,随机分为观察组与对照组各10颗牙,观察组应用Er,Cr:YSGG激光去腐备洞,对照组应用高速手机去腐备洞,之后均充填富士Ⅱ型玻璃离子.采用热力循环法和染料渗入法处理充填完成的离体牙,体视显微镜和扫描电镜下观察充填体与洞壁间的微渗漏情况.结果 2组染料渗透情况比较差异无统计学意义(P>0.05);观察组和对照组充填体边缘微缝隙在(牙合)壁的间隙宽度分别为(0.655±0.048)、(0.633±0.050)μm,在龈壁的间隙宽度分别为(0.545±0.089)、(0.543±0.075)μm,差异无统计学意义(P>0.05).结论 应用Er,Cr:YSGG激光对根面龋去腐充填,不会降低充填体与洞壁间微渗漏的发生率.


    Maria Verônica de Souza


    Full Text Available RESUMO Introdução: Ao longo dos anos a fisioterapia tem contribuído para o tratamento das lesões musculotendíneas e osteoarticulares pela utilização de diversos recursos eletrotermofototerapêuticos como, por exemplo, o laser de baixa potência. Objetivo: A finalidade desse estudo foi identificar mediante revisão sistemática, o efeito da laserterapia de baixa potência em afecções do sistema locomotor de ratos, com destaque para a dose de energia e o comprimento de onda utilizado, assim como para a resposta ao tratamento. Métodos: Foram consultadas as bases de dados Medline, Lilacs, PEDro e SciELO, entre janeiro de 2005 a maio de 2013, utilizando os termos "tendinopathy", "laser therapy", "rats", "tendon", "muscle", "bone", "low-level laser therapy", assim como "tendinopatia", "laserterapia", "ratos", "tendão", "músculo", "osso" e "laser de baixa potência". Apenas foram incluídos estudos experimentais publicados nos idiomas português e inglês, que induziram lesão em tendões, músculos, ossos e/ou articulação, tratada com laserterapia, associada ou não a outros tratamentos. Resultados: Foi encontrado um total de 30 estudos experimentais nas bases de dados consultadas, dos quais 15 (50% foram realizados em tendão, 10 (33,33% em músculo e cinco (16,66% em osso e/ou articulação. As doses de energia mais comumente utilizadas foram de 3 J (26,66% e 1 J (16,66%. Já os comprimentos de onda foram de 904 nm (21,21% e 830 nm (21,21%. Conclusão: A informação mais expressiva obtida com a terapia foi a diminuição da resposta inflamatória (36,66% em lesões ortopédicas agudas.

  9. Comparative study of the effects of photodynamic therapy and conventional therapy on ligature induced peri-implantitis in dogs; Estudo comparativo dos efeitos do laser de baixa potencia associado a fotossensibilizador e terapia convencional em periimplantes induzidas em mandibulas de caes

    Hayek, Ricardo Rada Ahmad


    Progressive peri-implanter bone losses, which are accompanied by inflammatory process in the soft tissues is referred to as peri-implantitis. The aim of this study was to compare the effects of lethal photosensitisation with the conventional technique on bacterial reduction in ligature induced peri-implantitis in dogs. Seventeen third pre-molars of Labrador dogs were extracted and, immediately after, the implants were submerged. After osteointegration, peri-implantitis was induced. After 4 months, ligature were removed and the same period was waited for natural induction of bacterial plaque. The dogs were randomly divided into two groups. In the conventional group, they were treated with the conventional techniques of mucoperiosteal flaps for scaling the implant surface and irrigate it. In the laser group, only mucoperiosteal scaling was carried out before photodynamic therapy. On the peri-implanter pocket an azulene paste was injected and a GaAlAs low-power laser ({lambda}= 660 nm, P= 30 mW, E= 5,4 J and {delta}t= 3 min.). Microbiological samples were obtained before and immediately after treatment. One implant was removed to be analyzed by scan electron microscopy to verify contamination on the implant surface. The results of this study showed that Prevotella sp., Fusobacterium e S. Beta-haemolyticus were significantly reduced for the conventional and laser groups. (author)

  10. In vitro evaluation of the effects of the interaction between irrigating solutions, intracanal medication and Er:YAG laser in dentin permeability of the endodontic system Estudo in vitro dos efeitos da interação de substâncias irrigantes, medicação intracanal e laser Er:YAG na permeabilidade dentinária do sistema endodôntico

    Denise Pontes Raldi


    Full Text Available The purpose of this study was to evaluate in vitro the effects of different associations between irrigating solutions (EDTA-T and citric acid, intracanal medicament (NDP, and Er:YAG laser irradiation on dentin permeability. Fifty-one extracted single-rooted teeth were instrumented and divided into seven groups. Groups GI and GII had final irrigation with a demineralizing solution only (EDTA-T and citric acid, respectively. Groups GIII and GIV had final irrigation with EDTA-T and citric acid, respectively, plus an association of irrigating solution and Er:YAG laser. Groups GV and GVI had final irrigation with EDTA-T and citric acid, respectively, plus an association of intracanal medication and Er:YAG laser. Group GVII (control group had final irrigation with distilled water. All root canals were filled with NDP associated with rhodamine B dye. After the experimental period, the samples were transversely cut into six 2.0 mm thick slices for subsequent reading using the ImageLab software. Analysis of the results allowed us to conclude that there were statistically significant differences (p Este experimento teve como objetivo avaliar in vitro os efeitos da interação entre soluções irrigantes desmineralizadoras (EDTA-T e ácido cítrico, medicação intracanal (NDP e laser Er:YAG na permeabilidade dentinária. Foram utilizados 51 dentes unirradiculares extraídos que, após o preparo químico-cirúrgico, foram divididos em sete grupos experimentais: grupos I e II - irrigação final com solução de EDTA-T e ácido cítrico, respectivamente; grupos III e IV - irrigação final com EDTA-T e ácido cítrico, respectivamente, mais a associação entre solução irrigante e laser Er:YAG; grupos V e VI - irrigação final com EDTA-T e ácido cítrico, respectivamente, mais a associação entre medicação intracanal e laser Er:YAG, e grupo VII (controle - irrigação final com água destilada. Os canais radiculares foram preenchidos com o corante

  11. The Effect of Laser Irradiation on Shear Bond Strength of GI to Dentin After CPP-ACP Treatment



    Full Text Available Background Dentin sensitivity is one of the most important problems in dentistry. Enamel loss due to root exposure is serious issue and common exposure is one of the reasons for dentin hypersensitivity. There are different methods for solving this problem. One of the most conservative and least expensive methods is use of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP paste. Objectives The aim of this study was to evaluate shear bond strength of GIC to dentin, with or without laser, CPP-ACP paste and polyacrylic acid treatments. Materials and Methods Fifty sound human third molars were bisected in a mesiodistal direction using a diamond disk. Using 400, 600 and 800 grit silicon carbide paper, dentin surfaces were exposed. The teeth were divided into five groups. In groups A, B, D and H, CPP-ACP (GC tooth mousse Itabashi-Ku, Tokyo, Japan was applied for one hour the first day and repeated at the same time of day for a total of five days. In groups B, C, D and E, the specimens were subjected to laser for 10 seconds using Er, Cr: YSGG laser. In groups B, C, H and G, specimens were treated with 10% polyacrylic acid for 20 seconds. A plastic tube containing GI was positioned over the tooth. Samples were loaded in shear bond using a Universal Testing Machine (Zwick/Roell, Germany, at a 0.5 mm/minute crosshead speed. Results Despite the failing of groups A and D, group analysis showed that there were no significant differences between the groups. The predominant type of fracture in all groups was adhesive. Conclusions Application of CPP-ACP, without preconditioning with polyacrylic acid, can decrease shear bond strength. Laser irradiation has no effect on shear bond strength of GIC to dentin in this condition.

  12. Estudo do teor de alicina em alho

    Mendes, Patrícia Alexandra Pinto


    A alicina (dialil-tiosulfinato) é o componente biológico mais activo no alho com inúmeras aplicações a nível da saúde, já conhecida desde décadas. Existem actualmente diversos métodos publicados para a determinação do teor de alicina no alho por HPLC e espectrofotometria. No entanto, os resultados mostram discordância no teor de alicina medido pelos vários métodos. Este estudo tem por objectivo a determinação do teor de alicina por métodos de HPLC e espectrofotometria; e com...

  13. O estudo do comportamento verbal no Brasil

    Adriana Pineiro Fidalgo

    Full Text Available O presente trabalho realizou uma revisão histórica de dissertações de mestrado e teses de doutorado brasileiras sobre comportamento verbal, com base na proposta Skinneriana (1957/1992, produzidas entre 1968 e 2012. Foram investigados: a tipo de trabalho (dissertação ou tese, b universidades em que os trabalhos foram defendidos, c orientadores, d linha de pesquisa (básica, aplicada ou histórico-conceitual, e metodologia (descritiva ou experimental, e f temas de investigação. No total, 177 dissertações e 53 teses sobre comportamento verbal foram identificadas. Os resultados indicam que o estudo do comportamento verbal, no Brasil, estabeleceu-se como programa de pesquisa e cresceu ao longo dos anos.

  14. Estudo forense do sémen

    Vaz, Josiana A.; Chelas, S.; S Santos; Queirós, B.; Gonçalves, A.; Pereira, M.; Alves, Maria José


    O estudo dos fluidos seminais na cena do crime está directamente ligado a crimes de índole sexual, sendo este de importância vital aquando da reconstrução do acto do crime e na identificação do agressor. O sémen é segregado pelos órgãos reprodutores masculinos, sendo o suporte líquido dos espermatozóides. Segundo Pinheiro (2008), este vestígio pode ser encontrado em manchas no vestuário, lençóis, almofadas, móveis, chão, veículos, tapetes, entre outros. O sémen, antes de secar, possui um o...

  15. Lasers technology



    The Laser Technology Program of IPEN is developed by the Center for Lasers and Applications (CLA) and is committed to the development of new lasers based on the research of new optical materials and new resonator technologies. Laser applications and research occur within several areas such as Nuclear, Medicine, Dentistry, Industry, Environment and Advanced Research. Additional goals of the Program are human resource development and innovation, in association with Brazilian Universities and commercial partners.

  16. Lasers (Rev.)

    Hellman, Hal


    A laser is an instrument that produces an enormously intense pencil-thin beam of light. In this booklet we shall learn what there is about the laser that gives it so much promise. We shall investigate what it is, how it works, and the different kinds of lasers there are.

  17. Laser device

    Scott, Jill R.; Tremblay, Paul L.


    A laser device includes a target position, an optical component separated a distance J from the target position, and a laser energy source separated a distance H from the optical component, distance H being greater than distance J. A laser source manipulation mechanism exhibits a mechanical resolution of positioning the laser source. The mechanical resolution is less than a spatial resolution of laser energy at the target position as directed through the optical component. A vertical and a lateral index that intersect at an origin can be defined for the optical component. The manipulation mechanism can auto align laser aim through the origin during laser source motion. The laser source manipulation mechanism can include a mechanical index. The mechanical index can include a pivot point for laser source lateral motion and a reference point for laser source vertical motion. The target position can be located within an adverse environment including at least one of a high magnetic field, a vacuum system, a high pressure system, and a hazardous zone. The laser source and an electro-mechanical part of the manipulation mechanism can be located outside the adverse environment. The manipulation mechanism can include a Peaucellier linkage.

  18. Laser thruster

    Jalufka, N. W.


    Laser propulsion can reduce fuel by 57 t to 105 t over chemical propulsion for a 144 t Lunar base, with no significant increase in trip time. Laser propulsion reduces trip time by a factor of 40 to 120 over nuclear electric propulsion and time in radiation belts by a factor of 100 to 1700. Either solar or nuclear driven laser diode arrays could produce multimegawatt beams, typically 3,700 t for a 235 MW laser system. Laser diode arrays have high payoff due to short wavelength (850 nm) and high diode efficiency (70 percent). A dry laser OTV of 8790 kg and 60 percent efficiency can transport a 144 t lunar base. Laser propulsion could carry both personnel and cargo safely to the lunar base.

  19. Laser photocoagulation - eye

    Laser coagulation; Laser eye surgery; Photocoagulation; Laser photocoagulation - diabetic eye disease; Laser photocoagulation - diabetic retinopathy; Focal photocoagulation; Scatter (or pan retinal) photocoagulation; Proliferative ...


    Larissa Assunção


    Full Text Available Com o advento da nanotecnologia, houve o desenvolvimento de técnicas envolvendo processamento, fabricação e aplicação de estruturas, com forma e tamanho controlados, sendo que na indústria de alimentos, estas formulações, tanto na faixa micrométrica como nanométrica, vêm sendo utilizadas com o objetivo de favorecer o produto final. Tendo em vista a importância tecnológica dessa técnica e do grande interesse nacional e internacional, principalmente no ramo da indústria alimentícia, sobre os benefícios do encapsulamento, o presente estudo prospectivo teve como objetivo avaliar o panorama mundial relativo ao tema em questão, correlacionando-o com os documentos de patentes depositados. Para tanto, realizou-se uma pesquisa das patentes na base de dados europeia Espacenet®, utilizando os descritores do tema em estudo associados aos códigos de classificação. As informações encontradas foram compiladas em gráficos e discutidas. Pôde-se observar que o maior número de patentes referiu-se ao código A23L1/00 - alimentos ou produtos alimentícios: a sua preparação ou tratamento e houve um crescimento exponencial em relação ao depósito de patentes nos últimos 10 anos, sendo os Estados Unidos o país líder em número de patentes depositadas (60%. A Firmenich e CIE lidera o ranking com mais patentes depositadas. Em relação à área de atuação, predomina a indústria alimentícia (69%. No que diz respeito ao Brasil, o país aparece com apenas 1 patente detentora desta tecnologia, sendo um número bastante reduzido o que mostra a falta de incentivo neste setor. Diante dos resultados obtidos, concluiu-se que, apesar de ser uma tecnologia recente, observa-se uma tendência ao crescimento de depósito de patentes.


    Mota, Julio


    Este trabalho visa examinar como a necessidade de Laban conhecer as leis que regem o movimento humano o levou ao desenvolvimento de um método científico de estudo a que ele chamou de Coreologia. E de como a necessidade de aplicar o método coreológico, de maneira específica à Dança, conduziu ao surgimento de uma área específica de estudos, denominada Estudos Coreológicos. Este processo é aqui analisado através de um breve resumo biográfico de Laban. Essa biografia mostra como as in...

  2. Estudo retrospectivo de latrodectismo na Bahia, Brasil

    Rejâne Maria Lira-da-Silva


    Full Text Available O trabalho apresenta um estudo retrospectivo de setenta e sete casos de latrodectismo no Estado da Bahia, Brasil, de agosto de 1980 a julho de 1990. Os dados foram levantados nos livros de registro e arquivo de fichas do CIAVE. O agente etiológico em 28% dos acidentes aracnídeos foi a espécie L. curacaviensis e a maior incidência foi registrada no meio urbano (57%, em indivíduos do sexo masculino (70% e faixa etária de 10 a 29 anos (58%. Os principais sinais locais foram dor (56%, pápula eritematosa (21% e edema discreto (17%, e os sistêmicos foram dor em membros inferiores (29%, tremores e contraturas (29%, sudorese (28% parestesia em membros (21% e dor abdominal (17%. O tratamento foi sintomático em 67% dos casos e específico em 21%. O tempo de permanência hospitalar após o uso do soro antilatrodectus foi menor que 24 horas em 64% dos casos.

  3. Habilidades Sociais em Alcoolistas: Um Estudo Comparativo

    Flaviane Bevilaqua Felicissimo

    Full Text Available RESUMO O presente estudo objetivou comparar o repertório de habilidades sociais (HS de dependentes e não dependentes de álcool a fim de verificar se um menor repertório de HS constitui uma característica dessa população. Foram entrevistados 123 alcoolistas e 114 usuários de serviços de saúde com baixo ou nenhum consumo de álcool, utilizando questionário sociodemográfico, Mini International Neuropsychiatric Interview e o Inventário de Habilidades Sociais. Os dados foram analisados quantitativamente e indicaram uma diferença significativa no repertório de HS, especificamente no fator de autocontrole da agressividade, indicando um pior desempenho dessa habilidade em alcoolistas. Os resultados sugerem que a avaliação dessa característica deva ser considerada no tratamento do alcoolismo e associada ao plano terapêutico.

  4. Paralisia periodica familiar: estudo de oito casos

    José Lamartine De Assis


    Full Text Available Foram estudados oito pacientes com Paralisia Periódica Familiar sob os aspectos clínico, hidro-eletrolítico, eletrofisiológico, histológico e terapêutico. Houve predomínio significante em pacientes do sexo masculino. A idade média do início da moléstia foi de 15 anos. As manifestações clínicas foram concor-dantes com as referidas na literatura. Todos os pacientes tinham a forma hipocalêmica exceto um que evoluiu com hipercalemia. Alguns pacientes (21,4% tinham natremias no limite superior da normalidade enquanto em um número igual de pacientes as natremias estavam elevadas, o que sugeria liberação de aldosterona. Os achados eletrofisiológicos foram concordantes com os da literatura. O estudo histológico de músculos realizado em cinco pacientes foi normal em 30% deles e, naqueles com crises repetidas e freqüentes, foram encontradas atrofias de fibras musculares. Foram feitos tratamentos preventivos, e nos pacientes com hipocalemia foram administradas doses suplementares de potássio em solução aquosa de 10-25% diariamente.

  5. A laser

    Togo, N.; Syundzo, Yo.


    It is reported that an improved gas laser design using pumping of the active medium has been developed. A diagram of the laser system is given in graph form and its principle of operation is briefly described. A special sealing element is used in such lasers to seal the reservoir containing the oil in the pump which pumps the gas active medium. When the sealing element fails, there is the danger of oil penetration into the active laser medium. It is proposed that an additional pump which continually evacuates the oil reservoir during laser system operation be used. Thus, a low pressure is maintained in the reservoir. If the sealing element fails, the secondary pump generates a gas flow from the pumping system to the reservoir and eliminates gas penetration into the laser medium.

  6. Biocavity Lasers

    Gourley, P.L.; Gourley, M.F.


    Laser technology has advanced dramatically and is an integral part of today's healthcare delivery system. Lasers are used in the laboratory analysis of human blood samples and serve as surgical tools that kill, burn or cut tissue. Recent semiconductor microtechnology has reduced the size o f a laser to the size of a biological cell or even a virus particle. By integrating these ultra small lasers with biological systems, it is possible to create micro-electrical mechanical systems that may revolutionize health care delivery.

  7. Estudo retrospectivo de latrodectismo na Bahia, Brasil

    Rejâne Maria Lira-da-Silva


    Full Text Available O trabalho apresenta um estudo retrospectivo de setenta e sete casos de latrodectismo no Estado da Bahia, Brasil, de agosto de 1980 a julho de 1990. Os dados foram levantados nos livros de registro e arquivo de fichas do CIAVE. O agente etiológico em 28% dos acidentes aracnídeos foi a espécie L. curacaviensis e a maior incidência foi registrada no meio urbano (57%, em indivíduos do sexo masculino (70% e faixa etária de 10 a 29 anos (58%. Os principais sinais locais foram dor (56%, pápula eritematosa (21% e edema discreto (17%, e os sistêmicos foram dor em membros inferiores (29%, tremores e contraturas (29%, sudorese (28% parestesia em membros (21% e dor abdominal (17%. O tratamento foi sintomático em 67% dos casos e específico em 21%. O tempo de permanência hospitalar após o uso do soro antilatrodectus foi menor que 24 horas em 64% dos casos.This work is a retrospective study of latrodectism in the State of Bahia, Brazil, from August 1980 to July 1990. The data concerning the accidents were obtained from file cards at the Antivenom Information Center of Bahia (AVICB. Latrodectus curacavienis was the ethiologic agent identified in 28% of the arachnid accidents. The major incidence was registered in urban area (57% affecting men (70% more than women, with 10 to 29year-old age group (58%. Local pain (56%, erythematous papula (29% and light oedema (17% were the principal local symptoms. Pain in the limbs (29%, tremor and rigidities (29%, sweating (28%, limbs and arms paresthesia (21% and abdominal pain (17% were systemic ones. The treatment was mainly symptomatic (67% and antivenin serum was used in 21% of the cases. After serotherapy, 64% of the patients left the hospital within less than 24 hours.

  8. Valor do estudo citogenetico no transexualismo

    P. H. Saldanha


    Full Text Available O transexualismo é caracterizado como uma entidade psiquiátrica, distinta do homossexualismo e travestismo, revendo-se suas manifestações sindrômicas. Discutem-se as duas principais causas etiológicas plausíveis do transexualismo, a saber: a hipótese psicoanalítica fundamentada na regressão psicossexual com estampagem da figura materna e o modelo neuro-endócrino que pressupõe alterações nos centros de identidade sexual do hipotámo. Com base nesta última explicação propõe-se, a exemplo do que parece ocorrer na síndrome de Morris, cujas células (XY não respondem ao efeito masculinizante da testosterona plasmática, que os transexuais devem possuir mosaicismo detectável ou críptico, quanto aos cromossomos sexuais, nos centros hipotalâmicos de identidade sexual que não respondem à secreção androgênica produzida pela gônada primitiva. Esta possibilidade explicaria a excessiva prevalência da síndrome entre homens, bem como a sua manifestação com feições típicas no sexo masculino e ainda a ocorrência esporádica da síndrome. O estudo citogenético revelou que a frequência (32% de mosaicismo quanto aos cromossomos sexuais em 25 transexuais é estatisticamente superior aos valores observados em 14 homossexuais e 40 controles normais, nos quais a proporção de mosaicismo é praticamente nula. Considera-se a possibilidade do critério cariotípico constituir valioso subsídio na diagnose da síndrome.

  9. Histerectomias: estudo retrospectivo de 554 casos

    Eddie Fernando Cândido Murta

    Full Text Available OBJETIVO: A histerectomia é uma operação muito realizada, entretanto há poucos trabalhos na literatura nacional sobre suas indicações, técnica e complicações. O objetivo deste trabalho é avaliar estes procedimentos realizados na Disciplina de Ginecologia e Obstetrícia da Faculdade de Medicina do Triângulo Mineiro. MÉTODO: Estudo retrospectivo de 470 histerectomias abdominais e 84 vaginais foi conduzido analisando as indicações, tempo de cirurgia e internação, tipo de incisão e morbidez. RESULTADOS: As principais indicações foram o mioma uterino e o prolapso uterino para as histerectomias abdominais e vaginais, respectivamente. As complicações intra-operatórias aconteceram em 3,4% e as pós-operatórias em 2,4% do total de casos. Nenhuma diferença estatística foi encontrada no número de complicações em relação ao tipo de incisão (vertical ou transversal. O tempo de cirurgia e o de hospitalização foram estatisticamente maiores nas incisões verticais. A hemorragia foi a mais freqüente complicação intra-operatória e a infecção da incisão operatória foi a mais freqüente no pós-operatório. CONCLUSÕES: A histerectomia é um procedimento de baixo risco, no entanto, a realização de revisões sobre indicações e complicações, e a pesquisa de melhores técnicas cirúrgicas são necessárias para torná-la cada vez mais segura.

  10. Reticulossarcomas epidurais intraespinais: estudo de 34 casos

    Lígia M. B. Coutinho


    Full Text Available Foi realizado um estudo de 34 casos de reticulossarcomas localizados no tecido epidural intraespinal. Assinala-se sua maior freqüência entre homens com mais de 50 anos, embora pacientes mais jovens possam ser acometidos, principalmente entre 15 e 29 anos. A distribuição segmentar dos tumores permite um diagnóstico diferencial, sendo a região torácica a sede mais freqüentes de sarcomas. O principal sintoma encontrado nos pacientes com reticulossarcoma foi a dor, do tipo radicular, que serve para diferenciar os tumores intra e extra-medulares, tendo sido de aparecimento precoce em 15 dos pacientes estudados, precedendo em muitos meses e até anos os demais sintomas. Classificou-se os tumores reticulohistiocitários epidurais do canal vertebral em três grupos, de acordo com seu aspecto tecidual e celular e, principalmente, com a presença e distribuição da reticulina. Relacionou-se o tempo de evolução desses tumores com seu aspecto histopatológico, chegando-se à conclusão que os tumores classificados no grupo III apresentam um período evolutivo maior que os demais, o que nos levou a pensar que crescem mais lentamente, apresentando, portanto, melhor prognóstico que os demais tipos, muito embora todos os tipos de reticulossarcomas possam apresentar um prognóstico mais favorável quando precocemente diagnosticados e tratados adequadamente.

  11. Estudos sobre a Esquistosomose em Pernambuco, Brasil

    Aggeu Magalhães


    Full Text Available Os autores referem os resultados dos estudos sobre esquistosomose realisados, em Pernambuco, de Novembro de 1938 a Dezembro de 1939. Não se extendem em discussão, nem comentarios, tampouco, relacionam suas verificações com o que já foi relatado sobre o assunto em trabalhos nacionais e estrangeiros, pelo fato de que, não se trata de um resultado definitivo e sim de atividades que irão proseguir. Os estudos sistematicos em torno da endemia esquistosomica foram executados em duas localidades diversas pela população e pela situação geografica e ecologica. Pontezinha é uma povoação de 1200 habitantes localizada proximo a um conjunto de charcos e lagõas de agua dôce onde pululam caramujos do tipo olivaceus de Spix, e apresenta uma taxa de infestação de 21,4% para individuos do sexo masculino, e de 14,7% para os do sexo feminino. A distribuição por grupos de idade mostra que a incidencia cresce até o grupo de 16 a 20 anos de idade, quando atinge a percentagem de 37,8%, para decrescer em seguida. Em Vitoria a incidencia foi maior nos indivíduos do sexo feminino, atingindo a taxa de 41,4%, dando o sexo masculino a taxa de 36,9%. Por idade a percentagem maxima é atingida pelo grupo de 11 a 15 anos. Vitoria é uma cidade de 1500 habitantes, construida á margem do rio Tapacurá, onde se encontram numerosos caramujos do tipo centimetralis Lutz. A divergencia de incidencia corre por conta dos habitos da população e pela utilização que ela faz do rio, sendo maior em Vitoria porque a proximidade do rio facilita o uso de suas aguas para banho e serviços domesticos, condicionando este ultimo fato, a maior infestação das mulheres. O estudo da frequencia da infestação dos caramujos por cercarias de diversos trematodios, permite suspeitar uma relação inversa entre a taxa de infestação e o diametro maximo atingido pelos caramujos, parecendo este fato confirmar os trabalhos de Vianna Martins sobre a identidade dos hospedeiros

  12. High power lasers & systems

    Chatwin, Chris; Young, Rupert; Birch, Philip


    Some laser history;\\ud Airborne Laser Testbed & Chemical Oxygen Iodine Laser (COIL);\\ud Laser modes and beam propagation;\\ud Fibre lasers and applications;\\ud US Navy Laser system – NRL 33kW fibre laser;\\ud Lockheed Martin 30kW fibre laser;\\ud Conclusions

  13. Comparative study in swines' vocal cords healing after excision of fragment with CO2 laser with mitomycin and 5-fluorouracil postoperative topical application Estudo comparado da cicatrização da prega vocal de suínos após exérese de fragmento com laser de CO2 e aplicação tópica pós-operatória de mitomicina e 5-fluorouracil

    Eduardo Baptistella


    Full Text Available PURPOSE: To evaluate the deposition of collagen fibers at pig's vocal folds after topical use of mitomycin or 5-fluorouracil, when partial exeresis of mucosa layer had been promoted by CO2 laser. METHODS: There were used 18 Larger white pigs which were anesthetized and submitted to mucosa fragment's exeresis, bilaterally, at its free border. The animals were divided into 3 groups, each one with 6 animals: control group, without topical drug application; mitomycin group; and 5-fluorouracil group. After 30 days, the animals were subjected to euthanasia, and samples of the vocal folds were collected and stained by picrosirius red technique with polarization for quantification of total collagen deposition. RESULTS: In control group, the mean rate of right vocal fold's collagen deposition at submucosa consisted in a 3428.66 micrometers area. There was found an area whose size had, in average, 2196.36 micrometers, in mitomycin group, and 2269.19 micrometers, in 5-fluorouracil group. CONCLUSION: Mitomycin and 5-fluorouracil had promoted beneficial change in vocal fold's cicatrization with less collagen deposition, but there was no significant statistically difference when they were compared between themselves.OBJETIVO: Avaliar a deposição das fibras de colágeno total em pregas vocais suínas após o uso tópico de mitomicina ou 5-fluorouracil nas exéreses parciais de mucosa com laser de CO2. MÉTODOS: Foram utilizados 18 porcos da raça Larger white anestesiados e submetidos à exérese de fragmento de mucosa de borda livre da prega vocal direita e prega vocal esquerda. Os animais foram divididos em 3 grupos com 6 animais cada: grupo controle, sem aplicação de medicação tópica; grupo mitomicina, com uso tópico dessa substância; grupo 5-fluorouracil, uso tópico. Após 30 dias do experimento os animais foram submetidos à eutanásia, coletadas amostras das pregas vocais e coradas pela técnica do picrosirius red com polarização para a

  14. Estudos organizacionais, (descolonialidade e estudos da dependência: as contribuições da Cepal

    Sergio Wanderley

    Full Text Available O objetivo deste artigo é (revisitar o conceito de dependência como categoria de investigação da (e a partir da América Latina, por meio de uma perspectiva histórica crítica descolonial, a fim de ampliar o espaço de debates em estudos organizacionais e promover alternativas à ordem neoliberal. Este ensaio terá como foco os estudos da dependência realizados pela Comissão Econômica para a América Latina e o Caribe (Cepal durante a década de 1950 e o início dos anos 1960. A perspectiva descolonial é um constructo teórico de autores latino-americanos que se consideram herdeiros da longa tradição do pensamento social crítico da região, na qual a teoria da dependência está inserida. As propostas dos autores da dependência confrontaram as principais teorias ortodoxas do Norte produzidas à época. A partir do conceito de centro-periferia, da denúncia de assimetrias nas relações entre essas regiões, do reconhecimento da interdependência entre desenvolvimento e subdesenvolvimento, o conceito de dependência foi sendo (reelaborado nas décadas de 1950 e 1960 por diversos autores latino-americanos como uma categoria de investigação da realidade da (e a partir da região. Essas investigações tinham por objetivo não somente elaborar constructos teóricos, mas, também, transformar a realidade por meio da criação de diversas organizações e instituições que deveriam servir ao propósito de superar o subdesenvolvimento. A denúncia da historicidade da situação de subdesenvolvimento desnudou o caráter de neutralidade do economicismo das teorias produzidas no Norte e promoveu um encontro teórico entre economia e política que muito tem a contribuir com a área dos estudos organizacionais.

  15. Laser yellowing

    M B Sai Prasad; Salvatore Siano


    Over the past few years there has been an increasing interest in researches related to the application of lasers in conservation, analysis and diagnostics of artwork surfaces. Among the many interesting problems to be tackled, one issue was drawing more interest because of the limitations it can impose on the use of lasers. Laser yellowing is a phenomenon wherein artwork surfaces assume a yellow hue when cleaned with Q-switched Nd:YAG (1064 nm) lasers in particular. Here the effect of yellowing has been studied and quantified for artwork surfaces (marble) using SFR Nd:YAG and LQS Nd:YAG lasers. Colorimetric measurements by employing a spectroradiometer helps to quantify the effect of yellowing by analysing three variables (chromaticity coordinates) of interest.


    Alfredo LAM-SÁNCHEZ


    Full Text Available

    RESUMO: Estudos com arroz (Oryza sativa, L. foram realizados a fim de determinar a variabilidade do teor de proteína em coleções de cultivares e a possibilidade de utilizar as camadas periféricas do grão na alimentação humana. Foram analisadas 626 linhagens e cultivares de arroz que mostraram uma variação quanto ao teor de proteína de 4.00 a 14.31 g/100 g de amostra. Para se extrair as camadas periféricas do grão, foi desenvolvida uma máquina experimental, que removia as camadas superficiais dos grãos de arroz integral (inteiros somente com a casca removida. Verificou-se que a quantidade de proteína do grão diminui de fora para dentro. O resíduo, que era constituído de grande parte de restos de endosperma com um teor protéico menor mas incluía o embrião, que é a primeira estrutura a se deslocar de grão no beneficiamento e contém proteínas, vitaminas, sais minerais e lípides, tinha um bom valor nutritivo. Desenvolveu-se também uma fórmula para alimentação infantil a partir da mistura de leite de vaca com arroz, com composição semelhante à do leite materno, a ser utilizada sob a forma de bebida ou mingau. Formulações com 40%-20% arroz + 60%-80% leite de vaca proporcionaram valores de Coeficiente de Eficiência Protéica (2,39 e 2,38, respectivamente que não diferiam estatisticamente do valor de 2,43 obtido na fórmula com 100% de leite de vaca. Seus preços foram 59% e 65% do obtido para o leite de vaca integral. PALAVRAS-CHAVE: Arroz; qualidade do grão; proteína; camadas periféricas; misturas arroz-leite; nutrição humana.

  17. Estudo de caso: disfonia psicogênica

    Marcela Bergamini


    Full Text Available Disfonia funcional psicogênica possui relação com aspectos psicológicos. O tipo de voz, a articulação e a fluência são sensíveis às oscilações psicológicas. Uma voz em ajuste de falsete paralítico, caracterizada como uma voz de pitch extremamente agudo pode ser encontrada em casos de disfonias psicogênicas. Em qualquer quadro psicogênico é essencial um diagnóstico diferencial, a fim de viabilizar um tratamento fonoaudiológico e médico adequados e efetivos. O prognóstico de uma alteração psicogênica geralmente é bom. O quadro de disfonia psicogênica é mais comum no sexo feminino. O objetivo desse estudo é apresentar a evolução terapêutica de um indivíduo com disfonia psicogênica. A.J.O., 45 anos, sexo masculino, compareceu ao Ambulatório de Avaliação e Terapia de Voz encaminhado por médico otorrinolaringologista. Trouxe a queixa vocal "pela manhã a voz está perfeita, conforme o dia passa, a voz fica fina". Realizou avaliação fonoaudiológica em 18 de abril de 2013, com laudo médico de "mobilidade reduzida de prega vocal esquerda". Tratamento com técnica de sons disparadores, com modificação direta nos sintomas e evolução rápida. Demonstrou-se satisfeito com sua qualidade vocal. Em casos de suspeita de disfonias psicogênicas de conversão, devem-se descartar alterações orgânicas, sendo essencial uma avaliação fonoaudiológica que auxilie no diagnóstico diferencial e provas terapêuticas que incentivem o paciente.

  18. High throughput laser processing

    Harley, Gabriel; Pass, Thomas; Cousins, Peter John; Viatella, John


    A solar cell is formed using a solar cell ablation system. The ablation system includes a single laser source and several laser scanners. The laser scanners include a master laser scanner, with the rest of the laser scanners being slaved to the master laser scanner. A laser beam from the laser source is split into several laser beams, with the laser beams being scanned onto corresponding wafers using the laser scanners in accordance with one or more patterns. The laser beams may be scanned on the wafers using the same or different power levels of the laser source.

  19. Optical and electrical characteristics of chromium- and iron-doped zinc selenide thin film and bulk materials for optically and electrically pumped lasers

    Gallian, Andrew

    This work is devoted to evaluating new laser systems based upon chromium and iron doped ZnSe structures. These systems are based upon new materials and pumping schemes. These topics can be broken down into three major subgroups: new materials based upon Cr2+:ZnSe, Fe2+:ZnSe lasers and pump sources, and electrically pumped Cr2+:ZnSe systems. Both hot-pressed ceramic and thin film Cr2+:ZnSe samples were evaluated for their potential as laser gain media. This work entailed spectroscopic analysis of both their absorption and emission spectra as well as characterizing their lifetime of luminescence. For hot-pressed ceramic Cr2+:ZnSe the samples were tested in a laser cavity and proven to be the first laser system in the mid-IR to be demonstrated based upon hot-pressed Cr2+:ZnSe. Thin film Cr2+:ZnSe was determined to have different spectroscopic characteristics for luminescence compared to reference bulk samples. This difference is attributed to the location of all of the optical centers within a Fabry-Perot cavity formed by the film surface and the wafer on which it was deposited. Fe2+:ZnSe laser demonstration at room temperature is presented. This laser operates in a spectral region of great interest for spectroscopy. To develop this laser system new pumping systems were required. Such systems as passively Q-switched Er:YSGG and Stokes Stimulated Raman Scattering from a D2 cell are described in great depth. Electrically pumped Transition Metal 2+:II-VI systems are ideal for small portable spectroscopic and scientific tools. The elimination of an optical pump source removes many complications of other systems including, complications due to having a second laser. This work was approached by modeling electrically motivated transitions with sub-band optical excitation. Lasing of Cr 2+:ZnSe was achieved using a 532 nm pump source. This result, in combination with photo-current and photo-Hall measurements, led to the development of some theories explaining possible

  20. Uma ferramenta para planejamento de estudos para concursos

    Leonardo Pimentel


    Full Text Available De acordo com a constituição brasileira, a única forma de se tornar um empregado do governo é passar em um concurso público. O exame de conhecimento do cargo é um dos componentes mais importantes de um concurso. Estudar para esse exame é uma tarefa que requer planejamento. Um meio de obter um bom planejamento é construir uma grade de horários que relacione as matérias a serem estudadas com os respectivos horários disponíveis para o estudo. Esse tipo de problema se assemelha bastante à gerência de projetos, em que se procura estabelecer a distribuição das atividades ao longo do tempo disponível. Assim, torna-se interessante explorar a dinâmica de estudos para concursos como um projeto. O presente trabalho apresenta a ferramenta de apoio ao estudos - Passe-me, baseada no ciclo PDCA (do inglês, Plan-Do-Check-Act. Por se tratar de uma ferramenta web, o tempo de resposta para produzir uma grade de estudos é fundamental. A ferramenta faz uso de algoritmo genético para calcular a grade de horários priorizando a velocidade de resposta. A ferramenta foi avaliada em diferentes cenários de uso e obteve desempenho satisfatório durante a produção da grade de estudos.

  1. [Lipolysis lasers].

    Mazer, J-M


    We use lipolysis lasers for around five years. The principle of those lasers is that, for some wavelengths, the fat, located in the adipocytes reacts as a chromophor. In order to allow the direct exposure of the adipocytes to the optical fiber (around 1mm diameter), this has to be inserted in the hypodermis, then move back and forth inside the treated areas. The theorical benefits, compared to the liposuction procedures are related to the fact that the thermal effect of the laser emission allows to avoid laxity, sometimes observed after a liposuction. If we consider the first publications related to this emerging procedure, the profile of tolerance seems good, and even possibly better than the liposuctions. Nevertheless, this procedure with lasers is still a surgical procedure, exposing theorically to the side effects related in and after each surgery: infections, ecchymosis... Recently, some cases of severe side effects (infection of the skin, and necrosis) have been reported. They seem to be related to a homogeneous distribution of the energy inducing an excessive thermal injury. Some new improvements, with the last generation lasers, could allow us to avoid, or at least to dramatically reduce those side effects. The efficacy of those lasers is visibly satisfying; the key question is to precise the optimal modalities of use : in a surgery room, after an optimal training, with the last generation lasers?

  2. Laser spectroscopy

    Demtröder, Wolfgang


    Keeping abreast of the latest techniques and applications, this new edition of the standard reference and graduate text on laser spectroscopy has been completely revised and expanded. While the general concept is unchanged, the new edition features a broad array of new material, e.g., frequency doubling in external cavities, reliable cw-parametric oscillators, tunable narrow-band UV sources, more sensitive detection techniques, tunable femtosecond and sub-femtosecond lasers (X-ray region and the attosecond range), control of atomic and molecular excitations, frequency combs able to synchronize independent femtosecond lasers, coherent matter waves, and still more applications in chemical analysis, medical diagnostics, and engineering.

  3. Laser spectroscopy

    Demtröder, Wolfgang

    Keeping abreast of the latest techniques and applications, this new edition of the standard reference and graduate text on laser spectroscopy has been completely revised and expanded. While the general concept is unchanged, the new edition features a broad array of new material, e.g., ultrafast lasers (atto- and femto-second lasers) and parametric oscillators, coherent matter waves, Doppler-free Fourier spectroscopy with optical frequency combs, interference spectroscopy, quantum optics, the interferometric detection of gravitational waves and still more applications in chemical analysis, medical diagnostics, and engineering.

  4. Semiconductor laser

    Ito, K.; Shyuue, M.


    A distributed feedback semiconductor laser is proposed which generates several beams with equal wavelengths in different directions. For this purpose, 1 millimeter grooves are cut into the surface of an n-type conductance GaAs plate in three different directions; these grooves form a diffraction grating. The center of this plate has no grooves and is bombarded by an He/Ne laser beam. The diffraction gratings provide resonance properties and generate laser beams with wavelengths of 8850, 9000 and 9200 angstroms.

  5. Desenvolvimento da Tanatologia: estudos sobre a morte e o morrer

    Maria Julia Kovács


    Full Text Available Este artigo discute os principais temas e pesquisas na área da Tanatologia, estudos sobre a morte e o morrer. São apresentados os autores pioneiros que escreveram as primeiras obras de sistematização da Tanatologia entre os quais: Herman Feifel, Robert Kastenbaum e Elizabeth Kübler-Ross, e os principais temas de estudo: luto, violência e guerra, a morte e a TV, cuidados a pacientes gravemente enfermos, além da formação de profissionais da área de saúde e educação para lidar com pessoas vivendo situações de perdas e morte. São feitas propostas de estudos para o futuro desenvolvimento da Tanatologia em nosso país.


    Maria José da Silva Feitosa


    Full Text Available Nos últimos anos intensificaram-se os estudos referentes às bases do comprometimento organizacional, contempladas no modelo Meyer e Allen. Nessa perfectiva, o presente estudo objetiva verificar as bases afetiva, normativa e instrumental em duas empresas de consultoria. Para tanto, foi realizada uma pesquisa descritiva, de abordagem quantitativa. Os resultados apontam que a base afetiva se destacou em ambas as empresas, tanto em uma análise por gênero, quanto em uma perspectiva geral. Esse resultado pode estar relacionado à possibilidade de que os estudantes que ingressam em empresas juniores se entusiasmem com a oportunidade de aplicar seus conhecimentos e se comprometam de forma afetiva com a organização. No entanto, para testar essa relação sugere-se a realização de novos estudos.

  7. Laser Refractography

    Rinkevichyus, B.S; Raskovskaya, I.L


    This book describes the basic principles of laser refractography, a flexible new diagnostic tool for measuring optically inhomogeneous media and flows. Laser refractography is based on digital imaging and computer processing of structured laser beam refraction (SLR) in inhomogeneous transparent media. Laser refractograms provide both qualitative and quantitative measurements and can be used for the study of fast and transient processes. In this book, the theoretical basis of refractography is explored in some detail, and experimental setups are described for measurement of transparent media using either 2D (passed radiation) or 3D (scattered radiation) refractograms. Specific examples and applications are discussed, including visualization of the boundary layer near a hot or cold metallic ball in water, and observation of edge effects and microlayers in liquids and gases. As the first book to describe this new and exciting technique, this monograph has broad cross-disciplinary appeal and will be of interest t...

  8. Laser Dentistry

    ... whitening procedures. What are the benefits of using dental lasers? There are several advantages. Dentists may not need to use a drill or administer anesthesia in some procedures, allowing the patient to enjoy ...

  9. Laser Optomechanics

    Yang, Weijian; Ng, Kar Wei; Rao, Yi; Chase, Christopher; Chang-Hasnain, Connie J


    Cavity optomechanics explores the coupling between the optical field and the mechanical oscillation to induce cooling and regenerative oscillation in a mechanical oscillator. So far, optomechanics relies on the detuning between the cavity and an external pump laser, where the laser acts only as a power supply. Here, we report a new scheme with mutual coupling between a mechanical oscillator that supports a mirror of a vertical-cavity surface-emitting laser (VCSEL) and the optical field, greatly enhancing the light-matter energy transfer. In this work, we used an ultra-light-weight (130 pg) high-contrast-grating (HCG) mirror in a VCSEL, whose reflectivity spectrum is designed to facilitate strong optomechanical coupling, to demonstrate optomechanically-induced regenerative oscillation of the laser optomechanical cavity with > 550 nm self-oscillation amplitude of the micro-mechanical oscillator, two to three orders of magnitude larger than typical. This new scheme not only offers an efficient approach for high-...

  10. Il laser

    Smith, William V


    Verso il 1960, il laser era ancora "una soluzione alla ricerca di un problema", ma fin dagli anni immediatamente successivi si è rivelato uno strumento insostituibile per le applicazioni più svariate.

  11. [Laser myringotomy].

    Hassmann-Poznańska, Elzbieta; Skotnicka, Bozena


    The aim of the study was assessment of the qualities of laser-assisted myringotomy (LAM) as a treatment for acute and secretory otitis media. Laser-assisted myringotomy was performed on 65 children (113 ears) mean age 6.2 years diagnosed with secretory otitis media (80%), recurrent secretory otitis media (11%) and acute otitis media (9%). Myringotomy was performed under general anesthesia using the OtoLAM device (ESC/Sharplan, Israel). In 64 ears pressure equalisation tubes were inserted after fenestration of the tympanic membrane with laser. Adenoidectomy alone or with tonsillectomy was performed at the same time in 51 cases. Laser tympanostomies remained patent for 7-32 days. All tympanostomies healed with no noticeable scarring. LAM appears to be a safe, and easy to performed, alternative technique in the treatment of otitis media.

  12. A laser

    Togo, N.


    It is reported that an improved laser design employing pumping of the active gas medium has been developed. A diagram of the laser system is given and its principle of operation is described in detail. Gas pumping is achieved using a pump whose oil reservoir is sealed by a sealing element. When the sealing element fails, the oil from the reservoir pollutes the laser substance. It is proposed that an additional oil reservoir pumping loop be used to maintain a lower pressure. The reservoir pressure is recorded by a sensor. When the sealing element fails, the pressure in the reservoir increases. The sensor records the change in pressure and generates a signal which shuts down the laser system. Thus, the possibility for oil penetration into the gas system is totally eliminated.

  13. Green lasers

    Jensen, Ole Bjarlin


    Well over a dozen papers at this year's Photonics West meeting in San Francisco boasted improvements in harmonic generation to produce visible laser beams, most of them in the green spectral range......Well over a dozen papers at this year's Photonics West meeting in San Francisco boasted improvements in harmonic generation to produce visible laser beams, most of them in the green spectral range...

  14. Green lasers

    Jensen, Ole Bjarlin


    Well over a dozen papers at this year's Photonics West meeting in San Francisco boasted improvements in harmonic generation to produce visible laser beams, most of them in the green spectral range......Well over a dozen papers at this year's Photonics West meeting in San Francisco boasted improvements in harmonic generation to produce visible laser beams, most of them in the green spectral range...

  15. Desenvolvimento da Tanatologia: estudos sobre a morte e o morrer

    Maria Julia Kovács


    Este artigo discute os principais temas e pesquisas na área da Tanatologia, estudos sobre a morte e o morrer. São apresentados os autores pioneiros que escreveram as primeiras obras de sistematização da Tanatologia entre os quais: Herman Feifel, Robert Kastenbaum e Elizabeth Kübler-Ross, e os principais temas de estudo: luto, violência e guerra, a morte e a TV, cuidados a pacientes gravemente enfermos, além da formação de profissionais da área de saúde e educação para lidar com pessoas vivend...

  16. Estudo patográfico de Fernando Pessoa


    Fernando Pessoa, incontestavelmente um dos maiores gênios da literatura universal, é objeto deste estudo patográfico. Através da análise de sua biografia e obra, os autores buscam delinear seus perfis psicológico e psicopatológico e caracterizar uma associação entre sua evidente bipolaridade e seu padrão criativo. Os dados do estudo revelam claramente um componente bipolar e sugerem haver influência de seu humor de base sobre a atividade literária, quanto ao conteúdo, número de po...

  17. Desenvolvimento da Tanatologia: estudos sobre a morte e o morrer

    Maria Julia Kovács


    Este artigo discute os principais temas e pesquisas na área da Tanatologia, estudos sobre a morte e o morrer. São apresentados os autores pioneiros que escreveram as primeiras obras de sistematização da Tanatologia entre os quais: Herman Feifel, Robert Kastenbaum e Elizabeth Kübler-Ross, e os principais temas de estudo: luto, violência e guerra, a morte e a TV, cuidados a pacientes gravemente enfermos, além da formação de profissionais da área de saúde e educação para lidar com pessoas vivend...

  18. Laser Physics and Laser Techniques


    Other types of laser-assisted materials process- Planck Institute for Quantum Optics. Garching . West ing and machining, including laser cutting, welding...detectors with microstructured electrodes, 134[ G. N. Maracas. G. L. Harrs, C. A. Lee. and R. A. McFarlane. Opt. Le’tt., vol. 7, pp. 575-577, Dcc . 1982...A. E. Siegman Max-Planck Institut f’r Quantenoptik, D-8046 Garching , West Germany and E. L. Ginzton Laboratory, Stanford University, Stanford

  19. Laser therapy for cancer

    ... this page: // Laser therapy for cancer To use the sharing features ... Lasers are also used on the skin. How Laser Therapy is Used Laser therapy can be used ...

  20. Propostas para o estudo dos protestantismos ibéricos

    Afonso, José António


    A propósito da edição da obra “Las minorias religiosas en España y Portugal: passado y presente”, número monográfico da revista “Anales de Historia Contemporanea” (Universidade de Múrcia), o Autor elenca algumas propostas para o estudo dos protestantismos ibéricos.


    Felipe Antunes


    Full Text Available Este artigo aborda a qualidade e acreditação hospitalar através do Manual das Organizações Prestadoras de Serviços Hospitalares, desenvolvido pela Organização Nacional de Acreditação (ONA. O objetivo geral deste trabalho é avaliar o processo de acreditação, identificando dificuldades e benefícios advindos da implantação deste  Manual. Após a realização de uma revisão bibliográfica sobre qualidade em hospitais e normas da qualidade aplicáveis a hospitais, é feita uma análise crítica teórica do Manual das Organizações Prestadoras de Serviços Hospitalares. Tal análise crítica inclui um estudo comparativo entre os requisitos do Manual e da norma NBR ISO 9001/2000. A seguir, a análise teórica é complementada através de um estudo de caso contemplando a implantação do Manual junto a um hospital de grande porte. Finalmente, são apresentadas as conclusões, baseadas tanto no estudo teórico como no estudo prático.

  2. Pragmatismo e os pragmáticos nos estudos organizacionais

    Francis Kanashiro Meneghetti

    Full Text Available O objetivo central deste ensaio teórico é avaliar as contribuições do pragmatismo nos Estudos Organizacionais e, os específicos, avaliar se as contribuições teóricas de Charles Peirce e John Dewey possibilitam afirmar o pragmatismo como senso comum, ciência ou teoria do conhecimento; analisar as contribuições - possibilidadese limites - do pragmatismo como conhecimento científico; compreender os percursos do pragmatismo nos Estudos Organizacionais. Chaga-se a conclusão de que ser pragmático é diferente de conceber estudos articulados no campo epistemológico do pragmatismo. O sujeito pragmático vê na sua utilidade e na necessidade deação, o ponto de tensão que coloca em dúvida a veracidade dos pressupostos do pragmatismo como ciência. O que ocorre nos Estudos Organizacionais éa conversão do pragmatismo como conhecimento científico emsubordinação irracional à utilidade e à ação prática, sobretudo, no campo da economia, da política, da ciência, da cultura, da educação, e assim por diante.

  3. Laser acceleration

    Tajima, T.; Nakajima, K.; Mourou, G.


    The fundamental idea of Laser Wakefield Acceleration (LWFA) is reviewed. An ultrafast intense laser pulse drives coherent wakefield with a relativistic amplitude robustly supported by the plasma. While the large amplitude of wakefields involves collective resonant oscillations of the eigenmode of the entire plasma electrons, the wake phase velocity ˜ c and ultrafastness of the laser pulse introduce the wake stability and rigidity. A large number of worldwide experiments show a rapid progress of this concept realization toward both the high-energy accelerator prospect and broad applications. The strong interest in this has been spurring and stimulating novel laser technologies, including the Chirped Pulse Amplification, the Thin Film Compression, the Coherent Amplification Network, and the Relativistic Mirror Compression. These in turn have created a conglomerate of novel science and technology with LWFA to form a new genre of high field science with many parameters of merit in this field increasing exponentially lately. This science has triggered a number of worldwide research centers and initiatives. Associated physics of ion acceleration, X-ray generation, and astrophysical processes of ultrahigh energy cosmic rays are reviewed. Applications such as X-ray free electron laser, cancer therapy, and radioisotope production etc. are considered. A new avenue of LWFA using nanomaterials is also emerging.

  4. Header For Laser Diode

    Rall, Jonathan A. R.; Spadin, Paul L.


    Header designed to contain laser diode. Output combined incoherently with outputs of other laser diodes in grating laser-beam combiner in optical communication system. Provides electrical connections to laser diode, cooling to thermally stabilize laser operation, and optomechanical adjustments that steer and focus laser beam. Range of adjustments provides for correction of worst-case decentering and defocusing of laser beam encountered with laser diodes. Mechanical configuration made simple to promote stability and keep cost low.

  5. Dyestuff laser

    Brinkmann, U.; Raue, R.; Schellhammer, C.; Telle, H.


    Laser light in the wavelength range of 400 - 480 nm is obtained with a dyestuff laser containing a dyestuff of the general formula wherein E denotes one of the radicals R1-R4 independently of one another denote hydrogen, alkyl, trifluoromethyl, alkoxy, aralkoxy, halogen, alkenyloxy, the carboxyl, cyano, alkylsulphone, arylsulphone, carboxamide or sulphonamide group or the carboxylic acid ester group, or R1 and R2, or R3 and R4, conjointly represent a fused benzene ring and M and N independently of one another denote 0, 1 or 2, with the proviso that the radical E contains at least one sulphonic acid group if M and N represent 0, and wherein the radical E can be further substituted, in a solvent which does not interfere with the emission, at a concentration, which emits laser beams, of, preferably, 10-2 to 10-5 mols/liter.

  6. A laser

    Togo, N.


    The development of an improved gas laser system employing pumping of the active gaseous medium is reported. The layout of the design is given and its principle of operation is described in detail. The oil reservoir in the vacuum pump which pumps the gas through the laser system is separated by a sealing element; when this element fails, the oil may pollute the active medium. It is proposed that an additional oil reservoir pumping loop be used with the pump that operates continuously and maintains a lower pressure in the reservoir. The pressure in the reservoir is monitored by a special sensor. When the sealing element fails, the pressure sensor records the pressure drop in the oil reservoir. A signal is then generated and the laser system ceases operation, and eliminates the possibility for the oil penetrating into the pumping system.

  7. Therapeutic laser for pain relief after tonsillectomy

    Felipe Costa Neiva; Vieira,Fernando Mirage J.; Claudia Regina Figueiredo; Aldo Eden C. Stamm; Weckx,Luc Louis M.; Pignatari,Shirley Shizue N.


    OBJETIVO: O pós-operatório da tonsilectomia é, em geral, bastante doloroso e os pacientes necessitam de analgésicos. Este estudo visou avaliar a eficácia da aplicação do laser terapêutico no controle da dor no pós-operatório de tonsilectomia. MÉTODOS: 18 crianças de cinco a 15 anos de idade foram submetidas à adenotonsilectomia, no período de junho de 2005 a outubro de 2006, sendo randomizadas para receber aplicações de laser terapêutico na área cirúrgica imediatamente após o procedimento e 2...

  8. Laser barometer

    Abercrombie, Kevin R.; Shiels, David; Rash, Tim


    A pressure measuring instrument that utilizes the change of the refractive index of a gas as a function of pressure and the coherent nature of a laser light to determine the barometric pressure within an environment. As the gas pressure in a closed environment varies, the index of refraction of the gas changes. The amount of change is a function of the gas pressure. By illuminating the gas with a laser light source, causing the wavelength of the light to change, pressure can be quantified by measuring the shift in fringes (alternating light and dark bands produced when coherent light is mixed) in an interferometer.

  9. Laser Heterodyning

    Protopopov, Vladimir V


    Laser heterodyning is now a widespread optical technique, based on interference of two waves with slightly different frequencies within the sensitive area of a photo-detector. Its unique feature – preserving phase information about optical wave in the electrical signal of the photo-detector – finds numerous applications in various domains of applied optics and optoelectronics: in spectroscopy, polarimetry, radiometry, laser radars and Lidars, microscopy and other areas. The reader may be surprised by a variety of disciplines that this book covers and satisfied by detailed explanation of the phenomena. Very well illustrated, this book will be helpful for researches, postgraduates and students, working in applied optics.

  10. Laser device


    The present invention provides a light source for light circuits on a silicon platform. A vertical laser cavity is formed by a gain region arranged between a first mirror structure and a second mirror structure, both acting as mirrors, by forming a grating region including an active material...

  11. Laser diagnodent: a comparative study with other diagnostic techniques; Laser diagnodent: estudo comparativo com outras tecnicas de diagnostico

    Godinho, Reugma Rego


    An evaluation of the Diagnodent equipment (Kavo Company, Germany) for the occlusal caries detection was dane through the comparison with other conventional diagnostic techniques, such as visual inspection, intra-oral micro camera and digital X-ray. The effectiveness of the equipment in the detection of hidden caries and its viability as a diagnosis method for caries in their initial stage was also studied. Fifty eight permanent molars and premolars teeth from patients with age between 6 and 30 years were studied. The obtained results indicated that the conventional methods employed for the caries diagnosis are unable to detect the carious lesion in its initial stage. The Diagnodent equipment has this capability to detect caries presenting a flawless surface, specially the hidden caries, allowing the dentist to decide between a preventive ar a conservative procedure. The main advantage of the Diagnodent is to be an objective method, compared to the visual and radiographic ones, that are dependent on the professional interpretation. The Diagnodent is, therefore, a promising alternative as an objective and standardized diagnosis method for the final diagnostic. (author)

  12. Contribuição para o estudo da versão portuguesa da Positive and Negative Affect Schedule (PANAS): II – Estudo psicométrico


    Estudo da adaptação da Positive and Negative Affect Schedule (PANAS; Watson, Clark & Tellegen, 1988) para a população portuguesa. A metodologia do estudo procurou replicar o estudo de desenvolvimento da escala original. Tal como o estudo original, pediu-se a 348 estudantes universitários que respondessem em que medida experienciaram as 60 emoções (traduzidas para Português) propostas por Zevon e Tellegen (1982) “durante os últimos dias” e “durante as últimas semanas”, numa escala de 5 pontos....

  13. Nanowire Lasers

    Couteau, C.; Larrue, A.; Wilhelm, C.; Soci, C.


    We review principles and trends in the use of semiconductor nanowires as gain media for stimulated emission and lasing. Semiconductor nanowires have recently been widely studied for use in integrated optoelectronic devices, such as light-emitting diodes (LEDs), solar cells, and transistors. Intensive research has also been conducted in the use of nanowires for subwavelength laser systems that take advantage of their quasione- dimensional (1D) nature, flexibility in material choice and combination, and intrinsic optoelectronic properties. First, we provide an overview on using quasi-1D nanowire systems to realize subwavelength lasers with efficient, directional, and low-threshold emission. We then describe the state of the art for nanowire lasers in terms of materials, geometry, andwavelength tunability.Next,we present the basics of lasing in semiconductor nanowires, define the key parameters for stimulated emission, and introduce the properties of nanowires. We then review advanced nanowire laser designs from the literature. Finally, we present interesting perspectives for low-threshold nanoscale light sources and optical interconnects. We intend to illustrate the potential of nanolasers inmany applications, such as nanophotonic devices that integrate electronics and photonics for next-generation optoelectronic devices. For instance, these building blocks for nanoscale photonics can be used for data storage and biomedical applications when coupled to on-chip characterization tools. These nanoscale monochromatic laser light sources promise breakthroughs in nanophotonics, as they can operate at room temperature, can potentially be electrically driven, and can yield a better understanding of intrinsic nanomaterial properties and surface-state effects in lowdimensional semiconductor systems.

  14. Nanowire Lasers

    Couteau C.


    Full Text Available We review principles and trends in the use of semiconductor nanowires as gain media for stimulated emission and lasing. Semiconductor nanowires have recently been widely studied for use in integrated optoelectronic devices, such as light-emitting diodes (LEDs, solar cells, and transistors. Intensive research has also been conducted in the use of nanowires for subwavelength laser systems that take advantage of their quasione- dimensional (1D nature, flexibility in material choice and combination, and intrinsic optoelectronic properties. First, we provide an overview on using quasi-1D nanowire systems to realize subwavelength lasers with efficient, directional, and low-threshold emission. We then describe the state of the art for nanowire lasers in terms of materials, geometry, andwavelength tunability.Next,we present the basics of lasing in semiconductor nanowires, define the key parameters for stimulated emission, and introduce the properties of nanowires. We then review advanced nanowire laser designs from the literature. Finally, we present interesting perspectives for low-threshold nanoscale light sources and optical interconnects. We intend to illustrate the potential of nanolasers inmany applications, such as nanophotonic devices that integrate electronics and photonics for next-generation optoelectronic devices. For instance, these building blocks for nanoscale photonics can be used for data storage and biomedical applications when coupled to on-chip characterization tools. These nanoscale monochromatic laser light sources promise breakthroughs in nanophotonics, as they can operate at room temperature, can potentially be electrically driven, and can yield a better understanding of intrinsic nanomaterial properties and surface-state effects in lowdimensional semiconductor systems.

  15. Excimer Laser Technology

    Basting, Dirk


    This comprehensive survey on Excimer Lasers investigates the current range of the technology, applications and devices of this commonly used laser source, as well as the future of new technologies, such as F2 laser technology. Additional chapters on optics, devices and laser systems complete this compact handbook. A must read for laser technology students, process application researchers, engineers or anyone interested in excimer laser technology. An effective and understandable introduction to the current and future status of excimer laser technology.

  16. Estudos da formação de planetas terrestres

    Costa, André Izidoro Ferreira da [UNESP


    O estudo da formação de planetas terrestres no Sistema Solar, é crucial para compre- endermos como outros sistemas planetários formam e também inferir as condições que poderiam ter influenciado a origem e evolução de vida na Terra. Esta Tese de douto- rado apresenta um estudo numérico da formação de planetas terrestres. Nosso objetivo principal é analisar o último estágio da formação desses planetas no Sistema Solar, em particular, a formação de Marte e a origem da água da Terra. Esses dois p...

  17. Influência do uso do laser na prevenção da cárie radicular

    Cesar Penazzo Lepri


    Objetivo: Este estudo avaliou a influência do uso de diferentes lasers, associados ou não à aplicação de fluoreto de sódio, na prevenção da cárie radicular. Materiais e Método: Para este estudo, 128 espécimes de dentina radicular humana (4,25mm X 4,25mm e 3,00mm de espessura) foram divididos aleatoriamente em 8 grupos: (G1=nenhum tratamento, G2=aplicação de flúor gel, G3=irradiação com o laser Er:YAG, G4=aplicação de flúor gel + irradiação com o laser Er:YAG, G5=irradiação com o laser Nd:Y...

  18. Ana Carolina Escosteguy: Cenários dos estudos culturais

    Thaisa Cristina Bueno


    Full Text Available Autora do livro “Cartografia dos Estudos Culturais”, “Comunicação e recepção” (em coautoria com Nilda Jacks, “Leituras em comunicação, cultura e tecnologia”, além de coautora e organizadora em outras obras de referência sobre o tema cultura e comunicação no Brasil, Ana Carolina Escosteguy é hoje um dos nomes mais importantes quando se pensa em Estudos Culturais no país. Doutora em Ciências da Comunicação pela Universidade de São Paulo (2000, com pós-doutorado no CAMRI (Communication and Media Research Institute, associado ao Department of Journalism and Mass Communication da School of Media, Art and Design da University of Westminster (UK, Ana Carolina Escosteguy é professora titular da Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS e bolsista produtividade em pesquisa do CNPq, desde março 2001. Nesta entrevista ela discute pontos sensíveis da área, entre eles o pouco destaque das pesquisas desse campo têm tido no Jornalismo, o fato de a base teórica ser bem mais ampla que os tradicionais estudos de recepção a que são comumente aproximados, não se nega a tratar das confusões com a folkcomunicação, bem como as próprios limites e intersecções desse campo de estudos. Durante esta conversa, aproveita para apontar as obras que considera essenciais para adentrar na área e mostra coragem e segurança para se colocar como uma pesquisadora que busca entender o tempo atual, as tecnologias e as rupturas a partir da perspectiva do usuário. Confiram:

  19. Laser Development for Laser Fusion Applications


    SLL 80 676 copy 1 SAN D78-2306 Unlimited Release UC-21 aM* m ml 8 H Laser Development for Laser Fusion Applications Research Progress...Printed Copy $6.00; Microfiche $3.00 Accession Number: 3885 Publication Date: Dec 01,1978 Title: Laser Development for Laser Fusion Applications...Document: Archive, RRI, DEW Descriptors, Keywords: Laser Development Fusion Application Oscillator Amplifier Geometry Electron Beam Iodine Hydrogen


    Christine da Silva Schröeder


    Full Text Available Nossa proposta é incentivar a apropriação de abordagens paradigmáticas alternativas para a pesquisa na área de Administração da Informação (ADI, a partir de perspectivas que se contrapõem à ontologia positivista-funcionalista – ou, de outro lado, podem complementá-la, oportunizando a realização de estudos reflexivos, não necessariamente performativos, e “desnaturalizados”. Adotamos os conceitos de reflexividade, não-performatividade e desnaturalização a partir de seu uso por Fournier e Grey (2007, ao referirem-se aos estudos críticos em Administração (ou Critical Management Studies - CMS. Atestamos que os três conceitos nos são valiosos porque nos auxiliam a definir condições pelas quais entendemos que se manifesta pensamento crítico – e, por assim dizer, inspiram a pesquisa multi e interparadigmática. Através das possibilidades deste tipo de pesquisa, podemos lançar olhares potencialmente ampliados sobre a teoria e a prática em Administração da Informação, que trazem implicações não apenas epistemológicas, mas, sobretudo, metodológicas para os estudos da área.

  1. Marketing do mercado de luxo: Estudo de caso Victoria's Secret

    Ana Francisca Giuliani


    Full Text Available Este artigo teve por objetivo identificar quais são as estratégias de marketing utilizadas pela empresa varejista Victoria’s Secret para a fidelização do consumidor de luxo em nível global. O estudo caracterizou-se como uma pesquisa qualitativa, utilizando-se como estratégia de campo o estudo de caso de caráter ilustrativo. Para o alcance do objetivo proposto, dividiu-se o estudo em duas fases. Na primeira, denominada exploratória, buscou-se em dados secundários o embasamento para a construção do referencial teórico. Na segunda, adotou-se a técnica de pesquisa por observação, utilizando-se os sites da Victoria’s Secret, e analisou-se o composto de marketing aplicado ao mercado de luxo com base no modelo proposto por Nahás (2009. Concluiu-se que as estratégias da referida empresa se baseiam no luxo acessível, de modo que, além de conquistar o consumidor, a Victoria’s Secret consegue manter sua fidelidade por apresentar estratégias de forte apelo emocional.

  2. A sociologia funcionalista nos estudos organizacionais: foco em Durkheim

    Augusto Cabral

    Full Text Available O tema que estrutura este ensaio é o da sociologia funcionalista, particularmente em termos de sua influência nos estudos organizacionais. O seu foco de análise é duplo. Em um primeiro momento, as obras de Durkheim. Em um segundo momento, o impacto e a supremacia dos enfoques funcionalistas nos estudos organizacionais. Embora seus segmentos estejam inter-relacionados, ele é composto de quatro partes. Na primeira, é feita uma análise histórica da emergência e sistematização das ciências sociais, de modo a traçar sua evolução até o surgimento dos trabalhos de Durkheim. Na segunda, tomando como referencial a obra de Burrell e Morgan (1979, é estudado o paradigma funcionalista em termos de sua origem e expoentes, com destaque para Comte e Spencer, visando chegar a uma compreensão inicial do pensamento de Durkheim e de sua sociologia. Na terceira, a vida e as principais obras de Durkheim são sumariadas e discutidas. Por fim, o status atual dos estudos organizacionais -vistos como um conjunto impreciso, elástico e eclético de teorias e pesquisas sociais voltados para os problemas das organizações -é analisado em termos de seus pressupostos epistemológicos e ontológicos subjacentes, como meio de explicitar a supremacia dos enfoques positivistas-funcionalistas.

  3. O caso do psicodiagnóstico: um estudo institucional

    Marlene Guirado


    Full Text Available O psicodiagnóstico é uma prática recorrente de estudo de caso em Psicologia, independentemente de ser feito em consultórios particulares, escolas, hospitais, ambulatórios e/ou instituições para-educativas. O presente artigo discute a dimensão institucional desse atendimento na medida em que se trata de um dispositivo que, cada vez mais, legitima seu objeto: o conhecimento do psiquismo de quem se expõe aos serviços do psicólogo. Tal discussão parte do destaque de conceitos como discurso, sujeito, instituição e análise, tomados nos terrenos da Psicanálise e da análise de instituições concretas, para configurar uma possibilidade de estudo de caso que considere o contexto institucional do (ou, em que se fez o diagnóstico. Por fim, faz-se uma proposta de como proceder a um estudo de caso que suponha a força constitutiva desse contexto sobre o resultado do psicodiagnóstico de um cliente/paciente do psicólogo.

  4. Recrutamento de participantes no Estudo Longitudinal de Saude do Adulto

    Estela M L Aquino


    Full Text Available OBJETIVO: Apresentar as estratégias de comunicação e recrutamento no Estudo Longitudinal de Saúde do Adulto (ELSA-Brasil e discutir os resultados alcançados na constituição da coorte. MÉTODOS: As estratégias foram voltadas à divulgação, à institucionalização e ao recrutamento propriamente dito. As ações de comunicação pretenderam promover o fortalecimento de imagem institucional positiva para o estudo, a gestão de conhecimentos e o diálogo eficaz com seu público-alvo. Foi criado web site oficial visando dialogar com diferentes públicos, funcionar como difusor científico e contribuir para a consolidação da imagem do estudo perante a sociedade. RESULTADOS: Foram recrutados 16.435 mulheres e homens, servidores ativos e aposentados de seis instituições públicas de ensino e pesquisa para constituir a coorte de 15.105 participantes. As metas de recrutamento foram plenamente alcançadas nos seis centros, com leve predomínio de mulheres e daqueles mais jovens, e um pouco menos de servidores com menor escolarização. CONCLUSÕES: As estratégias utilizadas se mostraram adequadas e essenciais para o sucesso da captação e participação dos servidores.


    André Francisco Alcântara Fagundes


    Full Text Available Este trabalho objetivou o estudo da gestão da Cooperativa de Economia e Crédito Mútuo dos Profissionais da Saúde de Viçosa e Região (Unicred Viçosa, como forma de gerar uma melhoria nos negócios e assim ampliar o quadro social da cooperativa. Utilizou-se como metodologia a pesquisa descritiva e qualitativa por meio de estudo de caso. Os métodos de pesquisa utilizados foram a abordagem participativa e o questionário dirigido aos 430 cooperados da Unicred Viçosa – tamanho de amostra finita. O referencial teórico abordou bibliografia de marketing e estratégia, destacando a análise da matriz SWOT, a qual foi eleita como a mais adequada ferramenta de gestão para o caso da cooperativa. Concluiu-se com o estudo que a cooperativa Unicred Viçosa teria que estabelecer critérios mais eficazes para a comunicação de seus objetivos e metas aos cooperados, e que a matriz SWOT se mostrou eficiente no que tange ao suporte à tomada de decisão.

  6. RILIS laser room


    Footage of the RILIS laser room at ISOLDE. The Resonance Ionization Laser Ion Source (RILIS) is a chemically selective ion source which relies on resonant excitation of atomic transitions using tunable laser radiation. This video shows you the laser table with the different lenses and optics as well as an overview of the RILIS laser setup. It also shows laser light with different colors and operation by the RILIS laser experts. The last part of the video shows you the laser path from the RILIS laser room into the ISOLDE GPS separator room where it enters the GPS separator magnet.

  7. RILIS laser room HD


    Footage of the RILIS laser room at ISOLDE. The Resonance Ionization Laser Ion Source (RILIS) is a chemically selective ion source which relies on resonant excitation of atomic transitions using tunable laser radiation. This video shows you the laser table with the different lenses and optics as well as an overview of the RILIS laser setup. It also shows laser light with different colors and operation by the RILIS laser experts. The last part of the video shows you the laser path from the RILIS laser room into the ISOLDE GPS separator room where it enters the GPS separator magnet.

  8. Laser Drilling Practical Applications

    Yilbas, Bekir Sami


    This book introduces laser drilling processes including modelling, quality assessment of drilled holes, and laser drilling applications. It provides insights into the laser drilling process and the relation among the drilling parameters pertinent to improved end product quality. This book is written for engineers and scientists working on laser machining, particularly laser drilling.

  9. Mirrorless lasers

    Hema Ramachandran


    Experimental realization of mirrorless lasers in the last decade have resulted in hectic activity in this field, due to their novelty, simplicity and ruggedness and their great potential for application. In this article, I will review the various developments in this field in roughly chronological order, and discuss some possible applications of this exciting phenomenon, also termed as ‘random lasing’.

  10. Nanowire Lasers

    Couteau C.; Larrue A.; Wilhelm C.; Soci C.


    We review principles and trends in the use of semiconductor nanowires as gain media for stimulated emission and lasing. Semiconductor nanowires have recently been widely studied for use in integrated optoelectronic devices, such as light-emitting diodes (LEDs), solar cells, and transistors. Intensive research has also been conducted in the use of nanowires for subwavelength laser systems that take advantage of their quasione- dimensional (1D) nature, fl...

  11. Laser Research Lab

    Federal Laboratory Consortium — The Laser Research lab is thecenter for the development of new laser sources, nonlinear optical materials, frequency conversion processes and laser-based sensors for...

  12. Lasers in medicine.

    Viherkoski, E


    Since its discovery, the laser has been intensively investigated and used in medicine, first in ophthalmology then in ear, nose and throat surgery, gynaecology, neurosurgery etc. Development spans from the ruby and argon lasers in outpatient eye surgery to the carbon dioxide and Nd:YAG lasers in the operating theatres and further on to the PDT-dye lasers, excimer and solid state angioplasty lasers or flash lamp pumped "gallstone cracker" lasers. The CO2-Nd: YAG laser combination will be described as the state-of-art surgical laser. This simultaneous, coaxial and coherent combination laser offers a new possibility to cut and coagulate effectively at the same time. Operating times are shortened and bleeding volumes minimised. The CO2-Nd: YAG laser represents a new type of interaction between laser and tissue, laser enhanced tissue absorption, which will be described.

  13. Laser therapy (image)

    A laser is used for many medical purposes. Because the laser beam is so small and precise, it enables ... without injuring surrounding tissue. Some uses of the laser are retinal surgery, excision of lesions, and cauterization ...

  14. Laser-Driven Fusion.

    Gibson, A. F.


    Discusses the present status and future prospects of laser-driven fusion. Current research (which is classified under three main headings: laser-matter interaction processes, compression, and laser development) is also presented. (HM)

  15. Gasdynamic lasers: an introduction

    Anderson, J.D. Jr.


    The following topics are covered: elementary physics, thermodynamics and vibrational kinetics of the CO/sub 2/--N/sub 2/--H/sub 2/O or He gasdynamic laser, calculation of gasdynamic laser performance, comparison between theory and experiment, inversions behind normal shock waves, CO/sub 2/--N/sub 2/ gasdynamic lasers: state-of-the-art, the carbon monoxide gasdynamic laser, downstream mixing gasdynamic lasers, optical cavity considerations for gasdynamic lasers, aerodynamic windows, and diffusers. (MHR)

  16. Laser accidents: Being Prepared

    Barat, K


    The goal of the Laser Safety Officer and any laser safety program is to prevent a laser accident from occurring, in particular an injury to a person's eyes. Most laser safety courses talk about laser accidents, causes, and types of injury. The purpose of this presentation is to present a plan for safety offices and users to follow in case of accident or injury from laser radiation.

  17. Semiconductor Laser Measurements Laboratory

    Federal Laboratory Consortium — The Semiconductor Laser Measurements Laboratory is equipped to investigate and characterize the lasing properties of semiconductor diode lasers. Lasing features such...

  18. Laser Protection TIL

    Federal Laboratory Consortium — The Laser Protection TIL conducts research and analysis of laser protection materials along with integration schemes. The lab's objectives are to limit energy coming...


    Fernanda Melo Carneiro


    Full Text Available As plantas medicinais são utilizadas pelo homem desde o início da história e atualmente empregadas como recursos na medicina alternativa por grande parte da população mundial. Esse uso deve-se à facilidade de acesso às plantas em relação aos medicamentos alopáticos. O objetivo deste trabalho foi, primariamente, desenvolver uma análise cienciométrica sobre as tendências dos estudos com plantas medicinais no Brasil, investigando se o número de trabalhos cresceu ao longo dos anos. Além disso, foi identificamos as principais plantas que são estudadas pelo seu principio medicinal no Brasil. Para a pesquisa foi empregada a base de dados Scielo, com artigos de 1995 a 2011, utilizando a palavra “Planta Medicinal” como palavra-chave. Foram avaliados 329 artigos, mas somente 265 foram compatíveis à pesquisa. Artigos que não foram desenvolvidos no Brasil; que não utilizaram o termo planta medicinal; ou não citaram plantas foram excluídos das análises. Em cada artigo selecionado foram coletadas as seguintes informações: título do artigo, quantidade de autores, instituições responsáveis pelo estudo, local das instituições, ano de publicação, tipo de estudo (ex.: farmacológico, agropecuário e ecológico e as plantas que foram estudadas. Por meio de análises desses dados foi possível verificar as tendências dos estudos com plantas medicinais no Brasil. Conforme esperado, a maior parte dos artigos avaliados estão voltados para a Farmacologia, com aplicação em diversas áreas da saúde e em segundo lugar a Agropecuária, devido ao interesse em desenvolver produtos a partir de plantas para o controle de pragas. Entretanto, verificou-se o emprego em outras áreas, como a Bioquímica, Botânica, Ecologia, Genética/Molecular e Educação que apesar de serem menos frequentes, são essenciais, pois os estudos com plantas medicinais requerem profissionais de múltiplas áreas. Além da investigação da medicina popular

  20. Laser biophotonics

    Bashkatov, A. N.; Genina, E. A.; Priezzhev, A. V.; Tuchin, V. V.


    This issue of Quantum Electronics presents the papers that reflect the state-of-the-art of laser technologies used in biomedical studies and medical practice. Among the new technologies, one can note the methods of correlation and Doppler spectroscopy, as well as THz spectroscopy, in which biologically significant molecules are characterised by specific resonances. The latter topic is considered in the paper by Nazarov et al., where the dielectric function of aqueous solutions of glucose and albumin is studied using pulsed THz spectroscopy.

  1. Contribuições da fenomenologia para os estudos organizacionais

    Diego Luiz Teixeira Boava

    Full Text Available Este artigo discute elementos que viabilizam outra possibilidade de compreensão dos fenômenos administrativos, através de uma descrição propedêutica da fenomenologia e do método fenomenológico. Objetiva-se, assim, apresentar as principais contribuições e possibilidades da fenomenologia para os estudos organizacionais. Aprofunda-se em considerações sobre a fenomenologia em geral e os diversos tipos de métodos fenomenológicos em particular, buscando esclarecer sobre a filosofia existente nesses temas, para auxiliar os pesquisadores em seu labor diário. Discorre-se também sobre a redução, que na verdade são duas: a eidética e a fenomenológica. Tais reduções são vitais para retirar o homem de sua atitude natural. Outro assunto aqui abordado é a transposição do método fenomenológico do campo filosófico para o campo da pesquisa empírica. Diante dessa contextualização, tem-se o último assunto a ser abordado, que vai diretamente ao encontro do objetivo desta pesquisa, discutindo-se a utilização da fenomenologia no contexto da administração. A título de ilustração, são apresentados diversos estudos que têm a fenomenologia como tema, bem como um método fenomenológico empírico específico da área de estudos organizacionais. Dessa maneira, a temática neste artigo é situada, sendo preciso agora avançar em direção a outras possibilidades.

  2. Redes e Responsabilidade Social Corporativa: Um Estudo de Caso

    Adriana Teixeira Bastos


    Full Text Available  O presente estudo visa a contribuir para a elucidação de questões relacionadas aos temas responsabilidade social corporativa (RSC e redes de cooperação entre empresas. Com este intento busca-se, através de um estudo de caso, compreender quais os impactos das redes sobre as estratégias de RSC. O estudo de caso em questão está baseado nas ações de Desenvolvimento Regional Sustentável (DRS de uma instituição financeira, que considera esta prática como uma forma dela e de parceiros realizarem suas ações de RSC. O artigo está estruturado considerando-se inicialmente a introdução, a discussão teórica sobre os dois temas que se pretende relacionar (redes e RSC e, após a elucidação sobre a metodologia do trabalho, é apresentada a metodologia do programa DRS da instituição financiadora (Banco Digama e a descrição da aplicação prática do programa para um grupo de parceiros da rede. Dando continuidade, são apresentadas as análises e discussões e, por último, as considerações finais. Entre os principais itens da conclusão, observa-se que os objetivos das organizações, relacionados às RSC, podem ser diferentes entre si, assim como os resultados obtidos, permitindo, inclusive, a coexistência na rede de atores que não alcançaram, na totalidade, seus principais objetivos, embora realizem atividades relacionadas à responsabilidade social. 

  3. Jovem aprisionado em regime semi-aberto: um estudo transdisciplinar

    Lazzaron, Leandra Regina


    A presente dissertação, vinculada à linha de pesquisa “Criminologia e Controle Social”, do Programa de Pós-Graduação em Ciências Criminais, da Faculdade de Direito da Pontifícia Universidade Católica do Rio Grande do Sul, identifica o perfil do jovem apenado, aprisionado em regime semi-aberto, no Instituto Penal de Viamão, com base na escala PCL-R. O estudo de campo foi realizado na instituição prisional e avaliou 40 jovens, com idade de 18 a 23 anos, que cumprem pena em regime semi-aberto. O...

  4. Craniostenose em gêmeos: estudo genético

    Walter Carlos Pereira


    Full Text Available É relatada a ocorrência de formas clínicas diversas de craniostenose em gêmeos de sexo diferente. A menina apresentava obliteração completa da sutura coronaria e dos dois terços anteriores da sutura sagital; no menino a sutura sagital era a única afetada. O estudo genético mostrou que a craniostenose independe de aberrações cromossômicas, indicando ser transmitida por gens recessivos raros de natureza autossômica.

  5. Estudo teórico de formas condensadas de polianilinas

    Liliana Yolanda Ancalla Dávila


    Neste trabalho estudamos o efeito de empacotamento, em diferentes formas condensadas, sobre as propriedades estruturais e eletrônicas de um polímero orgânico conjugado, a polianilina, através de simulações teóricas. A metodologia teórica empregada depende do número de átomos nos sistemas escolhidos, e das propriedades investigadas. Assim, para os filmes com milhares de átomos, utilizamos métodos clássicos para a obtenção das propriedades estruturais. Já para o estudo das propriedades eletrôni...

  6. A entrevista motivacional com alcoolistas: um estudo longitudinal

    Oliveira,Margareth da Silva; Andretta,Ilana; Rigoni, Maisa dos Santos; Szupszynski, Karen Priscila Del Rio


    Este foi um estudo de seguimento com pacientes alcoolistas que participaram de um ensaio clínico em que foi empregada Entrevista Motivacional. A amostra constituiu-se de 152 sujeitos alocados randomicamente em dois grupos: grupo de intervenção submetido à Entrevista Motivacional (GI), e um grupo controle submetido a tratamento padrão (GC). Os instrumentos utilizados foram: entrevista estruturada e o FORM-90. Na avaliação inicial (T1), realizada entre os anos de 1999 e 2001, foram avaliados 15...

  7. Encefalopatia hepática: estudo de 50 casos

    Luiz Antonio de Lima Resende


    Full Text Available Os autores apresentam estudo retrospectivo de 50 pacientes com encefalopatia hepática atendidos no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto a partir de 1959 e discutem os aspectos clínicos, laboratoriais e anátomo-patológicos. Expõem os diagnósticos das hepatopatias, os fatores precipitantes dos episódios de coma e pré-coma hepático e enfatizam o papel da gasometria arterial no estabelecimento do diagnóstico.

  8. Anorexia nervosa e família : estudo de caso

    Simone Marques Borges


    Os transtornos alimentares têm despertado interesse entre os profissionais de saúde em decorrência do crescente aumento de casos, alguns deles veiculados na mídia. Apesar disso, muitas dúvidas ainda cercam essas patologias. O funcionamento do sistema familiar de adolescentes com diagnóstico de anorexia nervosa tem sido tema de investigação por autores da terapia familiar sistêmica e os estudos têm relacionado o transtorno a algumas características da dinâmica conjugal e familiar. Esta pesquis...

  9. O efeito do stresse no julgamento moral: um estudo experimental

    Carvalhinho, Helena Paula Polido


    Dissertação de Mestrado, Psicologia Clínica e da Saúde, Faculdade de Ciências Humanas e Sociais, Universidade do Algarve, 2015 Alguns estudos recentes sugerem que as emoções têm um impacto significativo no julgamento moral e, em certa medida, a variação de estados emocionais induzida por situações de stresse também parece condicionar a resposta moral. Neste sentido, alguns autores sugerem que sujeitos sob impacto de stresse realizam julgamentos morais menos calculistas, mais emocionais. Co...

  10. "Buzz marketing" : estudo de caso da marca Red Bull

    Conceição, Miguel David


    Este relatório é baseado no estágio efetuado na agência de publicidade Ogilvy & Mather e é dedicado à temática do Buzz Marketing. De modo a poder explorar a fundo as dinâmicas deste tema foi feita uma análise à estratégia de marketing da marca Red Bull, considerada como um dos principais estudos de caso no âmbito do Buzz Marketing. Este tema pode ser definido como uma estratégia de marketing inovadora cujo objetivo principal é a criação de conversas entre os consumidores, colocando-os a falar...

  11. Miopatia miotubular: estudo clinico, eletrofisiologico e histologico de um caso

    José L. Alonso


    Full Text Available São apresentados os resultados dos exames clínicos, eletrofisiológicos e do estudo do ponto motor, da imunofluorescência, da histoquímica e da ultrami-croscopia da biópsia muscular de um caso de miopatia miotubular. São discutidos estes resultados em relação aos achados de 56 casos desta moléstia consignados na literatura até 1978, sendo dada enfase à etiopatogenia.

  12. O ensino de auditoria em Angola estudo de caso

    Capita, Francisco Ernesto


    Trabalho de Projecto apresentado ao Instituto de Contabilidade e Administração do Porto para a obtenção do grau de Mestre em Auditoria, sob orientação da Professora Doutora Alcina Augusta de Sena Portugal Dias Esta pesquisa tem como objectivo contribuir para a melhoria da formação dos potenciais auditores formados a partir das Instituições de Ensino Superior (IES) em Angola, tendo em conta as expectativas actuais bem como os desafios do mercado. Trata-se de um estudo de caso considerado so...

  13. Sintese, estudos estruturais e reatividade de naftoquinoniminas estaveis

    Luiz Antonio Mazzini Fontoura


    Novas naftoquinoniminas estáveis foram sintetizadas por amonólise de naftoquinonas 2,5,8-trissubstituí das. Derivados dos novos compostos foram obtidos por reações de metilação. acetilação. condensação com cetonas e cicloadição com ciclopentadieno. Um estudo de tautomeria quinonimina-quinona através da técnica de UV-visível foi também realizado. New stable naphthoquinonimines were synthesised by ammonolysis of 2.5.8-trisubstituted naphthoquinones. Derivatives of the new compounds were obta...

  14. Marketing educacional: um estudo comparativo das atividades de marketing

    Marta Maria Cunha Carneiro


    A revisão teórica apontou uma visão geral dos temas de marketing e educação por meio da cronologia histórica, da discussão conceitual, da relevância teórica e prática de cada assunto, dos principais desafios para pesquisa e o desenvolvimento do tema marketing educacional. Identificou-se e discutiu-se as atividades de marketing desenvolvidas nas instituições de ensino superior à luz dos fundamentos teóricos. A metodologia abordou os aspectos relacionados ao protocolo do estudo de caso e uma pe...

  15. Trajetória dos estudos de velhice no Brasil

    Barros,Myriam Moraes Lins de


    Este artigo pretende traçar a trajetória das pesquisas antropológicas sobre velhice realizadas no Brasil desde a década de 1970, e apresentar as discussões atuais e seus desdobramentos em projetos de investigação. Dentro do campo de estudos sobre velhice foram escolhidas algumas temáticas: identidade social, memória, trajetória de vida, sociabilidade, espaço urbano, trabalho e aposentadoria, gênero, família e corpo. O recorte histórico procurou apontar as questões teóricas que foram sendo inc...

  16. Estudos sobre a estabilidade do desenho da figura humana (DHF)



    Com o intuito de pesquisar a estabilidade do desenho da figura humana (DHF) e a pertinência das modificações feitas pela autora deste trabalho, comparam-se as normas de revalidação para crianças de 5 e 6 anos elaboradas por Koppitz (1968), e as desenvolvidas em Ottawa por Groves e Fried (1991) com as elaboradas por Taborda-Barbenza em San Luis, Mendoza e San Juan (Argentina, 1993). Este estudo comparativo realizou-se também em 127 crianças de 4 anos de San Luis e Villa Mercedes, considerando ...

  17. Dançaterapia no autismo: um estudo de caso



    O autismo é uma das desordens neurológicas mais comuns que afetam o desenvolvimento neuropsicomotor de crianças. Intervenções terapêuticas podem intervir nos transtornos de comunicação e nos comportamentos estereotipados, desse modo a dança, como terapia, pode ativar vias sensoriais que viabilizam o aprimoramento do gesto. Este estudo visou observar os efeitos da dançaterapia no desempenho motor e gestual, no equilíbrio corporal e na marcha, bem como na qualidade de vida de um adolescente com...

  18. O colecionador de vinil : um estudo vídeo-etnográfico

    João Pedro dos Santos Fleck


    O presente estudo tem por objetivo fornecer uma maior compreensão acerca do que motiva o comportamento de compra de coleção, utilizando como objeto de estudo, os colecionadores de discos de vinil da cidade de Porto Alegre. A questão central de pesquisa pode ser definida como: quais as causas motivadoras do consumo de discos vinil? A importância do estudo se justifica devido ao fato da existência de lacunas nos estudos sobre comportamento de consumo de coleção e sobre a tendência nostálgica in...

  19. Estudo sobre a prevalência do tabagismo entre adolescentes no Brasil

    Dantas, Deborah Rose Galvão


    p. 1-121 Objetivo:Observar a prevalência do tabagismo entre adolescentes no Brasil;analisar fatores de risco ao tabagismo.Métodos:Estudo descritivo observacional e estudo de corte transversal. Foram pesquisados estudos de corte transversal ou coorte nos últimos 40anos,contendo percentuais de prevalência e/ou experimentação nos bancos de dados:MEDLINE, SciELO, LILACS e PubMeD; por busca ativa e comunicados oficiais,sendo selecionados 84 trabalhos.Foi realizado estudo de corte transversal de...

  20. Sintomas depressivos em crianças: estudos com duas versões do CDI

    Miriam Cruvinel

    Full Text Available O objetivo deste estudo foi identificar o número de crianças com sintomas depressivos em duas amostras de estudantes da cidade de campinas. Utilizou-se, no estudo 1, a versão brasileira do Inventário de Depressão Infantil (CDI e, no estudo 2, a versão original. Do estudo 1, realizado em 2001, participaram 169 estudantes de 3ª, 4ª e 5ª séries, e, do estudo 2, conduzido em 2005, 157 alunos de 3ª e 4ª séries. A prevalência de sintomatologia depressiva no estudo 1 foi de 3,55%, e, no estudo 2, de 17%. Em ambos os estudos, não foram encontradas diferenças significativas entre a média no CDI em relação às variáveis demográficas. conclui-se pela necessidade de mais estudos nacionais de prevalência no ensino fundamental e de esforços direcionados não só para a identificação dos fatores de risco, de proteção e das variáveis associadas mas também do refinamento dos instrumentos de medidas da depressão infantil.

  1. Effect of different kinds of lasers on micro-tensile bond strength of non-carious sclerotic dentin%2种激光对硬化牙本质粘接强度影响的实验研究

    孙海燕; 仇丽鸿


    Objective To compare the effect of different kinds of lasers on micro-tensile bond strength of non-carious sclerotic den-tin.Methods Thirty human molars with occlusal wear were randomly divided into group E ,group N and the control group .Group E were treated with Er,Cr:YSGG laser,while group N were treated with Nd:YAG laser.Then all three groups were treated with Adper Prompt L-Pop,filled with Z350 resin,and preserved in normal saline (37 ℃)for 24 h.Then fatigue test pieces were made and the mi-cro-tensile bond strength was evaluated .Results were subject to statistical analysis using one-way analysis of variance (ANOVA).Re-sults The bonding strength was (24.71 ±3.13)MPa in group E,(21.72 ±2.36)MPa in group N,and (18.61 ±2.01)MPa in the control group.The differences among all groups were statistically significant (P<0.05).The breakage mostly happened in adhesive dentine surface .Conclusions The bonding strength of molars to Z 350 resin can be increased by Er ,Cr:YSGG laser and Nd:YAG la-ser,and the former is more effective .%目的:比较2种不同激光对硬化牙本质与复合树脂粘接强度的影响。方法选择牙本质视觉分级3级以上牙面磨损的后牙30颗,按照随机数字表法随机分为Er,Cr:YSGG激光处理组( E组)、Nd:YAG激光处理组( N组)和对照组,联合Adper Prompt L-Pop处理、Z350复合树脂充填,置于37℃生理盐水中24 h,制作微拉伸试件并进行微拉伸粘接强度测试。采用SPSS13.0软件对微拉伸粘接强度值进行单因素方差分析。结果 E组粘接强度(24.71±3.13)MPa,N组粘接强度(21.72±2.36)MPa,对照组粘接强度(18.61±2.01)MPa。 E组的粘接强度最高,3组之间相比较差异均有统计学意义(P<0.05)。体视显微镜观察结果发现断裂多发生于牙本质-树脂粘接界面。结论 Er,Cr:YSGG激光和Nd:YAG激光均能够提高硬化牙本质与复合树脂的粘接强度,且Er

  2. Perspectivas psicossociais para o estudo do cotidiano de trabalho

    Fábio de Oliveira


    Full Text Available Este estudo teve por objetivo analisar o debate e o aprofundamento teórico e metodológico desenvolvido nos estudos sobre a vida cotidiana no trabalho. A investigação partiu do diálogo interdisciplinar entre a antropologia do trabalho, a ergologia e a psicologia social do trabalho e sistematizou as contribuições mútuas entre esses campos científicos, suas aproximações e seus afastamentos da tematização e da apropriação da atividade humana no trabalho sob a perspectiva do cotidiano. A análise comparativa destacou eixos que diferenciam as formas de aproximação ao objeto, que se referem às relações estabelecidas entre saberes práticos e técnico-científicos e aos modos de intervenção sobre as situações de trabalho. As abordagens comparativas compartilham o interesse em conhecer o trabalho real, o valor conferido aos conhecimentos dos trabalhadores e a sensibilidade às dimensões micropolíticas do cotidiano. Conclui-se que a localização em cada um desses eixos depende da maior ou menor filiação às tradições da antropologia ou da ergonomia.

  3. Revendo estudos sobre a assistência domiciliar ao idoso

    Andreza Aparecida de Lima


    Full Text Available A assistência domiciliar apresenta-se como uma recente modalidade de cuidado aos idosos, sobretudo no Brasil, e vem sendo inserida nas políticas públicas. Este estudo busca identificar produções científicas acerca da assistência domiciliar, a fim de verificar quais as contribuições desta na dinâmica social do idoso. A pesquisa foi realizada nas bases de dados LILACS e MEDLINE, com artigos publicados entre os anos de 2001 a 2011, nos idiomas português e inglês. A combinação de palavras-chave utilizada foi home care e elderly, elderly e care, e elderly e caregiver, e as correspondentes em português. A discussão dos resultados evidenciou a importância da assistência domiciliar, principalmente para idosos solitários ou negligenciados. A revisão revelou poucos estudos referentes à assistência domiciliar na dinâmica social de idosos e a necessidade de ampliar as discussões para além do campo da saúde.

  4. Para um estudo psicológico das virtudes morais

    La Taille Yves de


    Full Text Available O propósito deste artigo é defender a importância de estudos psicológicos das virtudes morais (como generosidade, coragem, humildade, fidelidade etc.. Tal defesa é realizada de várias formas. Do ponto de vista filosófico, o tema das virtudes não somente é clássico (Ver Aristóteles, por exemplo como tem sido rediscutido por autores contemporâneos descontentes com as limitações da ética moderna, em geral baseada no conceito de direito. Do ponto de vista psicológico, o autor defende a idéia segundo a qual as virtudes morais não somente participam da gênese da moralidade, como representam traços de caráter essenciais à coesão da personalidade moral. Tal perspectiva está, de certa forma, anunciada na obra de Piaget sobre o juízo moral, como em autores outros como Tugendhat. Ela está também presente nos estudos sobre a relação entre o sentimento de vergonha e a ética. Finalmente, aponta-se que, no que se refere à educação moral, as virtudes podem representar um tema rico e sugestivo para a reflexão das crianças e adolescentes.

  5. Marketing, Propaganda e Publicidade - um estudo dos termos no Brasil

    Miguel Arantes Normanha Filho


    Full Text Available Este estudo contribui para a verificação empírica das diversas interpretações e aplicabilidades dadas aos pares de termos marketing e propaganda, propaganda e publicidade, em especial pela forma e uso como se fossem sinônimos, num contexto de negócios que pode acarretar prejuízos às empresas. O estudo parte da observação de que utilizar marketing e propaganda como sinônimos não é uma questão semântica, mas conceitual, em que a aplicação de uma ferramenta [propaganda] específica, em detrimento de uma filosofia do negócio [marketing], leva empresários [decisores] a equívocos estratégicos, que influenciam e comprometem o capital de giro e, conseqüentemente, a saúde econômico-financeira da empresa.

  6. Perspectivas de estudos comparados a partir da aplicação da escala Likert de 4 pontos: um estudo metodológico da pesquisa TALIS

    Rose Meri Trojan; Robson Sipraki


    Este estudo analisa a utilização da Escala Likert na pesquisa Teaching and Learning International Survey (TALIS). O tema justifica-se pelo uso recorrente da estatística nas pesquisas educacionais, especialmente, aquelas que permitem estudos comparados internacionais. O objetivo é avaliar análises apresentadas no relatório TALIS (OCDE, 2009) e verificar as perspectivas do uso da Escala Likert em estudos que utilizam os resultados desta pesquisa. Metodologicamente, partiu-se dos fundamentos est...

  7. Visible Solid State Lasers

    Hikmet, R.A.M.


    Diode lasers can be found in various applications most notably in optical communication and optical storage. Visible lasers were until recently were all based on IR diode lasers. Using GaN, directly blue and violet emitting lasers have also been introduced to the market mainly in the area of optical

  8. Applications of Semiconductor Lasers

    LI Te; SUN Yan-fang; NING Yong-qiang; WANG Li-jun


    An overview of the applications of semiconductor lasers is presented. Diode lasers are widely used today,and the most prevalent use of the laser is probably in CD and DVD drives for computers and audio/video media systems. Semiconductor lasers are also used in many other fields ranging from optical fiber communications to display,medicine and pumping sources.

  9. Visible Solid State Lasers

    Hikmet, R.A.M.


    Diode lasers can be found in various applications most notably in optical communication and optical storage. Visible lasers were until recently were all based on IR diode lasers. Using GaN, directly blue and violet emitting lasers have also been introduced to the market mainly in the area of optical

  10. Diode Pumped Fiber Laser.


    FIBER LASERS I. Nd:YAG FIBER LASER FABRICATION .............. 5 A. FIBER GROWTH .......................... 5 B. FIBER PROCESSING 7...1.32 pm FIBER LASERS I. Nd:YAG FIBER LASER FABRICATION A. FIBER GROWTH The single crystal fibers used in this work were grown at Stanford University

  11. Obstacles to Laser Safety

    Barat, K


    The growth of laser development & technology has been remarkable. Unfortunately, a number of traps or obstacles to laser safety have also developed with that growth. The goal of this article is to highlight those traps, in the hope that an aware laser user will avoid them. These traps have been the cause or contributing factor of many a preventable laser accident.

  12. Lasers in cosmetic dentistry.

    Pang, Peter


    Lasers have become a necessary instrument in the esthetic restorative armamentarium. This article presents smile design guidelines for soft tissue lasers, as well as an overview of hard tissue procedures that may be performed using all-tissue lasers. The goal is to help dentists determine the appropriate laser for a given clinical situations.

  13. New laser materials for laser diode pumping

    Jenssen, H. P.


    The potential advantages of laser diode pumped solid state lasers are many with high overall efficiency being the most important. In order to realize these advantages, the solid state laser material needs to be optimized for diode laser pumping and for the particular application. In the case of the Nd laser, materials with a longer upper level radiative lifetime are desirable. This is because the laser diode is fundamentally a cw source, and to obtain high energy storage, a long integration time is necessary. Fluoride crystals are investigated as host materials for the Nd laser and also for IR laser transitions in other rare earths, such as the 2 micron Ho laser and the 3 micron Er laser. The approach is to investigate both known crystals, such as BaY2F8, as well as new crystals such as NaYF8. Emphasis is on the growth and spectroscopy of BaY2F8. These two efforts are parallel efforts. The growth effort is aimed at establishing conditions for obtaining large, high quality boules for laser samples. This requires numerous experimental growth runs; however, from these runs, samples suitable for spectroscopy become available.

  14. Multibeam fiber laser cutting

    Olsen, Flemming Ove; Hansen, Klaus Schütt; Nielsen, Jakob Skov


    The appearance of the high power high brilliance fiber laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating Cutting laser, the CO2 laser. However, quality problems in fiber-laser...... cutting have until now limited its application to metal cutting. In this paper the first results of proof-of-principle Studies applying a new approach (patent pending) for laser cutting with high brightness and short wavelength lasers will be presented. In the approach, multibeam patterns are applied...... to control the melt flow out of the cut kerf resulting in improved cut quality in metal cutting. The beam patterns in this study are created by splitting up beams from two single mode fiber lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W...

  15. Multibeam Fibre Laser Cutting

    Olsen, Flemming Ove

    The appearance of the high power high brilliance fibre laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating cutting laser, the CO2-laser. However, quality problems in fibre-laser...... cutting have until now limited its application in metal cutting. In this paper the first results of proof-of-principle studies applying a new approach (patent pending) for laser cutting with high brightness short wavelength lasers will be presented. In the approach, multi beam patterns are applied...... to control the melt flow out of the cut kerf resulting in improved cut quality in metal cutting. The beam patterns in this study are created by splitting up beams from 2 single mode fibre lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W of single...

  16. A interface estudos discursivos e estudos ergológicos =The interface between discursive studies and ergologic studies

    Silva, Maria Cecília Pérez de Souza e


    Full Text Available Este artigo tem por objetivo explicitar caminhos teórico-metodológicos aos quais temos recorrido a fim de consolidar o estudo das relações linguagem/trabalho, mais especificamente dos estudos discursivos e ergológicos. Adotar a perspectiva discursiva implica considerar a língua não como instrumento informacional, transparente, mas como polissêmica e opaca. Implica também aceitar que a discursividade define uma ordem própria diversa da materialidade da linguagem, mas que se realiza na língua. Compartilhar a abordagem ergológica significa pensar a atividade de trabalho como o encontro entre as normas e os seres humanos capazes, por suas escolhas, de traduzi-las em cada situação. Ambas as abordagens encontram abrigo no paradigma indiciário, que supõe a existência de um rigor flexível e elástico. Flexível porque não exige o estabelecimento de uma verdade única, universal e inquestionável; elástico porque não prescinde do rigor, não abre mão da interpretação.

  17. Medidas de rede e apoio social no Estudo Pró-Saúde: pré-testes e estudo piloto

    Dóra Chor

    Full Text Available Neste artigo, relatamos a metodologia de seleção de perguntas sobre rede e apoio social, incluídas em um estudo de coorte de 4.030 funcionários de uma universidade pública no Rio de Janeiro. Em primeiro lugar, a adequação de conceitos foi explorada em discussões de grupos de voluntários. Em seguida, o questionário do Medical Outcomes Study foi submetido a procedimentos padronizados de tradução e versão. As perguntas foram a seguir avaliadas em cinco etapas de pré-testes e estudo piloto. Nenhuma pergunta apresentou proporção de não-resposta acima de 5%. Os coeficientes de correlação de Pearson entre os itens foram distantes de zero e da unidade; a correlação entre cada item e o escore de sua dimensão foi superior a 0,80 em quase todos os casos. Finalmente, os coeficientes Alpha de Cronbach foram superiores a 0,70 em todas as dimensões. Os resultados sugerem que aspectos de rede e apoio social serão mensurados adequadamente, permitindo a investigação de suas associações com desenlaces relacionados à saúde em um grupo populacional no Brasil.

  18. High power fiber lasers

    LOU Qi-hong; ZHOU Jun


    In this review article, the development of the double cladding optical fiber for high power fiber lasers is reviewed. The main technology for high power fiber lasers, including laser diode beam shaping, fiber laser pumping techniques, and amplification systems, are discussed in de-tail. 1050 W CW output and 133 W pulsed output are ob-tained in Shanghai Institute of Optics and Fine Mechanics, China. Finally, the applications of fiber lasers in industry are also reviewed.

  19. Laser Hardening of Metals

    Institute for Laser Physics; V.A.Serebryakov; K.V.Gratzianov; A.S.Eremenko; A.A.Timopheev; SPBSUITMO; M.V.Volkov


    Results of experiments on laser hardening of various materials with intensity 109~1010W/cm2 are represented. Nd:glass laser with energy up to 45J with a pulse duration ~30ns was used as a source of ra diation. Comparative researches of the laser peening for the various target areas are fulfilled. Results of laser hardening were determined by the microstructure analysis. The new approach to creation of the industrial laser for peening is discussed.

  20. The laser in urology

    Hofstetter, Alfons G.


    Laser is an acronym for a physical principle and means: Light Amplification by stimulated Emission of Radiation. This principle offers a lot of tissue/light effects caused by the parameters: power density/time and the special qualities of the laser light. Nowadays for diagnosis and therapy following lasers are used in urology: Krypton- and Dye-lasers as well as the Neodymium-YAG- (nd:YAG-), Holmium-YAG (Ho:YAG-), Diode-, Argon- and the CO2-lasers.

  1. Laser ablation principles and applications


    Laser Ablation provides a broad picture of the current understanding of laser ablation and its many applications, from the views of key contributors to the field. Discussed are in detail the electronic processes in laser ablation of semiconductors and insulators, the post-ionization of laser-desorbed biomolecules, Fourier-transform mass spectroscopy, the interaction of laser radiation with organic polymers, laser ablation and optical surface damage, laser desorption/ablation with laser detection, and laser ablation of superconducting thin films.

  2. Otomycosis: a retrospective study Otomicoses: um estudo retrospectivo

    Zélia Braz Vieira da Silva Pontes


    Full Text Available Otomycosis is a fungal infection of the external ear canal with only a few studies about its real frequence in Brazil. AIM: to evaluate otomycosis frequence and characteristics in patients with clinical suspicion of external otitis. STUDY DESIGN: Retrospective study with transversal cohort (2000-2006. MATERIALS AND METHODS:103 patients were assigned to mycological diagnosis (direct microscopic examination and culture. RESULTS: Otomycosis was diagnosed in 19.4% of the patients. Patient age varied from 2 to 66 years (an average of 23.5 years of age, and 60% of otomycosis cases were seen in women between 2 to 20 years of age. Chronic otitis, previous antibiotic therapy and the lack of cerumen were predisposing factors; itching, otalgia, otorrhea and hypoacusis were the symptoms reported by the patients. The most frequently isolated species were C. albicans (30%, C. parapsilosis (20%, A. niger (20%, A. flavus (10%, A. fumigatus (5%, C. tropicalis (5%, Trichosporon asahii (5% and Scedosporium apiospermum (5%. CONCLUSIONS: Otomycosis is endemic in João Pessoa-PB. Clinical exam and mycological studies are important for diagnostic purposes because otomycosis symptoms are not specific.Otomicose é uma infecção fúngica do conduto auditivo externo com poucos estudos sobre sua real frequência no Brasil. OBJETIVO: Avaliar a frequência e características das otomicoses em pacientes com suspeita clínica de otite externa. DESENHO DO ESTUDO: Estudo retrospectivo com corte transversal (2000-2006. MATERIAL E MÉTODOS: 103 pacientes foram atendidos para diagnóstico micológico (exame microscópico direto e cultivo. RESULTADOS: Otomicoses foram diagnosticadas em 19,4% dos pacientes. A idade desses pacientes variou de 2 a 66 anos (média de 23,5 anos e 60% das otomicoses foram observadas em mulheres entre 2 a 20 anos de idade. Otite crônica, antibioticoterapia prévia e ausência de cerume foram os fatores predisponentes e prurido otológico, otalgia

  3. Estudos de Comunidade e ciências sociais no Brasil

    Nemuel da Silva Oliveira


    Full Text Available O objetivo deste artigo é fazer um balanço da literatura sobre os Estudos de Comunidade (EC no Brasil, destacando o contexto intelectual em que foram produzidos e os debates que suscitaram, especialmente entre as décadas de 1940 e 1960. Método de pesquisa em comunidades, oriundo da Antropologia, em investigações sobre o processo de mudança social, os EC estiveram em voga nos Estados Unidos entre os anos 1920 e 1950, tendo papel fundamental na institucionalização das Ciências Sociais no Brasil. Destacamos três aspectos na produção desses estudos no país, iniciando com uma abordagem conceitual: definições, origem e sua relação com temáticas marcantes nos anos 1950. Em seguida, privilegiamos os aspectos relacionados ao papel dos EC na história das Ciências Sociais no Brasil, com destaque para o processo de institucionalização das Ciências Sociais. Por fim, revisitamos os debates que tais estudos geraram entre os cientistas sociais quanto ao padrão de trabalho sociológico a ser desenvolvido naquele momento.The purpose of this article is to examine the literature about Community Studies(CS in Brazil, highlighting their intellectual context of production and the debates evoked by them, especially between the 1940's and 1960's. As a research method arising from Anthropology on communities in social change process, CS was used in United States between 1920's and 1950's, and played a fundamental role in the institutionalization of Social Sciences in Brazil. Three aspects are highlighted on CS production: first, in a conceptual approach, we discuss their definitions, origins and relation to main topics in the 1950's. The second aspect is related to the role of CS in the history of Social Sciences, especially their institutionalization process. By the end, we revisit the debates between social scientists about the sociological work standard to be developed at that time.

  4. Imagem organizacional: um estudo de caso sobre a PUC Minas.

    Alexandre de Pádua Carrieri


    Full Text Available Esta pesquisa propôs conhecer a imagem corporativa, considerando sua importância para a administração das organizações no cenário atual de maior competitividade e de exigências por parte de segmentos do seu público. O estudo parte da formação da cultura e da identidade de uma organização, analisando estes itens como fundamentais na definição da imagem de uma instituição. Tomando a Pontifícia Universidade Católica de Minas Gerais - PUC Minas - enquanto objeto de estudo, utilizou-se como estratégia metodológica a pesquisa qualitativa, com a análise de conteúdo. O trabalho foi realizado em duas etapas: entrevistas com os gestores da Universidade e pesquisa de campo com segmentos de públicos de interesse tais como: professores e alunos de escolas de segundo grau, alunos de graduação e profissionais de recursos humanos. Observou-se que novas formas de relacionamento entre a organização e seus públicos de interesse foram criadas. Foram também implantados novos meios de comunicação – mais modernos, ágeis e editorialmente trabalhados – e estruturados novos processos de comunicação e interlocução, oportunizando melhor controle para a alta administração, da imagem da sua Universidade. Palavras-chave: Estudos organizacionais; imagem organizacional; universidade Abstract This research has purpose know a little more about corporative image, considering its importance to management of organizations in current context of higher competition and greater demand. This study came from the configuration of the culture and identity of organization, foreseeing those items as fundamentals to definition of any institution’s image. Taking the Pontifícia Universidade Católica de Minas Gerais - PUC Minas – as object of study, the content analysis was carried out through a qualitative research - the employed methodological strategy. The work was conducted in two stages: (I interviews with managers, and (II field research with

  5. Estudos sobre a toxicologia da ε-caprolactama

    Marcus Vinicius Justo Bomfim


    Full Text Available A ε-caprolactama (CAP é um monômero precursor de polímeros denominados nylon 6. Esses polímeros destinam-se à produção de tapetes, vestuário e materiais plásticos tais como equipamentos, sistemas e componentes automotivos, conectores, além de embalagens plásticas. Resíduos de CAP podem migrar de embalagens plásticas de nylon 6 para os alimentos. Diante disso, foi de interesse realizar uma revisão dos efeitos relativos à exposição à CAP e o seu impacto sobre a saúde humana. Estudos epidemiológicos indicam a possibilidade da CAP causar inflamações oculares e cutâneas, além de irritações no sistema respiratório. Pode ocorrer ainda hipotensão, taquicardia, palpitações, rinorréia, ressecamento nasal, efeitos geniturinários e sobre a reprodução como distúrbios nas funções menstrual e ovariana, e complicações no parto; além de problemas neurológicos e hematológicos. Estudos com animais são consistentes com tais relatos. Os estudos de genotoxicidade in vitro e in vivo por via oral e intraperitoneal mostram em sua grande maioria, resultados negativos, bem como ausência de efeitos carcinogênicos em ratos e camundongos e sobre o desenvolvimento e reprodução em ratos e coelhos.ε -Caprolactam (CAP is a precursor monomer of nylon 6 polymers. Nylon 6 is used in the manufacture of carpets, clothes and plastic materials, such as equipment, systems and automotive components, connectors and plastic packaging. CAP residues can migrate from nylon 6 plastic packaging to foods. Given this fact, this review was realized concerning the effects of CAP exposure and its impact on human health. Epidemiological studies indicate that CAP could cause ocular, cutaneous and respiratory irritations, as well as hypotension, tachycardia, palpitations, rhinorrhea, nose dryness, neurological and blood problems, and genitourinary and reproductive effects, such as alterations in ovarian-menstrual functions and pregnancy

  6. Tratamento cirúrgico da laringomalácia grave: estudo retrospectivo de 11 casos

    José Antonio Pinto


    Full Text Available A laringomalácia é a anomalia congênita da laringe mais frequente, sendo responsável por cerca de 60% a 75% dos casos de estridor congênito. Apesar de seu curso benigno e autolimitado, 10% dos casos necessitam de intervenção. Atualmente, as supraglotoplastias são consideradas o tratamento padrão da laringomalácia grave. OBJETIVO: Descrever a experiência adquirida pelos autores no tratamento cirúrgico dos pacientes com laringomalácia grave. Metodologia: Estudo retrospectivo. MÉTODO: Os prontuários de 11 casos consecutivos de laringomalácia grave, submetidos ao tratamento cirúrgico entre 2003 e 2012, foram analisados quanto à idade, gênero, sintomas, doenças associadas, técnica cirúrgica adotada, tempo de extubação, complicações cirúrgicas, tempo de internação e evolução clínica. RESULTADOS: Dos 11 casos de laringomalácia grave, seis pacientes (54,5% foram operados com o uso do laser de CO2 e em cinco pacientes (45,5% foram realizadas a técnica a frio. Apenas um paciente (9,1% necessitou reabordagem cirúrgica. Não foram observados casos de complicações cirúrgicas. Todos os pacientes apresentaram melhora clínica importante. CONCLUSÃO: A supraglotoplastia mostrou-se um procedimento eficaz e seguro no tratamento da laringomalácia grave.

  7. Interdisciplinaridade nos Estudos de Tradução

    José Lambert


    Full Text Available Desde 1992 (Snell-Hornby et al. 1994 os Estudos de Tradução* (doravante EdT reivindicaram o estatuto de  “interdisciplina”.  Aliás, ainda há dúvidas sobre seu estatuto acadêmico que é mais recente em relação à profissão. Desde Holmes 1988 [1972], o desenvolvimento dos EdT foi, várias vezes, considerado uma história de sucesso; embora não se saiba claramente se os resultados acadêmicos (argumentos e componentes peculiares vinculados ao seu prestígio, tais como livros, sociedades, estudiosos reconhecidos, congressos, foram mais decisivos do que o mercado da tradução no progressivo reconhecimento dos EdT.

  8. estudo numa população do Grande Porto

    Baptista, Diogo de Sousa


    Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas A Hipersensibilidade Dentinária é uma temática fundamental na saúde oral da atualidade. No presente estudo faz-se uma reflexão sobre a perceção da população adulta acerca da Hipersensibilidade Dentinária, condição geral de saúde da amostra, hábitos parafuncionais, parâmetros com variação, prevalência, hábitos de higiene oral ...

  9. Estudos Africanos em Portugal e Espanha: perspectivas comparadas

    Heimer, Franz-Wilhelm; Tomàs, Jordi


    Desde meados do século XX, a acompanhar o processo de descolonização e as trajectórias pós-coloniais em África, constituiu-se a nível internacional uma nova área do saber, a dos estudos africanos interdisciplinares em ciências sociais (no sentido amplo, incluindo a economia e a história). Retomando e transformando algumas vezes tradições anteriores, fundou-se mundo afora neste domínio uma larga centena de instituições científicas, de investigação e de ensino. Criaram-se, na Europa Ocidental e...

  10. Planeamento de uma estrada utilizando CCS Candy - Caso de estudo

    Oliveira, Sara Maria de


    O tema desta dissertação foi escolhido tendo em consideração a crescente necessidade de planeamento de empreitadas de construção de estradas, sendo um dos objetivos desta dissertação o de oferecer uma visão global do processo de planeamento da construção de uma estrada, focado apenas no fator tempo, recorrendo a ferramentas informáticas e utilizando um caso de estudo de uma estrada real e já construída. Inicialmente, faz-se uma breve descrição dos métodos de planeamento mais aplicados em p...

  11. Estudos sobre a paz e cultura da paz

    Pureza, José Manuel


    Segundo o autor, a cultura da paz implica uma mudança quer na forma como a “alta cultura” lida com a realidade quer no tipo de abordagem que o senso comum faz às relações sociais, sendo que a ruptura com a ideologia conservadora, ou seja, com o senso comum realista só é possível graças a estas alterações. O autor realça tanto a importância que os estudos sobre a paz têm para o surgimento de um conceito amplo de paz, desenvolvido por Johan Galtung, como o facto destes esta...


    Tatiana Azevedo Yeh


    Full Text Available Esse estudo buscou identificar os fatores que afetam o comportamento de consumo ecologicamente consciente (CCEC. Foram utilizadas duas amostras, uma com chineses e outra com brasileiros. Para análise dos dados utilizou-se técnica estatística descritiva, Teste t e regressão linear multivariada. Demonstrou-se, nas duas amostras, dois construtos comumente significativos para o CCEC: o próprio comportamento verde em si para realização de outros CCEC e os moderadores externos. Identificou-se que a baixa disponibilidade de produtos verdes entre os brasileiros é barreira à ser considerada para o fomento do CCEC no Brasil, que encontra-se na primeira fase de comportamento verde que é a compra. E que os chineses realizam todos os tipos de comportamento: compra, uso e reciclagem.

  13. (Sem saber e (com poder nos estudos organizacionais

    José Henrique de Faria

    Full Text Available Bacon afirma que saber é poder. Tragtenberg contesta. Essa discussão, na contemporaneidade, faz-se mais importante do que se possa imaginar. Por isso, o objetivo central deste artigo é verificar as relações entre saber e poder, na atualidade, levando em consideração o papel da ciência e dos elementos imediatos a ela relacionados. Quanto aos objetivos específicos deste estudo, destacam-se: · compreender o sentido da filosofia e da ciência e suas relações com a ideologia; · verificar como o discurso da neutralidade axiológica da ciência se apresenta como mito da modernidade e como se dá a presença da "fé" na filosofia e na ciência, na contemporaneidade; · refletir sobre a consolidação da ciência como força produtiva e/ou como mercadoria no atual sistema econômico; · destacar a importância do complexo industrial militar como financiador de grande parte dos atuais estudos científicos; · entender o processo de racionalização, avaliando a importância do pragmatismo e da burocracia universitária como afirmação da ciência na atualidade. O texto conclui que tanto é possível a existência de saber como poder (Bacon como a de não saber, mas com poder (Tragtenberg para compreendermos a relação entre saber e poder.

  14. O Zulliger no sistema compreensivo: um estudo de fidedignidade

    Anna Elisa de Villemor-Amaral

    Full Text Available Os testes psicológicos têm passado por verificações criteriosas de validade e precisão a fim de atender às exigências éticas e científicas. O objetivo desta pesquisa foi averiguar a precisão do Teste Zulliger no sistema compreensivo por meio do teste-reteste. Participaram do estudo 25 sujeitos, do sexo masculino, não pacientes, estudantes de teologia do interior de São Paulo. Utilizou-se um questionário para dados socioeconômico-familiar e o Zulliger. A aplicação dos instrumentos foi individual, durando cerca de 40 minutos, com intervalo de 5 meses entre teste-reteste. Dos protocolos, 25% foram recodificados por um juiz às cegas, obtendo-se índices satisfatórios de precisão. Foram selecionados 16 indicadores para se realizar as estatísticas descritivas e estudos de correlação com método de Pearson. Desses, dez alcançaram índices de precisão satisfatórios, entre 0,60-0,99; quatro tiveram uma precisão entre 0,40-0,60, todos com nível de significância entre 0,01 e 0,05. Os resultados foram satisfatórios e contribuíram para demonstrar a precisão do instrumento.

  15. Estudos cronotópicos em narrativas audiovisuais

    Egle Müller Spinelli


    Full Text Available O presente trabalho pretende aplicar o conceito de cronotopia de Bakhtin à análise de narrativas audiovisuais. Para tanto, será discutido o conceito de cronotopo bakhtiniano e sua relação com os estudos de Saussure, com o intuito de mostrar como os elementos cronotópicos podem estar ligados a contextos que vão além do enunciado, remetendo a mecanismos da enunciação. No estudo são analisados filmes que apresentam determinadas características semelhantes às dos principais tipos de cronotopia estabelecidos por Bakhtin: a da aventura, a do cotidiano e a autobiográfica, respectivamente correspondentes aos filmes Corra Lola, Corra (Tom Tykwer, 1998, Boca de Ouro (Nelson Pereira dos Santos, 1962 e Rashomon (Akira Kurosawa, 1950. Palavras-chave: cronotopia; enunciação; cinema; Bakhtin Abstract Chronotopic studies in audiovisual narratives - This paper proposes to apply Bakhtin's concept of chronotopia in an analysis of audiovisual discourse. To this end, it discusses the Bakhtin's postulation of the chronotope and its relation with the studies of Saussure in order to show how chronotopic elements may be connected to contexts that go beyond simple statements, suggesting mechanisms of enunciation. The films Run Lola, Run (Tom Tykwer, 1998, Boca de Ouro (Nelson Pereira dos Santos, 1962 and Rashomon (Akira Kurosawa, 1950 are used here to illustrate the principal chronotopic types established by Bakhtin, namely, adventure, everyday life and autobiography. Key words: chronotope; enunciation; cinema; Bakhtin

  16. O Zulliger no sistema compreensivo: um estudo de fidedignidade

    Anna Elisa de Villemor-Amaral

    Full Text Available Os testes psicológicos têm passado por verificações criteriosas de validade e precisão a fim de atender às exigências éticas e científicas. O objetivo desta pesquisa foi averiguar a precisão do Teste Zulliger no sistema compreensivo por meio do teste-reteste. Participaram do estudo 25 sujeitos, do sexo masculino, não pacientes, estudantes de teologia do interior de São Paulo. Utilizou-se um questionário para dados socioeconômico-familiar e o Zulliger. A aplicação dos instrumentos foi individual, durando cerca de 40 minutos, com intervalo de 5 meses entre teste-reteste. Dos protocolos, 25% foram recodificados por um juiz às cegas, obtendo-se índices satisfatórios de precisão. Foram selecionados 16 indicadores para se realizar as estatísticas descritivas e estudos de correlação com método de Pearson. Desses, dez alcançaram índices de precisão satisfatórios, entre 0,60-0,99; quatro tiveram uma precisão entre 0,40-0,60, todos com nível de significância entre 0,01 e 0,05. Os resultados foram satisfatórios e contribuíram para demonstrar a precisão do instrumento.

  17. Estudo sobre reciclagem de lâmpadas fluorescentes

    Danniele Miranda Bacila


    Full Text Available Lâmpadas fluorescentes (LF contêm mercúrio em sua composição, um metal pesado que pode causar danos à saúde e ao meio ambiente. As LF são amplamente consumidas no Brasil, porém o descarte correto de LF usadas não é amplamente divulgado e os índices de reciclagem são baixos. O objetivo deste estudo foi demonstrar a relevância do descarte adequado, avaliar as tecnologias de reciclagem e a destinação dos materiais, por meio de estudo comparativo entre Brasil e Alemanha. Através de visitas a recicladoras e análise das tecnologias adotadas nos dois países, foi verificado que no Brasil o vidro é destinado à indústria de cerâmica, enquanto que na Alemanha é destinado à fabricação de tubos para LF. Além disso, foi observado que o mercúrio apresenta diversas possibilidades de uso. Um ponto a ser explorado nos dois países, e de grande potencial para reciclagem, é a recuperação de terras raras do pó fosfórico presente nas LF. Tanto Brasil como Alemanha possuem oportunidades de melhoria na logística reversa de LF, por meio da qual se torna possível elevar os índices de reciclagem e reduzir os impactos ambientais causados pelo descarte inadequado de LF usadas.

  18. Laser-surface interactions

    Ganeev, Rashid A


    This book is about the interaction of laser radiation with various surfaces at variable parameters of radiation. As a basic principle of classification we chose the energetic or intensity level of interaction of laser radiation with the surfaces. These two characteristics of laser radiation are the most important parameters defining entire spectrum of the processes occurring on the surfaces during interaction with electromagnetic waves. This is a first book containing a whole spectrum of the laser-surface interactions distinguished by the ranges of used laser intensity. It combines the surface response starting from extremely weak laser intensities (~1 W cm-2) up to the relativistic intensities (~1020 W cm-2 and higher). The book provides the basic information about lasers and acquaints the reader with both common applications of laser-surface interactions (laser-related printers, scanners, barcode readers, discs, material processing, military, holography, medicine, etc) and unusual uses of the processes on t...

  19. Ceramic Laser Materials

    Guillermo Villalobos


    Full Text Available Ceramic laser materials have come a long way since the first demonstration of lasing in 1964. Improvements in powder synthesis and ceramic sintering as well as novel ideas have led to notable achievements. These include the first Nd:yttrium aluminum garnet (YAG ceramic laser in 1995, breaking the 1 KW mark in 2002 and then the remarkable demonstration of more than 100 KW output power from a YAG ceramic laser system in 2009. Additional developments have included highly doped microchip lasers, ultrashort pulse lasers, novel materials such as sesquioxides, fluoride ceramic lasers, selenide ceramic lasers in the 2 to 3 μm region, composite ceramic lasers for better thermal management, and single crystal lasers derived from polycrystalline ceramics. This paper highlights some of these notable achievements.

  20. Ceramic Laser Materials

    Sanghera, Jasbinder; Kim, Woohong; Villalobos, Guillermo; Shaw, Brandon; Baker, Colin; Frantz, Jesse; Sadowski, Bryan; Aggarwal, Ishwar


    Ceramic laser materials have come a long way since the first demonstration of lasing in 1964. Improvements in powder synthesis and ceramic sintering as well as novel ideas have led to notable achievements. These include the first Nd:yttrium aluminum garnet (YAG) ceramic laser in 1995, breaking the 1 KW mark in 2002 and then the remarkable demonstration of more than 100 KW output power from a YAG ceramic laser system in 2009. Additional developments have included highly doped microchip lasers, ultrashort pulse lasers, novel materials such as sesquioxides, fluoride ceramic lasers, selenide ceramic lasers in the 2 to 3 μm region, composite ceramic lasers for better thermal management, and single crystal lasers derived from polycrystalline ceramics. This paper highlights some of these notable achievements. PMID:28817044

  1. Dye laser chain for laser isotope separation

    Doizi, Denis; Jaraudias, Jean; Pochon, E.; Salvetat, G.


    Uranium enrichment by laser isotope separation uses a three step operation which requires four visible wavelengths to boost an individual U235 isotope from a low lying atomic energy level to an autoionizing state. The visible wavelengths are delivered by dye lasers pumped by copper vapor lasers (CVL). In this particular talk, a single dye chain consisting of a master oscillator and amplifier stages will be described and some of its performance given.

  2. Controlling Chaotic Lasers

    Gills, Zelda; Roy, Rajarshi


    Irregular fluctuations in intensity have long plagued the operation of a wide variety of solid-state lasers. We are exploring the possibility of exploiting rather than avoiding a laser's chaotic output. As an important step in that direction, we have applied a novel control technique to stabilize a solid state laser. By making small periodic changes in only one input parameter of the laser, we are able to stabilize complex periodic waveforms and steady state behavior in the laser output. We demonstrate the application of this approach in a diode pumped Nd:/YAG laser system.

  3. Lasers in periodontics.

    Elavarasu, Sugumari; Naveen, Devisree; Thangavelu, Arthiie


    Laser is one of the most captivating technologies in dental practice since Theodore Maiman in 1960 invented the ruby laser. Lasers in dentistry have revolutionized several areas of treatment in the last three and a half decades of the 20(th) century. Introduced as an alternative to mechanical cutting device, laser has now become an instrument of choice in many dental applications. Evidence suggests its use in initial periodontal therapy, surgery, and more recently, its utility in salvaging implant opens up a wide range of applications. More research with better designs are a necessity before lasers can become a part of dental armamentarium. This paper gives an insight to laser in periodontics.

  4. Laser cooling of solids

    Nemova, Galina


    Parallel to advances in laser cooling of atoms and ions in dilute gas phase, which has progressed immensely, resulting in physics Nobel prizes in 1997 and 2001, major progress has recently been made in laser cooling of solids. I compare the physical nature of the laser cooling of atoms and ions with that of the laser cooling of solids. I point out all advantages of this new and very promising area of laser physics. Laser cooling of solids (optical refrigeration) at the present time can be lar...

  5. LASIK - Laser Eye Surgery

    ... Uveitis Focus On Pediatric Ophthalmology Education Center Oculofacial Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center ... Uveitis Focus On Pediatric Ophthalmology Education Center Oculofacial Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center ...

  6. Laser Processing and Chemistry

    Bäuerle, Dieter


    This book gives an overview of the fundamentals and applications of laser-matter interactions, in particular with regard to laser material processing. Special attention is given to laser-induced physical and chemical processes at gas-solid, liquid-solid, and solid-solid interfaces. Starting with the background physics, the book proceeds to examine applications of lasers in “standard” laser machining and laser chemical processing (LCP), including the patterning, coating, and modification of material surfaces. This fourth edition has been enlarged to cover the rapid advances in the understanding of the dynamics of materials under the action of ultrashort laser pulses, and to include a number of new topics, in particular the increasing importance of lasers in various different fields of surface functionalizations and nanotechnology. In two additional chapters, recent developments in biotechnology, medicine, art conservation and restoration are summarized. Graduate students, physicists, chemists, engineers, a...

  7. Transmyocardial Laser Revascularization

    ... Vascular Access for Hemodialysis Ventricular Assist Devices Transmyocardial Laser Revascularization Like every other organ or tissue in ... bypass surgery, there is a procedure called transmyocardial laser revascularization, also called TMLR or TMR. TMLR cannot ...

  8. Wavelength sweepable laser source


    Wavelength sweepable laser source is disclosed, wherein the laser source is a semiconductor laser source adapted for generating laser light at a lasing wavelength. The laser source comprises a substrate, a first reflector, and a second reflector. The first and second reflector together defines...... and having a rest position, the second reflector and suspension together defining a microelectromechanical MEMS oscillator. The MEMS oscillator has a resonance frequency and is adapted for oscillating the second reflector on either side of the rest position.; The laser source further comprises electrical...... connections adapted for applying an electric field to the MEMS oscillator. Furthermore, a laser source system and a method of use of the laser source are disclosed....

  9. Laser in operative dentistry

    E. Yasini


    Full Text Available Today laser has a lot of usage in medicine and dentistry. In the field of dentistry, laser is used in soft tissue surgery, sterilization of canals (in root canal therapy and in restorative dentistry laser is used for cavity preparation, caries removal, sealing the grooves (in preventive dentistry, etching enamel and dentin, composite polymerization and removal of tooth sensitivity. The use of Co2 lasers and Nd: YAG for cavity preparation, due to creating high heat causes darkness and cracks around the region of laser radiation. Also due to high temperature of these lasers, pulp damage is inevitable. So today, by using the Excimer laser especially the argon floride type with a wavelength of 193 nm, the problem of heat stress have been solved, but the use of lasers in dentistry, especially for cavity preparation needs more researches and evaluations.

  10. Laser surgery - skin

    Surgery using a laser ... used is directly related to the type of surgery being performed and the color of the tissue ... Laser surgery can be used to: Close small blood vessels to reduce blood loss Remove warts , moles , sunspots, and ...

  11. Laser removal of tattoos.

    Kuperman-Beade, M; Levine, V J; Ashinoff, R


    Tattoos are placed for different reasons. A technique for tattoo removal which produces selective removal of each tattoo pigment, with minimal risk of scarring, is needed. Nonspecific methods have a high incidence of scarring, textural, and pigmentary alterations compared with the use of Q-switched lasers. With new advances in Q-switched laser technology, tattoo removal can be achieved with minimal risk of scarring and permanent pigmentary alteration. There are five types of tattoos: amateur, professional, cosmetic, medicinal, and traumatic. Amateur tattoos require less treatment sessions than professional multicolored tattoos. Other factors to consider when evaluating tattoos for removal are: location, age and the skin type of the patient. Treatment should begin by obtaining a pre-operative history. Since treatment with the Q-switched lasers is painful, use of a local injection with lidocaine or topical anaesthesia cream may be used prior to laser treatment. Topical broad-spectrum antibacterial ointment is applied immediately following the procedure. Three types of lasers are currently used for tattoo removal: Q-switched ruby laser (694 nm), Q-switched Nd:YAG laser (532 nm, 1064 nm), and Q-switched alexandrite laser (755 nm). The Q-switched ruby and alexandrite lasers are useful for removing black, blue and green pigments. The Q-switched 532 nm Nd:YAG laser can be used to remove red pigments and the 1064 nm Nd:YAG laser is used for removal of black and blue pigments. The most common adverse effects following laser tattoo treatment with the Q-switched ruby laser include textural change, scarring, and pigmentary alteration. Transient hypopigmentation and textural changes have been reported in up to 50 and 12%, respectively, of patients treated with the Q-switched alexandrite laser. Hyperpigmentation and textural changes are infrequent adverse effects of the Q-switched Nd:YAG laser and the incidence of hypopigmentary changes is much lower than with the ruby laser

  12. Tunable laser optics

    Duarte, FJ


    This Second Edition of a bestselling book describes the optics and optical principles needed to build lasers. It also highlights the optics instrumentation necessary to characterize laser emissions and focuses on laser-based optical instrumentation. The book emphasizes practical and utilitarian aspects of relevant optics including the essential theory. This revised, expanded, and improved edition contains new material on tunable lasers and discusses relevant topics in quantum optics.

  13. Laser cutting system

    Dougherty, Thomas J


    A workpiece cutting apparatus includes a laser source, a first suction system, and a first finger configured to guide a workpiece as it moves past the laser source. The first finger includes a first end provided adjacent a point where a laser from the laser source cuts the workpiece, and the first end of the first finger includes an aperture in fluid communication with the first suction system.

  14. CO2 laser modeling

    Johnson, Barry


    The topics covered include the following: (1) CO2 laser kinetics modeling; (2) gas lifetimes in pulsed CO2 lasers; (3) frequency chirp and laser pulse spectral analysis; (4) LAWS A' Design Study; and (5) discharge circuit components for LAWS. The appendices include LAWS Memos, computer modeling of pulsed CO2 lasers for lidar applications, discharge circuit considerations for pulsed CO2 lidars, and presentation made at the Code RC Review.

  15. Photonic bandgap fiber lasers and multicore fiber lasers for next generation high power lasers

    Shirakawa, A.; Chen, M.; Suzuki, Y.


    Photonic bandgap fiber lasers are realizing new laser spectra and nonlinearity mitigation that a conventional fiber laser cannot. Multicore fiber lasers are a promising tool for power scaling by coherent beam combination. © 2014 OSA.......Photonic bandgap fiber lasers are realizing new laser spectra and nonlinearity mitigation that a conventional fiber laser cannot. Multicore fiber lasers are a promising tool for power scaling by coherent beam combination. © 2014 OSA....

  16. Application of Various Lasers to Laser Trimming Resistance System

    SUN Ji-feng


    Though the laser trimming resistance has been an old laser machining industry for over 30 years, the development of technology brings new alternative lasers which can be used for the traditional machining. The paper describes application of various lasers to laser trimming resistance system including early traditional krypton arc lamp pumped Nd:YAG to laser, modern popular diode pumped solid state laser and the present advanced harmonic diode pumped solid state laser. Using the new alternative lasers in the laser trimming resistance system can dramatically improve the yields and equipment performance.

  17. Tuberculose e o estudo molecular da sua epidemiologia

    J. R. Pandolfi


    Full Text Available

    A existência de sistemas que possam diferenciar cepas de Mycobacterium tuberculosis epidemiologicamente relacionadas daquelas não relacionadas, são ferramentas importantes. A tuberculose é uma doença infecciosa, na qual técnicas de biologia molecular permitem a obtenção de informações muito difíceis ou impossíveis de serem alcançadas pela epidemiologia clássica. Um método de tipagem discriminatório, baseado no DNA genômico bacteriano, denominado RFLP (polimorfismo de comprimento de fragmentos de restrição, é empregado no estudo epidemiológico da tuberculose. Entretanto esta técnica é trabalhosa e sua substituição é uma tendência. Assim, outras seqüências têm sido usadas como marcadores epidemiológicos, como na Spoligotyping, a qual é baseada na PCR, com hibridização diferencial subseqüente dos produtos amplificados. O polimorfismo observado nas diferentes amostras é provavelmente produto de recombinação homóloga. A técnica de MIRU (mycobacterial interspersed repetitive unit é um sistema rápido e reprodutível, onde ocorre a geração de genótipos baseados no estudo de 12 loci contendo VNTRs (número variável de repetições em seqüência do complexo M. tuberculosis. Ela compara as cepas de áreas geográficas diferentes e permite o rastreamento do movimento de linhagens individuais, como no RFLP. Este tipo de abordagem permite a análise de maior número de cepas e a identificação de um número maior de focos de contaminação dentro da população, propiciando melhores maneiras de frear a transmissão da doença. Palavras-chave: Mycobacterium tuberculosis; tuberculose; epidemiologia molecular; genotipagem.

  18. Estudos de medicamentos biosimilares Studies on biosimilar medications

    Winston Bonetti Yoshida


    Full Text Available No Brasil, o registro de novos medicamentos é feito apenas quando a agência reguladora - Agência Nacional de Vigilância Sanitária (Anvisa - se satisfaz plenamente com as evidências de sua qualidade, eficácia e segurança, apresentadas por uma indústria farmacêutica que pleiteie esse registro. Com o vencimento de patentes, empresas farmacêuticas se sentem atraídas pela produção medicamentos biológicos chamados de biosimilares ou biogenéricos ou simplesmente genéricos, cuja aprovação pode resultar em redução de custos de tratamento. Mas é preciso que o biosimilar seja, pelo menos, igualmente eficaz e seguro e sem contaminantes em relação ao original. Consensos recentes apontam diretrizes para estabelecer critérios de eficácia e segurança desses medicamentos. Estudos pré-clínicos in vitro e in vivo, procedência da matéria-prima e estudos clínicos fase I, II e III são preconizados para registro do produto biosimilar no mercado internacional. As heparinas de baixo peso molecular encontram-se nessa situação. Nesta revisão, abordamos especificamente esse tipo de medicamento, o que pode servir de parâmetro para outros biosimilares.In Brazil, the registration of new drugs is carried out only when the regulatory agency (Anvisa, acronym in Portuguese is fully satisfied with the evidence of their quality, efficacy and safety, presented by a pharmaceutical industry that strive for this registration. With the patent expiration, pharmaceutical companies are attracted to produce biological medicines called biosimilar or biogenerics or simply generics, whose approval may result in reduced treatment costs. But it is necessary that the biosimilar be, at least, equally effective and safe and without contaminants in relation to the original. Recent consensus guidelines aim to establish criteria for efficacy and safety of these medicines. Preclinical studies in vitro and in vivo, the origin of raw materials and clinical studies


    KANESIRO, Lidiane Aparecida


    Full Text Available This study aimed to examine the partnership between the Swiss Company Nespresso and the Cooxupé Cooperative for the production of specialty coffee in the cerrado savannah, where the ones cooperatedCooxupé are the providers of these cafes. There were applied questionnaires for some producers with objectives question to evaluate to assess the difficulties in producing specialty coffee, to meet social demands, today almost mandatory when referring to products of high quality, is, generally know what you think of this partnership between the Cooperative Cooxupé and Nespresso. A search of bibliographic data was also used for reasons of this study. The results showed that the partnership was accepted by the producers, this partnership must be maintained and enhanced and that it should clarify the producers of the importance of investing in the environment. It can be verified that this work comes to be for the improvement of the partnership among the two companies involved in the study, and to conclude that the partnership was well accepts for the suppliers, could be perfected every year.Este trabalho teve por objetivo analisar a parceria firmada entre a Cooperativa Cooxupé e a Empresa suíça Nespresso para a produção de cafés especiais no cerrado mineiro, onde os próprios cooperados daCooxupé são os fornecedores destes cafés. Foram aplicados questionários com questões objetivas aos produtores da cooperativa com o intuito de avaliar as dificuldades em produzir cafés especiais, de cumprirem exigências sócio-ambientais, hoje praticamente obrigatórias quando se refere a produtos de qualidade, e saber o que acham desta parceria entre sua Cooperativa e a Nespresso. A pesquisa de dados bibliográficos também foi usada parafundamentação deste estudo. Os resultados obtidos mostraram que a parceria foi aceita pelos produtores; que tal parceria tem que ser mantida e aprimorada e que se deve esclarecer os produtores da importância em se

  20. Zeeman laser gyroscopes

    Azarova, V V; Golyaev, Yu D; Saveliev, I I [Open Joint-Stock Company M.F. Stel' makh Polyus Research Institute, Moscow (Russian Federation)


    The history of invention and development of Zeeman laser gyroscopes, specific features of their optical scheme and operation principle are described. The construction and element base of modern laser angular velocity sensors with Zeeman-based frequency biasing are considered. The problems and prospects of their development are discussed. (laser gyroscopes)

  1. Lasers for nonlinear microscopy.

    Wise, Frank


    Various versions of nonlinear microscopy are revolutionizing the life sciences, almost all of which are made possible because of the development of ultrafast lasers. In this article, the main properties and technical features of short-pulse lasers used in nonlinear microscopy are summarized. Recent research results on fiber lasers that will impact future instruments are also discussed.

  2. Laser power transmission

    Conway, Edmund J.


    An overview of previous studies related to laser power transmission is presented. Particular attention is given to the use of solar pumped lasers for space power applications. Three general laser mechanisms are addressed: photodissociation lasing driven by sunlight, photoexcitation lasing driven directly by sunlight, and photoexcitation lasing driven by thermal radiation.

  3. Laser Programs Highlights 1998

    Lowdermilk, H.; Cassady, C.


    This report covers the following topics: Commentary; Laser Programs; Inertial Confinement Fusion/National Ignition Facility (ICF/NIF); Atomic Vapor Laser Isotope Separation (AVLIS); Laser Science and Technology (LS&T); Information Science and Technology Program (IS&T); Strategic Materials Applications Program (SMAP); Medical Technology Program (MTP) and Awards.

  4. On g -ray laser


    We review various possibilities for realizing a g-ray laser. We conclude that, similar to the free-electron laser, it is practical to generate the g-ray laser by the stimulated emission of radiation from wiggling positrons channelled in a periodically bent crystal. It is the time to research this possi-bility both theoretically and experimentally with big efforts.

  5. LaserFest Celebration

    Dr. Alan Chodos; Elizabeth A. Rogan


    LaserFest was the yearlong celebration, during 2010, of the 50th anniversary of the demonstration of the first working laser. The goals of LaserFest were: to highlight the impact of the laser in its manifold commercial, industrial and medical applications, and as a tool for ongoing scientific research; to use the laser as one example that illustrates, more generally, the route from scientific innovation to technological application; to use the laser as a vehicle for outreach, to stimulate interest among students and the public in aspects of physical science; to recognize and honor the pioneers who developed the laser and its many applications; to increase awareness among policymakers of the importance of R&D funding as evidenced by such technology as lasers. One way in which LaserFest sought to meet its goals was to encourage relevant activities at a local level all across the country -- and also abroad -- that would be identified with the larger purposes of the celebration and would carry the LaserFest name. Organizers were encouraged to record and advertise these events through a continually updated web-based calendar. Four projects were explicitly detailed in the proposals: 1) LaserFest on the Road; 2) Videos; 3) Educational material; and 4) Laser Days.

  6. Laser bottom hole assembly

    Underwood, Lance D; Norton, Ryan J; McKay, Ryan P; Mesnard, David R; Fraze, Jason D; Zediker, Mark S; Faircloth, Brian O


    There is provided for laser bottom hole assembly for providing a high power laser beam having greater than 5 kW of power for a laser mechanical drilling process to advance a borehole. This assembly utilizes a reverse Moineau motor type power section and provides a self-regulating system that addresses fluid flows relating to motive force, cooling and removal of cuttings.

  7. Diode laser and endoscopic laser surgery.

    Sullins, Kenneth E


    Two functionally important differences exist between the diode laser and the carbon dioxide (CO2) laser (used more commonly in small animal surgery). Diode laser energy is delivered through a quartz fiber instead of being reflected through an articulated arm or waveguide. Quartz fibers are generally more flexible and resilient than waveguides and can be inserted through an endoscope for minimally invasive procedures. Laser-tissue interaction is the other significant difference. The CO2 laser is completely absorbed by water, which limits the effect to visible tissue. The diode wavelength is minimally absorbed by water and may affect tissue as deep as 10 mm below the surface in the free-beam mode. With proper respect for the tissue effect, these differences can be used to the advantage of the patient.

  8. Um estudo de construção da personagem a partir do movimento corporal

    Ligia Losada Tourinho


    Resumo: Esta pesquisa apresenta um estudo sistemático sobre a construção da personagem nas Artes Cênicas, pelo prisma do movimento corporal, utilizando como principal suporte teórico e prático os estudos da Coreologia de Rudolf Von Laban e da Técnica de Stanislavski. Tomamos como base para a fundamentação teórica a idéia de o homem ser uma corporeidade, constituída pela Gestalt CORPO-MENTE-ESPÍRITO, presente nos estudos de Merleau-Ponty, nas consciências corporais e em todos aqueles que acred...

  9. Um estudo de construção da personagem a partir do movimento corporal

    Ligia Losada Tourinho


    Esta pesquisa apresenta um estudo sistemático sobre a construção da personagem nas Artes Cênicas, pelo prisma do movimento corporal, utilizando como principal suporte teórico e prático os estudos da Coreologia de Rudolf Von Laban e da Técnica de Stanislavski. Tomamos como base para a fundamentação teórica a idéia de o homem ser uma corporeidade, constituída pela Gestalt CORPO-MENTE-ESPÍRITO, presente nos estudos de Merleau-Ponty, nas consciências corporais e em todos aqueles que acreditam na ...

  10. O texto traduzido sob a perspectiva do avaliador: um estudo exploratório

    Camila Nathalia de Oliveira Braga


    Esta tese busca contribuir para os Estudos da Tradução, mais especificamente os estudos voltados para a avaliação de traduções, ao apresentar um estudo sobre o texto traduzido sob a perspectiva do avaliador. Para tanto, dezoito avaliadores (seis pesquisadores da área de Engenharia, seis linguistas / linguistas aplicados e seis tradutores profissionais) receberam a tarefa de avaliar oito traduções para o inglês de um resumo de uma tese da área de rejeitos radioativos escrito originalmente em p...

  11. Considerações metodológicas sobre o estudo de caso na pesquisa em psicoterapia

    Serralta, Fernanda Barcellos; Nunes, Maria Lúcia Tiellet; Eizirik,Cláudio Laks


    O presente artigo faz uma revisão crítica da literatura acerca da aplicabilidade do estudo de caso na pesquisa em psicoterapia: a) apresenta as características do estudo de caso como estratégia de pesquisa; b) aborda a importância dos delineamentos de caso único no estudo do processo terapêutico; c) discute estatégias para aumentar a fidedignidade e validade dos estudos de caso; d) apresenta exemplos de estudos de caso oriundos da atual geração de pesquisa empírica em psicoterapia e psicanáli...


    Fernando Cesar Almeida Silva


    Full Text Available Este artigo tem como objetivo descrever como foi realizado um estudo da maturidade dos processos CobiT em uma empresa do setor de energia elétrica do Brasil. Foi feita uma pesquisa onde os integrantes do Comitê de Tecnologia de Informação desta empresa informam sua percepção do nível de maturidade dos diversos processos existentes no CobiT. É realizada uma análise dos resultados onde é considerado o contexto no qual a empresa se insere. Para finalizar é proposto um sistema baseado no PDCA com o objetivo de aprimorar os processos que receberam classificação de avaliação mais baixa. A priorização de quais processos devem ser aprimorados primeiro, é baseada em critérios que levam em consideração os principais controles de ambiente do PCAOB, uma vez que esta empresa é auditada regularmente devido às obrigatoriedades da lei Sarbanes-Oxley.


    Fabio Lamartine Barbosa Toledo

    Full Text Available RESUMO O presente artigo analisa o índice de especialização e sua relação com inovação, internacionalização e a qualificação. Limitando-se a alguns setores inseridos nos clusters tecnológicos das regiões de Florianópolis/SC, Recife/PE, Região do Porto/Portugal e Região da Cataluña/Espanha, buscou-se verificar como o desenvolvimento da inovação (patentes submetidas, a internacionalização (volume de exportação e a qualificação (mestres e doutores nestas regiões relaciona-se com o índice de especialização das mesmas. Utilizou-se neste estudo um recorte longitudinal, no qual a evolução do índice de especialização foi analisado ao longo de um período de quatro anos e confrontado com os indicadores: qualificação, internacionalização e inovação. Foram formuladas três hipóteses, as quais foram testadas por meio do tratamento dos dados obtidos nas regiões dos quatro clusters pesquisados.

  14. Raiva humana: estudo neuropatológico de trinta casos

    R. V. C. Assis


    Full Text Available O estudo epidemiológico e neuropatológico concernente a trinta autópsias de encefalite rábica foi realizado, tendo sido os dados obtidos comparados com aqueles da literatura. Não houve relação estatística entre a topografia lesional e o local da mordida, entre o período de incubação ou a duração da doença e a presença ou ausência de inclusões virais (IV assim como entre a intensidade do processo inflamatorio (PI e a presença de IV. A dispersão do PI e das IV através o SNC foi diretamente proporcional à sua intensidade. A estrutura mais freqüentemente comprometida pelo PI foi o mesencéfalo, seguido pelo bulbo, ponte e medula espinhal. A estrutura mais intensamente afetada foi o bulbo. As IV foram particularmente proeminentes no hipocampo e cerebelo.

  15. Trabalho e riscos de adoecimento: um estudo entre policiais civis

    Vânia Cristine Cavalcante Anchieta

    Full Text Available Este estudo teve como objetivo avaliar a percepção que os policiais civis do DF têm sobre o seu contexto de trabalho, suas exigências, assim como as vivências e os problemas físicos, psicológicos e sociais causados pelo trabalho, procurando fazer inferências sobre as estratégias de mediação utilizadas para evitar o sofrimento e os riscos de adoecimento. Foi aplicado o Inventário do Trabalho e Riscos de Adoecimento (ITRA em 160 policiais civis, homens e mulheres, recém empossados na Instituição (tempo médio de oito meses de ingresso na Instituição. Os resultados indicaram que, apesar de não ficarem evidentes danos graves à saúde do policial novato, há riscos de acontecerem falhas nas estratégias de mediação em relação a fatores que levam ao adoecimento.

  16. Estudo de usuários on line

    Bruno Macedo Nathansohn


    Full Text Available Trata-se de um estudo de usuários baseado na perspectiva da responsabilidade social da Ciência da Informação, considerando um agregado de informação disponível na Internet. O objetivo foi o levantamento do perfil dos usuários, para detectar suas preferências em relação ao sítio, assim como a investigação sobre o uso que se faz de um espaço que produz informação política, econômica e social. Para tanto, foram desenvolvidos mecanismos de interatividade para que, ao mesmo tempo em que houvesse a coleta de dados por parte do profissional da informação proporcionasse a participação, por parte dos usuários, para a possibilidade de transformar a estrutura desse agregado. Processo que se baseou na metodologia da Pesquisa-Ação, identificando e apresentando as barreiras na comunicação, como resultado final do processo de intervenção científica.


    Thiago de Almeida Santos


    Full Text Available Este trabalho, relacionado com o evento sísmico de 16 de Setembro de 2015, em Illapel, Chile, foca na análise de variações geomagnéticas, principalmente na caracterização e situação em que se dão, a fim de contribuir para uma melhor compreensão dos processos físicos envolvidos no acoplamento Litosfera-Atmosfera-Ionosfera (LAI. Para isto, foram utilizados registros de magnetômetros fluxgate medidos em superfície fornecido pela rede EMBRACE. A metodologia de análise consiste na decomposição do sinal por bandas de frequência, isto é, Decomposição de Modo Empírico (EMD. O resultado alcançado no momento é a caracterização de efeitos magnéticos co-sismogênicos em território brasileiro causados pelo evento sísmico citado. Portanto, estudos como este se mostram indispensáveis e importantes não apenas no ponto de vista científico, mas também pela possibilidade de contribuição para uma futura condição de previsão e de potencial de alerta de catástrofes.

  18. Do Antissocialismo ao Anticapitalismo: um estudo sobre a Rerum Novarum

    Claudinei Magno Magre Mendes


    Full Text Available O objetivo deste artigo é examinar o processo de constituição do anticapitalismo por meio da análise da Rerum Novarum, a primeira encíclica social. Comparando esta com as encíclicas anteriores do século XIX, pudemos estabelecer o que ela trouxe de novidade no que diz respeito ao combate que a Igreja travava contra o socialismo. Com essa comparação, foi possível caracterizar a postura anticapitalista, confrontando a nossa maneira de concebê-la com as demais. Para o exame da Rerum Novarum foi igualmente importante analisar alguns estudos referentes a ela, tanto os que apareceram logo após a sua publicação como os que foram realizados em décadas mais recentes. Como conclusão, definimos o anticapitalismo como uma atitude que somente poderia ter surgido em condições sociais e políticas bastante particulares e que apenas apareceram em fins do século XIX.

  19. Estudo retrospectivo da peste humana no Nordeste oriental do Brasil

    Dalva A. Mello


    Full Text Available Utilizando dados do Departamento Nacional de Endemias Rurais, o autor faz um estudo retrospectivo da peste humana no Nordeste Oriental do Brasil no período de 1935-1967. Os aspectos epidemiológicos abordados foram os seguintes: morbidade, mortalidade, letalidade, "point" epidêmicos, tendência secular e variações mensais. Os coeficientes de morbidade e mortalidade variaram muito. A letalidade apresentou-se bastante alta. Dez anos de "point" epidêmicos foram registrados no periodo estudado. A análise estatística dos casos distribuídos por mês mostrou que a peste humana atinge o pcnto máximo na estação sêca. Ficou demonstrada urna variação cíclica da doença, em que aumentos e decréscimos ocorrem em períodos que variam de 6 a 12 anos.

  20. Estudo da auditoria de contas em um hospital de ensino

    Gabriela Favaro Faria Guerrer


    Full Text Available RESUMOObjetivos:verificar os itens componentes das contas hospitalares, conferidos por enfermeiros auditores, que mais recebem ajustes no momento da pré-análise; identificar o impacto dos ajustes no faturamento das contas analisadas por enfermeiros e médicos auditores e identificar as glosas relacionadas aos itens conferidos pela equipe de auditoria.Método:pesquisa quantitativa exploratória, descritiva, do tipo estudo de caso único.Resultados:após a análise de 2.613 contas constatou-se que o item mais incluído por enfermeiros foram gases (90,5% e o mais excluído medicamentos de internação (41,2%. Materiais de hemodinâmica; gases e equipamentos foram os que mais impactaram nos ajustes positivos. Os ajustes negativos decorreram de lançamentos indevidos nas contas e não geraram prejuízos de faturamento. Do total de glosas 52,24% referiu-se à pré-análise dos enfermeiros e 47,76% a dos médicos.Conclusão:a presente investigação do processo de pré-análise fornece subsídios que contribuem para o avanço no conhecimento sobre a auditoria de contas hospitalares.

  1. The use of ablative lasers in the treatment of facial melasma O uso de lasers ablativos no tratamento do melasma facial

    Orlando Oliveira de Morais


    Full Text Available Melasma represents a pigmentary disorder that is difficult to treat. This study aims to broadly review the use of ablative lasers (Er:YAG and CO2 in the treatment of melasma, presenting the level of evidence of studies published to date. A total of 75 patients were enrolled in four case series studies (n=39, one controlled clinical trial (n=6 and one randomized controlled clinical trial (n=30. Studies on the Er:YAG laser showed better results with the use of short square-shaped pulses, which determined low rates of post-inflammatory hyperpigmentation and long-lasting maintenance of results. Likewise, studies on the CO2 laser proved the benefits of short pulse duration along with low-density energy. Post-treatment maintenance with the use of antipigmenting creams was necessary and effective to sustain long-term results. Ablative lasers may represent another useful and effective tool against melasma. Postinflammatory hyperpigmentation and difficulty in sustaining long-term results still represent the main limitations to a broader use of ablative lasers. Based on actual evidence, the use of this technology should be restricted to patients with recalcitrant disease. Further studies will help establish optimal laser parameters and treatment regimens.O melasma representa desordem pigmentar de difícil tratamento. O presente estudo tem como propósito apresentar ampla revisão da literatura acerca do uso de laser ablativos (Er:YAG e CO2 no tratamento do melasma, estabelecendo o nível de evidência dos estudos publicados até o instante. Um total de 75 pacientes foram envolvidos entre quatro séries de casos (n=39, um ensaio clínico controlado (n=6 e um ensaio clínico controlado e randomizado (n=30. Os estudos acerca do laser de Er:YAG demonstraram melhores resultados com o uso de pulsos de forma quadrada, os quais determinaram menores taxas de hiperpigmentação pós-inflamatória. Ademais, os estudos com laser de CO2 também demonstraram benef

  2. Introduction to laser technology

    Hitz, C Breck; Hecht, Jeff; Hitz, C Breck; John Wiley & Sons


    Electrical Engineering Introduction to Laser Technology , Third Edition. Would you like to know how a laser works, and how it can be modified for your own specific tasks? This intuitive third edition-previously published as Understanding Laser Technology , First and Second Editions-introduces engineers, scientists, technicians, and novices alike to the world of modern lasers, without delving into the mathematical details of quantum electronics. It is the only introductory text on the market today that explains the underlying physics and engineering applicable to all lasers. A unique combinatio.

  3. Lasers In Dentistry

    Prasanth. S


    Full Text Available The uses of Lasers in dentistry have revolutionized several areas of treatment in the last three & a half decades of the 20th century. Initially it was used for ablating the hard tissues for acid etch treatment. Later Lasers were used for cutting, coagulation & cauterization of the soft tissues. It is also been used for the diagnosis of carious lesions& to test pulp vitality with Doppler. There are more than 40 uses for Laser. Initially Lasers were very expensive, but now they have become much cheaper. Portable models are available which have increased its versatility. Lasers will be the main weapon in the armamentarium of the dental surgeons.

  4. Tunable laser applications

    Duarte, FJ


    Introduction F. J. Duarte Spectroscopic Applications of Tunable Optical Parametric Oscillators B. J. Orr, R. T. White, and Y. He Solid-State Dye Lasers Costela, I. García-Moreno, and R. Sastre Tunable Lasers Based on Dye-Doped Polymer Gain Media Incorporating Homogeneous Distributions of Functional Nanoparticles F. J. Duarte and R. O. James Broadly Tunable External-Cavity Semiconductor Lasers F. J. Duarte Tunable Fiber Lasers T. M. Shay and F. J. Duarte Fiber Laser Overview and Medical Applications

  5. Coherent laser beam combining

    Brignon, Arnaud


    Recently, the improvement of diode pumping in solid state lasers and the development of double clad fiber lasers have allowed to maintain excellent laser beam quality with single mode fibers. However, the fiber output power if often limited below a power damage threshold. Coherent laser beam combining (CLBC) brings a solution to these limitations by identifying the most efficient architectures and allowing for excellent spectral and spatial quality. This knowledge will become critical for the design of the next generation high-power lasers and is of major interest to many industrial, environme

  6. Photoionization in alkali lasers.

    Knize, R J; Zhdanov, B V; Shaffer, M K


    We have calculated photoionization rates in alkali lasers. The photoionization of alkali atoms in the gain medium of alkali lasers can significantly degrade the laser performance by reducing the neutral alkali density and with it the gain. For a ten atmosphere Rb laser and a Cs exciplex laser, the photoionization induced alkali atom loss rates are greater than 10(5) sec(-1). These high loss rates will quickly deplete the neutral alkali density, reducing gain, and may require fast, possibly, supersonic flow rates to sufficiently replenish the neutral medium for CW operation.

  7. Laser Diode Ignition (LDI)

    Kass, William J.; Andrews, Larry A.; Boney, Craig M.; Chow, Weng W.; Clements, James W.; Merson, John A.; Salas, F. Jim; Williams, Randy J.; Hinkle, Lane R.


    This paper reviews the status of the Laser Diode Ignition (LDI) program at Sandia National Labs. One watt laser diodes have been characterized for use with a single explosive actuator. Extensive measurements of the effect of electrostatic discharge (ESD) pulses on the laser diode optical output have been made. Characterization of optical fiber and connectors over temperature has been done. Multiple laser diodes have been packaged to ignite multiple explosive devices and an eight element laser diode array has been recently tested by igniting eight explosive devices at predetermined 100 ms intervals.

  8. Quantum well lasers

    Zory, Jr, Peter S; Kelley, Paul


    This book provides the information necessary for the reader to achieve a thorough understanding of all aspects of QW lasers - from the basic mechanism of optical gain, through the current technolgoical state of the art, to the future technologies of quantum wires and quantum dots. In view of the growing importance of QW lasers, this book should be read by all those with an active interest in laser science and technology, from the advanced student to the experienced laser scientist.* The first comprehensive book-length treatment of quantum well lasers* Provides a detailed treatment

  9. Semiconductor nanowire lasers

    Eaton, Samuel W.; Fu, Anthony; Wong, Andrew B.; Ning, Cun-Zheng; Yang, Peidong


    The discovery and continued development of the laser has revolutionized both science and industry. The advent of miniaturized, semiconductor lasers has made this technology an integral part of everyday life. Exciting research continues with a new focus on nanowire lasers because of their great potential in the field of optoelectronics. In this Review, we explore the latest advancements in the development of nanowire lasers and offer our perspective on future improvements and trends. We discuss fundamental material considerations and the latest, most effective materials for nanowire lasers. A discussion of novel cavity designs and amplification methods is followed by some of the latest work on surface plasmon polariton nanowire lasers. Finally, exciting new reports of electrically pumped nanowire lasers with the potential for integrated optoelectronic applications are described.

  10. ORION laser target diagnostics.

    Bentley, C D; Edwards, R D; Andrew, J E; James, S F; Gardner, M D; Comley, A J; Vaughan, K; Horsfield, C J; Rubery, M S; Rothman, S D; Daykin, S; Masoero, S J; Palmer, J B; Meadowcroft, A L; Williams, B M; Gumbrell, E T; Fyrth, J D; Brown, C R D; Hill, M P; Oades, K; Wright, M J; Hood, B A; Kemshall, P


    The ORION laser facility is one of the UK's premier laser facilities which became operational at AWE in 2010. Its primary mission is one of stockpile stewardship, ORION will extend the UK's experimental plasma physics capability to the high temperature, high density regime relevant to Atomic Weapons Establishment's (AWE) program. The ORION laser combines ten laser beams operating in the ns regime with two sub ps short pulse chirped pulse amplification beams. This gives the UK a unique combined long pulse/short pulse laser capability which is not only available to AWE personnel but also gives access to our international partners and visiting UK academia. The ORION laser facility is equipped with a comprehensive suite of some 45 diagnostics covering optical, particle, and x-ray diagnostics all able to image the laser target interaction point. This paper focuses on a small selection of these diagnostics.

  11. Alternate laser fusion drivers

    Pleasance, L.D.


    Over the past few years, several laser systems have been considered as possible laser fusion drivers. Recently, there has been an increasing effort to evaluate these systems in terms of a reactor driver application. The specifications for such a system have become firmer and generally more restrictive. Several of the promising candidates such as the group VI laser, the metal vapor excimers and some solid state lasers can be eliminated on the basis of inefficiency. New solid state systems may impact the long range development of a fusion driver. Of the short wavelength gas lasers, the KrF laser used in conjunction with Raman compression and pulse stacking techniques is the most promising approach. Efficiencies approaching 10% may be possible with this system. While technically feasible, these approaches are complex and costly and are unsatisfying in an aethetic sense. A search for new lasers with more compelling features is still needed.

  12. Laser Applications in Orthodontics

    Heidari, Somayeh; Torkan, Sepideh


    A laser is a collimated single wavelength of light which delivers a concentrated source of energy. Soon after different types of lasers were invented, investigators began to examine the effects of different wavelengths of laser energy on oral tissues, routine dental procedures and experimental applications. Orthodontists, along with other specialist in different fields of dentistry, can now benefit from several different advantages that lasers provide during the treatment process, from the beginning of the treatment, when separators are placed, to the time of resin residues removal from the tooth surface at the end of orthodontic treatment. This article outlines some of the most common usages of laser beam in orthodontics and also provides a comparison between laser and other conventional method that were the standard of care prior to the advent of laser in this field. PMID:25606324

  13. Lasers in orthodontics

    Nalcaci, Ruhi; Cokakoglu, Serpil


    Many types of dental lasers are currently available that can be efficiently used for soft and hard tissue applications in the field of orthodontics. For achieving the desired effects in the target tissue, knowledge of laser characteristics such as power, wavelength and timing, is necessary. Laser therapy is advantageous because it often avoids bleeding, can be pain free, is non-invasive and is relatively quick. The high cost is its primary disadvantage. It is very important to take the necessary precautions to prevent possible tissue damage when using laser dental systems. Here, we reviewed the main types and characteristics of laser systems used in dental practice and discuss the applications of lasers in orthodontics, harmful effects and laser system safety. PMID:24966719

  14. Lasers in materials science

    Ossi, Paolo; Zhigilei, Leonid


    This book covers various aspects of lasers in materials science, including a comprehensive overview on basic principles of laser-materials interactions and applications enabled by pulsed laser systems.  The material is organized in a coherent way, providing the reader with a harmonic architecture. While systematically covering the major current and emerging areas of lasers processing applications, the Volume provides examples of targeted modification of material properties achieved through careful control of the processing conditions and laser irradiation parameters. Special emphasis is placed on specific strategies aimed at nanoscale control of material structure and properties to match the stringent requirements of modern applications.  Laser fabrication of novel nanomaterials, which expands to the domains of photonics, photovoltaics, sensing, and biomedical applications, is also discussed in the Volume. This book assembles chapters based on lectures delivered at the Venice International School on Lasers...

  15. Flexible Laser Metal Cutting

    Villumsen, Sigurd; Jørgensen, Steffen Nordahl; Kristiansen, Morten


    This paper describes a new flexible and fast approach to laser cutting called ROBOCUT. Combined with CAD/CAM technology, laser cutting of metal provides the flexibility to perform one-of-a-kind cutting and hereby realises mass production of customised products. Today’s laser cutting techniques...... possess, despite their wide use in industry, limitations regarding speed and geometry. Research trends point towards remote laser cutting techniques which can improve speed and geometrical freedom and hereby the competitiveness of laser cutting compared to fixed-tool-based cutting technology...... such as punching. This paper presents the concepts and preliminary test results of the ROBOCUT laser cutting technology, a technology which potentially can revolutionise laser cutting....

  16. Mode selection laser


    The invention relates to a semiconductor mode selection laser, particularly to a VCSEL laser (200) having mode selection properties. The mode selection capability of the laser is achieved by configuring one of the reflectors (15,51) in the resonance cavity so that a reflectivity of the reflector...... (15) varies spatially in one dimension or two dimensions. Accordingly, the reflector (15) with spatially varying reflectivity is part both of the resonance cavity and the mode selection functionality of the laser. A plurality of the lasers configured with different mode selectors, i.e. different...... spatial reflector variations, may be combined to generate a laser beam containing a plurality of orthogonal modes. The laser beam may be injected into a few- mode optical fiber, e.g. for the purpose of optical communication. The VCSEL may have intra-cavity contacts (31,37) and a Tunnel junction (33...

  17. Nanofabrication with pulsed lasers.

    Kabashin, Av; Delaporte, Ph; Pereira, A; Grojo, D; Torres, R; Sarnet, Th; Sentis, M


    An overview of pulsed laser-assisted methods for nanofabrication, which are currently developed in our Institute (LP3), is presented. The methods compass a variety of possibilities for material nanostructuring offered by laser-matter interactions and imply either the nanostructuring of the laser-illuminated surface itself, as in cases of direct laser ablation or laser plasma-assisted treatment of semiconductors to form light-absorbing and light-emitting nano-architectures, as well as periodic nanoarrays, or laser-assisted production of nanoclusters and their controlled growth in gaseous or liquid medium to form nanostructured films or colloidal nanoparticles. Nanomaterials synthesized by laser-assisted methods have a variety of unique properties, not reproducible by any other route, and are of importance for photovoltaics, optoelectronics, biological sensing, imaging and therapeutics.

  18. ORION laser target diagnostics

    Bentley, C. D.; Edwards, R. D.; Andrew, J. E.; James, S. F.; Gardner, M. D.; Comley, A. J.; Vaughan, K.; Horsfield, C. J.; Rubery, M. S.; Rothman, S. D.; Daykin, S.; Masoero, S. J.; Palmer, J. B.; Meadowcroft, A. L.; Williams, B. M.; Gumbrell, E. T.; Fyrth, J. D.; Brown, C. R. D.; Hill, M. P.; Oades, K. [Plasma Physics Department, Atomic Weapons Establishment, Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom); and others


    The ORION laser facility is one of the UK's premier laser facilities which became operational at AWE in 2010. Its primary mission is one of stockpile stewardship, ORION will extend the UK's experimental plasma physics capability to the high temperature, high density regime relevant to Atomic Weapons Establishment's (AWE) program. The ORION laser combines ten laser beams operating in the ns regime with two sub ps short pulse chirped pulse amplification beams. This gives the UK a unique combined long pulse/short pulse laser capability which is not only available to AWE personnel but also gives access to our international partners and visiting UK academia. The ORION laser facility is equipped with a comprehensive suite of some 45 diagnostics covering optical, particle, and x-ray diagnostics all able to image the laser target interaction point. This paper focuses on a small selection of these diagnostics.

  19. Raman fiber lasers

    Supradeepa, V. R.; Feng, Yan; Nicholson, Jeffrey W.


    High-power fiber lasers have seen tremendous development in the last decade, with output powers exceeding multiple kilowatts from a single fiber. Ytterbium has been at the forefront as the primary rare-earth-doped gain medium owing to its inherent material advantages. However, for this reason, the lasers are largely confined to the narrow emission wavelength region of ytterbium. Power scaling at other wavelength regions has lagged significantly, and a large number of applications rely upon the diversity of emission wavelengths. Currently, Raman fiber lasers are the only known wavelength agile, scalable, high-power fiber laser technology that can span the wavelength spectrum. In this review, we address the technology of Raman fiber lasers, specifically focused on the most recent developments. We will also discuss several applications of Raman fiber lasers in laser pumping, frequency conversion, optical communications and biology.

  20. Laser physics and physiology.

    Pierce, L A


    Laser light begins when an excited and unstable electron moves from its unstable state back to a more stable state producing energy in the form of a photon. Laser light is coherent which means that the light waves move in phase together in space and time. Laser light is monochromatic which means it is comprised of only one color or wavelength. Laser light is also collimated which means it is perfectly parallel and travels in a single direction with very little divergence. Medical lasers fall in the infrared and visible as well as ultraviolet portion of the electromagnetic spectrum and are available at different wavelengths. The wavelength of each laser partially determines the effect it will have on tissue. A specific wavelength or color can be used to selectively target a specific tissue such as hemoglobin, water, or melanin. Heat is produced by the laser, destroying the targeted tissues.

  1. Tunable lasers for waste management photochemistry applications. [Dye lasers, excimer lasers, IR lasers

    Finch, F.T. (comp.)


    A review of lasers with potential photochemical applications in waste management indicates that dye lasers, as a class, can provide tunable laser output through the visible and near-uv regions of the spectrum of most interest to photochemistry. Many variables can affect the performance of a specific dye laser, and the interactions of these variables, at the current state of the art, are complex. The recent literature on dye-laser characteristics has been reviewed and summarized, with emphasis on those parameters that most likely will affect the scaling of dye lasers in photochemical applications. Current costs are reviewed and correlated with output power. A new class of efficient uv lasers that appear to be scalable in both energy output and pulse rate, based on rare-gas halide excimers and similar molecules, is certain to find major applications in photochemistry. Because the most important developments are too recent to be adequately described in the literature or are the likely outcome of current experiments, the basic physics underlying the class of excimer lasers is described. Specific cost data are unavailable, but these new gas lasers should reflect costs similar to those of existing gas lasers, in particular, the pulsed CO/sub 2/ lasers. To complete the survey of tunable-laser characteristics, the technical characteristics of the various classes of lasers in the ir are summarized. Important developments in ir laser technology are being accelerated by isotope-separation research, but, initially at least, this portion of the spectrum is least likely to receive emphasis in waste-management-oriented photochemistry.

  2. Lasers in space

    Michaelis, M. M.; Forbes, A.; Bingham, R.; Kellett, B. J.; Mathye, A.


    A variety of laser applications in space, past, present, future and far future are reviewed together with the contributions of some of the scientists and engineers involved, especially those that happen to have South African connections. Historically, two of the earliest laser applications in space, were atmospheric LIDAR and lunar ranging. These applications involved atmospheric physicists, several astronauts and many of the staff recruited into the Soviet and North American lunar exploration programmes. There is a strong interest in South Africa in both LIDAR and lunar ranging. Shortly after the birth of the laser (and even just prior) theoretical work on photonic propulsion and space propulsion by laser ablation was initiated by Georgii Marx, Arthur Kantrowitz and Eugen Saenger. Present or near future experimental programs are developing in the following fields: laser ablation propulsion, possibly coupled with rail gun or gas gun propulsion; interplanetary laser transmission; laser altimetry; gravity wave detection by space based Michelson interferometry; the de-orbiting of space debris by high power lasers; atom laser interferometry in space. Far future applications of laser-photonic space-propulsion were also pioneered by Carl Sagan and Robert Forward. They envisaged means of putting Saenger's ideas into practice. Forward also invented a laser based method for manufacturing solid antimatter or SANTIM, well before the ongoing experiments at CERN with anti-hydrogen production and laser-trapping. SANTIM would be an ideal propellant for interstellar missions if it could be manufactured in sufficient quantities. It would be equally useful as a power source for the transmission of information over light year distances. We briefly mention military lasers. Last but not least, we address naturally occurring lasers in space and pose the question: "did the Big Bang lase?"

  3. Optical coatings for fiber lasers

    HONG Dong-mei; ZHU Zhen; YUE Wei


    Fiber laser is the future development direction for the high energy lasers. This paper describs two kinds of optical coatings for fiber laser, including long and short wave pass filters. The one characteristic of fiber laser coatings lies in that coatings should separate two closely wavelength light including laser pump wavelength (980 nm) and laser irradiation wavelength(1 050~1 100 nm). At the same time, the coatings should have high laser damage threshold.

  4. Estudo do fluxo salivar, status periodontal e prevalência de lesões orais de doentes VIH1 e VIH2 naives: estudo seccional cruzado

    Ferreira, Cristina Gutierrez Castanheira


    Tese de mestrado, Medicina Dentária, Universidade de Lisboa, Faculdade de Medicina Dentária, 2013 Objetivo: Identificar alterações do fluxo salivar estimulado, alterações periodontais e caracterizar padrões de doença oral associados ou não à infecção por VIH em doentes VIH1 e VIH2 naives. Desenho de estudo: Estudo Observacional Seccional Cruzado Materiais e métodos: A amostra foi constituída por 70 participantes, (N=70) dos quais 27 VIH1 e 24 VIH2 naives (sem terapia anti-retroviral) recru...


    Juliana Celeste de Matos Braga; Luciano Pereira Zille


    ... estratégias de enfrentamento de taxistas que atuam na cidade de Belo Horizonte/MG. Em termos metodológicos, trata-se de um estudo descritivo-explicativo, com abordagem quantitativa e qualitativa, envolvendo 458 taxistas...

  6. Lesões esportivas: um estudo com atletas do basquetebol bauruense

    Bruno Estevan Siqueira Dario


    Full Text Available Este estudo teve como objetivo identificar as principais lesões no basquetebol e suas incidências. Participaram do estudo vinte jogadores de basquetebol do sexo masculino com idade variando entre 13 e 15 anos. O instrumento utilizado foi o questionário e seus resultados mostraram que, dos atletas participantes do estudo, todos relataram algum tipo de lesão. Foram identificadas 26 lesões, sendo 13 nos membros inferiores (50% e 13 nos membros superiores (50%. No joelho, as lesões mais frequentes foram a tendinite patelar - sete casos (53,85%. Nos membros superiores, destacaram-se as entorses nos dedos das mãos - cinco casos (38,46%. Com este estudo, percebemos a necessidade de se desenvolver um trabalho preventivo no intuito de diminuir a incidência dessas lesões.


    Celso Augusto de Matos


    Full Text Available O presente estudo teve como objetivo geral analisar os fatores associados ao superendividamento de consumidores de baixa renda. Foi realizado um estudo exploratório, de cunho qualitativo, por meio de entrevistas individuais com consumidores das classes D e E. Dentre os principais fatores associados ao acúmulo de dívidas pelos entrevistados, destacam-se as compras por impulso, o pagamento do valor mínimo das faturas do cartão de crédito, o uso de financiamentos e empréstimos para aquisição de bens ou até mesmo para pagar outra dívida e fatores imprevistos. O estudo termina com uma discussão teórica destes resultados e sugestões de pesquisa para estudos futuros.

  8. Laser system using ultra-short laser pulses

    Dantus, Marcos; Lozovoy, Vadim V.; Comstock, Matthew


    A laser system using ultrashort laser pulses is provided. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and binary pulse shaping (BPS). Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and a SHG crystal.

  9. Toxoplasmose em primatas neotropicais: estudo retrospectivo de sete casos

    Renata A. Casagrande


    Full Text Available A toxoplasmose é considerada uma doença parasitária fatal em primatas neotropicais. O objetivo deste trabalho foi descrever, através de um estudo retrospectivo, os casos de toxoplasmose em primatas neotropicais. No período de 1999-2009 foram realizados 86 exames anatomopatológicos em primatas e a toxoplasmose foi a enfermidade mais comum (7/86, relatando-se um caso em sagui-do-tufo-preto (Callithrix penicillata e seis em bugio-ruivo (Alouatta guariba. Dois animais foram encontrados mortos e cinco morreram em poucos dias. Os sinais clínicos mais frequentes foram apatia e anorexia (5/7, distensão abdominal (4/7 e febre (3/7. Na necropsia observou-se esplenomegalia (4/7, hemorragia do trato digestório, linfonodos e bexiga (4/7, pulmões avermelhados (3/7 e hepatomegalia (2/7. No exame histopatológico evidenciou-se hepatite (7/7, esplenite (3/7, miocardite (2/7, enterite (2/7, linfadenite (1/7 e sialite (1/7 necróticas e, pneumonia intersticial (4/7. Em fígado, pulmões, baço, coração, linfonodos e glândula salivar havia taquizoítos de Toxoplasma gondii que foram também detectados pelo exame de imuno-histoquímica anti-T. gondii em fígado, baço e pulmões (5/7. A toxoplasmose pode causar alta mortalidade em colônias de primatas neotropicais e representar mais uma ameaça à conversação dessas espécies em cativeiro. Sendo assim, medidas preventivas devem ser tomadas para evitar a contaminação desses animais.

  10. Atitude religiosa e sentido da vida: um estudo correlacional

    Thiago Antônio Avellar de Aquino

    Full Text Available A presente pesquisa abordou o sentido da vida (Viktor Frankl e a atitude religiosa. Para a logoterapia, a religiosidade não significa necessariamente a opção por uma crença religiosa, mas pode ser uma das possíveis maneiras de o homem encontrar sentido para a vida. O objetivo deste estudo foi investigar a relação entre o sentido de vida e a atitude religiosa de forma transversal e correlacional. A amostra foi composta por 300 sujeitos de ambos os sexos, 37% homens e 63% mulheres, com idade média de 42 anos. Os instrumentos utilizados foram o Teste Propósito de Vida (PIL-Test, de James C. Crumbauch e Leonard T. Maholick, e a Escala de Atitude Religiosa/Espiritualidade, de Aquino. Os resultados apontam correlações positivas entre a atitude religiosa e a realização existencial, a atitude religiosa e a idade, o desespero existencial e o vazio existencial e a realização existencial e a idade, havendo também correlações negativas entre a atitude religiosa e o desespero existencial, a atitude religiosa e o vazio existencial, o desespero existencial e a realização existencial e o vazio existencial e a realização existencial. Concluiu-se que a atitude religiosa é uma forma de encontro de sentido de vida bem como um elemento de prevenção do vazio existencial e do desespero existencial.

  11. Apoio Matricial: um estudo bibliográfico

    Alexandra Iglesias


    Full Text Available Este artigo constitui-se de um estudo de revisão bibliográfica a respeito do apoio matricial em saúde mental. Foi realizada uma busca nas bases de dados da Biblioteca Virtual da Saúde - Lilacs e SciELO - e do Google acadêmico, com as palavras-chave "apoio matricial em saúde mental" e/ou "matriciamento em saúde mental". Foram encontrados 14 artigos com as características desejadas, o que evidencia o número restrito de publicações sobre o tema. Os artigos foram analisados quanto a sua parte estrutural e metodológica, destacando a predominância absoluta do uso do método qualitativo e dos profissionais de saúde como população alvo das pesquisas. Em seguida, estes mesmos artigos foram analisados quanto a suas discussões teóricas. Ressalta-se, dentre outras questões, a importância do apoio matricial para potencialização das equipes da atenção básica no cuidado às pessoas em sofrimento psíquico. Contudo, ainda são muitas as confusões quanto à proposta do apoio matricial e as responsabilidades compartilhadas entre equipes de Referências e profissionais de saúde mental, o que apontam para a necessidade de capacitação destes profissionais, além de uma melhor articulação e organização da rede de cuidado em saúde mental.

  12. Frequency comb swept lasers.

    Tsai, Tsung-Han; Zhou, Chao; Adler, Desmond C; Fujimoto, James G


    We demonstrate a frequency comb (FC) swept laser and a frequency comb Fourier domain mode locked (FC-FDML) laser for applications in optical coherence tomography (OCT). The fiber-based FC swept lasers operate at a sweep rate of 1kHz and 120kHz, respectively over a 135nm tuning range centered at 1310nm with average output powers of 50mW. A 25GHz free spectral range frequency comb filter in the swept lasers causes the lasers to generate a series of well defined frequency steps. The narrow bandwidth (0.015nm) of the frequency comb filter enables a approximately -1.2dB sensitivity roll off over approximately 3mm range, compared to conventional swept source and FDML lasers which have -10dB and -5dB roll offs, respectively. Measurements at very long ranges are possible with minimal sensitivity loss, however reflections from outside the principal measurement range of 0-3mm appear aliased back into the principal range. In addition, the frequency comb output from the lasers are equally spaced in frequency (linear in k-space). The filtered laser output can be used to self-clock the OCT interference signal sampling, enabling direct fast Fourier transformation of the fringe signals, without the need for fringe recalibration procedures. The design and operation principles of FC swept lasers are discussed and designs for short cavity lasers for OCT and interferometric measurement applications are proposed.

  13. Photobiomodulation in laser surgery

    Liu, Timon Cheng-Yi; Rong, Dong-Liang; Huang, Jin; Deng, Xiao-Yuan; Liu, Song-Hao


    Laser surgery provides good exposure with clear operating fields and satisfactory preliminary functional results. In contrast to conventional excision, it was found that matrix metalloproteinases and the tissue inhibitors of metalloproteinases -1 mRNA expression is higher, myofibroblasts appeared and disappeared slower in laser excision wounds. It has been suggested that the better anatomical and functional results achieved following laser cordectomy may be explained by the fact that such procedures result in better, more rapid healing processes to recover vocal cord for early glottic tumors and better. In this paper, the role of photobiomodulation in laser surgery will be discussed by the cultured monolayer normal human skin fibroblast model of the photobiomodulation of marginal irradiation of high intensity laser beam, the photobiomodulation related to the irradiated tissue, the biological information model of photobiomodulation and the animal models of laser surgery. Although high intensity laser beam is so intense that it destroys the irradiated cells or tissue, its marginal irradiation intensity is so low that there is photobiomodulation on non-damage cells to modulate the regeneration of partly damaged tissue so that the surgery of laser of different parameters results in different post-surgical recovery. It was concluded that photobiomodulation might play an important role in the long-term effects of laser surgery, which might be used to design laser surgery.

  14. Laser treatment in gynecology

    de Riese, Cornelia


    This presentation is designed as a brief overview of laser use in gynecology, for non-medical researchers involved in development of new laser techniques. The literature of the past decade is reviewed. Differences in penetration, absorption, and suitable delivery media for the beams dictate clinical application. The use of CO2 laser in the treatment of uterine cervical intraepithelial lesions is well established and indications as well as techniques have not changed over 30 years. The Cochrane Systematic Review from 2000 suggests no obviously superior technique. CO2 laser ablation of the vagina is also established as a safe treatment modality for VAIN. CO2 laser permits treatment of lesions with excellent cosmetic and functional results. The treatment of heavy menstrual bleeding by destruction of the endometrial lining using various techniques has been the subject of a 2002 Cochran Database Review. Among the compared treatment modalities are newer and modified laser techniques. Conclusion by reviewers is that outcomes and complication profiles of newer techniques compare favorably with the gold standard of endometrial resection. The ELITT diode laser system is one of the new successful additions. CO2 laser is also the dominant laser type used with laparoscopy for ablation of endometriotic implants. Myoma coagulation or myolysis with Nd:Yag laser through the laparoscope or hysteroscope is a conservative treatment option. Even MRI guided percutaneous approaches have been described. No long-term data are available.

  15. Laser Stabilization with Laser Cooled Strontium

    Christensen, Bjarke Takashi Røjle

    the nonlinear effects from coupling of an optical cavity to laser cooled atoms having a narrow transition linewidth. Here, we have realized such a system where a thermal sample of laser cooled strontium-88 atoms are coupled to an optical cavity. The strontium-88 atoms were probed on the narrow 1S0-3P1 inter......The frequency stability of current state-of-the-art stabilized clock lasers are limited by thermal fluctuations of the ultra-stable optical reference cavities used for their frequency stabilization. In this work, we study the possibilities for surpassing this thermal limit by exploiting......-combination line at 689 nm in a strongly saturated regime. The dynamics of the atomic induced phase shift and absorption of the probe light were experimentally studied in details with the purpose of applications to laser stabilization. The atomic sample temperature was in the mK range which brought this system out...

  16. Lasers in medicine

    Peng, Qian; Juzeniene, Asta; Chen, Jiyao; Svaasand, Lars O.; Warloe, Trond; Giercksky, Karl-Erik; Moan, Johan


    It is hard to imagine that a narrow, one-way, coherent, moving, amplified beam of light fired by excited atoms is powerful enough to slice through steel. In 1917, Albert Einstein speculated that under certain conditions atoms could absorb light and be stimulated to shed their borrowed energy. Charles Townes coined the term laser (light amplification by stimulated emission of radiation) in 1951. Theodore Maiman investigated the glare of a flash lamp in a rod of synthetic ruby, creating the first human-made laser in 1960. The laser involves exciting atoms and passing them through a medium such as crystal, gas or liquid. As the cascade of photon energy sweeps through the medium, bouncing off mirrors, it is reflected back and forth, and gains energy to produce a high wattage beam of light. Although lasers are today used by a large variety of professions, one of the most meaningful applications of laser technology has been through its use in medicine. Being faster and less invasive with a high precision, lasers have penetrated into most medical disciplines during the last half century including dermatology, ophthalmology, dentistry, otolaryngology, gastroenterology, urology, gynaecology, cardiology, neurosurgery and orthopaedics. In many ways the laser has revolutionized the diagnosis and treatment of a disease. As a surgical tool the laser is capable of three basic functions. When focused on a point it can cauterize deeply as it cuts, reducing the surgical trauma caused by a knife. It can vaporize the surface of a tissue. Or, through optical fibres, it can permit a doctor to see inside the body. Lasers have also become an indispensable tool in biological applications from high-resolution microscopy to subcellular nanosurgery. Indeed, medical lasers are a prime example of how the movement of an idea can truly change the medical world. This review will survey various applications of lasers in medicine including four major categories: types of lasers, laser

  17. Dermatological laser treatment. Dermatologisk laserbehandling

    Moerk, N.J.; Austad, J. (Rikshospitalet, Oslo (Norway)); Helland, S. (Haukeland Sykehus, Bergen (Norway)); Thune, P. (Ullevaal Sykehus, Oslo (Norway)); Volden, G. (University and Regional Hospital, Trondheim (Norway)); Falk, E. (University and Regional Hospital, Tromsoe (Norway))


    The article reviews the different lasers used in dermatology. Special emphasis is placed on the treatment of naevus flammeus (''portwine stain'') where lasers are the treatment of choice. Argon laser and pulsed dye laser are the main lasers used in vascular skin diseases, and the article focuses on these two types. Copper-vapour laser, neodymium-YAG laser and CO{sub 2} laser are also presented. Information is provided about the availability of laser technology in the different health regions in Norway. 5 refs., 2 figs.

  18. High power lasers in manufacturing

    Chatwin, Chris R


    Lecture covers a brief history of lasers and the important beam parameters for manufacturing applications. It introduces the main laser types that are appropriate for manufacturing: carbon dioxide lasers, Nd YAG, Diode and fibre lasers, excimer lasers. It then looks at applications to different products and also micro-engineering

  19. Lasers in Dermatology and Medicine

    Nouri, Keyvan


    Laser technology is constantly evolving and progressing. The use of laser therapy is vastly expanding and for this reason a medical book of this magnitude is necessary. Lasers and Light Therapy includes an up-to-date comprehensive look at lasers and light therapy not only in the field of Cutaneous Laser Surgery, but in other medical specialties as well.

  20. Synthetic laser medium

    Stokowski, Stanley E.


    A laser medium is particularly useful in high average power solid state lasers. The laser medium includes a chormium dopant and preferably neodymium ions as codopant, and is primarily a gadolinium scandium gallium garnet, or an analog thereof. Divalent cations inhibit spiral morphology as large boules from which the laser medium is derived are grown, and a source of ions convertible between a trivalent state and a tetravalent state at a low ionization energy are in the laser medium to reduce an absorption coefficient at about one micron wavelength otherwise caused by the divalent cations. These divalent cations and convertible ions are dispersed in the laser medium. Preferred convertible ions are provided from titanium or cerium sources.

  1. Nuclear-pumped lasers

    Prelas, Mark


    This book focuses on Nuclear-Pumped Laser (NPL) technology and provides the reader with a fundamental understanding of NPLs, a review of research in the field, and exploration of large scale NPL system design and applications. Early chapters look at the fundamental properties of lasers, nuclear-pumping and nuclear reactions that may be used as drivers for nuclear-pumped lasers. The book goes on to explore the efficient transport of energy from the ionizing radiation to the laser medium and then the operational characteristics of existing nuclear-pumped lasers. Models based on Mathematica, explanations and a tutorial all assist the reader’s understanding of this technology. Later chapters consider the integration of the various systems involved in NPLs and the ways in which they can be used, including beyond the military agenda. As readers will discover, there are significant humanitarian applications for high energy/power lasers, such as deflecting asteroids, space propulsion, power transmission and mining....

  2. Lasers in periodontics

    Sugumari Elavarasu


    Full Text Available Laser is one of the most captivating technologies in dental practice since Theodore Maiman in 1960 invented the ruby laser. Lasers in dentistry have revolutionized several areas of treatment in the last three and a half decades of the 20 th century. Introduced as an alternative to mechanical cutting device, laser has now become an instrument of choice in many dental applications. Evidence suggests its use in initial periodontal therapy, surgery, and more recently, its utility in salvaging implant opens up a wide range of applications. More research with better designs are a necessity before lasers can become a part of dental armamentarium. This paper gives an insight to laser in periodontics.

  3. Laser induced nuclear reactions

    Ledingham, Ken; McCanny, Tom; Graham, Paul; Fang, Xiao; Singhal, Ravi; Magill, Joe; Creswell, Alan; Sanderson, David; Allott, Ric; Neely, David; Norreys, Peter; Santala, Marko; Zepf, Matthew; Watts, Ian; Clark, Eugene; Krushelnick, Karl; Tatarakis, Michael; Dangor, Bucker; Machecek, Antonin; Wark, Justin


    Dramatic improvements in laser technology since 1984 have revolutionised high power laser technology. Application of chirped-pulse amplification techniques has resulted in laser intensities in excess of 1019W/cm2. In the mid to late eighties, C. K. Rhodes and K. Boyer discussed the possibility of shining laser light of this intensity onto solid surfaces and to cause nuclear transitions. In particular, irradiation of a uranium target could induce electro- and photofission in the focal region of the laser. In this paper it is shown that μCi of 62Cu can be generated via the (γ,n) reaction by a laser with an intensity of about 1019Wcm-2.

  4. Power Laser Ablation Symposia

    Phipps, Claude


    Laser ablation describes the interaction of intense optical fields with matter, in which atoms are selectively driven off by thermal or nonthermal mechanisms. The field of laser ablation physics is advancing so rapidly that its principal results are seen only in specialized journals and conferences. This is the first book that combines the most recent results in this rapidly advancing field with authoritative treatment of laser ablation and its applications, including the physics of high-power laser-matter interaction. Many practical applications exist, ranging from inertial confinement fusion to propulsion of aerostats for pollution monitoring to laser ignition of hypersonic engines to laser cleaning nanoscale contaminants in high-volume computer hard drive manufacture to direct observation of the electronic or dissociative states in atoms and molecules, to studying the properties of materials during 200kbar shocks developed in 200fs. Selecting topics which are representative of such a broad field is difficu...

  5. Nanofabrication with Pulsed Lasers

    Kabashin AV


    Full Text Available Abstract An overview of pulsed laser-assisted methods for nanofabrication, which are currently developed in our Institute (LP3, is presented. The methods compass a variety of possibilities for material nanostructuring offered by laser–matter interactions and imply either the nanostructuring of the laser-illuminated surface itself, as in cases of direct laser ablation or laser plasma-assisted treatment of semiconductors to form light-absorbing and light-emitting nano-architectures, as well as periodic nanoarrays, or laser-assisted production of nanoclusters and their controlled growth in gaseous or liquid medium to form nanostructured films or colloidal nanoparticles. Nanomaterials synthesized by laser-assisted methods have a variety of unique properties, not reproducible by any other route, and are of importance for photovoltaics, optoelectronics, biological sensing, imaging and therapeutics.

  6. Lasers Fundamentals and Applications

    Thyagarajan, K


    Lasers: Fundamentals and Applications, serves as a vital textbook to accompany undergraduate and graduate courses on lasers and their applications. Ever since their invention in 1960, lasers have assumed tremendous importance in the fields of science, engineering and technology because of their diverse uses in basic research and countless technological applications. This book provides a coherent presentation of the basic physics behind the way lasers work, and presents some of their most important applications in vivid detail. After reading this book, students will understand how to apply the concepts found within to practical, tangible situations. This textbook includes worked-out examples and exercises to enhance understanding, and the preface shows lecturers how to most beneficially match the textbook with their course curricula. The book includes several recent Nobel Lectures, which will further expose students to the emerging applications and excitement of working with lasers. Students who study lasers, ...

  7. Laser materials production

    Gianinoni, I.; Musci, M.


    The characteristics and the perspectives of the new photochemical laser techniques for materials production will be briefly analysed and some recent experimental results both on large area deposition of thin films and on synthesis of powders will be reported. As an example of an IR laser process, the cw CO 2 laser-induced deposition of hydrogenated amorphous silicon will be described in some detail. The results of some UV experiments for semiconductor, metal and insulating film depositions will also be discussed. The features of the process for laser-driven synthesis of powders and the characteristics of the produced particles will be evidenced, and some of their technological applications will be outlined. The requirements of the laser sources suitable for this kind of applications are in general the same as in gas-phase laser chemistry, however it will be pointed out how some parameters are more significant for this specific use.

  8. Laser Cutting, Development Trends

    Olsen, Flemming Ove


    In this paper a short review of the development trends in laser cutting will be given.The technology, which is the fastest expanding industrial production technology will develop in both its core market segment: Flat bed cutting of sheet metal, as it will expand in heavy industry and in cutting o...... of 3-dimensional shapes.The CO2-laser will also in the near future be the dominating laser source in the market, although the new developments in ND-YAG-lasers opens for new possibilities for this laser type.......In this paper a short review of the development trends in laser cutting will be given.The technology, which is the fastest expanding industrial production technology will develop in both its core market segment: Flat bed cutting of sheet metal, as it will expand in heavy industry and in cutting...

  9. Principles of Lasers

    Svelto, Orazio


    This new Fifth Edition of Principles of Lasers incorporates corrections to the previous edition. The text’s essential mission remains the same: to provide a wide-ranging yet unified description of laser behavior, physics, technology, and current applications. Dr. Svelto emphasizes the physical rather than the mathematical aspects of lasers, and presents the subject in the simplest terms compatible with a correct physical understanding. Praise for earlier editions: "Professor Svelto is himself a longtime laser pioneer and his text shows the breadth of his broad acquaintance with all aspects of the field … Anyone mastering the contents of this book will be well prepared to understand advanced treatises and research papers in laser science and technology." (Arthur L. Schawlow, 1981 Nobel Laureate in Physics) "Already well established as a self-contained introduction to the physics and technology of lasers … Professor Svelto’s book, in this lucid translation by David Hanna, can be strongly recommended for...

  10. Single frequency semiconductor lasers

    Fang, Zujie; Chen, Gaoting; Qu, Ronghui


    This book systematically introduces the single frequency semiconductor laser, which is widely used in many vital advanced technologies, such as the laser cooling of atoms and atomic clock, high-precision measurements and spectroscopy, coherent optical communications, and advanced optical sensors. It presents both the fundamentals and characteristics of semiconductor lasers, including basic F-P structure and monolithic integrated structures; interprets laser noises and their measurements; and explains mechanisms and technologies relating to the main aspects of single frequency lasers, including external cavity lasers, frequency stabilization technologies, frequency sweeping, optical phase locked loops, and so on. It paints a clear, physical picture of related technologies and reviews new developments in the field as well. It will be a useful reference to graduate students, researchers, and engineers in the field.

  11. A gas laser system

    Sydzo, Y.; Norio, T.


    It is reported that an improved gas laser system with active medium circulation has been developed. The design of the gas laser is given in block diagram form, and its principle of operation is described in detail. The gaseous active medium flows through the inlet hole to the laser system, and is uniformly dispersed as it flows through the cylindrical diffuser. Thus, a near uniform distribution in the flow velocity of the gas flow in the laser discharge tube is achieved. The gas flow velocity along the edges of the discharge tube exceeds somewhat the flow velocity in the central section, which aids in generating and maintaining a stable and uniform pumping discharge. It is established experimentally that when using the proposed design, the parameters of the output emission from the gas laser are improved significantly. A relationship is given which demonstrates the near linear relationship between the pumping voltage and the output emission power from a gas laser.

  12. Laser/tissue interaction.

    Dederich, D N


    When laser light impinges on tissue, it can reflect, scatter, be absorbed, or transmit to the surrounding tissue. Absorption controls to a great degree the extent to which reflection, scattering and transmission occur, and wavelength is the primary determinant of absorption. The CO2 laser is consistently absorbed by most materials and tissues and the Nd-YAG laser wavelength is preferentially absorbed in pigmented tissues. The factors which determine the initial tissue effect include the laser wavelength, laser power, laser waveform, tissue optical properties, and tissue thermal properties. There are almost an infinite number of combinations of these factors possible, many of which would result in unacceptable damage to the tissues. This underscores the need to thoroughly test any particular combination of these factors on the conceptual, in-vitro, and in-vivo level before a treatment is offered.

  13. Tratamento de superfície de porcelanas dentárias pela irradiação com laser de CO2


    Este estudo teve como objetivo testar o laser de CO2 como um agente de tratamento de superfície de porcelanas dentárias. Material e Métodos: O estudo foi dividido em duas etapas: na primeira etapa, discos de porcelana (3,5 mm diam. x 2,0 mm espess.) das marcas VM7, VM9 e VM13 (VITA) foram sinterizados e tiveram uma de suas faces asperizadas por uma ponta diamantada 2134F para acabamento. Os espécimes foram então divididos em grupos de acordo com os seguintes tratamentos: nenhum (C), auto-glaz...

  14. Arduino based laser control

    Bernal Muñoz, Ferran


    ARDUINO is a vey usefull platform for prototypes. In this project ARDUINO will be used for controling a Semiconductor Tuneable Laser. [ANGLÈS] Diode laser for communications control based on an Arduino board. Temperature control implementation. Software and hardware protection for the laser implementation. [CASTELLÀ] Control de un láser de comunicaciones ópticas desde el ordenador utilizando una placa Arduino. Implementación de un control de temperatura y protección software y hardware ...

  15. Precision laser aiming system

    Ahrens, Brandon R.; Todd, Steven N.


    A precision laser aiming system comprises a disrupter tool, a reflector, and a laser fixture. The disrupter tool, the reflector and the laser fixture are configurable for iterative alignment and aiming toward an explosive device threat. The invention enables a disrupter to be quickly and accurately set up, aligned, and aimed in order to render safe or to disrupt a target from a standoff position.

  16. Laser cutting plastic materials

    Van Cleave, R.A.


    A 1000-watt CO/sub 2/ laser has been demonstrated as a reliable production machine tool for cutting of plastics, high strength reinforced composites, and other nonmetals. More than 40 different plastics have been laser cut, and the results are tabulated. Applications for laser cutting described include fiberglass-reinforced laminates, Kevlar/epoxy composites, fiberglass-reinforced phenolics, nylon/epoxy laminates, ceramics, and disposable tooling made from acrylic.

  17. Semiconductor laser. Halbleiterlaser

    Wuenstel, K.; Gohla, B.; Tegude, F.; Luz, G.; Hildebrand, O.


    A highly modulable semiconductor laser and a process for its manufacture are described. The semiconductor laser has a substrate, a stack of semiconductor layers and electrical contacts. To reduce the capacity, the width of the stack of semiconductor layers is reduced at the sides by anisotropic etching. The electrical contacts are situated on the same side of the substrate and are applied in the same stage of the process. The semiconductor laser is suitable for monolithic integration in other components.

  18. Laser In Veterinary Medicine

    Newman, Carlton; Jaggar, David H.


    Lasers have been used for some time now on animals for experimental purposes prior to their use in human medical and surgical fields. However the use of lasers in veterinary medicine and surgery per se is a recent development. We describe the application of high and low intensity laser technology in a general overview of the current uses, some limitations to its use and future needs for future inquiry and development.

  19. Laser precision microfabrication

    Sugioka, Koji; Pique, Alberto


    Miniaturization and high precision are rapidly becoming a requirement for many industrial processes and products. As a result, there is greater interest in the use of laser microfabrication technology to achieve these goals. This book composed of 16 chapters covers all the topics of laser precision processing from fundamental aspects to industrial applications to both inorganic and biological materials. It reviews the sate of the art of research and technological development in the area of laser processing.

  20. Arduino based laser control

    Bernal Muñoz, Ferran


    ARDUINO is a vey usefull platform for prototypes. In this project ARDUINO will be used for controling a Semiconductor Tuneable Laser. [ANGLÈS] Diode laser for communications control based on an Arduino board. Temperature control implementation. Software and hardware protection for the laser implementation. [CASTELLÀ] Control de un láser de comunicaciones ópticas desde el ordenador utilizando una placa Arduino. Implementación de un control de temperatura y protección software y hardware ...

  1. A gas laser design

    Syudzo, Y.; Nooya, Kh.


    A gas laser design that excludes direct contact between the gas medium and the atmosphere is proposed. The laser operates at a reduced gas pressure. After shutdown, a special system is used to increase the gas pressure inside the discharge chamber, which approaches atmospheric pressure. The laser employs an internal optical resonator. The electrical discharge which excites the gas medium originates from three electrodes located within the gas discharge tube.

  2. Lasers in Ophthalmology


    In recent years,lasers have entered every fieldof medicine and especially so in ophthalmol-ogy.The scientific basis of lasers in ophthal-mology is based on three mechanisms:1.Photothermal effectLasers:argon,krypton,dye and diodeA thermal effect is generated when laserenergy is absorbed by pigment leading to in-creased vibration and therefore heat content.A

  3. Introduction to laser technology

    Hitz, C Breck; Hecht, Jeff


    The only introductory text on the market today that explains the underlying physics and engineering applicable to all lasersAlthough lasers are becoming increasingly important in our high-tech environment, many of the technicians and engineers who install, operate, and maintain them have had little, if any, formal training in the field of electro-optics. This can result in less efficient usage of these important tools. Introduction to Laser Technology, Fourth Edition provides readers with a good understanding of what a laser is and what it can and cannot do. The book explains what types of las.

  4. Laser processing of materials

    J Dutta Majumdar; I Manna


    Light amplification by stimulated emission of radiation (laser) is a coherent and monochromatic beam of electromagnetic radiation that can propagate in a straight line with negligible divergence and occur in a wide range of wavelength, energy/power and beam-modes/configurations. As a result, lasers find wide applications in the mundane to the most sophisticated devices, in commercial to purely scientific purposes, and in life-saving as well as life-threatening causes. In the present contribution, we provide an overview of the application of lasers for material processing. The processes covered are broadly divided into four major categories; namely, laser-assisted forming, joining, machining and surface engineering. Apart from briefly introducing the fundamentals of these operations, we present an updated review of the relevant literature to highlight the recent advances and open questions. We begin our discussion with the general applications of lasers, fundamentals of laser-matter interaction and classification of laser material processing. A major part of the discussion focuses on laser surface engineering that has attracted a good deal of attention from the scientific community for its technological significance and scientific challenges. In this regard, a special mention is made about laser surface vitrification or amorphization that remains a very attractive but unaccomplished proposition.

  5. High power lasers

    Niku-Lari, A


    The use of lasers for the working and treatment of materials is becoming increasingly common in industry. However, certain laser applications, for example, in welding, cutting and drilling, are more widely exploited than others. Whilst the potential of lasers for the surface treatment of metals is well recognised, in practice, this particular application is a relative newcomer. The 24 papers in this volume present the latest research and engineering developments in the use of lasers for processes such as surface melting, surface alloying and cladding, and machining, as well as discussing th

  6. Laser welding in space

    Kaukler, W. F.; Workman, G. L.


    Autogenous welds in 304 stainless steel were performed by Nd-YAG laser heating in a simulated space environment. Simulation consists of welding on the NASA KC-135 aircraft to produce the microgravity and by containing the specimen in a vacuum chamber. Experimental results show that the microgravity welds are stronger, harder in the fusion zone, have deeper penetration and have a rougher surface rippling of the weld pool than one-g welds. To perform laser welding in space, a solar-pumped laser concept that significantly increases the laser conversion efficiency and makes welding viable despite the limited power availability of spacecraft is proposed.

  7. Trends in laser micromachining

    Gaebler, Frank; van Nunen, Joris; Held, Andrew


    Laser Micromachining is well established in industry. Depending on the application lasers with pulse length from μseconds to femtoseconds and wavelengths from 1064nm and its harmonics up to 5μm or 10.6μm are used. Ultrafast laser machining using pulses with pico or femtosecond duration pulses is gaining traction, as it offers very precise processing of materials with low thermal impact. Large-scale industrial ultrafast laser applications show that the market can be divided into various sub segments. One set of applications demand low power around 10W, compact footprint and are extremely sensitive to the laser price whilst still demanding 10ps or shorter laser pulses. A second set of applications are very power hungry and only become economically feasible for large scale deployments at power levels in the 100+W class. There is also a growing demand for applications requiring fs-laser pulses. In our presentation we would like to describe these sub segments by using selected applications from the automotive and electronics industry e.g. drilling of gas/diesel injection nozzles, dicing of LED substrates. We close the presentation with an outlook to micromachining applications e.g. glass cutting and foil processing with unique new CO lasers emitting 5μm laser wavelength.

  8. Lasers for industrial chemistry

    Jensen, R.J.; Robinson, C.P.


    Three categories for application of laser technology to applied-photochemistry research are set forth as (1) laser-based analytical techniques, (2) studies of chemical-reaction dynamics, and (3) chemical reactions with primary energy or control provided by lasers. Specific systems being developed and chemical processes being monitored by laser-techniques are described. Studies of laser diagnostics for coal gasification now involving measurement of coal gases downstream of the scrubber are discussed, and potential applications of laser techniques to measurements of the hot-gas regions of the gasifier itself are forecast. A technique developed for the monitoring of gaseous UF/sub 6/ in process streams by measurement of its fluorescence after irradiation with short uv pulses from tunable lasers indicates that this same technique might be applied to many other molecules by proper choice of exciting laser wavelength and monitor. Special laser techniques for monitoring the presence of harmfurst-calf heifer performance was not affected by the feeding of an ensiled cattle waste-peanut hulls mixture compared to a conventional feeding program.

  9. Gigashot Optical Laser Demonstrator

    Deri, R. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)


    The Gigashot Optical Laser Demonstrator (GOLD) project has demonstrated a novel optical amplifier for high energy pulsed lasers operating at high repetition rates. The amplifier stores enough pump energy to support >10 J of laser output, and employs conduction cooling for thermal management to avoid the need for expensive and bulky high-pressure helium subsystems. A prototype amplifier was fabricated, pumped with diode light at 885 nm, and characterized. Experimental results show that the amplifier provides sufficient small-signal gain and sufficiently low wavefront and birefringence impairments to prove useful in laser systems, at repetition rates up to 60 Hz.

  10. Laser aircraft. [using kerosene

    Hertzberg, A.; Sun, K.; Jones, W. S.


    The concept of a laser-powered aircraft is discussed. Laser flight would be completely compatible with existing airports and air-traffic control, with the airplane using kerosene only power, up to a cruising altitude of 9 km where the laser satellite would lock on and beam laser energy to it. Two major components make up the laser turbofan, a heat exchanger for converting laser radiation into thermal energy, and conventional turbomachinery. The laser power satellite would put out 42 Mw using a solar-powered thermal engine to generate electrical power for the closed-cycle supersonic electric discharge CO laser, whose radiators, heat exchangers, supersonic diffuser, and ducting will amount to 85% of the total subsystem mass. Relay satellites will be used to intercept the beam from the laser satellite, correct outgoing beam aberrations, and direct the beam to the next target. A 300-airplane fleet with transcontinental range is projected to save enough kerosene to equal the energy content of the entire system, including power and relay satellites, in one year.

  11. Physics of semiconductor lasers

    Mroziewicz, B; Nakwaski, W


    Written for readers who have some background in solid state physics but do not necessarily possess any knowledge of semiconductor lasers, this book provides a comprehensive and concise account of fundamental semiconductor laser physics, technology and properties. The principles of operation of these lasers are therefore discussed in detail with the interrelations between their design and optical, electrical and thermal properties. The relative merits of a large number of laser structures and their parameters are described to acquaint the reader with the various aspects of the semiconductor l

  12. Tunable Microfluidic Dye Laser

    Olsen, Brian Bilenberg; Helbo, Bjarne; Kutter, Jörg Peter


    We present a tunable microfluidic dye laser fabricated in SU-8. The tunability is enabled by integrating a microfluidic diffusion mixer with an existing microfluidic dye laser design by Helbo et al. By controlling the relative flows in the mixer between a dye solution and a solvent......, the concentration of dye in the laser cavity can be adjusted, allowing the wavelength to be tuned. Wavelength tuning controlled by the dye concentration was demonstrated with macroscopic dye lasers already in 1971, but this principle only becomes practically applicable by the use of microfluidic mixing...

  13. Principles of laser dynamics

    Khanin, YI


    This monograph summarizes major achievements in laser dynamics over the past three decades. The book begins with two introductory Chapters. Chapter 1 offers general considerations on quantum oscillators, formulates the requirements for the laser key elements and shows how these requirements are met in different laser systems. The second Chapter proposes the mathematical models used in semiclassical laser theory, discusses the approximations and simplifications in particular cases, and specifies the range of applicability of these models. In Chapters 3-5 attention is given primarily to the stea

  14. X-ray lasers

    Elton, Raymond C


    The first in its field, this book is both an introduction to x-ray lasers and a how-to guide for specialists. It provides new entrants and others interested in the field with a comprehensive overview and describes useful examples of analysis and experiments as background and guidance for researchers undertaking new laser designs. In one succinct volume, X-Ray Lasers collects the knowledge and experience gained in two decades of x-ray laser development and conveys the exciting challenges and possibilities still to come._Add on for longer version of blurb_M>The reader is first introduced

  15. Dental lasers and science.

    Zakariasen, K L; Dederich, D N


    We have attempted to accomplish two purposes in this article. First, we have presented the case that extensive scientific investigation must form the base of our profession, that it must be an ongoing, continuous process and that laser dentistry must be developed through extensive scientific inquiry--as all of our treatment modalities should be. Second, we have presented many examples of the science involved in the development of laser dentistry. Lasers do have far-reaching potential for application to dentistry. We, as a profession, must insist that such laser development is done properly, not foisted upon us based on anecdotal reports and incomplete research.

  16. Lighting with laser diodes

    Basu, Chandrajit; Meinhardt-Wollweber, Merve; Roth, Bernhard


    Contemporary white light-emitting diodes (LEDs) are much more efficient than compact fluorescent lamps and hence are rapidly capturing the market for general illumination. LEDs are also replacing halogen lamps or even newer xenon based lamps in automotive headlamps. Because laser diodes are inherently much brighter and often more efficient than corresponding LEDs, there is great research interest in developing laser diode based illumination systems. Operating at higher current densities and with smaller form factors, laser diodes may outperform LEDs in the future. This article reviews the possibilities and challenges in the integration of visible laser diodes in future illumination systems.

  17. Laser treatment of tattoos.

    Kilmer, S L


    All three Q-switched laser systems can effectively remove most tattoos with minimal scarring or other adverse sequelae. Despite advances in laser technology, all tattoos cannot be completely eliminated, and several wavelengths remain necessary to optimally treat multicolored tattoos. The major advantage of Q-switched laser irradiation to effect tattoo removal is the low risk of scarring associated with treatment. Limitations include the need for multiple treatment sessions, minimal to incomplete responses in some cases, and the possibility of pigmentary and textural changes. Research continues in an effort to perfect laser removal of tattoos.

  18. Estudos transcriptômicos no contexto da conectividade perturbada em esquizofrenia Transcriptome studies in the context of disturbed connectivity in schizophrenia

    Andrea Schmitt


    Full Text Available Esquizofrenia é uma severa doença neurobiológica com fatores genéticos e ambientais desempenhando um papel na fisiopatologia. Diversas regiões cerebrais têm sido implicadas no processo da doença e estão conectadas em complexos circuitos neuronais. Nos níveis molecular e celular, a conectividade afetada entre essas regiões, envolvendo mielinização disfuncional dos axônios neuronais, bem como as alterações no nível sináptico e metabolismo energético levando a distúrbios na plasticidade sináptica, são os maiores achados em estudos post-mortem. Estudos de microarranjos investigando a expressão gênica contribuíram para os achados de alterações em vias complexas em regiões cerebrais relevantes na esquizofrenia. Além disso, estudos utilizando microdissecção e captura a laser permitiram a investigação da expressão gênica em grupos específicos de neurônios. Entretanto, deve ser mantido em mente que em estudos post-mortem, confusos efeitos de medicação, qualidade de RNAm, bem como capacidade de mecanismos regenerativos neuroplásticos do cérebro em indivíduos com história de vida de esquizofrenia, podem influenciar o complexo padrão de alterações no nível molecular. Apesar dessas limitações, estudos transcriptômicos livres de hipóteses em tecido cerebral de pacientes esquizofrênicos oferecem uma possibilidade única para aprender mais sobre os mecanismos subjacentes, levando a novas ópticas da fisiopatologia da doença.Schizophrenia is a severe neurobiological disease with genetic and environmental factors playing a role in the pathophysiology. Several brain regions have been implicated in the disease process and are connected in complex neuronal circuits. On the cellular and molecular level, affected connectivity between these regions, involving dysfunctional myelination of neuronal axons, as well as alterations on the synaptic level and energy metabolism of neurons leading to disturbances in synaptic

  19. Estudos transcriptômicos no contexto da conectividade perturbada em esquizofrenia Transcriptome studies in the context of disturbed connectivity in schizophrenia

    Andrea Schmitt


    Full Text Available Esquizofrenia é uma severa doença neurobiológica com fatores genéticos e ambientais desempenhando um papel na fisiopatologia. Diversas regiões cerebrais têm sido implicadas no processo da doença e estão conectadas em complexos circuitos neuronais. Nos níveis molecular e celular, a conectividade afetada entre essas regiões, envolvendo mielinização disfuncional dos axônios neuronais, bem como as alterações no nível sináptico e metabolismo energético levando a distúrbios na plasticidade sináptica, são os maiores achados em estudos post-mortem. Estudos de microarranjos investigando a expressão gênica contribuíram para os achados de alterações em vias complexas em regiões cerebrais relevantes na esquizofrenia. Além disso, estudos utilizando microdissecção e captura a laser permitiram a investigação da expressão gênica em grupos específicos de neurônios. Entretanto, deve ser mantido em mente que em estudos post-mortem, confusos efeitos de medicação, qualidade de RNAm, bem como capacidade de mecanismos regenerativos neuroplásticos do cérebro em indivíduos com história de vida de esquizofrenia, podem influenciar o complexo padrão de alterações no nível molecular. Apesar dessas limitações, estudos transcriptômicos livres de hipóteses em tecido cerebral de pacientes esquizofrênicos oferecem uma possibilidade única para aprender mais sobre os mecanismos subjacentes, levando a novas ópticas da fisiopatologia da doença.Schizophrenia is a severe neurobiological disease with genetic and environmental factors playing a role in the pathophysiology. Several brain regions have been implicated in the disease process and are connected in complex neuronal circuits. On the cellular and molecular level, affected connectivity between these regions, involving dysfunctional myelination of neuronal axons, as well as alterations on the synaptic level and energy metabolism of neurons leading to disturbances in synaptic

  20. Millisecond laser machining of transparent materials assisted by nanosecond laser.

    Pan, Yunxiang; Zhang, Hongchao; Chen, Jun; Han, Bing; Shen, Zhonghua; Lu, Jian; Ni, Xiaowu


    A new form of double pulse composed of a nanosecond laser and a millisecond laser is proposed for laser machining transparent materials. To evaluate its advantages and disadvantages, experimental investigations are carried out and the corresponding results are compared with those of single millisecond laser. The mechanism is discussed from two aspects: material defects and effects of modifications induced by nanosecond laser on thermal stress field during millisecond laser irradiation. It is shown that the modifications of the sample generated by nanosecond laser improves the processing efficiency of subsequent millisecond laser, while limits the eventual size of modified region.

  1. Laser processing with specially designed laser beam

    Asratyan, A. A.; Bulychev, N. A.; Feofanov, I. N.; Kazaryan, M. A.; Krasovskii, V. I.; Lyabin, N. A.; Pogosyan, L. A.; Sachkov, V. I.; Zakharyan, R. A.


    The possibility of using laser systems to form beams with special spatial configurations has been studied. The laser systems applied had a self-conjugate cavity based on the elements of copper vapor lasers (LT-5Cu, LT-10Cu, LT-30Cu) with an average power of 5, 10, or 30 W. The active elements were pumped by current pulses of duration 80-100 ns. The duration of laser generation pulses was up to 25 ns. The generator unit included an unstable cavity, where one reflector was a special mirror with a reflecting coating. Various original optical schemes used were capable of exploring spatial configurations and energy characteristics of output laser beams in their interaction with micro- and nanoparticles fabricated from various materials. In these experiments, the beam dimensions of the obtained zones varied from 0.3 to 5 µm, which is comparable with the minimum permissible dimensions determined by the optical elements applied. This method is useful in transforming a large amount of information at the laser pulse repetition rate of 10-30 kHz. It was possible to realize the high-precision micromachining and microfabrication of microscale details by direct writing, cutting and drilling (with the cutting width and through-hole diameters ranging from 3 to 100 µm) and produce microscale, deep, intricate and narrow grooves on substrate surfaces of metals and nonmetal materials. This system is used for producing high-quality microscale details without moving the object under treatment. It can also be used for microcutting and microdrilling in a variety of metals such as molybdenum, copper and stainless steel, with a thickness of up to 300 µm, and in nonmetals such as silicon, sapphire and diamond with a thickness ranging from 10 µm to 1 mm with different thermal parameters and specially designed laser beam.

  2. Laser Program annual report 1987

    O' Neal, E.M.; Murphy, P.W.; Canada, J.A.; Kirvel, R.D.; Peck, T.; Price, M.E.; Prono, J.K.; Reid, S.G.; Wallerstein, L.; Wright, T.W. (eds.)


    This report discusses the following topics: target design and experiments; target materials development; laboratory x-ray lasers; laser science and technology; high-average-power solid state lasers; and ICF applications studies.

  3. O Instituto de Estudos Avançados da USP

    João Steiner


    Full Text Available COMENTA-SE a missão especial do Instituto de Estudos Avançados da USP a abrangente agenda de debates sobre problemas mundiais, nacionais e institucionais. A sobrevivência da biosfera do Planeta Terra está ameaçada pelas mudanças globais induzidas pela atividade humana. A par disto, as relações internacionais estão, hoje, marcadas pelo unilateralismo político e protecionismo comercial dos paises desenvolvidos. A inserção do Brasil neste mundo complexo traz no se bojo extraordinários desafios políticos e comerciais. No cenário nacional ressalta-se a Política de Ciência e Tecnologia com seu sucesso no que diz respeito à pós-graduação e produção científica a par do insucesso no uso do conhecimento e falta de inovação que ameaçam nossa competitividade internacional, desenvolvimento econômico e bem-estar social. Conclui-se chamando a atenção para a grande responsabilidade da USP e do IEA no debate dos problemas nacionais e internacionais.THE SPECIAL mission of the University of São Paulo's Institute of Advanced Studies is here outlined, with focus on a broad agenda involving global, national and institutional problems. The survival of the biosphere of the Planet Earth is endangered by global changes caused by human activities. In addition, the international environment is poisoned by the political unilateralism and commercial protectionism of the developed countries. The role of Brazil in this complex world holds extraordinary political and commercial challenges. Our national Science and Technology Policy has been successful in terms of postgraduate human resources and scientific production, but has lagged behind in applying knowledge and promoting technological innovation, thus endangering our international competitiveness, economical development and social welfare. The University of São Paulo and its Institute of Advanced Studies have great responsibilities in the discussion of national as well as international

  4. Eletrocardiografia computadorizada em cães: estudo comparativo

    Lídia S. Oliveira


    Full Text Available O método de eletrocardiografia computadorizada (ECG-C vem sendo crescentemente difundido na medicina veterinária, havendo atualmente diversas marcas e modelos de eletrocardiógrafos disponíveis no mercado. Diante da possibilidade de diferenças na sensibilidade e na reprodutibilidade das medidas obtidas nos traçados, o presente estudo teve como objetivo comparar os parâmetros eletrocardiográficos de cães, obtidos por dois sistemas. Foram avaliados dois diferentes softwares computadorizados, o Wincardio Micromed® (WIN e o modelo TEB ECGPC® (TEB. Quarenta e dois cães hígidos, de diferentes raças (Cocker Spaniel, Daschund, Labrador, Pinscher, Pit Bull Terrier Poodle, Schnauzer, Shit Tzu, Yorkshire e sem raça definida, machos e fêmeas e com idade entre 4 meses e 16 anos foram agrupados segundo o peso e examinados pelos dois sistemas. As medidas eletrocardiográficas dos diferentes traçados foram analisadas na derivação DII. Os resultados indicaram que o sistema TEB apresentou maior sensibilidade na obtenção das medidas de duração da onda P e do complexo QRS, enquanto o sistema WIN foi mais sensível para determinar as medidas de amplitude dos mesmos parâmetros. Os animais de maior porte (26-37kg apresentaram maior variância nas medidas de duração e amplitude de onda P e duração do complexo QRS em comparação aos cães de médio (14-25kg e pequeno (1-13kg porte. O achado de diferenças entre os sistemas testados deve ser levado em consideração ao se empregar os diversos equipamentos para diagnóstico por meio de ECG-C na rotina clínica, de modo a evitarem-se divergências na interpretação dos exames entre diferentes prestadores de serviços veterinários.

  5. Estudo in vitro da abrasividade de dentifrícios

    ANDRADE JUNIOR Antonio Carlos Canabarro


    Full Text Available O objetivo do presente estudo é avaliar a abrasividade de 15 dentifrícios, utilizando o aparelho Einlehner AT 1000. Uma solução contendo 50 g de cada creme dental mais 800 ml de água destilada era colocada no referido aparelho, que promovia 174.000 rotações da haste metálica, com um cilindro descartável de borracha, sobre uma tela de cobre pesada previamente (P1, por 100 minutos. Com o término da operação, a tela era lavada, seca e novamente pesada (P2. Através da equação: (P1-P2 ÷ 3,07 x 10-4 encontrava-se o número de gramas/metro2. Cada dentifrício foi testado 3 vezes e o valor final apresentado é a média dos 3 testes. Adicionalmente foram investigados o pH e o teor de sólidos das diferentes marcas. Os resultados mostraram que os dentifrícios possuem uma grande variação no grau de abrasão. As 3 marcas mais abrasivas foram: Close Up com flúor, Colgate Antitártaro e Oral B Dentes e Gengivas, as duas primeiras com dióxido de silício. As 3 marcas menos abrasivas foram: Colgate M.F.P. com cálcio, Gessy com flúor e Signal com flúor, todas com carbonato de cálcio. Os dentifrícios Close Up com flúor, Kolynos Ação Total e Oral B Dentes e Gengivas apresentaram um pH abaixo de 7, que pode indicar um possível efeito erosivo, associado à abrasão. Novas pesquisas são necessárias para comparar esses resultados com cremes dentais internacionais.

  6. Soft tissue application of lasers.

    Holt, Timothy L; Mann, Fred A


    Despite increasing numbers of veterinarians incorporating lasers into their clinical practices, little information has been published about laser clinical applications in soft tissue surgery. This article reviews soft tissue interaction, describes laser equipment and accessories commonly marketed to veterinarians, and discusses clinical applications of the carbon dioxide laser in a systems-based approach. A table of recommended laser tips and settings based on the authors' experiences using a carbon dioxide laser (AccuVet Novapulse LX-20SP, Bothell, WA) is provided.

  7. Comparação das técnicas de turbinectomia com laser de CO2 e laser a diodo

    Cintra Pedro Paulo Vivacqua da Cunha


    Full Text Available Avaliação das técnicas de turbinectomia com laser de CO2 e da redução volumétrica das conchas nasais inferiores de maneira intersticial com o laser de diodo, em pacientes com hipertrofia do parênquima nasal. FORMA DE ESTUDO: Coorte Longitudinal. MATERIAL E MÉTODO: Foram avaliados 60 pacientes submetidos a estes procedimentos com um período de seguimento de 6 meses de acordo com protocolo onde foram avaliados os parâmetros de sangramento, dor e avaliação subjetiva da obstrução nasal pré e pós-operatória. RESULTADOS: As técnicas demonstraram um baixo índice de sangramento não tendo sido necessário o tampão nasal em nenhum dos casos e alto grau de satisfação dos pacientes no quesito obstrução nasal quando comparados os valores iniciais com os resultados aos seis meses. CONCLUSÃO: Os procedimentos nas conchas nasais devem visar a melhora do quadro obstrutivo, e satisfação do paciente com pouco desconforto tanto intra como pós-operatório. As técnicas de redução volumétrica com o laser de diodo e de CO2 mostram-se no presente estudo eficazes em 6 meses.

  8. Contribuição ao estudo da Tripanosomiase Americana

    Bichat de Almeida Rodrigues


    Full Text Available 1 Em trabalho sistematizado, foi estudada pela primeira vez a epidemiologia da doença de Chagas, em um trecho da região do estuário do Amazonas, cujas condições ecológicas diferem das encontradas em outras zonas onde teem sido feitas pesquisas semelhantes. 2 No local escolhido para estudo – Aura – uma localidade distante cerca de 10 km. de Belém, (Pará, não foi encontrada nenhuma infecção humana pelo S. cruzi, quer pelo exame de sangue, quer pelo xenodiagnóstico, ambos feitos em todos os habitantes (117 indivíduos. Não foi encontrada também sintomatologia atribuível à doença. 3 Em 6 xenodiagnósticos feitos em animais domésticos (5 cães e 1 gato, foi encontrado um cão infectado. Este animal pertencia á casa onde foi verificada maior infestação por Triatomídeos, com índice de infecção elevado. Pelas razões expostas no texto, porem, foi sugerida a hipótese do mesmo se ter infectado pela ingestão de vísceras de animais silvestres contaminados. 4 De 115 animais silvestres, cujo sangue foi examinado em gota espessa, 9 mostraram-se parasitados por Schizotrypanum (7,8%. Em 47 verificações pelo xenodiagnóstico, 15 animais silvestres (11 mucuras, 3 tamanduás e 1 tatú se apresentaram positivos (32,6% . O tamanduá (T. tetradactylus foi pela primeira vez assinalado como depositário natural do Schizotrypanum. 5 Como resultado de buscas feitas durante 11 meses, sendo cada domicílio inspecionado pelo menos de 15 em 15 dias, foram encontrados Triatomídeos em 7 das 36 casas existentes no povoado. Todos os 39 exemplares capturados eram adultos; a procura exaustiva não revelou a existência de formas jovens no interior das habitações. Na ordem de freqüência, as espécies encontradas foram as seguintes: P. geniculatus (29 exemplares, dos quais 7 infectados; R. pictipes ( 9 exemplares, dos quais 2 infectados; E. mucronatus ( 1 exemplar, não infectado . A grande maioria dos insetos foi capturada na segunda metade do

  9. Estudos sôbre índice de siclemia

    Ernani Martins da Silva


    Full Text Available O índice de sinclêmicos encontrado foi de 10%, examinando-se uma amostra heterógenea de 1130 indivíduos de grupo étnico negróide e mestiços desta etnia. Foi negativa a pesquisa em 120 indivíduos caucasóides e 30 mongolóides. O "índice familiar de siclêmicos" - a percentagem desses indivíduos em um grupo de famílias - fornece um resultado mais proximo do verdadeiro número de siclêmicos em uma amostra de população. O método clássico fornece um número inferior ao existente na amostra estudada. A aplicação do teste de siclemia em Jurisprudência, Antropologia e Etnografia, poderá contribuir, na qualidade de método auxiliar, no estudo de vários problemas. São indicados como métodos de escolha: o de Emmel e o de maceração de tecidos conservados em solução de formol ou alcool. Êste último permite estudos retrospectivos. A estase circulatória parece não ser fator suficiente para a passagem da condição de siclêmico para anemico. O parasitismo da hemátia pelo Plasmodium vivax não impede o fenômeno da siclisação. Infecção por plasmodídeos (P. falciparum e P. vivax não é fator suficiente para desencadear a doença. A importância da descoberta de Emmel (descoberta do fenômeno da siclisação reside no conhecimento em doença heredofamiliar de fato novo de máxima significação: a possibilidade de identificar os indivíduos ainda na fase de latência, ou seja, no período que medeia entre o nascimento e a instalação dos primeiros sintomas da doença. A relação entre casos de anemia falciforme ocorridos em gerações por vêzes muito afastadas (fenômeno denominado "skipping" - salto - pelos autores de lingua inglêsa é mantida através dos siclêmicos. Êsses indivíduos podem ser comparados aos portadores de germe no sentido empregado na profilaxia das doenças infectuosas. Exames periódicos dos siclêmicos poderiam contribuir para esclarecimento da patogenia e forneceriam dados úteis para a

  10. Laser Stabilization with Laser Cooled Strontium

    Christensen, Bjarke Takashi Røjle

    The frequency stability of current state-of-the-art stabilized clock lasers are limited by thermal fluctuations of the ultra-stable optical reference cavities used for their frequency stabilization. In this work, we study the possibilities for surpassing this thermal limit by exploiting the nonli......The frequency stability of current state-of-the-art stabilized clock lasers are limited by thermal fluctuations of the ultra-stable optical reference cavities used for their frequency stabilization. In this work, we study the possibilities for surpassing this thermal limit by exploiting...... the nonlinear effects from coupling of an optical cavity to laser cooled atoms having a narrow transition linewidth. Here, we have realized such a system where a thermal sample of laser cooled strontium-88 atoms are coupled to an optical cavity. The strontium-88 atoms were probed on the narrow 1S0-3P1 inter......-combination line at 689 nm in a strongly saturated regime. The dynamics of the atomic induced phase shift and absorption of the probe light were experimentally studied in details with the purpose of applications to laser stabilization. The atomic sample temperature was in the mK range which brought this system out...

  11. High-power pulsed lasers

    Holzrichter, J.F.


    The ideas that led to the successful construction and operation of large multibeam fusion lasers at the Lawrence Livermore Laboratory are reviewed. These lasers are based on the use of Nd:glass laser materials. However, most of the concepts are applicable to any laser being designed for fusion experimentation. This report is a summary of lectures given by the author at the 20th Scottish University Summer School in Physics, on Laser Plasma Interaction. This report includes basic concepts of the laser plasma system, a discussion of lasers that are useful for short-pulse, high-power operation, laser design constraints, optical diagnostics, and system organization.

  12. Laser safety tools and training

    Barat, Ken


    Lasers perform many unique functions in a plethora of applications, but there are many inherent risks with this continually burgeoning technology. Laser Safety: Tools and Training presents simple, effective ways for users in a variety of facilities to evaluate the hazards of any laser procedure and ensure they are following documented laser safety standards.Designed for use as either a stand-alone volume or a supplement to Laser Safety Management, this text includes fundamental laser and laser safety information and critical laser use information rarely found in a single source. The first lase

  13. Comprometimento organizacional e características de personalidade : um estudo de suas relações

    Faiad, Stela Gomes


    Os estudos sobre o Comprometimento Organizacional são caracterizados pela busca dos antecedentes, consequentes e elementos correlacionados ao Comprometimento no trabalho. O avanço nas pesquisas tem demonstrado a importância dos estudos que investigam a influência das características pessoais sobre o Comprometimento Organizacional dos funcionários. Inserido nesse contexto, os estudos que relacionam a Personalidade, mais especificamente o modelo dos cinco grandes fatores de Personalidade, com d...

  14. Learning about Lasers

    Roberts, Larry


    The word laser is an acronym. It stands for Light Amplification by Stimulated Emission of Radiation. Lasers, invented in 1958, are used to cut and fuse materials, accurately survey long distances, communicate across fiber-optic phone lines, produce 3D pictures, make special effects, help navigation, and read bar codes for cash registers. A laser…

  15. Laser Hazards Bibliography


    Copeland , H. P., and DeRose, L. B., Evaluation and control of hazards in laser light shows, Hlth Physics 31(2): 189-190 (1976). 58. Blaney, L., Perspectives...School of Aerospace Med, Brooks AF Base, TX, 51: 304 (1974). 434. Weston , B. A., Laser Systems-Code of Practice, Ministry of Technology Safety Services

  16. Fine welding with lasers.

    MacLellan, D


    The need for micro joining metallic alloys for surgical instruments, implants and advanced medical devices is driving a rapid increase in the implementation of laser welding technology in research, development and volume production. This article discusses the advantages of this welding method and the types of lasers used in the process.

  17. Exciton laser rate equations

    Garkavenko A. S.


    Full Text Available The rate equations of the exciton laser in the system of interacting excitons have been obtained and the inverted population conditions and generation have been derived. The possibility of creating radically new gamma-ray laser has been shown.

  18. Levitated droplet dye laser

    Azzouz, H.; Alkafadiji, L.; Balslev, Søren


    a high quality optical resonator. Our 750 nL lasing droplets consist of Rhodamine 6G dissolved in ethylene glycol, at a concentration of 0.02 M. The droplets are optically pumped at 532 nm light from a pulsed, frequency doubled Nd:YAG laser, and the dye laser emission is analyzed by a fixed grating...

  19. Laser hair removal pearls.

    Tierney, Emily P; Goldberg, David J


    A number of lasers and light devices are now available for the treatment of unwanted hair. The goal of laser hair removal is to damage stem cells in the bulge of the follicle through the targeting of melanin, the endogenous chromophore for laser and light devices utilized to remove hair. The competing chromophores in the skin and hair, oxyhemoglobin and water, have a decreased absorption between 690 nm and 1000 nm, thus making this an ideal range for laser and light sources. Pearls of laser hair removal are presented in this review, focusing on four areas of recent development: 1 treatment of blond, white and gray hair; 2 paradoxical hypertrichosis; 3 laser hair removal in children; and 4 comparison of lasers and IPL. Laser and light-based technologies to remove hair represents one of the most exciting areas where discoveries by dermatologists have led to novel treatment approaches. It is likely that in the next decade, continued advancements in this field will bring us closer to the development of a more permanent and painless form of hair removal.

  20. Laser biostimulation in pediatrics

    Utz, Irina A.; Lagutina, L. E.; Tuchin, Valery V.


    In the present paper the method and apparatus for percutaneous laser irradiation of blood (PLIB) in vessels (veins) are described. Results of clinical investigations of biostimulating effects under PLIB by red laser light (633 nm) in Cubiti and Saphena Magna veins are presented.