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YAG Laser Irradiation (yag + laser_irradiation)
Selected AbstractsEffect of Er:YAG laser and EDTAC on the adhesiveness to dentine of different sealers containing calcium hydroxideINTERNATIONAL ENDODONTIC JOURNAL, Issue 7 2003F. Picoli Abstract Aim, To evaluate the effect of 15% EDTAC solution and Er:YAG laser irradiation on the adhesiveness to dentine of root canal sealers containing calcium hydroxide. Methodology, The crowns of 60 maxillary human molars were ground until dentine was exposed. The teeth were divided into three groups of 20 teeth: group I, the dentine surface received no treatment; group II, 15% EDTAC solution was applied to the dentine; group III, the dentine received Er:YAG laser application (11 mm focal distance with perpendicular incidence to dentine surface; 4 Hz frequency; 200 mJ energy; 2.25 W potency; 62 J total energy; 1 min application time). Aluminium cylinders filled with the sealers, Sealer 26, Apexit, Sealapex and CRCS, were then applied to the treated surfaces. Adhesiveness was measured with a universal testing machine, with traction results given in MegaPascals (MPa). These results were submitted to anova tests. Results, Statistical analysis showed significant differences (P < 0.01) amongst adhesiveness values of the sealers and treatments tested. Thus, sealers could be ranked in decreasing adhesiveness values: Sealer 26, CRCS, Apexit, Sealapex. Er:YAG laser irradiation and EDTAC solution application increased adhesiveness values only for Sealer 26 and Apexit. Laser irradiation was superior to EDTAC application only for Sealer 26 adhesiveness values. Conclusions, Er:YAG laser is as efficient as EDTAC solution in increasing adhesiveness of root canal sealers containing calcium hydroxide to human dentine. [source] Adhesion of a self-etching system to dental substrate prepared by Er:YAG laser or air abrasionJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2008Wanessa C. Souza-Zaroni Abstract The purpose of this study was to assess the microtensile bond strength of a self-etching adhesive system to enamel and dentin prepared by Er:YAG laser irradiation or air abrasion, as well as to evaluate the adhesive interfaces by scanning electron microscopy (SEM). For microtensile bond strength test, 80 third molars were randomly assigned to five groups: Group I, carbide bur, control (CB); II, air abrasion with standard tip (ST); III, air abrasion with supersonic tip (SP); IV, Er:YAG laser 250 mJ/4 Hz (L250); V, Er:YAG laser 300 mJ/4 Hz (L300). Each group was divided into two subgroups (n = 8) (enamel, E and dentin, D). E and D surfaces were treated with the self-etching system Adper Prompt L-Pop and composite buildups were done with Filtek Z-250. Sticks with a cross-sectional area of 0.8 mm2 (±0.2 mm2) were obtained and the bond strength tests were performed. Data were submitted to ANOVA and Tukey's test. For morphological analysis, disks of 30 third molars were restored, sectioned and prepared for SEM. Dentin presented the highest values of adhesion, differing from enamel. Laser and air-abrasion preparations were similar to enamel. Dentin air-abrasion with standard tip group showed higher bond strength results than Er:YAG-laser groups, however, air-abrasion and Er:YAG laser groups were similar to control group. SEM micrographs revealed that, for both enamel and dentin, the air-abrasion and laser preparations presented irregular adhesive interfaces, different from the ones prepared by rotary instrument. It was concluded that cavity preparations accomplished by both Er:YAG laser energies and air abrasion tips did not positively influence the adhesion to enamel and dentin. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008 [source] Root surface roughness following Er:YAG laser irradiation at different radiation energies and working tip angulationsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 7 2002Matthias Folwaczny Abstract Objectives: The determination of roughness of root surfaces following treatment with 2.94 µm Er:YAG laser radiation at different radiation energies and working tip angulations. Materials and methods: The study sample comprised 85 extracted human molars, premolars, canines and incisors (n = 85). The source of laser radiation was an Er:YAG laser device (KAVO-Key II, System Aesculap Meditec) emitting pulsed infrared radiation at a wavelength of 2.94 µm, with a pulse duration of 250 µs, and a pulse repetition rate of 10 pps. The samples were randomly divided into three experimental units, for treatment with a constant amount of 380 laser pulses at a radiation energy of 60 mJ, 100 mJ, and 180 mJ. Each experimental unit was divided into five subgroups of five samples, which were irradiated at a working tip angulations of 15°, 30°, 45°, 60°, and 90°. Five samples were treated mechanically using curettes. Five samples were left untreated as control. The mean (Ra) and maximum (Rmax) surface roughness of each sample was measured using a profilometer. The statistical analysis was undertaken using anova and Scheffé-test at a level of significance of 5% (p < 0.05). Results: Er:YAG laser radiation led to an Ra which ranged from 0.52 µm (± 0.10) to 0.81 µm (± 0.26) and to an Rmax between 3.4 µm (± 0.48) and 9.26 µm (± 3.08). The Ra and Rmax for samples treated with curettes was 0.51 µm (± 0.11) and 5.08 µm (± 4.98), respectively. That for the untreated control samples were 0.53 µm (± 0.15) and 7.07 µm (± 5.48), respectively. Conclusions: The mean and maximum surface roughness of root surfaces following irradiation with Er:YAG laser was not significantly different to that obtained on samples treated with conventional hand instruments or left untreated. Furthermore, the surface roughness does not depend on the radiation energy and the angulation of the working tip. [source] Morphology, chemical structure and diffusion processes of root surface after Er:YAG and Nd:YAG laser irradiationJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 6 2001B. Ga Abstract Objectives: The aim of this in vitro study was to evaluate the effects of Er:YAG and Nd:YAG lasers on morphology, chemical structure and diffusion processes of the root surface. Material and methods: 60 root samples were irradiated for 1 min each either with 60 mJ/p, 80mJ/p and 100mJ/p using Er:YAG laser or with 0.5W, 1.0W and 1.5W using Nd:YAG laser. Scanning electron microscopy (SEM) was used to determine the morphology, infrared (IR) spectroscopy to assess the alterations in chemical structure and one dimensional electron paramagnetic resonance imaging (1-D EPRI) was used to estimate the diffusion coefficients in dental root samples. Results: Er:YAG laser treatment resulted in deep crater formation with exposed dentin. Morphological alterations of root surface after Nd:YAG laser irradiation included cracks, crater formation, meltdown of the root mineral and resolidified porous globules formation. Er:YAG laser failed to alter the intensity of Amide peaks I, II or III. In contrast, treatment with Nd:YAG laser, using the highest power setting of 1.5W, reduced the intensity of Amide peak II and III in comparison to the control. The diffusion coefficients were increased significantly in all Er:YAG and Nd:YAG treated root samples. Conclusion: This study demonstrated that Er:YAG laser influences only on morphology and diffusion processes of root surfaces, while Nd:YAG laser also alters the chemical structure of root proteins. Zusammenfassung Ziele: Das Ziel dieser in vitro Studie war es, die Wirkung von Er:YAG- und Nd:YAG-Laser auf die Morphologie, chemische Struktur und die Diffusionsprozesse zu evaluieren. Material und Methoden: 60 Proben von Wurzeln wurden für eine Minute entweder mit einem Er:YAG-Laser und 60 mJ/p, 80 mJ/p und 100 mJ/p oder einem Nd:YAGLaser und 0.5 W, 1.0 W und 1.5 W bestrahlt. Die Rasterelektronenmikroskopie (REM) wurde verwendet um die Morphologie zu bestimmen, Infrarotspektroskopie (IR) zur Messung der Veränderung in der chemischen Struktur und die eindimensionale paramagnetische Elektronenresonanz-Bildgebung (1-D EPRI) wurde verwendet um die Diffusions-Koeffizienten in den dentalen Wurzelproben abzuschätzen. Ergebnisse: Die Behandlung mit dem Er: YAG-Laser resultierte in der Ausbildung tiefer Krater mit exponiertem Dentin. Die morphologischen Veränderungen der Wurzeloberfläche nach Bestrahlung mit dem Nd: YAG-Laser waren Brüche, Kraterbildung, Aufschmelzen des Wurzelminerals und Bildung wiederverfestigter poröser Globuli. Mit dem Er:YAG-Laser gelang es nicht die Intensität der Amid-peaks I, II oder III zu verändern. Im Gegensatz dazu reduzierte die Behandlung mit dem Nd:YAG-Laser im Vergleich mit der Kontrolle bei der höchsten Leistungseinstellung von 1.5 W die Intensität der Amid-Peaks II und III. In allen mit Er: YAG und Nd:YAG behandelten Wurzelproben waren die Wurzeldiffusionskoeffizienten signifikant erhöht. Schlussfolgerung: Diese Studie demonstrierte, dass der Er:YAG-Laser nur die Morphologie und die Diffusionsprozesse der Wurzeloberfläche beeinflusst, während der Nd: YAG-Laser auch die chemische Struktur der Wurzelproteine verändert. Résumé Morphologie, structure chimique et processus de diffusion de surfaces radiculaires après irradiation au lasers Er:YAG et Nd:YAG But: Le but de cette étude in vitro était d'évaluer les effets des lasers Er:YAG et Nd:YAG sur la morphologie, la structure chimique et les processus de diffusion des surfaces radiculaires. Matériaux et méthodes: 60 échantillons de racines furent irradiés pendant 1 min chacun par 60 mJ/p, 80 mJ/p et 100 mJ/p avec le laser Er:YAG ou par 0.5 W, 1.0 W et 1.5 W avec le laser Nd:YAG. La microscopie électronique à balayage (SEM) a été utilisée pour déterminer la morphologie, la spectroscopie infra rouge pour mettre en évidence les altérations de la structure chimique et l'imagerie en une dimension par résonnance magnétique électronique (1-DEPRI) fut utilisée pour estimer les coefficients de diffusion dans les échantillons de racines dentaires. Résultats: Le traitement au laser Er:YAG entrainait la formation de cratères profonds avec de la detine exposée. Les altérations morphologiques de la surface radiculaire après irradiation au laser Nd:YAG prenaient la forme de félures, de cratères, fusion du minéral radiculaire et formation de globules poreux resolidifiés. Le laser Er:YAG n'arrivait pas à altérer l'intensité des pics Amide I, II our III. Au contraire, le traitement au laser Nd:YAG, en utilisant la plus haute puissance de 1.5 W, réduisait l'intensité des pics Amide II et III, par rapport au contrôle. Les coefficients de diffusion étaient significativement augmentés pour toutes les racines traitées par les lasers Er:YAG et Nd:YAG. Conclusions: Cette étude démontre que le laser Er:YAG a une influence sur seulement la morphologie et les processus de diffusion des surfaces radiculaires alors que le laser Nd:YAG modifie également la structure chinique des protéines radiculaires. [source] Dentin strain induced by laser irradiationAUSTRALIAN ENDODONTIC JOURNAL, Issue 2 2010Satoshi Watanabe dds Abstract The purpose of this study was to investigate the strain and temperature change in dentin induced by laser irradiation of human root canals with or without water cooling. Twenty-eight palatal roots of extracted human maxillary first molars were used. The strain in dentin was measured using strain gauges fixed on the apical third of the buccal root surface. The temperature change of the root dentin was monitored using thermocouples embedded into dentin near the apex. The root canal was irradiated with Er:YAG or Nd:YAG laser at an output of 1 W (100 mJ, 10 pps) for 5 s. The tip of the irradiation fibre was located 2.0 mm from the root apex. With water cooling, the mean maximum strain induced by Er:YAG laser was significantly lower than that by Nd:YAG laser (P < 0.05). However, without water cooling, no significant difference between the two lasers (P > 0.05) was found. The results suggest that the strain induced by Er:YAG laser irradiation in dentin with water cooling may be minimal, but there still might be a risk of root micro-fracture if cooling is not sufficient. [source] | ||||||||||