• Title, Summary, Keyword: Argon 레이저

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The Effect of Argon Laser on Periodontal Disease (치주질환에 대한 Argon 레이저의 효과)

  • Ahn, Hyung-Joon;Ryu, Ji-Won;Kim, Jae-Hong;Kim, Chong-Youl
    • Journal of Oral Medicine and Pain
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    • v.30 no.2
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    • pp.277-285
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    • 2005
  • The purpose of this study was to evaluate photothermal effect of laser, which eliminates and reduces bacteria causing periodontal disease, on treatment of periodontal disease. This study included subjects with moderate periodontitis who visited the Department of Oral Medicine, College of dentistry, Yonsei University. The subjects were divided into experimental group, where Argon laser treatment was used, and control group, where conventional subgingival curettage was used. Gingival fluids from each subject were collected prior and after 1 week of the treatment, and changes in number of bacterial colonies cultured from aerobic as well as anaerobic bacteria responsible for the periodontal disease, and changes in clinical indices related to the periodontal disease, such as plaque index, gingival index, sulcus bleeding index, were analysed. As a result, the number of bacterial colonies of aerobic and anaerobic bacteria reduced after 1 week of the treatment in both groups, especially the bacterial colonies of anaerobic bacteria which showed statistically significant reduction(p<0.1). However, there was no significant difference between the experimental group and the control group. Clinical indices including plaque index, gingival index, sulcus bleeding index were reduced after 1 week of the treatment in both groups. In the experimental group, gingival index(p<0.1) and sulcus bleeding index(p<0.01) showed significant reduction, and, in the control group, sulcus bleeding index(p<0.01) showed significant reduction. However, there were no significant differences in each indices between the two groups. The above results suggest that Argon laser could be used as a substitute of conventional subgingival curettage, or in combination with subgingival curettage which would increase the effect of the treatment. Although the possibility of clinical application of Argon laser was observed in this study, more randomized-controlled research, including acquirement of sufficient samples as well as long-termed follow up, would be necessary before clinically effective application of Argon laser.

Fabrication of waveguide using UV Ar-ion laser direct writing (Laser Direct Writing 방법을 이용한 광도파로 제작)

  • Kang H. S.;Suh J.;Lee J. H.;Kim J. O.
    • Laser Solutions
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    • v.8 no.1
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    • pp.9-18
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    • 2005
  • The laser direct writing method using a UV Argon-ion laser is studied for fabrication of waveguide. The laser direct writing system is constructed with a vision camera, a xy-stage, a motion controller and the delivery components of a laser beam. The UV Argon-ion laser has wavelength range of $333.6\~363.8$ nm. A photo-active UV curable polymer for a planar light-wave circuit(PLC) of single mode is used. This polymer is irradiated by Argon-ion laser and developed by a solvent after a post-baking. The optimum laser direct writing condition is obtained experimentally by changing various process parameters such as laser power, writing speed and focal length. The propagation and coupling loss of a optical waveguide was measured as 1dB/cm and 0.6dB/cm, respectively. Also, the minimum width of waveguide of $100{\mu}m$(ZPLW-207) is obtained. Finally, the waveguides of line, bend and branch type are successfully fabricated.

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DETECTION OF OCCLUSAL CARIES USING LASER FLUORESCENCE (레이저 형광법의 교합면 우식증 탐지 효과)

  • Kim, Chang-Gi;Lee, Chang-Seop;Lee, Sang-Ho
    • JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY
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    • v.29 no.4
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    • pp.600-606
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    • 2002
  • The purpose of this study was to evaluate the diagnostic validity of an incipient occlusal caries using argon laser fluorescence. Extracted human premolars and molars with enamel carious lesion of occlusal surface were assessed using visual examination, visual examination with probing, argon laser fluorescence and histologic depth of carious lesion. The results in each of all the three detection methods were compared to the assessment of histologic depth of carious lesion using polarized microscope. The results from the present study can be summarized as follows; 1. There was highly correlation between the histologic depth of occlusal caries and all three detection methods(P<0.01). 2. The reproducibility(kappa value) of the visual examination, visual examination with probing and argon laser fluorescence between the histologic depth of occlusal caries was 0.189, 0.128, 0.472. The highest correlation was seen between detection of occlusal caries by argon laser fluorescence and histologic scores by polarized microscope. The results from this study indicated that argon laser fluorescence considered to be accurate and reliable method in detecting occlusal caries.

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Atomic Emission Characteristics of Laser-Induced Plasma for INVAR in an Argon and a Vacuum Atmospher (진공 및 Argon 분위기에서 INVAR 합금에 대한 Laser-Induced Plasma의 원자 분광 특성)

  • 오기장;전형하;박형국;김달우;오철한
    • Proceedings of the Optical Society of Korea Conference
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    • pp.214-215
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    • 2000
  • 레이저로 발생시킨 플라즈마의 분광학적인 분석은 유용한 분석기술로 평가되고 있다. 이러한 플라즈마를 발생시키는데 있어서 Q-switched 레이저를 많이 사용되고 되고 있으나, Q-switch된 레이저로 발생시킨 플라즈마 복사광의 특성은 주변 분위기에 의해 매우 큰 영향을 받는다. 특히 대기압인 공기분위기에서 레이저로 발생된 플라즈마의 분광특성은 강하고 연속적인 background가 포함되고, 자체적으로 흡수되고, 넓게 퍼진 분광선들이 생성된다. 이는 레이저 발생 플라즈마를 통해 성분을 분석할 경우에 적합하지 않다. (중략)

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Selective Laser Sintering of WC-Co Mixture (텅스텐 카바이드와 코발트 혼합물의 선택적 레이저 소결)

  • 김광희;조셉비만
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • pp.269-274
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    • 2001
  • This paper describes the experimental results on direct selective laser sintering of WC-Co mixture. The experiments were carried out within an air, argon and nitrogen atmosphere. The main problem occurred during sintering within an air atmosphere was oxidation of WC-Co mixture. As the power of laser is increased and scanning speed is decreased, more severe oxidation takes place. Within an argon and nitrogen atmosphere the oxidation is reduced significantly. As the energy density is increased the thickness of the sintered layer is increased.

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Etching of Silicon Wafer Using Focused Argon lon Laser Beam (집속 아르곤 이온 레이저 빔을 이용한 실리콘 기판의 식각)

  • Cheong, Jae-Hoon;Lee, Cheon;Park, Jung-Ho
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.48 no.4
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    • pp.261-268
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    • 1999
  • Laser-induced thermochemical etching has been recognized as a new powerful method for processing a variety of materials, including metals, semiconductors, ceramics, insulators and polymers. This study presents characteristics of direct etching for Si substrate using focused argon ion laser beam in aqueous KOH and $CCl_2F_2$ gas. In order to determine process conditions, we first theoretically investigated the temperature characteristics induced by a CW laser beam with a gaussian intensity distribution on a silicon surface. Major process parameters are laser beam power, beam scan speed and reaction material. We have achieved a very high etch rate up to $434.7\mum/sec$ and a high aspect ratio of about 6. Potential applications of this laser beam etching include prototyping of micro-structures of MEMS(micro electro mechanical systems), repair of devices, and isolation of opto-electric devices.

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Output Enhancement of Rhodamine 6G Dye Laser by Rhodamine 560 Energy Transfer Dye (Rhodamine 560을 이용한 rhodamine 6G 색소 레이저의 출력 증가)

  • 장원권;이민희
    • Korean Journal of Optics and Photonics
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    • v.5 no.2
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    • pp.266-271
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    • 1994
  • The output power and the energy of Rh-6G dye laser were enhanced by the mixture of Rh-560 dye whose fluorescence spectrum was coincident with the absorption spectrum of Rh-6G. The argon filled coaxial flashlamp used for pulsed pumping and argon laser for CW pumping. The concentration of Rh-6G dye was optimized in each pumping method before Rh-560 dye was mixed in Rh-6G dye solution. In the coaxial flash lamp pumped Rh-6G laser the output energy was increased about 30% when Rh-560 was mixed at 1% of Rh-6G concentration. In the case of argon laser pumping with multiline, the output power was increased 18% at the concentration of 2.5%. In the single line laser pumping, the output power was enhanced more efficiently. The power enhancements were 72% and 88% when the pumping wavelengths were 488 nm and 514.5 nm respectively. ively.

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A COMPARATIVE STUDY OF THE EFFECTIVENESS IN POLYMERIZATION OF COMPOSITE RESIN CURED WITH VISIBLE LIGHT AND ARGON LASER SOURCE (가시광선과 아르곤 레이저에 의한 복합레진 중합 효과의 비교 연구)

  • Jun, Sang-Eun;Kim, Yong-Kee
    • JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY
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    • v.23 no.2
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    • pp.327-346
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    • 1996
  • The purpose of this study was to evaluate the shear bond strengths, microhardness, compressive strength and contraction gap at the resin-tooth interface of two types of composite resins polymerized with visible light and argon laser sourse. The results from the present study can be summarized as follows ; 1. Resin samples polymerized either by argon laser or visible light did not show significant difference in their physical properties tested(p>.05). 2. The contraction gap at the resin tooth interface was found to be present in all samples but any significant difference between groups could not be established due to their variability. Although the superiority of argon laser over visible light in enhancing the physical properties of resin could not be elucidated in the present study, continous efforts are deemed to be worthwhile to investigate this area using different conditions and materials of experiment.

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T-joint Welding Characteristics of Multi-thin Plate Dissimilar Thickness of SS41 of Automobile Battery by using Nd:YAG Laser (Nd:YAG 레이저를 이용한 자동차 배터리용 SS41 다층박판 이종두께 T형상 용접 특성)

  • Yang, Yun-Seok;Hwang, Chan-Youn;Yoo, Young-Tea
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.10
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    • pp.1078-1088
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    • 2012
  • In this paper, we present research experimental results about the different thickness T-joint welding of the high power continuous wave(CW) Nd:YAG laser for the secondary battery of a vehicle. Although the conventional method used for the secondary battery is a argon TIG welding, we utilize a laser welding to improve Tungsten Inert Gas(TIG) welding's weakness. The laser, which has a couple of advantage such as aspect ratio, low Heat Affected Zone(HAZ), good welding quality and fast productivity utilized in this work is a CW Nd:YAG laser. In order to observe laser welding sections, we used a optical microscope. Through the analysis of the metallographic, hardness, aspect ratio, and heat input, we obtained the desired data in condition of 1800 W laser beam power and 1.8 m/min and 2.0 m/min laser beam travel speeds. In order to compare electric resistances of the argon TIG welding and laser welding, we made an actual battery and the electric resistance of the laser welding is reduced by 40~45% comparing with the argon TIG welding.

CLINICAL APPLICATION OF ARGON LASER IN PEDIATRIC DENTISTRY (아르곤 레이저의 소아치과에서의 임상적 적용)

  • Lee, Mi-Na;Lee, Sang-Hoon;Kim, Chong-Chul
    • JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY
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    • v.24 no.1
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    • pp.139-147
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    • 1997
  • Argon laser used in this case report, is special in having two wavelength of 488, 514nm blue-green visible light spectrum. Blue light is used for composite resin polymerization and caries detection. Green light is used for soft tissue surgery and coagulation. Maximum absorption of this laser light occurs in red pigmentation such as hemoglobin. The argon laser may be well-suited for selective destruction of blood clots and hemangioma with minimal damage to adjacent tissues. Argon laser light penetrates tissue to the 1 mm depth, so its thermal intensity is lower than $CO_2$ laser light. Also, due to its short wavelength it can be focused in a small spot and even single gene can be excised by this laser and microscopy. After applicating argon laser to 4 patient for surgical procedure and to 1 patient for curing the composite resin, following results were obtained. 1. Improved visibility were gained due to hemostasis and no specific technique were needed according to easy recontouring of the tissue. 2. Ability to use by contact mode, tactile sense was superior but tissue dragability and accumulation of tissue on the tip needed sweeping motion. 3. Additive local anesthetic procedure was needed. 4. No suture and less curing time reduced chair time, this made argon laser available in pediatric dentistry.

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