• The Journal of Korean Physical Therapy
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• v.13 no.3
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• pp.603-611
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• 2001

This study was performed. using EGF, to observated the effect of GaAIAs laser on wound model induced designedly in lumbar region. The results of this study were as following: 1. In expression of EGF which used marker of wound healing, laser irradiating group made EGF to more induce significantly than laser non-irradiating group at 3 days. 2. EGF immunoreactivity in epidermis were increased markedly 3 days after wound, and increased gradually from 1 day to 2 days in wound which is laser irradiation. Therefore, EGF immunoreactivity which increased after wound with GaAIAs laser irradiation indicate that GaAIAs laser have wound healing effect. This study also can become a part of scientific evidence on electrotherapy through measuring quantitively effects of GaAIAs laser in wound

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.679-683
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• 2005

In this study, we investigate the characteristic of the poly-Si grain and morphology influenced by XeCl excimer laser system. The stable laser beam source is basic requested; the irradiation beam through optical lens module is more important which limit the grain size smaller than $0.5{\mu}m$. The homogenization lens designs control the poly-Si grain size; so we hardly get enlarge grain size by one laser irradiation scan.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.3
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• pp.439-447
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• 2003

This was performed to evaluate the inhibitory effect of laser on the growth of S. mutans. The bacterial pallets containing S. mutans KCTC 3065 were irradiated with Er:YAG laser and Nd :YAG laser by non-contact method at an intensity of 50mJ for 5 sec with the pulse repetition rates of 10Hz and 30Hz, respectively. The following results were obtained on colony count, acid producing ability, and the amount of insoluble extracellular polysaccharide synthesis. 1. The irradiation of Nd:YAG laser after photosensitization with Chinese ink inhibited the proliferation of S. mutans the most, and the irradiation of Er:YAG also inhibited the proliferation. However, the irradiation of Nd:YAG laser alone could not inhibited the proliferation of S. mutans. The pulse repetition rate did not affect significantly on the proliferation of bacteria in overall. 2. The irradiation of Nd:YAG laser after the photosensitization with Chinese ink inhibited the acid production of S. mutans the most for a certain period of time. Er:YAG laser also inhibited acid production. When Nd:YAG laser was used alone, the acid production of S. mutans was not been inhibited. The irradiation of Nd:YAG laser after photosensitization with Chinese ink inhibited the acid production ability of bacteria the most as the pulse repetition rate increased. 3. Laser irradiation did not inhibited the synthesis of insoluble extracellular polysaccharide of S. mutans. From these results, we conclude that the irradiation of Er:YAG laser and Nd:YAG laser after photosensitization with Chinese ink would inhibit the proliferation and acid production by S. mutans, which may prevent dental caries. However, this effect does not last long time so that the laser irradiation should be repeated frequently in order to obtain clinical effect; thus, this laser irradiation would not have a clinical usefulness in preventing dental caries when used solely.

• The Journal of Internal Korean Medicine
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• v.21 no.5
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• pp.799-803
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• 2000

Objective : This study was designed to assess effects of He-Ne laser irradiation on high-level of Total Cholesterol and Triglyceride. Methods : The 76 patients who have been checked Total Cholesterol and Triglyceride high were divided into a study group of patient who were irradiated and into a control group of patients who did not receive irradiation.. Then, patients rechecked Total Cholesterol and Triglyceride after 1 month later. Results : In patients of study group, The level of Total Cholesterol and Triglyceride was decreased. But In comparison with control group, there was no significant effect of decrement of Total Cholesterol and Triglyceride. Conclusions : These results suggest that He-Ne laser irradiation may have no significant decrement effects on high-level of Total Cholesterol and Triglyceride.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.423-423
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• 2009

Currently, lasers are one of the most popular light sources in use for medical treatment. Many studies on low power lasers are being done in cell culture or through animal tests and most report different findings, making it difficult to verify their true effects. There are shifts in trends of studies from laser and LED that are expensive and generate heat problem to LED that are economically effective and safe. Its near infrared rays can penetrate deep into skin or muscle, up to 23 cm, without causing thermal damage or impairing neighboring tissues. This study verified the performance and effectiveness of an LED irradiator that was designed to emit similar wavelengths to that of a laser and thus could be used instead of a low level laser therapy in experiments on animals. And then, each experiment was performed to irradiation group and non-irradiation group for NTacSam:SD tissue cells. MIT assay method was chosen to verify the cell increase of two groups and the effect of irradiation on cell proliferation was examined by measuring 590nm transmittance of ELISA reader. As a result, the cell increase of NTacSam:SD tissue cells was verified in irradiation group as compared to non-irradiation group. The fact that specific wavelength irradiation has an effect on cell vitality and proliferation is known through this study.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.2
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• pp.368-382
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• 1998

The purpose of this study is to evaluate and compare the results of argon laser for 5 seconds, argon laser for 10 seconds, and visible light for 40 seconds photo-polymerization in compressive strength, microhardness, curing depth, temperature rising during polymerization, and polymerization shrinkage. Hybrid type composite resin(Z-100) and compomer(Dyract) were used to be compared. The compressive strength was measured by an Instron(1mm/min cross head speed) in 60 specimens and the microhardness of the surface was expressed by Vickers Hardness Number(VHN) in 30 specimens. The curing depth was evaluated comparing the different values of upper and lower VHN according to irradiation time and thickness for the light source polymerization in 60 specimens. The temperature rising during photopolymerization was observed by the temperature change with thermocouple sensitizer beneath 40 specimens at the argon laser for 10 seconds and visible light 40 seconds irradiation. The polymerization shinkage was evaluated by calculating the decrease of % volume by using a dilatometer in 30 specimens. The results were as follows ; 1. In the case of compressive strength, the argon laser polymerization groups were higher than visible light group in Z-100 (p<0.05). In Dyract, the argon laser 5 seconds group did not show a significant difference with the visible light 40 seconds group. The argon laser 10 seconds group showed the markedly low value when compared with other groups (p<0.05) 2. In microhardness, Z-100 was better than Dyract when comparing by VHNs (p<0.05); however, there was not a significant difference between two materials in the visible light 40 seconds group and the argon laser 10 seconds group. 3. In the study of curing depth, Z-100 showed the consistent polymerization in argon laser irradiation because there was no difference in the VHN decrease according to the thickness change. Over the thickness control, the results did not show a significant difference between visible light and argon laser group in Z-100; however, in the case of Dyract, the visible light 40 seconds group was better than the argon laser groups(p<0.05). 4. There was a significant difference between the two materials in temperature rising during polymerization (p<0.05), but not a significant difference between irradiation times, 5. There was not a significant difference between the two materials in polymerization shrink age. The argon laser 5 seconds group was smaller than the other groups (p<0.05). It could be concluded that Z-100 polymerization was recommended to use the argon laser for reduction of the irradiation time while Dyract was recommended to use the visible light polymerization.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.7
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• pp.674-678
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• 2008

Low level laser therapy has various therapy effects. This paper performed the basic study for fabricating the low level laser therapy apparatus, and one of the goals of this paper was to make this apparatus used handily. The apparatus has been fabricated using the laser diode and microprocessor unit. The apparatus used a 635 nm laser diode for laser medical therapy and was designed for a pulse width modulation type to increase stimulation effects. In this study, the designed device was used to find out how 635 nm laser diode affected the skin injury of SD-Rat(Sprague-Dawley Rat). We divided the participants into two groups; irradiation group which was irradiated 10 minutes a day for 9 consecutive days, and none irradiation group. The results showed that the study group had lower incidence of inflammation and faster recovery, compared with the control group.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.3
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• pp.660-677
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• 1997

The purpose of this study was to examine the morphological characteristics and combined effects of fluoride application and laser irradiation on artificial caries-like lesion formation in bovine enamel. Enamel specimens were divided into five experiment group and placed in no-treatment(group C), APF application alone(group F), laser irradiation alone(group L), APF application before laser irradiation (group FL), and APF application after laser irradiation(group LF) on artificial caries-like lesion. Sound enamel was used as a control group. The ultrastructural changes and physical effects of the fluorided and lased enamel has been investigated by using SEM, enamel solubility and microhardness test as well as distributions of calcium, phosphorus and fluoride in internal enamel by using EPMA. The following results were obtained. 1. In the all experiment groups, the amounts of dissolved calcium of enamel surfaces significantly decreased according to increasing exposure time of acid solution than control group(P<0.001). Group L showed higher than that group FL and LF in 30 and 60min(P<0.05). 2. The microhardness values of enamel surface in the control group was highest than that in the other experiment groups. Group F, L, FL and LF were significantly increased than group C(P<0.001). The enamel surface treated with APF produced deposites of numerous small globules and lased enamel showed a cracker-like appearance with microcrack and small pore. Numerous deposits were infiltrated in the fissured portion of enamel treated with APF after laser irradiation. 4. In the case of APF application alone, the elevation of the fluoride profile can be seen within $5{\mu}m$ of the outermost layer and a similar profile observed in the specimen treated with APF before laser irradiation. However, the specimen treated with APF after laser Irradiation showed a large elevation within $10{\mu}m$ of the outermost layer of the enamel. 5. The higher Ca/P ratios were observed in $10{\mu}m$ depth of lased and fluorided enamel when compared to the sound and carious enamel. The fluoride content decreased rapidly with distance from enamel surface, in the group F, fluoride concentration was significantly higher than that in the group C, L, FL, LF and control group according to increasing enamel depth (P<0.05).

• Journal of Dental Anesthesia and Pain Medicine
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• v.23 no.4
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• pp.229-236
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• 2023

Background: Local anesthesia has been reliably used to control pain during dental procedures and is important in pediatric dentistry. However, children occasionally complain of prolonged numbness after dental treatment, leading to several problems. Studies conducted to reverse the effect of local anesthesia using phentolamine mesylate and photobiomodulation therapy (PBM) are encouraging but limited. PBM is a type of light therapy that utilizes visible and near-infrared non-ionizing electromagnetic spectral light sources. Hence, this study used this modality to compare the reversal of local anesthesia at two different wavelengths. This study compared the effect of PBM at 660 and 810 nm wavelengths on the reversal of soft tissue local anesthesia using a diode LASER in pediatric dentistry. Method: Informed consent and assent were obtained, and the participants were then divided randomly into three groups of 20 children each: control group-without LASER irradiation, LASER irradiation at 660 nm, and LASER irradiation at 810 nm. Sixty children aged 4-8 years with deciduous mandibular molars indicated for pulp therapy were administered an inferior alveolar nerve block. After 45 min of injection, a duration that was similar to the approximate duration of treatment, they were exposed to 660- and 810-nm LASER irradiation according to their groups until reversal of local anesthesia was achieved. The control group did not undergo LASER irradiation. The reversal of the soft tissue local anesthetic effect was evaluated using palpation and pin prick tests every 15 min, and the LASER irradiation cycle continued until reversal of the soft tissue local anesthesia was achieved. Results: A significant reduction of 55.5 min (27.6%) in the mean soft tissue local anesthesia reversal time was observed after the application of 810 nm wavelength PBM and 69 min (34.7%) after 660 nm wavelength LASER irradiation. Conclusion: PBM with a 660 nm wavelength was more effective in reducing the mean soft tissue local anesthesia reversal duration, and thus can be used as a reversal agent for soft tissue local anesthesia in pediatric dentistry.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.1
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• pp.42-46
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• 2011

Light can be divided into ultraviolet rays, visible rays, and infrared rays depending on the wavelengths. Visible rays with specific wavelength are those predominantly used for would treatment. Especially low level laser irradiates into cells, effectively stimulating cellular tissues and activating cellular function. This study was intended to verify the effect of white LED irradiation therapy on wound recovery in animal tests by applying white LED irradiator, which was independently designed and developed to emit beams of similar wavelength to that of a laser. The designed LED Irradiator was used to find out how white LED light source affected the skin wound of SD-Rat(Sprague-Dawley Rat). We divided the participants into two groups; white LED irradiation group which was irradiated 1 hour a day for 9 consecutive days, and none irradiation group. The results showed that the study group had lower incidence of inflammation and faster recovery, compared with the control group.