• Journal of Periodontal and Implant Science
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• 제40권3호
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• pp.105-110
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• 2010

Purpose: It has been reported that low-level semiconductor diode lasers could enhance the wound healing process. The periodontal ligament is crucial for maintaining the tooth and surrounding tissues in periodontal wound healing. While low-level semiconductor diode lasers have been used in low-level laser therapy, there have been few reports on their effects on periodontal ligament fibroblasts (PDLFs). We performed this study to investigate the biological effects of semiconductor diode lasers on human PDLFs. Methods: Human PDLFs were cultured and irradiated with a gallium-aluminum-arsenate (GaAlAs) semiconductor diode laser of which the wavelength was 810 nm. The power output was fixed at 500 mW in the continuous wave mode with various energy fluencies, which were 1.97, 3.94, and 5.91 $J/cm^2$. A culture of PDLFs without laser irradiation was regarded as a control. Then, cells were additionally incubated in 72 hours for MTS assay and an alkaline phosphatase (ALPase) activity test. At 48 hours post-laser irradiation, western blot analysis was performed to determine extracellular signal-regulated kinase (ERK) activity. ANOVA was used to assess the significance level of the differences among groups (P<0.05). Results: At all energy fluencies of laser irradiation, PDLFs proliferation gradually increased for 72 hours without any significant differences compared with the control over the entire period taken together. However, an increment of cell proliferation significantly greater than in the control occurred between 24 and 48 hours at laser irradiation settings of 1.97 and 3.94 $J/cm^2$ (P<0.05). The highest ALPase activity was found at 48 and 72 hours post-laser irradiation with 3.94 $J/cm^2$ energy fluency (P<0.05). The phosphorylated ERK level was more prominent at 3.94 $J/cm^2$ energy fluency than in the control. Conclusions: The present study demonstrated that the GaAlAs semiconductor diode laser promoted proliferation and differentiation of human PDLFs.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제44권6호
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• pp.259-268
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• 2018

Objectives: The purpose of this study was to evaluate the synergic effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) and low-level laser therapy (LLLT) on bisphosphonate-treated osteoblasts. Materials and Methods: Human fetal osteoblast cells (hFOB 1.19) were cultured with $100{\mu}M$ alendronate. Low-level Ga-Al-As laser alone or with 100 ng/mL rhBMP-2 was then applied. Cell viability was measured with MTT assay. The expression levels of receptor activator of nuclear factor kappa-B ligand (RANKL), macrophage colony-stimulating factor (M-CSF), and osteoprotegerin (OPG) were analyzed for osteoblastic activity inducing osteoclastic activity. Collagen type and transforming growth factor beta-1 were also evaluated for bone matrix formation. Results: The results showed that rhBMP-2 and LLLT had a synergic effect on alendronate-treated osteoblasts for enhancing osteoblastic activity and bone matrix formation. Between rhBMP-2 and LLLT, rhBMP-2 exhibited a greater effect, but did not show a significant difference. Conclusion: rhBMP-2 and LLLT have synergic effects on bisphosphonate-treated osteoblasts through enhancement of osteoblastic activity and bone formation activity.

• Korean Journal of Acupuncture
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• 제22권2호
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• pp.163-181
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• 2005

Objective: The purpose of this study is to review research papers on low level laser therapy (LLLT) and to improve the knowledge of LLLT field. Methods: For introduction, laser characteristics, including wavelength, medium, beam size, power, and unit power were explained. In order to understand LLLT, tissue optics and light-biomatter interaction were briefly mentioned. We reviewed 21 Korean papers on laser acupuncture and LLLT on the viewpoint of laser apparatus. Results and Conclusion: We found that the description of laser apparatus employed for LLLT experiments were not fully written. Laser wavelength and power which are the most crucial parameters, were omitted in several papers. No paper had information on beam size. In order to have high efficacy, laser should be used with proper laser parameters. Conditions of irradiation area or acupoints should be considered too. Some future technology on laser acupuncture were mentioned.

• Journal of the Optical Society of Korea
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• 제17권4호
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• pp.289-295
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• 2013

Although low-level laser therapy (LLLT) has been a valuable therapeutic technology in the clinic, its efficacy may be reduced in deep tissue layers due to strong light scattering which limits the photon density. In order to enhance the photon density in deep tissue layers, this study developed an optical tissue clearing (OTC) laser probe (OTCLP) system which can utilize four different OTC methods: 1) tissue temperature control from 40 to $10^{\circ}C$; 2) laser pulse frequency from 5 to 30 Hz; 3) glycerol injection at a local region; and 4) a combination of the aforementioned three methods. The efficacy of the OTC methods was evaluated and compared by investigating laser beam profiles in ex-vivo porcine skin samples. Results demonstrated that total (peak) intensity at full width at half maximum of laser beam profile when compared to control data was increased: 1) 1.21(1.39)-fold at $10^{\circ}C$; 2) 1.22 (1.49)-fold at a laser pulse frequency of 5 Hz; 3) 1.64 (2.41)-fold with 95% glycerol injection; 4) 1.86 (3.4)-fold with the combination method. In conclusion, the OTCLP system successfully improved the laser photon density in deep tissue layers and may be utilized as a useful tool in LLLT by increasing laser photon density.

• 한국정보전자통신기술학회논문지
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• 제9권1호
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• pp.82-89
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• 2016

경제성장과 더불어 고령화 사회로 진입하여 '아름답고 건강하게 사는 욕구'와, '항 노화'에 대한 관심이 증진됨에 따라 미학 산업이 유망사업으로 부각되어 스킨케어 시장을 크게 증가시켰다. 하지만 병원이나 전문 관리업체의 관리를 받기위해서는 시간적, 공간적, 비용적 제약이 발생하여, 이를 해결하기 위해 많은 업체들이 홈 케어 방면으로 접근하기 시작했다. 세계적인 추세로 개인용 스킨케어 시장이 활성화 되었으며, 국내는 경기침체로 인한 저비용, 개인용 시장이 활성화 되었다. 우리는 이러한 점을 보완하기 위하여 가정용 스킨케어 장치를 개발하기 위해 본 실험을 실시하였다. 본 논문에서는 개인용 스킨케어 제품을 만들기 위해 저준위 레이저를 개발하고 이를 피부 미용적으로 접목시키기 위해 노력하였다. 피부에 저준위 레이저를 사용함으로써 모공을 확장시켜 피부의 진피층까지 해당 앰플을 침투시키는데 목적을 두고 실험하였으며, 의료용 저준위 레이저와의 비교를 통하여 안정성 및 성능의 효율성 유무를 판단하고 상용화 할 수 있도록 노력하였다.

• 대한한방소아과학회지
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• 제23권3호
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• pp.193-206
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• 2009

Objectives The purpose of this study is to evaluate the effects of Low Level Laser Therapy on Atopic dermatitis symptoms. Methods 19 patients (7 men, 12 women) were involved in this study. The intensity of SCORAD index (Erythema/darkening, Edema/papulation, Oozing/crust, Excoriation, Lichenification/prurigo, Dryness) and the symptom of SCORAD index (Pruritus) in two regions were measured. One region was treated by LLLT, the other region was not treated. Then a comparative study of index score of two regions was analyzed. Results After treatment, there were statistically significant differences in Edema/papulation, Excoriation (p<0.001), Oozing/crust (p<0.01), and Pruritus(p<0.05) index. Conclusions Based on the results, we concluded that LLLT is an effective in the treatment of atopic dermatitis. Also, further controlled studies with clinical cases of appropriate treatment time, wavelength, and intervals are needed.

• Physical Therapy Rehabilitation Science
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• 제3권1호
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• pp.1-6
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• 2014

Objective: Low level laser treatment (LLLT) is widely used in physical therapy practice. It is combined with physical therapy or LLLT alone. The purpose of this study is to evaluate the effectiveness of LLLT on patients' perception of general wrist pain. Design: Longitudinal study. Methods: Forty-eight subjects with wrist pain who were in the age range of 18-70 years old were examined. The subjects were asked, via an interview and a visual analog scale, to grade their wrist pain. They were asked to rotate their wrists through full range of motion and the angle at which any pain occurred was assessed. Each subject was then exposed to one of the following: 1) treatment with an infrared laser with the power turned off (placebo), 2) treatment with an infrared therapeutic laser, 3) treatment with a red therapeutic laser, 4) treatment with an ultraviolet laser, 5) treatment with a blue laser, 6) treatment with a Mickey Mouse flashlight. The duration of the treatment was 3 sessions in 3 days. Results: The results of the experiments showed that while pain was reduced both immediately after and the next day after laser therapy (p<0.05), there was no significant difference between the laser groups and the placebo group. However, the Mickey Mouse flashlight treatment groups had a greater range of motion than the laser groups (p<0.05). Conclusions: While pain was reduced in all laser groups, it was probably a placebo effect. The Mickey Mouse flashlight group probably received benefit from the heat of the flashlight.

• 한방안이비인후피부과학회지
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• 제27권2호
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• pp.33-50
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• 2014

Objective : The purpose of this study is to analyze research trends on laser output used for treatment of hair loss. Methods : We searched papers using Pubmed, NDSL, KISS, and RISS. First search used the keyword "Laser, Alopecia" in Pubmed. Inclusion criteria were last 15 years, English, related to output. Finally we searched papers using the keyword "Laser and Alopecia" in NDSL, KISS, and RISS. Inclusion criteria were the same as first research except for English. Results : A total of 43 studies were found, 28 studies were excluded and 15 studies were selected and analyzed. And of the 15 studies, 7 studies were foreign papers and 8 studies were domestic papers on clinical application of laser status. Mainly Used type of laser was a diode laser. As a result, we found that treatment group had more improvement than control group. The range of the laser-output was 1mW-150W in Alopecia laser therapy. Conclusions : Low-level (LLLT) as well as High-level laser therapy (HLLT) can be effectively used as an alternative to the treatment of alopecia. Thus, further attention and studies are needed on this topic in order to reduce the side effects and demonstrate the effectiveness clearly.

• Korean Journal of Acupuncture
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• 제32권1호
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• pp.30-38
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• 2015

Objectives : The aim of the study is to investigate the effects of low level laser treatment (LLLT) on the gait behavior in the rat model of arthritis. Methods : Knee arthritis was induced by the injection of $125{\mu}l$ of Complete Freund's Adjuvant(CFA) into the right hind knee joint cavity. Arthritic rats were divided 3 groups; arthritis group was used for control(CON), 10 min of laser treated group(LSR10), and 30 min of laser treated group(LSR30). LLLT was applied to KI 1 for 11 times under gaseous anesthesia. We performed several analyses under catwalk test including stand and swing time, duty cycle of paw steps, intensity and print area of steps, and stride length. Results : Stand and duty cycle of paw steps were increased significantly at 12 days after arthritis induction in LSR30 group. Swing time was decreased significantly at 12 days after arthritis induction in LSR10 group. In the analysis of intensity, print area and stride length, however, results did not show statistical significance during the time point of experiments. Conclusions : The data suggest that LLLT on the rat model of CFA induced arthritis showed beneficial effects by increase of stand time and duty cycle of paw steps and decrease of swing time. Therefore, LLLT could be useful option to improve gait discomfort in arthritis patients.

• Tissue Engineering and Regenerative Medicine
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• 제15권6호
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• pp.793-801
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• 2018

BACKGROUND: The aim of this study was to evaluate the combined effect of low-level laser treatment (LLLT) and recombinant human bone morphological protein-2 (rhBMP-2) applied to hypoxic-cultured MC3T3-E1 osteoblastic cells and to determine possible signaling pathways underlying differentiation and mineralization of osteoblasts under hypoxia. METHODS: MC3T3-E1 cells were cultured under 1% oxygen tension for 72 h. Cell cultures were divided into four groups: normoxia control, low-level laser (LLL) alone, rhBMP-2 combined with LLLT, and rhBMP-2 under hypoxia. Laser irradiation was applied at 0, 24, and 48 h. Cells were treated with rhBMP-2 at 50 ng/mL. Alkaline phosphatase activity was measured at 3, 7, and 14 days to evaluate osteoblastic differentiation. Cell mineralization was determined with Alizarin red S staining at 7 and 14 days. Western blot assays were performed to evaluate whether p38/protein kinase D (PKD) signaling was involved. RESULTS: The results indicate that LLLT and rhBMP-2 synergistically increased alkaline phosphatase (ALP) activity and mineralization. Western blot analyses showed that expression of type I collagen, runt-related transcription factor 2 (RUNX2), and Osterix (Osx), increased and expression of hypoxia-inducible factor 1-alpha ($HIF-1{\alpha}$), decreased more in the LLLT and rhBMP-2 combined group than in the rhBMP-2 or LLL alone groups. Moreover, LLLT and rhBMP-2 stimulated p38 phosphorylation and rhBMP-2 and LLLT increased Prkd1 phosphorylation. CONCLUSION: Combined treatment with rhBMP-2 and LLL induced differentiation and mineralization of hypoxic-cultured MC3T3-E1 osteoblasts by activating p38/PKD signaling in vitro.