• Proceedings of the KWS Conference
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• 1996.05a
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• pp.41-45
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• 1996

• Journal of Oral Medicine and Pain
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• v.30 no.4
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• pp.465-473
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• 2005

The purpose of this study was to evaluate the desensitizing effects of a Nd:YAG laser (Sunlase, SUNRISE Technologies, Inc., USA) irradiation on cervically exposed hypersensitive dentine. 45 patients was irradiated with pulsed Nd:YAG laser (1.5 W, 20 Hz, 75 mJ/pulse, 4 minutes) as the experimental group, 27 patients was mock irradiated as the control group. The degree of sensitivity to the thermal and tactile stimuli were determined qualitatively with an evaporative stimulus defined as two times air blast at a distance of 3 mm from each site to be tested and with a mechanical stimulus as a slightly scratching the cervical site with a dental explorer. A qualitative registration of the degree of discomfort was determined according to a numerical pain scale(NPS) in an 11-point scale in which 0= "no pain" and 10="most excruciating pain imaginable". Recordings were assessed before treatment, immediately after, 1 and 2 weeks after treatment. Pain tolerance threshold and pulp vitality were evaluated with electric pulp tester before and immediately after treatment. 1. Desensitizing of hypersensitive dentine with Nd:YAG laser irradiation was more effective than that with mock irradiation. 2. The placebo effect of mock irradiation was recognized for severe sensitive teeth($NPS\;{\geqq}\;6$), but not for moderate sensitive teeth(NPS < 6). 3. Laser irradiation did not affect the pain tolerance threshold and pulp vitality of the hypersensitive teeth. 4. Desensitizing effect of laser irradiation for the hypersensitive teeth had been continuing at least 2 weeks. It was concluded that desensitizing of hypersensitive dentine with a Nd:YAG laser is effective and the maintenance of the positive result was more prolonged than the placebo effect.

• Journal of Oral Medicine and Pain
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• v.20 no.2
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• pp.327-334
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• 1995

In order to observe the influence of pulsed Nd:YAG laser at its out-of-contact with dentin on tooth temperature, we have applied pulsed Nd:YAG laser to 2mm thick dentin sample at a point of contact and from a distance of 1mm, 2mm, 3mm and 4mm with an energy of 0.3W, 0.5W, 0.8W, 1.5W and 2.0W. They were exposed to periods of 3 seconds, 6 seconds, 9 seconds and 15 seconds respectively and measured temperature changes. The results as follows : 1. When the time ad intensity of power were constant, the temperature changes on dentin of tooth depended on the distance. The temperature increased when the laser intensity increased bu two other conditions were contact. 2. At the point of contact, the temperature has risen over $5^{\circ}C$ regrdless of intensity of the power or the time. However, there was $5^{\circ}C$ fluctuation with 0.3 W for 3 seconds treatment. 3. The temperature change was less than $5^{\circ}C$ thermal change at the distance of 1mm and 2mm respectively when lased for 3 seconds, 6 seconds, 12 seconds and 15 seconds with 0.3 W. Similar results were observed at 3 and 6 seconds treatment with 0.5 W and at 3 seconds treatment with 0.8 and 1.0W respectively. 4. It showed less than 5(C thermal change when lased for 3 seconds, 6 seconds, 9 seconds, 12 seconds and 15 seconds with 0.3W at the distance of 3mm and 4mm. The same results were seen in 3 seconds, 6 seconds and 9 seconds treatment with 0.5W and in 3 seconds with 0.8W and 1.0W respectively. As we have seen the above, the results has indicated that pulsed Nd:YAG lasing at its off contact on dentin of 2mm thickness will not cause irreversible changes if lasing intensity, lasing distance and lasing time are appropriate.

• Restorative Dentistry and Endodontics
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• v.28 no.1
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• pp.50-56
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• 2003

The purpose of this study was to evaluate the effects of EDTA and pulsed Nd :YAG laser on apical leak-age of canal obturation. Forty-eight single-rooted teeth were used in this study. The teeth were instrumented up to a size 40 K-file and irrigated with 2.5% NaOCl between each fie size. And the teeth were divided into 4 groups. In group A, the root canals were irrigated with a final flush of 5ml 2.5% NaOCl as a control group. The teeth in group B were irrigated with a final flush of 5ml 17% EDTA. The teeth in group C and D were irradiated by pulsed Nd：YAG laser(laser parameters were set at 1W, 100mJ, 10Hz, and 2W, 100mJ, 20Hz respectively). The results were as follows : 1. Apical leakage was observed in 50% of samples in group A, 30% of samples in group B, 20% of samples in group C, and 10% of samples in group D. 2. The teeth in group B had less leakage than group A, but there was no statistically significant differences(p＞0.05). 3. The teeth in group C, D had less leakage than group A, and there was statistically significant differences(p＜0.05). 4. The teeth in group C, D had less leakage than group B, but there was no statistically significant differences(p＞0.05). 5. There was no significant differences in apical leakage between group C and group D(p＞0.05).

• Journal of Welding and Joining
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• v.17 no.1
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• pp.71-76
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• 1999

The real-time holographic interferometer with digital high-speed camera is applied to the experimental study of laser induced plasma/plume in pulsed Nd:YAG laser welding. A pulsed Nd:YAG laser with 1.2 kW average power is applied to generate laser induced plume. The recording speed of the high-speed camera is 3,000 f/s. The high speed photographs of weld plume without another visualization method, are compared with the visualization photographs with holographic interferometer. The radiation intensity from the laser induced plume is recorded by the high speed photographs, which fluctuated during laser radiation and disappeared after laser end. The density distribution of the plume is recorded by the holographic visualization method. The experimental results show the process of generation of the laser induced plasma/plume, and give the feasibility of quantitative measurement of laser induced plume in laser welding.

• Journal of Electrical Engineering and Technology
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• v.6 no.2
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• pp.275-279
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• 2011

Sterilization of Escherichia coli (E. coli) is examined using a unique pulsed ultra-violet (UV) elliptical reactor based on Nd:YAG laser resonator, UV radiation from a pulsed xenon flashlamp. The light from the discharge has a broadband emission spectrum extending from the UV to the infrared region with a rich UV contained. Sterilization method by using the UV light is fast, environment-friendly and it does not cause secondary pollution. A Nd:YAG laser resonator having elliptical shape has advantage of concentrating the radiation of the UV light at two foci as the quart sleeve filled with E. coli. The primary objective of this research is to determine the important parameters such as pulse per second (pps), the applied voltage for sterilizing E. coli by using an UV elliptical reactor. From the experiment result, the sterilization effect of UV elliptical reactor is better than that of UV cylindrical reactor, and it can be 99.9% of sterilization at 800V regardless of the pps within 10 minutes.

• Journal of Oral Medicine and Pain
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• v.25 no.4
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• pp.403-411
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• 2000

The authors experienced a non-painful, elevated, dome-shaped lesion on lower lip in Korean male of 22-year-old and a non-painful, elevated, dome-shape lesion on left side of mouth floor in Korean female of 36-year-old. And diagnosed the lesions as a mucocele and a ranula respectively, based on the comprehensive evaluation of data obtained from history taking, clinical and radiologic examination and histopathological findings. In these cases, the authors removed mucocele and ranula using the pulsed Nd:YAG laser with advantage of good hemostatic effect, and so we could minimize improper tissue destruction during operation. The excisional wounds of lower lip and mouth floor had a good healing process without any symptom of pain and any signs of bleeding and infection.

• Proceedings of the KWS Conference
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• 2008.05a
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• pp.32-32
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• 2008

• Archives of Plastic Surgery
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• v.39 no.2
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• pp.143-149
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• 2012

Background : Axillary osmidrosis is characterized by an unpleasant odor, profuse sweating, and in some instances, staining of clothes that may socially and psychologically impair affected individuals. Various types of surgical procedures have been developed for the treatment of axillary osmidrosis. This study was undertaken to evaluate the effectiveness of subcutaneous pulsed neodymium: yttrium-aluminum-garnet (Nd-YAG) laser treatment for the treatment of axillary osmidrosis. Methods : Twenty-nine patients with axillary osmidrosis were included in this study. Patients were categorized according to the results of an axillary malodor grading system, and a subcutaneous pulsed Nd-YAG laser was applied to all patients. The treatment area for the appropriate distribution of laser energy was determined using the iodine starch test (Minor's test) against a grid pattern composed of $2{\times}2cm$ squares. The endpoint of exposure was 300 to 500 J for each grid, depending on the preoperative evaluation results. The results were evaluated by measurement of axillary malodor both pre- and postoperatively using the grading system and iodine starch test. Results : The average follow-up period was 12.8 months. Nineteen patients had a fair-to-good result and ten patients had poor results. The postoperative Minor's test demonstrated that there were remarkable improvements for patients with mild to moderate symptoms. Complications including superficial second degree burns (n=3) were treated in a conservative manner. A deep second degree burn (n=1) was treated by a surgical procedure. Conclusions : Subcutaneous pulsed Nd-YAG laser has many advantages and is an effective noninvasive treatment for mild to moderate axillary osmidrosis.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.4
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• pp.800-815
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• 1996

Pulsed Nd : YAG laser has been used to treat various soft tissue lesions. However, there have been warnings of using laser to treat peri-implantitis because the laser can alter the surface of implant and can rise its temperature so that it might be harmful to implant itself and its surrounding tissue. However, the study in vivo has not been done yet. The purpose of this study was to evaluate the biocompatibility to the pulsed Nd:YAG lased dental implant. 16 HA coated implants and 16 titanium plasma sprayed implants were used. They were divided 4 groups as unlased control, 0.3 watt, 1.0 watt and 2.0 watt lased groups after lasing. And they were implanted in the peritonial walls of 12 rabbits. The rabbits were sacrificed 6 weeks after implantation and the LM and EM specimems were made. 1. In the unlased implant group, both HA coated and titanium plasma sprayed implants were surrounded by fibroblasts and collagen fibers. No macrophages and inflammatory cells were seen. 2. In HA coated implants 0.3 watt, 1.0 watt lased group had a little inflammation, but in 2.0 watt lased group had scattered macrophages, a significantly larger number of chronic imflammatory cells were seen. 3. In titanium plasma sprayed implant 0.3 watt, 1.0 watt lased group had a little inflammation, but in 2.0 watt group had severe inflammation as in the conditions of HA coated group. 4. The inflammatory reaction of both lased HA coated and titanium plasma sprayed implant groups increased as the increase of the power of the laser.