• Journal of Oral Medicine and Pain
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• 제35권3호
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• pp.177-182
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• 2010

구강 내 연조직 소수술 시, 수술도, 열 요법, 전기요법, 한냉요법 등은 현재까지 사용되고 있는 고전적인 수술법이다. 하지만 이들 통상적인 수술적 방법의 문제로 멸균 상태의 유지, 공간의 제한, 출혈, 창상 치유의 문제, 흉터, 전신질환에 의한 수술의 제한 등이 있다. 최근 레이저가 또 하나의 수술법으로 널리 사용되고 있고, 통상적인 외과적 수술법에 비하여 레이저의 장점으로는 멸균상태 유지, 출혈감소, 통증 감소, 창상의 치유 촉진, 반흔 생성 억제 등이 있다. 특히 탄산가스 레이저는 조직 내수분에 최대한으로 흡수되어 $100{\mu}m$ 정도의 낮은 침투도를 가지며, 주변부 모세 혈관을 응고시켜 구강 내 소수술에 적용 시우수한 지혈 효과 및 수술 시야의 확보를 얻을 수 있다.

• Journal of Korean Dental Science
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• 제14권2호
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• pp.69-78
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• 2021

Purpose: The primary objective of this study was to evaluate the change in the temperature of the adhesive resin in polycrystalline ceramic brackets irradiated using a diode laser at different irradiation energy levels and times. Materials and Methods: For the measurement of the temperature of the adhesive resin, it was applied at the base of the ceramic bracket, a thermocouple was placed at the center of the base surface, the bracket was placed on prepared resin specimens for light curing, and a laser was irradiated to the center of the bracket slot at 5, 7, and 10 W. For the measurement of the temperatures of the enamel under the bracket and pulp cavity, extracted premolar was fixed to a prepared mold and the ceramic bracket was bonded to the buccal surface of the premolar. The Kruskal-Wallis H test and Friedman test were used for statistical analysis. Result: At 5 W, the temperature of the adhesive resin did not reach the resin softening temperature of 200℃ within 30 seconds. At 7 W, it reached 200℃ when the ceramic bracket was irradiated continuously for 28 seconds. At 10 W, it reached 200℃ when the ceramic bracket was irradiated continuously for 15 seconds. During laser irradiation, the temperature of the enamel under the bracket increased by over 5℃ within 15 seconds. Conclusion: The use of diode laser irradiation for bracket debonding should be carefully considered because the pulp cavity temperature increases by over 5℃ within the irradiation time for resin thermal softening.

• 대한의용생체공학회:의공학회지
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• 제17권4호
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• pp.491-498
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• 1996

The development of a compact two-wavelength Nd:YAG laser for dental and ENT applications is presented. The Nd:YAG resonator generates either 1.06$\mu$m or 1.32$\mu$m. The wavelength selection is made at the control panel. The Nd:YAG laser parameters at 1.06$\mu$m are ; the maximum pulse duration of 150$\mu$s, repetition rates of I-100Hz, and the maximum average power of 25W. At 1.32$\mu$m, the pulse duration is the same where the repetition rates and the maximum average power are I-30Hz and lOW respectively. High voltage power supply consists of a simmer module and two identical high voltage DC converters. In order to make a complete medical laser system, an optical fiber delivery unit, foot pedal and water spray handpiece are also developed. The wavelength selection is reliable since no movement of optical or mechanical components is required. The high voltage power supply is compact, easy to be maintained and applicable for other laser systems due to its modular design.

• 구강회복응용과학지
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• 제30권4호
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• pp.307-314
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• 2014

레이저가 치과 분야에 도입된 지 상당한 시간이 지났지만, 아직 그 효능에 대해서는 의견이 분분하다. 본 논문에서는 지각과민증과 치주 처치에 있어 레이저가 갖는 효능에 대한 최근 연구 결과들을 되짚어보고자 한다.

• 구강회복응용과학지
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• 제31권4호
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• pp.340-348
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• 2015

임플란트주위염(peri-implantitis)은 기능중인 골유착 임플란트 주위의 조직에서 생기는 사이트 별 감염성 질환이며 임플란트 후기 실패(late failure)의 원인으로 가장 높은 비율을 차지한다. 여러 연구들을 통해 미생물 침착이 임플란트주위염에 미치는 영향이 보고된 바 있으며 세균막의 제거는 임플란트주위염의 치료 시 필수조건이 된다. 최근에 여러 연구들을 통해 티타늄 임플란트에 레이저를 사용하여 표면을 살균, 정화 시키는 방법에 대한 실험이 많이 보고되고 있다. 본 논문에서는 임플란트주위염 처치에 있어 레이저가 갖는 효능에 대한 최근 연구 결과들을 문헌고찰을 통해 되짚어보고자 한다.

• 한국정밀공학회지
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• 제28권8호
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• pp.915-928
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• 2011

Titanium for dental implant application has the superior properties of biocompatibility, specific strength, and corrosion resistance. However, it is extremely difficult to find a suitable surface treatment method for sufficient osseointegration with biological tissue/bone cell and implant surface. Surface treatment technology using laser has been researched as the way to increase surface area of implant. In this study, to develop the surface treatment process with improved adhesion between implant and bone cell at the same time for superior biocompatibility, pulsed laser beam was overlapped continuously for scribed surface morphology and determination of friction coefficient. As the results, surface area and friction coefficient was increased over 2 times by the comparison with sand blasting, which is used for the conventional method. In this time, the optimal condition for laser beam power and beam irradiation speed was 13 watt and 50 mm/sec, respectively.

• Journal of Korean Dental Science
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• 제9권1호
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• pp.19-27
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• 2016

Purpose: Laser treatment has become a popular method in implant dentistry, and lasers have been used for the decontamination of implant surfaces when treating peri-implantitis. This study was performed to evaluate the effects of an Erbium-doped:Yttrium-Aluminum-Garnet (Er:YAG) laser with different settings on machined (MA), sand-blasted and acid-etched (SA), and resorbable blast media (RBM) titanium surfaces using scanning electron microscopy and confocal microscopy. Materials and Methods: Four MA, four SA, and four RBM discs were either irradiated at 40 mJ/20 Hz, 90 mJ/20 Hz, or 40 mJ/25 Hz for 2 minutes. The specimens were evaluated with scanning electron microscopy and confocal microscopy. Result: The untreated MA surface demonstrated uniform roughness with circumferential machining marks, and depressions were observed after laser treatment. The untreated SA surface demonstrated a rough surface with sharp spikes and deep pits, and the laser produced noticeable changes on the SA titanium surfaces with melting and fusion. The untreated RBM surface demonstrated a rough surface with irregular indentation, and treatment with the laser produced changes on the RBM titanium surfaces. The Er:YAG laser produced significant changes on the roughness parameters, including arithmetic mean height of the surface (Sa) and maximum height of the surface (Sz), of the MA and SA surfaces. However, the Er:YAG laser did not produce notable changes on the roughness parameters, such as Sa and Sz, of the RBM surfaces. Conclusion: This study evaluated the effects of an Er:YAG laser on MA, SA, and RBM titanium discs using confocal microscopy and scanning electron microscopy. Treatment with the laser produced significant changes in the roughness of MA and SA surfaces, but the roughness parameters of the RBM discs were not significantly changed. Further research is needed to evaluate the efficiency of the Er:YAG laser in removing the contaminants, adhering bacteria, and the effects of treatment on cellular attachment, proliferation, and differentiation.

• 대한치과보철학회지
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• 제44권6호
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• pp.734-739
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• 2006

Statement of problem. Many surface processing methods of dental implant have been developed, the laser processing is one of them. Purpose. This study was to investigate in vitro the fatigue resistance of implants treated with laser method(CSM implant, CSM Company, Daegu, Korea). Material and methods. Fatigue tests of 23 laser treated CSM implant(CSM Company, Daegu, Korea) were conducted using Instron 8871 (Load cell, 5 kN, Instron Co., England), according to ISO 14801 (2003), Results. From 300 N, each specimens were not fractured and withstood until more than 5,000,000 cycle. Conclusion. Within the limits of this in vitro study, implants treated with laser method (CSM implant, CSM Company, Daegu, Korea) have had enough rigidity and fatigue resistance to use clinically with reliance.

• Journal of Periodontal and Implant Science
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• 제32권2호
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• pp.315-324
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• 2002

The purpose of this in vitro study was to evaluate the efficiency of Er:YAG laser on calculus removal and the morphologic changes and hardness of the irradiated surface at different power settings. This experiment used human teeth which were extracted due to periodontal disease and had a band of calculus. Forty root slabs ($5{\times}5mm$) were made and divided into control group and irradiated groups. Experimental groups were as follows; Control group (root planing), Group1 (irradiated with laser at 30mJ), Group2 (irradiated with laser at 60mJ), Group3 (irradiated with laser at 100mJ). Twelve root slab embedded in resin block were used in each group. Er:YAG laser was applied under water irrigation with the tip held perpendicular to the root surface in contact mode. The treatment time was measured until the calculus was removed completely under naked eyes. The efficiency of calculus removal was evaluated by the time for removal. Morphological changes of laser irradiated site were observed under SEM and the surface hardness was measured using a VH tester. The results were as follows; 1. The efficiency of laser scaling was increased with increasing the energy level of irradiation(p<0.05). 2. The morphological changes such as carbonization, crater and scale-like defects in the irradiated root surface were frequently observed with increasing the energy level. 3. The surface hardness tended to increase at 60mJ and 100mJ irradiated groups than that of control group. From the results evaluting on the efficiency, morphological change and surface hardness, lower energy level was suggested for the clinical application of the Er:YAG laser in scaling.

• The Journal of Advanced Prosthodontics
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• 제6권1호
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• pp.22-29
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• 2014

PURPOSE. This study aimed to investigate the potential clinical application of digitized silicone rubber impressions by comparing the accuracy of zirconia 3-unit fixed partial dentures (FPDs) fabricated from 2 types of data (working model and impression) obtained from a laser scanner. MATERIALS AND METHODS. Ten working models and impressions were prepared with epoxy resin and vinyl polysiloxane, respectively. Based on the data obtained from the laser scanner (D-700; 3Shape A/S, Copenhagen, Denmark), a total of 20 zirconia frameworks were prepared using a dental CAD/CAM system (DentalDesigner; 3shape A/S, Copenhagen, Denmark / Ener-mill, Dentaim, Seoul, Korea). The silicone replicas were sectioned into four pieces to evaluate the framework fit. The replicas were imaged using a digital microscope, and the fit of the reference points (P1, P2, P3, P4, P5, P6, and P7) were measured using the program in the device. Measured discrepancies were divided into 5 categories of gaps (MG, CG, AWG, AOTG, OG). Data were analyzed with Student's t-test ($\alpha$=0.05), repeated measures ANOVA and two-way ANOVA (${\alpha}=0.05$). RESULTS. The mean gap of the zirconia framework prepared from the working models presented a narrower discrepancy than the frameworks fabricated from the impression bodies. The mean of the total gap in premolars (P=.003) and molars (P=.002) exhibited a statistical difference between two groups. CONCLUSION. The mean gap dimensions of each category showed statistically significant difference. Nonetheless, the digitized impression bodies obtained with a laser scanner were applicable to clinical settings, considering the clinically acceptable marginal fit ($120{\mu}m$).