• 한국치위생학회지
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• 제14권4호
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• pp.585-591
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• 2014

Objectives : The purpose of this study was to investigate of the color change, tooth surface and intra-pulpal temperature of tooth bleaching by light activation Methods : Forty-eight extracted bovine teeth were immersed into a tea solution for 24 hours. The specimens were randomly divided into four groups(n=15):(G1) 15% HP + without light activation, (G2) 15% HP + light activation, (G3) 25% HP + without light activation, (G4) 25% HP + light activation. All specimens were bleached for 15 minutes three times. The spectrophotometer (CM-2600d, Konica Minolta, Osaka, Japan) was used including before bleaching, immediately after bleaching, 1 week, 1 and 3 months after the end of bleaching. The temperature rise were measured in the pulpal chamber and tooth surface with a digital thermocouple thermometer(Termopar Digital Multimeter, Tektronix DMM916, USA). Between the tested time points, the specimens were stored in distilled water. The data were analyzed by ANOVA, t-test and Tukey's post hoc test set at 0.05. Results : There was no significant color change by the use of light after the bleaching treatment(p>0.05). The dental bleaching treatments of teeth with 15% HP and 25% HP did not seem to be more effective when light source was used. There was no difference in color stability between groups within three month(p>0.05). There was an increase in tooth surface and pulp temperature, but it was not sufficient to cause damage to the pulp. Conclusions :The use of light activation has no obvious effective impact on the tooth bleaching effect.

• Journal of Ginseng Research
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• 제11권2호
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• pp.91-100
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• 1987

인삼(Panax ginseng C.A. Meyer) 엽소병에 대한 고사원인을 현상학적 측면에서 관찰, 분석한 결과 chlorohphyll의 bleaching현상은 적색광(660~700nm)에서 일어났으며, 청색광(400~500nm)에서는 광산화에 의한 bleaching현상이 일어나지 않았다. 엽소병에 의한 고사원인으로 대두되었던 환경요인 "온도"는 chlorohphyll의 bleaching현상에 전혀 영향을 미치지 않았다. 따라서 단순연소(simple burning)설은 본 실험을 통해 배재되었으며, 낮은 pH는 chlorohphyll의 bleaching속도를 가속화시켜 주었다. 엽소병에서 chlorohphyll의 bleaching현상을 유발시키는 1차적요인은 인삼잎의 독특한 구조적 차이에 의한 것이었다.

• 한국잡초학회지
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• 제9권3호
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• pp.230-237
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• 1989

Bleaching herbicides(oxyfluorfen, oxadiazon, paraquat)의 작용발현에 영향을 미치는 온도 및 광의 효과를 조사한 결과 oxyfluorfen 과 oxadiazon의 제초활성은 $10-35^{\circ}C$에서 온도가 증가될수록 높았으며 온도의 효과는 제초작용 발현단계(photooxidation) 보다는 그 이전 단계에서 더욱 큰 영향이었다. 처리약제 모두 광도가 높을수록 활성이 강하였으며 paraquat 는 광질간의 활성차이가 없었으나 oxyfluorfen 및 oxadiazon 은 챙색광에서 높은 활성을 보였고 이들 두 약제에 대한 광의 효과는 광합성 및 호흡의 전자전달계나 carotenoid 생합성 보다는 chlorophyll 생합성 과정과 일정한 관련이 있다.

• Restorative Dentistry and Endodontics
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• 제19권1호
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• pp.169-179
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• 1994

The purpose of this study was to compare and evaluate the bleaching efficacy of three nonvital bleaching techniques: Walking bleaching, Walking bleaching and heat application, and Walking bleaching and bleaching light application. 36 extracted anterior teeth with intact crowns were immersed in 5 % sodium hypochlorite solution for twenty-four hours to loosen extrinsic debris. Lingual access openings were prepared in all teeth and the pulps were extirpated. The teeth were stored in 5% sodium hypochlorite for twenty-four hours to open the dentinal tubules and they were stained via whole blood. Once the teeth were stained, they were evaluated with Colorimeter. The teeth in each group were ranked from lightest to darkest and divided equally into three experimental groups in which the following bleaching techniques were used. Intracoronal base was placed 2mm below cementoenamel junction. Group 1 Walking bleaching (Superoxol + Sodium perborate) Group 2 Heat application + Walking bleaching (Superoxol+Sodium perborate) Group 3 Light application+Walking bleaching (Superoxol+Sodium perborate) The bleaching agents were changed every 3 days and the teeth were bleached for a total of 14 days. The teeth were evaluated with Colorimeter before the start of any bleaching and on day 14. The results were as follows: 1. At the end of 14 days, all the sample teeth demonstrated the increase of Lightness Index at cervical 1/3 of crown (p<0.05) Lightness Index was significant difference in group 2 and 3, but there were some minor differences among groups (p>0.05). 2. In all groups, there was significant difference in red chromacity (p<0.05), but there were some minor differences among groups (p>0.05). 3. In all groups, there was no significant difference in yellow chromacity (p>0.05).

• Restorative Dentistry and Endodontics
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• 제47권1호
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• pp.7.1-7.14
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• 2022

Objectives: This study evaluated the bleaching efficacy of different in-office protocols associated with violet light emitting diode (V-LED), and measured the pulpal temperature rise caused by V-LED with or without gel application. Materials and Methods: Bovine incisors were distributed in 4 groups (n = 10): VL - V-LED; HP - 35% hydrogen peroxide (control); HYB - hybrid protocol, V-LED applied without gel for 10 irradiation cycles followed by V-LED applied with gel for another 10 irradiation cycles; and HPVL - gel and V-LED applied for 20 irradiation cycles. Three bleaching sessions were performed with 7-day intervals. Bleaching efficacy was evaluated with ΔE_ab^*, ΔE₀₀ and ΔWI_D. Data were recorded at baseline, 7, 14, 21 and 70 days. For pulpal temperature rise, thermocouples were placed inside the pulp chamber of human incisors. To determine intrapulpal temperature, the teeth were irradiated with V-LED with or without application of bleaching gel. Color difference data were analyzed by 2-way repeated measures ANOVA and Tukey's test. Pulpal temperature was analyzed by t-test (α = 5%). Results: VL exhibited lower color (ΔE_ab^* and ΔE₀₀) and whiteness changes (ΔWI_D) than the other groups. HPVL presented higher color change values than HYB. HYB and HPVL showed not different ΔWI_D values; and HP showed the highest whiteness changes at all times. There were significant differences comparing ΔT with gel (8.9℃) and without gel application (7.2℃). Conclusions: HPLV was more efficient than HYB. The 2 protocols with VL showed similar results to control. Gel application combined with VL promoted higher pulpal temperature than to the no gel group.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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• pp.381-386
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• 2006

Many different types of bleaching chemicals and processes have been globally used for deinked pulp. Besides chlorine-free bleaching chemicals, hydrogen peroxide, and sodium dithionite that could be used without restriction for almost all types of fibers, chlorine-containing chemicals such as chlorine dioxide and sodium hypochlorite have also used throughout the world. Even though hydrogen peroxide is commonly used in newsprint, it could not effectively increase brightness. Experimental evaluation on the possibility of using formamidine sulfinic acid (FAS), a reducing agent, for bleaching a wood-containing deinked pulp has been carried out in this study. The effect of bleaching efficiency for FAS on operational conditions and chemical concentrations compaired to hydrogen peroxide in one and two stages was studied. FAS bleaching showed higher brightness at high temperature and low consistency, and vice versa for peroxide one. Bleaching with sodium silicate and DTPA in FAS and peroxide stage showed better results than cases without them. Sodium silicate and chelant seemed minimize the influence of transition metal ions, including manganese and iron ions, which induce both bleaching agents to decompose. As a result, FAS as a reducing agent seems more effective than hydrogen peroxide for increasing brightness and reducing yellowness. FAS and FAS sequence seemed more efficient than the other two stages of bleaching sequences with regard to the best brightness level obtained. When bleaching was conducted with FAS, COD load was just about one-third compared to peroxide, and brightness stability of the bleached pulp appeared better than peroxide after UV light irradiation.

• 대한심미치과학회지
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• 제7권1호
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• pp.6-17
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• 1998

치아미백은 100여년전 이상부터 시행되어 왔으나, 지난 4반세기 동안의 생활치아 미백술의 표준적인 방법은 과산화수소와 열원을 사용하거나, 열원과 광원을 복합해서 사용하는 것이었다. 이 술식의 단점은 술식의 복잡성, 많은 비용, 결과의 불확실성과 환자의 불편이었다. 1989년 3월에 치과계에서는 Haywood와 Heyman에 의해 발표된 새로운 생활치아 미백술(Night Guard Vital Bleaching)을 도입했다. 치아구조에 대한 carbamide peroxide의 화학적 효과를 알고 있었으면 수년 전에 개발되었을 아주 간단한 치료술식이다. 이 방법은 시술이 쉽고, 사용 되는 재료의 높은 안전성, 낮은 치료비, 높은 성공률로 최근 다시 치아미백 붐을 일으키는데 일조를 하고 있으며, 생활치아 미백술의 표준적인 방법으로 신속히 자리잡아가고 있다.

• Restorative Dentistry and Endodontics
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• 제25권4호
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• pp.599-605
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• 2000

Among the effects of tooth bleaching on composite resins, degree of color change and dye deposition onto composite resins after office bleaching were investigated in vitro. Seventy two disc-shaped resin samples were fabricated with hybrid type composite resin, Z-100 under 3 different environments(24 samples for each environment) characterized by 3 kinds of light-curing intensity and duration($250mW/cm^2$-20sec., $250mW/cm^2$-40sec., $550mW/cm^2$-20sec.). As control, one-third samples of each group were not treated with bleaching agent. The remaining two-thirds samples of each group were treated with bleaching agent(bleaching group). Then, before thermocycling procedure in coffee bath, the half of the samples treated with bleaching agent were polished(polishing group) with polishing system. SofLex, but the other half(not-polishing group) and control group were not polished. Another 72 samples were also made with microfilled type composite resin. Sillux Plus and treated according to the experimental procedures mentioned above. The color of each resin sample was measured before bleaching, after bleaching, and after thermocycling preceded by bleaching. And color difference was evaluated. It was concluded as follows: 1. The amount of color change of resin samples after office bleaching was not statistically significant(p>0.05). But the samples which were treated with bleaching agent showed more color change than that of control group. 2. After thermocycling in coffee bath, the amount of color change of resin samples between control and bleaching group was not statistically significant(p>0.05). 3. After thermocycling in coffee bath, the polishing procedure of resin samples showed no statistically significant difference(p>0.05) between polishing and not-polishing group in the aspect of color change.

• Journal of Ginseng Research
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• 제14권2호
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• pp.135-141
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• 1990

In order to elucidate the mechanism of the leaf-burning disease of ginseng (Panax ginseng C.A. Meyer), the relationships between thylakoid membrane peroxidation and chlorophyll bleaching were investigated in comparison with the ones of soybean (Glycine max L). When I measured the rate of lipid peroxidation in the thylakoids of ginseng and soybean by irradiation of light(60 w.m-2), it was identified that, the remarkably lower rate of lipid peroxidation was found in the ginseng thylakoid than the case of soybean. When lipid peroxidation of ginseng thylakoid was induced in the dark, chlorophyll contents of thylakoid was not changed. The results suggest that lipid peroxidation does not affect the chlorophyll bleaching in ginseng thylakoid. Thylakoid membrane peroxidation as well as chlorophyll bleaching was closely related with photosynthetic electron transport. But, according to the quenching experiment active oxygen species induced lipid peroxidation may be different species in the case of chlorophyll bleaching.

• 한국식품과학회지
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• 제12권2호
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• pp.82-87
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• 1980

고추 가루 저장(貯藏) 시(時) 일광(日光) 노출(露出) 하(下)에서 일어나는 표면적색소(表面赤色素)의 탈색(脫色) 현상을 일사량(日射量), 고추의 건조(乾燥) 방법(方法), 고추 가루의 입도(粒度), 수분(水分) 활성도(活性度) 및 광(光) 파장(波長)등의 제반 인자(因子)들과 관련하여 연구하여 다음과 같은 결과를 얻었다. 1. 고추 가루를 일광(日光)에 노출시킬 때 고춧가루의 표면색(表面色)은 적색소(赤色素) 보지솔(保持率)(잔존(殘存) capsanthin 함양(含量)/초기(初期) capsanthin 함양(含量)이 0.5에 이를때 까지 급격히 감소되었으며 그후에는 완만한 감소 현상을 보였다. 2. 일정한 광량(光量)을 조사(照射)할 때 고추의 건조 시간이 길었던 고추 가루와 입자가 작은 것일수록 탈색 현상이 심하였다. 3. 일광 탈색 현상에 고추가루의 수분 활성도의 영향이 뚜렷하였으며 $a_w$값이 0.5이하(以下)에서는 그값이 낮을수록 탈색 반응이 촉진되었으며, $a_w$이 0.5이상에서 는 별로 큰 변화를 나타내지 않았다. 4. 광(光) 파장(波長)이 짧을수록 탈색 반응을 촉진하였다. 따라서 고춧가루의 적색소(赤色素) 보존(保存)을 위해서는 적색(赤色) 포장 필름을 사용함이 바람직하다.