• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2001년도 추계학술대회(제116회) 및 13회 Workshop 제3회 한ㆍ일 치과보존학회 공동학술대회 초록집
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• pp.591.1-591
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• 2001

This study was performed to evaluate internal bleaching effect of various bleaching agent on discolored nonvital teeth. 40 Human teeth were intentionally discolored with erythrocytes of human blood and randomly divided into 4 groups: 10% carbamide peroxide gel (Opalescence, Ultradent, U.S.A.); 15% carbamide peroxide gel; sodium perborate (Duksan pure chemical Co., Korea) with distilled water; sodium perborate with 30% hydrogen peroxide (Duksan pure chemical Co., Korea).(omitted)

• 대한소아치과학회지
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• 제30권3호
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• pp.423-430
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• 2003

최근 들어 심미적 목적으로 치아 미백제를 이용한 치아 미백술이 널리 사용되고 있다. 현재까지 치아 미백제의 정확한 기전은 밝혀져 있지 않지만 미백제로부터 여러 가지 방법으로 분해된 free radical의 복잡한 산화작용에 의한 것으로, 치아변색의 원인물질의 화학적 구조가 바뀌어짐으로써 희게 되는 것으로 이해하고 있다. 본 연구의 목적은 치아 미백제에 의한 상아질의 특성변화를 관찰하고 미백제의 안전성을 평가하고자 하였다. 이를 위해 10% carbamide peroxide를 1일에 6시간 2주동안 사람의 소구치 법랑질에 적용한 후 상아질에서 나타나는 형상변화, 경도변화, 조성변화 및 무기질 함량변화를 주사전자현미경(SEM), 미세경도기, FT-Raman 분광기 그리고 전자탐침미세분석기(EPMA)를 이용하여 분석하고 다음과 같은 결과를 얻었다. 법랑질 표면에 도포한 10% carbamide peroxide가 상아질로 침투하여 미친 영향은 증류수에만 담가둔 시료와 비교하였을 때 형상변화의 측면에서는 차이를 발견할 수 없었다. Peritubular dentin과 intertubular dentin의 표면에서는 nanometer range에서 아무런 변화를 발견할 수 없었다. 미백처리한 치아와 증류수에만 담가둔 치아의 상아질에서 통계적으로 유의한 경도의 차이를 발견할 수 없었다. FT-Raman 분석결과 상아질 구성성분 중 어떤 변화도 분광학적으로 관찰되지 않았다. 유기질에 의한 peak와 무기질에 의한 peak 모두 무시 할 수 있을 정도의 Raman intensity 변화만 관찰되었다. 무기질 함량변화를 측정한 결과 아무런 처리도 하지 않은 치아의 상아질, 증류수에만 담가둔 치아의 상아질 그리고 미백후 증류수에 담가둔 치아의 상아질에서 무기질 총량이 각각 $98.73{\pm}1.89,\;98.56{\pm}2.11,\;97.47{\pm}2.51$로 나타났다. 이들 값은 통계학적으로 유의한 차이를 보이지 않았다. 이상의 결과들로 볼 때 10% carbamide peroxide 미백이 상아질에 미치는 영향은 극히 미약하다고 판단되어 상아질에는 안전한 것으로 생각된다.

• 헤리티지:역사와 과학
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• 제44권4호
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• pp.130-141
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• 2011

본 연구에서는 넓은 pH영역에서도 증점효과를 가지는 카보풀 수지 940, 934를 가지고 중화제(sodium meta silicate, triethylamine)별 겔을 제조하여 10% 과산화요소를 첨가하고, 이에 따른 표백효과를 알아보았다. 실험 결과 메타규산나트륨(sodium meta silicate) 1.6g을 첨가한 실험군에서 표백효과의 최적 조건인 pH 10을 충족시키고 있다. 또한 각군별 대조군 Baseline 색 변화량(${\Delta}E*ab$)과 시간별 색 변화량(${\Delta}E*ab$)을 비교해 보면 1군(카보풀 940, 메카규산나트륨, 과산화요소)은 CS-2에서 112%, CS-4는 63.3%, CS-6은 87.4%의 표백효율을 나타냈으며, 2군(카보풀 934, 메카규산나트륨, 과산화요소; CS-8, CS-10, CS-12)에서는 순서대로 77.3%, 67.3%, 109.%로 나타났다. 그리고 3군(카보풀 940, 트리에탄올아민, 과산화요소;CT-1, CT-3, CT-5)에서 36.8%, 73.2%, 74% 순으로, 4군(카보풀 934, 트리에탄올아민, 과산화요소; CT-6, CT-8, CT-10)에서는 81.7%, 95.4%, 95.7%의 표백효율을 보였다. 따라서 중화제 비율이 증가함에 따라 표백표율이 높아지는 것을 알 수 있었으며 메타규산나트륨을 중화제로 첨가한 것보다 트리에탄올을 중화제로 첨가한 것이 표백효율이 다소 높은 것을 알 수 있었다. 그러나 실험에 사용된 겔의 점도는 메타규산나트륨을 첨가한 군에서 점도가 트리에탄올아민을 첨가한 겔보다 높았다. 이는 유약이 시유된 경사진 도자기 표면에 표백겔이 흐르지 않고 부착되는 장점이 될 수 있다. 그러므로 10% 과산화요소 표백겔을 만들고자 할 때 메타규산 나트륨을 첨가하면 증점효과와 원하는 표백효과를 얻을 수 있을 것으로 판단된다.

• 펄프종이기술
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• 제46권3호
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• pp.20-27
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• 2014

Nowadays, the bleaching techniques of thermomechanical pulp(TMP) are fast developing on the strength of some benefits, mainly on low production cost and good fiber property. In this study, the optimum concentration of bleaching chemicals and the environmental load of bleaching wastes were considered to improve the bleaching efficiency of thermomechanical pulp using Korean redpine(Pinus densiflora) under the peroxide-based bleaching system. The optical property of TMP after bleaching was planned to use higher grade of paper, like printing & writting paper, not general newspaper. The concentration of bleaching chemicals, NaOH, $Na_2SiO_3$ and EDTA, in hydrogen peroxide bleaching system, on the basis of O.D. pulp was closely influenced on the improvement of TMP brightness. Final target of bleaching efficiency was set up to above 76%-ISO brightness. The optimal target brightness of Korean redpine TMP was reached to 76.45%-ISO under the conditions of $H_2O_2$ 7% with NaOH 2.20%, $Na_2SiO_3$ 0.63% and EDTA 0.02%. The concentration of NaOH, $Na_2SiO_3$ and EDTA was correlated functional to the residual peroxide content of wastewater, pH value and electric conductivity of TMP fibers after bleaching treatment. The optimal bleaching conditions by controlling the addition amount of chemicals were positively contributed to the brightness stabilization and environmental load of TMP.

• 한국치위생학회지
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• 제12권3호
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• pp.533-541
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• 2012

Objectives : The purpose of this study was to evaluate the effects of tooth bleaching agent contained 35% hydrogen peroxide on the color, microhardness and surface roughness of tooth-colored restorative materials. Methods : Four types of tooth-colored restorative materials, including a composite resin(Filtek Z350 ; Z350), a flowable composite resin(Filtek P60 : P60), a compomer(Dyract$^{(R)}$ AP ; DY), and a glass-ionomer cement(KetacTM Molar Easymix ; KM) were used in the study. The specimens($8mm{\times}5mm$) were made by using a customized acrylic mold. Each material was divided into two groups equally(n=40) : experimental group(35% HP) and control group(distilled water). 35% HP group was treated 30 mim/5 days for 15 days. Each 30 minute treatment session consisted of two 15 minute cycles of gel application with 20 second light exposure. The authors measured the color, microhardness, and roughness of the specimens before and after bleaching. The data were analyzed with ANOVA and T-test. Results : 35% HP group showed an apparent color change(${\Delta}E^*$) than control group. In particular, DY and KM showed a noticeable color change and statistically significant differences(p<0.05). 35% HP group showed a reduction in microhardness. Z350 and P60 does not have a statistically significant difference(p>0.05), DY and KM showed a statistically significant difference(p<0.05). Percentage microhardness loss(PML) of control group was 0.6 to 5.5% in the group, 35% HP group was 6.6 to 34.6%. Roughness was increased in 35% HP group after bleaching. Especially DY and KM were significantly increased(p<0.05). Conclusions : Bleaching agents may affect the surface of existing restorations; therefore, they should not be used indiscriminately when tooth-colored restorations are present.

• 한국치위생학회지
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• 제13권2호
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• pp.351-360
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• 2013

Objectives : The purpose of this study was to evaluate the effects of tooth bleaching agent contained 15% carbamide peroxide on the color, microhardness and surface roughness of tooth-colored restorative materials by using pH cycling model. Methods : Four types of tooth-colored restorative materials, including a composite resin(Filtek Z350 ; Z350), a flowable composite resin(Filtek P60 : P60), a compomer(Dyract$^{(R)}$ AP ; DY), and a glass-ionomer cement(KetacTM Molar Easymix ; KM). were used in the study. Eighty-eight specimens of each material were fabricated, randomly divided into two groups(n=44): experimental group(15% carbamide peroxide) and control group(distilled water). These groups were then divided into four subgroups(n=11). All groups were bleached 4 hours per day for 14 days using pH cycling model. The authors measured the color, microhardness, and roughness of the specimens before and after bleaching. The data were analyzed with ANOVA and T-test. Results : Z350 and P60 showed a slight color change(${\Delta}E^*$), whereas DY and KM showed significantly color change(p<0.05). Among them, the greatest color change was observed in DY. Percentage microhardness loss(PML) of the distilled water group was 1.8 to 5.1%, and 15% peroxide peroxide group was 5.0 to 25.2%. Microhardness of DY and KM showed a statistically significant decrease(p<0.05). Roughness was increased in all groups after bleaching. Z350 and P60 does not have a significant difference(p>0.05), however DY and KM significantly increased more than the 0.2 ${\mu}m$(p<0.05). Conclusions : The effects of bleaching on restorative materials were material dependent. It is necessary to consider the type of the material before starting the treatment.

• Restorative Dentistry and Endodontics
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• 제26권5호
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• pp.399-408
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• 2001

Tooth bleaching has been prevailing recently for its ability to recover the color and shape of natural teeth without reduction of tooth material. However, it has been reported that bleaching procedure adversely affects the adhesive bond strength of composite resin to tooth. At the same time the bond strength was reported to be regained by application of some chemical agents. The purpose of this in vitro study was to investigate the effect of the removal of residual peroxide on the composite- enamel adhesion and also evaluated fracture mode between resin and enamel after bleaching. Sixty extracted human anterior and premolars teeth were divided into 5 groups and bleached by combined technique using of office bleaching with 35 % hydrogen peroxide and matrix bleaching with 10% carbamide peroxide for 4 weeks. After bleaching, the labial surfaces of each tooth were treated with catalase, 70% ethyl alcohol, distilled water and filled with composite resin. Shear bond strength was tested and the fractured surfaces were also examined with SEM. Analysis revealed significantly higher bond strength values. (p＜0.05) for catalase-treated specimens, but water-treated specimens showed reduction of bond strength, alcohol- treated specimens had medium value between the two groups(p＜0.05). The fracture mode was shown that the catalase group and the alcohol group had cohesive failure but the water sprayed group had adhesive failure. It was concluded that the peroxide residues in tooth after bleaching seems to be removed by gradual diffusion and the free radical oxygen from peroxide prevents polymerization by combining catalyst in the resin monomer. Therefore it may be possible to eliminate the adverse effect on the adhesion of composite resin to enamel after bleaching by using water displacement solution or dentin bonding agent including it for effective removal of residual peroxide.

• 대한심미치과학회지
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• 제4권1호
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• pp.12-22
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• 1995

The purposes of this study were to compare the bleaching efficacy of sodium perborate when mixed either with Superoxol or distilled water and to evaluate the efficacy of different location of intracoronal base on the presence of apical leakage of tested bleaching agents. Forty eight extracted human permanent incisors were stained via whole blood and canal fillings with conventional gutta percha were performed after routine biomechanical perparations. The experimental intracoronal base was placed either at the cementoenamel junction(group 3, 4) or 2mm below cementoenamel junction(group 1, 2). Walking bleaching was performed by two different combinations of bleaching agents : sodium perborate with distilled water in group 1, 3 and sodium perbrate with Superoxol in group 2, 4. The roots of the teeth were evaluated for the presence of color change to assess the leakage of bleaching agents and the cervical one-thirds of the crown were evaluated for bleaching effect from the whiteness Indea calculated by spectrophotometer. The results were as follows : 1. At the end of 12 days, all the sample teeth demonstrated the increase of Whiteness Index at cervical 1/3 of crown although there were some minor differences among groups. 2. Regardless of location of the base, sodium perborate with superoxol(group 2, 4) showed better results in bleaching than the sodium perborate with distilled water(group 1, 3). 3. Bleaching agent leaked into the root area when the base was placed 2mm below cementoenamel junction but no leakage was found when the base was placed at the cementoenamel junction.

• Restorative Dentistry and Endodontics
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• 제18권1호
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• pp.145-155
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• 1993

The purposes of this study were to compare the bleaching efficacy of sodium perborate when mixed either with Superoxol or distilled water and to evaluate the efficacy of different location of intracoronal base on the presence of apical leakage of tested bleaching agents. Forty eight extracted human permanent incisors were stained via whole blood and canal fillings with conventional gutta percha were performed after routine biomechanical perparations. The experimental intracoronal base was placed either at the cementoenamel junction(group 3, 4) or 2mm below cementoenamel junction(group 1, 2). Walking bleaching was performed by two different combinations of bleaching agents : sodium perborate with distilled water in group 1, 3 and sodium perbrate with Superoxol in group 2, 4. The roots of the teeth were evaluated for the presence of color change to assess the leakage of bleaching agnets and the cervical one-thirds of the crown were evaluated for bleaching effect from the whiteness Indea calculated by spectrophotometer. The results were as follows : 1. At the end of 12 days, all the sample teeth demonstrated the increase of Whiteness Index at cervical 1/3 of crown although there were some minor differences among groups. 2. Regardless of location of the base, sodium perborate with superoxol)group 2, 4) showed better results in bleaching than the sodium perborate with distilled water(group 1, 3). 3. Bleaching agent leaked into the root area when the base was placed 2mm below cementoenamel junction but no leakage was found when the base was placed at the cementoenamel junction.

• 한국치위생학회지
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• 제6권4호
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• pp.481-493
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• 2006

The purpose of the review article was to summarize and discuss the available information concerning the effect of bleaching on human teeth and reduced treatment on negative influence. Tooth bleaching effect was differ from extent of concentration and application period of a tooth bleaching agent, certainly full knowledge prior treatment about adverse effect possible appearance and follow clinical treatment for the least reduce. It remains unclear in how far those observation may result in significant adverse effect under clinical conditions. Nevertheless, further investigation are necessary to elucidate these aspect more precisely. The findings of the study were as follows : 1. It is recommended to delay placement of restorations after termination of bleaching therapy for at least 1-3 weeks. 2. Reduced negative influence that is clinical feasibility of catalase in protecting bleached surface against Oxygen radical. 3. The residual peroxide in tooth after bleaching seems to be removed by gradual diffusion and it may be possible to eliminate the adverse effect on tooth by using water displacement solution, ethylalcohol and aceton including it for effective removal of free radical oxygen.