• Journal of dental hygiene science
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• v.13 no.1
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• pp.13-19
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• 2013

This study evaluated the change of color and the microhardness according to time-out using the office bleaching with in vitro test after bleaching one time 1 day per week, total three times, for the control group and three times per 1day for the experimental group. $L^*$ was increased in both groups. Group 1 showed a significant increase statistically between before and after tooth whitening (p<0.05). Group 2 showed a significant increase statistically between before and after tooth whitening (p<0.05). ${\Delta}E^*$ was huge in both groups. In group 1, it was great in terms of statistical significance between 1 day and 7 days after tooth whitening (p<0.05). In group 2, it was the greatest between before and 1 day after tooth whitening and was significant statistically as well (p<0.05). Vickers hardness number (VHN) decreased in both groups. In group 1, VHN decreased over time and the difference was significant statistically (p<0.05). In group 2, VHN decreased over time and the difference was significant statistically (p<0.05). Percentage microhardness loss was great in both groups. In group 1, it was the greatest between 1 day and 7 days after the treatment, and it was significant statistically (p<0.05). In group 2, it was the greatest between before and 1 day after the treatment, and it was significant statistically (p<0.05). Put together, the more frequent tooth whitening a day is, the longer the period of tooth whitening when applying the same frequency, the greater color change was, however the microhardness decreased, in regard to the results over time using 15% hydrogen peroxide tooth whitening product for professionals.

• The Journal of the Korea Contents Association
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• v.18 no.10
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• pp.403-414
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• 2018

The purpose of this study was to investigate the knowledge and satisfaction of tooth bleaching. From June 1st, 2017, 328 patients who visited a dental clinic in Ulsan Metropolitan City for two weeks were asked to do a self - filling questionnaire. As a result of the study, the tooth bleaching satisfaction according to tooth bleaching knowledge was not statistically significant (p<0.05), and the highest(8-10) degree of satisfaction was 3.86 when the knowledge of tooth bleaching was high, and the lowest(0-3) was 3.00. The tooth bleaching satisfaction according to general characteristics was significantly different in age and gender. The score of women were 3.74 and higher than men's 3.11 The tooth bleaching experience and tooth bleaching satisfaction were statistically significant (p <0.05) and professional tooth bleaching (4.41) was higher than OCT bleaching (2.64). Also, when the tooth bleaching was done by the invitation of the hospital, it was higher than the case of experiencing tooth bleaching through media advertising. Therefore, the satisfaction of tooth bleaching is required not only for general characteristics but also for tooth tooth bleaching, and it is influenced by tooth bleaching method and tooth bleaching motivation. These factors may be useful to establish a treatment plan to improve the satisfaction of tooth bleaching.

• Journal of dental hygiene science
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• v.10 no.2
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• pp.95-100
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• 2010

The purposes of this study were to examine the effect of different fluoridated bleaching solution on the changes in physical and chemical characteristics of tooth. Forty-eight bovine incisors were divided into four groups to receive bleaching treatments, over a 14days period, as follows: no treatment; 10% carbamide peroxide (CP) bleaching; 10% CP containing 0.05% fluoride; and 10% CP containing 0.1% fluoride. All the specimens were highly polished and discolored with commercial COCK.Color and enamel changes were determined with colorimeter, microhardness tester, scanning electron microscope, atomic force microscopy. All the collected data were analyzed with one-way ANOVA. After the bleaching, bleached groups showed the color change(E*). Microhardness of 10% CP group decreased after tooth bleaching. But microhardness of containing fluoride bleached groups increased after tooth bleaching. Enamel surface of 10% CP bleached group showed any apparent morphology and roughness changes compared to the enamel which was stored in distilled water only. These results demonstrated that Fluoridated 10% Carbamide Peroxide have appreciable bleaching effect on bovine teeth and were not adversely affects enamel. Supporting influence of fluoride-containing bleaching solution on remineralization could be observed and further research must be carried out in various active environments to confirm these results clinically.

• Restorative Dentistry and Endodontics
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• v.31 no.6
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• pp.470-476
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• 2006

The objective of this in situ study was to evaluate the effects of whitening strip (Claren, LG Household & Health Care Ltd, 2.6% hydrogen peroxide) and gel (Opalescence, Ultradent, 10% carbamide peroxide) on microhardness of enamel in comparison with untreated control. Extracted twenty human upper incisors were disinfected, cleaned, and labial side of each incisor sectioned into 3 fragments by 2 ${\times}$ 2 mm size. After sectioning, labial sides of fragments were flattened and fixed to orthodontic bracket using flowable composite resin. Specimens prepared from each tooth were attached to the labial side of upper incisors of twenty volunteers one by one and treated by three different methods: (1) untreated control (2) treated with whitening strip for 14 days (3) treated with whitening gel for 14 days. Microhardness (Microhardness tester, Zwick) of each specimen was measured at the baseline of pre-treatment, immediate after bleaching treatment, 14 days after bleaching treatment and Knoop Hardness Number was determined. Microhardness changes of experimental groups were compared. The results show that tooth whitening strip and gel used in this study does not effect the microhardness of enamel during bleaching procedure.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.541-541
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• 2013

현재 병원에서 사용하는 치아미백은 고농도의 과산화수소와 carbamide peroxide가 함유된 미백제를 이용하여 전문성을 가진 의사가 직접 시술을 하고 있다 [1]. 과산화수소의 농도가 높을수록 미백효과가 높지만 [2] 과산화수소의 농도가 지나치게 높으면 인체에 유해하다 [3,4]. 따라서, 고농도의 과산화수소가 함유된 미백제의 사용은 전문가만 시술할 수 있도록 이를 제한하고 있다. 이로 인해, 일반 가정용으로 판매되는 다양한 미백제품들은 저농도(최대6%)의 과산화수소가 함유되어 있으며 장기간 지속적으로 사용해야만 치아미백효과를 볼 수 있다. 우리는 가정에서도 보다 안전하고 단기간에 효율적으로 치아의 미백효과를 보기 위하여, 식품의약품안정청에서 규제하고 있는, carbamide peroxide (15%)와 저온 대기압 플라즈마 제트를 사용하여 미백효과를 관찰하였다. 플라즈마 제트의 유량은 200 sccm이며, 공기를 사용하였다. 미백효과를 보기 위한 대상으로는 우치(牛齒)를 사용하였으며, 플라즈마를 처리하여 미백효과를 관찰하였다. 실험 대조시료군으로는 carbamide peroxide (15%)를 처리하지 않은 우치와 처리한 우치, 그리고 carbamide peroxide (15%)를 처리한 우치에 수증기(0.2~1%)를 첨가한 다음, 이들 세가지 시료에 각각 공기 플라즈마를 조사하여 비교해보았다. 모든 실험의 플라즈마 처리시간은 최대 20분까지로 하였다. 수증기를 첨가한 이유는 활성산소의 농도를 높이기 위함이며, 이로써 탁월한 미백효과를 얻을 수 있다. 이는 활성산소와 치아의 유기질이 반응하여, 색이 진한 탄소고리 화합물을 밝은 색의 사슬구조로 바꿔주기 때문이다. 실험을 통하여 우치에 carbamide peroxide (15%)와 수증기(0.2~1%)를 처리한 경우 플라즈마의 미백효과가 탁월함을 보였다. 이때 CIE색좌표 ($L^*a^*b^*$)에서 명도도가 최대 2배 이상 높아짐을 보았다. 미백효과에 대한 측정은 측색분광기(CM-3500d)를 이용하였다.

• Journal of dental hygiene science
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• v.12 no.4
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• pp.320-328
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• 2012

The purpose of this study was to evaluate the tooth whitening and properties of an enamel surface after treatments with tooth bleaching agents that contained dicalcium phosphate dihydrate (DCPD) and hydrogen peroxide (HP). Thirty specimens were obtained from fifteen premolar and were randomly divided into three groups (n=10): 1, 3.5% HP + 0 g DCPD; 2, 3.5% HP + 0.1 g DCPD; 3. 3.5% HP + 1 g DCPD. All groups were bleached 8 hours per day for 14 days. With increasing DCPD concentration, the pH values in the agents increased, making it less acidic. However, there was no statistically significant difference (p>.05). As the concentration of DCPD was increased, the concentration of Ca and P was also increased. In all groups, after the tooth whitening, the tooth color was found to have a value of $L^*$ (p<.05). All groups showed significantly decreased enamel microhardness compared to their baseline (p<.05). The percentage microhardness loss (PML) of the group A1 and A2 were significantly lower than that of group A3. The obvious variation of morphology was observed on enamel surfaces in group A1. Following an analysis of the constituents of enamel surface after bleaching, as DCPD content was increased, the amount of Ca and P was increased. In this study, the experimental results suggest that DCPD/HP agent less demineralization changes such as the erosion morphology and hardness loss without compromising whitening efficiency.

• Journal of the Korea Convergence Society
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• v.6 no.5
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• pp.165-171
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• 2015

This in vitro study compared the effect of bleaching agent modified by the addition of $TiO_2$ catalyst converged bleaching agent. Nonvital teeth samples were assigned to four group(n=6) according to the bleaching agent: 10% carbamide peroxide(CP) bleaching agen, 10% CP with 10% $TiO_2$ catalyst, 20% CP bleaching agent and 20% CP with 20% $TiO_2$ catalyst. Changes in enamel color were evaluated on minutes 30, 60, 180, 300 and 420. It was found that 20% CP with 20% $TiO_2$ catalysis increased the whiteness and overall color value and showed significantly brightened. The teeth bleaching time was reduced with $TiO_2$ catalyst converged bleaching agent. This result will contribute to development of the teeth bleaching agent.

• 농업기술회보
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• v.49 no.4
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• pp.30-31
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• 2012

국내에 재배되는 복숭아의 품종은 다양하다. 경기도 이전지역에서만 보면, 7월 중순부터 조생종인 '용궁백도', '미백조생'이 출하되기 시작하여 본격적으로 8월 중순에 중생종인 '미백도', 8월 하순부터 만생종인 '천중도백도', 9월 초 중순부터 극만생종인 '장호원황도'가 수확된다. 그러나 본격적 복숭아 수확기인 8월 중순부터 미백도~천중도백도 사이의 단경기를 극복할 수 있는 우량품종이 절실히 요구됐다. 또한 대부분의 복숭아 품종들이 보구력이 약해서 수확, 운반 및 저장에 많은 어려움을 느끼고 있었다. 이에 따라 이재권씨는 미백도 나무에서 접목변이지로 미백도와 다른 모양의 복숭아를 발견하고 기술개발에 참여하게 되었다.

• Journal of dental hygiene science
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• v.10 no.4
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• pp.295-300
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• 2010

The aim of this study were to elucidate effects of fluoridated bleaching agents and post-treatment fluoride application on the color and microhardness of enamel surface. Twenty freshly extracted human adult molar were each sectioned into halves, the specimens divided and treated according to four experimental groups: 1, untreated controls: 2, treatment with 10% carbamide peroxide (CP) bleaching agent; 3, treatment with 10% CP containing 0.11% fluoride; 4, treatment with 10% CP followed by a 0.9% sodium fluoride gel application. Group 2-4 were compared with the baseline data. treated 8 h per day for 14 days then immersed in distilled water for 2 weeks. Changes in enamel color and microhardness were evaluated on Days 7 and 14. All the bleached enamel specimens revealed increased whiteness and overall color value. Groups 2 and 4 showed significantly decreased enamel microhardness compared to their baseline. The specimens treated with fluoridated bleaching agents showed relatively less reduction in enamel microhardness than those treated with nonfluoridated agents during the bleaching treatment. The addition of fluoride did not impede the tooth whitening. The fluoridated bleaching agents reduced the microhardness loss of enamel.

• Journal of the Korea Society of Computer and Information
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• v.28 no.10
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• pp.179-186
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• 2023

This study investigated tooth whitening preferences among college students, evaluating their knowledge, satisfaction, aesthetic criteria, and preferences, while identifying influencing factors. Using a 28-item questionnaire covering general, tooth whitening knowledge, satisfaction, aesthetic criteria, and preference questions, 175 participants surveyed from June 7th to 10th, 2022, underwent analysis. Descriptive statistics, t-tests, analysis of variance, and regression analysis were applied. Results showed tooth whitening knowledge scored 2.90 out of 5 points, satisfaction 2.97, aesthetic criteria 3.59, and preferences 3.28. Tooth whitening knowledge was higher among female and health-related major students, while satisfaction was greater among males, non-health-related majors, and those without cosmetic procedures. Aesthetic criteria were stronger in participants with higher allowances and cosmetic procedures experience. No significant tooth whitening preference differences were found based on general characteristics. Regression analysis revealed significant impact of aesthetic criteria on tooth whitening preferences (β=0.252).