• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
• /
• pp.250.2-250.2
• /
• 2014

Currently, teeth whitening method which is applicable to dental surgery is that physician expertises give medical treatment to teeth directly dealed with a high concentration of hydrogen peroxide and carbamide peroxide. If hydrogen peroxide concentration is too high for treatment of maximized teeth whitening effect [1], it is harmful to the human body [2]. To the maximum effective and no harmful teeth whitening effect in a short period of time at home, we have observed the whitening effect using carbamide peroxide (15%) and a low-temperature atmospheric pressure plasma jet which is regulated by the Food and Drug Administration. The gas supplied conditions of the non-thermal atmospheric pressure plasma jet was with the humidified (0.6%) gas in nitrogen or air at gas flow rate of 1000 sccm. Also, the measurement of chemical species from the jet was carried out using the optical emission spectroscopy (OES), the evidence of increased reactive oxygen species compared to non-humidified plasma jet. We have found that the whitening effect of the plasma is very excellent through this experiment, when bovine teeth are treated in carbamide peroxide (15%) and water vapor (0.2 to 1%). The brightness of whitening teeth was increased up to 2 times longer in the CIE chromaticity coordinates. The colorimetric spectrometer (CM-3500d) can measure color degree of whitening effect.

• 치위생과학회지
• /
• 제21권3호
• /
• pp.178-184
• /
• 2021

Background: As the importance of the esthetic function of teeth increases, the use of esthetic restoration materials and whitening treatment are increasing. The purpose of this study was to investigate the color change of esthetic restoration materials upon using staining and whitening toothpaste. Methods: Light curing (LC) packable composite resin, LC flowable resin, LC glass ionomer (GI), and self-curing GI specimens were colored in coffee or curry for three hours a day for seven days. After that, regular toothpaste, whitening toothpaste containing hydrogen peroxide, and whitening toothpaste containing activated charcoal were applied for three minutes three times a day for two weeks. Luminosity (L), chromaticity a (a), and chromaticity b (b) were measured using a spectrophotometer once a week. Results: In the coffee-colored group, the change in L^2*a^2*b² (E²) with time was significant (p=0.004), there was no difference for different toothpaste types (p=0.646), and there was significant difference (p<0.001) for different esthetic restorative materials. The change of E² in the curry-colored group was significant only for different esthetic restorative materials (p<0.001). In the coffee-colored group, the L, a, and b values of the light-curing GI showed greater change than other materials after staining and one week after whitening, turning dark, red, and yellow. In the curry-colored group, L did not differ for different materials and times, and a and b showed the greatest difference in light-curing GI after staining and one and two weeks after whitening. Conclusion: The use of whitening toothpaste for two weeks was not different from the use of general toothpaste in the removal of staining or whitening. Since light-curing GI is the most vulnerable to coloration, it is recommended that coloring by food chromogen should be explained in advance, before using light-curing GI for teeth restoration.

• 한국치위생학회지
• /
• 제13권4호
• /
• pp.605-613
• /
• 2013

Objectives : The purpose of this study is to establish guideline for tooth whitening by investigating the awareness towards tooth whitening. Methods : The subjects were recruited in Seoul and Gyeonggi-do from June to August, 2011. A total of self-reported 395 questionnaire data were analyzed except for 5 incomplete answers. Results : 1. Smoking and coffee had no significant influence on the intention to whiten the tooth according to gender(p<0.001), age(p<0.001) and marital status(p<0.001). 2. Seventy persons (64.8%) tried to whiten tooth for color change. Half of the respondents (50.0%) bleached teeth by themselves. Of 295 persons, 66 persons (61.1%) were satisfied with self-whitening of teeth. Conclusions : Majority of the respondents wanted to whiten their teeth and they tried whiten by themselves because the whitening procedure was easy to do. It is necessary to establish the guideline for whitening teeth for safety.

• Journal of Biosystems Engineering
• /
• 제12권2호
• /
• pp.28-37
• /
• 1987

Operation of rice whiteners has been depending on operator's experience only and very limitted data are available for operational criteria of rice whiteners in Korea. With developments of new rice varieties and with a tendency of automation of machine operations for precision control, operational criteria depending on physical characteristics of rice grains arc required for an improvement of milled rice recovery and the performance of rice whitening systems. An experimental study was conducted to identify operational criteria of a rice whitening system consisted with an abrasive-aerated whitener developed newly and a frictional-aerated whitener being used commercially. Further, comparisons were made between the performance of the rice whitening system adopted for this study and a commercial system used in small scale milling plants. Results of this study are summarized as follows: 1. Total number of passes necessary for the final white rice in the combined whitening system depended exclusively on the counter pressure level of the frictional whitener successive to the abrasive whitener. 2. The counter pressure required for whitening Japonica type rice variety (Akibare) was higher by about 1.6 times than that for Japonica type (Pung-san), when other conditions were kept at the same. 3. Radial pressure in the whitening chamber of the frictional whitener should be maintained between 1.5 to $2.1kg/cm^2$ for the completion of whitening within 5 to 3 passes regardless of rice varieties. Hence, it was found that the radial pressure in the whitening chamber could be used as an operational criteria to control the counter pressure level. 4. The following regression equation was found between radial pressure($R_p$) in whitening chamber and electric power consumption of the whitening system: $$EPC=-0.545\;R^2_p+1.277\;R_p+0.874[KWH/100kg]$$ 5. The following multiple regression equation was found among radial pressure ($R_p$), counter pressure ($C_p$), and bioyield point ($B_i$), length (L) and width (W) of brown rice. $$R_p/(B_i/W^2)=0.547\{C_p/(B_i/W^2)\}^{0.365}(L/W)^{0.120}(R^2=0.9897)$$ 6. The milled rice recovery and machine efficiency (kg/KWH) from the combined whitening system were higher by about 2.0% point and by 15 to 27% point than those from the conventional system, respectively.

• 한국환경생태학회지
• /
• 제31권6호
• /
• pp.529-536
• /
• 2017

이 연구는 제주연안 해역에서 갯녹음의 확산동향과 기후변화로 인한 동계 수온변화(수온상승)가 갯녹음 확산에 미치는 영향을 알아보고 갯녹음 원인생물인 무절석회조류의 번식과 생장을 파악하기 위해 연구되었다. 제주연안의 갯녹음 발생면적은 1998년에는 2,931ha였으나, 2003년에는 4,541ha로 증가하였다. 발생해역도 1998년은 제주도 남부해역에서 주로 발생했으나, 2003년에는 조천읍, 구좌읍을 제외한 제주도 전역으로 확산되었다. 1992년부터 2004년까지 관측된 2월 평균수온은 갯녹음 해역 $15.1^{\circ}C$, 해중림 해역 $13.9^{\circ}C$로 갯녹음 해역이 $1.2^{\circ}C$가 높게 나타나 두 해역 간 뚜렷한 차이를 보였으나, 8월 수온은 두 해역 간 차이가 없었다. 수온의 장기변동(37년)에서도 갯녹음 해역이 평균 $15.3^{\circ}C$인데 비하여 해중림 해역은 평균 $14.1^{\circ}C$로 갯녹음 해역이 해중림 해역보다 $1.2^{\circ}C$가 높게 나타났다. 연간 수온 증가 값은 갯녹음 해역이 매년 $0.038^{\circ}C$씩 증가하고 있는 반면, 해중림 해역은 $0.024^{\circ}C$씩 증가하여 장기 수온변동은 갯녹음 해역이 해중림 해역보다 높았다. 이와 같이 기후변화로 인한 지속적인 동계 수온상승은 제주도 갯녹음을 확대시키고 있음을 시사하고 있다.

• 국제지역연구
• /
• 제21권2호
• /
• pp.121-141
• /
• 2017

세계 미백화장품시장은 복합된 기능을 포함한'복합기능성화장품'시장으로 빠르게 넘어가고 있다. 또한 고기능성화장품시장인 코스메슈티컬시장은 복합기능성화장품 시장과 함께 성장하고 있다. 더불어 복합기능성화장품 시장에서 미백기능을 포함한 천연화장품 시장은 전세계에서 성장하고 있다. 전세계 기능성화장품 유통채널은 '미용과 디지털(Beauty and Digital)'을 통한 디지털 커뮤니케이션(digital communication)이다. 글로벌 기업들은 브랜드와 소비자 사이에서 새로운 공간에 관계를 추가하고 있다. 그렇기에 전세계적인 미백화장품 유통 채널의 변화현상은 기존과 다른 공간에서 고객과 소통될 수 있어야 한다는 중요성을 시사를 할 것이다. 국내 미백화장품시장은 2015년 기준 연평균성장률 -3.61%로 감소하고 있다. 반면에 복합유형시장은 연평균성장률 33.28%로 지속적인 성장을 나타내고 있다. 국내 미백화장품시장은 2008년 이후로 기존의 방문판매 중심의 유통채널에서 변화되었다. 특히 온라인채널은 오프라인채널 대비 약1/6 수준이지만, 2014년 기준으로 온라인쇼핑의 전년대비증가율이 27.1%를 나타냈다. 향후에는 오프라인의 판매비중과 비슷해지거나 뛰어넘을 것으로 예측된다. 미백화장품의 유통채널은 변화하고 있고, 온라인 유통채널은 성장하고 있어, 국내 기업들은 새로운 미백화장품 유통채널과 기존의 오프라인 채널을 동시에 공략하는 전략이 필요할 것으로 사료된다. 신규기업의 미백화장품시장 진출 시, 기존의 미백화장품시장보다 복합기능성화장품 내의 천연화장품으로의 진입을 고려해야 할 것으로 판단된다. 국내 미백화장품 시장 경쟁력을 확보하기 위해서는 브랜드 차별성을 확보하거나 유통채널의 변화를 추구하여 기업과 고객이 새로운 공간에서 커뮤나케이션을 구축할 수 있는 진출방안을 모색할 필요가 있다.

• 구강회복응용과학지
• /
• 제34권3호
• /
• pp.175-185
• /
• 2018

목적: 미백젤의 효과 증대 및 치은 자극의 최소화를 위해 wrap을 사용하는 자가 도포 치아 미백제의 임상적 효능과 안전성을 평가하는 것이다. 연구 재료 및 방법: 90명의 피험자를 대조군과 2.8%, 3.0%의 과산화수소가 포함된 미백젤을 사용하는 두 개의 실험군으로 각각 30명씩 무작위 배정하였다. 그들은 상악 4전치 부위에 하루 1번 30분씩 2주간 미백젤과 wrap을 사용하였다. VITA shade guide와 ShadeEye $NCC^{(R)}$를 이용하여 치아 색조 측정을 하였고, 부작용은 인터뷰와 구내 검사로 조사하였다. 효능과 안전성 평가를 위해 통계 처리 하였다. 결과: 비타 색조 기준표에 의한 평가에서는 미백 성분이 들어있는 실험군에서 대조군과 비교시 유의한 미백 효과를 보였다. 측색기를 이용한 평가에서는 3.0% 실험군이 대조군과 2.8% 실험군에 비해 유의한 미백 효과를 보였다(P < 0.05). 경미한 부작용의 호소가 일부 있었으나 모든 군에서 치은 자극에 대한 이상증상을 보이지 않았다. 결론: Wrap을 사용한 자가 도포 미백젤은 과산화수소의 농도가 2.8%에서 3.0%로 높아질수록 그 효과가 증가되며 유의하게 심각한 부작용이 관찰되지 않아 유용한 자가 미백 치료제로 활용될 수 있다.

• Elastomers and Composites
• /
• 제47권3호
• /
• pp.210-215
• /
• 2012

무기첨가제의 조성이 다른 EPDM 복합체를 준비하여 $90^{\circ}C$ 공기와 수돗물에서 각각 7일간 노화시켜 백화현상을 관찰하였다. 공기 중에서 노화시킨 시험편들은 모두 백화가 발생하지 않았으나, 수돗물에서 노화시킨 시험편들 중 스테아린산이 함유된 시험편들은 백화가 심하게 발생하였다. 무기첨가제의 조성에 따른 백화 현상의 차이는 없었다. 백화 물질을 가스 크로마토그래피/질량분석법(GC/MS), 영상 분석(image analysis), 에너지 분산 X-선 분광법(EDX), 감쇠 전반사-후리에 변환 적외선 분광법(ATR-FTIR)을 이용하여 분석하였다. 백화 물질은 스테아린산의 금속염이라는 것을 확인하였다. 스테아린산의 금속염은 수돗물에 존재하는 금속 이온과 시험편 내에 존재하는 스테아린산과의 반응에 의해 형성된다.

• 한국치위생학회지
• /
• 제15권2호
• /
• pp.325-332
• /
• 2015

Objectives: The purpose of this study was to investigate tooth whitening maintenance efficacy of several dentifrices containing effective ingredients for tooth whitening. Methods: Hydroxyapatite specimens(HAPs) staining was done by using modified Stookey's methods. HAPs were treated with 2.9% hydrogen peroxide containing strip for whitening, and were shaken with several dentifrice slurry(dentifrice 1 : artificial saliva 2) for 30 minutes. The HAPs were finally dipped in staining solution for an hour. Shaking and dipping were repeated 4 times and lightness values were measured by colorimeter at each step. In clinical test, test 4 dentifrice and control dentifrice were evaluated by 21 subjects for 2 months after receiving institutional review board(IRB) approval. Organoleptic(vita shade guide) and instrumental(SHADEEYE-NCC) evaluation were performed for whiteness change of teeth. Statistical analysis was performed using repeated measures ANOVA, Tukey's post hoc test and ${\chi}^2$-test(p<0.05). Results: All dentifrices showed statistical significance in comparison with control dentifrice containing sodium fluoride and test 4 dentifrice containing sodium pyrophosphate, sodium metaphosphate, candelilla wax, and sodium fluoride showed statistical significance in comparison with other dentifrices by inhibiting staining in vitro(p<0.05). In clinical test, test 4 dentifrice showed better effects than control dentifrice in organoleptic and instrumental evaluation in tooth whitening maintenance efficacy(p<0.05). The awareness toward tooth whitening maintenance efficacy for 2 months use showed that test 4 dentifrice was much better than control dentifrice, but did not show statistically significant(p>0.05). Conclusions: Dentifrice containing sodium pyrophosphate, sodium metaphosphate, candelilla wax and sodium fluoride was more effective in keeping teeth white.

• Restorative Dentistry and Endodontics
• /
• 제44권1호
• /
• pp.6.1-6.11
• /
• 2019

Objectives: The aim of the present study was to evaluate the effect of whitening mouth rinses alone and in combination with conventional whitening treatments on color, microhardness, and surface roughness changes in enamel specimens. Materials and Methods: A total of 108 enamel specimens were collected from human third molars and divided into 9 groups (n = 12): 38% hydrogen peroxide (HP), 10% carbamide peroxide (CP), 38% HP + Listerine Whitening (LW), 10% CP + LW, 38% HP + Colgate Plax Whitening (CPW), 10% CP + CPW, LW, CPW, and the control group (CG). The initial color of the specimens was measured, followed by microhardness and roughness tests. Next, the samples were bleached, and their color, microhardness, and roughness were assessed. Data were analyzed through 2-way analysis of variance (ANOVA; microhardness and roughness) and 1-way ANOVA (color change), followed by the Tukey post hoc test. The Dunnett test was used to compare the roughness and microhardness data of the CG to those of the treated groups. Results: Statistically significant color change was observed in all groups compared to the CG. All groups, except the LW group, showed statistically significant decreases in microhardness. Roughness showed a statistically significant increase after the treatments, except for the 38% HP group. Conclusions: Whitening mouth rinses led to a whitening effect when they were used after conventional treatments; however, this process caused major changes on the surface of the enamel specimens.