• Journal of dental hygiene science
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• v.15 no.3
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• pp.377-382
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• 2015

The purpose of this study was to evaluate the validity and reliability of plaque scoring system using new Qraycam (All in One Bio, Korea) device which enables plaque score without tooth disclosing. This study measured Quigley-Hein index and plaque control record by both Qraycam and disclosing agent on 64 elderly people and checked degree of congruence between the two methods. Reliability was evaluated with the mean of measured values, kappa index and intraclass correlation coefficient statistical analysis. The analysis of the plaque scores showed a high agreement between the measured values according to the method of measurement and the measured part. The mean of plaque index of anterior labial were not significantly different according to measurement method. The kappa index was higher by Qraycam and tooth disclosing method of plaque index. Therefore, it was verified that Qraycam has sufficient reliability as screening tool for plaque scoring system.

• Journal of dental hygiene science
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• v.13 no.2
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• pp.165-173
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• 2013

The purpose of this study was to evaluate the surface change after 15% carbamide peroxide home bleaching to various restorative materials (composite resin [CR], resin modified glass ionomer [RMGI] and glass ionomer [GI]) and to observe the effect of surface condition of the materials on re-staining. Three esthetic restorative materials (Filtek Z250, 3M, USA; Fuji II LC, GC, Japan; Fuji II, GC, Japan) were used in this study. Twenty specimens per material group were made and divided into two groups (bleached and control). The specimens were immersed in coffee after applying bleaching agent. The color change and surface roughness were measured before and after bleaching and after immersion in coffee. The data were analyzed with SPSS 18.0. The results were as follows: 1. The color of all experiment groups was significantly changed after bleaching (p<0.05). RMGI was the greatest value of ${\Delta}E^*$ and ${\Delta}L^*$. GI and CR groups were in ordering (p<0.05). The ${\Delta}a^*$ value was decreased GI, RMGI and CR. RMGI was only significantly decreased in ${\Delta}b^*$ value (p<0.05). 2. The surface roughness before and after bleaching was significantly different on CR, RMGI and GI (p<0.05). 3. After staining with coffee, the value of ${\Delta}E^*$ was increased in GI, RMGI and CR, furthermore GI and RMGI showed significant difference in the bleaching groups (p<0.05). The ${\Delta}L^*$ value of GI and RMGI was significantly decreased. 4. The change of surface roughness after staining was not significantly different in all groups (p>0.05). The maintenance of color stability in esthetic restorations is one of the most important properties. Tooth whitening is for the aesthetic. Therefore, dental professionals should notice to patients about re-staining after tooth whitening. They should give an instruction that how to prevent and which kinds of agents could be stained.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.176-182
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• 2018

One of the most important factor of esthetic prosthesis is the color of the teeth. Zirconia is produced in the process of design, milling, coloring, drying, and sintering. The effect of the drying degree of zirconia colorant on the color tone is examined. For the experiment, a total of 45 zirconia specimens(15 for each) were fabricated by using cad/cam system. The zirconia specimens(L block(LAZOR), Z block(Zircos-E block posterior), A block(AlphaZ)) were then subjected to zirconia sintering in accordance with the manufacturer's instructions, using a chemical coloring agent to Non-drying(0sec), intermediate (10sec), and completely dried (10min) temperature holding times. The color tone was measured using a spectrophotometer. The results were analyzed with a One-way analysis of variance and the Tukey post-hoc test (${\alpha}=.05$) The $L^*$ values of L, A specimens, $a^*$ values of A specimens, and $b^*$ values of Z specimens were not statistically different according to the degree of drying (p>0.05), While the $L^*$ value of Z specimen, $a^*$ value of L, Z specimen, $b^*$ values of L, A specimens were statistically different according to the degree of drying(p <0.05). In conclusion, the drying of zirconia colourants improves zirconia brightness and increases the optical properties of the enamel.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.30 no.2
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• pp.53-58
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• 2021

The attractiveness of the gingiva is determined by its color, shape, and the shape and location of the boundary between the teeth and the gingival tissue. The standards beauty, balance, and health of the gingiva are all different, but the general public would agree that a coral pink gingiva is more beautiful than black or brown gingiva. Hence, one would be able to smile more confidently in public if he or she receives a gingival pigmentation removal surgery that changes the color of black or brown gums to a beautiful pink color with relative simplicity. The color of one's gingiva varies from pale pink to deep bluish purple, depending on many health components. The most prominent among these include the vascular supply, epithelial thickness, the degree of keratinization, and the presence of pigment in the epithelium. Melanin, carotene, reduced hemoglobulin, and oxyhemoglobulin are the main pigments contributing to the normal color of the oral mucosa. The health of one's gingival tissue are essential for an attractive smile. Excessive melanin deposits in the basal and early basal layers of the epithelium stored in the form of melanosomes frequently cause pigmentation. Although there are many different procedures to remove this pigmentation, the it was removed using the Er;YSGG laser. It is my wish that, through this case study, many people

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.2
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• pp.210-216
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• 2002

Air abrasion technology can prepare enamel and dentin for bonding, similar to etching by acidic gels and solutions. Longer treatment can excavate pit and fissures, preparing the tooth for immediate placement of bonded resin materials. Although not appropriate for every clinical situation, the air abrasive technology minimizes heat, vibration and bone-conducted noise associated with conventional means of caries removal since the cutting is accomplished by air pressure. Also, patients treated with the air-abrasion technology rarely request anesthesia. Air abrasion technology was more effective in treating early carious lesions and stains compared to lesions where caries had already progressed to produce soft dentin and the strong air stream and noise caused by the evacuation system was a major discomfort to pediatric patients, and the experience and skillfulness of clinician should be required for accurate and proper tooth preparation.

• The korean journal of orthodontics
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• v.26 no.1 s.54
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• pp.17-32
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• 1996

It is important to understand the operating mechanism and force system of fixed appliance that most effective for individual tooth movement in various orthodontic appliances. The archwire system of fixed appliance is devided into 3 types, which is continuous arch, segmented arch and sectional arch. The last two types have longer interbracket distance and simple force operating points, so it is easy to control force system by operator. But the continuous arch has shorter interbracket distance and various bracket geometry, so it is hard to control and anaylze the force system. The purpose of this study was three dimentional force and moment analysis of continuous arch system by finite element method, which is similar situation to three dimentional elastic beam in structural engineering. Several sample form of various bracket geometry and artificial lower crowding typodont made by author were constructed, analyzed and compared each other. The results were as follows : 1. The force magnitude is linear proportional to the degree of displacement or tilting of the bracket. 2. The force magnitude is inversely non-linear proportional to the interbracket distance. 3. In three dimensional typodont model, while the force can be compared with that of the sample form in the area where adjacent bracket geometry is simple, the force is much more than the expected value in the area where adjacent bracket geometry is complex.

• Journal of dental hygiene science
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• v.13 no.2
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• pp.203-212
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• 2013

The tooth morphology and qualitative mineral contents on enamel surface using energy dispersive X-ray spectroscopy, (EDX) were examined in the white-toothed shrew (genus Crocidura ) Crocidura lasiura and C. suaveolens and the red-toothed shrew (genus Sorex) Sorex caecutiens. In the case of C. lasiura and C. suaveolens, dental formula was found I 3/1 C1/1 P1/1 M3/3=28. The upper 1st and 2nd molars had an unequal W-shape formed by 5 cusps on the crown. The 3rd molar was found one-third the size of those of 1st and 2nd molars. The upper 1st incisor had two different sized hook-shapes and the lower 1st incisor was even. In the case of S. caecutiens, dental formula was found to be I3/1 C1/1 P3/1 M3/3=32. The upper 1st and 2nd molars had an equal W-shape on crown. The upper 3rd molar was half the size of those of the other molars. The upper 1st incisor possessed two similar sized hook-shapes and the lower 1st incisor had an uneven and serrated form. A comparison with the dental and cranial measurements revealed C. lasiura to be the largest of the three species (p<0.001) and C. suaveolens and S. caecutiens were similar in size (p>0.05). A qualitative analysis of mineral contents on enamel surface of the lower 1st incisor and lower 1st molar using EDX revealed C, O, P, Ca and Cu in all specimens and Pb was detected in several enamel specimens. No significant differences in the mineral contents (% weight) were observed among the three species (p>0.05). Fe was only detected on enamel surface of S. caecutiens with red pigmented teeth. Therefore, Fe is responsible for the red tip of the teeth. These results suggest that tooth morphological characteristics including the color of the tooth tip might be used as the key classifying species belonging to Crocidura and Sorex.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.3
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• pp.400-405
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• 2004

Biliary atresia is defined as a complete obstruction of bile flow owing to destruction or absence of all or part of the extrahepatic bile ducts. This disease is occurring in approximately 1:10,000 live births and moderate predominance of female is noted. The etiology of biliary atresia remained unsolved. The signs and symptoms are hyperbilirubinemla, jaundice, clay-colored stools, steatorrhea, dark yellow urine and hepatomegaly. Currently biliary atresia is best managed by hepatic portoenterostomy with or without liver transplantation. Biliary atresia patients with these cases showed staining of the teeth. The stains ranged in color from yellowish-brown to deep green. Enamel hypoplasia was all erupted teeth present. Patients had poor oral hygiene and rampant caries.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.3
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• pp.345-351
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• 2010

The purpose of this study is to compare microleakage and penetration depths of sealants applied in carious and sound fissures. Extracted premolars(n=80) were divided into 4 groups according to caries status. 1; sound, 2; stained, 3; initial caries, 4; enamel caries. Sealants were applied to the occlusal groove as per manufacturers' instructions, and specimens were thermocycled, stained, sectioned, and examined for microleakage and penetration ability. The results of the present study are as follow: 1. It showed significantly higher microleakage scores in group I than group Two, Three, Four(p<0.05), but no significant difference was found between group Two, Three, and IV(p>0.05). 2. It showed significantly higher penetration scores in group Four (p<0.05), followed by group One, Two, Three, but no significant difference was found between group One, Two, and Three(p>0.05). Based on the results of present study, when the borders of the fissure sealant are on carious enamel, a significantly higher microleakage must be expected. It is considered that depth of enamel caries in the fissure should be taken into account when applying a fissure sealant.

• The Korean Chronic Disease News
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• no.322
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• pp.1-18
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• 2007

은퇴의사 보건소 봉사체계 도입/내년부터 병원 등 전면파업 금지/노인요양병원 30곳 종합실사/한국인 혈당 기준 대폭 강화/흡연이 40대 발기부전 직접 원인/노인 성병 감염자 대책 절실/복강경 대장수술 97%가 대장암/이화의료원, 여성전문대학병원 재도약/베트남에 한양대 류마마티스 센타 설립/김안과, 범태평양 안과병원 네트워크 구축/약제비절감 의사에 인센티브 제공/의약품 표준코드 시행 1년 유예 요청/전 국민 살빼기 캠페인/자궁경부암 백신, 45세까지 접종 확대/제약협회와 긴밀한 관계 유지/만성폐쇄성폐질환(COPD) 환자 급증/흡연, 음주가 대사증후군 2배 높여/골다공증에 대한 이해 여전히 부족/표준체중 성인도 '복부비만' 주의/녹차, 충치 예방과 치아 착색의 양면성/마음을 여는 Heart행정 실현-충주시보건소/'열심, 합심, 양심', 三心행정 지향/만성질환관리의 정책적 추진 방향/