• Restorative Dentistry and Endodontics
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• v.24 no.2
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• pp.364-371
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• 1999

본 연구는 테트라싸이클린에 의해 변색된 백서 치아에 대한 3 종 표백제의 표백효과를 비교하고 표백제의 침투 깊이 (법랑질 두께)에 따른 표백효과의 차이를 판별하기 위해 시행되었다. 30 마리의 웅성 백서에 매일 2주 동안 테트라싸이클린 용액을 복강내 주입하였다. 디스크 형태의 32개 백서 치아 표본을 16 시간 동안 자외선으로 조사하여 변색을 야기시켰다. 대조군은 생리 식염수에 보관하였으며 실험군은 3종 표백제(Opalescence, Rembrandt, NiteWhite)에 하루 5회씩 2주간 노출시켰다. 치아 색상을 표백전, 표백 1일, 3일, 5일, 7일, 9일, 11일, 및 14일에 각기 기록하여 치아내 변색부와 정상 색상간의 색상차 (${\Delta}$E)를 판독하였다; 대조군 - 9.78, 9.17, 9.36, 9.65, 9.40, 9.99, 10.57, 11.36; Opalescence - 10.08, 7.63, 6.72, 6.04, 5.10, 4.87, 4.89, 4.27; Rembrandt -9.83, 11.27, 9.55, 8.36, 7.75, 6.94, 7.11, 7.04; NiteWhite - 10.44, 9.92, 7.58, 6.80, 5.45, 5.05, 4.73, 4.01. 표백된 모든 치아들의 색상이 밝아졌다. (p<.01) 테트라싸이클린이 주입된 56개 백서 치아를 3 일간 자외선에 조사한 다음, 3가지 유형의 표백제 침투깊이를 설정하였다. 설측 상아질과 순측 법랑질을 통한 침투 (DN), 순측 법랑질만을 통한 침투 (RE), 1.0 mm 두께의 사람 법랑질로 피개된 순측 법랑질을 통한 침투 (HE). 표본들을 Opalescence로 하루 5회씩 1주일 및 4 주간 표백한 후 횡단하여 치아 색상을 측정하였다. 표백되지 않은 치아들을 대조군으로 이용하였다. 치아내 변색부와 정상 색상간의 색상차 (${\Delta}$E)는 다음과 같았다. 대조군 - 11.67; 1주 DN 군 - 13.55; 1주 RE군 - 12.80; 1 주 HE군 - 12.07; 4주 DN군 - 7.48; 4주 RE군 - 7.50; 4주 HE군 - 11.69. 4주 DN군과 4주 RE군의 색상 변화가 가장 크게 나타났다.(p<.01)

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.11a
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• pp.305-308
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• 2020

임플란트 시술 수요가 늘고 시장이 성장하면서 관련 기술도 발전하고 있다. 특히 기능성과 심미성 향상을 위해 많은 기술이 연구되고 있다. 이 중 심미성에 있어 주변 치아와의 색 유사도가 높은 임플란트를 제작하는 것이 주요 연구 중 하나이다. 본 논문에서는 심미성 높은 임플란트 제작을 위해, 다음과 같은 임플란트 표본 추천 시스템을 제안한다. 휴대 조명 장치와 의료용 치아 패치를 사용한 색 보정으로 촬영 환경 차이를 최소화하여 치아의 정확한 색을 추출한다. Mask R-CNN 모델을 통해 보정된 영상에서 치아를 검출하고, 군집화를 통해 색상 단위로 치아 영역을 구분한다. 치아의 영역별 색상과 임플란트 표본 사이의 색상 거리를 계산하여 유사한 표본들을 추천한다. 위 시스템을 통해 사용자는 주변 환경에 영향을 받지 않고, 치아의 색을 정확히 분석하여 이를 임플란트 표본과 비교할 수 있게 된다.

• Restorative Dentistry and Endodontics
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• v.33 no.4
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• pp.352-368
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• 2008

This study was done to evaluate the reliability of the digital color analysis system (ShadeScan, CYNOVAD, Montreal. Canada) for dentistry. Sixteen tooth models were made by injecting the A2 shade chemical cured resin for temporary crown into the impression acquired from 16 adults. Surfaces of the model teeth were polished with resin polishing cloth. The window of the ShadeScan handpiece was placed on the labial surface of tooth and tooth images were captured, and each tooth shade was analyzed with the ShadeScan software. Captured images were selected in groups, and compared one another. Two models were selected to evaluate repeatability of ShadeScan, and shade analysis was performed 10 times for each tooth. And, to ascertain the color difference of same shade code analyzed by ShadeScan, CIE $L^*a^*b^*$values of shade guide of Gradia Direct (GC, Tokyo, Japan) were measured on the white and black background using the Spectrolino (GretagMacbeth, USA), and Shade map of each shade guide was captured using the ShadeScan. There were no teeth that were analyzed as A2 shade and unique shade. And shade mapping analyses of the same tooth revealed similar shade and distribution except incisal third. Color difference (${\Delta}E^*$) among the Shade map which analyzed as same shade by ShadeScan were above 3. Within the limits of this study, digital color analysis instrument for dentistry has relatively high repeatability, but has controversial in accuracy.

• Restorative Dentistry and Endodontics
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• v.30 no.3
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• pp.170-177
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• 2005

This study was conducted in order to assess whether the form of the shade guide affects in deciding the color of the teeth using the shade guide Eight shade light cured composite resins (Esthet-X, Dentsply, Milford, USA) were used in this study. Shade guides including the model of maxillary central incisors, teeth-form shade guide, doughnut form shade guide, and shade guide with perforated gray shield were prepared with eight shade composite resins and provided the codes randomly After arranging the models of teeth, 19 dentists working at the clinic of the Dentistry of Chonnam University Hospital and 65 students of college of dentistry, Chonnnam University selected the shade guides corresponding to the color of each tooth on the gray board under the D$_{65}$ standard illuminant. Bl shade showed highest accuracy of about 95% among all shade guides of 3 forms applied to the test and regardless of observer, tooth form shade guide showed the highest accuracy (p < 0.05) , and the doughnut form showed the lowest accuracy (p < 0.05). At the time of deciding on the color of the teeth using the shade guides as a result of above, the forms of the shade guides can affect the accuracy, and it suggests that the development of the diversified forms of shade guides, which may obtain more accurate results, is required.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.1
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• pp.32-40
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• 2018

The aim of this study was to determine the efficacy of a 3 tone plaque disclosing gel in assessing the risk of caries related to the population of Streptococcus mutans, Streptococcus sobrinus, and Lactobacillus spp. quantified using a quantitative real-time polymerase chain reaction (qRT-PCR). 15 healthy children of ages 9 - 12 years were randomly examined. The 3 tone plaque disclosing gel was applied on teeth surfaces, which changed the color to pink or red, blue or purple and light blue. Plaque was divided into 3 groups based on staining. Genomic DNA from each sample was subjected to a qRT-PCR assay for quantitative detection of target bacteria. The Kruskal-Wallis test was conducted for correlation between the color of plaque and the number of bacterial species. The levels of S. mutans, S. sobrinus, and Lactobacillus spp. were significantly different in the plaque samples of the 3 groups (p < 0.05). The proportion of S. sobrinus to S. mutans showed correlation to the color of plaque. The different color-dyed plaque was related to the number of acidogenic bacteria. The 3 tone plaque disclosing gel could be used as one of the indicators to assess the clinical risk of caries associated with the population of S. mutans, S. sobrinus, and Lactobacillus spp.

• Restorative Dentistry and Endodontics
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• v.34 no.4
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• pp.309-323
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• 2009

In this study we evaluated the influence of both the thickness of residual enamel and the color of the composite resins applied to lingual surface on the labial surface color. Background plates were made by randomly (A1, A2, A6D, B1, B2, B3, C1, C2, C6D) selected colors of Filtek Supreme (3M ESPE, St. Paul, U.S.A.) composite resin. Crown portion of 9 maxillary central incisors were cut off and embedded with acrylic resin except labial surface. Samples of average thickness of 2.2 mm were obtained after cutting it in a thickness of 2.5 mm from the labial surface and sandpaper polish. The shade of composite resin background was measured using Spectrophotometer ($Spectrolino^{(R)}$, GretagMacbeth, Regensdorf, Switzerland). And CIE $L^{\ast}a^{\ast}b^{\ast}$value of 2.2 mm thickness tooth samples were measured on the 9 composite resin backgrounds. And then, the cutting side of tooth samples was ground to the extent of 1.9 mm, 1.6 mm, 1.3 mm, 1.0 mm and placed on composite resin backgrounds and measured $L^{\ast}a^{\ast}b^{\ast}$values with the same method. In all samples, $L^{\ast}$value and $b^{\ast}$value seemed to have a tendency of decreasing as thickness of tooth sample becomes thinner regardless of background colors (p < 0.05). But, $a^{\ast}$value didn't show the significant differences depending on the thickness.

• Proceedings of the KACD Conference
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• 2004.05a
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• pp.333-333
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• 2004

복합 레진을 이용한 심미 수복 시 접하게되는 어려움 중의 하나는 한정된 색상과 일정한 광학적 특성을 가진 복합 레진을 이용하여 각각 서로 다른 광학적 특성을 보이는 다양한 치아들의 색조를 재현하는 것이다. Shade matching을 시행하는 첫 과정부터 술자의 시각적 판단에 의존해야하고 판단에 사용하는 shade guide들도 이미 제공되고 있는 한정된 색상만 비색이 가능하기 때문에 shade guide에 존재하지 않은 색은 술자의 경험과 추측에 의해 결정되어 진다. 최근 컴퓨터나 측색기를 치과 영역에 도입하여 치아의 색을 측정하고자하는 시도가 계속되고 있다. 하지만 이러한 기기를 이용한 측색의 결과도 다양한 인자들의 영향을 받게되며, 비록 인간의 눈을 통해 이루어지는 비색보다는 일정한 결과를 나타낸다 하더라도 현재 치과계에서 사용하는 색상 표현 방법으로는 이렇게 기기를 이용해 측정된 결과값을 활용할 수 없게되는 문제점을 지닌다.(중략)

• Restorative Dentistry and Endodontics
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• v.25 no.2
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• pp.254-261
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• 2000

본 연구에서는 35개의 구치부 2급 와동에 고밀도 구치부 복합레진(Surefil, Caulk, U.S.A.)을 수복하였다. 단일 충전군은 18개 치아의 인접면 와동을 한꺼번에 충전한 후 광중합하였고 분할 충전군은 17개 치아의 인접면 와동을 두 층으로 나누어 충전 및 광중합하였다. 6개월 후의 임상검사 결과 다음과 같은 결론을 얻었다. 1. 기초검사에서 단일 충전군과 분할 충전군 모두 색상조화도(Color match)를 제외한 다른 검사 항목들에서 Alfa로 나타났다. 2. 단일 충전군은 6개월 후 모든 검사(색상 조화도 제외)에서 인접면 접촉도(Proximal contact), 변연부 변색(Marginal discoloration), 술후 과민증(Postoperative sensitivity) 검사에서 소수의 치아가 Bravo, Charlie로 나타났으나 기초 검사와 3개월 후 검사 사이에 통계적으로 유의한 차이는 보이지 않았다. 3. 분할 충전군은 6개월 후 시행된 모든 검사(색상 조화도 제외)에서 인접면 접촉도(Proximal contact), 술후 과민증(Postoperative sensitivity) 검사에서 소수의 치아가 Bravo, Charlie로 나타났으나 기초 검사와 6개월후 검시 사이에 통계적으로 유의한 차이는 보이지 않았다. 4. 모든 검사항목에서 단일 충전군과 분할 충전군을 비교한 결과 통계적으로 유의한 차이는 보이지 않았다. 따라서 고밀도 구치부 복합레진(Surefil, Caulk, U.S.A)은 색상 재현의 어려움을 제외하고는 여러 평가에서 우수하게 나타났으므로 본 연구 결과를 기준으로 보면 이전 복합레진의 단점이 보완되어 구치부 2급 와동에 적절하게 사용될 수 있다고 사료되며 단일 충전군과 분할 충전군 사이에 통계적으로 유의한 차이를 보이지 않으므로 시술 시간을 좀 더 단축시킬 수 있을 것으로 사료된다.

• Restorative Dentistry and Endodontics
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• v.32 no.5
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• pp.411-418
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• 2007

The most scientific and reliable method for deciding the tooth color is the instrumental measurement. However, such color measuring instrument shows the difference of the measuring value according to the diversified measuring condition. This study was conducted to evaluate what effect of the labial surface irregularity of the tooth to the result of the color measured by spectrometer. 11 models of the teeth were made by injecting the A2 shade Luxatemp Automix Plus (DMG, Germany) into the impression acquired from 11 adults. Standard disk samples (15 mm diameter, 7 mm thickness) were made with same material. CIE $L^*a^*b^*$ value was measured at the incisal, central, and gingival area of the central incisor, lateral incisor, canine and first premolar using Specbos 2100 (JETI, Germany) spectrometer. Color difference was calculated between labial surface and standard samples. Among all models of the teeth, $L^*\;and\;b^*$ value showed the reducing tendency as they go toward the gingival area, but $a^*$ value showed the increasing tendency. Color difference between model teeth and standard samples showed the most difference at the incisal area, but the gingival area showed the least difference. And the canine showed the least color difference from the comparison of standard sample, and the central incisor showed the highest difference (p < 0.01). Although the visually detectable difference of the measuring value showed notably depending on the type and measured area (p < 0.05), $L^*\;and\;a^*$ value showed notable differences depending more on the measured areas than on the type of the teeth.

• Restorative Dentistry and Endodontics
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• v.34 no.3
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• pp.199-207
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• 2009

The objective of this study was to evaluate the effect of color measuring instrument by measuring the color of dental composite resins. Nine shade light cured composite resin disks were prepared (diameter : 15 mm, thickness : 4 mm). CIE $L^*a^*b^*$ color scale of each disk was measured with 3 different types of spectrophotometer [MiniScan XE plus (Model 4000S, Hunter Lab, USA), CM-3500d (Minolta, Japan) and Specbos 2100 Miniature VIS Reflection spectrometer (Serial No: 319416, JETI Technishe VIS Instrumentic GmbH. Germany)]. Miniscan XE Plus and CM-3500d using identical measuring geometry with different size of viewing aperture. But Specbos 2100 using different measuring geometry. Within the limitation of this study, there were color difference (${\Delta}E^*$) from 2.4 to 7.8 between Miniscan XE Plus and CM-3500d, but $L^*$, $a^*$, $b^*$ values showed the high correlation. However, there were great color difference (${\Delta}E^*$) in the extent of about 20 between instruments with the different measuring geometry. Therefore, color scale measured by color measuring instrument should be used as a relative value rather than an absolute value in the field of dentistry.