• 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.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.13 no.2
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• pp.29-35
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• 2004

최근 심미적인 보철 치료에 대한 사람들의 관심이 높아짐에 따라 자연치와 더욱 조화롭게 보철 치료를 하는 것이 요구되고 있다. 이는 구조적인 심미성과 함께 자연스러운 색조 재현을 통하여 이루어지는데, 자연치의 색조는 매우 다양하고 부위별로 달라질 수 있기 때문에 단순히 shade guide상의 비교만으로는 정확한 색조를 얻기가 어렵다. 이러한 색조 선택의 부정확성 때문에 객관적으로 색조를 분석하는 많은 기계적 장치들이 고안되었고, 최근에 ShadeScan system(CYNOVAD, Canada), Vita Easyshade system(Vident, Canada) 등 디지털로 색조를 평가하는 시스템이 각광을 받고 있다. ShadeScan system은 한 번의 클릭으로 치아 이미지를 채득할 수 있고, 바로 컴퓨터를 통해서 이를 분석하여 원하는 shade map, translucency map 등을 얻을 수 있다. 또한 세 방향에서 조사되는 빛은 자체 calibration을 거쳤기 때문에 주변 광원이나 환경의 영향 없이 객관적으로 치아의 이미지를 채득할 수 있다고 한다. 사실 그 동안 이미지 채득이 객관적이라고 주장하는 많은 system이 있었지만 임상의들은 그 신뢰성에대해 의구심을 보였던 것이 사실이다. 이에 본고에서는 ShadeScan system이 반복 촬영 시 같은 색조재현을 할 수 있는지 실험하여 그 객관성에 대해 살펴보았다.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.4
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• pp.443-457
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• 2004

Purpose: The purpose of this study was to analyze and estimate whether each company may produce the color of artificial teeth as it stands, in the standard of vita classical shade guide using ShadeScan$^{TM}$ System. Material and methods: we chose the products of 6 companies -EFUCERA, IVOCLAR, ENDURA, TRUBYTE, DURADENT, and DURACROSS- estimated the shade value of each fixed point(cervical, body, and incisal area) of artificial tooth, and verified the equality among the samples from the same company. Results: First, the variation appeared significant at cervical and incisal area. It means that there were significant differences between cervical and incisal area although the most similar artificial teeth to the patients’natural teeth were provided. Second, the results in the body area showed that the variation between artificial and natural teeth was finite(p<0.05) in that area. Conclusion: it shows that the reproduction of colors of artificial teeth might be successful regarding the body is the most important part for a determination of the color of artificial teeth. However, more complements are necessary for the better reproduction of the color of artificial teeth between cervical and incisal area.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.5
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• pp.565-581
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• 2003

Statement of problem : A scientific examination and understanding of overall aspects of the natural dentition is the first step involved in making a satisfactory selection in the shade of an aesthetic prosthesis. Proper natural shade selection of the prosthetic restoration that is in harmony with the remaining dentition is as important aesthetically, as harmony of form and function in the anterior dentition. Clinically, the most commonly applied method of shade selection has been visual, but because of the subjective nature inherent to this method, shade selection results are variable and can be influenced by such factors as the technician, the type of shade guide used, and the type and intensity of the lighting. Purpose : The purpose of this study was to develop a more objective and scientific approach to examining and understanding the shade of teeth, which has in turn lead to the development of a number of shade analysis devices that present a more objective method of shade analysis. Material and Method : In this study, the shades of healthy anterior teeth were examined and analyzed using the recently developed digital shade analysis of the $ShadeScan^{TM}$ System. The study examined 80 individuals in their twenties, 40 males and 40 females, presenting 6 healthy, unrestored maxillary anterior teeth. Tooth brushing and oral prophylaxis were performed prior to evaluation. The ShadeScan handpiece was used to acquire images of the 6 maxillary anterior teeth. These images were analyzed using the Vita/Classical mode of the $ShadeScan^{TM}$ Software, and shade maps of each tooth were acquired and divided into cervical, middle, and incisal thirds. The shade distribution of each third, left and right symmetry, and gender differences were investigated and analyzed. Results : The results of the study are as follows : 1. An overwhelming majority of the examined teeth were found to possess shades belong to Group A, with the greatest variations occurring at the middle and cervical thirds of the maxillary central and lateral incisors, in both male and female subjects. 2. Canines of both male and female subjects showed left and right symmetry with uniform shade distribution of A4 and C4, while the lateral and central incisors showed left-right symmetry of the incisal 1/3 with a uniform shade distribution of A2 and A3 shades 3. No significant differences in shade distribution were seen between genders in maxillary canines, whereas maxillary central and lateral incisors showed differences at the middle and cervical thirds between male and female subjects The results of this study show that with the exception of maxillary canines, maxillary anterior teeth display a diverse shade distribution as well as gender differences. Conclusion : Clinically, when making a shade selection using the existing shade guide, one must consider the fact that even a single tooth consists of a variety of shades. The results of this study show that when selecting a shade from a number of groups is difficult, shades from A group are the most consistent with the natural shade or maxillary anterior teeth.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.3
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• pp.314-321
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• 2005

Objectives. The purpose of this study was to compare the shade changes in wet and dry conditions of natural teeth using two different intra-oral colorimeters. Materials and methods. Twenty volunteer subjects have no restorations and fillings in the maxillary central incisors were involved in this clinical study. The color of tooth was measured by two different instruments that were a Shade $Scan^{TM}$ System and a VITA $Easyshade^{(R)}$, Five times consecutive measurements were done for each subject with both instruments. Groups of measurement are an initial wet condition as control, dry in 5 minutes, 15 seconds after re-wetting with saliva, re-wetting after 5minutes and re-wetting after 30 minutes. Using ShadeScan $System^{TM}$, tooth image was captured and converted to the mapping image of Vitapan 3D master. Three main shades were chosen from each subject and calculated the area in Global Lab Image software. Data were analyzed using paired T-Test and Wilcoxon Signed Ranked Test. Using VITA $Easyshade^{(R)}$, color differences($\Delta$E) between measurements were analyzed with one sample T-test. Results. Using ShadeScan $System^{TM}$, there were significant differences between control group and dry(P=.023), dry and re-wetting 15 seconds, 5 minutes, 30 minutes as well(P=.021, P=.017, P=.030) in comparison of primary shade. However, comparing three main shades, there was no significant difference between control and dry(P=.105). Using VITA $Easyshade^{(R)}$, color differences($\Delta$E) between control and dry, dry and re-wetting 30 minutes were statistically different(P=.002, P=.022). Conclusion. Primary shade could be changed in dry and wetting procedure in time, however there was no significant shade changes in overall.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.3
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• pp.429-437
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• 2006

The purpose of this study was to evaluate the shade of primary incisors. One hundred and nineteen children 394 maxillary anterior primary incisors were assessed. Digital shade analysing system ($ShadeScan^{TM}$, Cynovad, Canada) was used for measuring the shades This system enabled to improve the accuracy and objectivity The images of the teeth were taken with $ShadeScan^{TM}$ and shade maps of the teeth were obtained with $ShadeScan^{TM}$ software. The shades of three regions (cervical third middle third, incisal third) of the teeth were evaluated. The results were as follows : 1. In cervical third of primary incisors, D2 and D3 were the major shades and D2 was the most frequent shade. 2. In middle third of primary incisors, C1, D2, and B1 were the major shades and C1 was the most frequent shade. 3. In incisal third of primary incisors, A2 was the most frequent shade and D2 shade followed.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.12 no.2
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• pp.39-47
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• 2003

• Journal of the Korean Society of Radiology
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• v.18 no.2
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• pp.179-185
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• 2024

By applying the various energy spectrum imaging functions of DECT, To quantitatively distinguish between contrast agent and calcification, changes in image quality are analyzed by comparing CNR and SNR. We investigated the level of dose reduction during two scans and one VNC scan. As a result, contrast agent and calcification were best distinguished in the 70 keV area, CNR and SNR were excellent, and scan dose was reduced by about 26.5%. Therefore, by applying DECT, meaningful results were obtained that could visually and quantitatively distinguish between the intravascular contrast agent and the shade of calcification. If clinical research is conducted in the future considering the patient's age, gender, and body type, quantitative analysis of calcification will be possible even with intravascular contrast agent flowing in, which will have a significant effect in reducing the patient's scan dose and the burden of multiple scans.

• 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.

• Current Photovoltaic Research
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• v.7 no.3
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• pp.65-70
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• 2019

As a demand of higher power photovoltaic modules, shingled, multi-busbar, half-cell, and bifacial techniques are developed. Multi-busbar module has advantage for large amount of light havesting. And, half-cell is high power module for reducing resistive losses and higher shade tolerance. Recently, researches on multi-busbar is focused on reliability according to adhesion and intermetallic compound between Sn-Pb solder and Ag electrode. And half-cell module is researched to comparing with full-sized cell module for structure difference. In this study, we investigated the factors affecting to efficiency and adhesion of multi-wires half-cell module according to wire thickness, solder thickness, and flux. The results of solar simulator and peel test was that peel strength and efficiency of soldered cell is not related. But samples with flux including high solid material showed high efficiency. The results of FE-SEM and EDX line scan on cross-section between wire and Ag electrode for different flux showed thickness of solder joint between wire and Ag electrode is increasing through solid material increasing. Flux including high solid material would affect to solder behavior on Ag electrode. Higher solid material occurred lower growth of IMC layer because solder permeate to sider of wire ribbon than Ag electrode. And it increased fill factor for high efficiency. In soldering process, amount of solid material in flux and solder thickness are the factor related with characteristic of soldered photovoltaic cell.