Comparison of the translucency of shaded zirconia all-ceramic systems

Kurtulmus-Yilmaz, Sevcan,Ulusoy, Mutahhar The Korean Academy of Prosthodonitics 2014 The Journal of Advanced Prosthodontics Vol.6 No.5

PURPOSE. The purpose of this study was to evaluate and compare the translucency of shaded zirconia allceramic systems. MATERIALS AND METHODS. Translucency of 3 different zirconia all-ceramic systems colored by different techniques was compared with a lithium disilicate glass-ceramic (IPS e.max Press). Square-shaped specimens with 0.5 mm thickness were fabricated from In-Ceram YZ, ICE Zirkon and Katana systems in A1, A2 and A3.5 shades according to Vitapan Classical shade tab (n=11). Specimens were then veneered and glazed with corresponding veneer ceramic recommended by each zirconia system manufacturer and the total thickness was set to 1.5 mm. Translucency measurements were performed with VITA Easyshade Compact spectrophotometer after each stage and translucency parameter was calculated. Data were statistically analyzed with repeated measures ANOVA and Tukey multiple comparison test. RESULTS. The control group was significantly more translucent than the zirconia systems (P<.05). ICE Zirkon cores showed the least translucency; neither In-Ceram YZ nor Katana systems were superior to each other in terms of translucency. Translucency of all specimens was decreased after veneering, and the translucency rankings were changed. CONCLUSION. Coloring technique did not have a significant effect on translucency of zirconia cores. Although zirconia systems were less translucent than lithium disilicate glass ceramic, they had partial translucency and there were translucency differences among the zirconia systems. Chroma affected the translucency of precolored zirconia cores.

Comparison of the translucency of shaded zirconia all-ceramic systems

Mutahhar Ulusoy,Sevcan Kurtulmus-Yilmaz 대한치과보철학회 2014 The Journal of Advanced Prosthodontics Vol.6 No.5

PURPOSE The purpose of this study was to evaluate and compare the translucency of shaded zirconia all-ceramic systems. MATERIALS AND METHODS Translucency of 3 different zirconia all-ceramic systems colored by different techniques was compared with a lithium disilicate glass-ceramic (IPS e.max Press). Square-shaped specimens with 0.5 mm thickness were fabricated from In-Ceram YZ, ICE Zirkon and Katana systems in A1, A2 and A3.5 shades according to Vitapan Classical shade tab (n=11). Specimens were then veneered and glazed with corresponding veneer ceramic recommended by each zirconia system manufacturer and the total thickness was set to 1.5 mm. Translucency measurements were performed with VITA Easyshade Compact spectrophotometer after each stage and translucency parameter was calculated. Data were statistically analyzed with repeated measures ANOVA and Tukey multiple comparison test. RESULTS The control group was significantly more translucent than the zirconia systems (P<.05). ICE Zirkon cores showed the least translucency; neither In-Ceram YZ nor Katana systems were superior to each other in terms of translucency. Translucency of all specimens was decreased after veneering, and the translucency rankings were changed. CONCLUSION Coloring technique did not have a significant effect on translucency of zirconia cores. Although zirconia systems were less translucent than lithium disilicate glass ceramic, they had partial translucency and there were translucency differences among the zirconia systems. Chroma affected the translucency of precolored zirconia cores.

Effects of tooth Whitening and topical Fiuoride Applocation on Shade and Translucency Changes in tooth with Early Caries Lesion

Hyun Riew Kim, Jung-Sook Lee, Myung-Gu, Kim, Yong-Sung 대한임상예방치과학회 2010 International Journal of Clinical Preventive Denti Vol.6 No.1

Objective: The purpose of this study was to evaluate shade and translucency change by means of various topical fluoride application after tooth whitening on teeth with artificial caries lesions. Materials and method: 84 extracted anterior teeth were selected and induced to artificial caries by 0.1 M lactic acid-sodium hydroxide buffer solution, then tooth whitening treatment were performed for 2 weeks. Topical fluoride application was sequentially applied for 4 times. Improvement of shade and translucency were checked by Shadescan and evaluated according to types of whitening agents, topical fluoride agents and application methods. Results: By application of tooth whitening agent, translucency seemed to be increased in all groups (p<0.05), but after 2 weeks, there was no significant difference within group and also between group comparisons (p>0.05). Except of 22% carbamide peroxide gel application group, value difference ratio was decreased significantly and value difference between the lesion and normal tooth area seemed to be increased (p<0.05). At the beginning of fluoride application, translucency was improved significantly in 0.1% sodium fluoride strip group and fluoride varnish application groups (p<0.05) ; at 4 weeks, all groups showed the significantly increased translucency (p<0.05). There was no significant difference between groups comparisons (p>0.05). Control group and 2% sodium fluoride strip application group showed constant increasing of value difference ratio between the lesion and normal tooth area (p<0.05) ; 0.1% sodium fluoride strip group seemed to be steady state ; fluoride varnish group showed continuous recovery of value difference ratio (p<0.05). Conclusion: It seemed that demineralized area of tooth with early caries was remineralized without any treatment, in addtion fluoride application could make it possible to accelerate recovery of tooth shade and translucency. Clinically in case of patient showed incipient caries in their anterior teeth, just applying whitening agent had any alternative plan could make additional inconsistency and demineralization. It was suggested that fluoride application after whitening to such patients could make more desirable improvement of shade and advanced remineralization.

Recovering Translucent Objects Using a Single Time-of-Flight Depth Camera

Hyunjung Shim,Seungkyu Lee IEEE 2016 IEEE transactions on circuits and systems for vide Vol.26 No.5

<P>Translucency introduces great challenges to 3-D acquisition because of complicated light behaviors such as refraction and transmittance. In this paper, we describe the development of a unified 3-D data acquisition framework that reconstructs translucent objects using a single commercial time-of-flight (ToF) camera. In our capture scenario, we record a depth map and intensity image of the scene twice using a static ToF camera; first, we capture the depth map and intensity image of an arbitrary background, and then we position the translucent foreground object and record a second depth map and intensity image with both the foreground and the background. As a result of material characteristics, the translucent object yields systematic distortions in the depth map. We developed a new distance representation that interprets the depth distortion induced as a result of translucency. By analyzing ToF depth sensing principles, we constructed a distance model governed by the level of translucency, foreground depth, and background depth. Using an analysis-by-synthesis approach, we can recover the 3-D geometry of a translucent object from a pair of depth maps and their intensity images. Extensive evaluation and case studies demonstrate that our method is effective for modeling the nonlinear depth distortion due to translucency and for reconstruction of a 3-D translucent object.</P>

투광 효과를 이용한 도자작품 분석

한영숙 한국도자학회 2011 한국도자학연구 Vol.7 No.2

The translucency of ceramics is a unique characteristic of porcelain, and the porcelain starts from the opaque clay, goes through the process of firing in high temperature, and transforms into porcelain with translucency. Starting from the eggshell porcelain of China in the 11th Century, many ceramic works which fascinated with the properties of porcelain focused on the translucency, and various works which used translucent effects have been developed. At this point, there is a need to organize the unique design characteristics of porcelain by collecting, classifying and analyzing a wide range of translucent porcelain works as the focus which have been progressed until now. Based on this, the ultimate aim of this research is to find new ways of expressing light as well as to make the most of the unique characteristic of porcelain as a medium, by focusing on the material properties of porcelain and expanding the formativeness of light which only used to play the role of assistance. With the translucent porcelain works as the focus, the formativeness created by light and ceramics can be classified into the following 4 categories. They are the semi-transparency, shading effects, expressions of color, and effects of light pattern, to which many of the works belong, are subdivided into overlay effects, etching effects and watermark effects of pattern. 도자기가 가진 투광성은 자기(porcelain)만이 가진 특성으로, 불투명한 흙에서 출발한 도자기는 고온의 소성과정을 거치면서 투광성을 가진 자기로 변모한다. 11세기 중국의 박태자기로부터 시작된 자기의 물성에 매료된 많은 작품들은 자기가 지닌 투광성에 집중하였고 현대에 이르기까지 투광효과를 이용한 작업들이 다양하게 전개되어 왔다. 이 시점에서 그간 진행되어 온 투광성 중심의 도자작품을 사례중심으로 폭넓게 수집하여 분류하고 분석함으로써 도자만이 가질 수 있는 조형적 특성을 정리해 볼 필요가 있다. 이를 바탕으로 자기의 물성에 집중하여 보조적 역할에 머물렀던 빛의 조형성을 확장시켜 도자라는 매체가 가진 고유한 특성을 살리면서 동시에 빛과 함께 빚어내는 새로운 표현가능성을 찾아내는 것이 연구의 궁극적인 목적이다. 투광효과를 이용한 도자작품을 중심으로 빛과 도자기가 빚어내는 조형적 효과는 다음 4가지로 분류된다. 반투명효과, 농담효과, 색채표현, 빛의 패턴화이며, 그중 다수의 작품이 속하는 농담효과는 다시 중첩효과, 에칭효과, 패턴의 비침효과로 세분화하였다.

Effects of Tooth Whitening and Topical Fluoride Application on Shade and Translucency Changes in Tooth with Early Caries Lesion

류현,김정숙,이명구,김용성 대한예방치과학회 2010 International Journal of Clinical Preventive Denti Vol.6 No.1

Objective: The purpose of this study was to evaluate shade and translucency change by means of various topical fluoride application after tooth whitening on teeth with artificial caries lesions. Materials and method: 84 extracted anterior teeth were selected and induced to artificial caries by 0.1 M lactic acid-sodium hydroxide buffer solution, then tooth whitening treatment were performed for 2 weeks. Topical fluoride application was sequentially applied for 4 times. Improvement of shade and translucency were checked by Shadescan and evaluated according to types of whitening agents, topical fluoride agents and application methods. Results: By application of tooth whitening agent, translucency seemed to be increased in all groups (p<0.05), but after 2 weeks, there was no significant difference within group and also between group comparisons (p>0.05). Except of 22% carbamide peroxide gel application group, value difference ratio was decreased significantly and value difference between the lesion and normal tooth area seemed to be increased (p<0.05). At the beginning of fluoride application, translucency was improved significantly in 0.1% sodium fluoride strip group and fluoride varnish application groups (p<0.05) ; at 4 weeks, all groups showed the significantly increased translucency (p<0.05). There was no significant difference between groups comparisons (p>0.05). Control group and 2% sodium fluoride strip application group showed constant increasing of value difference ratio between the lesion and normal tooth area (p<0.05) ; 0.1% sodium fluoride strip group seemed to be steady state ; fluoride varnish group showed continuous recovery of value difference ratio (p<0.05). Conclusion: It seemed that demineralized area of tooth with early caries was remineralized without any treatment, in addtion fluoride application could make it possible to accelerate recovery of tooth shade and translucency. Clinically in case of patient showed incipient caries in their anterior teeth, just applying whitening agent had any alternative plan could make additional inconsistency and demineralization. It was suggested that fluoride application after whitening to such patients could make more desirable improvement of shade and advanced remineralization.

New multi-layered zirconias: Composition, microstructure and translucency

Kolakarnprasert, Nantawan,Kaizer, Marina R.,Kim, Do Kyung,Zhang, Yu Elsevier 2019 Dental materials Vol.35 No.5

<P><B>Abstract</B></P> <P><B>Objectives</B></P> <P>To fully realize the range of indication and clinical advantages of the new multi-layered zirconias, a comprehensive understanding of their chemical composition, microstructure, low temperature degradation (LTD) resistance, and translucency properties is paramount.</P> <P><B>Methods</B></P> <P>A zirconia system (Katana, Kuraray Noritake), including 3 distinct grades of multi-layered zirconias, was selected for study: Ultra Translucent Multi-layered zirconia (UTML), Super Translucent Multi-layered zirconia (STML), and Multi-layered zirconia (ML). For different materials and their individual layers, the chemical composition, zirconia phase fractions, and microstructure were determined by X-ray fluorescence (XRF), X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM). Also, their resistance to LTD and translucency properties were characterized.</P> <P><B>Results</B></P> <P>Our findings revealed no major differences amongst layers, but the 3 materials were very distinct―UTML: 5Y-PSZ (5 mol% yttria-partially-stabilized zirconia) with ˜75 wt% cubic content and a 4.05 (±0.85) μm average grain size, STML: 4Y-PSZ with ˜65 wt% cubic content and a 2.81 (±0.17) μm average grain size, and ML: 3Y-PSZ with <50 wt% cubic content and a 0.63 (±0.03) μm average grain size. After water aging at 120 °C for 12 h, greater monoclinic content was found in ML. UTML and STML did not show detectable monoclinic phase. The translucency was similar among layers, and also between UTML and STML, which were superior to ML.</P> <P><B>Significance</B></P> <P>For each multi-layered zirconia grades, the layers are only differed in pigment types and contents, which yield remarkably natural shade gradients. Also, despite the significant compositional difference between STML and UTML, both materials showed similar translucencies.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Composition differs amongst various grades of multi-layered zirconias, but similar among the layers within each material. </LI> <LI> UTML has the highest cubic content, followed by STML and ML. </LI> <LI> ML exhibits the lowest translucency, whereas UTML and STML show a similar level of translucency. </LI> <LI> Only pigment composition differs among the layers of each material, resulting in different shades but similar translucency. </LI> <LI> Only ML is susceptible to hydrothermal degradation. </LI> </UL> </P>

Evaluation of translucency of monolithic zirconia and framework zirconia materials

İlkin Tuncel,Işıl Turp,Aslıhan Üşümez 대한치과보철학회 2016 The Journal of Advanced Prosthodontics Vol.8 No.3

PURPOSE The opacity of zirconia is an esthetic disadvantage that hinders achieving natural and shade-matched restorations. The aim of this study was to evaluate the translucency of non-colored and colored framework zirconia and monolithic zirconia. MATERIALS AND METHODS The three groups tested were: non-colored framework zirconia, colored framework zirconia with the A3 shade according to Vita Classic Scale, and monolithic zirconia (n=5). The specimens were fabricated in the dimensions of 15×12×0.5 mm. A spectrophotometer was used to measure the contrast ratio, which is indicative of translucency. Three measurements were made to obtain the contrast ratios of the materials over a white background (L*w) and a black background (L*b). The data were analyzed using the one-way analysis of variance and Tukey HSD tests. One specimen from each group was chosen for scanning electron microscope analysis. The determined areas of the SEM images were divided by the number of grains in order to calculate the mean grain size. RESULTS Statistically significant differences were observed among all groups (P<.05). Non-colored zirconia had the highest translucency with a contrast ratio of 0.75, while monolithic zirconia had the lowest translucency with a contrast ratio of 0.8. The mean grain sizes of the non-colored, colored, and monolithic zirconia were 233, 256, and 361 nm, respectively. CONCLUSION The translucency of the zirconia was affected by the coloring procedure and the grain size. Although monolithic zirconia may not be the best esthetic material for the anterior region, it may serve as an alternative in the posterior region for the bilayered zirconia restorations

Prenatal chromosomal microarray analysis of fetus with increased nuchal translucency

So Hyun Shim,Dong Hyun Cha 대한의학유전학회 2018 대한의학유전학회지 Vol.15 No.2

Nuchal translucency is an important indicator of an aneuploid fetus in prenatal diagnostics. Previously, only the presence of aneuploid could be conἀrmed by conventional karyotyping of fetuses with thick nuchal translucency. With the development of genetic diagnostic techniques, however, it has been reported that subtle variations not detectable by conventional karyo-typing might occur in cases of pathologic clinical syndrome in euploid fetuses. One of the newer, high-resolution genetic methods in the prenatal setting is chromosomal microarray. The possible association between nuchal translucency thickness with normal karyotype and submicroscopic chromosomal abnormalities detectable by microarray has been studied. How and when to apply microarray in clinical practice, however, is still debated. This article reviews the current studies on the clini-cal application of microarray in cases of increased nuchal translucency with normal karyotype for prenatal diagnosis.

Prenatal chromosomal microarray analysis of fetus with increased nuchal translucency

Shim, So Hyun,Cha, Dong Hyun Korean Society of Medical Genetics and Genomics 2018 대한의학유전학회지 Vol.15 No.2

Nuchal translucency is an important indicator of an aneuploid fetus in prenatal diagnostics. Previously, only the presence of aneuploid could be confirmed by conventional karyotyping of fetuses with thick nuchal translucency. With the development of genetic diagnostic techniques, however, it has been reported that subtle variations not detectable by conventional karyo-typing might occur in cases of pathologic clinical syndrome in euploid fetuses. One of the newer, high-resolution genetic methods in the prenatal setting is chromosomal microarray. The possible association between nuchal translucency thickness with normal karyotype and submicroscopic chromosomal abnormalities detectable by microarray has been studied. How and when to apply microarray in clinical practice, however, is still debated. This article reviews the current studies on the clinical application of microarray in cases of increased nuchal translucency with normal karyotype for prenatal diagnosis.