Color matching in dentistry. I. The three-dimensional nature of color

It is possible to arrange color in a manner that makes this three-dimensional enigma understandable. The Munsell Color Order System is recommended as the system of choice for dentists who wish to gain a working knowledge of color. Once the dimensions of color (Hue, Value, and Chroma) become familiar terms, dentists will have the color language and the necessary tools to approach color matching problems in a logical manner.     

色彩学知识与牙科比色Ⅱ.影响视觉辨色的因素

临床比色板比色的本质是采用特殊的色板进行视觉辨色的过程,本次讲座将在色彩学基本知识的基础上分析影响视觉辨色的几个因素.     

Color matching denture bases for non-white patients

A technique has been described which offers an easy and practical approach to the matching of the basic color of the denture base to the basic color of the tissues. Further subtle characterizations and customizations are compatible to the technique.     

色彩学知识与牙科比色Ⅳ.牙科色彩识别相关的研究方法及进展

口腔色彩学研究是口腔医学科研领域的重要组成部分.口腔色彩学研究主要包括天然牙颜色研究、牙科色彩识别方法研究以及口腔材料光学特性研究.本讲将介绍与牙科色彩识别相关的科学研究方法及进展,以利于更多对口腔色彩研究感兴趣的医师深入到这个领域中.     

Color matching in dentistry. Part II. Practical applications of the organization of color

The three-dimensional nature of color and the importance of understanding this concept in approaching a color-matching problem were set forth in Part I.⁷ The practical application of the three-dimensional Munsell Color Order System to the design of an ideal dental shade guide and the correct way to use this guide were explained in Part II. Until such a guide and the porcelain to go with it become available, existing guides must be used. A means of extending their utility was reviewed. Recommendations were made for elevating color-matching procedures in dentistry to an acceptable level.     

Physical properties of root cementum: part 2. Effect of different storage methods.

This study examined the effect of 5 disinfection and storage protocols over different time periods on the hardness and elastic modulus of human premolar cementum. The sample consisted of 20 first premolars, which were divided into 5 groups of 4 teeth and stored in 1 of the following ways: (1) Miltons solution (1% sodium hypochlorite) for 10 minutes, (2) Miltons solution for 24 hours, (3) 70% alcohol, (4) desiccation, or (5) Milli Q (deionized water, Millipore, Bedford, Mass). Teeth in groups 1 and 2 were initially stored in Milli Q, tested within 6 hours, placed in their respective media, and retested. Groups 3, 4, and 5 were tested within 6 hours, then at 1 month, 2 months, and 3 months after extraction. Group 5 was further studied at 9 months, and 2 teeth in Group 4 were tested at 4 months. The hardness and elastic modulus of cementum was tested with the Ultra-Micro Indentation System (UMIS-2000, Commonwealth Scientific Industrial Research Organization, Australia) on unprepared specimens mounted on a 3-dimensional jig assembly. The results showed that storage in Miltons solution for 10 minutes had no significant effect on the hardness or elastic modulus, whereas storage for 24 hours caused a significant decrease in the hardness of cementum (P =.03). Storage in 70% alcohol for up to 4 months and in Milli Q for up to 9 months had no significant effects. Desiccation caused a significant increase in both the hardness and the elastic modulus from baseline to 3 months (P =.02 and P =.04, respectively), with most changes occurring within the first month. It was concluded that Miltons solution for 10 minutes could be considered an appropriate method for disinfection and removal of periodontal ligament fragments; however, its use for 24 hours should be avoided. Seventy percent alcohol and Milli Q are better storage methods, and desiccation should be avoided.     

Color matching ability of resin composites incorporating supra-nano spherical filler producing structural color

ObjectiveThe aim of this study was to evaluate the optical properties of supra-nano spherical fillers with different diameters and the color matching ability of resin composites (RC) incorporating these fillers.MethodsTwo types of SiO₂–ZrO₂ nano fillers with different diameters (150 nm and 260 nm) were used. The size distribution of each filler was measured and filler morphology was observed. The colors and spectral reflection spectra were measured by a spectral reflectometer. Experimental RCs incorporating ?150-nm/?260-nm filler (D150RC/D260RC) were prepared. For the base dentin part, disc specimens (Estelite Astelia: A1B, A2B, A3B, A3.5B, or A4B) were prepared with a cylindrical cavity. Estelite Astelia with NE shade was layered on top as the enamel layer. Disk specimens with different cavity depths were prepared using A3B shade. Experimental RC was used to fill the cavity, and spectral reflection spectrums were obtained and analyzed. Filtek Supreme Ultra (FSU) with A3B shade was used (n = 10) as a control.ResultsBoth ?150-nm and ?260-nm nano fillers showed uniform spherical shape and exhibited no aggregation. The maximum peaks of the spectral reflection spectra of the ?150-nm and ?260-nm nano fillers were 380 nm and 580 nm, producing structural colors close to blue and yellow, respectively. The spectral reflection spectrum of FSU had a broad peak at 540 nm, and D150RC had a significant peak at 420 nm. The D260RC specimen had a broad peak at 680 nm. The peaks of D150RC and D260RC significantly decreased in accordance with the shift in base RC shade from A1B to A4B. There was no significant difference in the peak of the reflection spectral spectra among different cavity depths of D260RC. These results suggest that the experimental RC could reflect base RC colors via the matrix resin, and the amount of transmitted light from the base RC was not much different with cavity depth.SignificanceD260RC producing structural color demonstrated a broad spectrum and reduction in brightness and chromatic value by adapting to surrounding restorative materials, suggesting its ability to enhance the chameleon (blending) effects to improve color matching. D260RC showed better color matching ability than resin composite containing uniformly sized ?150-nm SiO₂–ZrO₂ supra-nano spherical filler.     

色彩学知识与牙科比色Ⅰ.与牙科比色相关的色彩学基本知识

色彩学知识一直是口腔医学生、口腔临床医师培养中较欠缺的内容.很多医师比色时仅凭感觉,或者说凭眼睛的直觉,致使比色"没有把握"、"比不准".然而,色彩问题是美学修复过程中医师和患者高度关注的问题,单颗前牙修复时首要考虑的问题就是如何准确描述、再现颜色.天然牙的颜色千差万别,已有文献报道,需要用400多种颜色才能全面描述正常天然牙的各种颜色.牙科比色不应是一项盲目的工作,而应在色彩学知识的指导下科学地进行.