利用数码相机测定面部皮肤颜色的初步研究

目的:利用数码相机进行面部皮肤颜色测定的可行性与合理性的研究.方法:在进行颜色采集之前,首先测定实验光源的稳定性.使用Canon EOS 20D单反数码相机,在实验光源稳定的时间内,以相同的拍摄参数(快门1/25 s,光圈4.5 自定义白平衡,ISO 800)采集122 例22～32 岁受试人群颌面部的皮肤颜色,拍摄文档保存为Jpeg格式.图像经Adobe photoshop7.0统一校色后,拾取皮肤CIE L*a*b*色度学空间颜色数据,利用SPSS 10.0做统计描述.结果:实验光源在21～70 min内是稳定的,可以达到比色要求.实验测得皮肤的L*a*b*色度学参数范围为:L* 49～66,a* 7～18,b* 5～22.结论:面部皮肤色度参数与测色手段和方式密切相关,数码相机作为面部赝复体的比色方法,在面部皮肤色彩信息全面采集、色彩信息准确传递方面,具有独特优势.     

数码摄影应用于牙科比色可行性的研究

目的:对数码相机应用于牙科测色进行实验探讨,与专业测色仪器比较分析其合理性与可行性.方法:使用数码相机在D65光源的d/0°观测方式下,拍摄3D-Master比色板,其测色结果与CRAIC QDI2000显微光谱分析仪、ShadeEye-NCC电脑比色仪的色度数据进行比较.结果:在比色板色片的明度、饱和度参数的排序上,3种仪器的测试结果表现基本一致;数码相机测定的比色片色度参数(L*a*b*/C*H°)与电脑比色仪的结果间没有统计学差异,和显微光谱分析仪的结果在明度参数L*上存在统计学差异,根据相关性检验的结果,3种仪器测得明度参数间存在非常显著的正相关(P＜0.0001).结论:在一定实验条件下,数码相机用于牙体色彩测试结果的稳定性与专业测色仪器基本一致,并在操作方面更有优势.     

三种牙科比色板与天然牙色度的比较分析

目的 通过测量天然牙的色度参数范围,并与三种常用比色板的色度参数范围进行比较,分析目前常用的牙科比色板存在的局限. 方法 使用数码照相机在D65光源的非球形漫射照明观测方式下拍摄比色板A(VITAPAN Classic)、B(VINTAGE Halo)、C(3D-MASTER)和上颌天然中切牙322颗,获得天然牙和3种比色板的色度参数范围并进行比较. 结果 天然牙色度参数95%正常值的范围分别如下:明度(L*)为61.631～73.250,红绿色品(±a*)为-0.719～1.879,黄蓝色品(±b*)为8.701～17.790.与天然牙相比,比色板A的色度参数范围较窄,缺少红色品与高明度色片,饱和度分布不均匀;比色板B的红色品范围较A有所扩大,但饱和度偏高;比色板C的色度参数范围最大,其饱和度和明度可完全覆盖天然牙相应的色度参数范围,但仍缺乏红色品色片. 结论 与本组天然牙的颜色范围相比,目前临床常用比色板存在覆盖不全和色片分布不均匀的局限,总体缺乏偏红色调色片.     

137例老年人上前牙色度分析

目的:研究老年人上前牙的颜色特点.方法:采用Shade Eye-[2]NCC第2代电脑比色仪,检测137例老年人612颗活髓上前牙的L*、a*、b*值,与100例年轻人200颗活髓上前牙比较,应用SAS 6.0软件包对数据进行t检验.结果:老年组上前牙色度值范围为中切牙L*:71.2±6.22,a *:-0.97±1.12,b *:15.9±5.04;侧切牙L*:69.6±5.52,a *:-0.6±1.18,b *:13.9±4.15;尖牙L *:68.4±5.99,a *:-0.15±1.02,b *:19.6±4.87.左右同名牙L *、a *、b *值差异无显著性(P>0.05);中切牙、侧切牙、尖牙之间两两比较,L *、a *、b *值均有显著差异(P<0.05).中切牙L *值最大,侧切牙次之,尖牙最小;中切牙a *值最小,侧切牙次之,尖牙最大;侧切牙*b值最小,中切牙次之.尖牙最大.各牙位间的色差(△E),中切牙与侧切牙为2.945NBS,尖牙与中切牙为4.629NBS,尖牙与侧切牙为5.832NBS.青年组中切牙的L *、a *、b *的平均值分别为75.82、-0.11和12.68,尖牙的L *、a *、b *的平均值分别为72.07、1.22和17.92.老年组上前牙显示较小的L *值和a *值、较大的b *值(P<0.05).结论:老年人上前牙颜色特点为,中切牙较侧切牙及尖牙明亮;侧切牙的色彩较中切牙及尖牙浅;尖牙较切牙偏红、偏黄.与青年组相比,老年人前牙显示的色度更暗,红色减少,黄色增加.     

仿牙色四方多晶氧化锆陶瓷的制备及色度学分析

目的:研制6种天然牙颜色匹配的牙科四方多晶氧化锗陶瓷.方法:以稀土氧化物(Pr6O11、CeO2、Er2O3)和过渡元素氧化物(MnO2)为着色剂,采用粉体掺杂方法,在四方多晶氧化锆陶瓷粉体中添加不同质量分数的着色剂,制备出6种有色四方氧化锆陶瓷,通过Shade-eye电脑比色仪比较6种牙色四方氧化锆陶瓷和Vita classical比色板之间的明度、色相、彩度差异,分析色度差的大小.为临床应用提供依据.结果:本实验获得的6种着色的四方氧化锆陶瓷的b*值在天然牙和Vita比色板覆盖范围内,接近天然牙的颜色;L*值范围从68.8～80.37;a*值范围从-1.0～0.9,b*值范围从12.2～17.93.结论:以Pr6O11、CeO2、Er2O3、MnO2氧化物作为着色剂,制备与天然牙颜色匹配的四方多晶氧化锆陶瓷是可行的.     

三种比色板的色度分析

目的：测定、分析三种比色板色度值。方法：采用国际照明委员会(CIE)1976L*a*b*色度系统，用Shade-Eye NCC测色仪和Shade Eye Viewer分析软件，对Vitapan3D-Master、Vita Lumin Vacuum和Ivoclar Chromascop三种比色板进行色度值测定、分析，并与中国人天然牙色度值比较。结果：三种比色板的L*值范围接近，但与中国人天然牙相比，L*值的上限都偏低，缺乏75-86之间的高明度值；Vita Lumin Vacuum比色板在相近L*值水平集聚了过多的色片，并且其a*,b*值范围都太窄；Ivoclar Chromascop比色板缺乏b*值小的色片。结论：Vitapan 3D-Master与中国人牙色度值匹配最好，缺点是缺少高明度色片；Ivoclar Chromascop缺乏饱和度较低的黄色调色片；Vita Lumin Vacuum的L*,a,*,b*值分布都不合理，远远不能满足中国人牙齿的比色要求。     

Vitapan 3D-Master 板与南京地区人群天然牙色度空间的比较

目的 研究Vitapan 3D-Master比色板与天然牙在色度空间上的适合性.方法 采CIE L*a*b*色度系统,用ShadeEye NCC测色仪对南京地区居民271人的2 159颗天然牙和Vitapan 3D-Master色板进行色度值测定,分析天然牙和比色板的色度空间分布,比较二者的适合性.结果 1)天然牙比Vitapan 3D-Master比色板色度空间分布区域广,切牙组与比色板的适合性较差,尖牙-前磨牙组适合性较好.2)在色度空间上,切牙色度a*值偏向绿色方向(-a*),比色板色度a*值偏向红色方向(+a*);切牙比色时缺乏L*值为71～78、a*值为-1.5～0.2色度空间范围内的比色片.3)按照可感知色差阈值△E*ab<1.4的标准,天然牙与Vitapan 3D-Master比色板相比,理论符合率为:切牙组33%,尖牙-前磨牙组150%.结论 Vitapan 3D-Master比色板不能满足南京地区居民牙齿临床比色要求.     

前牙冠修复体色差容忍度的初步研究

目的通过研究前牙陶瓷冠修复体的色差容忍度,为提高修复成功率提供有效配色方案。方法选取30名口腔修复科临床患者的单侧上颌中切牙缺损的冠修复体与对侧天然上颌中切牙为实验对象,使用数码相机在标准环境下分别采集单侧天然牙、修复体与天然牙的数码图像,在对图像进行色彩校正后,利用Photoshop识色软件进行色度分析。根据患者和医师对修复体颜色的满意度将修复体分成满意组和不满意组,对2组的色差数据进行Wilcoxon检验。结果颜色满意组修复体与天然牙的总色差△E为2.550 3,颜色不满意组修复体与天然牙的总色差△E为4.077 2,2组总色差的差异具有统计学意义（P＜0.01）。当修复体明度L*、b*、饱和度C*大于天然牙时,颜色满意组与颜色不满意组间△L*、△b*、△C*的差异无统计学意义（P>0.05）;当修复体明度L*、b*、饱和度C*小于天然牙时,颜色满意组与颜色不满意组间△L*、△b*、△C*的差异有统计学意义（P<0.01）。颜色满意组与颜色不满意组间色度差△a*和色相差△H°间的差异均有统计学意义（P<0.05,P<0.01）。结论控制口腔修复体与天然牙间的色差,是配色成功的关键因素;充分利用口腔修复体色差容忍度,将在一定程度上有利于提高修复体的成功率。     

Vitapan3D-Master比色板与南京地区人群天然牙色度空间的比较

目的研究Vitapan 3D-Master比色板与天然牙在色度空间上的适合性。方法采用CIE L*a*b*色度系统,用ShadeEye NCC测色仪对南京地区居民271人的2 159颗天然牙和Vitapan 3D-Master比色板进行色度值测定,分析天然牙和比色板的色度空间分布,比较二者的适合性。结果1）天然牙比Vitapan 3D-Master比色板色度空间分布区域广,切牙组与比色板的适合性较差,尖牙-前磨牙组适合性较好。2）在色度空间上,切牙色度a*值偏向绿色方向（-a*）,比色板色度a*值偏向红色方向（+a*）;切牙比色时缺乏L*值为71～78、a*值为-1.5～-0.2色度空间范围内的比色片。3）按照可感知色差阈值△E*ab<1.4的标准,天然牙与Vitapan 3D-Master比色板相比,理论符合率为：切牙组33％,尖牙-前磨牙组50％。结论Vitapan 3D-Master比色板不能满足南京地区居民牙齿临床比色要求。     

A2色的天然牙与成品树脂牙的同色异谱效应分析

目的对A2色的天然牙和不同品牌的A2色成品树脂牙在不同光源下的颜色参数进行测量,分析其颜色变化,比较其光谱反射曲线,并分析天然牙和成品树脂牙的同色异谱效应。方法采用PR-650型光谱扫描色度仪测量A2色的天然牙和3种品牌的A2色成品树脂牙在D65光源、A光源、CWF光源和紫外光下的颜色参数L*、a*、b*值和XYZ三刺激值,比较其光谱反射曲线,通过计算特殊同色异谱指数来分析天然牙和成品树脂牙的同色异谱效应。结果A2色的天然牙和成品树脂牙的L*、a*、b*值随着光源的改变而改变,二者的变化趋势不完全一致。天然牙和成品树脂牙之间、不同品牌的成品树脂牙之间的光谱反射曲线形状有较大区别,但是每条曲线都有3个以上的交叉点和重合处,在特定光源下可以达到颜色匹配,具有同色异谱效应。A2色的天然牙与成品树脂牙之间有较明显的同色异谱效应,天然牙与3种品牌成品树脂牙之间的特殊同色异谱指数在A光源下为3.48、2.52和3.36,在CWF光源下为1.21、1.90和2.79,在紫外光下为1.59、2.07和4.07。不同品牌的A2色成品树脂牙之间的特殊同色异谱指数在A光源下为1.08、0.10和1.01,在CWF光下为1.46、2.23和0.94,在紫外光下为2.55、2.69和4.64。结论光源对天然牙和成品树脂牙的颜色有较大影响,A2色的天然牙与成品树脂牙之间存在较明显的同色异谱效应。     

The use of objective digital matching to achieve an esthetic composite restoration

OBJECTIVE: To investigate the ability to match composite restorations to teeth using digital imaging and CIE L*a*b* color differences. METHODS: Ten extracted human central incisors were used. Eleven discs of composite of differing shades were produced and mounted on white cardboard to create a customized shade guide (CSG). The CSG was photographed next to each of the ten teeth in a phantom head using a digital SLR camera. The images were analyzed, and color differences (deltaE) between the teeth and the shade discs were calculated using CIE L*a*b* values. Three cavities were then drilled into the labial surface of each tooth. Composite shades with the lowest three deltaE values were then used to restore the cavities. Ten observers evaluated the teeth under a standard D65 light source and recorded the best match. RESULTS: The majority of the observers selected the lowest deltaE in six out of the 10 teeth, and in a further two out of 10 teeth the second lowest deltaE was chosen. CONCLUSION: The lowest deltaE selected by objective color matching was agreed as the best match by observers. The high correlation between digital and visual color matching confirms the ability of digital camera and image analysis software to detect color differences.     

Relation in color of three regions of vital human incisors.

OBJECTIVES: For an adequate color reproduction, it is very valuable to quantify the color distribution in human teeth accurately. The aim of this study was to determine the color relation between three tooth segments (cervical, middle and incisal) in vital upper central incisors, using digital photography. METHODS: Digital recordings of 64 upper right central incisors were made using a standardized head-camera setup. The L*a*b* values of three regions were attained from the standardized digital images using software. RESULTS: There were statistically significant linear correlations for L* and b* between the three tooth segments (all r's > or = 0.60; p < 0.001). The correlation coefficient for a* was lower compared to L* and b* values. The L* and b* values of cervical and incisal tooth segment could be calculated from L* and b* values of middle tooth segment. SIGNIFICANCE: These results show the potency for color mapping of a whole tooth surface by extrapolation of color values of only one part of the surface.     

ShoFu比色板颜色的计算机分析

目的：研究ShoFu比色板颜色分布情况。方法：选用CIE1976L*a*b颜色系统，按照JISZ8722标准，采用数码相机和计算机技术，在标准光镜下采集、测试、分析ShoFu比色板各区域的色度值。结果：ShoFu比色板各组内颈部、中部、切端部亮度的变化有一定规律性，R组及VR组色片的亮度高于A组。其余无明显规律。结论：ShoFu比色板色度值变化无明显规律。数码相机和计算机技术是牙冠色彩研究的一种新手段，值得进一步运用。     

Relations in color among maxillary incisors and canines.

OBJECTIVES: To establish the strength of color relation among the maxillary central incisor, lateral incisor and canine teeth by using digital photography. This relation might be useful for the color reconstruction of the missing part of a tooth from the color obtained from neighboring teeth. METHODS: The L*a*b* values of the maxillary incisors and canines were determined in 100 subjects. Paired t-tests, Pearson correlations and linear regression analyses were used to describe the relation of the L*a*b* values between the three teeth for each segment (cervical, middle and incisal). RESULTS: The mean L*a*b* values of the canines differed statistically significantly from the values of the central incisors (p<0.001) except for L* and a* values in the cervical segment between the lateral incisor and canine. The color differences between the incisors were statistically significant in fewer cases. The relation in color was the highest between the cervical segments of the three teeth, with respect to L* (r = 0.45-0.65; p < 0.001), b* (r = 0.49-0.55; p < 0.001), and a* (r = 0.38-0.61; p < 0.001), and no relation was found between the incisal segments of central incisor and canine. SIGNIFICANCE: There is a relation in color between the maxillary incisors and canines, which is stronger between the cervical than between the middle and incisal segments. Therefore, the color prediction is most reliable when the cervical parts of the teeth are used.     

IPS Empress 全瓷贴面颜色效果的初步研究

目的 评价IPS Empress全瓷贴面的遮色性能及其颜色的匹配性和稳定性。方法 18例患者采用IPS Empress全瓷材料制作贴面86个，分为四环素牙(A组)和非四环素牙(B组)2组进行观察，分别以所选比色板和相邻正常天然牙(C组)为对照。用ShadeEyeNCC电脑比色仪分别测量贴面修复前、后牙齿L^*a^*b^*值；以粘结后为基点，分别在0．5年、1年、2年后测量贴面的L^*a^*b^*值。用SPSS10．0软件分析修复前、后牙齿颜色的变化情况，贴面颜色与天然牙颜色的匹配性及修复后贴面颜色的稳定性。结果 贴面修复前、后，A、B2组牙齿颜色L^*a^*b^*值的差异均有显著性，色差值分别为5．01和4．15。A组贴面颜色与所选比色板的色差值为2．45；与基点相比，在修复2年后贴面的明度值有显著降低，但色差值的差异无显著性。B组贴面颜色与相邻天然牙的色差值为0．22，修复后贴面颜色无显著改变。结论 IPS Empress全瓷贴面对非四环素牙具有良好的遮色效果及颜色匹配性、稳定性；对四环素牙有一定的遮色能力，但其颜色与比色板不能完全匹配，修复后明度值有所降低，对其颜色效果尚需进一步观察。     

792个活体前牙色度学分析

目的：研究人活体前牙色度学分布。方法：采用数码照像计算机色度分析系统采集、分析132例受试者上前牙色度值及Vita比色板各色片的色度值。结果：正常人前牙色度值范围为L^＊ 62．64-81．24、a^＊ 4．67-11．74、b^＊ 14．45～24．09，上中切牙亮度值（L^＊值）最大，侧切牙次之，尖牙亮度值最小，上中切牙彩度值（a^＊和b^＊值）最小，侧切牙次之，尖牙彩度值最大，Vita比色板的色度值范围为L^＊ 62．09-73．41、a^＊ 0.67～2．74、b^＊ 8．09～18．08。结论：正常人前牙色度分布具有规律性，Vita比色板的色度值范围与正常人前牙色度值范围不匹配。     

中国西南地区1 944枚恒前牙冠颜色的测量

目的了解西南地区中国人正常前牙冠颜色的分布范围及性别、年龄对颜色的影响.方法以CIE1931XYZ、CIE1976L*a*b*颜色空间为基础,采用人体牙齿颜色测量系统对162名20～73岁出生地为云南、四川、贵州等西南省区人的1944枚前牙进行切、中、颈3个位点的测量分析.结果①西南地区中国人天然牙的各色度指标范围为L*42.383～67.428,a*-4.750～1.371,b*1.88～20.268,x0.298～0.393,y0.332～0.392,Y19.383～34.025.95%可信限的最大值与最小值之间的色差值为31.667CIEL*a*b*ΔE单位.②男、女性别之间虽有一定差异,但无统计学意义(P>0.05).③除b*值、x值在切1/3与年龄因素无明显相关外,其余指标在各个部位均与年龄因素呈明显相关(P<0.05).④L*、a*值与年龄呈负相关(r<0,P<0.01),随年龄增长牙冠明度下降,颜色趋于偏绿,且切、中、颈部位颜色变化一致.b*值与年龄呈正相关(r>0,P<0.01)随年龄增长,中、颈1/3颜色趋于偏黄,但切1/3变化不明显(P>0.05).结论西南地区中国人的正常牙颜色范围较广,前牙颜色无性别差异.牙齿颜色随年龄增加,明度下降,牙齿趋于偏黄、绿,但黄、蓝色相在不同的部位变化不一致.     

Comparison of the ability of different colour indices to assess changes in tooth whiteness

OBJECTIVES: The study investigates the suitability of different whiteness indices and colour parameters in assessing changes in tooth whiteness using a digital-colour imaging system. METHODS: Forty-six male and female subjects aged 18-70 years participated in the study and were divided into two groups. The control group was given a standard "non-whitening" dentifrice (Colgate Great Regular Flavour) and the test group received whitening strips (crest white strips). The latter contained 6% hydrogen peroxide and were worn for 30 min twice daily on the six maxillary anterior teeth. Digital images of teeth were captured using a Jai 3CCD digital camera with annular LED illumination array and the data obtained was used to calculate colour parameters (L*, a* and b*) and whiteness indices (WIC, WIO, W). Colour differences (delta L, delta a, delta b and delta E) and differences in whiteness indices were obtained and were compared between the test and control groups. Reliability and repeatability of the instrument were checked by comparing the digital data to the clinical data and also by comparing data obtained from different camera views for the same tooth. RESULTS: The test group showed significant changes in the colour parameters and whiteness indices over the 2-week period. It also showed significant correlation between the digital data obtained from lateral and central camera views for the same teeth. Digital data showed a similar trend to that of clinical data. The WIO index demonstrated the strongest discrimination between the test and control groups. CONCLUSION: The WIO index is appropriate for assessing changes in tooth whiteness. The digital imaging system is reproducible and reliable in evaluating changes in whiteness of teeth.