紫外线照射老化对渗透树脂处理釉质白垩斑颜色稳定性的影响

目的评价紫外线照射老化对渗透树脂颜色稳定性的影响。方法选取前磨牙60颗,置于人工脱矿液中3d形成早期人工釉质龋,再随机分成3组,分别为对照组、渗透树脂处理组、涂氟处理组,将3组试件置于紫外线下照射老化,分别用色度计测量人工脱矿前、紫外线照射前、紫外线照射8、16、24 h的色度值CIE L*、a*、b*,分析色度值的变化。结果样本处理后,渗透树脂处理组与正常釉质的色差值ΔE*小于3.3,在紫外线照射老化后的8 h颜色发生了变化,16 h后颜色趋于稳定,颜色一直为肉眼无法分辨的色差范围内;对照组及涂氟处理组与正常釉质的色差值ΔE*均大于3.3,涂氟组相对于对照组来说,ΔE*减小,差异有统计学意义,在紫外线照射老化后,两组样本颜色无明显改变。结论渗透树脂能明显改善釉质白垩斑的美观,渗透治疗后的牙齿颜色短期稳定性满意。     

7种树脂基充填材料的颜色性能评价

目的探讨紫外线照射对光固化树脂基充填材料颜色及不透光度的影响。方法采用7种光固化树脂基充填材料（Aelite Flo、Filtek Z350 Flowable、Clearfil AP-X、Dyract AP、Z100、Durafill VS、Filtek Z350 Universal）各制作5个树脂试件。用色度计测量颜色参数L*、a*、b*（CIE 1976 L*a*b*系统）及Y刺激值（CIE 1931 XYZ系统）,然后将7种试件经紫外线照射老化8、16、24 h后再次测量颜色参数及Y刺激值,计算7种试件经紫外线照射后的色差及不透光度。结果紫外线照射后试件均发生了一定程度的颜色变化,色差变化范围从8 h的1.85~3.21到24 h时的2.88~4.55;不透光度出现了一定程度的升高,变化范围从照射前的0.75~0.82到照射24 h后的0.80~0.98。其中,Z100和Filtek Z350 Flowable试件的色差值较大,Filtek Z350 Universal试件的不透光度较大。结论紫外线老化能够引起树脂基充填材料发生颜色改变和不透光度升高,不同产品的颜色稳定性有所差异。     

2种树脂黏固剂产品与人牙本质黏结性能的研究

目的探讨2种树脂黏固剂对进行和不进行处理的人牙本质是否具有相同的黏结效果。方法将30枚人牙本质试件分为6组,分别施以不同表面的处理（A、B组不处理 C、D组磷酸酸蚀15s E、F组磷酸酸蚀15s后使用One-step通用型黏结剂）。A、C、E组使用RelyX Unicem双固化树脂黏固剂,B、D、F组使用Bis-cem双固化树脂黏固剂,制作牙本质/树脂黏固剂黏结试件,测试剪切黏结强度,扫描电镜观察黏结界面形态。结果统计分析可知组A和组B的黏结强度值分别低于组C、E和组D、F,组C与组E间以及组D与组F间无统计学差别。RelyX Unicem树脂黏固剂除对于磷酸酸蚀牙本质的黏结强度高于Biscem树脂黏固剂外,牙本质进行其他表面处理或不处理时,2种树脂黏固剂间的黏结强度无明显差别。结论磷酸酸蚀能够提高RelyX Unicem和Biscem2种自黏结树脂黏固剂对牙本质的黏结强度。     

不同品牌光固化树脂材料颜色稳定性评价

目的探讨紫外线对几种树脂基材料老化颜色的影响。方法制作树脂试件5枚/组(A组,Biscem;B组,PermaCem;C组,Choice;D组,Elite Flo;E组,Clearfil AP-X;F组,Dyract extra;G组,Durafill VS;H组,Filtek Z350Universal)。在黑暗环境保持24h后用色度计测量颜色值CIE L*、a*、b*,随后各组试件分别在紫外线照射老化8h、16h、24h再次测量,对结果进行统计分析。结果照射后试件均显示了一定程度的颜色值变化,树脂水门汀色差值变化范围从8h内的2.31~2.60到24h时的3.27~7.19,树脂充填材料色差值变化范围从8h内的1.35~2.66到24h时的3.36~14.31。其中,PermaCem、Durafill VS、FiltekZ350Universal24h后出现较大的色差值,其余组间无明显差异。结论紫外线老化能够引起树脂基材料发生颜色改变,除PermaCem、Durafill VS、Filtek Z350Universal同类产品不同品牌的颜色稳定性24h后无明显差异。     

人工老化对不同厚度瓷聚体及不同类型树脂黏固材料颜色稳定性的影响

目的 评价人工老化后不同厚度瓷聚体与不同类型树脂黏固材料联合体的颜色稳定性,为临床合理选择和应用瓷聚体贴面以及粘接剂提供参考。方法 3种厚度（1.00、0.75、0.50 mm）瓷聚体Ceramage分别与光固化树脂水门汀RelyX Veneer、双固化树脂水门汀RelyX Unicem和流动树脂Filtek Z350 Flow共3种类型树脂黏固材料制备瓷聚体-树脂黏固材料联合体样本,共9组（每组5个样本）。所有样本同时放入氙灯老化仪中进行人工加速老化,采用分光光度仪测量老化前后样本的明度（L*）、红绿色品（a*）和蓝黄色品（b*）值,计算老化前后明度变化（ΔL）、红绿色品变化（Δa）、蓝黄色品变化（Δb）和色差（ΔE）。用双因素方差分析探讨瓷聚体厚度和树脂黏固材料类型对老化前后ΔE的影响。结果 瓷聚体厚度及树脂黏固材料类型对联合体老化前后ΔE均有影响,且两者间存在交互作用（P<0.05）。所有组ΔE均小于3.3,老化后L*、 a*、b*值均降低,且ΔL均小于2.0。结论 瓷聚体厚度与树脂黏固材料类型对瓷聚体-树脂黏固材料联合体的颜色稳定性有影响;联合体老化后的明度变化和色差均在临床可接受的范围内。     

A、B色系IPS E.max LT底层材料色度值和相对透明率测定

目的:测定A、B色系IPS E.max LT底层材料的CIE-1976-L*a*b*色度值和相对透明率。方法:制作直径为13mm、厚度为0.3 mm和0.5 mm的A、B色系盘状IPS E.max LT试件,色号包括A1、A2、A3、A3.5、A4、B1、B2、B3、B4,共计18组(n=5),应用CM-5分光测色计测试试件在标准黑、白背景下的表面光反射率Y值,记录Yb、Yw平均值,计算相对透明率(Yb/Yw);测试A、B色系瓷锭的色度值。结果:同一色系内,各组瓷锭明度值的总体均数不相等,组间差异具有显著性(P<0.01)。从A1到A4、B1到B4,明度值均逐渐减低。相同厚度、相同色系的试件组间相对透明率差异无显著性(P>0.05),相对透明率数值分布范围为0.330 9～0.587 5。相同色号、不同厚度的2组试件组间差异均具有显著性,0.3 mm组底层材料的相对透明率小于0.5 mm组(P<0.05)。结论:厚度是A、B色系IPS E.max LT底层材料相对透明率的重要相关因素。     

4种氧化锆类全瓷修复体光学性能评价

目的：使用2种不同透明性氧化锆及饰瓷材料制作4种氧化锆类全瓷修复体，比较其光学性能。采用透明性（TP）及色差值（△E）为评价指标，为临床修复偏灰色基牙提供参考。方法：使用2种不同透明性A2色二氧化锆（贝特福美学全锆、Cercon低透氧化锆）及配套体瓷粉，制作4组氧化锆类全瓷试件，包括高透明性二氧化锆烧结牙本质瓷（A组）、低透明性二氧化锆烧结牙本质瓷（B组）、高透明性二氧化锆烧结不透明瓷及牙本质瓷（C组）和低透明性二氧化锆烧结不透明瓷及牙本质瓷（D组）。试件尺寸为14 mm×14 mm×1.5 mm，每组6个，共24个。用Shade Eye NCC色度计测色仪，分别测量试件在黑白背景上的颜色参数（计算TP值）、钛合金和A3色光固化复合树脂上的颜色参数（计算△E值）。采用SPSS 17.0软件包进行统计学分析。结果：4组试件的TP值不同，在2种背景下的△E值也不同，具有统计学差异（P<0.05）,TP值由小到大依次为D组相似文献   

纳米树脂颜色及透光率的老化因素分析

目的:利用紫外线加速三种纳米树脂材料老化,探讨老化后颜色及透光率的变化.方法:分别采用3M Z350A2、A3色;Shofu BeautifulⅡA2、A3色;Clearfil Majesty A2、A3色纳米树脂各制作3个盘状试件.利用分光光度仪测量初始CIEL*、a*、b*值及透光率t值,然后将各组树脂试件放置于紫外线下照射刺激老化8、16、24h后,测量每个照射时间后的颜色及透光率的数值.结果:各组树脂试件经紫外线老化刺激后均产生了颜色的变化.照射24h色差值达到最大值,3M组色差值最大,Clearfil组色差值最小、在色差值△E＜3以内的临床可以接受范围.各组透光率值变化较小.结论:紫外线老化刺激能够引起纳米树脂颜色改变,但透光率值变化不大.     

体层厚度对Ceramage聚合瓷树脂修复体颜色的影响

目的研究体层树脂厚度的变化对Ceramage聚合瓷树脂修复体颜色的影响。方法制作遮色层厚度为0.2mm、体层厚度分别为0.8、1.0、1.2、1.4、1.6mm的A2色Ceramage聚合瓷树脂试件,同时制作厚度10mm无遮色层的体层树脂试件作为对照组。使用Vita Easyshade电脑比色仪测定各组试件的L*、a*、b*值,并计算各厚度组与对照组之间色差值⊿E。结果随着体层厚度的增加,试件的L*值、a*值与b*值均逐渐降低,1.4mm和1.6mm厚度组与对照组之间的色差值⊿E小于1.5NBS。结论在临床适用范围内,体层树脂厚度变化对聚合瓷修复体的颜色有影响。当遮色层厚度为0.2mm时,体层树脂在1.4～1.6mm左右的厚度范围内,A2色Ceramage聚合瓷修复体能较理想再现选定的颜色。     

不同桩核材料对四种牙科底层瓷颜色的影响

目的 探讨3种桩核材料对4种牙科底层瓷颜色的影响,以期为修复医师正确选择适宜的修复材料提供参考.方法 制作A2色热压铸二硅酸锂玻璃陶瓷(Empress Ⅱ,A组)、Z2色瓷沉积氧化锆陶瓷(B组)、氧化锆陶瓷(Cercon base color,C组)、氧化锆陶瓷(Cereon base,D组)底层瓷试件各5个,A组试件厚度为0.80 mm,B～D组试件厚度为0.50 mm.采用色差计测量4组底层瓷试件在金铂合金、镍铬合金和复合树脂背景上的色度值,并计算每种底层瓷在不同背景间的色差值(△Eab*).结果 B、C和D组试件在不同背景间的色差均值分别为(0.14±0.08)、(0.90±0.20)和(0.99±0.09),不易为人眼所辨别(△Eab*<1.5),而A组试件在不同背景间的色差均值为(2.83±0.70),能够为人眼所辨别(△Eab*>1.5).结论 玻璃陶瓷易受背景颜色的影响,宜在与牙齿颜色相近的桩核条件下使用;氧化锆的遮色能力强,适用于基牙严重变色或染色以及各类非牙色桩核等情况.     

Changes in opalescence and fluorescence properties of resin composites after accelerated aging.

OBJECTIVES: Opalescence and fluorescence properties and the correlated translucency and masking effect of resin composites may change after aging. The objective of this study was to determine the changes in opalescence and fluorescence properties of resin composites after accelerated aging for 150 kJ/m2. Changes in translucency and masking effect were also determined. METHODS: Color and spectral distribution of seven resin composites (A2 shade, 1-mm thick) were measured in the reflectance and transmittance modes under ultraviolet light (UV)-included and excluded conditions. Opalescence parameter (OP) was calculated as the difference in yellow-blue (Deltab*) and red-green (Deltaa*) coordinates between the reflected and transmitted colors under UV-included and excluded conditions. For the fluorescence evaluation, color differences (FL-Ref and FL-Trans) by the inclusion or exclusion of the UV-component of the standard illuminant D65 in the reflectance and transmittance modes were calculated. Under UV-included and excluded conditions, the translucency parameter (TP) was calculated, and the masking effect (ME) was calculated as the color difference between a specimen over a black tile and black tile itself. Repeated-measures 2-way analysis of variance at the significance level of 0.05 was performed for the values before and after aging. RESULTS: OP values in UV-included and excluded conditions did not change significantly after aging. FL-Ref and FL-Trans, TP values and ME values in UV-included and excluded conditions changed significantly after aging (p<0.05). The ranges of changes after aging in DeltaE*ab units were: OP, -0.50 to 0.74; FL, -1.19 to 0.15; TP, -1.37 to 0.13; and ME, -0.49 to 0.33. SIGNIFICANCE: Opalescence of resin composites did not change but fluorescence was not detected after accelerated aging for 150 kJ/m2. Translucency and masking effect changed significantly after aging.     

Color stability of resin cements after accelerated aging

PURPOSE: To study the color stability of different resin cements after accelerated aging. METHODS: The color stability of a self-adhesive resin cement (Unicem), one resin-based composite cement (Variolink II), one compomer cement (Principle) and one hybrid ionomer cement (FujiCEM) was studied. Two curing modes of Unicem (self-cured and dual-cured) and Variolink II (light-cured and dual-cured) were also tested. Specimen disks (n = 5) were prepared with a polytetrafluoroethylene split mold and subjected to accelerated aging for 150, 300 and 450 kJ/m2. Color (CIELAB system) was measured before and after each of the three aging cycles on a reflection spectrophotometer. deltaE*, deltaL*, deltaC* and deltaH* were calculated and analyzed by ANOVA. RESULTS: The largest color change occurred during the first 150 kJ/m2 aging cycle, where deltaE* values ranged from 5.6 to 20.5 with Principle showing the least color change and FujiCEM the most. The color changes of all the tested materials were perceptible. The greatest changes were recorded for deltaL* and/or deltaC*. All specimens became significantly rougher and showed evidence of cracking and degradation after aging except Variolink II.     

四种全瓷修复材料的透光度比较

目的采用全瓷试样,对四种全瓷材料进行透光度测试,为全瓷修复的临床应用提供参考依据。方法选择四种全瓷材料：IPS Empress 2、VITA In-Ceram AIumina、VITA In-Ceram Zirconia及CerconZircinia。每种材料各做出厚为（0.5±0.05）mm,直径为14mm之试样8片（n=8）,使用色度计进行试样之透光度测试。结果透光度由高至低依序为Em2 0.5mm（0.78）、InA 0.5mm（0.94）、InZ 0.5mm（1.0）、Cer 0.5mm（1.0）。结论 IPS Empress 2为透光性最佳,适用于高度美观需求之前牙。VITA In-Ceram Alumina透光度偏低,而VITA In-Ceram Zirconia、Cercon均不透光,此二种烤瓷材料临床上宜应用于美观需求不高之后牙区。     

Curing-dependent changes in color and translucency parameter of composite bleach shades

Purpose: The goal of this study was to evaluate curing-dependent changes in color and translucency parameter (TP) values of composite bleach shades.
Materials and Methods: Thirty bleach shades of microhybrid and microfill composites were analyzed. Specimens (n = 5) were made as disks, 10 mm in diameter and 2 mm thick, using cylindrical molds. Specimens were polymerized for 60 seconds using a light-curing unit. Data were collected before and after composite curing using a spectrophotometer and analyzed using the appropriate color-difference metric equations.
Results: L*a*b* ranges (maximum minus minimum values) for microhybrids were 17.7, 2.91, and 7.97, respectively. Corresponding ranges for microfills were 14.4,1.26, and 4.27, respectively. Curing-dependent color differences varied from 3.7 to 12.0 δE* units, whereas TP values of cured resin composites varied from 2.0 to 7.1. Light-curing caused increase of microhybrid TP values (+0.7) and decrease of microfill TP values (-0.7). Color differences were found to be acceptable for five of six composite pairs of the same shade designation (each of them made by the same manufacturer) in post-curing measurements against white background.  

CLINICAL SIGNIFICANCE:

Curing-dependent color and TP changes indicate that dentists should use cured composite for matching of shade and translucency. Tested materials became less saturated, with microhybrids becoming darker and microfills becoming lighter after polymerization. Light-curing caused an increase in translucency of microhybrids and a reduced translucency in microfills.     

Change of color and translucency by light curing in resin composites

OBJECTIVE: This study evaluated color and translucency changes caused by light curing resin composite materials. METHODS: The CIELAB parameters (L*, a* and b*) of disks of A2 and opaque A2 shades of Charisma (Heraeus-Kulzer), Solare (GC) and Filtek Supreme (3M) were evaluated on the backings of black, white and the material itself both before and after light curing to evaluate color and translucency changes (by means of calculating deltaE* and the translucency parameter, respectively). RESULTS: Solare and Filtek Supreme showed significantly smaller color changes during light curing than Charisma; however, the value of deltaE* of all the products/shades was still in the clinically unacceptable range. Regarding translucency changes during light curing, the A2 and opaque A2 shades of Charisma showed a statistically significant increase, although no difference was observed in the other products. CONCLUSIONS: Solare and Filtek Supreme tended to show less changes in translucency and color during light curing compared to Charisma. Nevertheless, the changes in color during light curing were still in the range of unacceptable color change. Therefore, direct shade matching of these materials for a precise shade match should be performed by using the cured material.     

Comparison of translucency between indirect and direct resin composites

OBJECTIVES: To measure the translucency of indirect and direct resin composites after curing, and to determine the influence of material and shade group combination on these properties. METHODS: BelleGlass NG (BG, indirect resin composite) and Estelite Sigma (ES, direct resin composite), each composed in three shade groups (EN, OD and TL for BG; BS, AS and OP for ES) of 16 shades were investigated. Resin composite was packed into a mold (BEC) and was cured with a light-curing unit (CWL). Secondary curing was performed in a proprietary curing chamber (CIC) for BG material. Color was measured at the BEC, CWL and CIC conditions in the CIELAB scale using a spectrophotometer. Translucency parameter (TP) was calculated as the color difference between a specimen over a white and a black background. RESULTS: TP values before curing were in the range of 7.7 (BG-OD) to 16.9 (ES-AS), and those after curing were in the range of 10.0 (BG-OD) to 21.5 (BG-EN). TP values of both materials were influenced by curing (p<0.05). There were significant difference in the TP values by the material and shade group combination, and the following homogenous subsets were found based on Tukey multiple comparison test: BG-OD相似文献   

Influence of color parameters of resin composites on their translucency

OBJECTIVES: To determine the influence of color parameters and the difference in color parameters by the background on the translucency of resin composites. METHODS: Eight light-curing resin composites, a total of 41 shades, were investigated. The color of specimens was measured after polymerization on a reflection spectrophotometer with the SCE geometry over white and black backgrounds. The translucency parameter (TP), contrast ratio (CR) and the difference in color parameters by the background (DeltaL*, Deltaa*, Deltab* and DeltaC*ab: values over the white background minus value over the black background) were calculated. Correlations between TP values, CR values at every 50-nm interval and the color parameters as well as the differences in color parameters by the background were analyzed with regression analysis. RESULTS: Correlations between TP values, and the color parameters and the differences in color parameters were significant except chroma difference (p<0.01). The correlation between TP values and chroma was significant (r= -0.489 and -0.603, p<0.01). The correlation between TP values and DeltaL* was very high (r=0.868). Correlations between the color parameters, the differences in color parameters and CR values were varied by the wavelength. TP values were highly correlated with the CR value at the wavelength of 700 nm. SIGNIFICANCE: More chromatic shades of commercial resin composites were less translucent. Translucency increased as the wavelength increases.     

Optical properties of four esthetic restorative materials after accelerated aging

PURPOSE: To determine the differences in CIE L*, a*, and b* values, translucency parameter (TP), opalescence parameter (deltaO*ab), and color difference caused by the fluorescence (deltaE*ab-FL) of resin composite, glass-ionomer, resin-modified glass-ionomer, and compomer of A2 shade before and after accelerated aging. METHODS: Color and spectral distribution of the materials were measured according to the CIELAB color scale relative to the standard illuminant D65 in the transmittance and reflectance modes. Aging was performed in an accelerated aging chamber with an energy exposure of 150 kJ/m2. The translucency parameter (TP) was calculated as the color difference (deltaE*ab) of the specimen over white and black backgrounds. Opalescence parameter (deltaO*ab) was calculated as the difference in blue-yellow coordinate (deltab*) and red-green coordinate (deltaa*) between the transmitted and reflected colors of a 1 mm-thick specimen. Color difference by the fluorescence (deltaE*ab-FL) in reflectance mode was calculated as an index of fluorescence. Differences and changes in optical properties were analyzed by the repeated-measures ANOVA. RESULTS: Type of material and the mode of measurement (transmittance and reflectance) influenced CIE L*, a* and b* values significantly (P< 0.05) before aging. Accelerated aging influenced CIE L*, a* and b* values. Aging and the type of material influenced TP, deltaO*ab and deltaE*ab-FL values significantly (P< 0.05).