不同色号体瓷材料等量混色的研究

目的探索陶瓷材料颜色匹配中色调变化及明度变化的规律。方法制作镍铬合金片15片,于其上烧结不同色号的VINTAGE系列套装瓷粉,样本组的瓷样本依次由A1和A2、A2和A3、A3和A4、B1和B2、B2和B3、B3和B4色号的瓷粉按体积比等量混色后烧结而成;对照组瓷样本则依次由A1、A2、A3、A3.5、A4、B1、B2、B3、B4色号的瓷粉烧结而成。在PR 650分光光度仪上对瓷样本行色度学测试,利用Photo Research颜色分析软件进行色度学参数分析。结果相同色系不同色号瓷样本的L* a* b*值有统计学差异（P<0.05）,不同色号陶瓷材料等量混色后其色度学参数a*、b*值的变化是一种非线性关系,这种颜色的改变可为人眼辨别。结论VINTAGE系列套装瓷粉中A色系的明度变化梯度大于B色系;相同色系不同色号等量混色时,2号色和3号色的明度梯度最大;A色系红-绿变化明显,B色系黄蓝- 变化明显。     

不同比例同色系VITA MK95瓷粉混和后的色彩特征研究

目的：了解同色系VITA瓷粉按不同体积比例混合后相应色度学特征的变化规律，借以指导临床配色。方法：制作模拟临床金瓷修复体的烤瓷烧结体样本，对混合瓷粉的烧结体进行色度学分析。结果：A2和A3瓷粉按不同重量比混和后获得的瓷粉烧结体色度学指标，在A2和A3瓷粉的色度学指标范围之内，补充了比色板缺乏的天然牙色彩范围。随A2比例下降，明度值L^*下降，a^*值上升，而b^*值变化无统计学意义。初步量化分析其变化规律，得到相关拟合方程。结论：采用两种或多种瓷粉混和的方法，可以弥补受色号限制的金瓷修复体色彩不足的缺陷．所得数据可指导临床混色时参考。     

面积对陶瓷修复体体瓷色度学的影响

目的：探讨陶瓷修复体的色彩与其面积的关系。方法：分别制作厚度为2mm，直径为8mm、12mm、16mm、20mm的圆盘状B3色体瓷试件，在D65光源条件下，以分光光度计分别测试各组试件在黑色背景和在白色背景条件下的混合色。结果：随陶瓷试件直径由8mm增加至20mm，试件中心的色度值变化表现为：①彩度增加，色调趋向红色。②明度在黑色底板下增加，在白色底板下减小。②陶瓷试件直径由16mm增加至20mm时，试件色度值变化不明显。结论：陶瓷试件色度值随直径增大而趋向稳定。     

浅析金属烤瓷复体瓷崩裂原因及预防措施

金属烤瓷修复以其坚固、美观、舒适等诸多优点     

Vita AB色系体瓷粉混合的色度变化趋势

目的　考察按不同比例的VitaA2 ,B2 体瓷粉混合后色度变化趋势。方法　常规Ni-Cr合金片表面堆塑A2 遮色瓷及不同重量比例的A2 ,B2 混合体瓷粉 ,标准程序烧结 ,控制厚度 :遮色瓷 0 .3mm ,体瓷 1.0mm ,直径12 .0mm。白度色度计检测试件的色度参数 ,采用CIE1976L a b 表色系统 ,求取各组样本彩度值C ab及色相角H0 ab。结果　各组L 及b 值统计学上均无差异 ( P >0 .0 5 ) ;随A2 瓷粉重量比下降 ,B2 重量比增加 ,a 值逐渐下降 ,统计学上有显著差异 (P <0 .0 1)。结论　相同明度等级的VitaA2 、B2 瓷粉混合烧结后 ,其明度值 (L )基本保持不变 ;VitaA2 、B2 色系瓷粉混合后 ,其彩度 (C ab)向两瓷粉彩度区间移行 ,其色调 (H0 ab)可随相应瓷粉重量比增加而逐渐向其偏转     

VITA不透明瓷及体瓷瓷粉混合颜色的研究

目的 研究VITA不透明瓷及体瓷瓷粉颜色混合规律。方法 应用分光光度仪测试不同比例VITA VMK68 B1和B2色不透明瓷及体瓷瓷粉混合后的颜色，采用Munsell颜色标示系统对瓷粉混合后的颜色变化规律进行研究。结果 随着B1、B2色不透明瓷混合瓷粉中B2色瓷粉的增加，混合瓷粉的色相逐渐偏红，饱和度逐渐增加。随着B1、B2色体瓷混合瓷粉中B2色瓷粉的增加，混合瓷粉的色相逐渐偏黄，明度逐渐增加。不同混合比例的不透明瓷瓷粉问的色差为1．37～4．91，不同混合比例的体瓷瓷粉间的色差为0．56～2．35。结论 瓷粉混合可有效地扩大有限颜色瓷粉的颜色空间。有利于临床上制作颜色更为匹配的烤瓷修复体。     

多次烧结遮色瓷对金瓷修复体颜色的影响

探讨金属烤瓷修复体颜色匹配和色泽稳定性,提高金瓷修复体质量,一直是临床烤瓷修复面临的重要课题。本实验拟利用光谱扫描色度仪测试多次烧结遮色瓷层后金瓷修复体色相、明度、彩度的变化,探讨烧结变色规律及对金瓷修复体颜色的影响,为临床上金属烤瓷修复体的制作提供实验依据。     

YKH—Ⅰ非贵金属与西德VITA VMK 68瓷粉制作修复体的临床应用和体会

非贵金属烤瓷修复体具有强度高、耐磨性好、抗腐蚀性及组织相容好,且能仿照天然牙齿进行配色,色调优美逼真,因而是一种理想的齿料修复体。根据日本资料报道,美、日等国牙齿修复,冠、桥的50％以上均为金属烤瓷修复体。国内外也纷纷研制非贵金属以替代昂贵的贵金属。     

牙科陶瓷冠桥修复体材料的发展现状

牙科陶瓷具有良好的化学稳定性和极佳的生物相容性,在口腔修复领域备受青睐.陶瓷材料本身的低抗弯强度和脆性限制了其应用范围.本文阐述了烤瓷熔附金属修复体和瓷全冠修复体各自的特点、增强机制以及发展现状.     

The effect of repeated firings on the color of an all-ceramic system with two different veneering porcelain shades

STATEMENT OF PROBLEM: Color matching between a restoration and natural teeth is a common clinical problem. Despite careful shade selection, color of the restoration may be affected by fabrication procedures. PURPOSE: The purpose of this study was to determine the color changes of an all-ceramic restoration with 2 different veneering porcelain shades after repeated firings. MATERIAL AND METHODS: Twenty disc-shaped ceramic specimens, 4 mm in diameter with a 1-mm core thickness and 2 different veneering porcelain shades (A1, A3), were fabricated from a zirconia-based porcelain (DC-Zirkon) (n=10). Repeated firings (3, 5, 7, or 9 firings) were performed for the specimens, and color differences (DeltaE) were determined using a spectrophotometer. Repeated measures ANOVA was used to analyze the data (number of firings, veneering porcelain color). The Tukey HSD test and paired 2-tailed tests were performed for multiple comparisons (alpha=.05). RESULTS: The L*a*b* values of the ceramic system were affected by the number of firings (3, 5, 7, or 9) (P<.001) and the veneering porcelain shade (P<.001). Significant interactions were present between the number of firings and veneering porcelain shade for L* (P=.003) and b* (P=.042) values, but not for the a* value (P=.82). An increase in the number of firings of the specimens with both A1 and A3 veneering porcelain shades produced an increase in the L* value, resulting in lighter specimens (P<.001). For both A1 and A3 veneering porcelain shades, the a* value decreased after repeated firings, which resulted in more green specimens (P=.002). The b* value did not change after repeated firings (P=.09) for the A1 veneering porcelain shade; however, it increased for the A3 veneering porcelain shade, which resulted in more yellow specimens (P=.001). CONCLUSIONS: The color of the all-ceramic specimens with different veneering porcelain shades is influenced by repeated firings. However, color changes that occurred are clinically acceptable.     

The effect of repeated porcelain firings on corrosion resistance of different dental alloys

PURPOSE

The aim of this study was to evaluate the effects of repeated porcelain firing process on the corrosion rates of the dental alloys.

MATERIALS AND METHODS

Cr-Co, Cr-Ni and Pd-Ag alloys were used for this study. Each metal supported porcelain consisted of 30 specimens of 10 for 7, 9 and 11 firing each. Disc-shaped specimens 10 mm diameter and 3 mm thickness were formed by melting alloys with a propane-oxygen flame and casted with a centrifuge casting machine and then with the porcelain veneer fired onto the metal alloys. Corrosion tests were performed in quintuplicate for each alloy (after repeated porcelain firing) in Fusayama artificial saliva solution (pH = 5) in a low thermal-expansion borosilicate glass cell. Tamhane and Sheffe test was used to compare corrosion differences in the results after repeated firings and among 7, 9 and 11 firing for each alloy. The probability level for statistical significance was set at α=0.05.

RESULTS

The corrosion resistance was higher (30 mV), in case of 7 times firing (Commercial). On the other hand, it was lower in case of 11 times firing (5 mV) (P<.05).

CONCLUSION

Repeated firings decreased corrosion resistance of Pd-Ag, Cr-Co and Cr-Ni alloys. The Pd-Ag alloy exhibited little corrosion in in vitro tests. The Cr-Ni alloy exhibited higher corrosion resistance than Cr-Co alloys in in vitro tests.     

3种浓度过氧化脲漂白剂对牙科陶瓷表面粗糙度的影响

目的评估3种浓度过氧化脲漂白剂对牙科陶瓷表面粗糙度的影响。方法 80个瓷块按随机数字表法分成4组。A、B、C组所有瓷块进行为期3周,每天8 h的漂白,A组漂白剂为质量分数10%的过氧化脲,B组为质量分数15%的过氧化脲,C组为质量分数20%的过氧化脲;D组为空白对照组,浸泡于人工唾液里。表面粗糙度仪测量所有样本初始时和漂白1 d、2 d、3 d、1周、2周、3周后的瓷块表面粗糙度,并进行统计学分析。结果 A、B、C、D 4组瓷块的初始表面粗糙度分别为（0.073±0.003）μm、（0.073±0.002）μm、（0.072±0.003）μm、（0.074±0.003）μm,3周后的粗糙度分别为（0.073±0.004）μm、（0.073±0.005）μm、（0.074±0.006）μm、（0.074±0.005）μm。7个时间点,4组组间和组内表面粗糙度差异均无统计学意义（P＆gt;0.05）。结论 3种浓度过氧化脲漂白剂对牙科陶瓷表面无明显不良影响。     

Evaluation of some properties of an opaque porcelain fired simultaneously with the body porcelain

Recently, a porcelain-fused-to-metal opaque porcelain was introduced that does not require a separate firing before application of the body porcelain. The objective of this study was to determine the properties of this new opaque porcelain and its ability to bond to metal. The properties studied included flexural strength, linear firing shrinkage, coefficient of thermal expansion, powder particle size, and ability to bond to body porcelain and dental alloys. Sintering of this opaque porcelain was complete when fired at 1760 ° F (960 ° C) with a linear firing shrinkage of 13.1% ± 0.2%. No boundary between the opaque and body porcelains could be found with a scanning electron microscope after firing at 1760 ° F (960 ° C). The mean flexural strengths were 99 ± 7 and 101 ± 8 MPa respectively, for this opaque porcelain and a conventional opaque porcelain, and were not significantly different as assessed with Student's t-test (p = 0.548). The coefficient of thermal expansion for this opaque porcelain was 13.3 ± 0.2 × 10⁻⁶/ ° C. Particle size analysis showed a 63% increase in the particles below 5 μm for this opaque porcelain and bonding to two alloys was adequate as indicated by its cohesive failure. Simultaneous firing of this special opaque porcelain and body porcelain produced satisfactory sintering, strength, and bonding to metal.     

不同瓷表面处理方法对托槽与瓷面黏结性能影响的研究进展

瓷表面处理的目的是提高托槽与瓷修复体间的黏结强度，因此瓷表面处理方法是影响两者之间黏结强度的主要因素之一。本文介绍了不同的瓷表面处理方法在提高托槽与瓷面间黏结性能方面的最新研究进展。     

5种着色剂对牙科氧化锆陶瓷色度的影响

目的:研究5种着色剂对牙科氧化锆陶瓷色度影响的规律,为量化着色剂的添加比例提供依据。方法:在纳米氧化锆粉体中掺入不同比例的5种着色剂,200MPa冷等静压成型,于高温烧结炉中烧结到1400℃并保温2h,将烧结体研磨至(1.0±0.1)mm厚。观察烧结体的色泽并用色度仪测试其色度值。结果:氧化铒(Er_2O_3)能够使氧化锆陶瓷呈红色,对烧结体的b*值和L*值无影响。氧化铈(CeO_2)和氧化镨(Pr_6O_(11))均能使氧化锆陶瓷呈黄色,而对烧结体的a*值和L*值无明显影响。氧化铁(Fe_2O_3)能使氧化锆陶瓷呈黄褐色,随着剂量的增加,a*和b*值均增大,L*值略有下降。氧化锰(MnO_2)能够有效降低氧化锆陶瓷烧结体的明度,对a*和b*值无明显影响。结论:5种梯度着色氧化锆陶瓷能够覆盖牙科陶瓷所需的色度范围,值得进一步的研究与开发。