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。

Effect of five kinds of pigments on the chromaticity of dental zirconia ceramic

PURPOSE: All-ceramic dental restorations should match the colour of the natural teeth in order to fulfill aesthetic demands. The goal of this study was to evaluate the colouration of zirconia ceramic by adding five kinds of pigments. The influence of the pigments concentrations on the chromaticity were also analysed. METHODS: Different concentrations of five kinds of pigments were added on zirconia powder, then compacted at 200MPa using cold isostatic pressure, sintered to 1400 degrees centigrade and hold for two hours. The chromaticity of sintered bodies were measured with chroma meter. RESULTS: The colours achieved by the different pigments were presented in the CIELab system. The a* value increased with the added amount of Er(2)O(3), while b* value raised with the increasing amount of CeO(2) and Pr(6)O(11). However, three pigments failed to decrease L* value and the sintered body looked too bright. The sintered bodies were brown when adding Fe(2)O(3) to zirconia. Adding MnO2 could decrease the L* value of sintered bodies significantly, but had little influence on the a* and b* value. CONCLUSION: Five kinds of colorized zirconia ceramic could cover with the chromaticity range of dental ceramic which necessitate further investigation. Supported by Research Fund of Science and Technology Committee of Shanghai Municipality (Grant No.03JC14053) and Shanghai Leading Academic Discipline Project (Grant No.T0202).