Pande Neelam, Kolarkar Maithili S
Department of Prosthodontics, VSPM's Dental College and Hospital, Digdoh Hills, Hingna, Maharashtra, India.
MDS, Prosthodontics, Private Practitioner, Khamla, Nagpur, Maharashtra, India.
J Indian Prosthodont Soc. 2016 Jan-Mar;16(1):63-9. doi: 10.4103/0972-4052.175711.
To evaluate the shade reproduction of a pressable all-ceramic system placed on unstained and stained extracted maxillary central incisor using a color measurement spectrophotometer. In addition, to compare shade reproduction of this material with low translucency and medium opacity on unstained tooth and medium and high opacity on stained tooth.
Total 45 discs, with difference in the opacity of core, were used. After spectrophotometric evaluation, shade reproduction of the discs was compared and calculated by formula: Δ E* = (Δ L*+ Δ a*+ Δ b*)(1/2).
Student's t-test showed that in a sample of 15, the values of Δ E* for Group I - LT (Us.T.) lie between 0 and l, for Group II - MO (for Us. as well as S.T.) between l and 2, for Group III - HO (S.T.) are all above 5. Comparison among groups after t-test showed that mean Δ E* values of Group I - LT is less than Group II - MO for the unstained tooth, Δ E* for Group II - MO is less than average Δ E* value of Group III - HO for stained tooth.
All-ceramic with low translucency can be used for the fabrication of restoration on the unstained tooth as it gives the best shade reproduction. The medium opacity material may be used on the unstained as well as on stained tooth. However, the clinical implication of high opacity is limited when applied over the stained tooth as it is giving a shade reproduction, which is not within acceptable limits.
使用色彩测量分光光度计评估可压铸全瓷系统在上颌中切牙未染色和染色的离体牙上的颜色再现情况。此外,比较这种低透明度和中等不透明度材料在未染色牙齿上以及中等和高不透明度材料在染色牙齿上的颜色再现情况。
总共使用了45个在核的不透明度上存在差异的圆盘。经过分光光度评估后,通过公式:ΔE* = (ΔL* + Δa* + Δb*)(1/2)对圆盘的颜色再现进行比较和计算。
学生t检验表明,在15个样本中,第一组-LT(未染色牙齿)的ΔE值在0到1之间,第二组-MO(未染色和染色牙齿)在1到2之间,第三组-HO(染色牙齿)均高于5。t检验后组间比较表明,对于未染色牙齿,第一组-LT的平均ΔE值小于第二组-MO;对于染色牙齿,第二组-MO的ΔE值小于第三组-HO的平均ΔE值。
低透明度的全瓷材料可用于未染色牙齿的修复制作,因为它能提供最佳的颜色再现。中等不透明度材料可用于未染色和染色牙齿。然而,高不透明度材料应用于染色牙齿时,其临床意义有限,因为其颜色再现不在可接受范围内。