Department of Prosthetics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey.
J Prosthet Dent. 2012 Jul;108(1):9-14. doi: 10.1016/S0022-3913(12)60102-4.
There is limited information on the visual and instrumental evaluation of color match between a natural tooth and a ceramic crown.
The purpose of this study was to evaluate the influence of 2 shade guides on color match, and to evaluate the relationship between color difference (ΔE) values and examiners' assessments of the color match in ceramic crowns.
Thirty-three subjects were selected for a ceramic crown restoration of the maxillary central incisor. Two crowns were fabricated with selected shades from Vitapan Classical and Vita Toothguide 3D-Master shade guides for each subject. The color values of maxillary central incisors, selected shade tabs, and corresponding crowns were measured with a spectrophotometer. The ΔE values between the natural teeth and the crowns and between the selected shade tabs and the corresponding crowns were calculated for each subject and compared with the Student's t test (α=.05). In addition, 3 examiners visually evaluated the clinical acceptability of each crown on a scale from 1 to 6. The agreement among the examiners was assessed with the Kappa test. The scores of examiners for both shade guides were analyzed with the Wilcoxon signed rank test (α=.05).
The results revealed that the color difference values between the teeth and the crowns fabricated with the selected shades from the Vita Toothguide 3D-Master shade guide were significantly smaller than those of the Vitapan Classical guide (P=.003). Similarly, the color difference values between the selected shade tabs from the Vita Toothguide 3D-Master guide and the corresponding crowns were significantly smaller than those of the Vitapan Classical guide (P=.001). However, the ΔE values obtained for both shade guides were within the clinically acceptable range (ΔE<3.7). The kappa values implied moderate agreement among the 3 examiners. The median value of the examiners' scores was 2, which denoted an acceptable color match. In addition, the recorded scores of the 3 examiners showed that there was no significant difference in terms of the color match between the crowns fabricated with either of the 2 shade guides.
The ceramic crowns fabricated with the Vita Toothguide 3D-Master shade guide resulted in a closer color match to the natural teeth than those of the Vitapan Classical guide. However, the ΔE values and the examiners' scores were within the clinically acceptable range for both shade guides.
关于天然牙与陶瓷牙冠之间颜色匹配的视觉和仪器评估，信息有限。
本研究的目的是评估两种比色指南对颜色匹配的影响，并评估陶瓷牙冠的色差（ΔE）值与检查者对颜色匹配评估之间的关系。
选择 33 名上颌中切牙的患者进行陶瓷牙冠修复。为每位患者制作了两种牙冠，分别使用 Vitapan Classical 和 Vita Toothguide 3D-Master 比色指南中的选定色调。使用分光光度计测量上颌中切牙、选定的比色片和相应牙冠的颜色值。为每位受试者计算天然牙与牙冠之间以及选定的比色片与相应牙冠之间的ΔE 值，并与学生 t 检验进行比较（α=.05）。此外，3 名检查者使用 1 到 6 的等级对每个牙冠的临床可接受性进行视觉评估。使用 Kappa 检验评估检查者之间的一致性。使用 Wilcoxon 符号秩检验（α=.05）分析两种比色指南的检查者评分。
结果表明，使用 Vita Toothguide 3D-Master 比色指南中选定色调制作的牙冠与天然牙之间的色差值明显小于 Vitapan Classical 指南（P=.003）。同样，使用 Vita Toothguide 3D-Master 比色指南中的选定比色片与相应牙冠之间的色差值也明显小于 Vitapan Classical 指南（P=.001）。然而，两种比色指南获得的 ΔE 值均在临床可接受范围内（ΔE<3.7）。3 名检查者的 Kappa 值表明存在中度一致性。检查者评分的中位数为 2，这表示可接受的颜色匹配。此外，3 名检查者的记录评分表明，使用两种比色指南制作的牙冠在颜色匹配方面没有显著差异。
与 Vitapan Classical 指南相比，使用 Vita Toothguide 3D-Master 比色指南制作的陶瓷牙冠与天然牙的颜色匹配更为接近。然而，两种比色指南的 ΔE 值和检查者评分均在临床可接受范围内。
