School of Dentistry, University of Liverpool, United Kingdom.
J Dent. 2012 Jul;40 Suppl 1:e10-7. doi: 10.1016/j.jdent.2012.04.023. Epub 2012 May 2.
To assess the color difference values that represent the perceptibility and acceptability thresholds of denture teeth.
Eighteen interchangeable right upper central incisors denture teeth were selected to have color difference values from representative left upper central incisor denture tooth in a range of 0.4-11.4 ΔE* units measured with a spectrophotometer (CM 2600d, Minolta Konica, Japan). These teeth were placed in an artificial dental arch in a phantom head. Under controlled conditions, a total of 80 observers divided into 4 groups (technicians, nurses, dentists and researchers) were asked to report the perceptibility and acceptability of each of the color difference values. The findings was then analysed using logistic regression for determining the perceptible and acceptable thresholds of dental color differences.
The determined color difference values at which 50% of all observers could detect a color difference (50:50 probability) was 1.9 ΔE* units with a 95% confidence interval and ranged from 1.7 ΔE* units to 2.1 ΔE* units. The determined color difference value at which 50% of all observes preferred to replace the tooth because of unacceptable color difference (50:50 probability) was 4.2 with a 95% confidence interval that ranged from 3.9 ΔE* units to 4.7 ΔE* units.
Within the limitation of this study, the following conclusions were made: 1. The mean color perceptibility threshold was significantly lower than the mean color acceptability threshold. 2. Significant differences between different observers groups were noticed in determination of perceptibility and acceptability of color differences. The technicians groups displayed lower perceptibility and acceptability limits than the dental nurses and non-dental observers.
When shade matching artificial denture teeth to natural teeth, 50:50 perceptibility (1.9 ΔE* units) and acceptability (4.2 ΔE* units) thresholds are used to compare color difference values. The technicians group displayed lower perceptibility and acceptability limits than other observers.
评估表示义齿牙可察觉性和可接受性阈值的色差值。
从具有代表性的左上中切牙义齿牙中选择 18 个可互换的右上中切牙义齿牙，使用分光光度计（CM 2600d，Minolta Konica，日本）测量其色差值在 0.4-11.4ΔE*单位范围内。这些牙齿被放置在人工牙弓中假人头。在控制条件下，共有 80 名观察者分为 4 组（技术人员、护士、牙医和研究人员），要求他们报告每个色差值的可察觉性和可接受性。然后使用逻辑回归分析确定牙齿颜色差异的可察觉和可接受阈值。
确定所有观察者中有 50%能够检测到颜色差异的色差值（50:50 概率）为 1.9ΔE单位，95%置信区间为 1.7ΔE单位至 2.1ΔE单位。确定所有观察者中有 50%因颜色差异不可接受而希望更换牙齿的色差值（50:50 概率）为 4.2，95%置信区间为 3.9ΔE单位至 4.7ΔE*单位。
在本研究的限制范围内，得出以下结论：1. 平均颜色可察觉阈值明显低于平均颜色可接受阈值。2. 不同观察者组在确定颜色差异的可察觉性和可接受性方面存在显著差异。技术人员组的可察觉性和可接受性限制低于牙医护士和非牙医观察者。
当将义齿牙与天然牙进行色调匹配时，使用 50:50 可察觉性（1.9ΔE单位）和可接受性（4.2ΔE单位）阈值来比较色差值。技术人员组的可察觉性和可接受性限制低于其他观察者。
