Hein Sascha, Morovič Ján, Morovič Peter, Saleh Omnia, Lüchtenborg Jörg, Westland Stephen
School of Design, University of Leeds, Leeds, UK.
HP Large Format Printing, HP Inc., Colchester, UK.
Dent Mater. 2025 Jan;41(1):51-57. doi: 10.1016/j.dental.2024.10.016. Epub 2024 Oct 29.
This study aimed to estimate the number of distinct tooth colors using a large dataset of in-vivo CIELAB measurements. It further assessed the coverage error (CE) and coverage error percentage (CEP) of commonly used shade guides and determined the number of shades needed for an ideal guide, using the Euclidean distance (ΔEab) and thresholds for clinical perceptibility (PT) and acceptability (AT) as evaluation criteria.
A total of 8153 untreated maxillary and mandibular anterior teeth were measured in vivo using calibrated dental photography. Cardinality was applied to determine the number of unique natural tooth colors. The CE and CEP were calculated for the Vita Classical and Vita 3D-Master shade guides, while the cardinality method was also used to estimate the number of shades required to adequately cover the estimated gamut of natural tooth colors.
The cardinality analysis revealed 1173 unique natural tooth colors. The CE for the Vita Classical shade guide was 4.1 ΔEab, with a CEP of 75 % beyond AT, while the 3D-Master shade guide had a CE of 3.3 ΔEab and a CEP of 70 % beyond AT. Based on cardinality computation, 92 discrete shades are required to adequately cover the estimated gamut of natural tooth colors with a CE of 1.2 ΔEab and CEP of 0.3 % beyond AT.
Cardinality computations estimated 1173 unique tooth colors while 92 discrete shades are estimated for full coverage. Such a number is impractical for physical shade guides, but new digital tools and 3D printing may offer future solutions. Both, the Vita Classical and 3D-Master shade guides do not fully represent the range of natural tooth colors.
This study highlights the limitations of existing shade guides and underscores the potential for new developments.
本研究旨在利用大量活体CIELAB测量数据集估计不同牙齿颜色的数量。进一步评估常用比色板的覆盖误差（CE）和覆盖误差百分比（CEP），并以欧几里得距离（ΔEab）以及临床可察觉性阈值（PT）和可接受性阈值（AT）作为评估标准，确定理想比色板所需的色阶数量。
使用校准后的牙科摄影技术对8153颗未经治疗的上颌和下颌前牙进行活体测量。应用基数计算法确定独特天然牙齿颜色的数量。计算Vita经典比色板和Vita 3D-Master比色板的CE和CEP，同时使用基数法估计充分覆盖天然牙齿颜色估计色域所需的色阶数量。
基数分析显示有1173种独特的天然牙齿颜色。Vita经典比色板的CE为4.1 ΔEab，超出AT的CEP为75%，而3D-Master比色板的CE为3.3 ΔEab，超出AT的CEP为70%。基于基数计算，需要92个离散色阶才能以1.2 ΔEab的CE和超出AT的0.3%的CEP充分覆盖天然牙齿颜色的估计色域。
基数计算估计有1173种独特的牙齿颜色，而完全覆盖则估计需要92个离散色阶。这样的数量对于实体比色板来说不切实际，但新的数字工具和3D打印可能提供未来的解决方案。Vita经典比色板和3D-Master比色板均未完全代表天然牙齿颜色的范围。
本研究突出了现有比色板的局限性，并强调了新进展的潜力。
