Evaluating the accuracy of tooth color measurement by combining the Munsell color system and dental colorimeter

Abstract

As we pay increasing attention to dental aesthetics, tooth color matching has become an important part of daily dental practice. This aim of this study was to develop a method to enhance the accuracy of a tooth color matching machine. The Munsell color tabs in the range of natural human teeth were measured using a tooth color measuring machine (ShadeEye NCC). The machine's accuracy was analyzed using an analysis of variance test and a Tukey post-hoc test. When matching the Munsell color tabs with the ShadeEye NCC colorimeter, settings of Chroma greater than 6 and Value less than 4 showed unacceptable clinical results. When the CIELAB mode was used, the a* value (which represents the red-green axis in the Commission Internationale de l'Eclairage color space) made no significant difference (p=0.84), the L* value (which represents the lightness) resulted in a negative correlation, and the b* value (which represents the yellow-blue axis) resulted in a positive correlation with ΔE. When the Munsell color tabs and the Vitapan were measured in the same mode and compared, the inaccuracies showed that the Vitapan was not a proper tool for evaluating the stability and accuracy of ShadeEye NCC. By knowing the limitations of the machine, we evaluated the data using the Munsell color tabs; shade beyond the acceptable range should be reevaluated using a visual shade matching method, or if measured by another machine, this shade range should be covered to obtain more accurate results.

Investigating the color changes on resin‐based CAD/CAM Blocks

“…a * is a measurement for redness or greenness of coloration while b * refers to yellowness or blueness. They are also referred to evaluate optical properties and should be recorded to determine the long‐term success of esthetic restorations …”

Comparación Espectrofotométrica de las Sesiones de Blanqueamiento Intracameral con Peróxido de Hidrógeno y Carbamida a Diferentes Concentraciones

“…En el método subjetivo la comparación visual no es 100 % confiable, no es reproducible ni predecible, es inconsistente en el tiempo y el color de las guías muchas veces no coincide con el diente natural (Gómez-Polo et al, 2017). Para eliminar la variabilidad que esto genera, surgieron sistemas de registro de color mediante dispositivos electrónicos que permiten mayor objetividad, no se ven influenciados por el ambiente, sus resultados son reproducibles, consistentes (Chang et al, 2012;Knezovic et al, 2016;Gómez-Polo et al), y de acuerdo con recientes estudios, la lectura de color provee resultados más exactos que el análisis por comparación estándar mediante guías de colores (Alsaleh et al, 2012;Alshiddi & Richards, 2015). De mucha utilidad son entonces los espectrofotómetros, considerados como la metodología gold standard en el campo de la ciencia y determinación del color dentario (Da Silva et al, 2008;Ioannidis et al, 2013;Weyhrauch et al, 2015).…”

“…Diversos estudios han utilizado este método para evaluar el color antes y después del tratamiento, utilizando el parámetro Delta E (DE) que se obtiene mediante una fórmula que va a tomar en cuenta las diferencias entre las medidas de las coordenadas L*, a*, y b*, va a evaluar la exactitud y aceptabilidad verdadera de la variación del color entre dos objetos, indicándonos la magnitud absoluta de la distancia cromática entre un color y otro (Chang et al;Chu et al, 2010;Ioannidis et al).…”

Laboratory Study of Color Stability of Different Types of Materials for Temporary Constructions

“…8 Determination of tooth color can be done by two basic methods: visual in a clinical environment and instrumental with the help of different devices -colorimeter, spectro-photometer and digital imaging. [9][10][11][12][13][14] Instrumental methods of color matching are increasingly used. 15 In the visual determination of color, a high variability of the selected color is observed with different determinations of the same colour.…”