Faculty of Dentistry McGill University, Montreal, QC, Canada.
J Dent. 2011 Dec;39 Suppl 3:e3-10. doi: 10.1016/j.jdent.2011.11.008. Epub 2011 Nov 15.
Tooth shade is influenced by a combination of extrinsic-stains that are adsorbed to the enamel surface and by its intrinsic-shade resulting from the interaction of light with tooth structures. This study was designed to investigate how the variations in enamel ultrastructure may affect tooth optical properties.
One-hundred extracted teeth were collected from adult patients attending McGill-Undergraduate Dental Clinics. Shade-spectrophotometry, FTIR and XRD were used to assess tooth shade, enamel chemical composition and crystallography. The data obtained was analysed for Pearson correlation analysis and multiple linear regression analysis. The statistical significance was set at P < 0.05.
Tooth shade parameters varied dramatically within the studied population. Pearson correlation analysis demonstrated that tooth hue was associated with enamel hydroxyapatite (HA) crystal size (R = -0.358; B = -0.866; P = 0.007), tooth chroma was associated with enamel HA carbonization (R = -0.419; B = -99.06; P = 0.005), and tooth lightness was associated with both enamel HA crystal size (R = -0.313; B = -1.052; P = 0.019) and the degree of HA carbonization (R = -0.265; B=-57.95; P = 0.033). Multiple linear regression analysis demonstrated that the size of enamel HA crystals and the relative content of mineral carbonate were the most important predictors for tooth shade lightness (P = 0.018) and chroma (P=0.008), respectively. In contrast, enamel organic content had no correlation with tooth shade.
In the present study we have revealed that the tooth shade is regulated by the size of their HA enamel crystals. On the other hand, variation in the degree of enamel HA carbonization can also affect the tooth shade. These findings are of great relevance in dentistry since it provides better understanding of tooth aesthetics.
牙齿颜色受外源性染色物质吸附于釉质表面以及牙齿结构与光相互作用产生的固有颜色影响。本研究旨在探讨牙釉质超微结构的变化如何影响牙齿的光学性质。
从麦吉尔大学本科生牙科诊所就诊的成年患者中收集了 100 颗离体牙。采用分光光度法、傅里叶变换红外光谱（FTIR）和 X 射线衍射（XRD）评估牙齿颜色、牙釉质化学成分和结晶度。对获得的数据进行 Pearson 相关分析和多元线性回归分析。统计显著性水平设为 P<0.05。
在所研究的人群中，牙齿颜色参数变化很大。Pearson 相关分析表明，牙色与釉质羟磷灰石（HA）晶体大小有关（R=-0.358；B=-0.866；P=0.007），牙色与釉质 HA 碳化有关（R=-0.419；B=-99.06；P=0.005），牙色与釉质 HA 晶体大小（R=-0.313；B=-1.052；P=0.019）和 HA 碳化程度（R=-0.265；B=-57.95；P=0.033）有关。多元线性回归分析表明，牙釉质 HA 晶体大小和矿物质碳酸盐的相对含量是牙齿颜色明度（P=0.018）和彩度（P=0.008）的最重要预测因子。相比之下，牙釉质有机含量与牙齿颜色无关。
本研究揭示了牙齿颜色受 HA 牙釉质晶体大小的调节。另一方面，牙釉质 HA 碳化程度的变化也会影响牙齿颜色。这些发现对牙科具有重要意义，因为它可以更好地理解牙齿的美观。
