The natural color of the teeth is not white as some people think. Multifactorial tooth color perception. The reflection and absorption of light by a tooth can be affected by a number of factors including specular light transmission through the tooth; specular reflection on the surface; reflection of light scattered on the surface; absorption and scattering of light within dental tissues; mineral enamel content; enamel thickness; The color of the ivory, the human observer, eye fatigue, the type of incident light, and the presence of external and intrinsic spots.[10] In addition, the perceived brightness of the tooth can change depending on the background brightness and color. [10]
The combination of the internal color and the presence of external spots on the surface of the tooth affects the color and thus the general appearance of the teeth.[11] Light scattering and absorption within enamel and dentin determine the intrinsic color of teeth and because enamel is relatively transparent, dental properties can play a major role in determining the overall tooth color.[10] On the other hand, the outer spots and color are the result of the colored areas formed within the acquired granules on the surface of the enamel and can be affected by lifestyle behaviors or habits.[11] For example, dietary intake of tannin-rich foods, poor brushing technique, tobacco products, and exposure to iron salts and chlorhexidine can darken the color of teeth.[11]
With age, teeth tend to be darker in shade.[12] This can be attributed to secondary dentin formation and thinning of the enamel due to tooth wear which contributes to a significant decrease in lightness and an increase in yellowness.[12] The shade of the teeth is not affected by gender or race.[12]
