Teeth how to brush are yellow for the following reasons: 1, because the original color of the teeth is slightly yellowish, not white color, teeth mainly by enamel and dentin composition, located in the center of the teeth dentin is a light yellow, surrounded by dentin outside of the enamel is transparent and a little bit of glossy color, so these two substances wrapped together will present the human health of the teeth, really! The color is slightly yellowish, outside the sense of gloss, which is normal, healthy. 2, may be due to the teeth have pigmentation deposits on the surface of the teeth, pigmentation through the brushing of the teeth there is no way to get rid of it, so how to brush are yellow.