Don’t whiten your child’s teeth just yet.
Their new permanent teeth aren’t really yellow, they just appear that way. We all think that the enamel on the outside of teeth is white, but really enamel is semi-translucent. So tooth color is mostly determined by the color of the material inside the tooth. As it so happens, the dentin inside teeth is quite yellow.
Baby teeth have almost no dentin compared to adult teeth. Also, the enamel on baby teeth is a little denser and is made of slightly different material so the overall effect is whiter. Permanent teeth will look particularly yellow inside a child’s mouth when they still have a few baby teeth close by. By the time they have a mouth full of adult teeth, they will all look whiter next to each other and a little more like normal teeth.