If the congenital teeth are evenly yellow, or even part of the edges are yellow, you can choose to do cold light whitening.
If it is dental fluorosis or tetracycline, it has a wide range of yellow staining and many stripes. Only porcelain crowns or resin veneers cover the color. Among them, after nearly 20 years of clinical experience, resin can be said to be an immediate and minimally invasive choice for whitening anterior teeth, with a wide range of applications.