types of tooth discoloration
Types of Discoloration. Tooth discoloration falls into two main types: extrinsic and intrinsic. Extrinsic discoloration occurs in the outer layer of the tooth, called the enamel; enamel stains can range from white streaks to yellow tints or brown spots and pits. Intrinsic discoloration occurs in the inner structure of the tooth, called the dentin, when the dentin darkens or displays a yellow (or gray) tint.