The teeth usually have a seamless whitening transition zone from whiter near the biting surface of the tooth to less white near the gum line. This is normal and is an expected result because the tooth enamel is thinner near the gum line and will show through some of the tooth’s naturally yellower inner dentin layer. It is this slight transition that makes the tooth appear to be more natural and not just a monochrome “Chiclet” of a tooth, which looks very unnatural.