Oral Health

Extrinsic stains sit on the surface of your enamel and a whitening toothpaste and a professional clean will lift them. Intrinsic colour is built into the tooth — from ageing, tetracycline, fluorosis or a dead nerve — and no toothpaste will touch it. Here is how to tell which one you have before you spend a cent.

Whitening toothpaste works on one thing only: extrinsic stain sitting on the surface of your enamel. It does NOT bleach your teeth or change their intrinsic colour - and the three mechanisms it uses (abrasion, chemical stain dissolution and blue covarine optics) are not equally safe.

Teeth are not naturally white. Enamel is semi-translucent and the dentine beneath it is naturally yellow, so the colour you see is dentine showing through enamel — which means a lot of “yellowing” is not surface stain at all, and scrubbing harder only makes it worse. Here is every cause of yellow teeth, extrinsic and intrinsic, and what actually works for each one.