Whitening
What changes the color of a tooth, and what only claims to.
Tea Is Worse, and Water Is the Fix
Yes and yes, but the straw helps less than people think and one much simpler habit helps more. Also: tea stains worse than coffee does.
They Work Below the Enamel, Not On It
They work below the enamel rather than on it, which is why they are the one whitening method that does not thin the tooth. The real cost is elsewhere.
It Works, Then It Backfires
It genuinely works at first, which is why people swear by it. The mechanism that produces the early result is the same one that makes teeth darker later.
The Step Between the Before and the After
Yes, and that's the part the before-and-after photos skip. Enamel removed to fit a veneer does not come back, which makes the decision permanent from day one.
Why Your Teeth Are the Color They Are
Enamel is see-through. The yellow you're looking at is the layer underneath — and the thinner your enamel gets, the more of it shows through.