Two different colours
A tooth's appearance is the sum of two things: the intrinsic colour of the dentine showing through the enamel, and the extrinsic film of stain sitting on the outside.
Almost everything sold as whitening works on one of these and is silently useless against the other. Knowing which one you have determines whether a product will do anything at all.
| Intrinsic | Extrinsic | |
|---|---|---|
| Where it is | Inside the tooth structure | On the enamel surface |
| Common causes | Genetics, age, some medications, trauma | Coffee, tea, red wine, tobacco, some sauces |
| What shifts it | Peroxide-based agents that penetrate enamel | Abrasives, polishing, professional cleaning |
| Typical timescale | Weeks, with repeat application | Days, and it comes back |
| Reverts? | Slowly | Quickly, with the same habits |
How shade scales work
Clinical shade guides arrange tabs into hue groups — reddish-brown, reddish-yellow, grey, reddish-grey — then order them by value from lightest to darkest. Everyday shorthand collapses that into a single light-to-dark ladder.
ToothPal's Brightness dimension reads against a reference scale from your anterior photo and expresses the result out of 100. A step on a shade ladder is a meaningful move; half a step is within the noise of your lighting.
What actually works
- Professional cleaning. Removes extrinsic film comprehensively. Usually the single biggest visible change available, and most people underrate it because it isn't sold as whitening.
- Peroxide-based treatments (strips, trays, in-office). The only category that reliably touches intrinsic colour. Works, and comes with a real sensitivity trade-off for some people.
- Whitening toothpastes. Mostly abrasive or surface-active. Genuinely help with extrinsic film, largely don't touch intrinsic colour, and marketing rarely distinguishes.
- Habit change. Reducing the staining inputs — or rinsing with water straight after them — prevents the film that everything else is fighting. Least glamorous, most durable.
- Purple-toned products. Colour-correcting optics; the change is real to the eye and is not a change in the tooth. It also disappears with the product.
Why brightness is slow on your timeline
Shade drifts in fractions. Over six weeks of a good routine, a realistic move is a few points — not a shade jump. ToothPal will show that as a gentle upward line, which is a much more honest picture than a before-and-after photo pair taken under two different lights.
This is also why brightness is a poor first target. If you want early evidence that a routine is working, start with gum appearance or tongue cleanliness, which respond in days, and let brightness accumulate in the background.
Reading your own brightness line
- Same light, same time of day, every scan. Brightness is by far the most lighting-sensitive dimension.
- Expect a step after a professional clean, then a slow decay. That sawtooth is normal and informative — the slope of the decay tells you about your habits.
- A flat line after a whitening course is not a failure. It usually means you've reached your intrinsic colour, which is the floor.
- If it drops sharply and stays down, look at what changed in your drinks before you look at products.
Questions
No. ToothPal reads what your shade is doing over time. What you do about it is between you and a dental professional — and a professional opinion is genuinely worth having before a peroxide course, particularly if you have sensitivity.
Because the Makeover is an inspiration visualization, not a prediction. It shows a version of your smile, it doesn't forecast a result, and the app says so on the screen.
Your intrinsic colour is the floor and it's genetic. Most of the visible range available to you is extrinsic film — which is good news, because that part is cheap to address and repeatable.