Teeth whitening: what works, and what quietly wrecks enamel
Reviewed by a registered dentist · Last reviewed 13 August 2026
Before spending anything on whitening, it is worth knowing which kind of discolouration you have. Some yellowing polishes off in twenty minutes. Some responds beautifully to bleaching. And some will not change at all no matter what you buy — in which case whitening is money wasted.
Two completely different problems
| Extrinsic (surface) staining | Intrinsic (internal) discolouration | |
|---|---|---|
| Where it is | On the enamel surface | Within the enamel and dentine |
| Causes | Tea, coffee, red wine, tobacco, paan, gutkha, some mouthwashes, iron supplements | Ageing, tetracycline taken in childhood, fluorosis, a dead nerve, trauma, genetics |
| Looks like | Brown or black patches, often near the gum line and between teeth | Uniform yellow-grey, banding, white or brown mottling, one dark tooth |
| Fixed by | Scaling and polishing — often that alone | Bleaching, and in resistant cases veneers or crowns |
A large proportion of people who book whitening actually need a scaling and polish. It costs a fraction as much and the difference is immediate. Getting that assessed first is the single most useful thing you can do.
Why teeth yellow with age — and why abrasives make it worse
Enamel is translucent; the dentine underneath is naturally yellow. As enamel thins with age and wear, more of that yellow dentine shows through. This is the key to understanding abrasive whitening products: charcoal powders, baking-soda-and-lemon pastes and hard scrubbing remove surface stain initially, then keep going and thin the enamel. The result after a year or two is teeth that look more yellow, and are permanently sensitive. It is one of the few genuinely irreversible mistakes in this area.
What actually works
| Method | Typical cost (India) | Result |
|---|---|---|
| Scaling & polishing | ₹800 – ₹3,000 | Removes surface stain. Often all that is needed. |
| Whitening toothpaste | ₹150 – ₹500 | Mild surface stain only. Will not change the underlying shade. |
| Custom take-home trays | ₹6,000 – ₹15,000 | The most reliable and controllable approach. 1–2 weeks of nightly wear. |
| In-clinic whitening | ₹8,000 – ₹25,000 | Fastest, one or two sessions. More post-treatment sensitivity. |
| Composite veneers | ₹3,000 – ₹8,000 per tooth | For discolouration that won't bleach. |
| Porcelain veneers | ₹8,000 – ₹25,000 per tooth | Most durable and natural, irreversible — enamel is removed. |
Indicative only, not a quotation. See our medical disclaimer.
Custom trays made from an impression of your own teeth are, for most people, the best value: the gel sits where it should rather than leaking onto the gums, and you keep the trays for cheap top-ups later.
Things to sort out before whitening
- Untreated decay or leaking fillings — peroxide reaching the pulp through a cavity causes severe pain.
- Gum disease — treat it first; whitening gel on inflamed gums is painful.
- Front-tooth crowns, veneers or composites — these will not change colour, and will stand out afterwards. Plan for replacing them to match.
- A single dark tooth — almost always a dead nerve, needing different treatment entirely.
- Existing sensitivity — use a desensitising toothpaste for two weeks first. See tooth sensitivity.
- Pregnancy or breastfeeding — whitening is generally deferred.
Making it last
Expect six months to two years. The determinant is what you drink. Rinse with water after tea, coffee or anything pigmented, use a straw for cold drinks, don't brush for an hour after acidic things, and keep tobacco and paan out entirely — those stain fastest and carry far more serious risks than discolouration. Occasional top-ups with your existing trays maintain the shade cheaply.
Where an online consultation fits
Very well, because the main question — extrinsic or intrinsic — is largely answerable by looking. A dentist can see your teeth on camera, tell you whether a scaling would achieve most of what you want, whether bleaching is likely to work on your particular discolouration, whether your existing fillings will become a problem, and give you a realistic expectation of the shade change. That saves people from spending ₹15,000 on a treatment that was never going to address their pattern of staining.
Will whitening actually work for you?
Find out before you spend — a dentist's opinion for ₹199.
Book a consultationFrequently asked questions
Does whitening damage enamel?
Supervised peroxide whitening at approved concentrations does not measurably damage enamel. Abrasive DIY whitening does, permanently. The difference is chemical versus mechanical.
Why did it make my teeth sensitive?
Peroxide passes temporarily through enamel into dentine and irritates the nerve. It is the commonest side effect and normally settles within a few days. Desensitising toothpaste before and during treatment, and spacing sessions further apart, reduces it substantially.
Are whitening strips safe?
Reputable strips at regulated concentrations are reasonably safe for mild surface staining, though they fit poorly over crowded teeth and leak onto the gums. Be careful with unregulated high-concentration products bought online, which can cause chemical burns.
Can I whiten with braces on?
No — the brackets mask the surface beneath and you would end up with patches. Whiten after the braces come off, once the enamel has settled for a few weeks.