Professional whitening uses a controlled peroxide gel to lighten stains held within the enamel, typically by several shades in one 60-minute in-clinic session. It does not work on crowns, veneers or tooth-coloured fillings, which keep their original shade. Abrasive home remedies such as charcoal, baking soda and lemon juice do not whiten enamel — they wear it away, exposing the yellower dentine underneath and making teeth look darker over time.
Two completely different kinds of stain
Extrinsic stains sit on the outside of the enamel — tea, coffee, tobacco, paan. These come off with professional cleaning, not whitening. Many patients who book whitening actually need a scaling and polish, and are delighted with the result at a fraction of the cost.
Intrinsic stains are within the tooth structure: age-related yellowing as enamel thins and dentine shows through, tetracycline staining, fluorosis, or a single dark tooth after trauma. These are what whitening gel is actually for.
What the home remedies really do
| Method | What it actually does |
|---|---|
| Charcoal powder | Abrasive. Scrubs off surface stain while wearing enamel. No whitening effect. |
| Baking soda + lemon | Acid plus abrasive — a combination that actively erodes enamel. |
| Oil pulling | No credible evidence of whitening. Harmless if it does not replace brushing. |
| Whitening toothpaste | Mildly abrasive, removes some surface stain. Cannot change the underlying shade. |
| Unregulated online kits | Variable peroxide concentration, ill-fitting trays, gum burns. |
Swipe the table sideways to see every column.
The pattern is consistent: abrasion removes surface stain and creates a short-lived impression of whiteness, while thinning the enamel. Since the dentine beneath enamel is naturally yellow, thinner enamel means darker teeth. The remedy causes the problem it claims to solve.
What professional whitening involves
- Examination firstWhitening an untreated cavity or an inflamed gum is painful and pointless. Decay and gum disease are treated first.
- CleaningGel cannot act through plaque and tartar. Scaling comes before whitening, always.
- Shade recordingThe starting shade is recorded against a standard guide so the change is measurable rather than a matter of impression.
- The whitening sessionGums are isolated with a protective barrier and the gel applied in timed cycles over roughly an hour.
- AftercareA 'white diet' for 48 hours while the enamel pores are open — avoid tea, coffee, turmeric, red sauces and tobacco.
Sensitivity, and who should not whiten
Temporary sensitivity for one to two days is normal and settles by itself. A desensitising toothpaste in the fortnight before treatment reduces it considerably.
- Pregnant and breastfeeding women — deferred as a precaution.
- Children with developing teeth.
- Untreated decay, gum disease or cracked teeth — treat those first.
- Severe tetracycline staining, which responds poorly and is usually better served by veneers.
- Anyone expecting crowns or veneers to lighten. They will not.
Questions we get asked
How long do whitening results last?
Typically one to two years. Tea, coffee, red wine, tobacco and paan shorten this considerably; six-monthly professional cleaning extends it.
Does whitening damage enamel?
Professionally supervised whitening at controlled concentrations does not damage enamel. The damage associated with whitening comes from abrasive home remedies and unregulated kits with uncontrolled peroxide levels.
Why did my one dark tooth not match after whitening?
A single dark tooth is usually discoloured from within after trauma or root canal treatment. It needs internal bleaching or a veneer, not external whitening, which is why it lags behind the others.