# Teeth Whitening: What Works, What Is Safe, and How Long It Lasts

By Dr. Sneha, BDS, MDS (Conservative Dentistry & Endodontics), The Dental Corner, Keshav Puram, New Delhi. Published 2026-11-07.

**Short answer:** Professional whitening done by a dentist is safe and can lighten teeth by several shades in a single visit. Results typically last one to two years with good care.

## Why teeth lose their colour

- Tea, coffee, cola and red wine
- Turmeric and strongly coloured foods
- Tobacco
- Age, as enamel thins and the yellower layer beneath shows through
- Plaque and tartar build-up

## Cleaning or whitening?

Scaling and polishing removes surface stains and tartar and brings back your natural shade. Whitening goes further and lightens the natural colour of the tooth itself. We normally clean first, and many people find that is enough.

## How professional whitening works

A whitening gel is applied to the teeth while the gums are protected. The gel breaks down stain molecules inside the enamel. The session takes about an hour and you see the change the same day.

## Is it safe?

Yes, when a dentist checks your teeth first and controls the strength of the gel. Temporary sensitivity for a day or two is the most common side effect.

Whitening is not advised during pregnancy, for children, or on teeth with untreated cavities or gum disease.

## Home remedies to avoid

- **Lemon, baking soda and charcoal powders** are acidic or abrasive. They wear away enamel, which makes teeth look more yellow over time.
- **Unbranded whitening kits bought online** may contain unsafe concentrations and can burn the gums.

## What whitening cannot do

Crowns, veneers and fillings do not change colour. If these are on your front teeth, tell us before whitening so we can plan a matching result.

## Keeping the result

- Avoid tea, coffee and coloured foods for 48 hours after treatment
- Rinse with water after tea or coffee
- Drink cola and similar drinks through a straw
- Brush twice daily and have your teeth cleaned every six months
- Stop tobacco

## Book a visit

If you have questions about this, we are happy to help. Consultation at The Dental Corner, Keshav Puram starts at ₹100. Call or WhatsApp +91 80765 81730.

*This article is general information and does not replace an examination by a dentist.*