Before we talk about shade guides, concentrations, or how many shades lighter your teeth might go, there’s a more fundamental question:

Are your teeth and gums healthy enough to whiten?

This might sound like I’m gatekeeping, but I promise it’s the opposite. I want you to be able to whiten successfully and comfortably. And that requires making sure the foundation is right first.

Why Your Gum Health Matters

Whitening gel is a mild acid. In a healthy mouth, that’s fine, it does its job and the teeth handle it without issue. But in a mouth with active gum disease (bleeding, inflamed, or receding gums), whitening gel can cause significant irritation and discomfort.

If you notice your gums bleed when you brush, even just occasionally, please mention this before starting any whitening treatment. A healthy mouth before whitening means a comfortable, successful whitening experience.

What About Cavities?

Active decay in the mouth is a contraindication for whitening. Peroxide gel can penetrate a cavity and reach the inner layers of the tooth, causing pain and potentially making the decay worse.

This is why a proper dental check-up before whitening isn’t just a formality, it’s genuinely important. A dentist can spot issues that you might not be aware of and ensure you’re safe to go ahead.

Can Anyone Whiten Their Teeth?

Most adults in good dental health can whiten safely. However, whitening isn’t recommended for:

• Children and teenagers (under 18 — teeth are still developing)
• Pregnant or breastfeeding women (as a precautionary measure)
• People with very sensitive teeth or exposed dentine — can whiten, but with a very gentle approach
• People with certain restorations in prominent visible positions — needs discussion and planning

Whitening and Existing Restorations

If you have white fillings, composite bonding, crowns, or veneers on your visible front teeth, these will not change colour when you whiten. Your natural teeth will lighten; your restorations will stay the same shade.

The solution: plan ahead. If whitening is something you want, discuss it before any cosmetic restorations are placed. That way, we can whiten first and match the new restorations to your brightened smile.

The Right Order of Treatment

A question I often get: “Should I whiten before or after my bonding/veneers?” Always before.

Here’s why:

• Whiten your natural teeth to the shade you want to maintain
• Allow the shade to stabilise (about 2 weeks after completing whitening)
• Then place any composite bonding, veneers, or restorations in the colour that matches your newly brightened teeth

Doing it in reverse creates problems. You can’t whiten composite or porcelain after the fact.

A Word on Maintenance Whitening

Whitening isn’t permanent. Teeth will gradually pick up staining again over months and years. Most patients who’ve whitened professionally find that doing a “top-up” week of whitening every 6–12 months keeps their results fresh. Once you have your custom trays, top-up treatment is just the cost of replacement gel, very affordable.