Teeth Whitening: Everything You Need to Know Before You Start
White and radiant, but also safe and responsible.
A bright white smile is a beauty ideal for many people. No surprise, then, that whitening treatments have become incredibly popular. Ads often promise stunning results in a short time, but what exactly happens during such a treatment? And more importantly: is it safe?
On this page, I explain everything about teeth whitening: what really works, what to avoid, which methods exist, and why it’s so important to always whiten under the supervision of your dentist.
What determines the color of your teeth?
Teeth are made up of dentin and enamel. Enamel is nearly transparent but gives teeth a white sheen. The true color of your teeth is mostly determined by the dentin underneath, which is usually yellowish. The thicker the dentin, the more yellow your teeth may appear. Canines, for example, contain more dentin and are naturally darker.
As you age, tooth color changes. Enamel gradually wears away, exposing more dentin, which can make your teeth appear duller or grayer. Certain diseases or medications during tooth formation can also cause permanent discoloration.
Why do teeth become discolored?
There are many causes:
Food and drinks like coffee, tea, red wine, sodas, and fruit juices contain pigments that stick to enamel.
Smoking causes persistent stains that turn teeth yellow or brown.
Aging wears down enamel and thickens dentin, making teeth darker.
Tiny cracks in enamel over time allow colorants to penetrate.
Tartar and surface stains can make your teeth look darker but are removable with a professional cleaning.
Some toothpastes or mouthwashes (with tin or chlorhexidine) can cause staining.
Dead teeth (from trauma or root canal) discolor from the inside.
Is whitening suitable for everyone?
Not always. Your teeth must be healthy before starting. That’s why I recommend a dental check-up first. Your dentist will make sure there are no cavities and that restorations like fillings, crowns, or bridges are properly sealed.
Your dentist will also help decide if whitening is the best solution. Sometimes stains are superficial and removable with cleaning. If whitening is appropriate, you should know that fillings, crowns, and bridges don’t whiten—making them stand out more post-treatment.
Whitening methods: what are your options?
1. At-home whitening under dentist supervision
A safe and effective option for healthy teeth. There are 2 options:
– With custom-made bleaching trays: First, a digital scan of your teeth is taken, and a transparent, custom-fit whitening tray is made in a dental lab. You use it at home with a whitening gel with 16% PF
– With ready-to-use bleaching trays with 6% PF.
You’ll receive clear instructions. Typically, you wear the tray at night or for a few hours a day. You’ll start seeing results in a few days. Temporary sensitivity may occur—consult your dentist for adjustments or a break if needed.
2. Internal whitening for non-vital teeth
If a tooth has darkened internally—due to trauma or a root canal—internal bleaching may be the solution. The dentist opens the back of the tooth and places whitening gel inside. After a few days, it’s removed or replaced, and the tooth is sealed with a filling. This method is only for non-vital teeth.
3. Quick whitening treatments at dental clinics or “whitening shops”
Some clinics offer accelerated treatments using light or heat to activate the gel. While tempting, results are usually temporary. In Europe, peroxide concentration is legally limited to 6%, so one session rarely achieves the lasting effect of at-home treatment.
Warning: whitening shops without medical supervision pose a risk of gum or enamel damage. Always choose professional care.
Frequently Asked Questions
Is whitening harmful for teeth?
When done under professional guidance, it’s safe. Enamel becomes temporarily more porous, but it naturally remineralizes with saliva.
How long does a whitening treatment take?
With at-home methods, you’ll see results in a few days, and full effect usually within 2 to 3 weeks.
What can I eat or drink during whitening?
Avoid coffee, tea, wine, juices, and dark-colored foods. Smoking also reduces the effect. Avoiding these helps maintain the result.
What about fillings, crowns, or bridges?
They won’t whiten, and may appear more noticeable afterward. Your dentist can advise whether replacement is necessary to match the new shade.
Can I buy whitening products myself?
Retail and online products contain low (0.1%) peroxide levels. They’re legal but mostly ineffective. Plus, there’s no personalized guidance. DIY whitening without dentist supervision is discouraged.
Do whitening toothpastes work?
They don’t actually whiten teeth but help remove surface stains with enzymes or mild abrasives. Clean teeth appear brighter, though results are limited.
Conclusion: Get proper advice
A white smile starts with healthy teeth. Thinking about whitening? Talk to your dentist first. They’ll assess your teeth and recommend the safest, most effective method.
