How long does whitening last, and why do teeth darken again?
Whitening does not stop teeth picking up colour again, and how long the result lasts varies:
- NHS: whitening is not permanent, but if you follow your dentist’s advice the effect may last for around three years.
- Oral Health Foundation: results can last several years, but this varies; smoking and drinks such as tea, coffee and red wine can cause staining to return more quickly.
- Bristol Dental School: over time the shade may darken again, and whitening will then need repeating.
Long-term data are limited: in a small 2002 study by Ritter and colleagues, 43% of 30 people recalled 9 to 12 years after tray whitening felt their colour had stayed stable for about ten years. Your starting colour matters too: according to MouthHealthy, the American Dental Association’s (ADA) patient site, yellow teeth will probably bleach well, brown teeth may respond less well and grey teeth may not bleach at all.
What can you eat and drink in the first days after whitening?
For the first days, you are usually advised to limit tea, coffee, cola, red wine, strongly coloured sauces and smoking; your dentist will tell you for how long. Research suggests a strict “white diet” may matter less than is often thought:
- In an analysis of five studies with 185 people, published in 2015, Matis and colleagues found that keeping to a white diet during whitening did not improve the result, and that red wine or dark fruit did not limit it.
- A 2024 systematic review by Hardan and colleagues combined five clinical trials of at-home and in-chair whitening and found no significant colour difference between people who restricted their diet and those who did not. The trials were small and lasted one month at most.
Why does whitening cause sensitivity, and how long does it last?
According to MouthHealthy, the peroxide in the whitener passes through the enamel to the softer dentine underneath and irritates the nerve of the tooth. The NHS says teeth may become sensitive to cold or sweet food and drink.
- How common: the ADA says mild to moderate, temporary sensitivity can affect up to two-thirds of users early in treatment; it is more common with higher concentrations of the active agent, and contact time and the use of light also play a part.
- How long: with trays or strips, the ADA says it may develop within two to three days of starting and usually resolves by the fourth day after treatment. Bristol Dental School says it resolves once whitening has stopped.
How can you manage sensitivity after whitening?
- Tell your dentist, who can change how long or how often the gel is applied. The Oral Health Foundation says your dental team can give advice or products to help.
- Use a toothpaste for sensitive teeth, as Bristol Dental School suggests. The Oral Health Foundation says these block tiny channels in the dentine: spit after brushing rather than rinsing, and at night rub a little onto the painful area and leave it on.
- Go easy on triggers such as the cold and sweet food and drink the NHS mentions.
- Pause if needed. MouthHealthy says the sensitivity is usually temporary and treatment can be delayed and tried again; agree any break with your dentist.
Prevention is less certain. The ADA says desensitising gel or painkillers taken before whitening need more research, and a 2021 systematic review by Martini and colleagues found a 12% lower risk of sensitivity when a potassium nitrate desensitiser was applied beforehand, a reduction the authors call subtle. Ask your dentist or pharmacist before taking any painkiller.
What if your gums are sore or white after whitening?
The NHS lists sore gums or throat and white patches on the gums among the side effects, which may occur for a short time even though the dentist should protect your gums. The ADA says gum irritation is usually due to poorly fitting trays or to the barrier or gel not being applied properly, and typically resolves shortly after treatment. With trays, wipe away gel near the gums, as Bristol Dental School advises; if a tray presses on your gums or no longer fits, or the irritation does not settle, see a dentist.
Will fillings, crowns and veneers change colour?
No. The Oral Health Foundation and Bristol Dental School say fillings, crowns and veneers do not whiten. The ADA notes that this can leave a colour difference, and that bleaching may reduce how strongly composite and ceramic materials bond to enamel.
This is why order matters in a smile makeover. As our smile makeover page explains, decay and gum disease are treated first, teeth are moved if needed, whitening comes next, and crowns or veneers are made last so that they match the new shade. A 2021 systematic review of laboratory studies by Savian and colleagues found that bleaching weakens the bond of adhesives to enamel and dentine for up to about two weeks, and recommends placing bonded restorations at least two weeks after bleaching; clinical trials are still needed. If you are travelling, ask how whitening, choosing the shade and fitting restorations fit into your stay; this is planned at the examination. See also smile makeover planning and mock-ups.
How do you keep the result, and can whitening be topped up?
- Brushing and cleaning: the Oral Health Foundation says good brushing and regular dental cleaning help maintain the result.
- Whitening toothpaste: MouthHealthy says it removes only surface stains and does not change the colour of teeth.
- Top-ups: Bristol Dental School says whitening may need repeating, and the Oral Health Foundation says custom trays can be kept and reused. In the UK, the General Dental Council (GDC) says products releasing 0.1% to 6% hydrogen peroxide may only be supplied through dental professionals, and the NHS warns that salon, pharmacy and online whitening does not work as well and may harm teeth and gums.
For veneers and crowns, see how long a smile makeover lasts.
What if sensitivity continues once you are home?
The GDC advises telling your own dentist before travelling for treatment, in case of later complications. Once home:
- See your dentist if the pain is severe, lasts more than a few weeks, affects only one tooth or comes on suddenly; the Oral Health Foundation says these could be signs of decay, a cracked tooth, gum problems or infection.
- Take your aftercare instructions, the copy of your treatment summary and your X-rays. It also helps to know the whitening method used and your shade before and after; if these are missing from your summary, ask before you fly.
- Send us clear photos and a short description on WhatsApp so that the next steps can be discussed; see our aftercare and follow-up page.
How is whitening aftercare handled at Rönesans?
Whitening is one of the aesthetic treatments at our clinic in Serdivan, Sakarya. The examination looks at your teeth and gums, existing fillings and crowns, and the cause of the discolouration; decay or gum disease is treated first. Plaque and surface stains are cleaned off beforehand, which at our clinic can be done with an air-polishing device that uses air, water and fine powder. Which whitening method suits you is decided at the examination, taking into account your expectations and any history of sensitivity.
If whitening is part of a smile makeover, fillings or crowns that need to match the new colour are included in the plan. We use digital smile design, and crowns are made with CAD/CAM at the dental laboratory we work with.
Before treatment starts, you know which dentist will treat you and receive a written treatment and cost plan; the cost is confirmed after the examination. Before you leave, you receive aftercare instructions, a copy of your treatment summary and copies of your X-rays, and follow-up follows a defined process. For dates and length of stay, see planning your visit.
We are open Monday to Friday 10:00–22:00 and Saturday 10:00–19:00, Türkiye time. Send photos on WhatsApp at +90 532 363 49 54, call our head office on +90 264 606 09 43 or use our contact page; during opening hours we reply in English and German within 15 minutes.