Short answer: Teeth whitening (bleaching) is a procedure that lightens the color pigments inside the tooth using gels containing hydrogen peroxide or carbamide peroxide. There are in-office methods applied at the clinic in a single session and at-home methods carried out over a few weeks with custom trays. It works on natural teeth and does not change the color of fillings or crowns. Temporary sensitivity may occur; how long the result lasts depends on diet and oral care habits.
Tooth color is one of the most noticeable features of a smile. Over time, teeth can turn yellow or dull due to coffee, tea, smoking, certain foods and age. Teeth whitening is a cosmetic procedure used to lighten these color changes and is considered safe when performed under a dentist's supervision. In this guide we look in detail at how whitening works, which methods are available, who it is suitable for and how long the results can last.
What is teeth whitening?
Teeth whitening (bleaching) is a procedure in which peroxide-based gels applied to the tooth surface penetrate the enamel, break down the color pigments in the inner layers of the tooth and bring the tooth to a lighter shade. The active ingredients used are usually hydrogen peroxide or carbamide peroxide, which turns into hydrogen peroxide in the body.
Whitening should be distinguished from dental cleaning. Scaling and polishing remove stains and deposits from the tooth surface, bringing the tooth closer to its own natural color. Whitening, on the other hand, aims to lighten the natural color of the tooth itself. That is why a dental cleaning is recommended before whitening in most cases.
Tooth discoloration falls into two main groups:
- Extrinsic discoloration: Stains left on the surface by tea, coffee, red wine, smoking and certain foods. They usually respond well to cleaning and whitening.
- Intrinsic discoloration: Age-related darkening, color changes after trauma, and stains caused by certain medications taken during tooth development or by excessive fluoride intake. In this kind of discoloration, the effect of whitening may be more limited and different treatments may be needed.
What is the difference between in-office and at-home whitening?
Teeth whitening methods fall into two main categories: in-office whitening applied by the dentist at the clinic in a single session, and at-home whitening carried out over a few weeks with custom trays. Both methods are effective when applied correctly; they differ in duration, concentration and how they are applied.
In-office whitening
It is performed at the clinic using a higher-concentration whitening gel. Before the procedure, the gums are covered with a special barrier to protect them from contact with the gel. The gel is applied to the teeth and renewed at set intervals. Some systems also use a light source. A session usually takes about an hour, and the color change is noticeable after the first session. Several sessions can be planned if necessary.
At-home whitening
The dentist takes impressions of the patient's teeth and has thin, clear custom trays made. The patient places a low-concentration whitening gel into these trays and wears them for the time recommended by the dentist, usually a few hours a day or overnight. Treatment generally lasts 2–3 weeks. The effect appears more gradually, and the risk of sensitivity is usually lower.
Combined treatment and store-bought products
For some patients, treatment can begin with an in-office session and continue with at-home application. Whitening toothpastes and strips sold in stores, on the other hand, are mostly low in effect or aimed only at surface stains. Because careless and prolonged use can lead to enamel wear and gum irritation, it is recommended that whitening be done under a dentist's supervision. Regulations in Europe and in Türkiye also require that high-concentration products be applied only by a dentist or used under a dentist's supervision.
Who can have teeth whitening?
Teeth whitening can be performed on adults with healthy teeth and gums who are bothered by yellowing or darkening of their teeth. Before the procedure, an oral examination is carried out to determine whether whitening is suitable and what a realistic expected result would be.
Situations that require careful evaluation or in which postponing whitening is recommended:
- Untreated cavities and gum disease: These problems need to be treated first.
- Pregnancy and breastfeeding: Cosmetic whitening is generally postponed during these periods.
- Under 18: Whitening is generally not recommended for teenagers; in special cases a dentist's evaluation is required.
- Pronounced tooth sensitivity and gum recession: Sensitivity may increase in people with exposed root surfaces.
- Fillings, crowns or veneers on the front teeth: Whitening does not change the color of these restorations; since a color mismatch may occur afterward, planning should be done in advance.
For a single tooth that has had root canal treatment and darkened on its own, a different whitening method performed from inside the tooth may be considered. For people undergoing orthodontic treatment, whitening is generally planned after the treatment is completed.
What are the sensitivity and side effects?
The most common side effect of teeth whitening is temporary tooth sensitivity, which goes away on its own within a few days in most patients. Sensitivity is felt as a brief twinge, especially with cold drinks and exposure to air.
Other possible side effects:
- Mild, temporary gum irritation due to the gel touching the gums
- Gum burns from ill-fitting trays or overuse
- A color difference between restorations and natural teeth
Tips that can help reduce sensitivity:
- Using the desensitizing toothpastes or gels recommended by your dentist before and after the procedure
- Following the recommended time and amount of gel for at-home whitening, and taking a break of a day or two if necessary
- Avoiding very hot and very cold foods and drinks in the first days
Scientific studies support that whitening performed under a dentist's supervision at the recommended concentrations does not cause permanent damage to tooth enamel.
How long does whitening last, and how should you care for your teeth?
The effect of teeth whitening is not permanent; however, with proper care and habits, the result can often be maintained for a long time. How long the color change lasts depends on the person's diet, smoking and oral hygiene.
To maintain the result:
- Take care in the first 48 hours: Right after whitening, teeth are more susceptible to staining substances. During this time, it is advisable to avoid tea, coffee, cola, red wine, tomato paste and dark sauces.
- Smoking: Smoking quickly reduces the effect of whitening; quitting benefits both tooth color and overall oral health.
- Using a straw: Drinking colored beverages through a straw can reduce their contact with the front teeth.
- Regular cleaning: Brushing twice a day, flossing, and a checkup with scaling every 6 months prevent surface stains from building up.
- Touch-ups: On your dentist's recommendation, short touch-up applications with at-home trays can be done at certain intervals.
What factors affect the cost of teeth whitening?
The cost of teeth whitening varies depending on the method chosen (in-office, at-home or combined), the number of sessions required, whether custom trays will be made, and whether additional procedures such as a dental cleaning or cavity treatment are needed beforehand. Internal whitening of a single tooth and whitening of all the teeth are also planned differently. For this reason, cost information specific to you is provided in writing after the examination and planning. For your other questions about whitening, you can visit our frequently asked questions page.
When should you have your tooth color evaluated in Ankara?
If you are not happy with the color of your teeth, have noticed a distinct darkening in a single tooth, or have experienced sensitivity with store-bought products, a good starting point is to have your teeth and gums checked to make sure they are healthy. At our polyclinic in Park Oran Ofis in Çankaya, we evaluate the cause of the discoloration and discuss with you the whitening method suitable for you and a realistic expected result. To make an appointment, you can visit our contact page.
Frequently asked questions
Does teeth whitening damage the teeth?
Scientific studies support that whitening performed under a dentist's supervision at the recommended concentrations does not cause permanent damage to tooth enamel. The most common side effect is sensitivity, which usually goes away within a few days.
Does whitening change the color of fillings and crowns?
No, whitening only works on natural tooth tissue. If there are fillings or crowns on the front teeth, these restorations may need to be replaced after whitening to match the color.
How long does teeth whitening last?
The effect is not permanent but can be maintained for a long time with proper care. The duration varies from person to person depending on smoking, tea and coffee consumption and oral hygiene; touch-up applications can be done if needed.
What should you not eat after whitening?
For the first 48 hours, it is advisable to avoid staining foods and drinks such as tea, coffee, cola, red wine, tomato paste and dark sauces, and not to smoke.
