Tooth color, like eye or hair color, is unique to each individual. The ratio of elements in the tooth, the thickness of the enamel layer, and the density of the dentin layer determine the color of the tooth. With age, changes in the tooth’s mineral composition can cause teeth to darken. Excessive consumption of staining substances such as tea, coffee, and tobacco can also cause external discoloration of teeth over time.
For whitening to be effective, a clean tooth surface is necessary. Therefore, a professional cleaning to remove tartar should be done before whitening. After cleaning, whitening can be applied by two methods or a combination of them.
In-Office Whitening: After isolating the gums, a high-concentration whitening agent is applied to the tooth surface and activated with a laser or light source. The procedure takes about an hour and provides fast and effective whitening.
At-Home Whitening: Custom whitening trays prepared by your dentist are used. A specific amount of whitening gel is placed in the tray and worn for 4–6 hours per day for 1–3 weeks.
Teeth that have lost vitality or undergone root canal treatment may darken over time. In such cases, the whitening agent is placed inside the tooth after proper isolation, and the procedure is repeated every two days until the desired color is achieved.
After whitening, avoiding staining foods and beverages is necessary to maintain the achieved whiteness.
Contrary to popular belief, whitening performed under dentist supervision does not harm the teeth or surrounding tissues.
Your dentist will first determine the cause of discoloration and create an appropriate treatment plan to choose the most suitable whitening option.
Types of Tooth Whitening:
There are four main methods:
- At-home whitening
- In-office (clinical) whitening
- Single-tooth whitening (internal whitening)
- Combined whitening (office + home)
Which is the most effective?
Your dentist will decide after examining your teeth.
How is at-home whitening done?
Custom trays are made from impressions of your teeth. Whitening gel (10–15% carbamide peroxide) is applied inside the tray.
Duration of at-home whitening:
The trays are worn 4–6 hours per day for 10–15 days on average.
Gel application precautions:
Do not overfill the tray, as excess gel can irritate the gums. If irritation occurs, rinse immediately and apply a cream containing vitamin E.
What is in-office whitening?
Performed in a clinic, suitable for patients with time constraints. The whitening gel applied by the dentist is activated using UV light or laser. Whitening typically takes about one hour. Also called laser tooth whitening.
What is combined whitening?
A method combining both office and at-home whitening. After the office procedure, home whitening is used for 2–3 days to support results.
What is single-tooth whitening (internal)?
Used for teeth that darken after root canal treatment. The filling is removed, whitening gel is placed in the cavity, and the tooth is sealed with a temporary filling. Sessions are repeated until the desired color is achieved.
Is internal whitening harmful?
If the root canal filling is properly isolated, it is safe.
Side effects of whitening:
Except for non-vital teeth (root canal-treated), whitening may cause temporary sensitivity to hot, cold, or air. Usually, sensitivity subsides within 24–48 hours. Contact your dentist if unexpected reactions occur.
Causes of tooth discoloration:
- Physiological discoloration over a lifetime
- Discoloration from amalgam fillings
- Antibiotic use in infancy
- Discoloration from root canal treatment
- Surface stains from coffee, tea, tobacco, red wine, or long-term mouthwash use
- Discoloration from trauma causing death of the tooth’s pulp
How does whitening work?
Whitening removes colored organic and inorganic substances in the porous enamel using whitening gels (carbamide peroxide).
How long does whitening take?
Results vary by individual. On average, whitening takes 2–3 hours across two appointments spaced 3–4 days apart. Teeth with mild yellowing respond more effectively than grayish discoloration caused by antibiotics.
Do I need to clean the whitening tray?
Yes. Wash trays with liquid soap, rinse thoroughly, and store in the provided case once dry.
Is whitening permanent?
Color gradually returns over time. The duration depends on consumption of staining substances and smoking, typically 6 months to 1 year. Touch-ups every 4–6 months help maintain results.
Precautions during whitening:
Avoid colored beverages (tea, coffee, wine, cola) and tobacco. Exposure may reverse results and cause re-staining.
Does whitening harm teeth?
Whitening under dentist supervision is safe and causes no harm.
What is laser tooth whitening?
Laser is used to activate the whitening agent on enamel and shorten treatment time.