What are the differences between types of teeth whitening?
Teeth whitening is divided by where it is done, the concentration of the agent, and how long it is done. Comparing it together with over-the-counter self-whitening looks like this.
| Category | In-office whitening | At-home whitening | Non-vital tooth whitening | Over-the-counter self-whitening |
|---|---|---|---|---|
| Where it is done | Dental clinic | Home (with trays made at the dental clinic) | Dental clinic | Home |
| Agent | High-concentration hydrogen peroxide | Low-concentration agent | Agent placed inside the tooth | Limited to a low concentration |
| Duration | About 1 hour per session, multiple sessions if needed | 1–2 hours a day (overnight for some agents), for 2–4 weeks | 1–4 times, a few days to 1 week apart | Varies by product |
| Advantages | Fast | Brightens evenly and is easy to maintain | Brightens just the one darkened tooth | Cheap and convenient |
| Disadvantages | Sensitivity can occur | Must be done consistently | Only possible for teeth that have had root canal treatment | Weak effect, and can irritate the gums if misused |
| Wonjin Dental | ₩110,000 per session | ₩250,000 per arch | ₩100,000 (retouch included) | - |
Prices are as of September 2026, VAT included (cosmetic treatment). Check prices for combinations on all treatment fees.
How is teeth whitening done at the clinic and at home?
In-office whitening is done at the dental clinic by protecting the gums and then applying a high-concentration agent, and each session takes about 1 hour. The usual order is as follows.
- Exam and recording the current color: checking for cavities, cracked teeth, the gums, and where restorations are
- Cleaning the surface with scaling or stain removal if needed
- Protecting the lips and gums
- Applying the agent and leaving it for about 15–20 minutes (with light, depending on the method)
- After repeating 2–3 times, wiping off the agent and checking the color
For 1–2 days right after whitening, the teeth may feel sensitive or the gum edges may sting. During this period, it is best to avoid things that stain, such as coffee, curry, red wine, and cigarettes.
At-home whitening is a method where the dental clinic takes an impression to make trays that fit your teeth exactly, and you put the agent you received from the clinic into them and wear them at home. It is usually done for 1–2 hours a day (overnight for some agents) for 2–4 weeks. The teeth brighten slowly and evenly, and because the trays can be reused, it is also good for maintenance after in-office whitening.
Over-the-counter strips, pens, and whitening toothpastes, commonly called self-whitening, have low concentrations and often only lighten surface stains. Many whitening toothpastes work by polishing off surface stains with abrasives, so using them too often and too hard can wear down the tooth surface. Over-the-counter products are explained in the article how well over-the-counter whitening products work.
How are teeth that have had root canal treatment whitened?
If a tooth that has had root canal treatment has darkened to gray or brown, whitening from the outside does not brighten it well, so non-vital whitening is done from the inside. A small opening is made at the back of the tooth, the agent is placed inside, and it is temporarily sealed; then the agent is changed every few days to 1 week, repeating until the desired color is reached.
If the root canal treatment is in poor condition, redoing the root canal treatment may come first. The tooth can darken again over time, and in rare cases resorption, where the outside of the tooth root dissolves, has been reported, so we keep monitoring afterward. If whitening does not give the color you want, we consider Brinate or a crown.
Which teeth cannot be whitened?
Whitening agents only work on natural teeth, so in the following cases there is no effect, or another treatment comes before whitening.
- Crowns, porcelain veneers, composite fillings: their color does not change, so there may be a color difference after whitening
- Teeth with severe antibiotic (tetracycline) staining: band-shaped discoloration does not come out easily
- White spots caused by too much fluoride: the spots remain as they are
- Cavities, cracked teeth, gum inflammation: these must be treated first
- Teeth with receded gums and exposed roots, or teeth that were already very sensitive: sensitivity may get worse
- During pregnancy or breastfeeding, or for growing adolescents: postpone or decide carefully
How much brighter the teeth will get depends on the original color and the cause of discoloration. For expectations, see the article how much brighter teeth get with in-office whitening.
How we handle it at Wonjin Dental
Wonjin Dental offers in-office whitening, at-home whitening (trays and gel), and non-vital tooth whitening. The non-vital whitening fee includes a retouch, so if the tooth darkens again, it can be touched up. For people with heavy staining, stain removal (₩100,000) is sometimes done first. Wonjin Dental is right by Gangnam Station Exit 1.
Frequently asked questions
Can I do in-office whitening and at-home whitening together?
Yes, you can do both. If the teeth are brightened at the clinic first and then maintained at home with trays, it is easier to keep the color longer than with just one method. If there is sensitivity, we adjust the interval.
Does whitening damage teeth?
When done according to the set method, it is known not to dissolve or weaken teeth. However, temporary sensitivity and gum irritation can occur, and they get worse if whitening is done too often or with too much agent.
When can I eat normally after whitening?
It is usually recommended to avoid coffee, tea, curry, red wine, cola, and cigarettes for 1–2 days after whitening. After that period you can eat and drink as usual, but rinsing with water after drinking staining beverages helps keep the color longer.
Can whitening toothpaste alone make teeth whiter?
Whitening toothpaste helps reduce surface stains from coffee or cigarettes. However, it is hard for it to change the color inside the tooth, and using products with a lot of abrasives hard for a long time can wear down the surface.
