Does at-home teeth whitening work?
It works a little on surface stains. Over-the-counter whitening strips, pens, and rinses have a lower concentration than in-clinic whitening, and they stay in contact with the teeth for a shorter time. So stains sitting on the surface, such as from coffee, wine, tea, or smoking, may fade, but how much and how quickly varies by product. I don't recommend or compare specific products in this article.
Even faded stains come back within a few weeks to a few months if you don't keep up the care, and faster if you drink coffee or tea often. At-home products are not free of side effects either — gum irritation and sensitivity can also occur with them.
How is it different from in-clinic whitening?
The principle is the same; the concentration, time, and how closely it adheres are different. Both use peroxide-based agents to break down the molecules that create color. The difference is how concentrated the agent is, how long it stays, and how well it stays on the teeth.
| Category | At-home whitening (strips, pens, rinses) | In-clinic whitening |
|---|---|---|
| Concentration | Low | High (managed by the dental clinic) |
| How it contacts the teeth | Briefly, via strips or pens | Applied with the gums protected, or with custom trays |
| Surface stains | Fade a little | Fade (stain removal is sometimes done first) |
| Inner tooth (dentin) color | Hard to lighten | Lightens |
| Composite fillings and restorations | No change | No change |
If the tray doesn't fit the teeth, the agent flows onto the gums and less of it reaches the teeth. The effect gets weaker and gum irritation increases.
What colors can't at-home whitening fix?
Dentin color that has deepened with age, discoloration of a tooth that has had root canal treatment, and band-shaped discoloration caused by medication in childhood are inner tooth colors, so at-home whitening can't reach them. If only one tooth that has had root canal treatment is dark, that tooth won't follow along even if the rest are lightened. If there are white spots on the teeth, the spots can actually become more noticeable after whitening.
The agent has no effect on composite fillings, crowns, or veneers. The longer you whiten, the more only the natural teeth lighten, and the bigger the difference from the filled areas. I covered this in Does whitening also lighten composite fillings or crowns?.
What should I do if my teeth get sensitive or my gums get sore during at-home whitening?
Stop right away. The agent temporarily makes the dentinal tubules sensitive, so teeth that are already sensitive or have receded gums with exposed roots can hurt more. Raising the concentration or increasing the number of sessions only increases the pain, not the effect.
If the agent stays on the gums for a long time, they can turn white from a burn or sting. This is especially true if a strip covers the gums or a rinse is held in the mouth for a long time. I wrote about how long sensitivity lasts in Sensitivity after teeth whitening.
How we do it at Wonjin Dental
If there are only surface stains, I start with scaling and stain removal. Once the removable color is cleared away, it becomes clear whether the remaining color is the tooth's inner color. Then I proceed with teeth whitening, either in-office whitening or at-home whitening using custom trays.
| Treatment | Price |
|---|---|
| Scaling not covered by insurance (insurance covers scaling once a year) | ₩60,000 |
| Stain removal | ₩100,000 |
| Professional whitening, 1 session | ₩110,000 |
| Professional whitening, 3 sessions | ₩330,000 |
| At-home whitening (tray + gel), per arch | ₩250,000 |
As of September 2026; cosmetic treatment (whitening) items include VAT. You can see all prices in the full fee list. While you are getting in-clinic whitening, don't use the products you were using at home at the same time. They irritate the same teeth on top of each other.
Frequently asked questions
Does whitening toothpaste work?
Whitening toothpaste mainly scrubs off surface stains with abrasives, so it can't change the tooth's inner color. Using a highly abrasive product with force can wear down the neck of the tooth.
How often can I do at-home whitening?
The basic rule is to follow the period and frequency of use in the product instructions. If sensitivity or gum irritation develops, stop regardless of how many sessions you've done.
Can I use at-home products to maintain results after in-clinic whitening?
Once sensitivity has completely settled, you can use them to manage surface stains, but they can't replace in-clinic whitening. For maintenance, brushing, regular scaling, and cutting down on strongly staining foods are more important.
