한국어 
简体中文 WHITENING
Teeth Whitening
The method and result depend on the cause of discoloration. We first check for cavities and gum problems, then proceed without overdoing it.
Dr. Jeong Jinwoo (board-certified prosthodontist · specialist in integrated dentistry) · written and reviewed · last reviewed
The short answer
Does whitening make everyone’s teeth white?
No. Surface stains from coffee, tea or tobacco and the general yellowing that comes with age respond well to whitening, but internal discoloration formed through medication or during tooth development responds only partially, and a single tooth that has darkened because its nerve died needs a different method. Crowns, veneers and resin fillings do not whiten. So before whitening we first check the cause of discoloration, and if it is only surface staining, we recommend scaling instead.
Whitening is a conservative aesthetic treatment that does not grind the teeth. However, its effect is not permanent and sensitivity is common, so Joy Dental Clinic Bongcheon sets a target shade and does not push beyond it.
In-office whitening
At the clinic, the gums are protected and a high-concentration whitening agent is applied, with a dedicated light used to speed the reaction. Suitable when you want to see a change in a short time.
At-home whitening
An impression is taken to make custom trays, and you wear a low-concentration whitening agent at home for set periods. The shade rises gradually, and sensitivity is easier to manage.
Combined whitening
Starting with in-office whitening and maintaining with at-home whitening; considered when discoloration is marked or you want the result to last longer.
How does teeth whitening proceed?
- Checking the cause of discoloration. We distinguish whether it is staining on the surface from coffee, tea or tobacco, internal discoloration where the tooth itself is yellow or dark, or a single tooth that has changed color (nerve death). Depending on the cause, whitening may or may not be effective. See types of tooth discoloration (Korean).
- Checking for cavities, gum problems and cracks. If there are cavities, gum inflammation, cracks or exposed roots, the whitening agent can irritate them, increasing pain or affecting the nerve. We check first with Q-ray and X-rays, and if there is a problem, whiten after treating it.
- Recording the current shade and explaining the goal. The current shade is recorded with a shade guide (Korean) and photos are taken. We explain that crowns or resin on the front teeth will not whiten and may create a color difference, as well as the expected range of change and how long it lasts.
- Scaling and polishing. Surface stains and tartar must be removed first so the whitening agent reaches the teeth evenly. When there is only staining, some people are satisfied with this step alone.
- Whitening. In-office whitening applies a high-concentration hydrogen peroxide–based agent after a gum protector is applied, and a light speeds the reaction (30–60 minutes per session). At-home whitening uses custom trays filled with a low-concentration agent, worn for set hours a day for 2–4 weeks. The literature concludes that the final results of the two methods are similar[1]; they differ in speed and in how sensitivity is managed.
- Managing sensitivity and maintenance. For 24–48 hours after whitening, avoid strongly colored foods and drinks and smoking. If there is sensitivity, desensitizing agents and fluoride are used and the interval is adjusted. We explain sensitivity after whitening (Korean) and a maintenance whitening plan together.
How does the effect of whitening differ with the cause of discoloration?
Whitening agents work by passing through the tooth and oxidizing pigment molecules.[2] So the result depends on where the pigment is and in what form.
| Cause | Approach | Whitening effect |
|---|---|---|
| Surface stains (coffee, tea, tobacco, wine) | Mostly removed by scaling and polishing, then whitening to go lighter than the original shade | Good |
| Aging, general yellowing | In-office or at-home whitening, or both | Good (varies by individual) |
| Internal discoloration (tetracycline, excess fluoride, etc.) | Partial improvement with long-term at-home whitening; banded discoloration has limits → laminate veneers or crowns considered | Limited |
| A single tooth darkened (nerve death) | Whitening from inside the tooth after root canal treatment (non-vital whitening); if that fails, a prosthesis | A different method |
| Discolored resin or prostheses | Does not whiten → replacement | Not applicable |
| White spots (demineralization, fluorosis) | Whitening may make the spots more noticeable → check the cause, then consider resin restoration, etc. | Caution |
* A general classification; the actual effect is explained individually after diagnosis.
In-office, at-home and combined whitening: what is the difference?
| Item | In-office whitening | At-home whitening | Combined |
|---|---|---|---|
| Where | Dental clinic | At home | Clinic + home |
| Agent concentration | High (hydrogen peroxide 25–40%) | Low (carbamide peroxide 10–16%) | High, then low |
| Period | 1–3 visits | Worn daily for 2–4 weeks | Visits, then a maintenance period |
| Sensitivity | Relatively common, short-term | Less, and easier to control | Moderate |
| Features | See change in a short time | Gradual, easy to maintain | Range of change and maintenance together |
| Health insurance | Not covered | Not covered | Not covered |
* A general comparison; an accurate diagnosis and costs are given individually at the consultation. — As of September 2026
How is the cost determined?
- Method — The make-up differs for in-office whitening (per session), at-home whitening (trays + whitening agent) and combined whitening.
- Sessions · period — The number of in-office sessions and the length of at-home whitening depend on the difference between the target shade and the current shade.
- Prior treatment — Scaling (covered once a year from age 19) and any cavity or gum treatment needed are separate.
- Maintenance whitening — When the color returns, there is a cost for partial maintenance whitening.
Teeth whitening is for aesthetic purposes and is a non-covered item not covered by Korean national health insurance. Scaling before whitening (once a year from age 19) and any necessary cavity or gum treatment are covered items. After diagnosis, we explain item by item according to the method and number of sessions, and we do not run discounts or promotional prices.
When we do not recommend whitening, or the order is different
- · When there are crowns or resin on the front teeth — prostheses do not whiten, so a color difference appears after whitening. We decide the order together with a plan for replacing the prostheses, or approach it with aesthetic prosthodontics.
- · When the discoloration comes from inside the tooth (nerve damage, medication) — non-vital whitening, laminate veneers or crowns are considered.
- · If the goal is removing stains — scaling and professional cleaning are sometimes enough, so we do not recommend whitening.
- · When there are cavities, gum inflammation, cracks or severe sensitivity — these are treated first, and then whitening is done.
- · During pregnancy or breastfeeding, or under age 18 — safety data are insufficient, so we postpone it.
- · Teeth with white spots — whitening can make the spots more noticeable, so other methods are considered first.
Nothing hidden
Side effects and limits of whitening
Sensitivity. The whitening agent can stimulate the nerve through the dentin, causing sensitivity to cold during or right after whitening. It is the most common side effect and usually subsides within a few days.[2] It is managed with desensitizing agents, fluoride and adjusting the interval, and stopped if severe.
Gum irritation. If a high-concentration agent touches the gums, they may turn white and sting. A gum protector prevents this, and if it happens it usually recovers within a day.
Color returns. The effect of whitening is not permanent. Depending on diet and smoking, teeth gradually return to their original color over 6 months to 2 years, and maintenance whitening is needed.[3]
Uneven results. Each tooth may lighten differently, and the neck of the tooth tends to lighten less. Crowns and resin stay the same, so color differences may show.
Over-whitening. Repeating it excessively can make teeth look bluish or translucent and prolong sensitivity. We set a target shade and do not recommend going beyond it.
Effect on enamel. Evidence that whitening agents used as directed significantly damage enamel is weak[3], but for 24 hours right after whitening the surface is vulnerable to acidic drinks and staining, so take care.
FAQ
Frequently asked questions
Q1 Does whitening make teeth sensitive?
Because of the nature of the whitening agent, sensitivity can occur, and it is mostly temporary. We reduce the burden by adjusting the concentration and using desensitizers; the degree varies from person to person. If it is severe, we stop and leave an interval.
Q2 How much whiter will my teeth get?
It varies greatly between individuals, but in-office whitening usually lightens teeth by 2–3 shades on a shade guide. It depends on the original color, the cause of discoloration and age, and the effect on internal discoloration is limited. At the consultation we show you the current shade and the expected range.
Q3 How long does the effect last?
It varies widely, from 6 months to 2 years, depending on diet (coffee, tea, smoking, etc.) and care. When the color returns, partial re-whitening can maintain the shade.
Q4 Which works better, in-office or at-home whitening?
Several studies conclude that the final results are similar. In-office whitening is faster, while at-home whitening is gradual and sensitivity is easier to control. Choose according to your schedule and sensitivity.
Q5 Will crowns or fillings also lighten?
Whitening works only on natural teeth; artificial materials such as crowns, laminate veneers and resin do not change color. If there are prostheses on the front teeth, we plan the order taking into account the color difference after whitening.
Q6 Is anything checked before whitening?
Cavities, gum inflammation, cracks or exposed roots can increase irritation during whitening, so we check for them first. If the cause of discoloration is internal, whitening alone has limits, so we also explain other methods.
Q7 Can scaling alone make teeth whiter?
Scaling and professional cleaning remove surface stains so the teeth return closer to their original color. This is different from whitening, which lightens the shade of the tooth itself; if staining is the main cause, cleaning alone may be enough.
Q8 Does whitening damage teeth?
Evidence that whitening agents used as directed significantly damage enamel is weak. However, repeating it excessively can prolong sensitivity and make teeth look translucent, so we do not recommend going beyond the target shade.
Q9 What should I be careful about after whitening?
For 24–48 hours, avoid strongly colored foods such as coffee, tea, wine, kimchi and curry, and smoking, and cut down on acidic drinks. Afterward, rinsing with water after strongly colored drinks helps maintain the result.
Q10 Does health insurance cover teeth whitening?
Whitening is for aesthetic purposes, so it is not covered. Scaling before whitening is covered once a year from age 19, and if cavity or gum treatment is needed, those items are covered.
Q11 I stopped treatment partway at another clinic. Can you continue it?
Yes. We check the state of the previous treatment carefully and then continue. We assess your current condition with a detailed diagnosis and draw up a new plan for the remaining treatment.
References
- de Geus JL, Wambier LM, Kossatz S, Loguercio AD, Reis A. At-home vs In-office Bleaching: A Systematic Review and Meta-analysis. Oper Dent. 2016;41(4):341-356. — No significant difference in color change between at-home and in-office whitening; similar risk of sensitivity.
- Kwon SR, Wertz PW. Review of the Mechanism of Tooth Whitening. J Esthet Restor Dent. 2015;27(5):240-257. — Hydrogen peroxide passes through enamel and dentin and oxidizes pigment molecules; sensitivity results from nerve stimulation via dentin penetration.
- Carey CM. Tooth whitening: what we now know. J Evid Based Dent Pract. 2014;14 Suppl:70-76. — Safety of whitening agents used as directed; sensitivity and gum irritation are temporary, and the effect decreases over time, so maintenance whitening is needed.
RESERVATION
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33 m from Exit 1, Bongcheon Station (Line 2) · Directions from Bongcheon Station →
This page was written and reviewed by Director Jeong Jinwoo (board-certified prosthodontist and specialist in integrated dentistry) of Joy Dental Clinic Bongcheon, based on standard dental knowledge and the literature above. It is intended as general information; individual treatment plans and costs are given after a detailed diagnosis and consultation.
Last updated: 2026-09-11