How Long Does Teeth Whitening Last?
Teeth whitening is, by far, one of the most popular and inexpensive procedures in cosmetic dentistry. Who doesn’t love wearing a bright, confident smile?
There are hundreds of teeth whitening options available today. Some are convenient for at-home use; others are only attainable by booking a dentist’s appointment. Each method is unique.
Most whitening products come in creative labels that entice doctors and patients to make a purchase. But not everything you see on a label may be accurate. It’s no fun having to wait to notice results, but watching them fade away so soon is an even bigger disappointment.
How could you have known this was going to happen?
In this article, we’ll compare common teeth whitening methods: what they entail, how long their results last, and what you can do to prevent your smile from fading prematurely.
Read on if you’re ready to get rid of the guesswork.
How Long Does At-Home Teeth Whitening Last?
At-home teeth whitening products are usually sold over-the-counter at pharmacies and multi-purpose supermarkets. Here’s a rundown of the 3 main options available:
Teeth whitening toothpaste can take a month and a half to show desired results. Yet, their effect may last up to four months. Despite the number of popular brands offering this product, you should always consult your dentist before using them.
Whitening toothpaste contains abrasive particles that wear away the enamel, so long-term use could expose your dentine and give teeth a yellow hue.
Tooth Whitening Strips
Whitening strips are one of the most fast-acting over-the-counter treatments for brightening extrinsic stains. High-quality brands can give you whiter teeth within three days and leave your smile dazzling for up to 6 months. Some versions can even resolve mild, intrinsic tooth discolorations.
But tread with caution: most gel-based whitening techniques use peroxide to brighten your teeth. And whitening strips use potent bleaching agents to achieve such rapid results. The peroxide could bleach your gums and create mouth blisters if placed incorrectly.
At-Home Teeth Bleaching Kits
By law, at-home tooth whitening kits have low concentrations of carbamide (or hydrogen) peroxide in their bleaching solution. That’s because bleaching agents could penetrate the more sensitive areas of your teeth if applied for too long.
Dentists or dental hygienists typically time your in-chair whitening session to ensure your safety. But patients who use at-home kits need to be vigilant and adhere to the directives on their bleaching package. To reduce the risks of adverse effects, organizations like the American Dental Association regulate the concentration of peroxides in these kits.
So while professional (in-office) tooth whitening procedures use up to 43% hydrogen peroxide, your home kit won’t exceed 10%. And if you live in the United Kingdom, most regulated kits have no more than 6% peroxide solution.
With such low concentrations, some patients don’t notice any changes to their tooth color after using at-home treatments. Others report improvements in the brightness of their smile, but they usually start fading within the first six months.
Of course, diet and lifestyle also influence the longevity of your results, and you might opt to repeat treatment sooner than expected.
How Long Does Professional Teeth Whitening Last?
If you’re looking for a more guided tooth whitening method, consider these two procedures:
During a microabrasion procedure, your cosmetic dentist will use a mechanical tool to scrape off the thin outer layer of your stained enamel6. They’ll then polish your teeth with an abrasive paste, rinse you out, and that’s it! There aren’t any harsh chemicals involved.
Not only is microabrasion one of the least invasive whitening techniques, but it’s also the only method to give permanent results!
In-chair Teeth Bleaching
In-chair tooth whitening allows patients to get nearly instant results from a single appointment. Zoom whitening treatments, for example, can improve your smile within one 45-minute session. Other brands achieve similar effects after an hour.
Some teeth bleaching products will create whiter results if they contain more carbamide peroxide than others, but those effects are usually short-lived. One study which compared the effectiveness of three whitening gels with different carbamide peroxide concentrations found that all three treatments gave similar whitening results after one week5. The quality of teeth whitening products depends on much more than peroxide concentrations. Dentists also need to consider factors like:
- Treatment duration;
- The type of chemical agents used; and
- The type of remineralizing agents included in the kit 1.
There isn’t enough research within the dental community to prove whether LED light improves the brightness achieved from any whitening treatment. For this reason, many dentists consider light curation as a mere marketing gimmick to boost sales for select brands. On the other hand, some specialists claim that LED-assisted whitening procedures bleach teeth much faster. So their light feature still carries some benefit.
Professional whitening could work to your advantage if you’re planning to brighten your smile for a special occasion. Studies show that at-home kits take at least two weeks to produce the teeth whitening results you’d get at the dentist’s office4; but that only happens if you stick to the treatment plan.
As we mentioned earlier, professional bleaching uses far greater concentrations of hydrogen peroxide to remove tooth discoloration. Although tooth sensitivity and gum irritation are common side effects of any whitening treatment, the risks are still lower when performed by an expert.
On average, in-chair teeth whitening could give you whiter teeth for up to three years. But that doesn’t mean your teeth will remain as bright as they were the first day after your treatment. Your brightened shade is strongest following the first year following the procedure.
Tooth whitening results fade away gradually, so most dentists offer a take-home kit as part of their package. You can use it every six months, for its prescribed time, to reduce teeth stains and restore your glow.
Similar to an at-home system, your professional kit will contain a pair of tooth whitening trays and a syringe with bleaching gel. However, these are still safer to use than store-bought versions.
For one, over-the-counter kits use one-size-fits-all models for their whitening trays. Often, these are either:
- too tight to fit over your teeth; or
- too loose and run the risk of spilling the solution over your gums.
But with a professional whitening service, dentists take impressions (or molds) of your teeth to create custom trays for your mouth.
Your care provider will also teach you how to use your whitening tray at home. Some patients believe that the more gel they use in the tray at once, the faster they’ll see results. Not only is this false, but the excess solution will ooze onto your gums and cause blisters. Patient education is crucial for proper teeth whitening aftercare, but people miss this benefit when they purchase kits on their own.
What Factors Cause Teeth Whitening to Fade?
Each form of teeth whitening has its pros and cons. While we can’t say definitively that one technique better suits your case than others, there are external factors that cause most patients’ teeth to fade faster than others. These include the following:
Certain foods contain ingredients and chemicals that stain teeth. They contain chromogen – a pigment-producing substance that adheres to the enamel. Some acidic beverages also contain tannins or compounds that help chromogens stick to your tooth enamel.
Here’s a good rule: If it stains your white shirts, it’ll likely do the same to your smile.
Keep an eye out for foods, beverages, and condiments with intense colors, such as:
- Curry (turmeric)
- Tomato sauce
- Soy sauce
- Grape juice
- Red wine
- Balsamic vinegar
- Berries (blueberries, blackberries, and cranberries especially)
Professional whitening kits contain chemicals that make teeth more porous or receptive to bleaching agents. But the effect usually lasts up to 48 hours after your treatment. As a result, you should refrain from eating the list of foods above for at least the first 2 days following your bleaching appointment. Though inedible, you should take the same precaution with colored toothpaste.
The nicotine from the tobacco in cigarettes usually seeps through the pores in your enamel and causes intrinsic stains. This happens because nicotine binds readily with oxygen particles within your tooth structure – a reaction that creates yellow and brown stains.
Nevertheless, cigarette smoking can also cause dark stains on the outer surface of your teeth. That’s why chronic smokers have typically discolored smiles.
Beware: cigarette smoking will quickly undo any efforts you make to whiten your teeth.
Poor hygiene is one of the most common causes of yellow teeth – but it’s also the most practical to reverse. Patients who neglect to do regular tooth brushing and flossing are prone to plaque and tartar buildup, which give teeth a yellow appearance.
Some people use a mixture of baking soda and hydrogen peroxide to remove the plaque and brighten their teeth. However, it’s safer to see a trained hygienist for deep dental scaling. This procedure offers double the benefit: it cleans your teeth and clears plaque from deep below your gum line to preserve your gum health.
You can also use a warm salt water rinse once daily to flush out any lingering oral bacteria after brushing. Some antiseptic mouthwashes contain chromagens (stain-producing chemicals), so dentists rarely advise you to use them for more than 2 weeks. Chlorhexidine is a notorious culprit.
Previous Dental Work
Amalgam restorations give the appearance of dark stains because of the grey to charcoal color of the mercury filling. Besides that, many specialists have discontinued using amalgam fillings due to their correlation with heavy metal poisoning. For the sake of safety and cosmetics, it would be wise to have these replaced with composite (tooth-colored) fillings2.
How to Keep Your Teeth White for Longer
Whether you choose to brighten your smile at home or a clinic, your whitening aftercare will determine the longevity of your results.
Want to make the most out of your investment? Follow these steps to maintain your pearly whites for as long as possible:
- Eat a diet rich in foods with high water content to help wash out leftover food and reduce bacterial buildup. Cucumbers, watermelon, lettuce, and zucchini contain up to 96% water.
2) Drink at least 3 liters of water daily.
- Rinse or brush after every meal. If you just ate citrus or highly acidic foods, then try brushing your teeth half an hour later to reduce the risk of enamel corrosion.
4) Abstain from cigarette smoking.
- Schedule a dental scaling every 6 months. Your dentist may suggest that you come for cleanings more frequently if you have one or more dental implants.
6) Use occasional hydrogen peroxide mouth rinses to help brighten fading teeth. Be sure to do these infrequently to avoid prolonged tooth sensitivity3.
Here’s to more years with a dazzling smile!
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Carey, C. M. (2014, June). Tooth whitening: What we now know. The journal of evidence-based dental practice. Retrieved December 12, 2021
de Freitas, M. R., de Carvalho, M. M., Liporoni, P. C. S., Fort, A. C. B., Moura, R. de M. e, & Zanatta, R. F. (1AD, January 1). Effectiveness and adverse effects of over-the-counter whitening products on dental tissues. Frontiers. Retrieved December 12, 2021
Matis, B. A., Cochran, M. A., & Eckert, G. (2009, March 1). Review of the effectiveness of various tooth whitening systems. Operative Dentistry. Retrieved December 12, 2021
Meireles, S. S., Fontes, S. T., Coimbra, L. A. A., Bona, Á. D., & Demarco, F. F. (2012, April 1). Effectiveness of different carbamide peroxide concentrations used for tooth bleaching: An in vitro study. Journal of Applied Oral Science. Retrieved December 12, 2021
Pini, N. I. P., Sundfeld-Neto, D., Aguiar, F. H. B., Sundfeld, R. H., Martins, L. R. M., Lovadino, J. R., & Lima, D. A. N. L. (2015, January 16). Enamel microabrasion: An overview of clinical and scientific considerations. World journal of clinical cases. Retrieved December 12, 2021