Teeth Whitening FAQ


Do at-home teeth whitening products really work?

Many people don’t know if at-home whitening products actually work because those haven’t been around for that long. But at-home whitening kits use the same products that dentists use to whiten teeth, only their active ingredients are at a lower concentration for safety purposes. That means that you can achieve almost the same level of whitening at-home than with the help of a dentist, but, within a different timescale. Instead of needing a single treatment, you will need several applications at home to get the same results. This also depends on which method is used as they all have different capacities to whiten.

What is the best teeth whitening method?

Each whitening method works on a different level and has its own advantages. If we speak in terms of results, the method that can whiten your teeth the most would probably be the gel method used with tray, followed closely by the strips method. They both can have a strong whitening agent to work the stains in-depth, and they both come in contact with teeth for a good amount of time. Those are the winning factors to get whiter teeth.

What stains teeth?

Teeth have naturally a slightly yellowish color because the transparency of the enamel lets the yellow dentin show through. When you add day-to-day habits such as drinking red wine, coffee, sodas, or smoking, the color of teeth can become yellowed or grayer overtime. These stains can affect either the inside of the tooth or the outside of the tooth. Both kinds of stains will need a different approach to whitening.

Who can have their teeth whitened?

Generally, adults over the age of 16 whose mouths are generally healthy with no gum disease and no previously restored teeth.

Who cannot have their teeth whitened?

Teens and children under the age of 16. Waiting until after the age of 16 ensures that all the adult teeth are completely in place before whitening is done. Plus, the nerve of the teeth is larger until the age of 16. Whitening teeth before this age could irritate the nerve of the tooth and cause long term sensitivity.

Pregnant or lactating women. There is no evidence to date that shows that tooth whitening procedures are harmful to an unborn or nursing child, but there’s no evidence that shows it isn’t harmful either. Exposure to large amounts of peroxides is not healthy for non-pregnant or lactating women, so it’s really up to a person’s discretion and choice. But, to be completely safe, it’s probably best to put off whitening until after the baby is weaned since it is an elective dental procedure.

Those with artificial restorations. Those who decide to have only their non-restored teeth whitened will find that they have some teeth that are whiter than others. Tooth-colored (composite) fillings, veneers, bonding, and porcelain (crowns, bridges) will not whiten.

Those wearing braces. Whitening will only work on the portion of teeth that are not covered by the metal brackets. There is also the chance that the oxidation process that whitens teeth will also affect the metal of the braces.

Those with a history of tooth sensitivity. There is a chance that the oxidation process that whitens teeth may also cause temporary tooth sensitivity. It is recommended that people with a history of tooth sensitivity caused by gum recession (exposed roots), worn enamel, and untreated cavities, should not undergo a whitening treatment, either in-office or at-home.

How long does it take to whiten teeth?

The length of time to see results depends on the concentration and type of whitening ingredients, the amount of time the whitening agent comes in contact with the enamel, and the initial color of the teeth being treated. With those factors taken into account, you may start to see results within a few days, and get full results in a timescale ranging from 1 to 4 weeks. Dental chair treatments will usually yield results within about an hour.

What results can I expect?

The exact results depend upon the concentration and type of whitening agent, the length of each whitening application, the duration of the treatment, and the kind and depth of stains being treated.

In-office whitening treatments claim to whiten up to 8 shades. At-home methods such as whitening gels and strips can whiten up to 6 shades. As for toothpaste, gums and mouth rinses, they may whiten up to 2 shades.

How long will the results last?

With proper oral health care in between whitening treatments and reducing teeth-staining habits, results from external whitening treatments can last up to 2 years. Internal bleaching results can also last for many years, and new dental technologies are producing results that last even longer.

What can affect the results of teeth whitening treatments?

Many factors can affect the results. We have written an extensive section about the subject in the Learn section.

Does teeth whitening cause sensitivity?

About two-thirds of people who whiten their teeth, whether in-office with do-it-yourself kits or natural remedies experience some form of tooth sensitivity early on in the whitening process but it dissipates within a few days.

Those who have naturally thinner enamel or more porous enamel need to be aware of the possibility of sensitivity associated with this treatment. When whitening is done in-office, dentists and dental assistants will monitor patients’ sensitivity levels during the procedure particularly if there is a patient history of tooth sensitivity.

Sensitivity can be reduced by using a high-fluoride toothpaste afterward, or by applying a high-fluoride gel product following treatment. These will help the enamel remineralize and ease sensitivity symptoms.

What can be the secondary effects of teeth whitening?

There are other possible effects of teeth whitening besides sensitivity. These include:

  • Bleached spots, which are calcium deposits that reacted to the whitening process (will settle to a more normal color after a few days).
  • Burning or irritation of the gums, inside the lip and cheek due to contact with the whitening/bleaching agent.
  • Over bright teeth or worn down gums due to overuse of whitening products.
  • Etching of enamel due to eating acidic food/drink or brushing weakened enamel too soon or too hard following whitening treatments.

Can teeth whitening damage my teeth?

Teeth whitening happens because bleaching ingredients (eg: hydrogen peroxide) temporarily broaden the gaps between the individual mineral matrix rod structure that makes up enamel so that the stains can be addressed. Until this matrix has a chance to strengthen again over the course of a few days, enamel can become etched from chewing crunchy foods, damaged or re-stained by the things we do, eat or drink. But the whitening treatment itself does not damage the teeth.

The only exceptions are the whitening products using chlorine dioxide as an active ingredient. Those have a reputation for being hard on teeth and weakening the enamel over time. This is the reason why they have been banned in the UK.

How much does teeth whitening cost?

At-home whitening kits are not very expensive. Whitening strips and gel-and-tray kits can cost $20-75 depending on the brand and how many applications are included. Pens and paint-on gels cost about $20-50.

In-office whitening treatments cost can vary greatly, ranging between $300 and $1000.

Natural or non-whitening kit remedies usually cost the least with baking soda, and vinegar, costing a few dollars. Even the 3% hydrogen peroxide that you can buy in drug stores to clean scraped knees, which can be mixed with water and swished around your mouth costs about $2. Some other whitening efforts such as coconut oil pulling may cost more.

Is teeth whitening covered by insurance?

Teeth whitening is considered a cosmetic procedure and, therefore, elective treatment and is not covered by most insurance companies, though the treatment may be claimed on income tax returns as a medical expense.