Ultimate Guide on Teeth Whitening

Image of a camel's stained yellow and brown teeth
Camel’s teeth that could do with some teeth whitening

Getting your teeth whitened can make a huge difference in your life. And if you want to improve your smile, you are not alone. The American Association of Orthodontists did a survey in 2013. They found that nearly 90% of the interviewed doctors (sample of 1200) had had such a request from some of their patients.

Many people spend a significant amount of money on cosmetics and expensive clothes. But the overall appearance is not enhanced unless a person has a beautiful smile.

Have your teeth gotten yellower? Are you ready to remove stains that have gradually built up on your teeth over the years? Get the facts first!

The below guide features 104 questions covering all aspects of teeth whitening. Enjoy!

Quick navigation

  1. Teeth whitening methods
  2. Dental stains and indications for teeth whitening
  3. Dental cleaning: preparing for in-office teeth whitening
  4. In-office dental bleaching
  5. Hydrogen peroxide and carbamide peroxide
  6. Zoom® and Opalescence® Boost
  7. Custom made and over-the-counter teeth whitening trays
  8. How to treat resistant teeth stains
  9. Teeth whitening results
  10. Maintaining teeth whitening results
  11. Eating and drinking restrictions after teeth whitening
  12. Home teeth whitening: whitening strips, toothpaste, paint-on films, trays with gels
  13. Teeth whitening: sensitivity and gums’ irritation
  14. Seeing a dentist before teeth whitening. Safety, risks, and contraindications of teeth whitening.
  15. Teeth whitening and crowns, veneers, implants, fillings, and bridges
  16. Costs of teeth whitening
  17. Foods that preserve your teeth
  18. DIY, natural teeth whitening methods
  19. References

Teeth whitening methods

What is teeth whitening?

It is one of the least invasive procedures in cosmetic dentistry. It aims to reduce or remove surface stains from your teeth.

Teeth whitening may be done to restore the original tooth shade or to whiten beyond the original tooth color.

It has become one of the most popular dental esthetics procedures according to the ADA1

Millions of people suffer from discoloration of their dentition to varying degrees.

Read on to discover which methods they could use to address their problem.

How can you whiten your teeth?

There are three broad types of methods, which are commonly used to whiten one’s teeth:

  • At a dental office under your dentist’s supervision.
    • He will use a range of high-tech clinical equipment to achieve the desired results.
    • This will take place without any harm to either your tooth enamel or dentin.
    • Your dentist will use higher concentrations of bleaching agents. These penetrate your enamel (and even dentin) deeper than the other two methods (see below).
    • This approach provides immediate results.
    • Conditions are controlled ensuring a safe and pain-free experience.
    • It is the safest form of bleaching since measures are taken to protect your gums from the bleaching agents. These (measures) consist of using a protective gel or a rubber shield.
    • Over-the-counter products do not offer this possibility.
  • At home with products prescribed and dispensed by your dentist.
    • Typically, you will be using a custom-made tray that will fit your teeth.
    • You will use gels with lower concentrations of bleaching agents than those used in the office.
    • There are also other do-it-at-home bleaching systems. These use disposable trays that are malleable to fit your dentition. The trays are pre-loaded with proper amounts of whitening gels.
  • On your own, by purchasing your own over-the-counter (OTC) whitening products:
    • These include many possibilities, suiting different budgets and temperaments.
    • They use low concentrations of whitening agents.
    • Results are not immediately visible.
    • Some of the most common are:
      Application of a teeth whitening strip by a young woman
      Young woman applying a teeth whitening strip
      • Whitening strips where the gel is embedded. You will apply the plastic strip is on your teeth;
      • trays with gel, where a mouthguard holds the gel in place;
      • bleaching pens;
      • toothpaste with hydrogen peroxide;
      • paint-on gels or varnishes, …

In-office procedures instead use higher concentrations and provide quicker results.

It is also possible to use products that do not contain whitening agents. These include toothpaste with abrasives (e.g., charcoal particles).

Make sure you read the next question before taking a decision…

Which is the best teeth-whitening system for me?

There is no wrong or right method if your dentist supervises it. If your teeth are sensitive and you want quick results, then you are a better candidate for in-office treatment.

An in-home treatment system is better suited if you are on a budget. You may also want to whiten your teeth in the comfort of your own home.

Your dentist will provide you the best advice after a thorough dental examination. The optimal solution will depend on your dental health, budget, temperament, and lifestyle.

Dental stains and indications for teeth whitening

What types of discolorations affect teeth?

Discoloration can be extrinsic or intrinsic. The former is limited to the tooth surface and involves the dental pellicle. This is a protein film covering your teeth. This film forms almost immediately after teeth brushing, or after chewing.

Some causes of extrinsic discoloration include:

Image of yellow calculus and plaque on teeth
Yellow calculus and plaque on teeth
  • Ingestion of certain colored foods and drinks.
  • Use of tobacco.
  • Use of topical medications like an antiseptic mouthwash. These may combine with tannins (naturally occurring substances) found in tea, wine, …, and stain teeth.
  • Plaque and calculus (which is neglected plaque having calcified). Calculus can be mainly found around the gumline.

Intrinsic discoloration instead involves the internal structure of the tooth (or of all the teeth). Some causes include :

  • Use of antibiotics for the treatment of acne, like tetracycline.
  • Tooth decay (dental caries).
  • Dental trauma.
  • Fluorosis which results from excessive ingestion of fluoride during enamel formation.

Check the next question to learn more about teeth staining.

How do teeth turn yellow or even dark?

Your teeth may change from white to a less bright, dull color as a result of many causes:

  • Natural aging, because of brushing.
    • The hard, glossy, white outer shell of your teeth, called the enamel, will wear out and get thinner over time.
    • The softer, yellowish underlying substance, called dentin, will show through. Also, enamel naturally darkens over time.
Internal tooth anatomy
Internal tooth anatomy
  • Plaque builds up and causes your teeth to look yellow.
    • Plaque is a sticky film infested with bacteria.
    • It hardens and forms tartar, which contains minerals and also affects tooth color.
  • Consumption of drinks and foods containing pigments.
    • These coloring agents impact your teeth over time by attaching to your enamel.
    • Enamel is porous, and tiny organic particles can penetrate the pores and remain attached. This is why your teeth turn purple when you eat blueberries. A higher porosity will lead to more persistent stains.
    • Acidic substances increase your enamel’s porosity by demineralizing its crystals. So any substance whose fermentation produces acids will affect the porosity. Fermentation results from bacteria present in the mouth, which decompose carbohydrates.
    • Some foods and beverages containing pigments include:
      • dark sodas
      • coffee
      • wine
      • fruit juices
      • colored foods such as tomatoes, sweets, blueberries, blackberries
      • and tea.
Teeth with braces
Teeth with braces
  • Orthodontic treatments:
    • tend to discolor or stain teeth over time.
    • The metal brackets and wires used in these procedures trap bacteria and food.
    • This is also true, albeit to a lesser degree, if you choose Invisalign® instead of traditional braces.
  • Trauma such as if you receive a blow or suffer from a fall.
    • These events may stain or discolor your teeth.
    • The darkening results from the production of dentin. Now, dentin is the darker, naturally yellow, bony tissue underneath enamel. The latter is instead the glossy outer surface.
    • If the event happened during your childhood, the change in structure could show later, in adulthood.
    • Whitening is not as effective in such situations because discoloration comes from inside the teeth.
  • Sometimes teeth look yellow because the outer hard enamel has never grown. Your enamel’s lack of growth could be due to trauma suffered during childhood. The darker, naturally yellow dentin is thus exposed.
  • Exposure to tetracycline and doxycycline (antibiotics) may interfere with your teeth formation.
    • This phenomenon happens either as a baby, or when in the womb.
    • Teeth discoloration can then show later during your adulthood. It will reflect the darkening or yellowing of dentin in the inner layers of your teeth.
    • For these types of cases, whitening treatments tend to be less effective.
Image a smoker's stained teeth
Smoker’s smile
  • Tobacco use can lead to stubborn stains. These (stains) can consist of smoking cigarettes, pipes, cigars or even chewing it. Two chemical compounds are involved:
    • nicotine which is colorless but gives teeth a yellowish stain in the presence of oxygen
    • tar which instead is naturally dark.
  • Excessive absorption of fluoride compounds during enamel formation.
    • It may lead to staining or darkening of teeth (fluorosis).
    • Fluoride has benefits in helping to prevent cavity formation. Hence, it is often present in drinking water. Yet, an excess of fluoride intake may result from:
      • abundant consumption of fluoridated tap water;
      • ingestion of fluoride toothpaste;
      • mouth rinses (which children tend to ingest).

But can you avoid or reduce teeth staining? Move on to the next question.

How do you prevent teeth staining?

Staining may come from the consumption of certain drinks and foods. You can avoid it or reduce it by:

  • Decreasing (or avoiding) their consumption.
  • Rinsing and brushing your teeth after consumption (of such foods or drinks).
  • Using a straw to avoid direct contact with staining drinks, such as wine, coffee, or tea.

And if you can’t prevent teeth staining, you may be wondering which is the most effective way to remove it.

Which stains does in-office dental whitening remove?

Good candidates for in-office teeth whitening are those with stains that have accumulated from:

  • dark soda,
  • sauces,
  • fruits, in particular berries,
  • coffee,
  • red wine,
  • fruit juices,
  • colored foods,
  • tea,
  • antibiotic tetracycline stains.

Can my plaque and tartar be removed at home?

Your plaque and tartar are challenging to remove. They need professional help, either by a dentist or by a dental hygienist.

Dental cleaning: preparing for in-office teeth whitening

What do I need to do before in-office teeth whitening?

Before teeth bleaching at a dental office you:

  • Should brush your teeth before teeth whitening.
  • Consider using lip balm before the appointment to avoid dry or sore lips.
  • Should also get your teeth cleaned beforehand.

Do I need to get my teeth cleaned before in-office teeth whitening?

Removing plaque and calculus via a professional dental cleaning is necessary. You should do this before teeth whitening.

Calculus, also called tartar, consists in calcium deposits. It is a chalky substance that accumulates over time.

Plaque, instead, is a sticky film infested with bacteria.

Healthy tooth and gums compared to tooth with plaque and gum inflammation
Dental plaque and gum inflammation

A whitening gel cannot penetrate through calculus and plaque. Their presence will lead to blotchy results.

Also, when a hygienist polishes your teeth, she will remove some of your surface stains. Hence, the whitening gel will better penetrate within your enamel.

Finally, dental cleaning may show some cavities or leaking dental fillings. You will need to address these before teeth whitening.

But could dental cleaning be enough to restore your teeth’s original color?

Is dental cleaning enough to whiten my teeth?

Dental plaque and tartar may cover part of your teeth. They will get stained if you:

  • smoke,
  • drink coffee, tea, or red wine,
  • on a regular basis.

Simple dental cleaning and polishing may be enough to remove your superficial stains.

It may happen though, that staining penetrates the enamel and even dentin. If that is the case, dental cleaning will not be satisfactory.

Stages gum disease : gingivitis, periodontal disease with creation of a deepening pocket.
How calculus can lead to gingivitis and finally periodontal disease

In-office dental bleaching

How do in-office teeth whitening procedures remove dental stains?

In-office teeth whitening procedures make use of gels containing a bleaching agent. This agent is either carbamide peroxide or hydrogen peroxide.

These compounds penetrate the enamel. Stains get exfoliated or broken up and eliminated. They bring your teeth back to their natural color. It is the oxygen molecules within the whitening agents that break up these stains.

How does in-office teeth whitening take place?

Dentist performing teeth whitening treatment with a patient
Dentist performing teeth whitening treatment

There are some variations amongst different procedures. We describe the main steps below.

These follow a pretty standard routine. A trained dentist will:

  • Take a shade measurement of your teeth before the procedure begins.
    • Shade measurement aims to compare your existing tooth color to a shade with a stylized chart
    • This measurement provides a benchmark to gauge improvement after teeth whitening.
    • Once this has been determined, the whitening process will take place.
  • Polish your teeth using pumice.
  • Place a cheek retractor to expose all the teeth that are visible when you smile.
  • Cover your eyes, gums, and lips, to protect them from the bleaching gel.
    • A hardening resin or a liquid rubber dam is used and painted over the gums.
    • The tips of the gums between the teeth will also be protected from the bleaching agents.
    • Finally, only your teeth will be exposed. This process may take up to 10 minutes.
  • Apply a special whitening gel to your teeth.
    • The gel releases an active ingredient (hydrogen peroxide or carbamide peroxide), once in the mouth.
    • Teeth bleaching will take place in three to four 15-20 minute sessions.
  • Remove the previous layer during each session.
In-office teeth whitening. Gums protected from contact with whitening gel. Cheek retractors used
Patient with cheek retractors during in-office teeth whitening. Gums are protected.
  • Make you rinse your mouth with a lot of water, and polish your teeth with pumice again (if necessary).
  • Assess the degree of teeth whitening to gauge whether the procedure should be repeated or not.
  • Apply more whitening gel if necessary
  • Remove your cheek retractors so that you be able to rinse your mouth.
  • Take your final teeth shade. Temporary dehydration of your teeth may enhance the immediate postoperative result.

According to American Dental Association:

  • “heat and light application may initially increase whitening due to greater dehydration”;
  • “this reverses with time”;
  • the final color will be visible 2-6 weeks after the procedure.2

For some whitening procedures, your dentist will expose and activate the gel during each session. He will use a special high-intensity UV light for this.

Depending on the results, or on your desired outcome, another session may be necessary. Your dentist may also suggest continuing the treatment with home whitening trays.

How many in-office visits are necessary for teeth whitening?

The average is one visit, but depending on the individual case, this could vary. Obviously, a combination of in-office visits and home treatment with custom-made trays is also possible. Tray delivery will help complete the whitening process.

Which light source is used during accelerated or LED in-office teeth whitening?

The most frequent sources of light used are LED, plasma arc, and halogen. The type of light most suited to activate hydrogen peroxide is in the blue spectrum. This is because these wavelengths are best suited to activate the bleaching agent (hydrogen peroxide).

Is laser light, used for in-office teeth whitening, effective?

There is not a lot of data about the efficacy of laser bleaching. Also, the data is difficult to compare because of the differences:

  • In protocols used,
  • concentrations of hydrogen peroxide,
  • wavelengths of lasers3

However, some comparative studies with high concentrations of hydrogen peroxide showed improved whitening. Although:

  • “Most often comparable results were found irrespective of light exposure.”4
  • “There is no evidence that light activation (power bleaching with high-intensity light) with high concentrated hydrogen peroxide bleaching gels results in more effective bleaching with a longer lasting effect.” 5

Is in-office teeth whitening painful or uncomfortable?

It is neither painful nor uncomfortable. Most patients usually listen to music, watch a DVD or doze off, during the entire procedure.

Patient undergoing in-office teeth whitening. The gel is activated by light irradiation
Light activation of teeth whitening gel during an in-office teeth whitening procedure

What are the advantages and disadvantages of in-office teeth whitening?

Unlike home bleaching techniques, results are fast and visible after a one- hour session. Home whitening techniques are slower and are intended to be used over a period of 2-4 weeks 6. However, you may benefit from staying in the comfort of your own home.

Hydrogen peroxide and carbamide peroxide

How are carbamide peroxide and hydrogen peroxide used in dentistry?

You will find them as active ingredients in tooth whitening products used in dental offices. Their concentrations will be high, in the order of 25–35% of hydrogen peroxide. But these products will be used for shorter time periods.7

Otherwise, when lower concentrations are used, you will find them:

  • In oral hygiene products. These include toothpaste and mouth rinses. Their disinfecting action will help prevent plaque formation and inflammation of your gums.8
  • Mass market products, or over-the-counter teeth whitening products.

What is the difference between carbamide peroxide and hydrogen peroxide?

Some whitening products contain carbamide peroxide, while others use hydrogen peroxide instead. Both are bleaching agents.

“Carbamide peroxide decomposes to release hydrogen peroxide in an aqueous medium (10% carbamide peroxide yields roughly 3.5% hydrogen peroxide).”9

According to a study in the Journal of the American Dental Association 10:

  • both produced important results;
  • were equally effective at removing deep stains (intrinsic) as well as surface (extrinsic) stains;
  • provided concentrations were equal.

Does hydrogen peroxide cause more sensitivity than carbamide peroxide?

A study11 published in the Journal of the ADA12 did not show any significant differences in teeth sensitivity.

Does hydrogen peroxide work faster than carbamide peroxide?

Hydrogen peroxide’s bleaching effect will occur within 30-60 minutes.

Carbamide instead will break down your stains more slowly. It releases 50% of its whitening effect within 2 hours of its application. Its activity may continue for up to 6 hours afterward.

What is the difference between bleaching agents and non-bleaching agents?

Non-bleaching agents remove only surface stains. Bleaching agents instead, remove deep stains (intrinsic) as well as surface (extrinsic) stains. They also contain carbamide peroxide or hydrogen peroxide.

Zoom® and Opalescence® Boost

Which in-office teeth whitening procedures are most common?

Two of the most popular in-office dental bleaching procedures are:

  • Zoom®
  • Opalescence® Boost

What is Opalescence® Boost?

It is a teeth whitening procedure that:

  • lasts about an hour, depending on the degree of tooth discoloration.
  • Does not need light to activate the gel.
  • Whitens your teeth with a sticky and viscous gel, which stays in place on your teeth.
  • Can remove common stains brought about by your lifestyle (eating, drinking smoking,..).
  • Can also treat other difficult stains like those resulting from:
    • trauma;
    • prescription medications (tetracycline).

What are the post whitening care instructions after Opalescence® Boost?

If you experience post-whitening sensitivity, your dentist should give you a potassium nitrate gel. You can use it in a customized tray until the condition subsides.

How can I enjoy prolonged whitening results after Opalescence® Boost?

Your dentist should provide you with a take-home maintenance system. You may use it periodically to help maintain your teeth whiter for longer.

He should also give you instructions on when and how to use it.

What is Zoom® teeth whitening?

Patient with a light source device irradiating teeth whitening gel, during in-office procedure
Patient with a light source device irradiating teeth whitening gel, during an in-office procedure

Zoom® is a very popular teeth whitening procedure that:

  • generally lasts about 1 hour and is done at the office.
  • Consists of three 15 minutes applications of a whitening gel. These contain hydrogen peroxide (25%). They lighten both enamel and dentin stains.
  • Makes use of an ultraviolet lamp to speed up the whitening process.

What are the post-treatment care instructions after Zoom® teeth whitening?

A fluoride paste-gel is applied to your teeth to manage sensitivity. This is done right after the procedure.

A small percentage of patients (about 7-8 %) experience sensitivity.

It subsides significantly after 24 hours, and should completely disappear within 48 hours.

How can I enjoy prolonged results after Zoom® teeth whitening?

Your dentist can provide you with custom-fitted touch-up trays or take-home bleaching kits. He should also give you instructions for when and how to use them. If you follow them, you be should be able to you maintain the effectiveness of the results.

For how long should I use the trays at home, after the in-office whitening procedure?

Filling of a tray with teeth whitening gel, for home use
A teeth whitening tray filled with gel for home use

Your dentist should tailor home treatments, with custom-made trays, to your specific situation.

Usually, patients use them for teeth whitening for:

  • about 1 hour a day for a period of 7 to 10 days;
  • then 1-2 days every 6-12 months to maintain a lighter shade.

Each patient is undoubtedly unique. While some may not need them at all, others may need longer treatment periods.

Custom made and over-the-counter teeth whitening trays

What are the advantages of custom-made teeth bleaching trays?

They are custom made so that they perfectly fit your teeth and bite. They are fabricated for home use under your dentist’s supervision.

Dental whitening trays and gel for home use
Dental whitening trays and gel for home use

Your dentist will give you with custom-fitted trays. You will be able to fill this type of trays with a whitening gel without any risk of (the gel) leaking out.

You will thus enjoy optimal results, and avoid irritation of your gums.

You can use custom-fitted trays after the in-office dental procedure. You can also use them as a stand-alone home teeth-whitening procedure.

What are the disadvantages and side effects of custom-made teeth whitening trays?

Its higher cost when compared to over-the-counter trays. It is the only disadvantage of a dentist-prescribed tray for your home-use.

Dental laboratory for the manufacture of custom-made dental appliances
Dental laboratory for the manufacture of custom-made dental appliances

Your dentist will take impressions of your teeth. After that, he will send custom trays to a laboratory to be tailor-made.

These trays avoid leakage of the bleaching agent. Your gums will thus not get irritated.

As for their side effect, albeit less common, is that you may experience jaw pain or a sore throat. These happen because of excessively long tray usage. Though, it may also be true when it comes to using over-the-counter trays.


What are the risks of using over-the-counter teeth whitening trays?

Gel used to whiten your teeth may leak from a tray that does not fit properly to your mouth and bite.

The leakage causes your gums to become irritated. It may also decrease the whitening effect.

The American Academy of Cosmetic Dentistry recommends using patient custom-fitted mouth trays. It also advises that they are made under your dentist’s supervision.

How to treat resistant teeth stains

Which stains are difficult to treat? How do you treat them?

Heavy tobacco stains may require as much as three months of in-office treatment.13

Also, tetracycline-stained teeth take long to respond. Satisfactory results are obtained after 2-6 months of nightly treatment. But the degree of teeth whitening stills differs from normal teeth.14

How to treat grayish or heavy stains that do not respond to in-office teeth whitening?

Your dentist can use other approaches to mask stains, when teeth whitening fails. These include:

  • bonding, where a thin coat of adhesive polymer resin is applied to your discolored tooth. The coating is then irradiated with a light and bonds to your tooth.
  • Veneers to mask a discolored tooth more effectively than bonding.

Teeth whitening results

What is a natural tooth shade?

The natural color of teeth is off-white, similar to that of bone. This is in contrast to the popular, pure white, cosmetically enhanced smiles, presented in the media. Hence, public opinion of what natural color teeth should have is biased.

Stylised tooth shade chart compared to a patient's upper frontal teeth
Stylised tooth shade chart

Teeth consist of an outer enamel layer and an underlying dentin layer. The latter is less transparent and darker than the former. As a result, larger teeth like molars or canines will look darker. This is due to a larger bulk of dentin showing through the enamel.

Likewise, females’ teeth are somewhat whiter than males’. This is because they are smaller and hence have less dentin.

How white will my teeth get after in-office teeth whitening?

After the 30-60 minutes treatment, your teeth whitening may vary:

  • from 10 to 15 shades whiter,
  • to 2 to 5 shades lighter.

However, 10-15 shades lighter in color is only seen in a small percentage of patients.

Most patients have an average result of 7-8 shades lighter when using Zoom® Whitening. The average whitening potency of Opalescence® Boost is approximately 4 shades lighter.

Your results will be quicker if you choose in-office whitening versus over-the-counter products. The reason is that higher concentrations of bleaching agents are used in the former.

How will my teeth color change shortly after teeth whitening?

Your teeth color may lose some of its light shade the week following the procedure.

Sometimes, part of the color change after teeth whitening is due to dehydration. This regresses with time.

As your teeth rehydrate, the color rebounds back to a shade darker than the one observed immediately after treatment.

What will my final result be like after in-office teeth whitening?

Yellowish stains respond better to treatments than brownish stains. Though, it is impossible to predict the final result of teeth whitening.

It is also impossible to tell how many shades lighter your teeth will become, in advance. The actual outcome depends on:

  • your initial level of staining.
  • On the mineral composition of your teeth

The only way to know for certain is by trying an in-office teeth whitening procedure.

Your dentist will always take an initial and final measure of your teeth’s shade. He will use these for comparison purposes.

Tooth shade guide with a patient
Tooth shade guide

The final natural shade is different for each patient. Some patients want their teeth to look natural, as they were before their staining. Although not a guarantee, this is possible.

In-office procedures bring out your natural color by removing deep as well as surface stains. Hence the final results will look more natural.

Can in-office teeth whitening treat grayish stains?

Some teeth have a grayish undertone because of certain medications taken at a young age. These include:

  • tetracycline, to treat a disease;
  • minocycline in adolescence or young adulthood to treat acne.

Tetracycline and minocycline staining involve the dentin layer which is underneath the enamel. Prolonged bleaching may thus be required because the gel takes longer to reach this inner layer.

This type of discoloration does not respond well to tooth whitening. Though it should improve after treatment, it may persist, at least partially.

Does the use of high-intensity light improve in-office teeth whitening?

A few believe it improves the quality of the bleaching process. Though, some studies have shown no advantage in whitening procedures using these lights.15 16

One 2012 article17 indicates that the usage of this type of light:

  • “increases the risk of tooth sensitivity during in-office bleaching”;
  • “may not improve the bleaching effect for high concentrations of hydrogen peroxide (25–35%)”.

So, the article encourages dentists to avoid or to be cautious when using this type of light-activation.

Finally, some more recent articles report that the use of in-office high-intensity light:

  • did not increase efficacy nor speed-up in-office bleaching;18 “The in-office bleaching treatment of vital teeth did not show improvement with the use of light activator sources for the purpose of accelerating the process of the bleaching gel and achieving better results.”
  • tended to increase the temperature of dental pulp.19

Hence, the American Dental Association does not endorse these whitening procedures.20

How can teeth be re-whitened?

Your dentist can re-whiten your teeth in the dental office. You can also do it at home if you have custom-made bleaching trays and whitening gels. You will be able to whiten your teeth as often as you need to.

Talk to your dentist to find out how often you should repeat your whitening procedure. You can then determine which whitening products would work best for you. Base your decision on your individual needs and lifestyle.

What are the benefits of the results obtained with in-office teeth whitening?

  • Results can be immediate. It only requires a short time (1-1:30 hours). So, it is ideal for busy patients.
  • If performed by a professional, results are consistent. This is different from home whitening procedures with over the counter products.
  • Whitening results are long-lasting.
  • It is one of the safest dental treatments available (since it is supervised by a dentist).
  • Sensitivity levels generally remain low, both during and after the procedure.

Do whitening strips, gels on trays and paint-on films for home use, whiten teeth effectively?

Teeth whitening strips
Teeth whitening strips

You can get these whitening products from a dentist or over-the-counter.

They work proportionally to the concentrations of the bleaching agents (hydrogen peroxide or carbamide peroxide)21. There is evidence they are better than no treatment at all or a placebo.

Most of the studies were short-term, and financed or run by the manufacturers. Hence, the likelihood of bias remains high.

There is a general lack of data to assess their long-term effects, on diverse populations.

Are teeth-whitening strips effective?

They can lighten your teeth by 1 or 2 shades, after several days of use.22

How good are results obtained with paint-on whitening gels?

You can lighten your teeth by 1 or 2 shades.23

Is whitening toothpaste effective?

Its whitening effect on the tooth color is in the order of one or two shades.24 Comparisons with standard toothpaste have shown you can remove or prevent surface stains.25

Is charcoal toothpaste effective at teeth whitening?

There is no evidence that using toothpaste with charcoal will whiten your teeth.

A 2017 review article26 in the Journal of the American Dental Association concluded saying that:

  • There is lack of data to draw any conclusions about safety and efficacy of this toothpaste.
  • Dentists “should advise their patients to be cautious when using charcoal and charcoal-based dentifrices with unproven claims of efficacy and safety.”

To ensure you choose a safe and effective dental product, select those that have the ADA seal of acceptance. For a product to qualify for the Seal, the manufacturer must submit safety and efficacy data to the ADA.

How good are results obtained with whitening washes?

Whitening washes usually take 3 months to lead to 1 or 2 shade improvement in tooth color.27

How good are results obtained with tray-based teeth whitening?

A lightening effect of 1-2 shades can be observed within a few days.28 But you must follow manufacturers’ instructions.

How good are the results obtained with in-office teeth whitening if you have calcifications?

If you have decalcifications, then these will show as white spots afterward. They may become more visible after a first whitening procedure. But they will become less noticeable after a few treatments.

Maintaining teeth whitening results

How long do in-office whitening results last? Is teeth whitening a permanent solution?

Teeth whitening is not a permanent solution. You need to repeat it periodically, to maintain the whiteness of your teeth.

Stains will come back gradually over time. This also depends on your lifestyle. For example,

  • if you are a smoker;
  • if you consume large amounts of staining foods or drinks such as coffee, red wine, tea, etc…

You may see the whiteness begin to fade in as little time as 4 to 6 weeks.

If you avoid or dramatically reduce these sources of staining, you may not need another whitening treatment for at least 6 to 12 months.

How can I maintain my teeth-whitening results?

Teeth-whitening does not make you less susceptible to further staining. The best way to maintain your teeth’s natural color is through:

  • following proper dental hygiene regimens such as:
    • brushing your teeth two to three times a day
    • flossing once a day to remove plaque
    • brushing immediately after meals
    • rinsing your mouth with water after meals
    • using daily antibacterial mouthwashes to kill plaque bacteria.
  • Avoiding consumption of beverages that easily stain teeth such as:
    • dark colas
    • red wine
    • coffee
  • Using a straw to avoid direct contact between these drinks and your front facing teeth.
  • Brushing or rinsing quickly after consumption of these foods and beverages.
  • Using a whitening toothpaste occasionally (4-6 times a month) to prevent staining.
  • Doing touch-up treatments by wearing custom-fitted trays or disposable trays.
    • A few hours for a couple of weeks should be enough.
    • Their frequency will depend on the method used, and on your lifestyle. The need for touch-up treatments may vary from once every six months to once every 1-2 years.

Eating and drinking restrictions after teeth whitening

What can you eat after teeth whitening? (Post-care recommendations)

Eating restrictions apply for 48 hours. During this time it is easier for substances to penetrate into the enamel. Teeth are dehydrated and enamel’s microscopic pores are open during the first 24 to 48 hours.

This phenomenon is due to the removal of the acquired pellicle. It is a protective layer everyone has, and that contains the staining. It forms again over 24 to 48 hours.

Avoid consuming anything that could stain a white tee-shirt. This will preserve the optimal results of the whitening procedure. More specifically, you should avoid the following:

  • Dark staining drinks such as:
    • coffee
    • tea
    • colored alcoholic beverages
    • colored fruit juices
    • colored colas
    • red wine, etc.
  • Potato chips
  • All tobacco products. Smoking a cigarette during the first 24 hours will leave a stain on your teeth. You can make moderate use of electronic cigarettes.
  • You should avoid all fruits especially berries, but you can eat bananas.
  • Colored lipstick
  • All dark staining sauces including:
    • Soy sauce
    • Bolognese sauce
    • red sauces
    • ketchup
    • mustard, etc.
  • Red meat
  • Chocolate
  • Lettuce and tomatoes

During the first 48 hours after teeth whitening you should also avoid:

  • red or blue toothpaste.
  • Colored gels.
  • Colored mouthwashes or fluoride treatments.
  • Periodontal treatments.
  • Chlorhexidine, if you are using it to prevent dental plaque, for instance.
Teeth whitening mouthwash
Teeth whitening mouthwash

I have eaten, drunk or consumed a staining substance after teeth whitening, what should I do?

Rinse with water and brush your teeth as soon as possible.

Can I drink coffee or dark colas after teeth whitening?

Try to avoid it during the first 48 hours. If you really cannot, use a straw to limit contact to the back of your teeth.

What can I drink after teeth whitening?

You can consume the following drinks during the first 48 hours after teeth whitening:

  • milk
  • water (still / sparkling)
  • white wine
  • clear alcohol (Vodka/Gin)
  • white lemonade
  • clear soda (sprite, 7up)
  • club Soda or tonic water
  • coconut water but not coconut milk

What can I eat after teeth whitening?

You can consume the following foods within the first 48 hours after teeth whitening:

  • meats:
    • chicken breast without the skin or turkey (minus the fat)
    • canned chicken breast.
  • Fish: white fish, white tuna (without vinegar), fish and chips.
  • Carbohydrates:
    • white rice
    • peeled potatoes (mashed, baked or fried)
    • plain pasta with white sauces (Alfredo sauce for instance)
    • flour tortillas (white)
    • white bread (no crust)
    • crackers
    • oatmeal
    • cream of wheat
    • cereals (e.g., Rice Krispies)
    • pancakes with white syrup.
  • Fruits and vegetables: bananas, cauliflower, apples, white onion, pears (no peels).
  • Sauces: white gravy, sour cream, mayonnaise.
  • Egg whites.
  • Desserts: vanilla puddings
  • Dairy products:
    • White plain or vanilla low-fat yogurt
    • white cheese (mozzarella, white cheddar, cottage cheese).

Home teeth whitening: whitening strips, toothpaste, paint-on films, trays with gels

Which home teeth whitening products usually provide a bleaching action?

The following products contain a bleaching agent:

  • Gels with trays which can be used over-the-counter or supplied by your dentist;
  • paint-on films ;
  • whitening strips.

How do you whiten your teeth with paint-on films teeth whitening?

You should apply the peroxide-based bleaching gel on the teeth’ surface with a small brush. It then hardens and forms a coat covering the teeth and adhering to enamel. This film provides the whitening effect. After some time the film dissolves and washes away.

Manufacturers advise twice daily application, during 14 days.29

As for any teeth-whitening procedure, it is preferable to consult a dental professional before making a decision.

How do you whiten your teeth with gels on trays?

Teeth whitening trays fitting onto frontal upper teeth
Teeth whitening trays fitting onto teeth

Whitening trays can be over-the-counter or custom-made under your dentist’s supervision.

They are filled with bleaching gel and used between 2-4 hours over a few days. Or, you can wear a tray during your sleep, 6-7 hours per night, during 10 nights. The length of treatment also depends on the extent of staining and desired lightening effect.

The former approach makes use of higher concentration of bleaching agents. As a result, you should handle the gels with care.

Your dentist is the one who should ideally choose the concentration, best suited to your needs.

How do you use teeth-whitening strips?

These are thin, flexible plastic strips with a layer of (peroxide) whitening gel. They were created in the late eighties to avoid the use of trays and gel.

They are shaped to fit the surfaces of teeth. Kits are sold with two different sets of strips:

  • one will fit the anterior (buccal facing) lower teeth surfaces;
  • the other, the anterior upper (buccal facing) teeth.

You should use a strip by gently pressing it across the teeth. The gel layer should make good contact with the teeth’s surface. Hydrogen peroxide in low concentrations (5 to 14%) is present in the gel30 It is released during the bonding with the teeth’s surface.

Many types of whitening strips with different instructions currently exist. Typically, you should wear your strip for 30 minutes a day, twice a day, during 14 days. Other newer types instead, only need one 30-minute application per day, with the same whitening result as the other products31.

How does whitening toothpaste work?

Whitening toothpaste removes difficult surface stains. It does not affect intrinsic stains and its action:

Toothbrush in a little dog's mouth
Toothbrush in a little dog’s mouth
  • May rely on enzymes, although these are not always present. They break down organic molecules in the biofilm (on teeth);32
  • Depends on large quantities of abrasive compounds. These eliminate surface stains from teeth surfaces. They include alumina, dicalcium phosphate dihydrate, and silica;33
  • Depends on the presence of detergents;
  • May rely on small quantities of bleaching agents like hydrogen peroxide or carbamide peroxide. But these are usually not present.34 35

The quantities of abrasive compounds need to be calibrated to avoid the thinning of the enamel. This process would, in turn, lead to darkening of the tooth as the naturally yellow dentin becomes more visible (through the enamel).

Which are the best whitening strips?

The only whitening strips to have received the ADA36 seal of acceptance are the Crest 3D White Whitestrips (Glamorous White). They are also the only over-the-counter whitening product to have received this seal.

You should be aware that preparing all the safety and efficacy data for submission to the ADA involves a lot of work. Many manufacturers simply decide to avoid. It does not mean their products could not meet the ADA standards.

How do you use whitening toothpaste?

When you brush your teeth, you should keep the slurry that forms over your teeth for 5 minutes.

How to use whitening mouthwashes or rinses

Whitening washes or rinses contain bleaching agents like hydrogen peroxide, which react with stains. Manufacturers advise rinsing for 60 seconds, twice a day. You only have to swish the product around in your mouth.37

Teeth whitening: sensitivity and gums’ irritation

What are the most common side effects of teeth whitening?

The typical side effects are:

  • More tooth sensitivity to cold, hot, or sweet;
  • irritation of your gums because of the oxidizing effect of bleaching agents. Hence, your gums need to be protected.

These symptoms tend to disappear once the bleaching stops. 38

Are gums’ irritation and tooth sensitivity reversible after teeth whitening?

Yes, no study has ever shown an irreversible effect.

How frequent is sensitivity after teeth whitening with over-the-counter products (OTC)?

A study showed39 that for chemically based over-the-counter tooth-whitening products (gel in trays, paint-on films, and whitening strips):

  • two-thirds of patients experienced a transient mild to moderate sensitivity;
  • ” ‘mild’ to ‘moderate’ tooth sensitivity and gingival irritation were the most common side effects”;
  • patients experienced sensitivity during the first period after the teeth-whitening procedure;
  • “the whitening strips and products with high concentrations of hydrogen peroxide caused more users to complain about tooth sensitivity.”

Why do I experience sensitivity after teeth whitening?

Your teeth sensitivity results from the penetration hydrogen peroxide. First, it will penetrate your enamel, then your dentin, all the way to the pulp during a 5-15-minute exposure period.

How long does tooth sensitivity last for, after teeth whitening, and when does it occur?

Tooth sensitivity can last several days and usually starts at the time of treatment.40

How long does gum sensitivity last after teeth whitening, and when does it occur?

Gum irritation begins within a day of the treatment, and can also last several days.41

What affects tooth sensitivity after teeth whitening?

According to the American Dental Association, sensitivity42:

  • “is generally related to:
    • the peroxide concentration of the material
    • the contact time.”
  • “may depend on:
    • the quality of the bleaching material,
    • the techniques used,
    • an individual’s response to the bleaching treatment methods and materials.”

How can I treat tooth sensitivity after teeth whitening?

Use a type of toothpaste that can provide relief for sensitive teeth. You may use Sensodyne or other similar products by Colgate or Crest. They contain potassium nitrate and sodium nitrate.

You will reduce tooth sensitivity. These products soothe the dental nerve endings. You can use them both before, during, and after the procedure.

Also, consider chewing sugarless gum to reduce the peroxide levels.

If you have a headache, take what you usually use for headaches, such as Ibuprofen.

Seeing a dentist before teeth whitening. Safety, risks, and contraindications of teeth whitening.

Do I need to see a dentist before teeth whitening?

There are many causes of discoloration. Your dentist will need to determine why your teeth are no longer as white as before. He will also assess whether this is due to tooth decay or not.

If you have cavities (tooth decay), teeth whitening will be contraindicated. You will need to treat your cavities before attempting any procedure. Otherwise, bleaching agents will penetrate the inner areas of the tooth. This will likely cause significant sensitivity.

It is important that your dentist gauges if teeth-whitening is the right treatment for your staining.

He will also discuss the whitening products or procedures that are best suited for you. It could be part of your routine 6-month regular visit to your dentist. This is something we highly recommend.

What are the risks of bleaching discolored teeth without a prior dental examination?

The ADA43 advises patients to discuss with their dentists what whitening procedure is best for them. You should do this before commencing such treatments.

During a dental examination your dentist will:

Images showing gradual process of tooth cavity formation
Gradual process of tooth cavity formation
  • Check for tooth abnormalities such as caries or leaking dental restorations (fillings).
    • Some changes in tooth color could be the only visible sign of such problems. They cause teeth to appear darker.
    • Teeth whitening will mask the underlying tooth decay.
    • This process (tooth decay) may continue to worsen if left untreated. And, it will likely lead to the need for more expensive and extensive treatments.44
  • Verify the presence of cracks and gum disease (periodontitis).
    • If present, your dentist will delay the whitening procedure until correction of these problems
    • This approach will avoid irritations or other unpleasant outcomes.
Images of a normal tooth and a tooth with gum disease (periodontitis)
Normal tooth and tooth with gum disease (periodontitis)
  • Identify your dental restorations, such as existing crowns, veneers or fillings.
    • Their shade is not affected by conventional whitening agents. Your dentist will discuss with you whether teeth bleaching will have a desirable outcome.
    • You should expect extra costs and/or minor risks from replacing your dental restorations after teeth whitening. Replacement may be necessary to get a uniform post-procedure tooth color.
  • Identify a devitalized tooth. If it is discolored, it will need a very different whitening procedure than a live tooth. Though it is a low-risk routine treatment.45

You should obviously share the following information with your dentist before any treatment:

  • Any past issues about tooth sensitivity.
  • A history of allergies to specific compounds used in the bleaching gels.

It will enable him to adapt your teeth whitening procedure to your specific needs.

This approach is necessary to avoid potential issues or any discomfort.

Your dentist may use x-rays to gauge and determine your oral dental health. X-rays help identify:

  • Cavities,
  • oral infections,
  • gum disease,

even at their early stage.

Is in-office teeth whitening safe? What are its consequences?

It is not harmful, and the most important potential side effects are:
An increased sensitivity to cold during the first 1-3 days after treatment. Otherwise, its side effects are no different than those observed during regular food ingestion.

An irritation of the gums. This happens if they are not properly protected during the in-office whitening procedure.

Is teeth-whitening for everybody? What are its contraindications?

We strongly suggest that you have a consultation before any teeth whitening procedure. This is because it may not be the best treatment for you, if:

  • Your dental restorations are defective. Your dentist will inform you that your teeth are decayed.
    • When this is the case, they must first be treated.
    • Tooth decay is a process where plaque (a sticky film of bacteria) brings about the destruction of the tooth’s enamel.
Image showing stages of caries formation : enamel caries, dentin caries, pulpitis and periodontitis
Stages of caries formation : enamel caries, dentin caries, pulpitis and periodontitis
  • You have decalcifications (which show as white spots).
  • You are suffering from the loss of a tooth’s surface, exposing the dentin. This issue may be due to:
    • tooth decay (see the previous point),
    • trauma,
    • excessive consumption of citrus fruits or carbonated soft drinks,
    • teeth grinding,
    • aggressive brushing,
    • defects in enamel development.
Tooth anatomy : root, neck and crown of a tooth
Tooth anatomy: root, neck and crown of a tooth
  • Your expectations are unrealistic.
  • You have gum disease (gingivitis or periodontitis).
  • You have developed gum recession. This (gum recession) happens when the gum line pulls back or wears away exposing the root of the tooth. The root is the part covered by your gums, in healthy teeth.
  • The root is yellow, and does not bleach like the rest of the tooth, also called the crown. In fact, roots do not have an enamel layer, and whitening procedures will not work.

Safety during: a) in-office teeth whitening and b) use of OTC products. How are gums protected?

Your dentist will use a protective gel or a rubber sheath. These will cover your gums during in-office teeth whitening. They drastically reduce any risk of gums’ irritation due to contact with the bleaching agents.

These protective measures are not available during treatments with over-the-counter products.

Are over-the-counter (OTC) products safe? Is home teeth whitening safe under dental supervision?

There are no safety issues if:

  • You use “at-home tooth bleaching materials containing 10% carbamide peroxide (3.5% hydrogen peroxide)”,
  • under supervision by dental professionals.46 47  48

Since data accumulated over 20 years did not show any long-term negative impact on patients’ health. The data also included some long-term studies.

Unfortunately, there is limited clinical evidence about the safety and effectiveness of OTC products.49 50

Patients are generally not aware of how to report negative events (adverse events) through FDA’s MedWatch system. Hence, these are probably almost never reported.

Overuse of OTC products may damage the glossy outer surface of your teeth (enamel). Two cases of patients with significant enamel damage have been reported. These events may have been due to the overuse or the low pH (acidity) of OTC whitening products.51

Negative changes in your enamel may be related to the low pH of the products and/or their overuse.52

Peroxide-based products can irritate, or corrode your gums. As a result, you may feel a burning sensation. These effects will increase with the chemicals’ concentration, time, amount of product, etc.53 54 55 56 57

Thus, if you consider using OTC products, you should have a dental examination. Seeing your dentist will help you choose the best method for your specific situation. It will limit the risk of harm and improve the quality of the whitening effect.

What concentrations of tooth whitening agents are safe?

According to the European Union’s SCCP :58 59 60

  • Only dental professionals can provide tooth whitening products with 0.1 – 6% hydrogen peroxide. These products include compounds releasing hydrogen peroxide like carbamide peroxide.
  • The first cycle of usage of such products is by a dental professional or under his direct supervision. This approach would reduce risk (for example) that a patient may inadvertently swallow bleaching gel because of inappropriate use of whitening trays.
  • The patient must be at least 18 years old.
  • Higher concentrations of these molecules are unsafe.

Tooth whitening (or oral hygiene) products for home use in the European Union cannot contain more than 0.1% of hydrogen peroxide (or equivalent amounts of carbamide peroxide).

In the USA much higher concentrations (3–6% hydrogen peroxide) 61 are instead present in over-the-counter products for home use. These include teeth whitening strips, paint-on products …

Are whitening products safe because the FDA regulates them?

The FDA does not regulate any teeth whitening products 62 irrespective of the usage or type. So the FDA will not provide any oversight for:

  • Teeth whitening products used in a dental office,
  • “dentist-dispensed products for at-home use”,
  • over-the-counter (patient-purchased) products,
  • “products used in non-dental settings”.

Tooth whitening products fall under the U.S. cosmetic regulations. These are less strict than those for medical products.

So, do not be deceived by the fact that some of these products are easily accessible (such as OTC products). This may lead you to think they are innocuous. Whereas their inappropriate use may result in:

  • Irritation of your gums,
  • undesirable effects for your teeth.

These effects may also be due to their low pH and poor product quality.

You should note, though, that the FDA regulates dental lasers used for in-office teeth whitening.63

How can you ensure a whitening product is safe? What is the American Dental Association (ADA) Seal of Acceptance?

One way to choose whether your whitening product is safe is to see whether it carries the ADA seal of acceptance.

It will mean that the manufacturer :

  • Has supplied data about its safety and efficacy
  • members of the ADA’s Council on Scientific Affairs have reviewed the submissions and believe it adheres to their standards

But the list of over-the-counter products carrying this seal is limited to one type of products. These are the Crest 3D White Whitestrips (Glamorous White). The ADA, in fact, believes that oversight by your dentist is necessary for safe and effective use of whitening products.

Is teeth whitening safe during pregnancy or lactation?

There seem to be no specific side effects for pregnant women. Though, it is preferable that you don’t undergo this procedure because of the lack of safety data.

Teeth whitening is also not recommended if you are lactating.

Can children and teenagers do in-office teeth whitening?

There is general lack of data to establish appropriate use and indications in these populations.

If you have a child who may benefit from teeth whitening, he or she should at least have all his or her permanent teeth.

Bleaching is usually not advised in children under 16. This is because they have an enlarged pulp chamber or nerve within their tooth. As a result, the sensitivity of the pulp could be significant.

It is preferable for teens to wait until they are 18 years old. However, some teens may benefit from the procedure before this age.

Before taking the decision, you should first get their dentist’s approval. Also, the young patient needs to be responsible.

Consider using a tailored made teeth whitening tray to avoid leakage of the gel.

As advised by the ADA64, “close professional and parental/guardian supervision are needed to maximize benefits and minimize adverse effects and overuse.”65

Am I too old for tooth whitening?

Teeth whitening can provide benefits to all adults irrespective of age. It may not be appropriate for you if you have:
crowns, implants or bridges on the front facing teeth,

if you have experienced increased gum sensitivity over the years.

We always recommend that you seek professional advice before considering this treatment.

Can teeth-whitening increase the risk of oral cancer?

No. The risk of oral cancer does not increase with the use of bleaching agents of any type. Studies have demonstrated this. 66 67 68

There is insufficient evidence to classify hydrogen peroxide as cancerogenic.

The International Agency of Research on Cancer (IARC) has evaluated hydrogen peroxide. As a result, it considers it unclassifiable regarding carcinogenicity to humans. The chemical belongs to Group 3: Unclassifiable. 69

According to the SCCNFP70:

  • The use of 3.6% hydrogen peroxide products (10% carbamide peroxide) in the oral cavity, does not represent a cancer risk.
  • This is the case when the users “do not have an increased risk of oral cancer due to tobacco use, alcohol abuse, or genetic predisposition.”
  • Repeated use of tooth whitening products might increase the risk of oral cancer.

What should I do if my gums are sore or white after a bleaching procedure?

If you see that your gums are white or sore after any bleaching procedure, please follow up with your dentist.

Teeth whitening and crowns, veneers, implants, fillings, and bridges

Does teeth whitening change the color of crowns, veneers, implants, bridges or fillings?

Teeth whitening has a very limited impact on the color of materials used in fabricating crowns, bridges, and implants.

Four units dental bridge
Four units dental bridge

Ceramics or composite materials (composite resins) as well as gold alloy, do not change color. They are very hard materials that can withstand the bleaching procedure. Some polishing, after bleaching, would be enough for these materials.

But, other materials are significantly altered. They may need to be replaced after bleaching. These include:

  • Amalgam
  • glass–ionomer cement
  • and compomer

which are used to treat cavities.

For instance, the solubility of glass-ionomers and other types of cement has been reported to increase.

Prolonged treatment with bleaching agents also increases the release of mercury from amalgams. It seems that this is due to microscopic changes in the amalgams’ surfaces. 71 72

The effect of bleaching on these materials depends on the time of application and peroxide concentration. Negative effects increase proportionally with both factors. Thus, your dentist should complete this treatment in the shortest possible time.

As suggested by the ADA73 and the SCCP74, lower concentrations of bleaching agents are advisable.75

How can teeth whitening affect crowns, veneers, implants, bridges or fillings (restorations)?

Bleaching agents may cause structural changes in your restorative materials. As a result, they may need to be replaced. Surface changes, like the weakening of certain materials, can occur. These may also speed up their wearing down after frequent brushings.76

Many laboratory studies have shown that teeth whitening may also affect the bond strength between:

  • The materials (crowns, implants, fillings, ..)
  • and your enamel or dentin.

For instance, it affects the bond strength between enamel and resin-based fillings.77 Thus, it is always better to check with your dentist before deciding, if a teeth-whitening treatment is right for you.78

Dental veneer
Dental veneer

How can my dentist lighten veneers, implants, bridges, fillings or crowns?

Your dentist can lighten your veneers, implants, bridges or crowns (restorations).

He will polish them with a non-abrasive cleaning solution.

If discoloration is important, though, it may be necessary to have a new restoration.

Teeth whitening before or after veneers, bridges, crowns, implants or fillings?

Image of a dental crown
Dental crown

Restorations do not whiten. If you plan to whiten your teeth, it is always better to do this before any restorations (veneers, crowns, implants, ..) are made. This is especially true for your anterior (visible) teeth. It will help you to best match the color of the new restorations to that of your whitened teeth.

If you do not proceed as described, your whitened teeth will look lighter than your restorations. You will have an uneven whitening.

You may already have restorations on your front facing teeth. If you decide to whiten your teeth, you may need to replace those restorations to match the new whiter shade of your teeth.

Additionally, if you have several restorations, you should consider alternative solutions. These include veneers, crowns, bondings, instead of a whitening procedure.

Costs of teeth whitening

How much does teeth whitening cost in the USA?

Prices in the market can vary significantly:

  • In-office procedures cost up to $1000 but usually range between $300-$800.
  • Whitening trays provided by a dental professional, range anywhere between $300-$600.
  • For over the counter products prices vary widely starting:
    • As low as $3-$8 for a toothpaste;
    • $10-$40 for an over the counter tray at the local pharmacy;
    • between $40-$70 for whitening strips.

Do insurances cover teeth whitening?

Most insurances do not cover teeth whitening procedures. This is also true of most other cosmetic dentistry treatments.

But, many patients use their Flex-spending programs. These are offered by their employers to pay for these procedures. It benefits them from the tax deduction provided through these programs.

Foods that preserve your teeth

Which foods protect your pearly whites?

Fortunately, not all foods will stain your teeth. Several foods can help you maintain their natural color, and may even whiten them:

  • Apples, celery, pears, almonds, and carrots.Since they are high in fibers, when you chew them they will have the same effect as a natural toothbrush. The fibers will act as “micro toothbrushes”, scrubbing the surface of your teeth.They also stimulate the production of saliva which neutralizes acids produced by bacterial food fermentation.
  • Cacao, cauliflowers, rhubarb, broccoli, spinach, carrots.They are rich in oxalic acid, hence the odd feeling in your mouth, after consuming them. Oxalic acid forms calcium oxalate, which in turn creates a protective layer covering the tooth.You should avoid these foods if you suffer from gout or renal insufficiency.

DIY, natural teeth whitening methods

What is the best and safest DIY method of whitening your teeth?

Proper, routine oral hygiene, with regular brushing and flossing of your teeth, are tried-and-true methods. They will avoid food and bacteria hardening into plaque, which will then stain your teeth.

Ideally, you should brush and floss your teeth after every meal or snack. Avoid frequent snacking, if you cannot brush your teeth, and floss them regularly.

Can I whiten my teeth just by rinsing my mouth with hydrogen peroxide?

No, this would not whiten your teeth. It may also cause serious damage to your soft tissues including gums, and even your teeth.

Can I use baking soda mixed with lemon juice, water, hydrogen peroxide, oranges or apple cider to whiten my teeth?

Baking soda is the common name of a compound called sodium bicarbonate. It is a little alkaline, white and crystalline in structure.

Baking soda mixtures will damage your enamel since baking soda is very abrasive.

As for natural acids contained in apple cider or fruits, they may erode your teeth, weakening your enamel. This is especially true of lemon juice since it is very acidic. It will make your teeth more prone to decay and sensitivity.

Image of a lemon and of backing soda
Lemon and baking soda

The cumulative effect of the acids and baking soda may lead to permanent loss of your enamel (the outer hard glossy layer of your teeth).

Even though your teeth may look whiter and shinier in the short term, in time, they may darken. This is due to the underlying dentin becoming more visible through a thinner enamel layer.

You could also get dark spots if you decide to brush your teeth with baking soda while wearing braces or permanent retainers.

Remember also that a thinner layer of enamel makes your teeth more prone to cavities.

Also, baking soda cannot kill bacterias and help you prevent cavities. You will have to brush your teeth with toothpaste, after using baking soda.

Can I use baking soda mixed with strawberries to whiten my teeth?

In a recent study79, the efficacy of baking soda mixed with strawberry (DIY method) was compared to standard whitening procedures. These included:

  • Over-the-counter methods, following manufacturers’ instructions;
  • dentist-dispensed whitening products for home use;
  • dental, in-office whitening.

The lowest lightening effect was obtained with the baking soda strawberry mixture (DIY) method.

Will fruits with digestive enzymes, like pineapple and mango, improve teeth whitening?

There is no scientific proof about the effects of natural enzymes on teeth whitening. But eating fruits regularly is a very healthy choice for sure!

Is charcoal powder useful for teeth whitening?

There is no evidence that scrubbing your teeth with charcoal powder will lighten them.

A 2017 review article80 in the Journal of the American Dental Association showed that:

  • There is limited data to make claims about its efficacy and safety;
  • some results seem to show a negative effect. Because of its abrasive nature, the enamel layer wears out. It becomes thinner, and dentin (which is more yellow) shows through.

Can oil pulling or swishing your mouth with natural oils help you whiten your teeth?

The American dental association does not recommend oil pulling. Thus it cannot replace dental therapy.81

Despite the limited evidence, some studies show that you can improve your oral hygiene by swishing oil.82

Image of coconut oil and a coconut
Coconut oil

By “pulling out bacteria” this procedure may help you reduce:

  • Plaque formation,
  • inflammation of the gums.

However, you need to use it regularly and correctly.83

It has been shown that oil swishing may reduce the presence of the two groups of bacteria. These are mainly responsible for initiating caries (Streptococcus mutans and Lactobacillus species)84

They start caries and cause inflammation of the gums (periodontitis). This results in pain, potential tooth loss, and infections. They do this by producing lactic acid in the presence of fermentable carbohydrates.

Several studies show a preventive efficacy of oil-pulling in:

  • Reducing plaque formation,
  • and plaque-induced inflammation of the gums.

Moreover, in some studies, the effect of oil swishing was not inferior to that of a chlorhexidine-containing mouthwash.85 86

Chlorhexidine is an antiseptic compound. It is considered the “gold standard” to treat oral infections. It can help prevent tooth decay. Unfortunately, it has a bad taste, and stains teeth brown.

Olive oil’s constituents have “antimicrobial, immunomodulatory, and antioxidative effect.”87

Sesame oil instead, “contains:

  • Sesamin,
  • sesamolin,
  • sesaminol

and has detoxification, antioxidant, and antibiotic actions.”88 For instance, sesame oil was shown to have antibacterial properties against S. mutans.89

Sunflower oil was shown to have antibacterial activity against C. albicans. It is a yeast that plays a role in the formation of children’s plaque and caries.90

Finally, the beneficial properties of coconut oil may be due to the presence of lauric acid (a fatty acid). Approximately 45-53% of coconut oil is made of this fatty acid.91 Now, lauric acid:

  • Has antimicrobial characteristics against gram-positive bacteria and several fungi and viruses. For instance, coconut oil was active against both S. mutans and C. albicans.92
  • “Can react with alkalis present in saliva, to form sodium laureate-soap like substance, which reduces plaque adhesion and accumulation, and possesses cleansing action.”93

You may thus want to consider a more natural, safer approach to protect your teeth and gums. Edible oils may replace artificial, chemically produced antiseptics while maintaining oral hygiene, without any side effects.

How do you do oil pulling? What is the procedure?

According to published literature94, you may use the following steps to carry out oil pulling:

  1. Take a tablespoon full of oil. You can use a teaspoon if your child undertakes the procedure.
  2. Swish the oil around your mouth for about 20 minutes. Ideally, you should do this before breakfast and with an empty stomach.
  3. If your jaw aches, consider reducing the time to 5-10 minutes.
  4. You should adopt a sitting position with chin up.
  5. Ensure that when you swish it, the oil is forced through your teeth.
  6. If done correctly, the oil should become milky white.
  7. Spitting it out in a paper towel or trashcan to avoid clogging the pipes.
  8. Do not swallow the oil as it contains bacteria and toxins.
  9. You should then consider rinsing your mouth with water, and proceed with routine tooth brushing.

Oil pulling is not recommended, if you have children under 5 years of age, because of the risk of inspiration.


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