Chapter 3: Teeth whitening results

Introduction

In the time and age of selfies and social media, a beautiful smile is often the place to start.

And here is something you and I can agree on:

the whiter your smile, the more natural and gleaming it will be… right?

Well … not really. A white smile may be bright, but it will not necessarily be natural.

In this article you will discover why, and many other things such as:

  • the types of results you can hope for with different teeth whitening procedures and products
  • how you can maintain them over time
  • the correct teeth whitening choices when you have dental restorations (crowns, veneers, implants, fillings, bridges …)
  • and more …

Happy reading!

What is a natural tooth shade?

Did you know that the natural color of teeth is off-white, similar to that of bone?

It is a step darker than pure white.

This contrasts with the popular, pure white, cosmetically enhanced smiles, presented in the media.

I know we are all influenced by the airbrushed celebrities and tooth whitening commercials, but reality is a little different.

Public opinion of what natural tooth color should be, is somewhat biased.

Stylised tooth shade chart
Stylised tooth shade chart

The explanation of why natural tooth color is darker than pure white is simple.

As you may already know, teeth consist of an outer enamel layer and an underlying dentin layer.

The latter is less transparent and darker than the former and shows through the enamel layer giving it light gray or (light) yellow color.

Let me reveal you some curious facts.

These are easy to understand based on what we said.

Why are larger teeth like molars or canines darker than other teeth?

Easy! This is due to a larger bulk of dentin showing through the enamel.

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

So, the obvious question is how white your teeth can get with the different teeth whitening methods available (?)

You are now ready for the next section.

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

Here are the facts.

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 four shades lighter.

    As previously said, your results will be quicker if you choose in-office whitening versus OTC products.

    And the reason is that higher concentrations of bleaching agents are used in the former.

    Let’s now briefly summarize the advantages of in-office teeth whitening.

    The benefits of in-office teeth whitening

    The avid readers of this guide already know some of this information, but it is still worth presenting the below synopsis for the benefit of all.

    • If performed by a professional, results are consistent. This is different from home whitening procedures with OTC products.
    • 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.
    • Results can be immediate. It only requires a short time (1-1:30 hours). So, it is ideal for busy patients.
    • Whitening results are long-lasting.

    But wait! Are teeth whitening results after an in-office procedure, set and done? Or may they vary during the following days?

    Just continue reading.

    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 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.

    I think I know what you are asking yourself. It is probably along the lines of “yes I understand, but what about the final result? What will it be like?”

    The next section is awaiting you.

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

    This will depend on the types of stains initially present.

    Now, different stains present different challenges.

    For instance, yellowish stains respond better to treatments than brownish stains.

    These are more challenging. Yes … unfortunately, not everything in the garden is rosy.

    But this notwithstanding, it is impossible to predict the exact final result of teeth whitening.

    Even if all your stains were yellow, it would be impossible.

    It is also impossible to tell (in advance) how many shades lighter your teeth will become.

    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.

    You may not know this … but 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.

    Now, 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 results will look more natural than with other less robust methods that cannot treat deep stains.

    We talked about yellow and brown stains, but what about gray stains?

    Can in-office teeth whitening treat grayish stains?

    Let’s address the elephant in the room first.

    Why do teeth have gray stains (at all)?

    The reason is that grayish undertone may be due to 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.

    Before we finish the stains-related questions … what about those white spots (on your teeth) that look like stains but are instead decalcifications?

    How effective is in-office teeth whitening if you have decalcifications?

    These will become more visible (and show as white spots) after the first procedure.

    Though, they will become less noticeable after a few treatments.

    Another question that may have been on your mind is ….

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

    A few believe it improves the quality of the bleaching process.

    Studies, though, say something different (see also https://www.suttonpda.com/in-office-teeth-whitening/#laser-light.

    No study has shown an advantage in whitening procedures using these lights.1 2

    One 2012 article 3 indicates that their usage:

    • “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;4 “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.5

    Hence, the ADA does not endorse these whitening procedures.6

    Let’s now answer an important question you may have.

    Can teeth be re-whitened?

    Yes, it is possible.

    Your dentist can re-whiten your teeth in the dental office.

    But 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.

    Let’s now look at results obtained with other teeth whitening strategies.

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

    Teeth whitening strips
    Teeth whitening strips

    Before we answer the question, a brief reminder … You can get these whitening products from a dentist or OTC.

    Now, on to the question.

    These products work proportionally to the concentrations of the bleaching agents (hydrogen peroxide or carbamide peroxide) present.7 8

    And based on all we previously said, it is probably not a surprise for you.

    The good news is that there is evidence they are better than no treatment at all or a placebo.9

    Though, most of the studies were short-term and financed or run by the manufacturers. Hence, the likelihood of bias remains high.10

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

    As a general rule, one can say can they lighten your teeth by 1 or 2 shades, after several days of use.11

    For instance, paint-on whitening gels can lighten your teeth by 1 or 2 shades.12

    Likewise, whitening washes usually take 3 months to lead to 1 or 2 shade improvement in tooth color.13

    The same is true for tray-based methods. You can observe a lightening effect of 1-2 shades within a few days.14 Though, you must follow manufacturers’ instructions.

    What about whitening toothpastes?

    They are not the open sesame to a glitterings smile. Their effect on the tooth color is also in the order of one or two shades.15

    Although, they are better than standard toothpastes because they can remove or prevent surface stains.16

    And, last but not least, is charcoal toothpaste good at the job of stains removal?

    Sorry to disappoint you but the evidence is not there.

    Despite being touted as effective whiteners, there is no data to back up these assertions.

    A 2017 review article in the Journal of the ADA concluded saying that:17

    • There is a lack of data to draw any conclusions about the safety and efficacy of this type of 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.

    As explained before (see Which are the best whitening strips?) for a product to qualify for the seal, the manufacturer must submit safety and efficacy data to the ADA.

    Let’s now investigate how you can continue enjoying a bright smile after your teeth whitening endeavors.

    Maintaining teeth whitening results

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

    Custom-fitted touch-up trays or take-home bleaching kits are the solution.

    Your dentist can provide them to you.

    He should also give you instructions for when and how to use them.

    If you follow them, you should be able to maintain the effectiveness of the results.

    Okay, I know what you are thinking.

    All this is interesting, but for how long should I use the trays at home? A few days, a few weeks or longer?

    A teeth whitening tray filled with gel for home use

    Although there is not an absolute rule, the general advice is to use them 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.

    So, can you conclude from the above that – as long as you continue using trays with gel – then prolonged results are forever?

    That is very unlikely.

    But the answer really depends on your lifestyle.

    Read on to find out.

    How long do in-office whitening results last for?

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

    Some good habits to maintain your teeth-whitening results

    As explained above, teeth-whitening results are not like diamonds, they are not forever.

    But you can still make yourself less susceptible to further staining.

    How?

    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.

    We are now going to change subject.

    Any thorough article about teeth whitening cannot omit discussing whitening results in the presence of dental restorations (crowns, veneers, implants …).

    So, let’s investigate this topic.

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

    Teeth whitening’s impact on the color of crowns, veneers, implants, bridges or fillings.

    Have you thought about the effect of teeth bleaching on preexisting dental work?

    If not, then you should.

    On the bright side …

    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 (unless you polish them).

    Why?

    Because they are very hard materials that can withstand the bleaching procedure.

    But the bad news are that … (read on).

    Teeth whitening’s impact on the structure of crowns, veneers, implants, bridges or fillings may not be negligeable.

    If you whiten your teeth in the presence of dental restorations, then you may have a problem.

    This is due to … Structural changes.

    Yes, bleaching agents may cause structural changes in your restorative materials.

    For example, surface changes, like the weakening of certain materials, can occur.

    These may also speed up their wearing down after frequent brushings.18 As a result, they may need to be replaced.

    Among materials that are significantly altered you will find:

    • Amalgams,
    • glass–ionomer cements,
    • and compomers,

    which are used to treat cavities.

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

    But that is not all!

    Prolonged treatment with bleaching agents also increases the release of mercury from amalgams.

    And if you are wondering why … It seems that this is due to microscopic changes in the amalgams’ surfaces. 19 20

    The effect of bleaching on these materials depends on the time of application and peroxide concentration.

    Negative effects increase proportionally with both factors: time of application and changes in the surfaces of amalgams.

    Thus, your dentist should complete this treatment in the shortest possible time.

    So, it makes sense that ….

    The ADA and the SCCP advise to use lower concentrations of bleaching agents.21

    You may also be interested to know that …

    Many laboratory studies have shown how teeth whitening may 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.22

    So, what general common-sense advice would you give someone, with dental restorations, about to bleach his teeth?

    That it is always better to check with one’s dentist before deciding.23

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

    Image of a dental crown
    Dental crown

    As we have seen above, restorations do not whiten during a bleaching procedure.

    Let’s see how this may affect your teeth whitening plan.

    First and foremost, it is always better to bleach your teeth before any restorations (veneers, crowns, implants, …).

    Why?

    Because it will help you to best match the color of the new restorations to that of your whitened teeth.

    This is especially true for your anterior (visible) teeth.

    And if you do not follow this common-sense approach …

    Your whitened teeth will look lighter than your restorations. Hence, you will have an uneven whitening.

    But what about if you already have restorations on your front facing teeth and you decide to undergo a teeth-whitening procedure?

    Is all hope lost?

    Nope, your dentist can do two things;

    • lighten your restorations by polishing them with a non-abrasive cleaning solution.
    • (The more involved solution) replace them if discoloration is important and polishing does not yield the desired result. The goal is to match the new whiter shade of your teeth.

    Additionally, if you have several restorations (and not just one), you should consider alternative solutions.

    These include veneers, crowns, bondings, instead of a whitening procedure.

    Dental veneer

    Let’s now move on (again) to a different subject.

    In the next section we will take a closer look at foods and drinks, especially at those that can take a toll on your smile.

    Food, drinks and teeth whitening results

    What should I avoid eating or drinking after teeth whitening? (Post-care recommendations)

    The question may be evocative of a long period of eating restrictions.

    But that is not true, be reassured.

    Restrictions apply only for 48 hours.

    Why?

    Because during this time it is easier for substances to penetrate 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 dental pellicle.

    So, what should one avoid consuming?

    The answer is quite simple: anything that could stain a white tee-shirt.

    It is the best way to 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 (see How do teeth get stained from colored food and tobacco?). 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.
    Teeth whitening mouthwash
    Teeth whitening mouthwash

    Now that we have seen the don’ts, let’s check the dos.

    What can I eat or drink after teeth whitening?

    Do you want to ensure that you will continue to say “cheese” without finding yourself tight-lipped?

    If so, here are the drinks you can consume 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.

    As for the foods, here are those you can consume 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).

    Consuming a staining substance shortly after teeth whitening

    If a staining substance has come into contact with your teeth within 48 hours (after the procedure), then …

    … you need to take immediate action!

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

    If you really you can’t do without a coffee (we empathize!) or a dark cola after teeth whitening, then use a straw.

    Why?

    Because it will limit contact to the back of your teeth.

    Final remarks

    Congratulations!

    If you have read this chapter, you are one step closer to “teeth whitening wisdom”.

    But after learning about:

    • natural tooth color,
    • results obtained with different teeth whitening strategies,
    • how to maintain teeth whitening result,
    • foods and drinks that do, or do not, impact your smile,
    • how to plan teeth whitening in the presence of dental restorations (crowns, veneers, implants, fillings, and bridges),
    • etc…

    you may be curious to learn even more.

    And that is great!

    So, if that is the case, go on to read the remaining chapters:

    And, if you have not checked them already, don’t forget the previous chapters of this guide:

    See you soon!

    Bibliography

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