Tray-based teeth whitening.

- What is it? | Is it the right method for you? | Should you buy a kit on your own or get one from your dentist? | How treatments are performed.

Tray whitening makes an excellent choice for those people who like to do things themselves. It's the original at-home method, and the one that's still considered to be the most effective and predictable of them all.

How do these systems work?

Tray-based systems (like those dispensed by dentists to their patients) work like this:

  • Plastic bleaching trays are made that fit over the user's upper and lower teeth.
  • To perform treatments, the user places whitening gel in the trays and then seats them over their teeth.
  • The trays are then worn for a prescribed period of time (often multiple hours per day, or else overnight), for a series of days or weeks, as the effects of the whitening process gradually take place.

(We outline the whole process in greater detail below.)

Custom tray-based whitening kit: Bleaching trays and whitening gel.

Tray whitening kit: Custom-made bleaching trays and whitener.

This is the method that started everything.

  • The technique of tray whitening was first described in dental literature in 1989.
  • During the 1990s, this method gained widespread acceptance by the dental community as a whole.
  • As its popularity grew with patients, manufacturers scrambled to respond to customer wants. The result is the whole range of at-home whitening products you see in stores today.

Due to its simplicity, safety, range of applications and comparatively low cost, more dentists use a tray-based approach with their patients than any other whitening method.


When does this method make the right choice?

Using a tray-based system can make an excellent choice. But there are issues that must be kept in mind.

You'll be on your own.

All your treatments will be performed by yourself, with no direct supervision or assistance from a dental professional. Because of this, you must be certain that:

  • The product you are using is safe and effective (see below for information about choosing an over-the-counter kit).
  • You know how to use it in an appropriate manner.
  • You are motivated enough to perform treatments and see the process through.


What other options do you have?

If the idea of performing at-home treatments doesn't appeal to you, you have the option of:
  • In-office / "laser" / professional whitening. - With this technique, treatments are performed in your dentist's office.

    ... as compared to a tray system: 1) It's a quicker process (although more than one appointment will probably be needed). 2) You usually end up paying more for the same results.

(We cover this topic in detail here: Comparing in-office vs. at-home bleaching: Which makes the best choice?

If the idea of wearing trays is the part you don't like, you can consider these alternatives:
  • Whitening strips. - No tray is needed. The whitener is embedded in plastic strips that you apply to your teeth.

    ... as compared to a tray system: 1) Strips have a reputation for being about as effective as tray technique. 2) Because they have a set length, they may not whiten all of your teeth that show.

  • Paint-on tooth whiteners. - With this method there are no trays or strips, you simply apply the product directly to your teeth.

    ... as compared to a tray system - 1) Typically considered much less effective. 2) This method does offer a convenient way to just lighten selected teeth.


Takeaways from this section.

There's plenty of literature (Heymann 2005, Dietschi 2006, Hasson 2008, Matis 2009) that suggests that tray-based technique can deliver results on par or better than the methods listed above.

If the idea of wearing a tray is acceptable to you, then there's no reason why this method shouldn't be your first choice or preferred method.


Where should you get your bleaching kit?

There's no shortage of whitening kits available to you as a consumer, either from your dentist, local store or else online.

a) From your dentist.

When you purchase a tray system from your dentist, the materials you use aren't necessarily better than what you can get from other sources on your own. But taking this approach does have some very distinct advantages. Having said that, not every person's case necessarily requires them.

When your dentist is involved, here's what you get.

1) Materials they'll stand behind.

  • The bleaching gel - You won't have any concerns about the quality and safety of the whitener you're using.

    You'll know its concentration is one that's been picked with you in mind. Both in terms of being able to produce results with your type of tooth staining and keeping side effects manageable.

  • Custom trays - Your bleaching trays will have been made especially for you.

    They'll stay in place well and have design features that help to maximize effectiveness and minimize your potential for side effects (see below).


2) Their expertise.

You'll also benefit from your dentist's wealth of knowledge, and experience gained from treating other patients.
Documenting a patient's pre-treatment shade.

Documenting a patient's pre-treatment shade.

a) Your dentist's pre-treatment examination will evaluate these issues:

  • They'll make sure the type of tooth staining you have is likely respond to the whitening process, and give you an idea of how long that is likely to take.
  • They'll document the pre-treatment shade of your teeth so they have a baseline for comparison as they monitor your progress throughout the bleaching process.
  • They'll look for existing dental work and make sure you know the time and cost that will be needed to replace it so your restorations match the new color of your teeth.


b) During your treatment process:
  • If side effects crop up, you'll have an expert available to help you get them under control.
  • They'll recognize your whitening endpoint, or know if extending your treatment period is likely to produce further results.


Takeaways from this section.

Having your dentist in charge of your whitening activities may be more expensive but you do get a lot of value. Doing so helps to remove a lot of uncertainty from the bleaching process.

b) Buying a kit on your own.

Other than buying from your dentist, there are plenty of OTC products available, either from your local store or online.

Be a smart consumer.

You might assume that all whitening products you see for sale have been approved by the U.S. Food and Drug Administration (FDA). This is not the case. They do not categorize them as drugs and therefore do not regulate them.

For this reason, buying a whitening kit on your own carries some risk. But by no means does that mean that good products don't exist. The fact that OTC products have been on the market for 20-plus years suggests that people who use them tend to be satisfied with their whitening experience and outcome.

When looking for a kit:
  • It only makes sense to go with an established brand name.
  • Some of the brands sold directly to dentists for use with their patients can also be found in stores and online. Our search came up with these: BriteSmile, Discus Dental, Lumibrite, Nite White, Opalescence, Pola, Ultradent and Zoom.


The main difference with OTC kits is the type of trays.

If you get a system on your own instead of through your dentist, there are likely bigger differences in the type of bleaching trays that you'll use as opposed to specifics about the whitener.

  • Store-bought kits utilize "stock" trays, not custom ones. A stock tray may be customizable to some extent but it's unlikely to have the same design features as one made by your dentist (see below).
  • You may find that some online sources offer dental laboratory services through which custom trays can be acquired.

We should point out that, while the use of custom trays does offer potential advantages (maximizing effectiveness, minimizing side effects), using them does not necessarily significantly impact a person's experience or outcome.

Takeaways from this section.

Especially if you're open to buying your whitener from one source and custom trays from another, it should be simple enough to obtain materials that duplicate those that your dentist has to offer.


When does doing it yourself make sense?

When choosing between an OTC source and your dentist, consider these points.
  • An OTC can make a good choice for people who have already performed tray whitening before. (People who already know what to do and what it should be like.)
  • It's best suited for cases that are routine or average. - See our "Is it effective" page.
  • A user's potential for side effects typically correlates with the strength of the whitener. So, when in doubt, less might be more, in the sense of avoiding problems.

    A 10% carbamide peroxide whitener is usually considered an entry-level product and a good choice for 1st-time users. (Using a higher concentration gel isn't better. See our Tips/Pointers page for more information.)


Talk to your dentist.

It's always best to discuss your whitening plans with your dentist before you initiate any type of whitening treatment. And even if you do anticipate that you'll just go ahead and get your kit on your own, you shouldn't feel sheepish about approaching them.

A part of your dentist's role is that of a dental counselor. It's their professional obligation to provide you with objective advice and opinion.

They may feel that an OTC system makes a poor choice and explain to you why. Or, they may instead have some OTC product recommendations for you. You'll never know unless you ask.

How does tray-based whitening work?

A) The bleaching trays.

1) Custom trays.

A dental impression used to make a custom bleaching tray.

A dental impression used to make a bleaching tray.

With a dentist-dispensed system, the type of bleaching trays that are worn are called "custom" trays. That's because they're fabricated specifically for the person who will wear them. Here's how they're made:
  • An upper and lower impression is taken of the patient's teeth and surrounding gum tissue.
  • A dental technician then uses the impressions to make plaster models of the patient's mouth.
  • The trays are then vacuum-molded directly on these models, thus ensuring a custom fit.


What do custom trays look like?

A custom-made bleaching tray.

The edges of a custom tray are trimmed so they end right at the gum line.

  • They're made out of a soft, flexible clear plastic.
  • One tray is made for the upper teeth and a separate one for the lowers.
  • They're trimmed so they fully cover over each tooth but come just short of the gum tissue.
  • They can be designed with "reservoirs." These are minute "extra" spaces on the front side of the teeth that hold just a little bit extra whitener.

    While it's debated if they actually help to improve the effectiveness of the whitening process, they have been shown to help to reduce the amount of gel that the user ends up swallowing.

Overall, the design of a custom tray helps to maximize the whitener's effectiveness and minimize the process' potential for creating side effects.

2) Stock trays.

Store-bought bleaching kits can't offer true custom trays. Instead, they come with what's referred to as "stock" trays.
  • In some cases, they're just pre-formed plastic shells that crudely fit over your teeth.
  • Some kits feature thermoplastic "boil and bite" trays. With these, you soften them up in hot water and then squish them over your teeth to personalize their fit. (See picture below.)
  • You don't necessarily have to buy a "kit." If you prefer, you can purchase your trays from one source and your whitening gel from another.


Disadvantages of stock trays.

As compared to their custom counterparts, stock bleaching trays (including those that are user modified) can't offer the same features and advantages.

A stock bleaching tray.

Stock bleaching trays have some disadvantages.

  • Their fit is often slack, which can make wearing them difficult.

    If you're performing your whitening sessions in public (like when doing errands) having snug-fitting trays can be important. But if you're just at home alone, this issue may not be much of a concern.

  • Because they're not custom trimmed, their edges are typically overextended and therefore may poke or rub your gums.

    Overextended trays also tend to hold whitener against your gum tissue, which can cause irritation. This usually isn't much of a concern with 10% carbamide peroxide gels but it can be with higher concentration products.

  • In some areas, a stock tray's edges might be short and not cover over each tooth fully. Minor discrepancies aren't usually a problem but trays that are substantially too short may result in uneven whitening.
  • Ill-fitting trays may not hold the whitener in close contact with your teeth, thus inhibiting its effectiveness.
  • Stock trays don't have reservoirs. Because of this, you'll tend to swallow more whitener, which may increase your risk for throat soreness.

These differences may not be all that important.

From a practical standpoint, it's easy enough to say that despite all of their shortcomings millions of people have bought over-the-counter kits and have successfully and uneventfully whitened their teeth using stock trays.

B) Treatments.

To perform a whitening session, you simply place bleaching gel in your trays and then slip them over your teeth.

What kind of gel is used?

The original type of whitener used with tray-based technique was 10% carbamide peroxide gel (it makes a good choice) but others can be used to. (We discuss whiteners in greater detail on our next page.)

Small dabs of whitener are placed in the tray.

Just put small dabs where it will touch the front side of your teeth.

Dispensing the gel.

Whitening gel is thick and gooey, so it will stay put in your trays. It usually comes in small bottles or syringes.
The idea is that you just place small dabs of it in those parts of the tray that touch the front side of your teeth. And only in those parts of the tray that cover over teeth that need treatment (your front teeth as opposed to molars).

Wipe away the excess.

After your trays have been seated, there will usually be some excess gel that escapes onto your gum tissue.

As a way of minimizing your potential for gum irritation, it's best to wipe away the excess gel with your finger or a toothbrush. (Be sure to rinse your hands or brush off immediately afterward so you don't get the gel on other things or body parts.)

How long do you wear your trays?

The answer to this lies in the instructions of the specific whitener you are using. It could be as short as 30 minutes. 2 hours or more is common. With some products, you have the option of wearing your trays overnight.

You should never wear your trays for longer than what's stated in your whitener's instructions.

C) Wrapping things up.

At the end of your session, you simply take your trays out. You'll want to brush any remaining gel off your teeth and rinse your mouth out. (Be careful, you may find your teeth are sensitive to cold water.)

Remove any remaining gel from your trays too, rinse them out and place them somewhere where they can air dry.

Tips and pointers.

If you're thinking about using this technique, you probably have more questions. Our next page provides specific details about wearing your trays and what to expect.


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