Teeth Whitening Pens (brush-on tooth whiteners).

- What are they? / How do you use them? / Advantages and Disadvantages / Effectiveness / Common side effects. / Safety concerns.


Link to How to use brush-on whiteners section.


Link to Whitening Pen Advantages section.

1) What are whitening "pens"?

Teeth whitening pens (brush-on tooth whiteners) are a type of over-the-counter at-home teeth bleaching product.

The technique itself utilizes the same types of peroxide compounds as other at-home systems. What makes it different is simply the method by which the bleaching agent is delivered to the surface of the teeth being treated.

The whitener delivery system, or really the lack of one, is what makes this technique unique.

For any type of tooth-whitening process to be effective, the bleaching agent must remain in contact with the surface of the teeth being treated. With some methods, this contact is facilitated by the use of bleaching trays or plastic strips.

In the case of brush-on products, no treatment device is involved. Instead:

  • The bleaching gel is painted directly onto the surface of the teeth using an applicator (brush or "pen").
  • Once it's been applied, it solidifies into an adherent film that produces the lightening effect.
  • After a period of time, the film ultimately dissolves or washes away.

As we outline below, the simplistic nature of this technique has a big impact on both its effectiveness and the applications it's best suited for.

2) How are whitening pens used? How long is the whitener left on your teeth?

It's easy enough to provide you with general answers to these questions. But specific details will vary with each individual product, so be sure to read your instructions for the best results.

Picture of a tooth-whitening pen.

A tooth-whitening pen (brush-style).

What's typical?

  • The whitener is painted onto the front side of the tooth or teeth you want to lighten.
  • It's left in place for a treatment period of about 20 to 30 minutes.
  • Some products allow twice-a-day applications.

Application details.

  • In general, you apply the whitener to all visible (front side) surfaces of each tooth, with emphasis on those areas that have the heaviest stains.
  • The extent of coverage should fall just short of reaching the gum line. (This helps to minimize gum irritation.)


Tips and pointers.

  • For better adherence, allow the film to dry for 10 to 15 seconds after application.
  • With some products, you may find that the whitener adheres to your teeth better if you dry them slightly (either 30 seconds of air drying or else wiping them off with a dry washcloth).
  • During treatment sessions, try to minimize activities that might dislodge the whitening film. Avoid rinsing, eating, and drinking. Also, try to minimize the amount of friction created by lip or cheek movements against your teeth.
  • Although these products tend to wear or wash off during a treatment session, it's still good practice to use a toothbrush and/or vigorously rinse afterward so to remove any film that remains.


3) Advantages of brush-on ("pen" applicator) whiteners.

This technique offers some unique features that other at-home systems can't easily match.

Applying whitener.

Picture of applying whitener to an individually darkened tooth.

An advantage of using a pen is that the whitener can be applied to individually darkened teeth.

a) It can be used to whiten individual teeth.

Some people may have a situation where they only need to lighten one, or just a few, teeth.
Different from other at-home methods, brush-on technique is easy to use in this fashion. It's a simple matter to limit the application of the bleaching gel to just selected teeth.
That's not to say that using this type of product will be especially effective (we have much more to say about that below). But with diligence, a person may be able to get satisfactory results, or at least make some degree of improvement, for the tooth that needs it.

[This page discusses treating individually darkened teeth in greater detail.]

b) It's a "trayless" technique.

For some people, the distinct advantage of using this method over other at-home systems is the simple fact that it doesn't require the use of any type of delivery appliance, such as a bleaching tray or plastic strip.

For example, having to use these items can be cumbersome, hard to keep in place, a cause of gum irritation, or trigger excessive salivation.

And for all of these reasons, just using a whitening pen may offer the opportunity for a person to perform treatments whereas otherwise they would not.

c) Pen and brush-on products are fairly inexpensive.

As compared to tray-based or whitening-strip systems, direct application products are usually the least expensive way to get introduced to at-home whitening.

While you may not be able to achieve the same level of results as with other methods (see below), the results you do get may motivate you to investigate and pursue other options.

4) Disadvantages of using teeth-whitening pens.

a) The film is easily dislodged.

A basic criticism of brush-on products is that they may wash away or get rubbed off fairly easily, possibly before they've been in place long enough to create much of a whitening effect.


Whitening teeth with peroxide compounds is a simple case of cause and effect. To achieve tooth lightening, the whitener must be in contact with the tooth's surface for an effective amount of time.

If it's not, the whitening results will either be minimal, uneven or take an extended number of treatments to achieve.

This method as compared to other at-home systems.

With other types of at-home products (strips, trays), the delivery apparatus that's involved:

  • Helps to maintain contact between the bleaching agent and the surface of the teeth being treated.
  • Acts as a barrier that helps to isolate the whitener from the general oral environment (helps to prevent it from being dislodged or become diluted by saliva).

As opposed to these methods, a system where the bleaching agent is just applied directly does not afford the same degree of protection for it. And this fact tends to inhibit its effectiveness (discussed below).

b) The whitener can be difficult to place properly.

Another criticism of having to use a pen or brush applicator when performing treatments is ease of use.

The actual act of applying the whitener, while seemingly easy, can instead be awkward. Ensuring full coverage over the entire surface of each tooth (including portions you can't see but others can) can be more of a challenge than you might expect.

One study (Date 2003) [page references] evaluated this issue.

  • A blue dye was added so the exact extent of the film could be measured.
  • Compared to the ideal, study participants were only able to apply the whitener over 85% of needed tooth surfaces.

5) Effectiveness of brush-on products.

(Note: This section compares the effectiveness of using pens to other whitening methods. If you're looking for general information about when the process of teeth whitening will work (any method), use this page: Types of tooth staining and their treatment solutions.)

A publication by Strassler (2006) reviewed the findings of studies that had evaluated the comparative effectiveness of paint-on tooth whiteners.

As listed below, it didn't have a lot of positive things to report for this technique.

a) Vs. whitening toothpaste.

A comparison of a brush-on product and a whitening toothpaste were found to produce the same (minimal) lightening effect.

  • It would be our assumption that most dentists would generally consider the use of whitening toothpaste to be the least effective at-home method (ask yours).
  • The brush-on product tested delivered the equivalent of 6% hp (hydrogen peroxide). To the defense of direct application technique, it's our impression that this concentration represents the lower end of the range found in most products today (see "Brands" below).
b) Vs. tray-based teeth whitening.

Brush-on whitener (6% hp) was found to be less effective than tray bleaching utilizing a 5% carbamide peroxide gel.

  • 10% is the standard entry-level concentration for tray technique. That implies that in comparison, using a tray-based system is typically substantially more effective.
Our conclusions about effectiveness.

There can be features of brush-on or whitening pen technique that may seem to make it a reasonable choice for you. And if so, it may be able to deliver a level of results that you find acceptable.

But in terms of creating dramatic results or treating stubborn types of staining, a tray-based system, whitening strips or treatments in your dentist's office make the more effective choice.

Takeaways from this section.

Just to recap, the way these types of products are applied pretty much explains why they have difficulty creating results on par with other types of systems. They have no protective device (tray or strip) that acts as a protective barrier that helps to keep the whitener from:

  1. Becoming diluted, or washed or scraped off the tooth's surface.
  2. Irritating all of the different soft tissues it ends up coming into contact with.

As solutions for these shortcomings:

  • Keeping the whitener on the user's teeth - A person might try to hold a big smile during sessions, so to keep their lips from dislodging the film. But grimacing for that long isn't easy.
  • Gum irritation - To reduce the level of side-effects created, these products are typically formulated with a relatively lower concentration of peroxide. But the less peroxide the tooth is exposed to, the less lightening effect that's created.

Due to these issues, this technique has difficulty creating the same level of effectiveness as competing methods.


6) Common side effects.

As mentioned above, most paint or pen products are founded on standard peroxide-based tooth bleaching. And that means that the types of side effects that one can expect are the same as typically experienced with other at-home methods.

The most common ones are gum irritation and tooth sensitivity. For most people, however, these are only mild in nature and do not require attention from a dental professional.

Collectively, our collection of reference sources (Barlow, 2003; Collins, 2004; Date, 2003; Gerlach, 2003; Li, 2004; Slezak, 2002) performed studies involving paint-on products that delivered a hydrogen peroxide content in the range of 6%.

  • Most of these studies did report that their subjects did experience side effects (for example, Date reported that 6% of participants experienced tooth sensitivity and 13% experienced oral tissue irritation).
  • However, none of these studies found that a subject needed to discontinue their whitening treatments because of adverse events related to side effects.

We discuss common side effects of peroxide-based whiteners and methods that can be used to manage them on this page.


7) What type of whitener is used?

Peroxide-based pen and brush-on products are typically formulated with one of the following compounds.

a) Carbamide peroxide.

Colgate's Simply White was the first brush-on product brought to the marketplace (2002). And as any dentist might guess, it was formulated with carbamide peroxide (at a concentration of 18%, which is equivalent to 6.3% hydrogen peroxide).

The reason this might be expected is because this compound has been utilized the most with tray-based systems (the technique that ultimately led to the explosion of over-the-counter at-home products you see in stores today).

No doubt Colgate was influenced by the abundance of research documenting its effectiveness and safety.

b) Hydrogen peroxide.

Other forms of peroxides have been utilized since then. Colgate Simply White Night (introduced in 2003) contained hydrogen peroxide. Crest Night Effects utilized sodium percarbonate peroxide.

What seems common nowadays.

It's our impression that current products tend to lean toward the use of hydrogen peroxide. Examples include:

Hydrogen peroxide brands.
  • Dazzling White® pen, Go Smile® pen, Smile Briter® pen, Venus White® pen

Confirming the exact formulation of a company's product isn't always possible. It's our impression that a hydrogen peroxide concentration between 6 and 9% is common.

Takeaways from this section.

We've become aware of a pen product that dispenses a high-concentration carbamide peroxide formula (over 40%) whose hydrogen peroxide equivalent would be on the order of around 15%.

The use of this type of high-concentration product would give us some concerns. Here's why:

  • 15% hp is the same level as some of the lower-concentration gels dentists use when whitening their patients' teeth during in-office sessions. And with that technique, great care is taken to prevent the whitener from coming into contact with soft oral tissues.
  • This is also the same as the highest concentration carbamide peroxide gel we've ever seen mentioned for use with a tray-based system. A technique with which there is at least some degree of isolation of the whitener from soft tissues.

Due to these concerns, it seems to us that to get better whitening results the best solution would be to change to a more effective technique (see above), not to choose a more concentrated pen product.


8) Are whitening pen and brush-on whiteners harmful to teeth or dental work?

Since most direct application products create their bleaching effect via the use of peroxide-based whiteners, we'll refer you to our safety information page that discusses this issue in detail.

As a point of reference:

  • The information on the above page discusses the use of 10% carbamide peroxide as a whitener. At this concentration, it's equivalent to 3.5% hydrogen peroxide.
  • It's our impression that most pen and brush-on products deliver a hydrogen peroxide concentration in the range of 6 to 9%.


a) Safety information specifically about paint-on whiteners.

We did find two studies that specifically evaluated the effect of brush-on products on teeth and dental restorations.

  • Slezak (2002) studied the effects of Colgate Simply White (which delivers a 6.3% hydrogen peroxide equivalent) on both enamel and tooth nerve tissue. It was determined that it created no harmful effects and was safe to use when applied as directed.
  • White (2003) evaluated the use of Crest Night Effects (which delivers a 5.3% hydrogen peroxide equivalent). Samples of tooth enamel, root dentin, and three types of dental filling materials were all exposed to simulated use of this product and no clinically significant effects were found.


b) A major issue about existing dental work.

Possibly the most important thing to know about peroxide whiteners and their effect on dental work is that while a person's teeth can be expected to lighten, the dental restorations on them generally will not.

This non-whitening effect means that after the bleaching process has been completed existing dental work will need to be replaced, so to match the new color of the person's teeth. Depending on the specifics of the situation, this might require a considerable amount of treatment time and expense.

For this reason, it's always a good idea to have your dentist check your situation out and advise you of any concerns before you initiate any type of whitening treatments.