Professional whitening treatments: Side Effects

- Do in-office sessions hurt? / Will you have pain or sensitivity afterward? / Remedies for side effects.

Gum tissue

Link to Gum Irritation section.

Tooth sensitivity

Link to Tooth Sensitivity section.

In-office teeth whitening, just like any other peroxide-based bleaching method, can create side effects. The most common ones are tooth and gum sensitivity or irritation. They can occur either during or after your bleaching session.

A) Side effects during treatment.

a) Tooth sensitivity.

It's possible that you may feel a few isolated zaps or tingles during your whitening procedure. Based on the frequency or severity of what you notice, your dentist might decide that it's best to cut your bleaching session short.

Being able to communicate with your dentist is the key here.

Set up a prearranged hand signal (or possibly your dentist will have a small bell you can signal with) so you can indicate to them that you're experiencing sensations that need to be evaluated.

Picture of paint-on dental dam in place for bleaching treatments.

The blue (paint-on) dental dam protects the gums from irritation.

b) Gum-tissue irritation.

The peroxide bleaching agents found in in-office whiteners are caustic in nature and can irritate or even damage soft oral tissues (gums, lips, cheeks, tongue).
This is why a dentist isolates their patient's teeth by way of placing a dental dam before the whitener is applied. An important safety feature of in-office technique is being able to limit the peroxide whitener to tooth contact only.

Why dentists don't "numb up" whitening patients.

If the potential for experiencing pain during treatment exists, you might wonder why a dentist doesn't just go ahead and numb up their patient's mouth before the bleaching process is begun. The reason they don't is because by not using anesthetic, they make the whitening procedure safer.

  • If a patient's teeth become sensitive during their treatment process, it may be a warning sign that their session should be cut short before the nerve tissue inside them becomes seriously aggravated.
  • Equally important, any pain that appears can be a warning sign that the dental dam is leaking and therefore allowing the peroxide to irritate or burn the patient's gums, lips or cheeks.


If the patient's mouth had been numbed, these signals would not be available.

B) Side effects after treatment.

a) Thermal sensitivity.

After your whitening session, you may experience increased tooth sensitivity to hot and cold stimuli such as foods and beverages.

In most cases, this type of sensitivity is self-limiting and will dissipate on its own within a matter of days. However, you should always feel free to contact your dentist and report what you have noticed so they can advise you accordingly.

Professional remedies.

One remedy for thermal sensitivity is the application of fluoride to the surface of the affected teeth. And in fact, it's common that fluoride application is included as the last step of the in-office bleaching process.

Picture of a tube of toothpaste 'for sensitive teeth.'

Desensitizing toothpaste can aid in managing bleaching sensitivity..

Home remedies.

A solution for post-bleaching hot and cold tooth sensitivity that you can do yourself involves the use of desensitizing toothpaste. You should be able to find this type of product at any store that has a "dental" section.

Most brands are labeled "for sensitive teeth" and contain the active ingredient potassium nitrate or else fluoride. Continued use of the product, over a period of some days and weeks, should be able to eliminate, or at least significantly reduce, the amount of sensitivity you have.

b) Tooth pain and discomfort.

You may find that you've experienced little if any tooth discomfort during your whitening session but then, some hours afterward, your teeth begin to hurt. This pain may range from just slight to moderate in intensity. It can come in sudden sharp episodes or else as a continuous dull ache.

This type of discomfort is usually a result of inflammation of the tooth's nerve due to one of the following sources of irritation:


As with any type of post-treatment sensitivity, you should contact your dentist so they can determine if the level of symptoms you have experienced falls within normal expectations. Doing so also gives them an opportunity to make a treatment recommendation, if needed.

Home remedies.

In most cases, this type of discomfort is self-limiting and will usually subside within just a few days.

As treatment, your dentist may recommend the use of over-the-counter anti-inflammatory pain medications such as ibuprofen (Motrin®) or aspirin as a remedy.

  • The medicine's analgesic effect helps to control your pain.
  • Its anti-inflammatory properties help to resolve your tooth's underlying condition.

(In all cases you must read the labeling found on any drug you consider taking, so to make sure it is an appropriate medication for you.)


Preventing whitening side effects.

Picture of anti-inflammatory pain relievers.

Taking an anti-inflammatory medication can help with bleaching-treatment sensitivity.

Anti-inflammatory medications.

It may be possible to minimize your potential for tooth-related treatment side effects by taking an over-the-counter anti-inflammatory drug (ibuprofen, aspirin) prior to having your in-office treatment.
Ask your dentist for their advice and a dosing recommendation. (In all cases you should read the labeling found on any drug you consider taking, so to make sure it is an appropriate medication for you.)

Desensitizing toothpaste.

Some dentists recommend the use of desensitizing toothpaste (discussed above) for two weeks prior to having whitening treatments as a way of minimizing your potential for experiencing complications with tooth sensitivity and discomfort.

What are the safety concerns associated with professional-grade tooth whiteners?

The peroxide-based tooth whiteners used with in-office treatments are formulated using the same types of compounds as at-home products. Collectively, these agents are called peroxides and we've created a page that discusses the general safety concerns associated with their use.

There are a couple of factors that make in-office bleaching technique totally unique and, as a result, modify which issues are of the greatest concern.

  • The peroxide content found in professional whiteners is typically much higher, possibly 10 times so. (Which tends to increase concerns about some issues.)
  • But this technique employs steps to ensure that the whitener is only applied to the patient's teeth. It's not in contact with soft oral tissues. None of it is swallowed. (This, in a very big way, removes concerns about systemic issues completely.)

Use the links above for more information.


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