How Teeth Whitening Works


Truth is, teeth whitening is a more complex procedure than most people realise.  Precisely why the vast majority of those who put their faith in everyday whitening toothpaste, mouthwash and floss come out disappointed.  Whitening teeth effectively means using something much stronger than these generic oral hygiene products, with an appropriate bleaching agent.  But even then, you’ll still come across plenty of people who claim they did the job right and it simply didn’t work.

In which case, why is it that teeth whitening is more successful for some people than others?  More importantly, how exactly does teeth whitening work?

How does Teeth Whitening Work?

Teeth whitening is a process that involves exposing the teeth to a bleaching agent, formulated with a special substance that opens the pores in the teeth for deep-down penetrative cleaning. The bleach itself then gets to work on the stained or discoloured molecules of the teeth, gradually creating a brighter and whiter appearance.

Hydrogen peroxide is one of the most widely used bleaching agents, though varies significantly in terms of the amount present in the whitening product.  Used appropriately, hydrogen peroxide can eliminate almost 100% of surface stains and deeper discolouration, in order to create a gleaming white smile.

Contrary to popular belief, the quantity of hydrogen peroxide in a tooth whitening product has no bearing on its overall effectiveness.  It’s just that with a 35% hydrogen peroxide product, you’ll be looking at significantly fewer applications than you’d need with a 6% hydrogen peroxide agent.

In any case, it’s recommended that stronger products (those with more than 20% peroxide) be used exclusively under the supervision of a dentist.  The potential consequences of whitening agent misuse include severe tooth sensitivity and even chemical burns in extreme cases.

Tooth Sensitivity

Tooth sensitivity is anything but a rare dental health complaint.  In fact, it’s estimated that around two-thirds of all adults (66%) experience tooth sensitivity to some extent during their lifetime.  Where tooth sensitivity is an issue, it is important to discuss teeth whitening with a qualified practitioner, before going ahead.

This is because one of the known side effects of teeth whitening (depending on the chosen approach) is temporarily heightened sensitivity. As the pores of the teeth are opened by the agent and subsequently take some time to close, a period of heightened sensitivity (two hours to 48 hours) is the norm.  This isn’t usually an issue for most people, but can make things uncomfortable for individuals with sensitive teeth.

In any case, desensitising gels are available to ensure a more comfortable and pain-free process, if sensitivity is likely to cause an issue.  Desensitising gel actively recloses the pores when applied directly to the teeth, which along with reduced sensitivity brings the added bonus of protecting the newly whitened surface from subsequent stains.

Tooth Whitening Applications Required

How many applications are necessary will vary in accordance with the strength of the product and the age of the user. DIY teeth whitening kits will include detailed guidelines in the manufacturer’s instructions, though it can be useful to consult with a dental practitioner if in doubt.

Here’s how may tooth whitening applications will usually be required in a typical case:

Ages 14-25                        Ages 26-40                             Ages 41+

3 syringes of gel                 4-6 syringes of gel               7-9 syringes of gel

3-9 applications                7-14 applications                    40+ applications


Unfortunately, it is impossible for any responsible dentist to guarantee a 100% bright and white smile.  For one thing, teeth are not naturally brilliant white – nor does blinding whiteness always indicate good oral health.  Secondly, each and every person’s mouth is 100% unique – the natural colour of one person’s teeth could be completely different than that of the next.

It is therefore important to have realistic expectations if undergoing a whitening treatment.  Effective teeth whitening will certainly improve the appearance of your smile, though cannot be counted on for flawlessly white teeth.

At Admire Dentistry, we’re committed to offering honest and impartial advice on all aspects of dental health and cosmetic improvements for teeth. We offer a wide variety of services at our independent Family Dental Clinics, where our friendly practitioners are standing by to answer your questions and address your concerns. Call anytime to discuss any aspect of teeth whitening in more detail, or pop in anytime to meet us in person.