How Does Teeth Whitening Work?
The job of a tooth whitening product is simple- to whiten the teeth and brighten the patient’s smile.
But how exactly do teeth whitening kits work? Here, we explain the science behind the smile.
Tooth whitening - the basics
Teeth whitening solutions come in a variety of forms. These include whitening kits, gels, powders and strips.
Regardless of how it’s packaged, the role of a tooth whitening solution is to remove surface stains and bleach the teeth to make them whiter.
Whitening should only be carried out on the prescription of a dentist. Though worryingly on the rise, DIY home whitening kits can be dangerous, uncomfortable, illegal and in most cases inferior to professional whitening treatment.
In worst-case scenarios, DIY home whitening kits can cause burns, scarring and even tooth loss if too much hydrogen peroxide (HP) is used in the product.
Though safer than DIY solutions, over the counter whitening products cannot match professionally administered treatment for results.
What is hydrogen peroxide?
Hydrogen peroxide is water (H2O) with an extra oxygen molecule (H2O2). It is a key ingredient in any effective tooth whitening kit.
The extra oxygen molecule oxidizes and gives peroxide its germ killing and bleaching power. The release of oxygen molecules penetrates the colour pigments inside the tooth, altering the shade of the teeth without effecting tooth structure.
Dentist administered tooth whitening treatments can use hydrogen peroxide at concentrations of up to 6%. Over the counter home whitening kits can currently only legally contain up to 0.1% hydrogen peroxide and therefore cannot produce as effective results.
What other ingredients are used in teeth whitening products?
Along with hydrogen peroxide, the other most common ingredient found in teeth whitening kits is carbamide peroxide.
Carbamide peroxide (CP) contains hydrogen peroxide at a ratio of 1:3. For example, a product with 30% carbamide peroxide has about 10% hydrogen peroxide.
Carbamide peroxide breaks down over a longer period of time and offers a controlled peroxide release for long-lasting results. Hydrogen peroxide in its raw form acts quickly upon contact with the teeth.
Other common ingredients found in whitening treatments include potassium nitrate & fluoride.
Potassium nitrate helps relieve sensitivity fast and usually has an effect that lasts 24 hours. It works by travelling through the enamel and dentine to the pulp chamber of the tooth to calm the nerves
Fluoride is used to provide lasting relief from sensitivity by increasing the hardness of the enamel without interfering with the whitening results.
How long does teeth whitening take to work?
The amount of time it takes for the patient’s teeth to whiten is dependent on the existing state of their teeth, the product type and ingredients, and when and for how long the patient is using the product.
In general, an effective whitening product should begin to produce visible results within a few days. How much whiter the teeth get will vary from person to person but can be anywhere between six and 12 shades.
In contrast, over the counter and DIY home whitening products can take at least a month before any improvements are visible.
How long do patients need to use their kit?
To give you some idea of how long whitening kits take to work, here is an example of patient usage requirement with Big White Smile premium whitening gel.
- Big White Smile 10% CP - for 8-10 hours (or overnight)
- Big White Smile 16% CP - for 4-6 hours
- Big White Smile 6% HP - for 1-1.5 hours
Does tooth whitening work on false teeth?
Traditional whitening treatment does not work on dentures, crowns or veneers. Any attempt to do so can damage or weaken the teeth.
This is because the acrylic used in dentures does not respond to the hydrogen peroxide or carbamide peroxide and thus cannot be altered or changed in the same way as natural teeth.
Low abrasive cleaners and soft-bristle toothbrushes should be advised for patients looking to clean their dentures along with soaking in a denture-cleaning solution.
Promoting teeth whitening to your patients
Should any patient express an interest in tooth whitening or mention staining, this is a great opportunity to raise awareness of your whitening offering and highlight the risks of buying online whitening products.
Patient interest in tooth whitening can also be gauged by including it in a questionnaire that patients can fill out in the waiting area prior to their appointment.
For more advice on how best to promote and sell teeth whitening in your practice, see our blog How to Talk Teeth Whitening With Patients.
All our most popular teeth whitening solutions, including Big White Smile, can be found at the link below.
