How Does Tooth Whitening Work?

Teeth whitening can remove both extrinsic and intrinsic stains. This means stains on the surface of your teeth and the stains that lie inside the tooth, below your tooth enamel. The bleaching agent found in teeth whitening products is usually hydrogen peroxide or carbamide peroxide, and these chemicals work to break down the stains on your teeth, lightening them over time. A professional teeth whitening procedure at the dentist will help to remove both types of stains, whereas teeth whitening at home using an over-the-counter product will only be effective at improving surface stains. If you’ve ever wondered “how does teeth whitening work?”, it’s one of two ways: teeth bleaching or abrasion. Here is some information on both methods. 

Teeth bleaching procedures lighten your natural tooth colour, and can result in teeth that are three to five shades brighter. Professional teeth whitening at the dentist and at-home tray whitening both rely on bleaching. The bleach used contains an active ingredient, most often carbamide peroxide or hydrogen peroxide, in high concentrations, which helps remove both surface stains and the discolouration that lies below your tooth enamel.

Non-bleaching procedures work by using a physical action to help remove surface stains. Even the act of brushing your teeth every day uses mild abrasion to gently remove surface stains. Choosing a whitening toothpaste that has special polishing agents can provide additional stain removal and leave your teeth looking clean and bright. Professional cleaning by a dentist or hygienist also uses abrasion and polishing to remove most external staining caused by food and tobacco. Not only that, a professional cleaning treatment can remove the plaque and tartar that is too tough for brushing to remove. Keep in mind that some abrasive products can be too harsh for your teeth, for example, baking soda or charcoal toothpaste, and may end up damaging your tooth enamel.

There are many ways to get a whiter smile, and the best method for you will depend on your budget, lifestyle and how long you want your results to last for. Some methods are more costly, and some take more time and effort. Whatever teeth whitening procedure you choose, make sure it’s the right one for you.

In-office laser whitening is the most effective teeth whitening procedure and can deliver great results in the shortest time; however, it’s also the most expensive way to get white teeth. Your dentist will protect your gums and apply a gel containing a high percentage of whitening agent to your teeth before using an LED light or laser to accelerate the process. Your dentist will also take care to protect your gums using a shield or protective gel, making this the safest way to get a whiter smile. A professional teeth whitening treatment usually lasts around 60 minutes, and you’ll notice a difference after just one session. As this treatment penetrates your enamel and also lightens the dentine underneath, your results are also likely to last for longer.

Another popular professional teeth whitening treatment is to have your dentist take impressions of your teeth to make custom-fit trays. Having trays that are made to fit your teeth exactly is much more effective than using the one-size-fits-all trays you can buy over the counter. You can then take your trays home along with whitening gel and use them a few times a week until you get your desired result. The whitening gel provided by a dentist is stronger than any product available over the counter, so this method is effective; however, it takes longer to see results compared to using laser teeth whitening. One of the benefits of this method is that the trays are reusable, so if you notice new staining, you can easily repeat the process.

If you prefer to whiten teeth at home, you may want to try over-the-counter products that can brighten your smile. In the UK, over-the-counter teeth whitening products can only legally contain 0.1% hydrogen peroxide (compared to around 6% in whitening gel from your dentist); however, they can still be effective, especially for keeping recently whitened teeth looking bright. As these products contain a low percentage of hydrogen peroxide, they can also be a great option for people with sensitive teeth and gums. Over-the-counter teeth whitening products include teeth whitening strips, whitening pens, at-home LED kits and whitening toothpaste and mouthwash. Be mindful of where you get these products and make sure you’re buying from a reputable store if you’re shopping online.

How long your teeth whitening results last will depend on how good your oral hygiene routine is, along with your lifestyle choices. Brushing your teeth twice a day and flossing once a day will help to keep your teeth free from surface stains, as will visiting your dentist twice a year for professional cleaning. You should also avoid foods and drinks that are known to stain teeth as much as possible, like tea, coffee, red wine and curries. Smoking and using other tobacco products will also cause your teeth to become discoloured quickly. If you look after your teeth, your whitening results can last up to 3 years!

Here are the answers to some commonly asked questions about having a teeth whitening procedure and how to whiten teeth at home: