One of the questions we’re often asked by patients fed up with their tired-looking smiles is “how does teeth whitening work?” But before getting down to the nitty-gritty of teeth whitening, let’s take a closer look at the anatomy or structure of a tooth and meet the enemy – tooth staining.
The structure of a tooth
Teeth are made up of various layers. At the core of a tooth lies what is known as the dental pulp. This contains a system of nerves, blood vessels, and connective tissues that is protected by a hard layer known as dentin which, in turn, is protected by a layer of tooth enamel.
you consume food and beverages or smoke cigarettes, another layer gradually forms over the enamel. In essence, foreign residue accumulates forming a pellicle film or membrane on top of the enamel layer.
The good news is that a dentist can remove much of this film by scraping the teeth with special instruments. Even brushing your teeth with abrasive teeth whitening toothpaste will help remove some of the film as this works in a similar way to scrubbing a pan with an abrasive scouring pad to remove food debris.
The issue is that the pellicle layer never really goes away and stays on the teeth for years. As a result, foreign material can penetrate the enamel entering via microscopic pores. This also means that staining agents can weave their way deeper into the tooth where they can’t simply be scoured away. While the deeper stains are harmless enough, people often find them unattractive. This is where teeth whitening comes into play.
So, how does teeth whitening work?
In basic terms, teeth whitening treatments contain bleaching chemicals that penetrate the tooth enamel through the pores setting off a chemical reaction or more specifically, an oxidation reaction, breaking down any stain molecules or compounds.
As a result, dark stains become less apparent and the teeth look noticeably cleaner and brighter.
The majority of whitening treatments use one of two bleaching agents – carbamide peroxide or hydrogen peroxide – yes, the same stuff you bleach your hair with. When it’s used on teeth, carbamide peroxide breaks down into hydrogen peroxide and urea- a colourless crystalline compound with the active bleaching agent being hydrogen peroxide.
There are a few ways to initiate this process. The one that we’re going to talk about in this post however are the treatments that dentists provide – professional teeth whitening!
Dentist supervised teeth whitening treatments
Basically, these whitening treatments involve the use of hydrogen or carbamide peroxide tailored to the needs of an individual patient. This can be in the form of chair-side teeth whitening carried out by the dentist in their practice or take-home whitening kits provided by the dentist for patients to whiten teeth themselves in the comfort of their home.
Before any treatment can take place, a dentist will ensure the patient’s mouth is healthy i.e. free from tooth decay or gum disease and give the teeth a clean to achieve optimum results.
Dentists in Australia typically use teeth whitening products containing up to 35 per cent hydrogen peroxide which produces greater results in a short time. The in-office procedure involves the dentist cleaning the teeth and then applying a protective barrier to the gums to protect them from the bleaching agent. The whitening gel is then applied, left for several minutes and rinsed off. This may be repeated several times depending on the product being used. Teeth can be lightened by up to six shades of whitening within a one-hour appointment.
Take-home whitening treatments – how they work?
At-home teeth whitening systems (those provided by your dentist) often contain 10-20 per cent carbamide peroxide as well as other ingredients such as sodium hydroxide, carbomer, glycerine and flavouring agents. Higher-strength kits may also contain sodium fluoride to help reduce sensitivity and strengthen the teeth.
Before starting their treatment, patients will be issued with custom mouth trays to ensure that the whitening gel comes into contact with all of the surfaces of the teeth and is not touching the gums. A thin ribbon of gel is placed into the trays which are then worn over the mouth for 90 minutes during the day or overnight while you sleep. Results can usually be seen within 10-14 days.
Benefits of dentist-supervised teeth whitening
- The dentist can determine if teeth whitening is a suitable treatment for a patient and will be effective
- They can help a patient choose from chairside or take-home whitening
- They can adjust the concentration of the gel for patients with sensitive teeth
- They can discuss other cosmetic dental options to enhance the smile to help a patient achieve their smile goals
On the downside, professional teeth whitening costs more than store-bought products and it can take a while to get started – waiting for an appointment or customised trays to be created.
That said, dentist-supervised teeth whitening is safe, reliable and long-lasting so it’s worth waiting for!
Hopefully, this post has answered your question “how does teeth whitening work?” and motivated you to have a discussion with your dentist about achieving a whiter smile.
If you’d like to know more about teeth whitening and whether it’s a suitable treatment for you, why not schedule a consultation with the friendly experienced team at Beyond Dental Care. Get in touch today.