Over time, everyone will notice some form of discoloration on their teeth. This can range from the teeth losing their shine and brightness to the appearance of stains and a total change in color.
The main reasons for this change are explained below.
Drinks and food
Food and drinks with high color pigments such as red wine, tea and coffee are some of the major contributors. The pigments attach to the enamel of the tooth (the white outer area) and cause discoloration.
Nicotine and tar, two major components of tobacco, cause staining. Tar is a black substance; nicotine, when mixed with oxygen, becomes a yellowish-brown substance.
As we age, and due to normal everyday function and wear, the tooth enamel becomes thinner. Dentine, which is the inner layer and which is more yellow, will start to show more.
Trauma to teeth
Sometimes, teeth that go through trauma (for example, a blow to the face from an accident or a fall) undergo color changes. These changes may be due to a natural process where more layers of dentine is placed on the tooth, or simply because the tooth dies.
Some medications, such as certain antihistamines, blood pressure medications and antidepressants, can cause tooth discoloration.
Also some antibiotics, such as tetracycline, when given at a young age, can cause staining and discoloration of teeth.
Radiation therapy and chemotherapy can also contribute to darkening of the teeth.
How Does Teeth Whitening Work?
Teeth whitening involves the use of bleaching substances (mainly hydrogen peroxide and carbamide peroxide) to break stains into smaller particles, making their color much less noticeable and therefore your teeth appear whiter.
Does Whitening Work on All Teeth?
Teeth respond differently to whitening. While some yellow teeth with superficial stains respond well to whitening, some with deeper stains (particularly brown and grey teeth) won’t respond as well. It is important to know that dental restorations (i.e. veneers, crowns and fillings) will not respond to whitening.
How is teeth whitening done?
There are two main pathways of teeth whitening:
Bleaching done in the dental practice
This procedure is called in-chair whitening and usually requires only one visit. The dentist will first protect your gums with a special product and then apply the whitening gel to your teeth. This procedure will be done 3 to 4 times and usually takes about an hour to complete.
Take-home teeth whitening
In this method, a custom-made tray is made for you after impressions are taken. Your dentist or the dental team will give you instructions on how to place the whitening gel in the tray and for what length of time. This method delivers slower but similar results to in-chair whitening, and bleaching can be reapplied at a later time as desired. If done every night, desired results are normally achieved within a few weeks.
Are There Any Side Effects from Teeth Whitening?
Some people may experience some tooth sensitivity after bleaching, especially from in-chair bleaching, which uses stronger bleaching products. This effect is normally only temporary and will go away within a few days. If you experience sensitivity with the take-home method, you can slow the process by applying the gel once every few nights instead of every night.
Dr Omid Salar
Principal Dentist – Trusted Dental