Teeth Whitening
This factsheet is for people who are planning to have their teeth whitened, or who would like information about it.
Tooth whitening is a way of lightening the natural colour of teeth using bleaching methods. Tooth colour varies among people.
Teeth can become discoloured through red wine, coffee, smoking and age.
Your care will be adapted to meet your individual needs and may differ from what is described here. So it's important to follow your dentist's advice.
• About tooth whitening
• What are the alternatives to tooth whitening?
• Getting advice about tooth whitening
• About tooth whitening products
• How long will the whitening last?
• When not to have tooth whitening
• Side-effects of tooth whitening
About tooth whitening
There are a number of different methods of whitening teeth. You can buy bleaching kits from chemists to use at home, or your dentist can do it. The products contain hydrogen peroxide or carbamide peroxide. As these chemicals break down, oxygen gets into the enamel on the teeth, lightening them. Dentists can also bleach teeth using a laser.
As you get older, your teeth can become darker naturally. This process is often increased by drinking tea, coffee, red wine or other food and drink with strong colourings. Another major cause is smoking, which can make your teeth appear yellowed. Tooth decay, fillings and tartar build-up can also contribute to discolouration.
If the nerves and blood vessels in teeth are damaged through decay or a knock, the tooth may become darker.
Some types of staining can be caused by diseases or medicines. For example, if a type of antibiotic called tetracycline is given to children whose teeth are still developing, their adult teeth may form with a yellow or green tinge.
What are the alternatives to tooth whitening?
Simple ways to improve the appearance of discoloured teeth include:
• regularly having your teeth scaled and polished to remove any tartar that has built up
• following advice about preventing tooth decay
• brushing regularly
• stopping smoking
• cutting down on strong-coloured food and drink to stop stains returning
Whitening toothpastes are slightly abrasive, which may help to remove surface staining, but they don't alter the natural shade of your teeth. Experts are currently reviewing how effective whitening toothpastes are.
Your dentist can give you advice about replacing your metal fillings and crowns with tooth-coloured ones.
Veneers
This is when a thin layer of tooth-coloured material, usually porcelain, is fitted over a discoloured tooth.
On the first visit, you may have a local anaesthetic injection to numb your tooth, but this isn't always necessary. The surface of your tooth may be filed down slightly to allow for the added thickness of the veneer, so bear in mind that it can't be reversed. Your dentist will then take a mould of your tooth in a putty-like material. This is sent to a laboratory where the veneer is made by a dental technician - this can take one to two weeks. While you're waiting, you may have a slightly roughened, sensitive tooth.
On the second visit, your dentist will bond the veneer onto the front of your tooth.
Although veneers can last for many years, they can be damaged through an accident, break or chip and may need to be replaced. The edge of a veneer may be fragile, so try not to bite your nails or other hard materials, such as ice, or tear sticky tape with your teeth.
Getting advice about tooth whitening
Your dentist can give you advice about the different bleaching methods and what will be the most effective for you. For example, the colour that your teeth are now will affect how well bleaching works. You also need to consider your skin complexion so that the treatment looks as natural as possible.
Home kits may not be suitable if you have damaged nerves causing discolouration. You may need stronger products that can only be used by a professional.
It's important to remember that if you have tooth-coloured fillings or bonding material, these won't bleach, and if you bleach your teeth, they will be a different colour. In this case, veneers may work better.
About tooth whitening products
Over-the-counter kits
Over-the-counter (OTC) kits are sold in most major pharmacies throughout the UK. They usually contain rubber mouth trays (moulds that are approximately the same shape as your teeth) and tubes of bleaching gel.
After squeezing some of the gel into the mouth trays, you place them over your teeth, usually for about 30 minutes at a time.
The bleaching ingredient in the gel is usually hydrogen peroxide. The kits should only contain weak hydrogen peroxide, and aren't as effective as stronger products that may be used by your dentist.
Always check the level of peroxide on the packaging. The permitted hydrogen peroxide and carbamide peroxide content for tooth whitening products is just 0.1 percent.
In 2008, the Trading Standards Institute discovered home kits on the market containing 100 times more hydrogen peroxide than allowed. Always buy them from a reputable source such as a major chemist and preferably one approved by the British Dental Health Foundation.
Professional tooth bleaching
In the past, tooth whitening could only be done by dentists. However, now, provided a dentist has recommended that you can have the procedure, dental hygienists and dental therapists are also able to carry out tooth whitening.
Some tooth whitening techniques are described here.
External bleaching
This is when the bleaching gel is placed on the outer (external) surfaces of the teeth. Procedures that use this technique are described here.
• Home' bleaching - this is similar to the OTC kits, but with two main differences. Firstly, your dentist makes the rubber mouth trays so that they fit your teeth precisely, and secondly, the bleaching gel may be stronger and therefore more effective. Your dentist will give you tubes of bleaching gel and instructions on how to put the gel in the mouth trays. You will need to wear the mouth trays for 30 minutes to one hour each day, for two to four weeks. It may take three to four weeks to achieve the colour that you want. Your dentist will give you detailed instructions. There is some evidence that OTC and home bleaching kits work, but some products may be better than others. Possible side-effects of home bleaching include tooth sensitivity and gum irritation. Also, the long-term effects of using these techniques aren't known. Home bleaching is only recommended when done in consultation with your dentist.
• In the dental surgery - 'power' or 'laser' bleaching. Your dentist may put a rubber seal around your teeth to protect your gums depending on the concentration of bleaching agent used. The bleaching gel is then placed onto your teeth and a special, bright light is used. This is an attempt to enhance the whitening process. The appointment may take one to two hours.
• Combined bleaching, sometimes also known as 'power' bleaching - both the home bleaching and surgery are used in combination. The home bleaching stage may occur before or after surgery - this depends on the type of treatment used. Your dentist will give you instructions.
Internal bleaching
This is when the bleaching product is put inside the tooth. Internal bleaching can only be done on teeth that have been successfully root treated. This is when blood vessels and nerves inside the tooth have been replaced with a rubber filling.
The dentist will drill a hole (if it's a front tooth, the hole will be on the back so that you can't see it) and put the bleaching product into the hole. This will usually be the hole already used for the root treatment, although it may need to be enlarged slightly. The hole will be sealed with a temporary filling, leaving the bleach inside the tooth. The procedure won't hurt because the tooth has no nerve inside it.
You will have to go back to your dentist about a week later to have the temporary filling and bleach taken out. If you're happy with the new shade, your dentist will fill the hole with a tooth-coloured filling. Sometimes, the colour hasn't lightened enough and the process needs to be repeated.
Occasionally, internal bleaching needs to be combined with other whitening techniques to achieve the desired effect.
How long will the whitening last?
The whitening effects of different bleaching methods can last for up to three years, but this varies from person to person. Research on 'home' bleaching treatments prescribed by a dentist has found that for people who achieved a lighter shade, only half of them still had whiter teeth six months later. Your eating, drinking, smoking and brushing habits may have an effect on how long the treatment lasts.
It's important to bear in mind that bleaching doesn't always result in the whiteness that you expect. The results vary from person to person and depend on the shade of your teeth before bleaching. Therefore, it's important to discuss all the possible options for improving the appearance of your teeth with your dentist before you make a decision.
When not to have tooth whitening
There are some instances when a dentist may recommend that you don't have bleaching. For example, if you have tooth decay, this should be treated before starting any whitening treatments. Similarly, your gums should be healthy so if you have any gum disease, this needs treating first.
If your teeth are extremely sensitive to hot and cold food or drinks, bleaching may not be recommended.
Some types of staining, such as tetracycline antibiotic staining, don't respond to bleaching as well as others. Bleaching, if successful, may take longer on tetracycline-stained teeth.
Bleaching won't work on false teeth, crowns, veneers or fillings (including tooth-coloured fillings). Instead, your dentist may be able to replace these with lighter ones.
Bleaching isn't usually recommended for pregnant or breastfeeding women, or for anyone under the age of 18 whose teeth are still developing.
Side-effects of tooth whitening
All dental treatment carries a risk of side-effects, which are the unwanted, but mostly temporary effects you may get after a procedure. Side-effects include temporary sensitivity of the teeth to hot and cold, a sore throat, tender gums and white patches on your gums. These side-effects should disappear after a few days. Contact your dentist if the symptoms persist.
There is no evidence to suggest that tooth bleaching is harmful to the gums, but it isn't clear what the long-term effect on the nerves and blood vessels inside the teeth are.
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