Whitening toothpastes, DIY bleaching products and treatments from your dentist may help bring back that white, bright smile. We check out the options and tell you about their pros and cons.
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There are 2 types of stain: surface and intrinsic (deep) staining.
Surface stains: These are mainly caused by over-indulgence in tea, coffee, red wine and cigarettes. The stains attach themselves to the pellicle (a thin layer of protein from saliva that forms on your teeth every day) or take hold in the pores of tooth enamel.
Intrinsic stains: These are changes in the structure of the tooth itself. There are 4 common causes:
Whitening toothpastes claim they contain additional abrasives and polishes to make the brushing action more effective. Some also have ingredients to remove staining material or to chemically alter stains so they're less able to stick to your teeth.
Australian and UK consumer organisations have conducted user trials of these products. After 4 weeks, half the Australian triallists and three-quarters of those in the UK felt their teeth were somewhat whiter. The UK report noted, however, that some of the positive results could be because the triallists brushed their teeth for longer - the full 2 minutes demanded by the trial.
The abrasive ingredients in whitening toothpastes aren't likely to damage tooth enamel.
Whitening toothpastes should remove some surface staining, but they won't lighten the natural colour of your teeth and they're usually more expensive than other toothpastes in the same range and pack size. Simply brushing your teeth for longer with an ordinary toothpaste may well achieve the same effect.
You can buy products to bleach your teeth whiter over the counter at a pharmacy or online. They use hydrogen peroxide (or carbamide peroxide, which breaks down to hydrogen peroxide) to bleach stains and the tooth itself.
An overview of bleaching product user trials by Australia's Cochrane Collaboration found that these products work better than a placebo or no treatment. The trials covered tray, strips and paint-on-gels.
Bleaching may cause gum irritation and sensitivity to heat or cold, although these side effects go away soon after you stop the treatment.
Bleach can also penetrate cracks or cavities in your teeth - and high concentrations can cause irreversible damage to the tooth pulp and enamel, as well as irritating the gums and lining of the mouth and weakening filling materials.
These products are more effective at removing surface stains than "whitening" toothpastes. For any significant staining, it's better to see a dentist.
Dentists use custom-made trays or in-surgery bleaching to whiten deeply stained teeth.
Your dentist should start by asking about your medical history to find out how your teeth became discoloured as different types of stains will respond differently to the treatment. Your teeth will be checked and any cavities or cracks will be repaired.
We asked members about their experiences of professional whitening.
Custom-made trays: Overall, people were pleased with the results from custom-made trays:
Depending on the bleaching product used, you wear the trays either overnight or for a short period twice daily. The overnight option is more effective - but you're more likely to feel sensitisation (although the dentist can give you a desensitising gel to alleviate this). The treatment usually lasts 10 to 21 days.
You need to have a preliminary consultation to examine your teeth and take impressions for the trays.
In-surgery bleaching: Those who had had in-surgery bleaching were less satisfied. For this treatment the dentist cleans your teeth, paints a resin over your gums to protect them, and paints a concentrated gel on your teeth. An intense light is then shone on your teeth to activate the bleach. The session takes around 60 to 90 minutes.
Most felt it wasn't good value for the money they paid:
Some dentists provide a take-home tray and gel.
Non-vital whitening: Non-vital whitening is used to treat a single tooth which has darkened after an accident or root canal work. The dentist drills into the tooth, places whitening agent inside and reseals it. One member found that the improvement was only temporary - a crown was the best solution.
Dentists can use higher concentrations of bleach because they can control your exposure to it and check the health of your teeth and gums.
Teethwhitening products that contain more than 12 per cent hydrogen peroxide are now tightly controlled.
Only dentists and registered oral health practitioners supervised by a dentist will be allowed to sell these products and treatment must be carried out by a dentist or under a dentist's supervision.
Bleaching at the dentist's gives the best results - it can lighten the colour of teeth by several shades. It's most likely to be successful where discoloration is light or evenly distributed (without dark bands or patches). It works well on yellow teeth and on brown stains, but blue-grey stains caused by tetracycline may not lighten as much as the surrounding enamel. This can make such staining appear worse than before.
Bleaching won't work on tooth-coloured fillings, veneers, or crowns.
To get rid of surface stains at home we recommend a 3-part approach:
If you have deep stains or colour changes you'll need a dentist's help. Professional bleaching will not be a permanent solution - but if you avoid foods that stain, the effects may last for up to 3 years before you need another bleaching treatment.
For very deep staining you could consider veneers or bonding, or a crown for a single tooth.
Most treatments use hydrogen peroxide to bleach surface stains, but hydrogen peroxide can irritate the gums and cause the teeth to become sensitive. Overuse of these products may even damage tooth enamel and resin fillings.
The Ministry of Health and the New Zealand Dental Council asked the Environmental Risk Management Authority to tighten the rules around the use of hydrogen peroxide in teeth whiteners. The authority (now called the Environmental Protection Authority) made the following changes, which took effect in June 2013 ...
All teeth whiteners containing hydrogen peroxide now have to carry warnings to stop using the product if you experience irritation, and not to use it for more than 14 days unless the treatment is supervised by a dentist. Because of overseas reports that children and teenagers were over-using tooth whitening strips and bleaches, the labels must also warn against children younger than 16 years using these products.
Products that contain between 7 and 12 percent hydrogen peroxide are restricted. They can only be sold or applied by a dentist, a registered oral health practitioner or a tooth-whitening practitioner.
Products that contain more than 12 percent hydrogen peroxide are even more tightly controlled. You can only buy them from a dentist or a registered oral health practitioner, and they can only be applied under the supervision of a dentist.