Get your five a day
Despite their red colouring, strawberries can be a natural teeth whitener. A study from the Padjadjaran Journal of Dentistry found that strawberry juice had a whitening effect on teeth stained by coffee. “The key thing is that strawberries contain malic acid, which whitens the teeth,” says Dr Richard Marques, a celebrity dentist. The same goes for apples, which not only contain malic acid, but a lot of water, which helps wash away leftover food and residue on the teeth. Hard, crunchy vegetables such as carrots and celery also have a cleansing effect, says Marques.
Eat some cheese
Eating cheese is another way to clean your teeth and keep them white, while the natural minerals it contains can strengthen your enamel. “It’s got calcium in it for a start, which is really good for your teeth,” says Marques. “Whiter cheeses are better”, with cheddar being one of the most effective because the rest of its cleansing properties lie in the hard surface structure, meaning that softer cheese such as brie and blue cheese do not give the same results.
Practise good oral hygiene
The simplest and most effective way to maintain whiteness is to practise good oral hygiene. At a minimum, this means brushing for the required four minutes each day – two in the morning and two in the evening. “There is some evidence that powered toothbrushes are better, particularly the ones with the small heads, but if you have a good technique, it doesn’t matter what you use,” says Prof Damien Walmsley, a scientific adviser to the British Dental Association. Take time to brush all the corners of your mouth, placing your toothbrush at a 45-degree angle to the gums. Follow up with flossing and mouthwash for even better results.
Brush with baking soda toothpaste
A comparison study in 2011 found that toothpastes containing baking soda were significantly more effective at preventing stains and whitening teeth than regular silica-based toothpastes. Mixing a teaspoon of baking soda with a small glass of water, or applying it directly to the teeth using a toothbrush, can also remove some stains. However, as baking soda is an abrasive, it can damage the tooth enamel: minimise the risk by doing this only occasionally.
Visit a professional
If your teeth are more severely stained, you will need to visit a dentist to get them whitened. They will apply a carefully controlled concentration of bleach to the teeth using a tray that is moulded to fit your mouth. When having your teeth whitened with bleach, it is extremely important to go to a qualified dentist rather than visiting a beauty salon (where it is illegal) or ordering products online. “You never know what you’re going to get. Studies have found that some products contained high levels of hydrogen peroxide that can be very damaging for the enamel,” says Walmsley.