London - Dazzling white smiles can be an expensive business, but a host of so-called “natural” teeth-whitening methods has become an internet craze.
Entire websites are devoted to the unlikely fruit, spices and oils which apparently promise to give you a Hollywood smile at a fraction of the price.
But can natural methods ever really whiten teeth effectively? We asked Dr Uchenna Okoye, clinical director at London Smiling Dental Group…
Strawberries
Claim: Mash up a ripe strawberry, dip your toothbrush in it and brush carefully over teeth. Within two weeks, your teeth will be whiter.
Dentist’s verdict: True.
Strawberries contain citric acid, which can weaken the surface hardness of your teeth. But they also contain the more gentle malic acid, and the riper the strawberry, the higher the concentration of malic acid compared to the more harmful citric acid.
So choose a really ripe strawberry, rub it on your teeth and just like exfoliating the skin, it does remove superficial debris. The malic acid won’t actually break down the stain molecules, but the surface clean gives your teeth a whiter appearance. A gentle and effective natural whitener.
Turmeric powder
Claim: Mix half a teaspoon of dried turmeric powder with a few drops of water and stir to create a thick paste. Dip your toothbrush in (it will be stained yellow) and clean teeth.
The usual cleaning time of two-to-three minutes is doubled, because of the time it takes to rinse the yellow from your teeth and gums. The abrasive qualities of the bright yellow spice (derived from a root) will clean your teeth.
Verdict: False
This is a recipe for disaster. The rule in dentistry is that anything that will stain a white shirt will stain your teeth. All spices stain teeth but yellow spices are the worst.
Our teeth have tiny surface pores called dentin tubules, and colour molecules – chromogens – block these microscopic holes. This is why your teeth appear dark. You need to unblock these stained pores to make your teeth appear whiter – but turmeric would just penetrate them.
Orange pith
Claim: The white part of the orange skin, between the surface and the flesh of the fruit, contains d-limonene, which can help remove stains from your teeth after using it for three weeks. Peel the orange, keeping as much of the pith as you can.
Rub the white part of the peel over your teeth, and let the juice sit on your teeth for three-to-five minutes. Brush your teeth thoroughly to clean away pulp and peel, and after several weeks the chemical will have whitened the appearance.
Verdict: False.
The advice I give all my patients is to be very wary of fruit juices and to drink them with a straw (if they have to drink juice).
So this claim goes against every piece of advice and scientific evidence I can think of.
The citric acid within the orange causes tooth enamel to dissolve. This erosion can lead to tooth decay, and once the erosion has reached the soft, inner layer of your tooth known as dentin, you’ll experience sensitivity and pain. Avoid.
Banana peel
Claim: High levels of potassium, magnesium and manganese in bananas can help remove stains from teeth. Simply peel a ripe banana, and rub your teeth with the insides of the peel for about two minutes. After three weeks, your teeth will have whitened.
Verdict: True.
If you rub the skin it can act as a gentle exfoliator and will remove some surface stains, but the banana will not reach inside the pores on the surface of your enamel – so no true “deep” clean will take place.
However, I like the idea that you can eat a banana and give your teeth a quick healthy buff before running off to a meeting.
Cider vinegar
Claim: Rinsing with apple cider vinegar (mix two parts of water) will make teeth whiter and protect teeth and gums from bacteria.
Verdict: False.
Cider vinegar is a favourite of “detox” devotees. Once swallowed, it mixes with pancreatic secretions in the intestines and turns alkaline, but when it hits your teeth, it is an acid, albeit a weak one.
This makes the enamel on your teeth less resistant to damage – like wetting a chalk and then scraping off the surface. A low acid level – such as the malic acid in strawberries – won’t harm your teeth. But this will buff away a deeper layer of enamel, and should be avoided.
Coconut oil
Claim: A 3 000-year-old Ayurvedic way to clean teeth is to swish a tablespoon of oil (usually coconut, sesame or olive oil) around your mouth for 20 minutes every morning. The coconut oil sticks to the oil in the cell membranes of any bacteria in your mouth, so when you spit it out, you are ridding your mouth of unwanted micro-organisms. Used by stars including Gwyneth Paltrow, who claim it whitens teeth and improves complexion.
Verdict: False.
There is no scientific evidence at all that “oil pulling”, as it’s called, will whiten teeth, or even remove bacteria.
It’s possible that the act of swishing the oil around your mouth will dislodge some bacteria or debris, so followed by a careful brushing session, your teeth may look cleaner. But no science shows that oil pulling will make your teeth any whiter.
Bicarbonate of soda
Claim: Bicarbonate of soda is a mild abrasive which effectively removes stains on teeth caused by coffee, red wine and tea.
In a cup, mix half a teaspoon of bicarbonate of soda with half a teaspoon of water, mix to form a paste, dip your toothbrush into the mixture and brush teeth for one-to-two minutes. After just a few days you will notice a difference.
Verdict: True.
Bicarbonate of soda – otherwise known as baking soda – is somehow considered natural but it is actually a chemical, and used commercially in some teeth-whitening products and toothpastes. It does effectively remove plaque and debris on the surface of the teeth to make them appear brighter, and it also can neutralise bacterial acids in the mouth.
But it is an abrasive compound and, as such, will damage the enamel protecting the teeth if used too much.
Try it three times a year to lift those surface stains, and to avoid damaging the enamel use your finger to rub it on or a flannel.
Lemons
Claim: Suck on a slice of lemon for several minutes each morning, or rinse your mouth with lemon juice squeezed into a glass of water. The acid from the lemon will deep-clean even the tiniest of molecules lodged in your teeth.
Verdict: False.
Lemons have such a high concentration of citric acid that their juice is acidic enough to corrode enamel. Lemon juice has no place in the mouth at all.
Lemons are more acidic than vinegar. Far from whitening your teeth, they’ll dissolve them away. I have seen patients who suck lemons and are left with the imprint of a lemon slice on their teeth – requiring bonding and veneering to cover it up. Avoid this at all costs – it is the same as bathing your teeth in a glass of cola.
So which is best?
Strawberries are the best natural teeth-cleaners here. They taste great, are fantastic for the teeth and contain antioxidants, which are healthy, too. Gorge on them over summer and let them naturally clean your teeth.
They won’t push out the tiny colour molecules which cause staining, but they will give your teeth a cleaner appearance without harming them.
Meanwhile, professional whitening should be done by a trained dental worker and maintained with a whitening toothpaste – and perhaps a mouthful of strawberries!
Daily Mail