Teeth whitening is a great dental tool to have at your disposal. Whether you choose to go the in-office route or do it yourself at home, whitening can restore vitality to your smile. However, as well as brighten your smile, a whitening treatment can also reveal things that you previously didn't know were there.

Craze lines, white spots and even horizontal lines are all common discoveries that patients make after a whitening session. If you have just finished a whitening session and now have horizontal lines on your teeth, the cause could be one of two things.

Your Teeth Are Dehydrated

When you whiten your teeth, the bleach (hydrogen peroxide) causes your teeth to become dehydrated. Normally, in your waking hours, teeth are always well hydrated because they are in contact with saliva. However, once teeth go without saliva for a prolonged period, for example, when you are sleeping, white spots or even lines may appear on their surface.

Since whitening dehydrates your teeth and whitens them, those dehydration spots and lines will be even more visible than they normally are. It may take a few hours to a day or two before the lines fade completely. In the meantime, drink plenty of water and refrain from activities such as running or sleeping with your mouth open.

It Could Be Hypocalcification

If dehydration is not to blame for the white lines on your teeth, the only other clear culprit is hypocalcification. Unfortunately, this condition occurs just before the formation of cavities. The acid produced by the bacteria that cling to your teeth, along with the acids in the foods you consume, cause teeth to demineralise.

When an area of tooth loses calcium, that area weakens and takes on a chalky consistency. The area may also appear as a white blotch or line running across the tooth. Before you whitened your teeth, the hypocalcification may not have been as apparent. Whitening, however, is known to exaggerate existing marks on teeth. In this case, you should be thankful for that.

Teeth Can Re-mineralise

Demineralisation precedes cavities. Therefore, teeth with hypocalcification should be treated quickly before a cavity can form. Fortunately, your dentist can treat affected teeth with fluoride and pastes that stimulate re-mineralisation. You should also make an effort to cut down on acidic food and drinks like soda. Xylitol chewing gum can also help to re-mineralise teeth.

If you notice white lines or spots on your teeth after whitening, book an appointment with your dentist so you can work out what is causing the issue.