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How Does UV Light Whiten Teeth And What Are The Risks?

How Does UV Whiten Teeth

Ultraviolet (UV) light has been used for many years to aid teeth whitening, but how does it actually help the tooth whitening process? If you are considering a tooth whitening procedure, you should be aware of the associated health concerns of UV light and that there are safer alternatives available.

Teeth whitening is one of the most popular cosmetic dentistry procedures requested – patients desire that Hollywood smile to give them a celebrity-like glow. In-surgery teeth whitening usually involves exposing the teeth to the ultraviolet (UV) light which results in an increase in tooth temperature. According to dental care professionals that offer this kind of procedure, this can speed up the breakdown process of the hydrogen molecule which whitens the teeth, but it can be detrimental to your oral health.

How It Works

Teeth whitening procedures can be extremely successful, often lightening your teeth by up to 8 shades. But the truth is that on its own, UV light does not whiten your teeth. That means that no matter how much smiling you do on a sunny day, your teeth won’t get any whiter – and any whitening you notice will probably be the effect of getting a tan, but that has its own risks. So why is UV light used by dentists and home whitening kits alike?

The tooth whitening process uses a whitening agent, usually peroxide-based, which is applied to your teeth. Your teeth are then traditionally exposed to UV light, also known as UV radiation. It is thought that the UV light activates the hydrogen peroxide by acting as a catalyst, meaning it can speed up the reaction to help you get whiter teeth faster, and to get those results quicker. Studies such as this, from 2003 found that light combined with peroxide significantly lightened the color of teeth to a greater extent than peroxide or light alone did.

Safety Concerns Of UV Teeth Whitening

UV Light Risks

The US FDA has logged a number of complaints of patients claiming to have suffered burns from the UV radiation. Given that your oral tissues are very sensitive and that UV radiation from the sun is known to cause skin burns and damage, this should not be a surprise. A study in 2013 found that oral tissues are also at significantly higher risk of UV-induced cancer than skin cells, and exposure to UV teeth whitening can also induce flare-ups of lupus.

Incorrect use of the UV light, including using the lights for too long and wrongly directing the light source, can also cause damage such as cataracts in your eyes, as well as damage to your lips, gums and tongue. This, therefore, means that if you are keen to have a UV teeth whitening treatment done, it is best to go to your dentist, who will be trained to use the UV lamps in the safest possible way. They will know how long to expose your teeth to the UV source and will provide you with personal protective equipment to shield your eyes, for example. On the other hand, if you are keen to whiten your teeth at home, it is worth considering a kit that uses blue LED light instead.

These are some of the risks associated with UV teeth whitening:

Short-Term Adverse Effects

  • Burnt gums
  • Bleeding gums
  • Inflammation of the mucus membranes of the oral cavity
  • Facial sunburn
  • Increased tooth sensitivity

Long-Term Adverse Effects

  • Oral soft tissue lesions
  • Reduced color stability
  • Premature wear-and-tear of enamel
  • Abnormal growths in and around the eyes
  • Increased risk of skin or oral cancer

Safer Alternatives To UV Teeth Whitening

UV Alternative

With the risks and dangers of UV radiation now well-known, safer alternatives to UV teeth whitening have been developed. These different whitening products and methods produce a wide range of results:

  • Whitening toothpaste – these are more abrasive than regular toothpaste. They don’t contain bleach, but they help to remove surface stains and discoloration. They can lighten your tooth color by about one shade.
  • Whitening strips – these are sticky strips of plastic that are coated in hydrogen peroxide or a similar bleaching agent which you stick to your teeth. They are disposable, and you simply stick them on your teeth for a certain amount of time.
  • Blue LED kits – these are a similar design to the UV teeth whitening you get at your dentist, but the wavelength of blue LED light will not damage your teeth. They are designed to be used at home by untrained users. You can ready more about these home kits and see our reviews here.

Be mindful that there are many dubious ‘natural’ methods people use and promote to whiten teeth, such as brushing with activated charcoal, or baking soda. These methods are unproven, may make your tooth discoloration worse and are potentially harmful to your teeth and gums.


Whichever tooth whitening method you choose, bear in mind that the UV radiation is not the only risk. Most of the methods involve putting some sort of bleaching agent in your mouth, and this can cause damage and discomfort if you are not careful. No matter whether you opt for at-home or professional whitening, it is always best to follow the advice of your dentist or dental hygienist. Get your teeth checked by a dentistry professional before you whiten them to make sure they are in good condition, and always follow the instructions carefully to make sure that you don’t overtreat them.