Dear Dr Matfield, I recently found out that dentists use ultraviolet light in some of their techniques. Mr F Diamond Dear Mr Diamond, You need have no fear that the ultraviolet light used by dentists will cause cancer. The light they use is directed, as far as possible, on the teeth so that as little as possible falls on the inside of the mouth. Also, the danger of ultraviolet light comes from long-term repeated exposure.
Dentists use more intense light for quite short periods.
This helps to ensure that the risk of cancer from such treatments is minimal. Dear Dr Matfield, I recently quit smoking after far too many years of thirty a day. I realise that the most difficult part is still to come making sure that I do not start smoking again. However, I recently heard that, after smoking for years, the damage is already done and that I will always have a high risk of getting lung cancer. No it is not true.