Currently, there are only three types of lasers that have been approved by the FDA for laser teeth whitening. These are argon, carbon dioxide and diode lasers. The type of lights used for the procedure have various wavelengths and can have different effects on the bleaching process, so it is never a bad idea to ask a dentist about what type of technology is being used. While these lasers are considered safe to use under the professional guidance of a dentist, some patients may experience increased sensitivity during or following the treatment.