Professor Laurie Walsh from UQ's School of Dentistry spoke with MSN on the effects of using home teeth whitening kits without consulting a dentist.
Professor Walsh claims more than 2.5 million people could be ruining their smiles because fillings and some teeth stains cannot be bleached with the chemicals contained in over-the-counter treatments.
A member of the Australian Dental Association, Professor Walsh says the potential side effects of home whitening products range from sensitive, discoloured teeth to chemical burns on the cheeks and gums.
'You end up looking bizarre, that would be the nicest word to describe it,' he said.
He says the most common stains, caused by drinking tea and coffee, can be easily removed with a professional clean rather than bleach.
Professor Walsh's warning follows a move by the Australian Competition and Consumer Commission (ACCC) to allow dentists to give patients stronger whitening agents in take-home kits, opening access to products from the US.