People considering London teeth whitening have been urged to seek professional treatment.
Medical experts have advised people to avoid at-home teeth whitening procedures which could be dangerous if used incorrectly.
This news comes after a woman in New Zealand was left in extreme pain and with bleached gums for more than a day after receiving treatment from an unqualified practitioner, the Sunday Star Times reports.
The country's Environmental Risk Management Authority has called for a meeting to propose a ban of over-the-counter tooth whitening kits containing more than 3.6 per cent hydrogen peroxide.
Experts also warned that undergoing teeth whitening procedures too soon after polishing treatments could be harmful to teeth and recommended that patients wait for two weeks.
Meanwhile, website Make My Teeth Whiter has suggested people use whitening toothpaste to bring out the natural shine of their smile.
The toothpaste contains mild chemicals to remove light stains on the teeth.