People with yellowing teeth could benefit from London tooth whitening.
According to Dr Jonathan Levine, who offered a series of oral health tips to US talk show host Oprah Winfrey, some stains are genetic.
These should be dealt with by a dental professional, the website Oprah.com states.
"Some tooth stains are intrinsic – they are created internally by genetics," the website cites Dr Levine as suggesting.
"These stains need a true whitener, done in a dentist’s office."
A series of tips was also offered in order to improve dental health and avoid the need for emergency dentistry.
When it comes to brushing, people were advised to use a round-ended brush twice a day, for 30 seconds in each quadrant.
Flossing helps to clean the extra 40 per cent of each tooth that brushing can miss, while contributing to good gum health.
Mouthwash, chewing gum and eating a healthy diet were also suggested. The latter point is essential in creating a healthy pH balance in the mouth, which can help protect teeth.
According to Andrea Markowitz, of Health Key, said tooth whitening can help people appear younger.