People who rinse their mouths out with water after brushing are more likely to need emergency dentistry, an expert has suggested.
Rinsing the fluoride from toothpaste away immediately after brushing leaves the teeth unprotected for a longer period and can increase the chances of needing dental attention.
Dr Phil Stemmer from the Fresh Breath Centre in London also advises people not to rinse their toothbrushes before use, the Daily Mail reports.
The London dentist claims there is enough moisture in the mouth without adding excess water which could limit the effectiveness of the toothpaste.
He told the newspaper: "The best routine is to brush your teeth before meals and then freshen up after eating using an alcohol-free mouthwash."
Colgate recommends people of all ages should use fluoride toothpaste to prevent decay and improve the strength of teeth.
The organisation advises people who feel they are not getting enough fluoride protection to speak to a dental professional about specialised treatments to prevent tooth decay.