The main factor appeared to be saliva. Saliva is required to clear food away from the mouth. The mouth is the driest at midnight. Researchers concluded sugary and acidic food and drinks are more harmful to your teeth late at night than other times of the day.
Researchers found brushing teeth twice a day with fluoride toothpaste can help in preventing teeth damage. They also say it's important to drink water right before you go to sleep.
The findings appear in the Journal "Eating Behaviors".