How much sugar does one have to eat to cause a tooth infection?

Tooth Decay: Tooth decay develops when acids break down the tooth enamel. These acids are excreted by bacteria stuck to your teeth. The key to helping prevent tooth decay (and infections) is to brush and floss correctly twice a day and to visit your dentist regularly. People with poor oral hygiene are more prone to caries and periodontal disease.

Less is better: But almost all foods contain carbohydrates. Bacteria take these sugars, convert them to acids, and the acids cause calcium to be etched out of the tooth enamel. Some sugars, starches, are more easily converted than others. Brush & floss twice daily with a fluoridated toothpaste. See Dentist at least twice a year to prevent small problems from becoming big ones.