What causes tooth decay?
Tooth decay is multifactorial: It is caused by the presence of a caries-causing bacteria and a substrate such as sugar, on a tooth surface, over a period of time. Caries-causing bacteria are bacteria which break down sugars into acid, and over time, this acid can demineralise and soften tooth surfaces, causing cavities.
How can we prevent tooth decay?
Its not about how much sugar you take, but how long it spends on your teeth! Brushing and flossing often to remove sugar and bacteria will help, as will avoiding long periods of sugar/acid exposure, such as avoiding sipping on soft drinks or sucking on a lollipop. A fluoride toothpaste is also important to help to remineralise and harden the teeth. A fluoride containing mouthwash can also be helpful after brushing.