1. What is a dental cavity? (200 words or less)- Dental cavities (tooth decay) is a major oral health problem in most industrialised countries, affecting 60–90% of schoolchildren and the vast majority of adults.

The early manifestation of the cavity process is a small patch of demineralised (softened) enamel at the tooth surface, often hidden from sight in the fissures (grooves) of teeth or in between the teeth. The destruction spreads into the softer, sensitive part of the tooth beneath the enamel (dentine). The weakened enamel then collapses to form a cavity and the tooth is progressively destroyed. Caries can also attack the roots of teeth should they become exposed by gum recession. This is more common in older adults.