Dental cavities, also known as caries or tooth decay, are damaged areas in the hard surface of your teeth that develop into tiny openings or holes. Cavities are caused by a combination of factors, including bacteria in your mouth, frequent snacking, sipping sugary drinks, and not cleaning your teeth well.

When a tooth dies, it means that the pulp inside the tooth, which contains nerves and blood vessels, has become infected or damaged to the point where it can no longer survive. This can happen due to various reasons, including severe decay, gum disease, or trauma, such as a tooth being knocked. A dead tooth can lead to pain, discolouration, and swelling if left untreated.