Tooth decay, also known as dental caries, occurs when the hard surface of a tooth is damaged by acids produced by bacteria. These bacteria thrive on sugars from food and drinks, leading to the formation of cavities. If left untreated, tooth decay can cause pain, infection, and even tooth loss. Preventing tooth decay involves good oral hygiene practices, such as brushing teeth twice a day with fluoride toothpaste and flossing daily. Regular visits to a dentist for check-ups and cleanings are also essential for maintaining healthy teeth and gums.