Cavities, also known as dental caries or tooth decay, are caused primarily by the interaction of bacteria in the mouth with sugars and starches from food and drinks. Here is a detailed explanation of the causes:

• Bacterial plaque and acid production: Bacteria such as Streptococcus mutans live in the mouth and form a sticky film called plaque on the teeth. These bacteria feed on sugars and fermentable carbohydrates from the diet and produce acids as a byproduct. The acid dissolves minerals in the tooth enamel, leading to enamel erosion and the formation of tiny holes-early cavities

• Poor oral hygiene: Not brushing and flossing regularly allows plaque and tartar to build up, increasing acid production and the risk of cavities. Inadequate brushing time and not using mouthwash or cleaning the tongue also contribute

• Frequent consumption of sugary and starchy foods: Foods and drinks high in sugar, such as candy, soda, dried fruit, ice cream, and starchy foods like bread and cereals, provide fuel for bacteria to produce acid. Frequent snacking or sipping sugary drinks prolongs acid exposure, increasing cavity risk

• Tooth anatomy and enamel quality: Back teeth (molars and premolars) have grooves and pits that trap food and are harder to clean, making them more prone to decay. Some people have naturally weaker enamel or deep crevices that facilitate plaque buildup

• Dry mouth: Saliva helps neutralize acids and wash away food particles. Conditions or medications that reduce saliva production decrease this protective effect, raising cavity risk

• Other factors: Teeth grinding can wear down enamel, gum recession exposes more tooth surface to decay, and lack of fluoride weakens enamel resistance. Also, babies fed sugary liquids at bedtime are at risk of "baby bottle tooth decay"

In summary, cavities are caused by acid produced by bacteria feeding on sugars and starches, combined with factors that promote plaque buildup and reduce enamel protection. Maintaining good oral hygiene, reducing sugary food intake, and regular dental visits help prevent cavities