Cavities are caused by an accumulation of plaque and tartar on the teeth, which consists of bacteria and food particles. Over time, the build-up of these substances damages the enamel and forms holes in the teeth. These bacteria also produce an acid that breaks down the enamel and makes the underlying dentin and pulp susceptible to decay and infection.
The time it takes for cavities to develop depends on several factors, including your oral hygiene habits, how often you brush and floss, and the food you eat. Cavities usually develop over the course of several months. This is one reason why biannual dentist visits for cleanings and exams are so important. When you have your teeth checked every six months, you improve the chances of finding a cavity early, when it is most treatable, and even reduce your risk of developing one in the first place.