Cavities are primarily caused by bad dental habits, including diets high in sugar and acids, use of tobacco products, and poor oral hygiene. However, people who take excellent care of their teeth also get cavities—sometimes even more than those without a good oral care routine. If you get cavities more easily than others, genetics may partially be to blame. 

Several uncontrollable factors can make you more susceptible to cavities. Here are a few of the most common:

• Tooth Structure. Genes affect tooth formation. Teeth that naturally have lots of ridges, pits and grooves can more easily trap food particles and bacteria. The amount of protective enamel your teeth have is also driven by genetics. 
• Tooth Spacing. Teeth that are crowded together make it much easier for plaque and bacteria to hide...and that much more difficult to remove them by brushing and flossing.
• Low Saliva Production. Saliva washes away bacteria and neutralizes acids that can attack your teeth. The amount of saliva your mouth produces is influenced by your genes, but medication, diet and other factors can also contribute.
• Gene Variation. Some people have an individual variation of a specific gene that helps fight germs in the body. If present, the variation could make you up to five times more likely to get cavities.

While you can't control your genes, you can minimize your risk of tooth decay by practicing good dental hygiene. Brushing, flossing and regular dental checkups provide the best protection against cavities—regardless of their cause.