As a dentist I hear this very often. I am too old for cavities doc! In reality you are never too old for cavities. So you have to take good care of your teeth no matter how old you are. There are a lot of factors contributing to tooth decay.
Genetics has its roll in the fact that some people have a stronger enamel tooth surface (the outer layer of the tooth) than others. Today, Fluoridated water and Fluoride supplements given to children under 12 help build a stronger enamel structure and consequently less cavities in the new generation. So ingesting Fluoride is helpful if you are a child. Once the tooth structure is formed ingested Fluoride doesn’t help. However any topical application of fluoride can strengthen the enamel of your teeth no matter how old you are. That is why most toothpastes on the market have Fluoride in it. You can also buy fluoride rinses over the counter or you can have your dentist professionally apply a stronger version while you have your teeth cleaned.
Although most of the adult population doesn’t need professional application of Fluoride on their teeth, there are some at higher risk of developing decay. This includes teenagers ( where unhealthy dietary habits like drinking too much soda, or sports drinks can make them more prone to decay ) , persons on a high carbohydrate diet, persons wearing braces or persons wearing removable partial prosthetic appliances ( partial dentures),or persons on medications that cause dry mouth ( will talk about this in a future article) , for this patients we recommend either an in office Fluoride application or a prescription fluoridated toothpaste.