Can Diet Coke cause cavities?

A friend of mine who lives out of town contacted me over Facebook with a good question. She never had cavities growing up and now that she is in her 20's, she is getting a few. When she goes to the dentist, he makes her feel like she "just ate a candy store." But, this girl takes good care of herself and doesn't really eat sweets. She wondered if the 2-3 Diet Cokes she drinks during the day can cause cavities. So, can something without sugar cause cavities?

Yes, Diet Coke can cause cavities. Basically, you need four things to get cavities: bacteria (everyone has it), sugar, acid, and time. While Diet Coke doesn't have the sugar, it is really high in acid. So, let's say you have a sandwich for lunch (there is sugar in bread) and you have a Diet Coke (acid) and then you sip on your Diet Coke for an hour or two, you then have everything you need to get cavities. So, here is my advice. Have sugar, have acids, whatever, but drink water afterwards. This will rinse the acids and sugars off of your teeth. Another good trick is to chew sugar-free gum, which will do the same thing as water. Don't sip on a can of Diet Coke for a long period of time. Drink it over a shorter period of time and then have water. If you do that, use an electric brush, and floss once a day (I know it's a pain), you'll be home free.