Foods to Avoid for Great Oral Health, According to a Dentist in Los Angeles How often do you visit your dentist? Are you in there every six months, just before your insurance plan kicks in, or once every few years? Whatever the case may be, you’ll have better dental hygiene by simply eating the right foods and avoiding those that can cause tooth decay and other problems with your mouth. Bad Habits you should avoid: 1: Sugar We all know that too much sugar is bad for our waistlines, but did you know it’s also terrible for your teeth? Sugar is one of the leading causes of tooth decay, which is why it’s important to limit your intake. When you do eat sugary foods, be sure to brush your teeth afterwards.