You should visit the dentist bi-annualy for regular cleanings and check-ups. Plaque and biofilm build up on the teeth over time and only dental professionals have the proper equipment to clean off the hard plaque that builds up. Also, if you are not brushing or flossing properly, it is good to see a dentist to make sure you are correcting any mistakes, so you can prevent future cavities from happening. Now, in between dental visits, a good way to know if you should visit the dentist is if you have any of the following symptoms: Mouth sores, jaw pain or a swollen jaw, broken teeth, severe sensitivity, headaches or earaches and a bump or abscess on any surrounding gum area of the teeth. These are clear signs that you may have a cavity, a bad tooth or even an infection in your mouth.