Many people are nervous about going to the dentist, because they don't like to have their mouths poked and prodded. However, the minor inconvenience of a biannual cleaning is much less invasive than the root canal that will come if you don't take care of your teeth. Going to the dentist twice a year is the best way to keep a healthy set of teeth.
A toothbrush should be replaced every three to four months. If your toothbrush's bristles tend to become frayed before the three to four months, you will need to replace your brush sooner. As soon as you notice the bristles fraying, you should discontinue use and go purchase a new toothbrush.