It's important to change your toothbrush every three months, according to the American Dental Association, whether or not it looks like it's needed. Appearances can be deceiving, so you want to adhere to this timetable to ensure you're taking good care of your teeth. If your toothbrush is a Sonicare FlexCare Platinum HX9172, it's the easy snap-on replacement brush you need, so to save some money, consider getting a generic brush 4-pack from Dental Mart. They are also gentle on your gums while effectively removing plaque, and the push-on connector makes them easy to clean.
This 4-pack of Sonicare brushes is suitable for these models:
Sonicare R710/Sonicare R732 Sonicare RS910/Sonicare RS930 Sonicare RS950