If you are using one of the many powerbrushes on the market, you are likely experiencing a significantly higher level of cleaning than the manual brush owner. I have long been a fan of the powerbrushes, particularly the Sonicare line.
That being said, it’s very important to be mindful of the life of the brush head. They are meant to be replaced regularly. Many of them have color indicators in the bristles. This is the best way to determine if it is, in fact, time to replace the head.
Everyone will use the brush slightly differently and need to replace at differing intervals. If you feel that your brush seems lackluster, it’s probably the brush head needing to be replaced and not the actual brush. Try replacing the head before shelling out for an entirely new brush. Your teeth will thank you!