I bought this months ago and went on to purchase replacement heads, I have not had to replace the head yet as the bristles have stayed quite good, not mooshed down at all. After brushing I rinse my toothbrush very well, then spray the bristles with hydrogen peroxide to sanitize. Stand the brush, bristles up to dry.
I use it twice daily.
I am an adult and have tried multiple Radius adult brushes. I found the adult size head too large to effectively massage my gums, front, back, upper and lower, left, right, front. I also had difficulty with the angled handle. The adult size was just too big for me. I loved the soft bristles, and having the choice of colors, as well as really appreciating the concept of replacing a worn out brush rather than throwing it out. That's when i checked out the "BIG KIDZ" toothbrushes and gave it a try. WOW! Perfect for me! I love it.
BTW: The video offered by Radius on how to correctly brush your teeth, and massage your gums is awesome! And will improve your dental/oral health.