I picked up a Aqua Fresh Gel Flex about 3 years ago and have been using the same one ever since (no exaggeration), but only because all of the other brushes I had purchased to replace it in that amount of time were like wire brushes, pushing my gum line higher. I have literally tossed out about 20 different brushes in that amount of time that could not cut it, with a total cost of over $100. The Gel Flex is a truly soft brush, making it easy to give a little pressure to get between teeth on the side. It is the only brush I have used in my entire life that is actually soft. I do not know why I am just getting around to looking these up and ordering them online, should have done this years ago. You know you got a good brush when you use it till the bristles start falling out because nothing can replace it. I went for the 6 Pack, cost was $25 shipped. I would have paid $25 for 1.