I wish I could give curaprox a dozen stars more, I really cannot tell you how much I love these brushes! I work in dentistry so I get to go to a lot of trade shows. I got given a few brushes as a free sample and gave them a try. Seriously I will never use another brand of brush. Made from 'curen' rather than standard nylon bristles they harbour less bacteria, hold less water and come in over 30 colour combinations and seasonal patterns..! The number on the brush indicates how many bristles the brush has and come in an ultra soft and soft range which are roughly the same as a standard medium brush.