"GUM Expanding Floss is the only kind I use ever since my dentist gave me a sample. I have tight and uneven spaces that used to break and shred regular floss. That left me with bits of floss stuck painfully between teeth, almost impossible to get out. GUM expanding floss is woven so that it gets through tight spaces, but it is still expands wide enough to do a good job cleaning in the wider places. I like it so much that I order it on line by the dozens because it is not carried by our local stores. I swear by it and my wife loves it to. We have it in our bathroom, on our nightstand, by the TV, in our cars, in our desks at work!"