Why are my gums itchy when i floss between my teeth?

When I floss, the floss goes up in between my teeth and gums?

• It just recently started doing this, my dentist says I have VERY good teeth, but I need to floss because I may get cavities in my front teeth, so naturally I start to floss, but this morning, while i was brushing my teeth, I felt a sharp pain when I brushed my two front top teeth, so I brushed really light around there and when I went to floss, I noticed it was red, so I stuck the floss up there to see if there was a gap, and it went half way up my tooth where my gum is suppose to be, but it's not noticeable.... What could it be? How can i solve this?...

• Answer:

  That's EXACTLY what's supposed to happen! Floss is designed to get debris out of those ridges between your teeth and gums that your toothbrush can't reach. Those "pockets" in your gums are great hiding places for food, and when food gets in there it can combine with your saliva and be converted into acid, which causes cavities. That's why dental floss was invented. When you floss, you pull the floss against your tooth but you work it slowly and gently up the gumline so that it looks like the floss is going "into" your gums. If there is any food matter stuck in that area the floss will grab it and pull it out.