The Sensitive Pro-Relief toothpaste tube closure specifically... I the paste is fine ( I think) however the closure does have a real problem which actually scares me. I have sensitive teeth and I bought the product... it seemed to work. However after a week I started to get gum irritation, I have never had much of a problem with gums in the past so I just stepped up my dental regimen - no change. There was nothing that seemed to be working. It was only by accident I noticed the inside of the cap had dark yellow-brown deposit forming around the... read full review »