Some people have issues with the gums receding from around the teeth, I believe. For me, it's been issues with old fillings - I've had two broken that have taken away some of the tooth with them. Dentist has said that all looks okay now but I may be grinding my teeth in my sleep (sleep? what sleep?) putting extra pressure on them so I am going to look at getting a guard made up. The other thing I have noticed is that sensitivity has increased (I used to have problems with that when I was younger) but the sensitive toothpaste seems to be sorting that.