Jenni, I use duraphat 5000 which I get on prescription. It is a very high concentrated flouride toothpaste my dentist recommended it. You can use it as a normal toothpaste and at night smear a tiny bit over gums and teeth so the flouride is absorbed during the night. I also use a flouride mouthwash every day also on prescription. Even after all this care I have noticed my gums are receeding and are really sensitive. Fortunately by best friend is a dentist!
There is also duraphat 2000 which is not as strong but your gp might prescribe it easier for you.