Hello!
I've found this article that claims gums can be made to grow back using a product called genigel.
http://www.dailymail.co.uk/health/article-67661/Get-smile-back.html
"Genigel, the new treatment, contains hyaluronic acid - a sub-stance found in the connective tissues of the body. When applied to gums, it provides a sticky film in which new cells and blood vessels can grow."
"A week later, the teeth began to firm up. A month later, I could chew on them. The gel has actually made my gums grow back, which is something no amount of brushing or anti-bacterial mouthwashes could ever do."
Probably, these claims are not true otherwise dentists wouldn't still be saying that gums can't be grown back, but I thought I'd make sure and ask you whether you know of any research done proving or disproving these claims.