“The root of the problem” is a more usual usage, but is just as readily applied (ha get it) as “the root of the solution”, especially when a dental pun can be bonded (puns are swell) to the headline (I can’t think of a way to pun on gumline here).

I found the phrasing really difficult to read and understand, even though I got the pun, so you’re not alone in that.

Root as in seed [crystal], as in nucleation point is what I would surmise.

Dentistry pun? Root as in the root of a tooth?