The precursor to periodontal disease is often gingivitis, an infection characterized by red, swollen gums that bleed easily.
When the bacteria causing gingivitis travel and infect the surrounding bone, the
condition is referred to as periodontal disease. This infection destroys the bone
that holds teeth in place. Gingivitis is reversible, however periodontal disease
is not, and if not stopped can lead to the loss of otherwise healthy teeth. Think
of it as a tree on a riverbank that has had all of the soil washed away from its
roots causing the tree to fall . . . the tree itself was healthy, but its support
was taken away and the tree is lost nonetheless.