I have read on the net about the possibility of transmitting the bacteria
in people with periodonitis between spouses. My girlfriend has had the
disease for several years and has always had proper care. Now I was
wondering is there a possibility I could get this condition. My teeth are
fine except for some cavaties and a root canal. Any experience anyone has
would be greatly appreciated.

Periodontal disease is RARELY an infectious disease … just look to
the epidemiology.

You are born without the periodontal pathogens in your mouth. You acquire
those bugs via bacterial transfer from someone else. However, you don’t get
the disease unless you are susceptible.