Medically reviewed by Edmund Khoo, DDS Periodontal disease (gum disease) is a bacterial infection of the gums that affects about 4 in 10 adults over 30 in the United States. It's caused by plaque (a ...

The subject chewed each piece of gum for 4 minutes, producing samples of saliva every 30 seconds, then did a final mouth rinse with clean water, all of which got combined into a single sample.