Because periodontal disease is an infection, it may cause bad breath. Elimination of the infection and good daily brushing and flossing is needed to stop this problem.
However, it is interesting to note that the vast majority of people with chronic bad breath have healthy gums. We now know that almost all halitosis (bad breath) is caused by bacteria on the back of the tongue breaking down mouth proteins into odor causing compounds.
Bacteria scraped from back of tongue
Vigorous tongue scraping will help with bad breath, but for some people this is still not enough. Specialized testing and treatment is available for those patients, and complete elimination of the problem can be expected.
Halimeter, a machine that tests for odor-causing gases in your breath