How do the gums become infected?

Gum disease is caused by plaque, a bacterial film that continuously forms around the teeth. Plaque is responsible for sore, puffy and bleeding gums, bad breath, loose teeth, and teeth that fall out. It is the main reason that people lose their teeth. Until recently, the prospect of losing one's teeth was the main thing a person suffering from gum disease had to worry about. Now, a building body of research has discovered possible links between gum disease and heart disease, heart attack, stroke, respiratory problems, and low birth-weight babies.

Bacterial plaque infects the gums (gingival tissues) when our brushing and flossing does not remove it. Plaque is composed of bacteria that can cause destruction to the gum, connective tissue, and bone that joins our teeth to the jaw. In the healthy mouth, there are hundreds of types of bacteria that naturally live there. Like most bacteria, they have names that defy pronunciation. Most of the inhabitants of our mouth are harmless members of the Streptococcus and Actinomyces species, and are largely gram-positive bacteria. In a patient with gum disease, we see increasing numbers of bacteria, including spirochetes, Bacteroides gingivalis and intermedius, Fusobacterium nucleatum, Eikenella corrodens, Wolinella recta, and others. These bacteria are mainly gram-negative and anaerobic. What this means is that many of the bacteria associated with gum disease can survive without oxygen, which makes sense because they are wreaking havoc with our jawbone deep under the gum-line.

Gum disease causes bone loss because these harmful bacteria in our mouths force our bodies to defend against them. The chain reaction that follows goes something like this:

• The bacteria produce toxins and enzymes under the gum-line, causing a chronic infection.
• This infection causes the immune system to kick in. The body releases chemical substances called cytokines
• The cytokines in turn cause a cascade of reactions within the gum and surrounding tissue.
• One of the substances released is a family of enzymes known as matrix metalloproteinases (MMPs).
• One of the MMPs is collagenase, an enzyme that breaks down gum and bone.
• The loss of gum and bone causes the formation of a periodontal pocket.

The dentist can measure these pockets with a small probe to determine the extent of the disease. These pockets are very bad for your teeth, and if left untreated they eventually cause your affected teeth to fall out.