While some bacteria are harmless, the bacteria that cause gum disease are not. This bacteria, thrives in the dark warm environment underneath the gum tissue. There the bacteria form what we now know is a biofilm. If the biofilm is not removed along with the harmful bacteria, the infection will destroy the bone and supporting structures of the teeth. The teeth become loose and are soon lost. More importantly is the correlation between periodontal disease and systemic diseases such as cardiovascular disease, diabetes and rheumatoid arthritis among others.