Periodontal Disease - Did you know that the number one cause of tooth loss is from gum disease? Despite what you might think, people lose teeth more often to gum disease (called periodontal disease) than they lose to tooth decay. In fact, periodontal disease accounts for approximately 80% of tooth loss. Periodontal disease is a cumulative process that is caused by bacteria in plaque and tartar at the gum line. The bacteria cause an inflammatory process that harms bone and gum tissue around the roots of the teeth. This is why it is so important for a dentist to thoroughly assess the gums during a dental examination.