You could be one of 50% of Americans who have periodontal disease, the major cause of tooth loss in adults. Periodontal disease is an infection of the gums and surrounding bone structure around the teeth. It starts off as plaque, an opaque film which eventually hardens, forming tartar or calculus. Calculus deposits harbor bacteria which infect the gums. In early stages, this is called gingivitis. Symptoms include red, swollen gums that bleed when you brush your teeth. It also may cause bad breath and an unpleasant taste in their mouth. Left untreated, gingivitis becomes periodontitis, a much more serious form of the disease where periodontal pockets are formed, separating teeth from the gums and supporting bone structure. Without treatment, infection progresses and the pockets deepen, resulting in tooth loss.