Periodontitis is inflammation of the gums and supporting structures of the teeth. It is one of the most common human diseases. Periodontitis is caused by certain bacteria (known as periodontal bacteria) and by the local inflammation triggered by those bacteria.The severity and speed of progression of periodontitis depends upon the balance of a number of factors: the number and type of bacteria present, how strong the individual's defense mechanisms are, and the presence or absence of certain risk factors. If the progress of periodontal inflammation is not halted, the supporting structures of the teeth, including the surrounding bone, are destroyed. With careful assessment and treatment, it is usually possible to completely halt the progress of periodontitis. The key to success is to eliminate the bacterial plaque which is triggering the disease process and to establish excellent oral hygiene practices. Thus, this book is written for all individuals, from students to educators, clinicians to researchers, and specialist to generalist.