The diagnosis of active phases of periodontal disease and the identification of patients at risk for active disease, represents a challenge for both researchers and clinicians. A rapid and simple diagnostic test that can provide a reliable evaluation of periodontal disease and identify patients at risk for active disease would be of immense value to both the clinicians as well as the patients. Enzymes in saliva hold the greatest promise as indicators of active periodontal disease. Through this book, the authors make a sincere attempt to provide a valuable insight into the use of Salivary peroxidase enzyme as a biomarker for chronic form of periodontal disease.