The traditional diagnostic methods as well as indices based on their results cannot detect the presence of active periodontal destruction nor do they have predictive value. These are only reliable to know the retrospective diagnosis of attachment loss. The recent research in periodontal diagnosis is aimed at identification of disease process that if allowed to proceed unaltered, will result in future breakdown. Recent immunocytochemically based approach has offered a new avenue in periodontal diagnostic research. The availability of complementary information on pathologically altered tissues has provided new diagnostic products to evaluate patient periodontal status as chair side diagnostic tools. This book aims at providing ample source of information and throwing stress on various advancements in Periodontal Diagnosis.