Indices are important tools to measure, quantify and treat periodontitis both in epidemiological and clinical situations and are based on the prevailing understanding of the pathogenesis of periodontal disease. However, there is dearth of literature on collective information of periodontal indices formulated to date. This article collectively describes the evolution and the present concept of formulation of periodontal indices based on the multi-factorial nature of periodontal disease and also provides some direction for future periodontal indices. Periodontal indices have evolved from the simple Russell's index to the current usage of measurement of clinical attachment level in the recording of indices. The use of dichotomous measurements and the Genetic Susceptibility Index are the new additions to the periodontal indices. Nevertheless, an ideal would be an index that will keep pace with the ever changing concept of the pathogenesis of periodontal disease.
© 2011 FDI World Dental Federation.