Assessment of Dental Caries Increments I. Construction of the R.I.D. Index

¹ University of Oregon Dental School and Reed College, Portland, Oregon

An index is presented for assessing the relative increment of decay in intervals of time. The index is an expression of the ratio of the new carious surfaces to the total surfaces available in a given time interval. Weighting factors are utilized for surfaces changing from caries-free to filled and from missing to carious or filled. Some of the limitations of the index are mentioned.

The R.I.D. index is designed to permit comparisons of rates of dental caries activity of children in primary, mixed, and permanent dentitions or to allow longitudinal assessment of the dental caries rates of the child throughout the period of active growth.