Since the early 1970s it has been reported that the prevalence of caries and the rate of caries attack has diminished. The net result is fewer persons develop new lesions and longer periods of time are needed before the carious process results in cavitation. A consequence of this development is that longitudinal caries studies are expensive due to larger numbers of participants needed and/or longer study periods required to demonstrate differences in caries changes among study groups. Concurrently, various improvements in caries detection using high technological methods are also under development. These factors have motivated researchers to pursue new methods of scoring and recording dental caries. Two modifications of the DMFS scoring system were investigated. The first involves scoring dental caries at two levels: an unspecified measure of non- cavitated lesions and the usual criteria for scoring cavitated lesions. The second involves scoring the surface area of existing restorations. We incorporate two levels in this study to illustrate the point (less than 1/2 of the surface restored versus more than 1/2 of the surface restored). Two definitions of caries change are considered. The first addresses the initiation of new lesions, scoring all changes observed consistent with new lesions occurring. The second deals with progression and incorporated changes indicative of caries progression, rather than initiation. Also defined is an assessment of total change in caries status, which incorporates both the initiation and progression of caries lesions. The frequencies of transition from F to D or crowned (C) to D are now included where as the usual DMF increment only used those for S to D, S to F and S to M. The modified indices also used changes between the two levels of disease and those between the two sizes of restorations.
