Using universal patterns of caries for planning and evaluating dental care.

There are universal patterns of caries, in terms of prevalence, incidence, frequency distribution and rates of progression, in permanent teeth that can be considered working rules that can be applied when planning dental care. The universal patterns are: (1) caries levels follow trend lines; therefore, knowing the caries level at one age can be used to predict the levels at later ages in that cohort by looking at the trend line for that cohort; (2) the distribution of dental caries of a population exhibits the following characteristics: as the mean DMFT increases, the percentage of caries-free individuals falls and the caries distribution widens; this changing relationship between the mean DMFT and prevalence is not limited to a subgroup of the population who already have had some caries experience; (3) there is a specific mathematical relationship between the mean DMFT and mean DMFS; (4) there is a hierarchy of caries susceptibility by tooth type and sites on teeth; for a given DMFT or DMFS, there is a specific intra-oral pattern of caries by tooth type; (5) changes in mean DMFT scores for individuals and groups are not linear, but 'stepped'; there are groupings of teeth and tooth sites that may have similar 'resistance' to caries; (6) as the mean DMFT declines, the posteruptive time for initiation of caries increases and the progression rate of caries through enamel decreases. This is true regardless of the presence of fluoride. Any improvement in dental health will cause this effect.