[Measurement of epidemiological facts in dentistry]

Recent epidemiological investigations about caries report about phenomenons like "caries increase" or "caries decline". This kind of observation bases on prevalence-studies. But describing such phenomenons does not give the opportunity to explain the observations. For that purpose the modern methodology of epidemiology should be used. Despite of the fact that epidemiology differs exactly between incident and prevalent cases, the use of incidence studies seems to be extremely seldom in stomatology. This paper discusses the problems, which occur in incidence-studies about caries and especially in cohort-studies. The authors show the difficulties to adopt terms like incidence density and cumulative incidence to studies about caries. A proposal is given in order to adopt the modern methodology of epidemiology to the special problem of caries.