This paper discusses the influence of changes in population characteristics on root caries and re-examines the epidemiology of the disease. The difficulties in interpreting the available data on the prevalence and incidence are high-lighted and the last decade of studies are summarized in table form. The effect on clinical data of dentists' treatment decisions are addressed and demonstrated using data from a longitudinal study involving 24 dental practitioners in Manchester, UK. These dentists recruited and collected clinical information on a group of their regularly attending dentate adult patients. For the over 55 year olds, the results indicate that a conventional epidemiological study would have underestimated the number of surfaces filled for caries by 50%. The paper concludes by suggesting that consideration should be given to novel ways of collecting data so that more information is available on the etiology, prediction and management of the disease.