IN A REVIEW of the basic considerations of dental caries, Rosebury distinguished between two varieties of the disease.1The first and distinctly more common type attacks the pits and fissures of the crown or the neighborhood of points of contact of approximating teeth. This type predominates in the teeth of children and young persons. The second and less common variety is found principally in the teeth of adults and appears in the gingival area of the crown or in exposed roots. Because the first variety is by far the more prevalent, dental caries is regarded as predominantly a disease of children and young persons, an observation reported many years ago by G. V. Black.2The highest incidence of caries is noted usually during the period of eruption of the teeth. This is particularly true during the transition from deciduous to permanent dentition, as both dentitions are affected during