“…With the decrease of caries activity in many populations [Steiner and Marthaler, 1980;Anderson, 1980;Palmer, 1980;Truin et al, 1981;Kalsbeek, 1981] (table I, II). the question may be raised, whether it is still The percentages reduction in def surfaces in 1978 compared to 1969 are given at the bottom of the table [Plasschaert el at., 1974[Plasschaert el at., , 1977Truine tab, 1981).…”