In Bantu and European races, in South Africa, there is no consistent relationship between hardness or perfection of teeth, nor state of mouth hygiene, and activity of caries. Sugar is the most important factor in causing caries.
In Bantu living according to primitive tribal conditions, there is very little caries, and the percentage of affected teeth in each carious dentition is exceedingly low. Bantu living under civilized conditions frequently exhibit caries but, as in primitive Bantu, the percentage of affected teeth is low. Increase in caries in civilized Bantu is associated with consumption of sugar. Among South African children of European descent, caries is an extremely prevalent disease. In South Africa the amount of sunlight is sufficient to produce the vitamin necessary for growth of bones and teeth. Therefore it is exceedingly improbable that, in South Africa, the prevalence of caries is due to lack of vitamin D. Among South African children in public government schools, high incidence of caries appears to be associated with excessive consumption of sugar and carbohydrates generally.
References: Brit. Den. J., 1931; S. Afr. Med. J., 1932 ; The teeth, the bony palate and the mandible in Bantu races of South Africa, 1931 (John Bale, Sons and Danielsson, London).