Dental caries prevalence in seven soil areas of New Zealand

Abstract

In a survey of 3555 children aged 5–16 yr in New Zealand, small but highly significant differences in dental caries prevalence were found between groups living in certain soil areas. Caries prevalence was highest in an area containing podzolized yellow-brown earths, gley podzols and wet yellow-brown sands, all relatively strongly-leached soils. A low prevalence of caries occurred in areas containing yellow-brown pumice soils and dry yellow-brown sands, both relatively weakly-leached soils. These findings agree closely with those of previous investigations. However, no relationship between the consumption of locally-grown vegetables or source of water supply and caries could be established within the high or low-caries areas, suggesting that local soil factors are probably not involved in the production of the geographic variations.