Pattern of caries experience in permanent molars in a 15-year-old African population

Some epidemiologic studies from Africa report higher DMF values in second than in first molars. It is generally accepted that the maturation of dental enamel influences the susceptibility of teeth to caries. The purpose of the present study was to test the hypothesis that DMF values of second molars will be higher than those of first molars if the first molars have reached a high degree of maturation before being exposed to increased cariogenic challenge. The study was carried out in a group of 15-year-old students attending secondary schools in Botswana (n = 287). The results showed that in children who assumingly had had a traditional diet during childhood the DMF values were higher in second molars than in first molars. In children who grew up in a more urbanized setting, the results were opposite. The observed differences were due to differences in caries experience in first molars only. The DMF values of second molars did not vary among the groups. Oral hygiene, sugar consumption and knowledge level at age 15 seemed to have no effect upon the caries pattern studied. It is concluded that the results support the hypothesis tested.