Prevalence of black stain and associated risk factors in preschool Spanish children

Background In pediatric clinical practice, it is common to be asked about the presence of black stains on teeth in children and teenagers. According to controversial etiology, it is known to be related to a low rate of caries. The aim of this study was to determine the prevalence of black stain and associated risk factors in Spanish preschool children. Methods A total of 3272 children aged 6 years old (3058 non-emigrant and 214 immigrant children) living in Oviedo (Spain), were enrolled in the present study. Results The prevalence of black stain was 3.1% in the whole group. The index of primary decayed, missing, and filled teeth (dmft index) associated with black stain was 0.35 ± 1.123. A statistical association between black stain and the consumption of iron supplements was noted. Conclusions The regular consumption of foods rich in iron and the use of iron supplements during pregnancy and early childhood, could favor the development of chromogenic microbiota. The prevalence of black stain did not differ significantly between non-emigrant and immigrant children in Spain.