Human tooth development having negative effects on human health, including, but not limited to, fetal development. As shown in animal studies which mimic human enamel, the mother’s consumption of products with BPA during pregnancy can lead to the child’s tooth development being obstructed. Those children are shown to be prone to incisor and first molar hypomineralization, a weakened state of the enamel. Additionally, it is most important for mother’s to avoid BPA during pregnancy, but also avoid BPA-use in the child’s products up to five months of age. Anodontia is a complete lack of tooth development, and hypodontia is a lack of some
Smear layer Smear layer The smear layer is a layer of microcrystalline and organic particle debris that is found spread on root canal walls after root canal instrumentation. It was first described in 1975 and much research has been performed since then to evaluate its importance in assisting or preventing the penetration of bacteria into the dentinal tubules. More broadly, it is the organic layer found over all hard tooth surfaces. Early studies of dentinal walls after cavity preparation performed by Brännström and Johnson (1974) showed the presence of a thin layer of debris that was 2 to 5 micrometres thick. In