Scanning Electron Microscopic Observations of Various-Shaped and Sized Enamel Defects in Human Teeth

Abstract

Various-shaped and sized defects of human coronal enamel were illustrated by scanning electron microscopy. Small Tomes' process pits (TPP) and larger focal holes (FH) were usually present in the enamel surfaces. On the other hand, FH-like defects were often scattered in the regions adjacent to large enamel defects. Some TPP contained a smaller punchedout deep pit (POP). In the natural surfaces of hypoplastic enamel, keyhole-shaped prism structures (KHP) were observed. Some KHP also contained a POP . That is, the center of enamel prisms occasionally mineralized later than the other prism regions. Small deep holes, roughly equal to FH in diameter, were relatively rarely observed . In rare cases, large shallow and deep defects were observed, while minor irregular oval or slit-shaped defects with a depth up to 15 μm were scattered in the supracervical zones . In addition, the rows of conic-shaped defects running longitudinally or transversely were found in the supracervical zones . The floors of the large defects showed TPP, KHP, or afibrillar cementum-like structures as well as smooth enamel surfaces. FH and TPP occasionally with a smaller POP , which are usually present along the perikymatas, are formed by the final stage of normal amelogenesis , while the remaining pits and defects must have been caused by some hypoplastic enamel .