Hyaline layer of Hopewell-Smith derivative proteins, such as Emdogain, in trying to stimulate reproduction of cementum in periodontal bony defects is based on the presence of enamel matrix-like proteins within the hyaline layer. Hyaline layer of Hopewell-Smith In tooth development, the hyaline layer of Hopewell-Smith is the most peripheral layer of initially unmineralized dentin that forms immediately subjacent to the cementodentinal junction (CDJ). It eventually mineralizes, but not before the rest of the dentin is already mineralized. It is 0.5-0.8 µm thick and contains enamel matrix-like protein as well as the proteins one would expect to find in dentin. It is into this hyaline
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