It has been suggested that the concentric spherical deposits and laminate lines in decalcified sections of human dentin under silver-staining are formed by periodic calcification. However, such observations have been made after decalcification. In Japan, these structures are referred to as calcified striations or dentin ripples.
In this scanning electron microscope study, a regular alternation of dense and loose laminate deposits of collagen fibers with a periodicity of about 1μ m was found on fractured planes ofdentin that had been etched with EDTA after treatment with NaOCl. Spherical and linear laminate structures may be formed by mineral deposition, similar to staining by silver particles, in parallel with the periodicdeposition of collagen fibers observed in this study. However, since these periodic changes were not observed inbackscattered electron images, they may be very mild.