Human cellular cementum was examined by scanning electron microscopy to elu
cidate the manner of the alternate lamellar pattern forming the cellular ce
mentum. Specimens were demineralized, trimmed with a freezing microtome, an
d treated by NaOH-maceration. This procedure was chosen to avoid artifacts
in the fibril arrangement, and to study the fibrous architecture in detail.
For comparison, non-demineralized, polished and HCl-etched specimens were
also prepared. In the NaOH-macerated specimens, the lamellar pattern of the
cellular cementum conformed to the twisted plywood principle of bone lamel
lation with a periodic rotation of matrix fibrils resulting in an alternati
ng lamellar pattern. In contrast, matrix fibrils were irregularly arranged
without indication of rotation of matrix fibrils in the polished and etched
specimens. Our results suggest that polishing and etching procedures cause
damage to fibrils and fibril arrangement.