The histology of sclerotic human root dentine.

Studies by optical microscopy, microradiography and SEM suggested that sclerosis is the result of occlusion of the dentinal tubules by a mineral substance with a refractive index similar to that of the rest of the dentine. Translucence appeared before the majority of the tubules were completely occluded. The deposition of the occluding mineral took place initially in individual tubules or in groups of tubules. The occluding material and the peritubular dentine were almost indistinguishable under SEM. Both were smooth and densely mineralized. The process of deposition of occluding mineral appeared to be more like that of in-vitro mineralization and thus different from that of peritubular dentine.