Measurement of Howship's resorption lacunae by a scanning probe microscope system

We have developed a novel ultrastructural assay system for osteoclastic resorptive function. After osteoclasts had been co-cultured on dentine slices for 48 hr, the slices were fixed with glutaraldehyde and examined by means of backscattered electron, scanning electron, and scanning probe microscopies. Backscattered electron images showed areas of low mineralization on dentine surfaces, which, by superimposition of concave-convex images, corresponded to resorption lacunae. The measurement of such resorption lacunae by scanning probe microscopy revealed 3-dimensional topography and their exact depths and volumes. Analysis based on this system provides reliable qualitative and quantitative assessment of osteoclastic resorption.