Our n-Ha nanoparticles are nanorods having lengths of 20-80 nm (typically 50-60 nm) and widths of 10-15 nm.
This is significantly much smaller than the dentine tubules that typically have 1-2 microns diameter (so, considering an averaged size of 50 nm) we have particles about 40x smaller than the dentine tubules.
If you use micro-hydroxyapatite (as some brands have), then typically the smaller mean particle size of micro-HA you find in the market has at least 5 or 10 microns, which are 5 to 10 times larger than the dentine tubules and will not occlude effectively these to prevent the teeth hypersensitivity.