Ultrathin Amorphous Calcium Phosphate Freestanding Sheet for Dentin Tubule Sealing

Novel dentin tubule sealing technique using ultrathin Amorphous Calcium Phosphate (ACP) freestanding sheet was developed. The sheets were prepared by pulsed laser deposition technique and separated from quarts substrate by dissolving photoresist as sacrifice layer. Sheets were pasted on dentin of extracted human teeth by using calcium phosphate aqueous solution. The sheets kept wetted by artificial saliva for a few days. After drying specimens, the bonding strength between the sheets and dentin were evaluated by quasi-tensile tests. The bonding strengths between the film and dentin were enough to seal dentin tubules. After tensile test, the specimens were embedded in epoxy resin and polished for investigation of bonding boundary nature. The presence of a few microns thick bonding layer between the film and dentin was shown clearly by cross-sectional electron microgram. These results suggest that the dentin tubules may be sealed by calcium phosphate sheet without organic materials.