Adhesive Strength between Flexible Hydroxyapatite Sheet and Tooth Enamel


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Tooth enamel cannot be reconstructed once it is destroyed immoderately. Hydroxyapatite (HAp) thin sheet can potentially be used for a novel dental biomaterial to repair the enamel. Using a pulsed laser deposition (PLD) method, we have successfully created a flexible HAp sheet of less than a few micrometers in thickness. Due to its flexibility, the HAp sheet is tightly adhered on curved surfaces at the target site. In the present study, we newly developed double-layered sheets composed of HAp film coated with tricalcium phosphate (TCP) thin layer. The HAp/TCP sheet was adhered to the extracted human teeth using a calcium phosphate solution for 3 days. The adhesive strength between the HAp/TCP sheet and tooth enamel was evaluated by quasi-static tensile tests. Moreover, the interface structure between them was observed by a scanning electron microscopy. As a result of the mechanical evaluation, the adhesive strength was greater than approximately 2.5 MPa. The electron microscopic observation revealed that the sheet was partially fused with the enamel. These findings suggest the possibility that enamel defects are repaired using the HAp/TCP sheet for a short duration.



Key Engineering Materials (Volumes 529-530)

Main Theme:

Edited by:

Kunio Ishikawa and Yukihide Iwamoto




E. Yamamoto et al., "Adhesive Strength between Flexible Hydroxyapatite Sheet and Tooth Enamel", Key Engineering Materials, Vols. 529-530, pp. 522-525, 2013

Online since:

November 2012




[1] J.X. Lu, M. Descamps, J. Dejou, G. Koubi, P. Hardouin, J. Lemaitre, J. P. Proust, The biodegradation mechanism of calcium phosphate biomaterials in bone, J. Biomed. Mater. Res. 63 (2002) 408-412.


[2] J.E. Schroeder, R. Mosheiff, Tissue engineering approaches for bone repair: concepts and evidence, Injury 42 (2011) 609-613.


[3] S. Hontsu, T. Matsumoto, J. Ishii, M. Nakamori, H. Tabata, T. Kawai, Electrical properties of hydroxyapatite thin films grown by pulsed laser deposition, Thin Solid Films. 295 (1997) 214-217.


[4] S. Hontsu, M. Nakamori, N. Kato, H. Tabata, J. Ishii, T. Matsumoto, and T. Kawai, Formation of hydroxyapatite thin films on surface-modified polytetrafluoroethylene substrates, Jpn. J. Appl. Phys. 37 part 1 (1998) 1169-1171.


[5] T. Hayami, S. Hontsu, Y. Higuchi, M. Kusunoki, H. Nishikawa, Osteoconduction of a stoichiometric and bovine hydroxyapatite bilayer-coated implant, Clinical Oral Implants Research. 22 (2011) 774-776.


[6] S. Hontsu, M. Nakamori, H. Nishikawa, M. Kusunoki, Characteristics of a humidity sensor using a Na-doped hydroxyapatite thin film, Memories of the Faculty of Biology-Oriented Science and Technology of Kinki University. 26 (2010) 87-91.

[7] H. Nishikawa, R. Hatanaka, M. Kusunoki, T. Hayami, and S. Hontsu, Preparation of freestanding hydroxyapatite membranes excellent biocompatibility and flexibility, Applied Physics Express. 1 (2010) 088001-1-3.


[8] K. Ozeki, T. Yuhta, H. Aoki, I. Nishimura, Y Fukui, Push-out strength of hydroxyapatite coated by sputtering technique in bone, Bio-Med. Mater. Eng. 11 (2001) 63-68.