2013 Fiscal Year Final Research Report

Fabrication of hydroxyapatite block from gypsum block based on (NH4)2HPO4 treatment.

Research Project

Project/Area Number	23592889
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Dental engineering/Regenerative dentistry
Research Institution	Kyushu University
Principal Investigator	SUZUKI Yumiko 九州大学, 歯学研究科(研究院), 研究員 (20432916)
Project Period (FY)	2011 – 2013
Keywords	アパタイト / 骨 / インプラント
Research Abstract	The aim of this study was to evaluate the feasibility of fabricating low-crystalline, porous apatite block using set gypsum as a precursor based on the fact that apatite is thermodynamically more stable than gypsum. The transformation reaction caused a release of sulfate ions due to an ion exchange with phosphate ions, thus leading to a decrease in the pH of the solution. Then, due to decreased pH, dicalcium phosphate anhydrous--which has similar thermodynamic stability at lower pH--was also produced as a by-product. Apatite formed in the present method was low-crystalline, porous B-type carbonate apatite that contained approximately 0.5 wt% CO3, even though no carbonate sources--except carbon dioxide from air--were added to the reaction system. We concluded therefore that this is a useful bone filler fabrication method since B-type carbonate apatite is the biological apatite contained in bone.