The development of apatite cement that has the enhanced speed of bone replacement

2004 Fiscal Year Final Research Report Summary

• Project/Area Number: 14571897
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Surgical dentistry
• Research Institution: The University of Tokushima
• Principal Investigator: FUJISAWA Kenji The University of Tokushima, Medical and Dental hospital, Assistant Professor, 歯学部附属病院, 講師 (40228979)
• Co-Investigator(Kenkyū-buntansha): MIYAMOTO Youji Akita University, School of Medicine, Associate Professor, 医学部附属病院, 助教授 (20200214) ; ISHIKAWA Kunio The University of Kyushu, Graduate School, Professor, 大学院・歯学研究科, 教授 (90202952) ; NAKANISHI Hiroaki The University of Tokushima, Medical and Dental hospital, Assistant Professor, 医学部・歯学部附属病院, 講師 (00243717) ; KITAOKA Eiichiro The University of Tokushima, Medical and Dental hospital, Research Associate, 医学部・歯学部附属病院, 助手 (60343307)
• Project Period (FY): 2002 – 2004
• Keywords: carbonate calcium / Hydroxyapatite / osteoclast / osteoblast / the resorption of biomaterials

Research Abstract

Firstly, we prepared the best size of carbonate calcium and mixed dicalcium phosphate anhydrate. The obtained powder was mixed into newtral hydrogen phosphate aqueous solution, and was packed into a plastic mould. The disc set after 24 hours was evaluated by means of powder X-ray diffraction. The X-ray diffraction pattern revealed apatitic mineral with poor crystallinity.
Secondly, we evaluated the resorption of the disc by osteoclast. As a result, the set disc was resorbed by osteoclast. Furthermore, when the set disc was immersed into acid solution, we found that the rate of resorption on the set disc by osteoclast was consistent with the rate of acid amount. These results showed that the set disc which contained carbonate calcium, had the ability of faster resorption than conventional apatite cement.
Thirdly, we studied the evaluation of osteoconductivity on the set disc with osteoblast. Briefly, osteoblast was seeded on the set disc and we evaluated the differentiation of osteoblast by RT-PCR methods. The results showed that the set disc promoted the differentiation of osteoblast.
Now we implant the set disc into animal bone to study the histological evaluation. In shorter period, we could not find out the significant difference compared with conventional apatite cement. In longer period, we are studying the significant differences of resorption on the set disc compared with conventional apatite.