IADR Abstract Archives

The Development of a New Hydroxyapatite-Ionomer Cement

Objectives:Conventional glass-ionomer cement (GIC) has favorable clinical properties such as chemical bond to tooth structure and fluorine release, but its mechanical strength is inadequate. Our research then focused on reinforcing GIC by adding hydroxyapatite (HAp). This current study aimed to improve the mechanical strength by adding different types of HAp and to investigate the underlying reaction mechanism by analyzing their physical and chemical characteristics.

Methods:Conventional GIC (FujiIX GP®) was used as the control group. Four different types of HAp (HAp200,HAp100,HAp100f,Nano HAp) was added at 8 mass% into the GIC powder for the experimental group. The characteristics of the experimental powder were examined by SEM observation, determination of their particle size distribution, compressive strength and surface area/pore distribution. The mechanical characteristics of the cement were examined by three point flexural bending tests. The qualitative analysis of the cement's elemental constitution was done by using XPS.

Results:The particle mean sizes were: Nano HAp:3.4mm; HAp100:11.4 mm; HAp200:13.6 mm and HAp100 :236.3 mm. The particle compressive strength of HAp was lower than IX powder. For the surface area and pore distribution, HAp100 and HAp100f were 10-15 times larger than HAp200. Flexural strength has increased in all HAp-added groups. Specially, Nano HAp and HAp100f group showed significant increase compared to control after 24 hours. XPS analysis showed P and Ca in the matrix of HAp-added group. A new hydroxyapatite-ionomer cement with improved strength was developed by adding highly reactive HAp into conventional GIC.

Conclusion:This study suggested that the new hydroxyapatite-ionomer cement matrix was reinforced by the availability of Ca and P ions from the partial dissolution of HAp and the chemical bonding of the matrix to HAp.


World Congress on Preventive Dentistry
2009 World Congress on Preventive Dentistry (Phuket, Thailand)
Phuket, Thailand
2009
88
Posters
  • Yamamoto, Aimi  ( Tokushima University, Tokushima City, N/A, Japan )
  • Arita, K.  ( Tokushima University, Tokushima City, N/A, Japan )
  • Lucas, M.  ( Tokushima University, Tokushima City, N/A, Japan )
  • Shinonaga, Y.  ( Tokushima University, Tokushima City, N/A, Japan )
  • Harada, K.  ( Tokushima University, Tokushima City, N/A, Japan )
  • Abe, Y.  ( Tokushima University, Tokushima City, N/A, Japan )
    • Poster Session
    Other WCPD Topics I
    09/09/2009