Calcium Phosphate Cement Containing Resorbable Fibers for Short-Term Reinforcement and Macroporosity

Published

January 1, 2002

Author(s)

Hockin D. Xu, Janet Quinn

Abstract

Calcium phosphate cement (CPC) sets to form hydroxyapatite and has been used in medical and dental procedures. However, the brittleness and low strength of CPC prohibit its use in many stress-bearing locations, unsupported defects, or reconstruction of thin bones. Recent studies incorporated fibers into CPC to improve its strength. In the present study, a novel methodology was used to combine the reinforcement with macroporosity: large-diameter resorbable fibers were incorporated into CPC to provide short-term strength, then dissolved to create macropores suitable for bone ingrowth. Two resorbable fibers with 322 mm diameters were mixed with CPC to a fiber volume fraction of 25 %. The set specimens were immersed in saline at 37 C for 1 d, 7 d, 14 d, 28 d and 56 d, and were then tested in three-point flexure. SEM was used to examine crack-fiber interactions. CPC composite achieved a flexural strength 3 times, and work-of-fracture (toughness) nearly 100 times, greater than unreinforced CPC. The strength and toughness were maintained for 2 to 4 weeks of immersion, depending on fiber dissolution rate. Macropores or channels were observed in CPC composite after fiber dissolution. In conclusion, incorporating large-diameter resorbable fibers can achieve the needed short-term strength and fracture resistance for CPC while tissue regeneration is occurring, while creating macropores suitable for vascular ingrowth when the fibers are dissolved. The reinforcement mechanisms observed were crack bridging and fiber pullout; the mechanical properties of the CPC matrix also affected the composite properties.

Citation

Biomaterials

Volume

23 No. 1

Pub Type

Journals

Keywords

calcium phosphate cement, hydroxyapatite macroporosity, reinforcement, resorbable fiber, strength

Citation

Xu, H. and Quinn, J. (2002), Calcium Phosphate Cement Containing Resorbable Fibers for Short-Term Reinforcement and Macroporosity, Biomaterials (Accessed December 13, 2024)