Premium
High early strength calcium phosphate bone cement: Effects of dicalcium phosphate dihydrate and absorbable fibers
Author(s) -
Burguera Elena F.,
Xu Hockin H. K.,
Takagi Shozo,
Chow Laurence C.
Publication year - 2005
Publication title -
journal of biomedical materials research part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.849
H-Index - 150
eISSN - 1552-4965
pISSN - 1549-3296
DOI - 10.1002/jbm.a.30497
Subject(s) - materials science , cement , apatite , scanning electron microscope , bone cement , flexural strength , calcium phosphate cement , composite material , fiber , nuclear chemistry , mineralogy , chemistry
Calcium phosphate cement (CPC) sets in situ to form resorbable hydroxyapatite with chemical and crystallographic similarity to the apatite in human bones, hence it is highly promising for clinical applications. The objective of the present study was to develop a CPC that is fast setting and has high strength in the early stages of implantation. Two approaches were combined to impart high early strength to the cement: the use of dicalcium phosphate dihydrate with a high solubility (which formed the cement CPC D ) instead of anhydrous dicalcium phosphate (which formed the conventional cement CPC A ), and the incorporation of absorbable fibers. A 2 × 8 design was tested with two materials (CPC A and CPC D ) and eight levels of cement reaction time: 15 min, 30 min, 1 h, 1.5 h, 2 h, 4 h, 8 h, and 24 h. An absorbable suture fiber was incorporated into cements at 25% volume fraction. The Gilmore needle method measured a hardening time of 15.8 min for CPC D , five‐fold faster than 81.5 min for CPC A , at a powder:liquid ratio of 3:1. Scanning electron microscopy revealed the formation of nanosized rod‐like hydroxyapatite crystals and platelet crystals in the cements. At 30 min, the flexural strength (mean ± standard deviation; n = 5) was 0 MPa for CPC A (the paste did not set), (4.2 ± 0.3) MPa for CPC D , and (10.7 ± 2.4) MPa for CPC D ‐fiber specimens, significantly different from each other (Tukey's at 0.95). The work of fracture (toughness) was increased by two orders of magnitude for the CPC D ‐fiber cement. The high early strength matched the reported strength for cancellous bone and sintered porous hydroxyapatite implants. The composite strength S c was correlated to the matrix strength S m : S c = 2.16 S m . In summary, substantial early strength was imparted to a moldable, self‐hardening and resorbable hydroxyapatite via two synergistic approaches: dicalcium phosphate dihydrate, and absorbable fibers. The new fast‐setting and strong cement may help prevent catastrophic fracture or disintegration in moderate stress‐bearing bone repairs. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005