Injectable Calcium Phosphate Cement: Effects of Powder-to-Liquid Ratio and Needle Size

Published

July 16, 2007

Author(s)

Elena F. Burguera, Hockin D. Xu, Limin Sun

Abstract

Calcium phosphate cement (CPC) sets in-situ with intimate contact with neighboring bone and forms apatite with excellent osteoconductivity and bone-replacement capability. The objectives of the present study were: to formulate an injectable tetracalcium phosphate (TTCP)-dicalcium phosphate (DCPD) cement (referred to as CPCD); and to investigate the effects of cement powder/liquid ratio and needle size on injectability. Varying the needle size from 10 gauge (inner diameter = 2.69 mm) to 25 gauge (0.26 mm) had a significant effect on injection. The injection force (mean sd; n = 4) significantly increased from (8 2) N using the 10-gauge needle to (144 17) N using the 21-gauge needle (Tukey s at p of 0.05). Varying the powder/liquid mass ratio from 2 to 4 also had a significant effect on injection. Using the 10-gauge needle, the mass percentage of paste extruded was (95 4) % at powder/liquid of 3; it decreased to (70 12) % at powder/liquid of 3.5 (p < 0.05). A relationship was established between the injection force, F, and the needle lumen cross-sectional area, A, for CPCD: F = 5.0 + 38.7 / A0.8. The flexural strength (mean sd; n = 5) increased from (5.3 0.8) MPa at powder/liquid of 2 to (11.0 0.8) MPa at powder/liquid of 3.5 (p < 0.05). Meanwhile, the pore volume fraction decreased from 62.4 % to 47.9 %. A relationship was established between the flexural strength, S, and the porosity, P: S = 47.7(1 P)2.3. The strength of the injectable CPCD matched/exceeded the reported strengths of sintered porous hydroxyapatite implants that required machining. In summary, the effects of needle size and powder/liquid ratio on the injectability of CPCD were systematically investigated for the first time. The injectable calcium phosphate cement may be useful in filling defects with limited accessibility such as periodontal repair and tooth root canal fillings, and in minimally-invasive techniques such as percutaneous vertebroplasty to fill the lesions and to strengthen the osteoporotic bone.

Citation

Biomaterials

Volume

84B

Pub Type

Journals

Download Paper

Local Download

Keywords

bone repari, calcium phosphate cement, injectability, nano apatite strength, Dentistry

Citation

Burguera, E. , Xu, H. and Sun, L. (2007), Injectable Calcium Phosphate Cement: Effects of Powder-to-Liquid Ratio and Needle Size, Biomaterials, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=852731 (Accessed July 26, 2024)