Preparation and characterisation of calcium phosphate cement made by poly(acrylic/itaconic) acid

Abstract

In this study, the compressive strength and bioactivity of strong polymeric calcium phosphate cement (PCPC), made by mixing a calcium phosphate powder (a mixture of tetracalcium phosphate and dicalcium phosphate dihydrate) and an aqueous solution of poly(acrylic/itaconic) acid, were investigated. The characteristics of the cement such as phase composition, setting reaction products and microstructure were analysed and compared to those of a control sample made by the same solid phase and water as a liquid. The hard tissue healing capability of PCPC was tested in a rabbit model by radiographical observations of the healing process as well as the cement condition. The results showed that the compressive strength of the set PCPC was y35 MPa before soaking in a simulated body fluid (SBF), which was much higher than that of the control specimen. However, it sharply decreased when the cement was immersed in the SBF. Xray diffraction analysis revealed that tricalcium phosphate was formed in the set PCPC and only a small amount of hydroxyapatite was produced after seven days soaking. In contrast, hydroxyapatite was almost the only phase of the control specimen after the soaking period. Radiography tests showed a cement (PCPC) with an irregular macrostructure after three months implantation, with a decreased radiopacity, and without any periosteal or intercortical callus formation.

The addition of synthesized hydroxyapatite and fluorapatite nanoparticles to a glass-ionomer cement for dental restoration and its effects on mechanical properties

“…Checking with the related card of the pure material, it was exhibited that the synthesized nanoparticles after calcination at 700 °C were formed in almost pure states (ICDD standard, HA: JCPDS No. 09-0432), and all the peaks corresponded to a hexagonal crystal system of HA(42, 43, [61][62][63][64][65]. In all cases, the small size of the particles formed after drying caused the formation of broad peaks in the XRD pattern (66).…”

Development of strong and bioactive calcium phosphate cement as a light-cure organic–inorganic hybrid

“…To select maximum P/L ratio to have a workable paste, cement pastes with various P/L ratios (from 2.0 to 3.0 g/mL) were tested in terms of consistency based on the method described previously [17]. Briefly, the cement paste was pressed between two glassy slabs under compressive pressure of 20 N. The sample was considered workable when no cracks were appeared at the edges of pressed paste.…”

“…In this part of study, the extracts of LCCPCs were prepared in full culture medium according to International Standard Organization (ISO/EN 10993-5) [17] and used for cytotoxicity evaluations. The dissolution extracts of various cements were prepared by adding each LCCPC in powdered form to serum free a-MEM culture medium at a ratio of 200 mg/mL.…”

Current themes in cement research

“…Attempts to increase the inherent strength by e.g. using organic polymer acids as the activating liquid to produce a polymer-modified cement have had limited success so far 59 . Strengthening continues to be a focal research area.…”

“…Since this is easily done in cements by varying the powder/liquid ratio, they are an ideal slow-release, topical delivery mechanism. For example, growth factors can be delivered more effectively and safely by CP cements than injections 61 and two-stage control of the release rate of antibiotics can be achieved via a surface mechanism where release proportional to the square root of time (and thus presumably diffusion controlled), and a CP resorption release mechanism proportional to time 62 .…”