Inorganic bone cements

It has been well known that weak interfaces between the inorganic fillers and the organic matrix reduce the mechanical strength of bone cement [38,40,44,45]. The interfacial adhesion strength can be enhanced by plasma treatment, which is generally due to the improved wettability and possibly to the chemical bonds between the filler and the resin [46,47]. Especially in acrylic bone cement, chemical bonds may have an important role in improving the mechanical strength by the plasma treatment. 

In the short lapse of a few years, the research works on bone regeneration with the aid of bone cements have become more refined in terms of the effects of novel chitosan scaffolds on the cells involved in the healing process. The use of nano-hydroxyapatite as well as other inorganics in conjunction with variously modified chitosans is greatly contributing to the advancement of chitosan composites for bone healing. 

An unsaturated polyester with = 140 °C and T = 20 °C has been prepared from 1,4-CHDM and diethyl fumarate by melt poly-condensation. The polyester was then crosslinked using N-vinyl pyrrolidone in the presence of variable amounts of inorganic fillers. The hydrolytic stability of these composites with different compositions was then examined for their potential use as bioresorbable boned cements (27). 

Cement, dentin, and enamel are bone-like substances. The high proportion of inorganic matter they contain (about 97% in the dental enamel) gives them their characteristic hardness. The organic components of cement, dentin, and enamel mainly consist of collagens and proteoglycans their most important mineral component is apatite, as in bone (see above). 

Ooms, E. M., Wolke, J. G. C., van de Heuvel, R., Jeschke, B., and Jansen, J. A. 2003. Histological evaluation of the hone response to calcium phosphate cement implanted in cortical bone. Biomaterials 24 989-1000. Ooms, E. M., Wolke, J. G. C., van der Waerden, J. P. C. M., and Jansen, J. A. 2002. Trabecular bone response to injectable calcium phosphate (Ca-P) cement. Journal Biomedical Materials Research 61 9-18. Orlovskii, P. V., Komlev, V. S., and Barinov, S. M. 2002. Hydroxyapatite and hydroxyapatite based ceramics. Inorganic Materials 38 1159-72. 

Apatite cement (AC) based on calcium phosphates offer an advantage for being freely moldable aM adaptable to the surface of bone defect. In addition, they have excellent biocompatibility because of their similarity to the inorganic component of the calcified tissue of the body [1,2], The first AC, reported by Prof Moruna and Kanazawa in 1976 was based in a-tricalcirrm phosphate (a-TCP, a-Ca3(P04)2), the cement converted to calcimn deficient HAp (CDHAp, Ca9(P04)s(0H)2) at a temperature below 100°C [3], Setting... 

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