title: Elucidation of real-time hardening mechanisms of two novel high-strength calcium phosphate bone cements.
abstract: Despite the numerous literature data available in the field of calcium phosphate bone cements, the mechanism and kinetics of their hardening, both of which are of great importance for cements application, in most cases, is unknown. In this work, the mechanism and kinetics of hardening of two novel high-strength calcium phosphate bone cements were studied using the energy dispersive X-ray diffraction technique, which allows rapid collection of the patterns. The phase transformations occurring on the setting and hardening processes were monitored in situ. Containing minimal quantity of components, whose mixing leads to the formation of cements with pH close to neutral, the cements under study are simple in handling. The main component of both formulations is tetracalcium phosphate. In both cements, the effect of the addition of high- and low-molecular weight chitosan on phase development and kinetics was investigated in detail. One of the cements has the compressive strength of about 70 MPa, whereas the strength of the other, containing Ca(3)Al(2)O(6), is much higher, about 100 MPa. This latter cement could be regarded as an alternative to the common low-strength bioresorbable brushite cements.
authors.affiliation: Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences, Moscow 119991, Russia.
authors.forename: Valery V
authors.initials: VV
authors.lastname: Smirnov
authors.forename: Julietta V
authors.initials: JV
authors.lastname: Rau
authors.forename: Amanda
authors.initials: A
authors.lastname: Generosi
authors.forename: Valerio Rossi
authors.initials: VR
authors.lastname: Albertini
authors.forename: Daniela
authors.initials: D
authors.lastname: Ferro
authors.forename: Sergey M
authors.initials: SM
authors.lastname: Barinov
mesh_terms: D001843:Bone Cements / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry; D019245:Compressive Strength; D003460:Crystallization; D006244:Hardness; D006245:Hardness Tests; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008970:Molecular Weight; D033362:Powder Diffraction; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D001843:Bone Cements; D002130:Calcium Phosphates; D048271:Chitosan; C494366:calcium phosphate, dibasic, dihydrate