Prospective of Calcium Phosphate Cements for Bone Regeneration: Physicochemical, Mechanical and Biological Properties

In the early 1980s, scientists at the American Dental Association Le Geros et al. [1] and Brown & Chow [2-5] first explored the possibility of generating a monolithic calcium orthophosphate ceramic at ambient or body temperature via a cementation reaction among one or more component of calcium orthophosphate precursors. Presently this type of materials is referred to as calcium phosphate cements (CPC) and the discovery of self-setting CPC was a significant achievement in the field of bioceramics for bone regeneration, since it’s self-setting nature opened up the door for minimally invasive surgical techniques as compared to classical surgical methods [6]. The aim of biomimetic CPC is to temporarily play the role of artificial bone with minimal interference on bone functions and properties until a new bone has been grown in its place. Apart from excellent biological behaviour exhibited by CPC, its injectability, hardenability in vivo at body temperature [7,8], mouldability and adaptation to the surrounding bone even for irregularly shaped cavities, represent its unique advantage over other bioceramics, which are difficult to machine and shape [9]. After a comprehensive mechanical characterization for both hydroxyapatite and brushite forming CPC, Charrière et al. [10] found that hydroxyapatite cements have the potential to be structural biomaterials while brushite cements are suitable as bone fillers. Typical application of CPCs are treatment of maxillofacial defects or deformities [6] or the repair of craniofacial defects [11], with the possibility of applying it in moderately load-bearing defects, such as in vertebroplasty or kyphoplasty [12-14].