Research in Imaging and Health Technologies Osteoconduction, Osteogenicity, Osteoinduction, what are the fundamental properties for a smart bone substitutes

Abstract Resorbable syntheticbonegraftmaterialsaremainlycalciumphosphates.Thesematerialsdifferinchemicalcompositionandphysicalproperties,particularly in regards of osteoconduction, osteogenic and/or osteoinductive properties. Several scaffolds are characterized and compared. Resultsfrom preclinical and clinical studies are selected. Osteoconductive properties have been largely described but “osteoinductive” properties havebeen less explored and documented. The purpose of this paper will be to present series of data demonstrating the differences in scaffolds for boneregeneration and to explain how dissolution and, biological precipitation into the micropores occur simultaneously with osteoid and bone formationafter implantation in bony and non-bony sites and support the osteogenic/osteoinductive properties.© 2013 Published by Elsevier Masson SAS. 1. Introduction Bone graft materials (available as alternatives to autoge-neous bone) include: resorbable and non-resorbable polymers;special glass ceramics described as bioactive glasses; calciumphosphates (calciumhydroxyapatite,HA;tricalciumphosphate,TCP; and biphasic calcium phosphate, BCP); and materialsderived from natural sources (e.g., bovine or human bone orcorals). These materials differ in chemical composition andphysical properties from each other and from bone, particularlyin regards of osteoconduction, osteogenic and osteoinductiveproperties. Propertiesofcalciumphosphatebioceramicsrelatingto theirs medical applications, include: macroporosity, micro-porosity, compressive strength, bioreactivity (associated withformation of carbonated hydroxyapatite on ceramic surfacesin vitroandinvivo),dissolution,andosteoconductivity.Osteoin-duction, osteoconduction are interrelated, but not identicalphenomena. Osteoinduction is part of normal bone healing andis responsible for the majority of newly formed bone, e.g. after afracture or the insertion of an implant. The implant itself may be