Review on current limits and potentialities of technologies for biomedical ceramic scaffolds production

Abstract

Osseointegration is defined by a stable and functional union between bone and a surface of a material. This phenomenon is influenced by the geometric and surface characteristics of the part where the bone cells will attach. A wide variety of studies proves that ceramic materials are strong competitors against conventional metals in the scope of bone tissue engineering. Ceramic scaffolds, porous structures that allow bone ingrowth, have been studied to enhance the osseointegration phenomenon. Geometric and dimensional parameters of the scaffold have influence in its performance as mechanical and structural supporter of bone growth. However, these parameters are conditioned by the manufacturing process by which these scaffolds are obtained. Several studies focusing on the production process of ceramic scaffolds have been developed, using 3D printing, stereolithography, selective laser sintering, green machining, robocasting, and others. The main purpose of this work is to evaluate and compare the different manufacturing processes by which ceramic scaffolds can be produced. This comparison addresses scaffold parameters like pore size, pore shape, porosity percentage, roughness, and so forth. Additionally, the different materials used in different manufacturing processes are also mentioned and discussed given its influence on a successful osseointegration while simultaneously displaying adequate mechanical properties. After making a screening on the available ceramic scaffolds manufacturing processes, several examples are presented, proving the potential of each of these manufacturing process for a given scaffold geometry.

Microarchitecture of titanium cylinders obtained by additive manufacturing does not influence osseointegration in the sheep

“…Both implants exhibited interconnected porosity that promotes osseointegration and differed only in their microarchitecture. Microarchitecture has been reported to be a determining factor in the bone tissue response leading to osseointegration [ 14 , 55 ]. Bone cells are known to have varying affinities with surfaces with different topographic geometries [ 56 , 57 ].…”

“…Implants with trabecular microarchitecture were prepared using bovine trabecular bone as a template in additive manufacturing. Our hypothesis was that such a scaffold mimicking bone microarchitecture would promote osseointegration more than a purely geometric microarchitecture [ 55 ]. However, the cylinder microarchitecture did not influence osseointegration because the amount of bone (BV/TV) and the BS/TitS were never different at any time.…”

Bioactive Ceramic Scaffolds for Bone Tissue Engineering by Powder Bed Selective Laser Processing: A Review

“…), and growth factor attachment [ 58 , 59 , 60 ]. Porosity is also a rather important parameter in osteoconduction [ 61 ]. It has been proven that the fine pore-associated hypoxic conditions can stimulate osteochondral formation before osteogenesis.…”

Clinical Applications of Cell-Scaffold Constructs for Bone Regeneration Therapy

“…Although the composition of HA is similar to native bone, β-TCP rapidly resorbs compared to HA and becomes replaced with new bone tissue, making it more beneficial than HA as a scaffolding material. However, β-TCP also has unfavorable mechanical properties due to its poor fatigue resistance and brittleness, and these characteristics limit its application as a loadbearing biomaterial [52]. Among the calcium phosphate ceramics, biphasic calcium phosphate (BCP), which comprises different concentrations of stable phase HA and the more soluble phase β-TCP, have presented significant advantages.…”