TABLE 3.

Representative studies on 3D bioprinting for dental, oral, and craniofacial-related regeneration from 2016 to 2020.

Bioink	Bioprinting method	Tissue types	Cells/growth factors encapsulated	Key outcomes	Illustration
GelMA	Microextrusion-based	Periodontal complex	PDLCs	The optimized printing conditions supported a high level of PDLCs viability and facilitated cellular proliferation within the construct over 14 days.	Raveendran et al., 2019
GelMA	Microextrusion-based	Pulp-dentin complex	hDPSCs + BMP-mimetic peptide	BMP-GelMA bioink formulation provided proper printability and dental specific microenvironment to support hDPSCs high viability, proliferation, and differentiation.	Park J. H. et al., 2020
Dentin-derived ECM + Alginate	Extrusion-based	Pulp-dentin complex	Odontoblast-like cell line (OD21) + acid-soluble dentin molecules	Dentin-derived ECM hybrid cell-laden hydrogel bioink showed high printability and cell survival. This hybrid hydrogel embedded with acid-soluble dentin molecules can enhance odontogenic differentiation.	Athirasala et al., 2018
Fibrinogen + Gelatin + Hyaluronic acid + Glycerol	Custom-made syringe bioprinting	Whole tooth	hDPSCs	A dentin pulp complex with patient-specific shape was successfully produced by co-printing the bio-inks with polycaprolactone. After culturing for 15 days, localized differentiation of hDPSCs in the outer region of the construct was achieved with localized mineralization.	Han et al., 2019
ECM bioink (2% octapeptide) + AMP	Microvalve bioprinting	Craniomaxillofacial bone tissue	hDPSCs	The cell-laden bioprinted constructs modified with AMP exhibited a high level of mineralization and osteogenic gene expression in vitro and the ECM/1.0AMP composition displayed excellent bone regeneration capability in vivo.	Dubey et al., 2020
Gelatin-alginate + cellulose nanofibrils + bioactive glass	Extrusion-based	Bone	(i) Human osteoblast-like cells (Saos-2). (ii) hBMSCs	The addition of bioactive glass and cellulose nanofibrils to gelatin–alginate system enhanced their printability and osteogenic activity but resulted in the death of Saos-2 cells due to increased viscosity.	Ojansivu et al., 2019
GelMA + silicate nanoplatelets	Extrusion-based direct-writing bioprinting	Bone	HUVECs + hBMSCs + VEGF	Two GelMA hydrogels containing different concentrations of VEGF were optimized and bioprinted into well-defined 3D architectures, which resulted in the formation of a perfusable lumen, maturation of vascular vessels, and induced osteogenic differentiation.	Byambaa et al., 2017
Agarose + collagen I	Inkjet	Bone	hBMSCs	Increased solids concentrations of collagen in the 3D-bioprinted hydrogel blend enhanced cell spreading, that ultimately contribute to enhanced and directed MSC osteogenic differentiation.	Duarte Campos et al., 2016

GelMA, gelatin methacryloyl; PDLCs, periodontal ligament cells; hDPSCs, human dental pulp stem cells; ECM, extracellular matrix; AMP, amorphous magnesium phosphate; hBMSCs, human bone marrow-derived mesenchymal stem cells; HUVECs, human umbilical vein endothelial cells; VEGF, vascular endothelial growth factor; 3D, three-dimensional.