Table 4.

Challenges and possible solutions for 3D printing bioactive ceramics.

Challenges	Solutions
Existing bioceramic scaffolds have insufficient toughness and are easy to fracture, so they cannot be used for bearing bones.	3D printing technology and bionic technology to prepare composite multi-materials, with excellent mechanical properties of 3D-printed bioceramic scaffold.
Clinical practice often requires the simultaneous treatment of the patient’s disease and repair of bone defects.	3D printing technology combined with drug-carrying materials and bone growth-promoting factors has developed a 3D-printed multifunctional bioceramic scaffold that can be used for both disease treatment and tissue regeneration. The scaffolds can both treat disease and promote bone tissue regeneration.
Existing 3D-printed bioceramics scaffolds are difficult to accurately mimic the highly complex and ordered microstructure of natural bone tissue.	Other micro-nano manufacturing technologies—such as hydrothermal processing, laser engraving, and electrospinning—are being combined with existing 3D printing technologies to produce scaffolds with finer structures.
Existing 3D-printed bioceramic scaffolds cannot restore the full function of bone tissue.	Through the multi-channel 3D printing technology, a variety of materials and cells are combined to simulate the real situation of bone tissue in the body as much as possible.
Existing 3D printing technology is difficult to be accurate to the nanometer scale, and can only be made into a scaffold and change its shape through physical and chemical methods.	The development of nano-scale 3D printing technology can prepare multi-tissue scaffolds with spatial and functional regulation.