Table 1.

Comparison of main RP technologies

RP technology	Materials	Advantages	Disadvantages
SLA	PEG, PEGDA, PPF, PCL, PDLLA	Fast speed, high resolution, easy to remove support materials	Limited range of photosensitive resin and polymers
SLS	Polymers, ceramics (PCL, HA, TCP)	Wide range of materials, good mechanical strength, relatively high precision, high porosity	Materials in powder form, difficult to remove trapped materials
FDM	Thermoplastic polymers and their composites	Easy operation, low cost, various lay-down patterns	Materials in filament form, low speed, high temperature, smooth surface
3DF	Thermoplastic polymers and their composites, hydrogels	Easy operation, low cost, materials in pellet form, reduced preparation time	High temperature
PED	PCL, PCL-HA	Materials in pellet form	High temperature
PEM	PLLA, PLLA-TCP	Materials in grain form	High temperature
LDM	PLLA, PLGA, collagen, gelatin, chitosan, alginate	Materials in grain form, retain bioactive agents, can incorporate biomolecules	Need solvent and freeze drying process
Robocasting	Ceramics, organic inks	Wide range of materials, multi-material is possible	Difficult operation
3D bioplotting	TCP, PCL, PLGA, PLLA, soft tissue	Remarkably wide range of materials, biomolecules can be used	Low mechanical strength, smooth surface, slow speed, difficult operation
3DP	Cermics, polymers, metals	Fast speed, low cost, wide range of materials	Need post-processing, powdery surface

RP: rapid prototyping; SLA: stereolithography; SLS: selective laser sintering; FDM: fused deposition modeling; 3DF: 3D fiber deposition; PED: precision extrusion deposition; PEM: precise extrusion manufacturing; LDM: low-temperature deposition modeling; 3DP: 3D printing; PEG: polyethyleneglycol; PEGDA: poly(ethylene glycol) diacrylate; PPF: polypropylene fumarate; PCL: polycaprolactone; PDLLA: poly-D , L-lactatide; HA: hydroxyapatite; TCP: tricalcium phosphate; PLLA: poly-L-lactatide; PLGA: polylactide-co-glycolide