A Review of 3D Printing in Dentistry: Technologies, Affecting Factors, and Applications

Abstract

Three-dimensional (3D) printing technologies are advanced manufacturing technologies based on computer-aided design digital models to create personalized 3D objects automatically. They have been widely used in the industry, design, engineering, and manufacturing fields for nearly 30 years. Three-dimensional printing has many advantages in process engineering, with applications in dentistry ranging from the field of prosthodontics, oral and maxillofacial surgery, and oral implantology to orthodontics, endodontics, and periodontology. This review provides a practical and scientific overview of 3D printing technologies. First, it introduces current 3D printing technologies, including powder bed fusion, photopolymerization molding, and fused deposition modeling. Additionally, it introduces various factors affecting 3D printing metrics, such as mechanical properties and accuracy. The final section presents a summary of the clinical applications of 3D printing in dentistry, including manufacturing working models and main applications in the fields of prosthodontics, oral and maxillofacial surgery, and oral implantology. The 3D printing technologies have the advantages of high material utilization and the ability to manufacture a single complex geometry; nevertheless, they have the disadvantages of high cost and time-consuming postprocessing. The development of new materials and technologies will be the future trend of 3D printing in dentistry, and there is no denying that 3D printing will have a bright future.

Figure 1

Schematic diagram of three-dimensional (3D) technologies. (a) Digital light processing. (b) Stereolithography. (c) Fused deposition modeling.

Figure 2

Crowns are made with digital light processing at the setting of five different construction angles to investigate the effect of construction angle on the accuracy of products [32].

Figure 3

This figure shows the viscosity of zirconia suspension according to volume fraction, which reveals a pattern that with the increase in the volume fraction of zirconia, the viscosity also increases. The highest viscosity of 9025 ± 57 mPa is measured at the highest volume fraction of 58 vol% [56].

Figure 4

Influence of final sintering temperature on shrinkage of three-dimensional- (3D-) printed titanium samples. The shrinkage of length decreases from 900°C to 1000°C and increases from 1000°C to 1300°C, while the shrinkage of diameter increases from 900°C to 1200°C and decreases from 1200°C to 1300°C, and the range of changes is not equal [58].

Figure 5

Triangular models with different degree of sharpness (60°, 45°, 30°, 20°, 10°, and 5°). The height of all models is set at 15 mm, and the width of the bottom edge changes with the degree of sharpness [62].

Figure 6

The microscopic images of the different surfaces of three-dimensional (3D) printing technologies. SLA: stereolithography; SLS: selective laser sintering; FDM: fused deposition modeling; PJ: photo jet [65].

Figure 7

(a) The three-dimensional (3D) medical rapid prototyping model is obtained using powder bed and inkjet head 3D printing with the attached prebent reconstruction plate. (b) The prebent reconstruction plate based on the model is fixed on the residual bone [74].

Figure 8

Different surface smoothness of crown restorations reflects the different accuracy of three-dimensional (3D) printing and computer-aided design (CAD)/computer-aided manufacturing (CAM) technologies. (a) The crown restoration is fabricated using 3D printing. (b) The crown restoration is fabricated using subtractive manufacturing [88].

Figure 9

The computer-aided design (CAD)/computer-aided manufacturing (CAM) process of constructing a partial prosthesis framework. (Images from the study of Harb et al. [108])

Figure 10

The design and production process of the surgical guide. (a) Digital model of the mandible obtained by scanning. (b) Specify the implant position in the design software. (c) Design surgical guide. (d) Print surgical guide using stereolithography (SLA) [133].

Figure 11

Digital design process and construction of mandibular custom trays. (a) The standard mandibular edentulous cast. (b) Three-dimensional (3D) digital model after scanning of the cast. (c) Trim the edge area of the model. (d) Add handles to the model to form a tray. (e) The custom tray is printed using fused deposition modeling. (f) The tray and the original cast are highly compatible [31].