143
build material are selectively deposited, (5) powder bed fusion (PBF): thermal
energy selectively fuses regions of a powder bed, (6) sheet lamination (SL): the
sheets of material are bonded to form an object and (7) vat photopolymerization
(PP): ultraviolet (UV) laser is scanned by vectors on top of a bath of a photopolymerizable liquid material. Stereolithography (STL), a PP technique, and selective laser sintering (SLS), part of PBF, are the most popular additive manufacturing
technologies for dental applications (Braian et al. 2016). Table 7.1 shows the main
advantages and disadvantages of RP techniques mainly used in dental medicine.
7.3 3D Printed Polymers in Dentistry
Three main classes of materials are currently used in dentistry: ceramics, metallic
materials and polymers. Another class of dental materials are composite materials
obtained by mixing any of the three main classes mentioned above. The latter, due
to their versatility and the modification of the structure, are tailored according to the
specific use designed. In particular, polymer composites are used in various dental
fields, such as endodontics, oral and maxillofacial surgery, orthodontics, restorative
dentistry, or for educational purposes.
7.3.1 3D Printed Polymers for Prosthetic Dentistry
3D printed polymers in prosthodontics are widely used for the fabrication of fixed
and provisional dental restorations (bridges and crowns), try-in and full dentures for
long-term use (Cristache et al. 2019). An overview of the different polymers used
for 3D printing in prosthetic dentistry is presented in Fig. 7.1. Recently, PEEK was
introduced as a 3D printed material for the manufacture of frameworks and removable denture components with the aim of replacing metal structures, resulting in
materials with good biocompatibility and high mechanical resistance. It should be
noted that these materials require several characteristics for an ideal dental restoration including: aesthetic appearance, antibacterial properties, biocompatibility,
mechanical resistance, precision, among others.
One of the main problems related to the use of some additive polymers manufactured in the biological environment is their natural toxicity. Auxilary compounds
such as monomers, photo-initiators and short-chain polymers for improving aesthetic, mechanical, and physical properties, can be released from the final printed
piece, in the oral environment, and consequently, can compromise biocompatibility.
Two main mechanisms are described by which compounds can be released from a
polymerized object: (1) degradation or erosion and (2) extraction by aqueous (or
solvent) medium, called leaching (Carve and Wlodkowic 2018). To remove these
potentially toxic compounds, manufacturer-recommended standard cleaning procedures are required after processing.
7 3D Printing-Processed Polymers for Dental Applications
build material are selectively deposited, (5) powder bed fusion (PBF): thermal
energy selectively fuses regions of a powder bed, (6) sheet lamination (SL): the
sheets of material are bonded to form an object and (7) vat photopolymerization
(PP): ultraviolet (UV) laser is scanned by vectors on top of a bath of a photopolymerizable liquid material. Stereolithography (STL), a PP technique, and selective laser sintering (SLS), part of PBF, are the most popular additive manufacturing
technologies for dental applications (Braian et al. 2016). Table 7.1 shows the main
advantages and disadvantages of RP techniques mainly used in dental medicine.
7.3 3D Printed Polymers in Dentistry
Three main classes of materials are currently used in dentistry: ceramics, metallic
materials and polymers. Another class of dental materials are composite materials
obtained by mixing any of the three main classes mentioned above. The latter, due
to their versatility and the modification of the structure, are tailored according to the
specific use designed. In particular, polymer composites are used in various dental
fields, such as endodontics, oral and maxillofacial surgery, orthodontics, restorative
dentistry, or for educational purposes.
7.3.1 3D Printed Polymers for Prosthetic Dentistry
3D printed polymers in prosthodontics are widely used for the fabrication of fixed
and provisional dental restorations (bridges and crowns), try-in and full dentures for
long-term use (Cristache et al. 2019). An overview of the different polymers used
for 3D printing in prosthetic dentistry is presented in Fig. 7.1. Recently, PEEK was
introduced as a 3D printed material for the manufacture of frameworks and removable denture components with the aim of replacing metal structures, resulting in
materials with good biocompatibility and high mechanical resistance. It should be
noted that these materials require several characteristics for an ideal dental restoration including: aesthetic appearance, antibacterial properties, biocompatibility,
mechanical resistance, precision, among others.
One of the main problems related to the use of some additive polymers manufactured in the biological environment is their natural toxicity. Auxilary compounds
such as monomers, photo-initiators and short-chain polymers for improving aesthetic, mechanical, and physical properties, can be released from the final printed
piece, in the oral environment, and consequently, can compromise biocompatibility.
Two main mechanisms are described by which compounds can be released from a
polymerized object: (1) degradation or erosion and (2) extraction by aqueous (or
solvent) medium, called leaching (Carve and Wlodkowic 2018). To remove these
potentially toxic compounds, manufacturer-recommended standard cleaning procedures are required after processing.
7 3D Printing-Processed Polymers for Dental Applications