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3D Printing of Ceramic Dental Prostheses
is still need warranted to perfect their applications in this technique is suitable for fabrication of collapsible
the fabrication of dental implants, crown, and bridges molds made of ceramics or metallic material with high
denture and prosthetic constructions. Therefore, the temperature resistance.
main goal of this study is to propose and investigate the To evaluate the feasibility of this technique,
feasibility of a novel fabrication method based on ZrSiO - we applied multivariable approach to investigate the
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glass composite in dental prosthesis applications, such as main effect of control factors on responses. Holding
crowns, coupings, bridges, and dentures. The schematic temperature, holding time, heating rate, cooling rate,
of this method is illustrated in Figure 1. and shrinkage chamber were the control factors while
In this method, the collapsible ZrSiO mold of shrinkage, flexural strength, and process feasibility
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negative of crown or bridge was fabricated by AM were the study responses. The fabrication parameters,
based on fused filament fabrication (FFF). The negative formulation of materials, flexural testing specimen shape,
cavity was filled by lanthanum glass powder and sintered and crown shape were kept constant. This study helped
subsequently. In the end, the pieces were heated to debind determine whether the proposed method of indirect AM
the negative structure and then create sintered composite is feasible to fabricate ceramic dental prosthesis.
pieces.
It is also important to note that several AM 2. Materials and methods
techniques, such as inkjet printing and stereolithography,
generate objects with higher resolution than manufacturing To investigate the feasibility of the proposed method in
by FFF. However, these techniques are restricted by addition to the main effect of control factors on responses,
k
photopolymeric resins and slurry-based techniques. For we applied a 2 multivariable methodology (full design
that reason, they are mainly used for casting patterns, with body central point) where holding temperature (T ),
h
lost wax (resin), and investment casting [19,20] . In addition, holding time (t ), heating rate (R ), and cooling rate (R )
h
h
c
in spite of high resolution, these AM techniques were the control factors. In addition, we also defined
(stereolithography apparatus and Inkjet printing) imply three screening steps in augmented design approach to
on dimensional and geometrical accuracy equivalent minimize the holding time and maximize the densification
to FFF techniques [21-23] . In fact, the high resolution has and mechanical properties.
been shown to influence the roughness, rather than the The levels and values of each control factor are
dimensional accuracy [21-23] . Besides low cost, AM based presented in Table 2. The values of holding temperature
on FFF is able to fabricate objects with high amount of are between the activation temperature of glass and ZrSiO
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ceramic and metallic in their composition [24-26] . Thus, (700°C) and the melting temperature of glass (1078°C).

Figure 1. Schematic diagram of the fabrication of ceramic dental prosthesis using indirect additive manufacturing.

92 International Journal of Bioprinting (2021)–Volume 7, Issue 1