Vat polymerization-printed partially stabilized zirconia: Mechanical properties, reliability and structural defects

Additively Manufactured Zirconia for Dental Applications

“…In the present study, the building direction of LithaCon 3Y 230 (Lithoz) and 3D Mix zirconia (3DCeram Sinto) was different: LithaCon 3Y 230 (Lithoz) was printed horizontally to the load direction, whereas 3D Mix zirconia (3DCeram Sinto) was printed vertically to the load direction. In general, specimens in which the building and tensile loading direction are parallel (Figure 1a) have an inferior flexural strength than specimens which are loaded perpendicularly to the building direction (Figure 1b) [9]. Our results were in line with a previous study reported by Bergler et al (2021), which showed comparable flexural strength for both additively and subtractively manufactured zirconia [27].…”

“…Among different techniques, few methodologies can be used to fabricate fully dense ceramic, with stereolithography being one of the most promising techniques [4][5][6][7][8]. It has also been shown that zirconia ceramic can be fabricated with sufficient accuracy and strength [9,10]. Current commercially available equipment makes use of two different technologies, being direct light processing (DLP) and laserbased stereolithography (SLA) [11].…”

Additive manufacturing of zirconia ceramics by material jetting

“…The Vickers hardness [56] and indentation fracture resistance [33,43,57,58] values are in agreement with the reported literature data for 3Y-TZP with similar grain size, as determined by Vickers indentation and SEVNB with similar well-defined sharp cracks. Since the layer lines are not visible anymore after sintering, the fracture toughness did not differ for the different printing directions [59].…”

“…The reported defects were porosity, thermal cracks and a rough surface, which all reduced bending strength [5,8]. The defects observed in SLA-produced ZrO2 ceramics were agglomerates, delaminations, cracks caused by differential shrinkage and insufficient layer bonding, pores due to air bubbles present in the slurry during printing, and post-processing induced damage [41,42,47,49,59,[67][68][69][70]. Mechanical properties and the reliability of the sintered ceramics were often anisotropic, related to weaker connections between the layers in the building direction, pores, agglomerates or due to surface defects caused by post-processing [41,42,47,69,70] 9, the bending strength in the X-or 0°-direction is comparable to the reported values in this paper for MJ.…”

Digital light processing stereolithography of zirconia ceramics: Slurry elaboration and orientation-reliant mechanical properties

“…In addition, fewer cracks and interlayer flaws were present in the materials at the highest ceramic fractions. Further papers dealt with the characterization of the mechanical strength of DLP-printed zirconia ceramics [10,18], and few papers explored the role of printing orientation on the mechanical properties [19,20], but in such previous works the slurry preparation and its role on the final properties was not investigated. Therefore, the aim of this work is to provide a general overview of the main parameters able to affect the mechanical properties of zirconia ceramics fabricated by DLP.…”