Since the beginning, ZrO₂-based materials attracted the attention of the scientific community due to the synergistic combination of unique physical, chemical and structural properties, including biocompatibility, high wear resistance, and outstanding mechanical performances. In fact, the stabilization of tetragonal zirconia polycrystal (TZP) at room temperature achieved by adding proper stabilizers such as yttria (Y₂O₃), ceria (CeO₂), magnesia (MgO) or calcia (CaO), and the tetragonal-to-monoclinic transformation under an applied stress, provide toughening and strengthening effects.
Concerning biomedical applications, inter alia, dental implants, maxillofacial and articular prostheses for load-bearing sites, many efforts have been done to improve the stability of ZrO₂-based components upon exposure to an aqueous environment, thus minimizing low temperature degradation (LTD) phenomena, also known by the name of zirconia ageing. In this frame, it is well recognized the positive role of CeO₂ stabilizer, compared to Y₂O₃ one, to reduce or completely avoid the sensitivity of zirconia to ageing. Despite this, Ce-TZP components are notoriously affected by low mechanical resistance due to the significant grain growth occurring upon sintering, but this issue is usually successfully addressed by elaborating composite materials trough the introduction of second phases within the matrix.
The appealing possibility to realize complex finished objects starting from a Computer-Aided Design (CAD) file was the main driving force which led, in recent years, to the increasing popularity of ceramic stereolithography in different research fields, from medicine to environmental applications.
To date, several advanced ceramics such as alumina (Al₂O₃), zirconia (ZrO₂) and silicon nitride (Si₃N₄) have been processed by ceramic stereolithography to produce high-resolution components with customizable intricate geometries and superior surface quality, not achievable by conventional processing techniques. 
Interestingly, the advent of stereolithography in ceramic processing introduced additional challenges in the manufacturing of Ce-TZP parts due to the significant absorbance of ceria in the UV range, responsible for reducing photopolymerization efficiency.
The present study methodically addresses open challenges related to the shaping through digital light processing (DLP) of ceria-stabilized ZrO₂ composites, with a focus on the effect of second phases on zirconia transformability, microstructural and mechanical properties.
Highly homogeneous composite materials with increasing phase composition complexity, i.e., Ce-TZP, Ce-TZP/α-Al₂O₃ and Ce-TZP/α-Al₂O₃/SrAl₁₂O₁₉, were produced by an innovative processing route based on a wet surface coating approach, starting from a commercial powder. Different dispersion conditions were implemented to reduce particle size to specific ranges. Slurry rheology was fine-tuned to maximize the solid loading by properly balancing resin and dispersing agent, while printing parameters have been set on the basis of slurry properties. In order to do this, a standardized procedure was specifically optimized to achieve almost defect-free and highly dense components (ρ≥99%). The quantification of the tetragonal-to-monoclinic transformation was determined by Toraya’s equation from X-Ray Diffraction Analysis (XRD), while microstructural features and grain size distribution were assessed by Scanning Electron Microscopy (SEM) and subsequent image post-processing. Finally, 3-point bending tests allowed to determine the effect of second phases on mechanical performances of dense components with high statistical accuracy.