[Development of nanostructured zirconia as a 3D-printing material for dental applications]

“This thesis studies the production of dental prosthetic structures from zirconia through the 3D printing method. In the theoretical part, ceramic materials are described, and the properties of zirconia are analyzed both in general and in the field of dentistry. Zirconia is a ceramic with strong mechanical strength and has been suitable for applications in this field in recent years. In addition, in the theoretical part, 3D printing techniques are developed, especially Inkjet printing (IJP) and Direct ink writing (DIW- robocasting). 3D printing techniques have wide application in manufacturing complex shapes and geometries where conventional production methods do not respond and are not economically viable. 3D printing is now also used in the field of dentistry with positive results.
The experimental part includes the preparation of tetragonal zirconia stabilized with yttria (Y-TZP) by the sol-gel and co-precipitation methods. Y-TZP is widely used in biomaterials science and now in dentistry, for the manufacture of implants, bridges, crowns, and abutments. Characterization of the produced zirconia was done by X-ray diffraction (XRD) and using transmission electron microscopy (TEM). So, we checked its structure and confirmed the creation of zirconia in nanoparticles. We prepared suspensions and pastes for printing by using the zirconia powder and the appropriate quantity and type of dispersant, monomer and binder.
Next, we selected the appropriate samples for printing on 2 different 3-d printers. The best results were 3 samples of organic zirconia precursors of 56.5% w/w solid percentage. After printing, the samples were de-binded and sintered to obtain their final density and porosity. We used a scanning electron microscope (SEM) to study their microstructure. Archimedes method was used for measuring their open porosity and density. The sample with the best results appeared to be ZrO23Y-O1 with additives: 0.9% Dolapix CE64 (dispersant), 0.09% Acrylamide (monomer) and 0.009% N-N’ Methylenebis Acrylamide (connector).”