Preclinical and Clinical Investigations of Zirconia Dental Ceramics Fabricated by Additive Manufacturing Technologies (ZIRAMDENT)

The introduction of zirconia ceramics (ZrO2) into dentistry in the early 90s broke new grounds in broadening the clinical indications for prosthetic metal-free restorative solutions. Zirconia's appealing advantages compared to metals were sought in excellent biocompatibility, superior mechanical properties and naturally pleasing appearance. However, such invasive ceramic-to-metal transition was only possible due to the development and successful implementation of digitalised computer-aided design and manufacturing (CAD-CAM) technology into the ceramic processing workflow. Overall, the past three decades have witnessed the evolution of new generations of zirconia dental ceramics varying in composition, translucency, and mechanical response to accommodate comprehensive clinical indications. However, the currently prevailing CAD/CAM technology is based on subtractive milling process of preformed yttrium-containing zirconia presintered blanks by removing the material with expensive milling tools accumulating an environmentally unconscious abundance of waste material, up to 90 %, which goes against to EU`s call of employment of advanced materials and processes for the recovery and reuse of critical raw materials and/or their sustainable replacement to meet the Circular Economy agenda. Integration of additive manufacturing (AM) in dentistry should be regarded as a relentless opportunity to overcome conventional dissipative CAD-CAM milling drawbacks. ZIRAMDENT aims to validate the prospects of established and emerging AM technologies for zirconia dental ceramic fabrication. The preclinical in vitro investigation of zirconia ceramics manufactured by fused filament fabrication (FFF), thermoplastic 3D printing (T3DP) and stereolithography (SLA), three different AM technologies will be conducted by evaluating mechanical, optical, crystallographic and microstructural properties of AM-fabricated zirconia test samples. Besides, the AM techniques' accuracy and ability to reproduce clinically important marginal and occlusal details will be studied in detail, where special attention will be placed on simulation of real dental geometries of fixed partial dentures in clinically relevant environments and to identify possible future perspectives of AM technologies in dentistry. The proposed project group has clinical skills as well as research experience and knowledge to complete the proposed tasks. With the AM of dental ceramics, new technology will be introduced in Slovenia, that is currently not available. Precise printing od advanced prosthodontic suprastructures wil improve rehabilitation of demanding clinical cases.