For dental applications, CAD/CAM processes have been the dominant manufacturing method for dental restorations in recent decades. But due to the high mechanical force of the rotating tool and the limited resolution of the tool diameter, CAD/CAM technology reaches its limits when it comes to production of veneers thinner than 0.4 mm or the fissures of natural teeth. Over the past years additive manufacturing (3D printing) has become an integral part of modern medical engineering since 3D-printing is proving to be a cost-effective, sustainable, and scalable alternative. The biggest motivation of using 3D-printing for dental restorations are the significantly reduced material waste and the ability to overcome limitations or drawbacks of CAD/CAM as 3D-printing can produce unprecedented detail in fissure geometries and significantly thinner veneers. The manufacturing of ceramic restorations, using lithography-based ceramic manufacturing (LCM) technology, is a two-step process. The base material is a slurry, which basically consists of ceramic powder and a photocurable binder. In the first step, a so-called green part, a ceramic/photopolymer composite is built up layer by layer by using a DLP system. The second step involves the debinding and crystallization of the lithium disilicate with subsequent staining and glazing.
This study focuses on the production workflow of 3D printed lithium disilicate dental restorations based on a clinical case. The fit of the prostheses and aesthetic results were evaluated, and the 3D printed material was analyzed regarding its leachability, cytotoxicity, and residual carbon content, and the data was compared to conventional CAD/CAM manufactured lithium disilicate. In the context of the presentation, the possibilities of the LCM process for modern medical engineering will be shown on the base of different ceramics and applications. Beside preclinical data, also insights into the first clinical examination will be presented. In addition to monolithic samples, preliminary results of multi-material printing of lithium disilicate ceramics with various color ranges will be presented.