Stereolithography-based additive manufacturing of lithium disilicate glass ceramic for dental applications.

With additive manufacturing (AM) on the rise in industrial production, different industries are looking for a way to benefit from the advantages over conventional manufacturing methods like milling or casting. The layer by layer approach allows the parallel construction of different complex structures with simultaneous customization of the parts, while waste material is significantly reduced. This is especially interesting for the processing of advanced ceramic materials, where often customized and single parts are required. Regarding ceramics, Lithographic Ceramic Manufacturing (LCM) provides the highest surface quality and achievable precision compared to any other AM technologies, which is necessary to meet the high demands from dental industry regarding accuracy and reproducibility. At TU Wien, we achieved expertise in printing different kinds of ceramics and glasses by using specially developed stereolithography printers based on digital light processing (DLP) followed by a thermal debinding and sintering processes. In dental industry, glass ceramic materials are widely used for customized and aesthetic restorations. This work deals with the processing of lithium disilicate via an AM technology, offering highly dense (>99%), full ceramic parts which meet the requirements for the use as dental restorations. With outstanding mechanical properties of over 400 MPa flexural strength, excellent translucency and accuracy, veneers, crowns and even bridges, especially for the anterior tooth area can be reproducibly printed, debinded and sintered.