Since it was initiated in March 2011, in Stockholm, Sweden, the International Workshop on Advanced Ceramics and Technologies for Dentistry (ACT4D) has been held regularly, each time ended up a volume of publication as special issue either of Journal of the European Ceramic Society or of the Advance in Applied Ceramics. The articles included in this special issue were selected from those works presented and discussed in ACT4D 2019 held on the 17–19th of March, 2019, in Stockholm. The aim of ACT4D has always been to provide a forum for multidisciplinary brainstorm and discussions between ceramists, engineers and clinicians devoted to dentistry with the focus on challenges encountered by the current and the emerging technologies, as well as future concepts going beyond the state of the art. A characteristic routine has been established to seek the works related to (i) the developing and customised manufacturing of novel advanced ceramics with improved performances, (ii) the fundamental understanding of the interactions between ceramics (on the micro-to-nanoscale level) and hard-to-soft tissues (on protein and cell level), (iii) the reliability of ceramic parts in relation to their hierarchical microstructures and of the feasibility of fitting the ceramic processes into a full digital clinic approach, and (iv) the advanced technologies enabling the establishment of an ecosystem based on model-free digital workflows.
Many materials, including ceramics, metal alloys and polymers, have been adopted for dental applications, among them only very few were originally developed for dental purposes. Zirconia is one typical example that is commonly used today and has the potential to become the dominating ceramic material that perfectly fits for the future digital dentistry, but its initial development was driven by other purposes that have no relevance with dentistry at all. On one side, dentists are a group of practitioners who are brave enough to adopt new materials in their daily practices. On the other side, ceramists hardly treat dentistry as a priority application area of the new ceramic materials they developed, neglecting the fact that artificial teeth are one of the very few man-made products that every individual may need in their lifetime. The workshop ACT4D brought dentists and ceramists together to bridge this knowledge gap and to encourage joint efforts for the development of new advanced ceramics and technologies for dentistry. It would thus attract ceramists to pay more attention to dental practice where what is needed is to imitate the functions, but not necessary the chemistry and structures of natural teeth, and respectively help dentists to understand that the processes for manufacturing and applying ceramics are as, if not even more, crucial as the ceramic materials themselves.
The theme of ‘Materializing Digital Solutions for Dentistry’ was particularly emphasised in this 3rd workshop to reveal the timely importance of materials that are, in fact, the materialised technological solutions and cornerstones of modern restorative dentistry in the coming digital era. Seeing a clear tendency for dentistry towards digitalisation and of the expanding applications of advanced ceramics, not only as prostheses but also as implants, this time we emphasised also other advanced technologies besides advanced ceramics. The obviously increased number of topics and the number of articles selected on each topic in this special issue reflect the current status of this filed of both strong fundamental and application interests. The 17 articles selected cover digital net-shape manufacturing of zirconia prostheses both by additive and subtractive principles (3 articles), evaluating the dimensional accuracy (1 article), developing new forming techniques (1 article), characterising the optical properties of zirconia (1 article), developing methods for improving the bonding of zirconia prostheses with natural teeth (1 article), clinical approval of the prostheses made of self-glazed zirconia (5 articles), bacterial adhesion and biofilm formation on zirconia (1 article), robotic tooth preparation (1 article) and inorganic dental cements (4 article).
It would be impossible to have prepared this special issue ready for publication without the encouragement and practical help of Professor Michael J Reece. He himself handled, as a co-editor-in chief, the reviewing process for quite high portion of the manuscripts. Finally, I would thank all the authors and reviewers once again for your trust and for your efforts in submitting manuscripts and reviewing papers in good time.
The workshop was organised jointly by the Department of Materials and Environmental Chemistry at Stockholm University and Ceravik AB, and partially sponsored by the JECS Trust.