Additive manufacturing techniques in prosthodontics: Where do we currently stand? A critical review

Purpose: The aim of this article was to critically review the current application of additive manufacturing (AM)/3D-printing techniques in prosthodontics and to highlight the influence of various technical factors involved in different AM technologies.
Materials and Methods: A standard approach of searching MEDLINE, EMBASE, and Google Scholar databases was followed. The following search terms were used: (Prosth* OR Restoration) AND (Prototype OR Additive Manufacture* OR Compute* OR 3D-print* OR CAD/CAM) AND (Dentistry OR Dental). Hand searching the reference lists of the included articles and personal connections revealed additional relevant articles. Selection criteria were any article written in English and reporting on the application of AM in prosthodontics from 1990 to February 2016.
Results: From a total of 4,290 articles identified, 33 were seen as relevant. Of these, 3 were narrative reviews, 18 were in vitro studies, and 12 were clinical in vivo studies. Different AM technologies are applied in prosthodontics, directly and indirectly, for the fabrication of fixed metal copings, metal frameworks for removable partial dentures, and plastic mock-ups and resin patterns for further conventional metal castings. Technical factors involved in different AM techniques influence the overall quality, the mechanical properties of the printed parts, and the total cost and manufacturing time.
Conclusion: AM is promising and offers new possibilities in the field of prosthodontics, though its application is still limited. An understanding of these limitations and of developments in material science is crucial prior to considering AM as an acceptable method for the fabrication of dental prostheses.