1Schupbach Ltd, Laboratory for Histology, Electron Microscopy and Imaging, CH-8800 Thalwil, Switzerland
2Cosmodent Clinic, CH-8001 Zurich, Switzerland
3Material Research and Surface Technologies, Nobel Biocare Services AG, CH-8302 Kloten, Switzerland
Received 6 April 2019; Accepted 6 May 2019; Published 2 June 2019
Academic Editor: Wen-Cheng Chen
Copyright © 2019 Peter Schupbach et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.