357 DIGITAL DENTAL TECHNOLOGIES Volume 35, Number 3, 2022 Correspondence to: Dr Laurent Marchand 1, rue Michel-Servet 1211 Genève 4, Switzerland Email: laurent.marchand@unige.ch Submitted October 20, 2020; accepted February 24, 2021. ©2022 by Quintessence Publishing Co Inc. Digital Wear Analysis of Different CAD/ CAM–Fabricated Monolithic Ceramic Implant- Supported Single Crowns Using Two Optical Scanners Laurent Marchand, Dr Med Dent Division of Fixed Prosthodontics and Biomaterials, University Clinics of Dental Medicine, University of Geneva, Geneva, Switzerland. Irena Sailer, Prof Dr Med Dent Division of Fixed Prosthodontics and Biomaterials, University Clinics of Dental Medicine, University of Geneva, Geneva, Switzerland. Hyeonjong Lee, DMD, MSD, PhD Department of Prosthodontics, Dental Research Institute, School of Dentistry, Pusan National University, Yangsan, South Korea. Philippe Mojon, Dr Med Dent Division of Fixed Prosthodontics and Biomaterials, University Clinics of Dental Medicine, University of Geneva, Geneva, Switzerland; Division of Gerodontology and Removable Prosthodontics, University Clinics of Dental Medicine, University of Geneva, Geneva, Switzerland. Joao Pitta, Dr Med Dent, MAS Division of Fixed Prosthodontics and Biomaterials, University Clinics of Dental Medicine, University of Geneva, Geneva, Switzerland. Purpose: To digitally evaluate the volumetric wear of four different implant crown materials and their antagonists after artifcial aging using an intraoral scanner (IOS) device and a laboratory desktop scanner. Materials and Methods: A total of 48 implants were restored with monolithic crowns and divided into groups according to restorative material: lithium disilicate (LDS); zirconia (ZR); polymer-infltrated ceramic network (PICN); and porcelain fused to metal (PFM). Each specimen was scanned using a desktop scanner (LAB group; iScan D104, Imetric 3D) and an IOS device (IOS group; Trios 3, 3Shape) before and after chewing simulation (1,200,000 cycles, 49 N, steatite antagonist, 5°C to 50°C). The obtained STL fles were superimposed, and the volumetric loss of substance of the crowns and their antagonists was quantifed. Kruskal-Wallis, Spearman ρ, and paired t tests were used to analyze the data (α = .05). Results: The mean volume loss for each restorative material varied between 0.05 ± 0.06 mm 3 (ZR/IOS) and 3.42 ± 1.65 mm 3 (LDS/LAB). The wear of the antagonists was signifcantly lower (P < .05) for ZR than the other groups. Increased wear of the crowns was highly correlated with increased wear of their antagonists (r s = 0.859). When comparing the wear measurement using the two scanning devices, no difference in mean volume loss was found (IOS: 1.81 ± 1.81 mm 3 ; LAB: 1.82 ± 1.78 mm 3 ) (P = .596). Conclusion: Polished ZR was the most wear-resistant material and the least abrasive to the respective antagonist among the tested ceramics. For quantifcation of wear, this IOS device can be used as an alternative to desktop scanners. Int J Prosthodont 2022;35:357–364. doi: 10.11607/ijp.7430 “ W ear” is defned as the deterioration or loss of substance due to continu- ous use. As human teeth are in use on a daily basis, the wear of dental tissues such as enamel and dentin is of relevance. 1 Apart from natural tooth substance, the wear behavior of dental materials is of great interest to ensure their longevity and the stability of the antagonist dentition. This assumes a particular importance when restoring dental implants. As previously reported, the reduced proprioception of an implant may lead to higher forces during function and possibly higher wear of the restoration and its antagonists. 2–4 © 2022 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART M AY BE REPRODUCED OR TRANSM ITTED IN ANY FORM WITHOUT WRITTEN PERM ISSION FROM THE PUBLISHER.