Monolithic CAD-CAM lithium disilicate versus monolithic CAD-CAM zirconia for single implant-supported posterior crowns using a digital workflow: A 3-year cross-sectional retrospective study.

Statement of Problem: Dentistry has evolved significantly with the introduction of digital technologies and materials; however, clinical evidence for the performance of the complete digital workflow for single implant-supported posterior crowns is lacking.
Purpose: The purpose of this cross-sectional retrospective clinical study was to compare the clinical outcomes of 2 types of implant-supported crown used to replace a single missing posterior tooth in a completely digital workflow: transocclusal screw-retained monolithic lithium disilicate crowns versus transocclusal screw-retained monolithic zirconia crowns.
Material and Methods: A total of 38 participants who had been provided with dental implants and transocclusal screw-retained monolithic lithium disilicate or zirconia single crowns were evaluated in the study. Clinical and esthetic outcomes were recorded after a 3-year follow-up.
Results: Both groups had comparable clinical outcomes with a survival rate of 100%. In the lithium disilicate group, 89% of the participants were free of technical complications, and 95%, in the zirconia group. Only 1 patient experienced minor chipping affecting a lithium disilicate crown. All complications were considered minor and were easily resolved, and none of the participants required replacement of a crown. No biological complications were recorded in either group.
Conclusions: Within the limitations of this cross-sectional retrospective clinical study, monolithic lithium disilicate and zirconia screw-retained single crowns fabricated using computer-aided design and computer-aided manufacturing (CAD-CAM) and a fully digital workflow were found to be reliable and suitable clinical options for restoring a posterior missing tooth on a dental implant.
(Copyright © 2019 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)