Digital workflow impact on CAD/CAM crown accuracy: a five-protocol comparison

Heba Ismail; Seif Elgayar; Ahmad Aboelfadl; Tarek Salah; Nancy Rafla

doi:10.4322/bds.2026.e5051

Authors

Heba Ismail Ain Shams University, Faculty of Dentistry, Fixed Prosthodontics Department. Cairo, Egypt. https://orcid.org/0000-0002-2345-8175
Seif Elgayar Ain Shams University, Faculty of Dentistry, Fixed Prosthodontics Department. Cairo, Egypt. https://orcid.org/0009-0006-9124-2479
Ahmad Aboelfadl Ain Shams University, Faculty of Dentistry, Fixed Prosthodontics Department. Cairo, Egypt. https://orcid.org/0000-0002-7010-7933
Tarek Salah Ain Shams University, Faculty of Dentistry, Fixed Prosthodontics Department. Cairo, Egypt. https://orcid.org/0000-0001-6724-9458
Nancy Rafla Ain Shams University, Faculty of Dentistry, Fixed Prosthodontics Department. Cairo, Egypt. https://orcid.org/0000-0001-7614-2871

DOI:

https://doi.org/10.4322/bds.2026.e5051

Abstract

Objective: The objective of this in-vitro study was to assess and compare the marginal adaptation and internal fit of zirconia-reinforced lithium silicate (ZLS) ceramic crowns produced utilising five distinct digital protocols that include multiple scanners, software, and milling machines. Material and Methods: Fifty ceramic crowns were produced from Celtra Duo blocks utilising five digital protocols: (A) CEREC Omnicam + CEREC Premium SW + MCXL; (B) CEREC Omnicam + CEREC Connect SW + MCXL; (C) CEREC Omnicam + CEREC Connect SW + MCX5; (D) InEos X5 + InLab SW + MCXL; (E) InEos X5 + InLab SW + MCX5. The replica technique was used to measure the internal fit at seven set points. While digital microscopy at 50× magnification was used to measure the marginal adaptation across four surfaces. Two-way ANOVA and Tukey’s post hoc test (α=0.05) were used to analyze the data. Results: Significant differences were identified among digital procedures for both internal fit and marginal adaptation (p<0.001). Group E had the superior results, with an internal fit of 180.41±27.22 μm and a marginal adaptation of 55.80±16.49 μm. Group B had the worst internal fit (294.07±18.29 μm), whereas Group A had the worst marginal adaptation (133.93±41.51 μm). The central fossa always had the highest internal gap values for all groups. Conclusion: Digital protocol has a great impact on how well ZLS ceramic restorations fit in both marginal adaptation and internal fit. Laboratory-based workflows utilising 5-axis milling (Group E) demonstrated greater fit relative to chairside systems, however data transfer using connect software adversely affected restoration accuracy.

KEYWORDS

CAD/CAM; Digital technology; Internal fit; Marginal adaptation; Zirconia-reinforced lithium silicate.