Related Experiment Video
Updated: Jul 3, 2026
Measuring the Complete-arch Distortion of an Optical Dental Impression
Published on: May 30, 2019
Marginal and internal fit of zirconia CAD-CAM fabricated with conventional impression and digital scanning
Nusaiba M Al-Odinee1, Afaf Al-Haddad2, Abdullah F Alshammari3
1PhD student, Department of Prosthodontics, Sana'a University, Sana'a, Yemen.
Statement Of Problem:
The accuracy of recording techniques plays a critical role in determining the marginal and internal fit of zirconia computer-aided design and computer-aided manufacture (CAD-CAM) restorations. However, the literature presents inconsistent findings regarding whether digital scanning provides better fit than conventional impressions.
Purpose:
The purpose of this systematic review and meta-analysis was to evaluate and compare the marginal and internal fit of zirconia CAD-CAM restorations fabricated using digital scanning techniques versus conventional recording techniques.
Material And Methods:
An electronic search of PubMed/MEDLINE, Scopus, and Web of Science databases was conducted to identify clinical studies that directly compared digital scanning and conventional recording techniques for zirconia CAD-CAM crowns and reported marginal and/or internal fit outcomes. Randomized clinical trials (RCTs) were assessed using the Cochrane Risk of Bias 2 (RoB 2) tool, while nonrandomized studies were evaluated using the ROBINS-I tool. Meta-analyses were performed to calculate pooled mean differences for marginal and internal fit using fixed- or random-effects models based on heterogeneity (α=.05).
Results:
Ten clinical studies met the inclusion criteria. Four randomized clinical trials demonstrated a low risk of bias, whereas 6 nonrandomized studies showed a moderate risk of bias. Meta-analysis revealed that digital scanning techniques resulted in significantly improved marginal fit (mean difference [MD]=-15.42 µm; 95% confidence interval [CI]: -29.75 to -1.08; P=.040) and internal fit (MD=-21.22 µm; 95% CI: -36.61 to -5.83; P=.007) compared with conventional impression techniques.
Conclusions:
Within the limitations of this systematic review and meta-analysis, digital scanning techniques demonstrated better marginal and internal fit for zirconia CAD-CAM restorations than conventional impression techniques, while both approaches produced clinically acceptable results.
