Accuracy, Reproducibility, and Gaps in Different Angulations of 3D-Printed versus Milled Hybrid Ceramic Crown.

Abstract

Objectives:  This article compared the accuracy, reproducibility, and gap of crowns resulting from variations in print angulation of three-dimensional (3D)-printed VarseoSmile Crown^plus (VS) and milled resin-ceramic hybrid materials (Cerasmart 270, CS, and Enamic, E).

Materials and methods:  A total of 60 specimens, consisting of VS printed at four different angulations (30, 45, 60, and 90 degrees), along with CS and E were investigated. External and internal accuracy and reproducibility were measured with the 3D deviation analysis. External and internal gaps were measured with the silicone replica technique. The results were analyzed using Welch's one-way analysis of variance with Dunnett T3 post hoc comparison at p ≤ 0.05.

Results:  Across all groups, external and internal accuracy were 0.55 to 20.02 μm and external and internal reproducibility were 0.05 to 0.69 μm. Overall external accuracy was not significant (p = 0.063), whereas significance was noted in overall internal accuracy and reproducibility among groups (p < 0.001). External and internal gaps were 33.76 to 93.11 μm. Statistically significant differences were found in internal and external gaps among groups (p < 0.001), with milled crowns demonstrating larger internal and smaller external gaps than 3D-printed crowns. Within the 3D-printed group, statistically, 90-degree angles exhibited the smallest external and internal gaps.

Conclusion:  Both milled and 3D-printed methods achieved clinically acceptable accuracy, reproducibility, and gap dimensions, offering viable options for hybrid ceramic crown restoration. Among 3D-printed crowns, the 90-degree printing angle group exhibited satisfactory accuracy and reproducibility, alongside the best internal and external fit.