Advanced 3D Insights Into the Marginal and Internal Fit of Ceramic-Filled Hybrid Endocrowns With Variable Preparations.

Objective: This study aims to evaluate the influence of different preparation designs on the marginal and internal fit of 3D-printed permanent endocrowns using circumferential 3D analysis.

Materials and methods: Maxillary right first molar typodont teeth were prepared with four designs (n = 12); Group 1-butt joint & 2 mm pulp chamber, Group 2-butt joint & 4 mm pulp chamber, Group 3-shoulder & 2 mm pulp chamber, and Group 4-shoulder & 4 mm pulp chamber. Teeth were scanned, replicated as 3D-printed master dies, and restored with 3D-printed ceramic-filled hybrid endocrowns. After seating with Fit Checker, superimposed scans were analyzed circumferentially at standard points. Marginal, internal, pulp chamber, and overall gap values were measured from mesiodistal, buccolingual, and oblique sections. Statistical analysis was performed using two-way anova and post hoc Tukey tests (α = 0.05).

Results: Margin design and pulp chamber depth interactions revealed significant differences (p < 0.05). The least marginal fit was in Group 2, while the best internal and overall fit was in Group 3 (p < 0.05).

Conclusion: Different preparation designs have an impact on the fit of endocrowns. A shoulder margin design and a 2-mm pulp chamber depth exhibited a better internal fit of 3D-printed ceramic-filled hybrid endocrowns through circumferential 3D analysis.

Clinical significance: Circumferential 3D analysis reveals that variable preparation designs significantly influence the fit of endocrowns, guiding clinicians in selecting optimal designs for improved clinical outcomes.