Abstract
Aims: This study investigates the impact of ceramic material on the marginal gap of computer-aided design and computer-aided manufacturing (CAD/CAM) endocrowns using lithium disilicate (IPS e.max) and zirconia-reinforced lithium silicate (Suprinity).Materials and
Methods: In this in vitro experimental study, 24 extracted mandibular first molars, free of cracks, fractures, abnormal morphology, previous endodontic treatment, or restorations, underwent standardized endocrown preparation. The teeth were randomly assigned to two groups (n = 12) for endocrown fabrication using either lithium disilicate (IPS e.max CAD) or zirconia-reinforced lithium silicate (Suprinity). Teeth were scanned with a CAD scanner, and endocrowns were designed using inLab Software version 15 (inLab SW 15) and milled with an imes-icore 350i milling machine. Marginal gap was measured using the replica technique. Data were analyzed using one-way analysis of variance (ANOVA), t-test, and covariance analysis, with a statistical significance threshold of P < 0.05.
Results: Zirconia-reinforced lithium silicate (Suprinity) endocrowns exhibited a significantly higher mean marginal gap (82.95 ± 15.14 μm) compared to IPS e.max (76.22 ± 6.72 μm) across buccal, lingual, mesial, and distal surfaces (P < 0.05, Cohen’s d = 0.58). Specifically, mean marginal gaps were: buccal (82.33 ± 11.85 μm vs. 76.21 ± 5.80 μm), lingual (83.12 ± 14.61 μm vs. 77.17 ± 6.29 μm), mesial (84.08 ± 17.33 μm vs. 76.54 ± 6.30 μm), and distal (82.27 ± 16.76 μm vs. 75.00 ± 8.48 μm) for Suprinity and IPS e.max, respectively.
Conclusion: IPS e.max endocrowns demonstrated significantly lower marginal gaps compared to zirconia-reinforced lithium silicate, suggesting that IPS e.max may enhance marginal integrity and reduce microleakage in endocrown restorations.