Evaluation of Marginal Fit of Lithium Disilicate and Advanced Lithium Disilicate Crowns Using Two Intraoral Scanners: An In Vitro Study

his in vitro study aimed to evaluate and compare the marginal fit, accuracy, and precision of lithium disilicate crowns fabricated using two intraoral scanners—Primescan AC (Dentsply Sirona) and Medit i700 (Medit Corp., South Korea)—and two CAD/CAM ceramic materials (IPS e.max CAD and CEREC Tessera™). A mandibular first premolar was virtually prepared using CAD software and 3D printed to create a master die. Digital impressions were obtained using both scanners, and crowns were fabricated from IPS e.max CAD and CEREC Tessera™ blocks. Marginal fit was evaluated using the Triple Scan Technique, while accuracy (trueness) and precision (repeatability) were analyzed using Geomagic Control X software. Statistical analysis included two-way ANOVA and independent t-tests with significance set at p<0.05. No statistically significant differences were found in marginal adaptation between the two ceramic materials (p=0.880) or between scanners (p=0.512). However, Primescan demonstrated significantly better trueness (15.15±2.52 µm vs. 18.31±2.53 µm, p=0.012) and precision (7.73±1.62 µm vs. 10.03±0.72 µm, p<0.001) compared to Medit i700. Within the limitations of this in vitro study, Primescan showed superior trueness and precision compared to Medit i700. No significant difference in marginal fit was observed between IPS e.max CAD and CEREC Tessera™ crowns.