Internal Adaptation of Endocrowns Fabricated Using Different Techniques: A Micro-CT Evaluation

Statement of Problem Endodontically treated teeth are prone to fracturing due to significant loss of structural integrity. Endocrowns are widely used to restore such teeth, but the optimal fabrication technique and material for proper adaptation remain unclear. Aim of Study This study aimed to compare the internal adaptation of endocrowns fabricated by three different techniques that is: milled Cerasmart (hybrid nanoceramic), 3D printed P crown V4 (hybrid nanoceramic), and pressed lithium disilicate (glass ceramic), using Micro-computed tomography imaging technique. Materials and Methods Thirty mandibular first molars were prepared for endocrowns using a Computerized Numerical Control (CNC) milling machine (Iraq) and divided into three groups (n = 10) based on the fabrication technique: Group A : Nanoceramic Hybrid blocks (Cerasmart, Gc Corporation, Japan), Group B : 3D printed nanoceramic hybrid materials (P-Crown V4, Senertek, Turkey). Group C : Pressed lithium disilicate ingots (IPS e.max Press, Ivoclar, Liechtenstein). Endocrowns were designed and fabricated using CAD software. Micro-CT scanning was performed using LOTUS in Vivo scanner. Internal adaptation was measured at 54 points per specimen. Two-way ANOVA and One -Way ANOVA were used for statistical analysis. Results For internal adaptation, Group B (3D printed) consistently demonstrated higher gap values (149 ± 17µm) compared to Group A (milled, 130 ± 23µm) and Group C (pressed, 129 ± 27.14µm). Groups A and C showed lower values for the cervical seat, axial wall, and pulpal floor measurements than group B. Conclusion While milled hybrid resin endocrowns demonstrated superior adaptation, all three fabrication techniques produced restorations within clinically acceptable ranges. The choice of material and fabrication method should be based on specific clinical situations, considering factors such as esthetics, strength requirements, and cost-effectiveness. Clinical significance Milled nanoceramic endocrowns showed the best adaptation, enhancing restoration longevity. All techniques were clinically acceptable, but 3D-printed crowns had larger gaps, potentially affecting durability. Material choice should consider esthetics, strength, and cost. Proper adaptation is crucial for endodontically treated teeth, impacting clinical success and long-term patient outcomes.