Evaluation of stress distribution and initial stability of different shield thicknesses in the socket shield...

This study investigated the biomechanical effects of shield thickness in the socket shield technique under immediate implant loading using high-fidelity three-dimensional finite element analysis. A maxillary model was developed incorporating cortical bone, cancellous bone, labial root fragment (shield), implant, abutment, and crown, with high anatomical fidelity to clinical conditions. Four shield thicknesses (0.5, 1.0, 1.5, and 2.0 mm) were evaluated. Axial (0°) and oblique (30°) loads of 158.6 N were applied, and an abutment preload of 450 N was introduced to simulate prosthetic prestress. Equivalent stress, maximum principal stress, and total deformation of the shield, implant, and peri-implant bone were quantified. The biomechanical response exhibited nonlinear characteristics. Shield stress increased from 0.5 to 1.0 mm, peaked at 1.5 mm, and decreased at 2.0 mm, whereas total deformation increased progressively with increasing thickness. Peri-implant bone stress was concentrated at the shield-labial cortical bone interface and decreased as shield thickness increased. Implant stress reached its maximum at 1.5 mm and decreased toward both thinner and thicker configurations. A shield thickness of 1.0-1.5 mm demonstrated a favorable biomechanical balance between stress distribution and deformation control, potentially contributing to peri-implant bone preservation and enhanced early implant stability under clinically relevant loading conditions.