Design, fabrication, and characterization of novel dental implants with porosity gradient obtained by Selective Laser Melting
Amanda Robau-Porrúa, Jesús E. González, Roberto Arancibia-Castillo, Alberto Picardo, Eugenia A. Araneda-Hernández, Yadir Torres
Abstract
• Advanced SLM is suitable for manufacturing complex dental implant designs. • Design of new dental implants for immediate loads with porosity gradients. • Porous dental implants with radial porosity show a better biomechanical balance. • FEM a fast and effective tool to evaluate the stress shielding phenomenon. Porous dental implants represent a significant advancement in dentistry, offering improved osseointegration, reduced bone resorption and minimized stiffness to better interact with surrounding bone. This study focuses on the development of Ti6Al4V implants with immediate loading and controlled porosity (40 vol% and 600 µm pore size) to improve vascularization and bone ingrowth, which are crucial for successful integration and long-term performance. Dense implants, fully porous implants, and a hybrid design combining a porous surface with a dense core were fabricated using Selective Laser Melting, enhancing fatigue resistance under cyclic loads. Porosity was quantified, revealing 19 % through image analysis and 13 % via the Archimedes method. Finite Element Analysis demonstrated that porous implants improve stress distribution, facilitate load transfer to peri -implant trabecular bone, and achieve uniform stress and strain distributions between thread fillets, with values ranging from 1.1 MPa to 1.6 MPa for stress and 0.0002 to 0.0030 for strain, promoting bone growth. Comparisons with β-Ti alloy implants featuring a porous structure and dense core revealed reduced stress concentrations and a lower risk of fatigue failure. These findings highlight the potential of hybrid and β-Ti designs for personalized dental implants, balancing mechanical performance with biological compatibility to meet patient-specific needs.