Gustavo Assis de Paula1, Guilherme Carvalho Silva2, Ênio Lacerda Vilaça3, Tulimar Machado Cornacchia2, Cláudia Silami de Magalhães4, Allyson Nogueira Moreira4. 1. Postgraduate, Department of Restorative Dentistry, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil. 2. Adjunct Professor, Department of Restorative Dentistry, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil. 3. Associate Professor, Department of Restorative Dentistry, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil. 4. Full Professor, Department of Restorative Dentistry, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
Abstract
PURPOSE: Biomechanical behavior of tooth-implant-supported prostheses (TISPs) with external and internal implants was compared. MATERIALS AND METHODS: Two 3-D models of TISP were designed by varying the implant: external (Model EH) and internal hexagons (Model IH). After loading, von Mises stresses were obtained in implants, abutments, and screws. Principal maximum (σmax) and minimum (σmin) stresses were analyzed in periodontal ligament (PL), alveolar bone, and periimplant bone. RESULTS: Model IH showed lower stress peaks in axial loading in the implant and in the screw but higher in abutment. In oblique loading, Model IH had lower stresses in the implant, but higher in the abutment and in the screw. In the σmax analysis for axial and oblique loads, stress peaks in Model IH were lower in PL, alveolar bone, and periimplant bone. In the σmin analysis for axial load, stress peaks in Model IH were lower in PL, but higher in alveolar bone and in periimplant bone. In oblique load, Model IH showed lower stress peaks in PL and alveolar bone, but higher stress peaks in periimplant bone. CONCLUSIONS: TISPs with IH implants do present lower risk of biomechanical failure.
PURPOSE: Biomechanical behavior of tooth-implant-supported prostheses (TISPs) with external and internal implants was compared. MATERIALS AND METHODS: Two 3-D models of TISP were designed by varying the implant: external (Model EH) and internal hexagons (Model IH). After loading, von Mises stresses were obtained in implants, abutments, and screws. Principal maximum (σmax) and minimum (σmin) stresses were analyzed in periodontal ligament (PL), alveolar bone, and periimplant bone. RESULTS: Model IH showed lower stress peaks in axial loading in the implant and in the screw but higher in abutment. In oblique loading, Model IH had lower stresses in the implant, but higher in the abutment and in the screw. In the σmax analysis for axial and oblique loads, stress peaks in Model IH were lower in PL, alveolar bone, and periimplant bone. In the σmin analysis for axial load, stress peaks in Model IH were lower in PL, but higher in alveolar bone and in periimplant bone. In oblique load, Model IH showed lower stress peaks in PL and alveolar bone, but higher stress peaks in periimplant bone. CONCLUSIONS: TISPs with IH implants do present lower risk of biomechanical failure.