Finite element analysis of the junction between the regenerated bone adjacent to screw type implant and its surrounding native bone

Kim, Seong Ho; Kim, Su Gwan; Shim, Hyung Soon; Kim, Byung Ock

Abstract

Both loading on the implant itself and the transferred load to the bone have created an interest in biomechanical researches of oral implant. The purpose of this study was to investigate the stress gradients at the junction between the regenerated bone adjacent to screw type implant and its surrounding native bone using 3-dimensional finite element stress analysis method. The 4.1*11.5-mm implant (3 i, USA) was used for this study and was assumed to be 100% osseointegrated, and was placed in mandibular bone and restored with a cast gold crown. Using ANSYS software revision 7.0, a program was written to generate a model simulating a cylindrical block section of the mandible 20 mm in height and 10 mm in diameter. The present study used a fine grid model incorporating elements between 250,820 and 352,494 and nodal points between 47,978 and 67,471. Two loading situations were simulated at the central fossa: 200-N vertical loading and 200-N 30 degree lateral loading, respectively. For the quality of native bone adjacent to the regenerated type IV bone, the stresses in type I-native bone were higher compared to stresses in type III-native bone. Maximum stresses were generated at the junction between the regenerated bone and its surrounding native bone according to the increased depth of implant fixture. Stresses generated under vertical loading were higher than that under lateral loading. In summary, because stress concentrations can be also influenced by quality of the surrounding native bone, this have to be considered with care in making a treatment planning for implant supported prosthesis.