Biomechanics of the press-fit phenomenon in dental implantology: an image-based finite element analysis

In this work, a CT image-based approach, combined with the Finite Element Method (FEM), has been used to investigate the effect of the drill size on the biomechanics of the dental implant technique. A very accurate model of the human mandible bone segment has been created by processing high resolution micro-CT image data. The press-fit phenomenon has been simulated by FE analyses for different common drill diameters (DA？=？2.8？mm, DB？=？3.3？mm, and DC？=？3.8？mm) with depth L？=？12？mm. A virtual implant model has been assumed with a cylindrical geometry having height L？=？11？mm and diameter D？=？4？mm.The maximum stresses calculated for drill diameters DA, DB and DC have been 12.31？GPa, 7.74？GPa and 4.52？GPa, respectively. High strain values have been measured in the cortical area for the models of diameters DA and DB, while a uniform distribution has been observed for the model of diameter DC . The maximum logarithmic strains, calculated in nonlinear analyses, have been ？？=？2.46, 0.51 and 0.49 for the three models, respectively.This study introduces a very powerful, accurate and non-destructive methodology for investigating the effect of the drill size on the biomechanics of the dental implant technique.Further studies could aim at understanding how different drill shapes can determine the optimal press-fit condition with an equally distributed preload on both the cortical and trabecular structure around the implant.The use of dental implants has rapidly evolved since the advent of osseointegration, progressively replacing removable dentures in treatment of partially or completely edentulous patients. A fundamental pre-requisite for the clinical success in dental implant surgery is the fast and stable implant osseointegration.The press-fit technique, which is adopted to ensure a primary stability condition for endosseous implants, requires the diameter of the hole drilled within the jaw bone to be smaller than the implant major diameter. The bone tissues are affected by a