Modelling and simulation of bone grafting in dental prosthesis using fixation miniscrew under the effect of impact

Bone grafting is a surgical procedure that replaces missing bone with material from patient′s own body an artificial or natural substitute. Bone grafting is possible because bone tissue has the ability to regenerate completely if provided the space into which it has to grow. As natural bone grows, it generally replaces the graft material completely, resulting in a fully integrated region of new bone. The goal of this study was to analyze and compare the stress and strain distribution between the fully threaded and partially threaded screws fixation in the bone grafting. For this study, the stress field was evaluated numerically by three-dimensional finite element method using the Abaqus calculation code. An autogenous bone graft was used in an area where there is insufficient bone volume to ensure good anchoring of the implant in the jawbone. This bone block is tightened with screws of different thread length. The impact simulates a mechanical shock exerted on the bone graft and on the bone following a punch or accident of the patient. This is the originality of this work. Different bone grafting modalities can be proposed to increase the height of the available bone or its width, in one or more sectors for the placement of dental implants. The bone graft is fixed by different shapes screws in the case of blocks. The most important von Mises stresses are due to the impact of a projectile at an angle of + 30 ° and also by the shape of the screw. The maximum stress intensity of the fully threaded screw remains relatively low compared to the fully threaded screw is 77 %. This decrease in stress is probably due to the decrease in the number of threads in the screw. the highest stress level is in the middle of the first screw (01) and this is probably due to the bending of the latter under the effect of oblique and horizontal loads. The two screws 2 and 3 behave practically in the same way, they are in compression and the maximum stresses are located at the level of the first thread of the screw.