The Application Of Topology Optimization Method In The Simulation Of Cancellous Bone Structure Around Dental Implant

Biomechanics, which as a multiple disciplinary, includes biofluid mechanics,biosolid mechanics, sports biomechanics and so on. The study of bone mechanicsbelongs to biosolid mechanics. Traditional method is mechanical testing, but has somelimitations. With the development and updating of computer technology, the changesof trabecular bone structure can be numerically simulated, which can provide atheoretical basis for clinical practice, at the same time, reduce postoperative adversephenomenon. So, it has great significance and application value.Bone includes cancellous bone and cortical bone. Since cancellous bone hascomplex sturcture and small size, it’s difficult to study it. Wolff’s law states that boneadapts to the loads under which it is placed. If loading on a bone increases, it willremodel itself over time to become stronger to adapt to the loading. Topologyoptimization is a mathematical approach that optimizes material layout within a givendesign space, for a given set of loads and boundary conditions such that the resultinglayout meets a prescribed set of performance targets. Using topology optimization,engineers can find the best concept design that meets the design requirements.Nowadays, topology optimization method has been involved in many field ofengineering, such as structure design of aircraft, bridge, automobile, but it is rarelyapplied to the simulation of bone structure.In this paper, topology optimization method was introduced to biomechanics tosimulate the structures of exognathion and mandible. First of all, given uniformstructure and certain loading conditions, microstructures of cancellous bone weresimulated. Because the load conditions are very complex in human body, not onlytensile and compressive loads, but also shear load were considered. Further modelswere even exerted combined loading conditions. Comparisons between our resultsand the results from self optimization theory of bone were performed to verify if ourresults are correct. Then, comparisons between our results with CT images of real bone structure were performed to verify the feasibility of using topology optimizationmethod to simulate bone structures. Secondly, dental implant was added to the basicstructures, while the same load conditions were applied to simulate the structurechanges when there are implants in bone. After that, the results were used as the initialstructures to apply the loading conditions with the same magnitudes but differentangles to simulate the influence of loads, which can provide some references forclinical treatment. Then, the same loading condition, the same implant size, butdifferent implant materials were used to investigate the effects of different implantmaterials. Finally, changes of bone structure with different dental implant materialswere simulated, and differences of the exognathion density and stress distributionwere obtained, which may provide certain references to clinical practice.