Study On The Structure Design Of Porous Dental Implants Based On SLM Technology

Lack of teeth can cause the patient to chew and pronunciation disorders,but also affect the appearance.The implant repair technique solves the problem well and restores the occlusal force close to the natural tooth.However,the elastic modulus of common implant teeth is much higher than that of human bone tissue,shorten the life of implant.The porous structure not only reduces the weight,decreases the elastic modulus of the implant,but also increases the contact area of the bone tissue to short the healing time,but the porous structure is difficult to process and the implant strength is reduced.In this study,a three-section porous structure implant was proposed firstBy constructing a porous structure implant to solve the problems of stress shielding and long operation time,ensure that the structure strength meets the requirements and manufactured easily.The structure of the implant was determined by topological optimization.The effect of the pore size,pore shape,location distribution and the design of the hollow structure on the strength of the implant was analyzed by finite element method.The implant with small and non-concentrated stress was manufactured.By tensile test,bending test,and compression test,the strength and elastic modulus of the porous structure at the end of the implant were verified.The results were further verified by strain test and in vitro biological experiments.The structure design of three-section porous dental implants with 400-micron square cross-arranged,which with end holes,middle threads and solid neck was made by SLM technology finally.The strength of the implants met the requirements and the elastic modulus was much lower than that of the traditional solid titanium alloy dental implants.Porous segment design can increase the strain value of implant-bone interface,and is more conducive to bone tissue growth in the range of bone reconstruction threshold.Simulated body fluid method further showed that the new dental implants made by SLM had certain bioactivity,and the bioactivity of the new dental implants could be enhanced by surface modification.However,the designed implant has lower porosity and less hydroxyapatite derived from in vitro biological experiments.The three-stage porous dental implants can not only satisfy the strength but also reduce the elastic modulus,which provides a broader space for bone tissue growth.Porous structure design is the inevitable trend of future development.A new idea of multi-stage design for implant structure is proposed.In this study,a three-section porous dental implant was designed.The stress-free area at the end of the implant was designed as a porous structure,which could not only promote the growth of bone tissue,but also further ensure the strength of the implant.And the end porous can be customized according to the patient’s bone requirements,However,fatigue tests,in vitro cell culture and animal experiments need to validate the Advantages of implant further.