Submodelling approach to screw‐to‐bone interaction in additively manufactured subperiosteal implant structures

Abstract

Thanks to new digital technologies, complex cases of severe maxillary atrophy may now be treated with additively manufactured subperiosteal implant structures (AMSISs). However, there are few studies addressing this topic and most of them focus on the mechanical behaviour of the AMSIS itself without considering its interaction with the maxilla bone. The aim of this study is to provide a methodology based on finite element analysis (FEA) to evaluate the effect of interaction between the maxilla bone and the screws fixing the AMSIS. The mechanical performance of an AMSIS was examined via a FEA based on submodelling. Significant differences were encountered in displacements and reaction forces when bone–screw interaction was considered. Stress in the cortical layer was found to be close to the maximum strength while the trabecular layer seems to have no effect on the results; stresses in the AMSIS are lower than the fatigue stress limit. Finally, the comparison of stresses between models with and without osseointegration shows how stresses drop once osseointegration is complete. The proposed submodelling approach considerably reduces the computational effort and enables both a detailed model of the interaction between the thread of the screws and the bone and an accurate evaluation of displacement and stress fields on the interface. The results have shown that stresses in the cortical bone are highly affected by the initial geometry of the thread inside the bone, which demonstrates the importance of modelling the effect of the thread.

Exceptional Cases Demand Exceptional Personalized Solutions: The Next Level in Dental Rehabilitation

“…Apart from the design features, rigid and far-away fixation from the transition zone of the posts through the soft tissue into the oral cavity is not shown in the literature either [ 19 , 20 ]. Many cases are published in which the amount of metal close to the transition zone through the soft tissue is too high, the extension of the footplate is too small, the number of screws is too low and the position of the screws is too close to the posts [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. Evaluation of patient satisfaction after dental rehabilitation using modern sub-periosteal CAD/CAM implants in severe cases shows that this less invasive technique has a high acceptance [ 30 , 31 ].…”

Clinical performance of additively manufactured subperiosteal implants: a systematic review

“…They present several advantages over traditional casted ones. Better biocompatibility, one-time surgery possibility, a reduction in total mass of the material used, optimization of arms and fixation screws dimensions and number (thus reducing costs and avoiding micromovements) or time of surgery reduction (ensuring a better fitting and avoiding time to re-adapt bone), can be cited among the improvements [ 13 – 15 ]. New finite element method analysis on additively manufactured SI are desirable, to further enhance this advantages and also could be helpful to prevent overextending the implant.…”

Peculiarities of biomaterials transplantation and implantation of titanium implants in atrophy of hard and soft tissues of the jaws

“…Полученные данные подтверждали целесообразность трансплантации ксеногенных биоматериалов, особенно при значительной атрофии альвеолярного отростка верхней челюсти (вплоть до 2,0 мм). Наличие прочного каркаса более всего необходимо для устойчивости имплантата в подобных случаях [ 31,32 ] . Проведенные нами исследования подтвердили указанные преимущества трансплантации ксеногенных биоматериалов.…”