Influence of sagittal root positions on the stress distribution around custom-made root-analogue implants: a three-dimensional finite element analysis

Abstract

Background Stress concentration may cause bone resorption even lead to the failure of implantation. This study was designed to investigate whether a certain sagittal root position could cause stress concentration around maxillary anterior custom-made root-analogue implants via three-dimensional finite element analysis. Methods The von Mises stresses in the bone around implants in different groups were compared by finite element analysis. Six models were constructed and divided into two groups through Geomagic Studio 2012 software. The smooth group included models of unthreaded custom-made implants in Class I, II or III sagittal root positions. The threaded group included models of reverse buttress-threaded implants in the three positions. The von Mises stress distributions and the range of the stresses under vertical and oblique loads of 100 N were analyzed through ANSYS 16.0 software. Results Stress concentrations around the labial lamella area were more prominent in the Class I position than in the Class II and Class III positions under oblique loading. Under vertical loading, the most obvious stress concentration areas were the labial lamella and palatal apical areas in the Class I and Class III positions, respectively. Stress was relatively distributed in the labial and palatal lamellae in the Class II position. The maximum von Mises stresses in the bone around the custom-made root-analogue implants in this study were lower than around traditional implants reported in the literature. The maximum von Mises stresses in this study were all less than 25 MPa in cortical bone and less than 6 MPa in cancellous bone. Additionally, compared to the smooth group, the threaded group showed lower von Mises stress concentration in the bone around the implants. Conclusions The sagittal root position affected the von Mises stress distribution around custom-made root-analogue implants. There was no certain sagittal root position that could cause excessive stress concentration around the custom-made root-analogue implants. Among the three sagittal root positions, the Class II position would be the most appropriate site for custom-made root-analogue implants.

Influence of different diameter reductions in the labial neck region on the stress distribution around custom‐made root‐analogue implants

“…The method used in this study is similar to that used in our previous study [30], and the specific process of the FEA is briefly outlined in the following.…”

Success Factors of Additive Manufactured Root Analogue Implants

“…Most of RAIs in existing case reports were placed in the socket under finger pressure without details on planning and positioning. 21,22,153 Since the RAI has a similar shape as the natural tooth, it can be implanted along the extraction socket, 194 and further research is needed on the details.…”

“…(d) Different sagittal root positions for RAI. Reproduced with permission from ref . Copyright 2021 Springer Nature.…”

“…Few studies have focused on RAI positioning criterion. As shown in Figure d, Lin et al reported the influence of the position of the RAI root on the stress distribution by the FE method and concluded that the class II was more appropriate. Most of RAIs in existing case reports were placed in the socket under finger pressure without details on planning and positioning. ,, Since the RAI has a similar shape as the natural tooth, it can be implanted along the extraction socket, and further research is needed on the details.…”

“…As shown in Figure d, Lin et al reported the influence of the position of the RAI root on the stress distribution by the FE method and concluded that the class II was more appropriate. Most of RAIs in existing case reports were placed in the socket under finger pressure without details on planning and positioning. ,, Since the RAI has a similar shape as the natural tooth, it can be implanted along the extraction socket, and further research is needed on the details.…”