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: Six models were constructed and divided into two groups. 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. Stress distributions under vertical and oblique loads of 100 N were analyzed.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 stress in the bone around the custom-made root-analogue implants in this study was lower than around traditional implants reported in the literature. Additionally, compared to the smooth group, the threaded group showed lower von Mises stress 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.