Clinical Outcomes of Root-Analogue Implants Restored with Single Crowns or Fixed Dental Prostheses: A Retrospective Case Series

et al. 2021

Preprint

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.

Section: Introductionmentioning

confidence: 99%

“…Although many researchers had reported many successful clinical cases using RAIs in the past years [6,9], there have been some failures [8,10]. Research has shown that stress distribution in the bone around implants under loading is related to the success of implantation [11].…”

Section: Introductionmentioning

confidence: 99%

Influence of Sagittal Root Positions on the Stress Distribution Around Custom-made Root-analogue Implants: A Three-dimensional Finite Element Analysis

et al. 2021

Preprint

“…Since then, many researchers have reported the successful use of RAIs in clinical cases [11,15,16]. However, there have also been some cases of failure [17,18]. Evans et al [10] found that the main reason for RAI failure was pressure-induced resorption or fracture of the thin buccal wall of the alveolar bone.…”

Section: Introductionmentioning

confidence: 99%

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

European J Oral Sciences

et al. 2022

This study was designed to investigate the influence of diameter reductions on the stress distribution around root-analogue implants via 3D finite element analysis. Four root-analogue implant models with different diameter reductions (0, 1, 2, or 3 mm), a traditional threaded implant and congruent bone models were created through reverse engineering. A 100-N force was applied parallel with and in a 45˚angle to the implant axis, respectively. The stress concentration in the labial neck area around implants with 1-2 mm diameter reduction was lower than seen with no reduction. When the implant diameter was reduced by 3 mm, there were obvious stress concentrations in both implant and bone (the maximum stress was 206 and 111 MPa, respectively). In other groups, the maximum stress was 65.1 MPa in the bone and 108 MPa in the implant. Additionally, the stress concentration in the bone around the root-analogue implant when the implant diameter was reduced by 0-2 mm (maximum stress of 65.1 MPa) was obviously smaller than that around the traditional implant (maximum stress 130.4 MPa). Reducing the diameter of maxillary central incisor root-analogue implants by up to 2 mm next to the labial cortical bone could help disperse stress.

“…Although many researchers had reported many successful clinical cases using RAIs in the past years [ 6 , 9 ], there have been some failures [ 8 , 10 ]. Research has shown that stress distribution in the bone around implants under loading is related to the success of implantation [ 11 ].…”

Section: Introductionmentioning

confidence: 99%

“…RAIs are defined as implants that have the same contour as the extracted root [2,3]. Compared to traditional implants, RAIs have some advantages, such as a better fit in the extraction socket, eliminating the need for conventionally used bone drills and other traumatic procedures that are required to prepare for implantation, as well as uncomplicated immediate implant placement, increased patient comfort, and better aesthetic effectiveness through immediate temporary restoration [1,[4][5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2021

BMC Oral Health

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.