Comparison of Subperiosteal Implant Designs Applied to Atrophic and Edentulous Mandible Under Traumatic Forces: A Three-Dimensional Finite Element Analysis

Ilgın Arı, Gülin Acar, İpek Dilara Baş, Emre Tosun

Full text link: https://pubmed.ncbi.nlm.nih.gov/40376767/

Comparison of Subperiosteal Implant Designs Applied to Atrophic and Edentulous Mandible Under Traumatic Forces: A Three-Dimensional Finite Element Analysis

1. Scientific Reference

• Study title: Comparison of Subperiosteal Implant Designs Applied to Atrophic and Edentulous Mandible Under Traumatic Forces: A Three-Dimensional Finite Element Analysis
• Authors: Ilgın Arı, Gülin Acar, İpek Dilara Baş, Emre Tosun
• Journal: Journal of Oral Implantology
• Year of publication: 2025
• DOI: 10.1563/aaid-joi-D-25-00073
• PMID: 40376767

2. Scientific Background

Managing patients with a severely atrophic edentulous mandible remains one of the most demanding situations in implant dentistry and oral surgery. Extensive bone resorption may preclude the placement of conventional endosseous implants without additional reconstructive procedures. In this context, custom-made subperiosteal implants have re-emerged as a potential treatment alternative, supported by advances in digital planning, CAD/CAM technologies, and patient-specific manufacturing.

Although these implants are designed to match the patient’s anatomy, their biomechanical performance under exceptional loading conditions is an important consideration. Understanding how implant material and structural design influence stress transmission throughout the prosthetic components and mandibular bone may contribute to improving future implant concepts. This study explores these biomechanical aspects through computational simulation rather than clinical evaluation.

3. Study Objective

The purpose of this study was to compare the biomechanical behavior of four custom subperiosteal implant configurations designed for a severely atrophic edentulous mandible. Using three-dimensional finite element analysis, the investigators evaluated whether implant material (titanium versus polyetheretherketone [PEEK]) and framework design (one-piece versus two-piece) influenced stress distribution when subjected to a simulated traumatic load.

4. Methodology

This investigation was conducted as a preclinical finite element analysis (FEA). A digital model representing a severely atrophic edentulous mandible was reconstructed and treated using four different subperiosteal implant configurations. Two models incorporated PEEK implants, including one-piece and two-piece designs, while the remaining two models employed equivalent titanium frameworks.

Each implant was secured to the mandibular model with fourteen osteosynthesis screws positioned along the mandibular tension lines. A traumatic force of 2,000 N was applied to the mandibular prosthesis in an anteroposterior direction. The investigators measured maximum principal stress (Pmax), minimum principal stress (Pmin), and Von Mises stress values. No patient population, clinical follow-up, or biological outcomes were included in the available abstract.

5. Main Findings

The simulations demonstrated that both implant material and structural configuration influenced biomechanical stress distribution.

The one-piece titanium implant generated the highest maximum principal stress within the symphyseal region, reaching 45.888 MPa, whereas the remaining models showed relatively similar values in this area. At the mandibular condyle, the highest maximum principal stress was observed with the two-piece PEEK design (941.338 MPa), while the lowest value occurred in the one-piece titanium model (905.756 MPa).

Von Mises stress analysis revealed lower and more consistent stress values on the prosthetic abutments and abutment screws in the PEEK models compared with the titanium designs. Conversely, the titanium implant frameworks themselves experienced lower internal Von Mises stresses than the corresponding PEEK frameworks.

Based on these simulations, the authors concluded that the one-piece PEEK subperiosteal implant exhibited the most favorable mechanical behavior regarding mandibular fracture risk under the traumatic loading conditions evaluated.

6. Clinical Analysis

This study provides valuable biomechanical insight into modern patient-specific subperiosteal implant designs rather than direct clinical evidence. Its findings suggest that implant material influences not only the stresses experienced by the implant framework itself but also the way mechanical loads are transferred to prosthetic components and surrounding mandibular structures.

The comparison illustrates a mechanical trade-off between rigidity and stress dissipation. Titanium frameworks appeared to withstand lower internal mechanical stresses, whereas PEEK reduced stress concentrations affecting the abutments and fixation screws. Within the specific computational model used, the one-piece PEEK design demonstrated the most favorable stress distribution in relation to simulated mandibular fracture risk.

These findings should be interpreted cautiously. Finite element analysis represents an established engineering tool for investigating biomechanical behavior, but it cannot reproduce biological responses such as bone remodeling, osseointegration, tissue healing, patient variability, or long-term functional loading. Consequently, these numerical results should be viewed as hypothesis-generating data that may inform implant design rather than as evidence supporting the clinical superiority of one material or configuration.

7. Clinical Applications

The results may be relevant for clinicians managing patients with severe mandibular atrophy in whom conventional implant placement is challenging or would otherwise require extensive bone augmentation procedures.

The study suggests that PEEK-based subperiosteal implants could represent a promising direction for future patient-specific implant rehabilitation. In addition, the authors indicate that two-piece implant designs may provide greater flexibility during implant fabrication and clinical application. These potential advantages, however, require confirmation through prospective clinical investigations before influencing routine treatment protocols.

8. Level of Evidence, Limitations and Transparency

This publication represents a preclinical computational investigation based on three-dimensional finite element analysis. Accordingly, its level of evidence is lower than that provided by prospective clinical studies or randomized controlled trials.

The principal limitation is inherent to the study design itself. The findings originate from a numerical simulation performed under predefined loading conditions and therefore cannot predict clinical implant survival, biological complications, patient-reported outcomes, or long-term treatment success.

No information regarding funding sources or conflicts of interest is reported in the abstract provided. Likewise, additional methodological limitations are not specifically discussed in the available data.

9. Key Study Highlights

• Study type: Preclinical three-dimensional finite element analysis.
• Level of evidence: Preclinical computational study.
• Study model: Digital model of a severely atrophic edentulous mandible.
• Number of patients: Not specified in the available information.
• Number of implants evaluated: Four subperiosteal implant configurations.
• Follow-up period: Not applicable.
• Primary outcome: Distribution of maximum principal stress, minimum principal stress, and Von Mises stress under a simulated 2,000 N traumatic load.
• Main finding: The one-piece PEEK subperiosteal implant demonstrated the most favorable biomechanical performance regarding simulated mandibular fracture risk.
• Scientific conclusion: Implant material and framework design influence biomechanical stress distribution, with PEEK and two-piece configurations offering distinct mechanical characteristics.
• Study limitations: Computational model only; no clinical validation or long-term biological assessment.

10. Scientific Impact

This study contributes to the growing body of research investigating customized subperiosteal implants for complex implant rehabilitation. By comparing both implant material and structural design within the same finite element model, it provides new biomechanical data that may guide future engineering developments in patient-specific implant systems.

Rather than establishing clinical recommendations, the investigation improves understanding of how different implant configurations distribute traumatic forces throughout the prosthetic assembly and mandibular framework. These observations may support future optimization of custom implant design and encourage subsequent experimental and clinical studies aimed at determining whether the simulated mechanical advantages translate into meaningful clinical benefits for patients with severe mandibular atrophy.

11. Editorial Conclusion

This finite element analysis offers an important biomechanical perspective on contemporary subperiosteal implant design for severely atrophic edentulous mandibles. Under the simulated traumatic conditions investigated, the one-piece PEEK configuration demonstrated the most favorable stress distribution with respect to mandibular fracture risk, while two-piece designs offered additional design flexibility. As these findings are based exclusively on computational modeling, clinical validation remains essential before they can influence evidence-based implant treatment strategies.