Analysis of optimizing Bicon short implant placement in posterior mandible with type II bone

Dental implantation has emerged as the predominant approach for the replacement of missing teeth. Nevertheless, the resorption of alveolar bone occurs progressively following tooth loss, leading to varying perspectives regarding the application of bone augmentation techniques for standard-length implants versus the direct utilization of shorter implants. This study employs finite element analysis (FEA) to assess a typical Bicon short implant system, with the objective of determining the most effective implant for the posterior mandibular region with type II bone.

Eight three-dimensional finite element models were developed using three different diameters of Bicon implants (4.5 mm, 5 mm, and 6 mm) and three varying lengths (5 mm, 6 mm, and 8 mm). Each model comprised an implant-restoration system along with an alveolar bone block. Following the assembly of these components, vertical loads of 100 N and inclined loads of 50 N were applied to analyze the stress distribution within the implant-restoration system under both static and cyclic loading conditions.

Static analysis revealed that local stress increases within the Bicon implant-restoration system manifest at several critical interfaces. These included the contact zones between the bite force and the crown, the crown and the abutment, the abutment and the inner edge of the implant, as well as the outer edge of the implant and the alveolar bone. Furthermore, dynamic and fatigue analyses corroborated the stress distribution patterns observed in the static analysis across each abutment-implant complex. The highest concentration of stress was located beneath the hemispherical base of the abutment, extending to the interface between the abutment and the implant. Despite theoretically infinite cyclic loading, the overall fatigue safety factor (SF) was significantly reduced but did not fall below 1, indicating that the abutment-implant complex maintained its structural integrity. For the Bicon short implant utilized in type II bone within the mandibular posterior region, the optimal dimensions were determined to be 6 mm by 5 mm.

The results obtained from dynamic and fatigue testing can serve as both confirmation and complement of the outcomes derived from static load analysis in subsequent investigations, while the static assessments are commonly employed to identify critical regions where implant-restoration system may be prone to failure. Therefore, the design and clinical evaluation of implant-restoration systems should focus on these high-risk regions. Under specific conditions, Bicon short implants have the potential to attain a satisfactory service life in clinical applications.