Bone remodeling of dental implant comparing between the customized titanium abutment and commercialized stock abutment and positioning of the implant placement depth: A 3D finite element analysis

Objective: Implant failure has been associated with the distribution of occlusal load and improper biomechanics of the dental implant. Although subcrestal implant placement has been shown to provide several benefits, there is still some disagreement when equicrestal implant placement is considered. Another factor were types of abutments: a prefabricated stock abutment with a standard cylindrical form, and a custom-made CAD/CAM abutment designed with individualized emergence profile and angulation to better adapt to the prosthetic requirements. This study aims to compare and analyze the stress distribution across implants components. Additionally, this study evaluates peri-implant bone remodeling in relation to implant placement depth and abutment design. Methods: Four models of different implant abutments and different implant placement depths (SAE: Commercialized stock abutment with equicrestal implant placement, SAS: Commercialized stock abutment with subcrestal implant placement, CAE: Customized titanium abutment with equicrestal implant placement and CAS: Customized titanium abutment with subcrestal implant placement) were analyzed using Finite element analysis (FEA). A 200 ​N force was loaded as a mechanical factor. The stress, strain, and strain energy density (SED) were calculated in 12 months of bone remodeling. Results: CAS and CAE had the greatest increase in cortical and cancellous bone density, respectively. CAS showed the greatest maximum von Mises stress at the cancellous bone, implant fixture, and screw, while SAS demonstrated the greatest maximum von Mises stress at abutment and crown. The maximum von Mises stress in the cortical bone were similar in all models. However, in the cancellous bone, SAS and CAS showed the values slightly exceeded the natural bony structure boundary. Conclusions: The implant placement depth had a more significant impact than abutment design. CAS exhibited the most rapid remodeling period in the first few months.