Li R, Wu Z, Chen S et al. Biomechanical behaviour analysis of four types of short implants with different placement depths using the finite element method. J Prosthet Dent 2023; DOI: 10.1016/j.prosdent.2023.01.005. Online ahead of print.

Large implant diameters, rather than long implants, led to reduced intraosseous strain, especially under oblique loading.

This finite element analysis study evaluated the microstrain-stress distribution in the peri-implant bone and implant components for 4 types of short implants at different placement depths of platform switching. By using short implants as prototypes, 4 short implant models were 1:1 modelled. The diameter and length of the implants were 5×5, 5×6, 6×5 and 6×6 mm. The restoration was identical for all. Three different depths of implant platform switching were set: equicrestal, 0.5-mm subcrestal and 1-mm subcrestal. The models were then assembled and assigned an occlusal force of 200 N. A finite element analysis was completed. The 5×5 implant group showed the largest intraosseous strain. A 1-mm increase in implant diameter resulted in a 17% to 37% reduction in maximum intraosseous strain when loaded with oblique forces. The strain in the bone tended to be much smaller than the placement depth at the equicrestal and 0.5-mm subcrestal positions than that at the 1-mm subcrestal position.