Within the limitations of this in vitro study, the following conclusions could be drawn:

Implant design, superstructure material, and load direction significantly affect peri-implant microstrains.

The recorded compressive and tensile microstrains for the tested designs were within the physiologic loading range, as they did not exceed the compressive or tensile strength of the bone-implant interface, which is more than 3000 microstrains except for the standard sized implant supporting Lava Ultimate crowns under both loading directions.

Off-axial loading leads to uneven distribution of loads, in standard diameter implant, due to the cantilever effect, which caused microstrain values exceeding the physiologic limit, thus causing clinical failure over time.

Use of splinted double mini implants and short-wide implant to restore missing mandibular molar reduces cantilever effect which leads to lowering of peri-implant microstrains under off-axial loading.

Usage of full-metal crown implant superstructure reduces the peri-implant microstrain values compared to using Lava Ultimate crowns.