What force direction has the LEAST concern regarding implant failure?

Correct answer: D. Vertical (axial) forces

• A. Horizontal (lateral) forces create bending moments at the implant-bone interface and are highly damaging — they concentrate stress at the crestal bone, leading to bone loss.
• B. Torsional forces can loosen the prosthetic screw and stress the implant body.
• C. Oblique forces have a significant lateral component and are the most common cause of implant complications in clinical settings.
• D. Correct. Vertical (axial) forces directed along the long axis of the implant are the best tolerated. Implants (like natural teeth) are designed to resist axial loading. Vertical forces are distributed along the implant-bone interface uniformly.