Anti-rotation Feature
An internal or external geometric element—such as a hex, octagon, or spline—on an implant-abutment connection that prevents rotational movement of the prosthetic component.
Full Definition
The anti-rotation feature is an engineering design incorporated into implant–abutment interfaces to resist rotational displacement of the abutment or restoration under occlusal forces. Common geometries include external hexagons, internal hexagons, internal octagons, conical morse-taper connections, and spline configurations. Loss of the anti-rotation feature leads to abutment rotation, screw loosening, and prosthetic complications. Editors should be aware that this term describes a design characteristic, not a separate component, and should avoid treating it as a synonym for the connection type itself.
Usage
Usage note: Do not use as a synonym for the implant–abutment connection type; specify the geometry (hex, octagon, spline, taper) where precision is required.
In Context
- "The fractured abutment screw was attributed to loss of the anti-rotation feature after repeated seating and removal cycles." — Complication case report
- "The author described the spline-type anti-rotation feature but had incorrectly labelled it as a 'locking mechanism' in three places, which the editor corrected." — Technical article copyedit