Screw Loosening

Screw loosening is a prosthetic complication whereby a screw loses its preload causing the loosening of a restoration or abutment. Due to the many forces exerted on a screw in an implant, a variety of issues may occur that contribute to screw loosening. These forces include the bite angle of the patient, loading of the implant, and the functional tension, rotation, and force on the screw. There are other factors that can contribute to the loosening of an implant or abutment screw as well. Some of these factors include the design of the implant, the design of the abutment, the amount of torque used to secure the screw, the efficiency of the implant’s manufactured parts, and the fit of the implant. While manufacturer errors may not be something the dental professional can control, they should follow all protocols when placing the implant and the screw to avoid improper torque, positioning, or incorrect loading.