Evaluation of the effectiveness of a technique to prevent screw loosening

Statement of problem. Abutment screw loosening of single and multiple fixed partial dentures attached to external hexagonal implants is commonly encountered. Purpose. A technique that has been reported to prevent abutment screw loosening was tested with cyclic loading to determine its effectiveness. Material and methods. A sample using identical components and test protocol, with the abutment screw tightened to 20 Ncm, was used as control. Results. On the basis of the data obtained, the recommended technique does not increase resistance to screw loosening. The control sample sustained a mean number of cycles to screw loosening of more than twice that of the technique evaluated.