Retightening of Internal Hexagonal and Conical Dental Abutment Connections: A FEA Analysis.

Understanding the impact of tightening and re-tightening on the abutment screw loosening of a dental implant This study used finite element methods to determine how various materials and abutment connections react to the retightening effect of the abutment screw when saliva or blood enters the space between the abutment and the dental implant. Internal hex and conical connection preload values are found to increase while the fluid at the interface of the abutment and dental implant decreases. Retightening: compared to the tightening of the abutment screw, the conical abutment connection preload value decreases by 3%. The tightening and retightening processes proved to have depended on the type of implant-abutment connection. Removal torque for abutment screws is observed at 0.27, 0.28, 0.29, 0.30, 0.31, and 0.32, and it is found that decreasing the abutment screw pitch can also be an effective method to increase resistance to screw loosening. The internal hex is proven to be the best abutment design for increasing the preload value and is recommended for clinical applications.