Effect of Different Applied Torque Maintenance Times on Detorque Values of Abutment Screws in Single Implant-Supported Fixed Prostheses

We evaluated the effect of maintaining the applied torque for one minute on the reverse torque value (RTV) as compared to immediate torque application and retorquing after 10 minutes. A total of 48 screws were used to torque the abutment utilizing three different protocols (A-C); immediate torque application to the recommended 35 Ncm, torque applied to the recommended 35 Ncm, followed by retorquing of the same screw after 10 minutes and abutment screws were torqued to the recommended 35 Ncm, and the torque was held for one minute. The gap size between the implant and supra-structure was measured at three fixed points for each surface. Data were analyzed using SPSS software (alpha = 0.05). The mean RTV for 1 minute, immediate, and 10 minutes was 32.68 +/- 2.04 Ncm, 32.5 +/- 0.93 Ncm, and 30.54 +/- 0.90 Ncm, respectively. The difference between RTV in the 1-min and 10-min protocols was significant (P < 0.05). Pearson's coefficient demonstrated a negative correlation between RTV and the gap between the supra-structure and the implant interface (r =-0-43, P < 0.01). When tightening abutment screws of implant-supported single crowns, holding the applied torque for 1 minute has proven to be efficient. Furthermore, larger gap values between the supra-structure and the implant inversely affect RTV, forcing the clinician to take caution to have a well-fitted supra-structure with as minimal a gap as possible.