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In Vitro Study To Analyze Reverse Torque Values Of Prosthetic Screws With Multiple Loosening/Tightening Preload Cycles, Amira Alhameed

Master's Theses (2009 -)

Purpose: To determine the number of loosening/tightening preload cycles prosthetic retaining screws can withstand before fracture, and to record the reverse torque values on each of the 10 applications of screw tightening and loosening. Materials and methods: The testing assemblies consisted of 30 temporary cylinder/multiunit abutment/internal connection implants, 10 each from Biohorizons, Zimmer Biomet Dental, and Dentsply Sirona Astra; the specimens were inserted into resin blocks. Temporary cylinders were connected to the abutments with new prosthetic screws and torqued to the appropriate preloads. The first tests of repeated tightening/loosening preload cycles were applied using a Digital ® torque gauge instrument …