Evaluation of torque removal in abutment submitted to cyclic test

Objective: The objective of the study was to evaluate the torque removal necessary to remove the prosthetic abutment screw of implants with external and internal hexagon after cyclic loading tests. Methods: Twenty samples were made using implants (ten internal hexagons and ten external hexagons) perpendicular set in acrylic resin bases. The prosthetic abutments, specific to each group, were united to the implants by their respective retention screw with load of 30N, controlled with a torque gauge. Each sample was immersed in distilled water at 37 ° C, supported on a base with 45° inclination and then submitted to cyclic loading test, under constant 50N axial load, frequency of 2Hz and 50,000 cycles. After cycling, the screws were removed with digital torque gauge and the results were registered. Results: The data were submitted to the “t” test (Student). The result shows significant statistically differences in relation to the loss of torque after cyclic loading test of all abutments (average of 27.5% internal hexagon and 48% to external hexagon). Conclusion: The torque removal after cyclic loading is lower than the initial torque, regardless of the connection type. Implants with internal hexagon resisted better to the cyclic loading test, in relation to the loss of torque, than the external ones.