To date, there are limited publications regarding the investigation of screw loosening according to abutment angulations and collar lengths before and after dynamic cyclic loading. Sethi and colleagues [19] noted no implant fractures or screw loosening during a 96-month monitoring period for 2261 implants (N = 467 patients) with angulations ranging from 0 to 45°. While Asvanund and colleagues [4] addressed screw loosening with increasing abutment angulations, Siadat and coworkers [9] concluded that increase in height of the abutment collar could adversely affect the torque loss of the abutment screw.

So, the aim of this in vitro study was to evaluate the effect of different angulations and collar lengths of the implant abutment on screw loosening by measuring removal torque value before and after dynamic cyclic loading using digital torque gauge.