July 30, 2015
Rod contouring with the use of a French bender reduced rod stiffness and rod yield strength in all types of rods, according to researchers’ findings.
The researchers analyzed the effects of rod contouring on rod strength and stiffness through a three-point bending test, during which, an 18-cm rod was loaded with a load applicator at a rate of 10 mm per minute. The researchers assessed rod diameters of 5.5 mm, 6 mm and 6.35 mm and two different material types (titanium alloy and cobalt-chromium [CoCr] alloy). Additionally, four different rod curvatures were evaluated: a no-preparation rod of 0° acting as the control, a 0° rod bent at one point to make 10° tangential angles and then bent back from the opposite side, a bent rod with 20° tangential angles, and a 40° bent rod. All of the rods were bent using a French bender.