Wear promoted in the apical third of simulated canals after instrumentation with ProTaper universal system.

Objective: This study evaluated the wear in the apical third of simulate canals after preparation with ProTaper Universal Rotary System.

Material And Methods: 24 sets of instruments were used in 24 simulated canals in transparent epoxy resin blocks with degree of curvature of either 20 degrees or 40 degrees. The canals were photographed preoperatively and after preparation of the apical stop with ProTaper F3, F4 and F5 instruments.