Figure 7.

Distribution of location of broken PTU F1 in area away from the apical foramen. Note: “0 to 1.5 mm” refers to the broken PTU F1 located at area 0 to 1.5 mm from the apical foramen of the module, which is equivalent to 80% to 100% of complete root canal preparation. By inference, “1.5 to 3 mm” is equivalent to 60% to 80% of the complete root canal preparation, “3 to 5.5 mm” is equivalent to 40% to 60% of complete root canal preparation, “5.5 to 8 mm” is equivalent to 20% to 40% of complete root canal preparation, “8 to 10 mm” is equivalent to 0% to 20% of complete root canal preparation, respectively.