... reference point than minor diameter because the minor reference point is more difficult to locate (Martinez-Lozano, et al., 2 001; Lee, et al., 2 002) . Lee, et al., (2 002) recommended using ... characteristic allows the instrument to experience a rotational phenomenon known as precession or swagger (Scianamblo, 2011 ). The benefits of this design characteristic include: • It further ... is done according to the previously mentioned protocol using a size 30 /02, 40 /02, or 50 /02 NiTi instruments. The 30 /02 instrument was fitting snugly at working length in the palatal root...