5Coutinho Filho T, La Cerda RS, Gurgel Filho ED, et al. The influence of the Surgical Operating Microscope in locating the mesiolingual canal orifice: a laboratory analysis. Braz Oral Res, 2006,20(1):59-63.
6Rampado ME, Tjaderhane L, Friedman S, et al. The benefit of the operating microscope for access cavity preparation by undergraduate students. J Endod, 2004,30(12):863-867.
7Buhrley LJ, Barrows M J, BeGole EA, et al. Effect of magnification on locating the MB2 canal in maxillary molars. J Endod, 2002,28(4):324-327.
8Zillich R, Dowson J. Root canal morphology of mandibular tirst and second premolars. Oral Surg Oral Med Oral Pathol, 1973,36 (5):738-744.
10[1]Ingle JI, Newton CW, West JD, et al. Obturation of the radicularspace.In: Ingle JI, Bakland LK. Endodontics. 5th ed. Hamilton, Ontario: BC Decker Inc. 2002. 645-649