Apical terminus location of root canal treatment procedures

The apical termination of root canal treatment is considered an important f actor in treatment success. The exact impact of termination is somewhat unc ertain; most publications on outcomes are based on retrospective findings. After vital pulpectomy, the best success rare has been reported when the pr ocedures terminated 2 to 3 mm short of the radiographic apex. With pulpal n ecrosis, bacteria and their byproducts, as well as infected dentinal debris may remain in the most epical portion of the canal; these irritants may je opardize apical healing. In these cases, better success was achieved when t he procedures terminated at or within 2 mm of the radiographic apex (0 to 2 mm). When the therapeutic procedures were shorter than 2 mm from or past t he radiographic apex, the success rate for infected canals was approximatel y 20% lower than that when the procedures terminated at 0 to 2 mm. Clinical determination of apical canal anatomy is difficult. An apical constriction is often absent. Based on biologic and clinical principles, instrumentatio n and obturation should not extend beyond the apical foramen.