Authors: Tamse A, Katz A, Kurant M.
Title: The intentional instrument separation technique versus the silver cone method: a comparison of the apical seal.
Journal: Int Endod J
Date: Jul 1988
Citation: 21(4):268-72
Category: Obturation
Evidence-based Ranking: 5
Purpose/Objectives: To compare the apical dye leakage of extracted curved roots sealed with intentionally separated files with those sealed with silver cones.

Materials & Methods: 180 extracted teeth, using curved roots of maxillary and mandibular molars, were circumferentially filed to a size 25, patency confirmed, and filled with either a separated file with or without sealer or a silver cone with or without sealer. AH26 was used. The teeth were immersed in dye, cleared, and examined. Depth of penetration of dye was recorded.

Results: More than half of the silver cone + sealer group leaked 1mm or less. Using sealer, no cases leaked more than 6mm. 76.5% of all roots leaked up to 6mm. Silver cones + sealer leaked the least, the files without sealer leaked the most.

AuthorÂ’s Conclusion: Root canals obturated with silver cones and separated files without sealer leaked considerably more than those obturated with sealer. Canals sealed with silver cones or files with sealer showed similar amounts of leakage. In severely curved canals, intentionally separating files and using AH26 sealer could be used instead of silver cones as the filling material.

Validity of Conclusion: I think the results are not valid. The conclusion does not make sense from the results given.

ReviewerÂ’s Comments: When leakage occurs up to 6mm 76.5% of the time, the method of obturation is a failure. The results of this study support NOT using any of the mentioned techniques.