Dentinal Tubule Penetration and Retreatability of a Calcium Silicate-based Sealer Tested in Bulk or with Different Main Core Material

Introduction: The aim of this study was 2-fold: to evaluate the penetration of a tricalcium silicate based endodontic sealer (EndoSequence BC Sealer; Brasseler USA, Savannah, GA) into dentinal tubules without a core material (sealer) or with .02 or .04 tapered bioceramic gutta-percha points and to compare the time required to remove the root fillings. Methods: Roots of extracted human mandibular incisors (N = 60) were prepared with 0.04 taper nickel-titanium rotary files to #35 and randomly assigned into 3 groups (n = 10/group) according to the obturation method used: 1. obturating with sealer only, 2. sealer +.02 point, and 3. sealer +.04 point. The sealer was labeled with rhodamine B for analyzing dentinal tubule penetration under a confocal laser scanning microscope. The remaining specimens (n = 30) were used to measure the time for removal of the root canal fillings with retreatment files. The data were analyzed using 1-way analysis of variance and post hoc Games-Howell tests for dentinal tubule penetration and the Kruskal-Wallis test for retreatment time. Results: Significantly greater sealer penetration and sealer-penetrated area was achieved when the sealer was used with a.04 gutta point (P <.05), whereas there was no difference between the sealer and.02 gutta point groups (P >.05). All test groups showed a similar depth of sealer penetration (P >.05). Groups with the gutta-percha points required a similar time to remove root filling (P >.05), whereas the working length could not be achieved in the sealer group. Conclusions: The use of a matched-taper bioceramic gutta-percha point enhanced the dentinal tubule penetration of the tested tricalcium silicate based sealer. The use of a core material in conjunction with sealer facilitates removal of the root filling to the working length.