The purpose of this in vitro study was to evaluate the effect of various chelating solutions on the radicular push-out bond strength of calcium silicate-based and resin-based root canal sealers. Root canals of freshly-extracted single-rooted teeth (n = 80) were instrumented by using rotary instruments. The specimens were randomly divided into 4 groups according to the chelating solutions being tested: (1) 17% ethylenediaminetetraacetic acid (EDTA); (2) 9% etidronic acid; (3) 1% peracetic acid (PAA); and (4) distilled water (control). In each group, the roots were further assigned into 2 subgroups according to the sealer used: (1) an epoxy resin-based sealer (AH Plus) and (2) a calcium silicate-based sealer (iRoot SP). Four 1 mm-thick sections were obtained from the coronal aspect of each root (n = 40 slices/group). Push-out bond strength test was performed at a crosshead speed of 1 mm/min., and the bond strength data were analyzed statistically with two-way analysis of variance (ANOVA) with Bonferroni's post hoc test (p < 0.05). Failure modes were assessed quantitatively under a stereomicroscope. Irrespective of the irrigation regimens, iRoot SP exhibited significantly higher push-out bond strength values than AH Plus (p < 0.05). For both the sealers, the use of chelating solutions increased the bond strength, but to levels that were not significantly greater than their respective controls (p > 0.05). iRoot SP showed higher resistance to dislocation than AH Plus. Final irrigation with 17% EDTA, 9% Etidronic acid, and 1% PAA did not improve the bond strength of AH Plus and iRoot SP to radicular dentin.

No abstract

No abstract

--Careful examination of radiographs and the internal anatomy of teeth is essential.-- The location and morphology of root canals should be identified at high magnification under the microscope.

No abstract

No abstract

Background/purpose: The aim of this study was to determine and compare the fracture resistance of endodontically treated teeth restored with or without posts. Materials and methods: Undamaged, extracted human premolar teeth (48 in total) were randomly divided into four groups of 12 each. Clinical crowns of the teeth were cut 3 mm coronal to the cementoenamel junction. Root canals were enlarged using rotary canal instruments (Dentsply) and filled with gutta-percha (Dentsply) as well as a sealer (AH 26, De Trey). In all groups, gutta-percha was removed, and the post space was prepared using tapered drills (FRC Postec post kit, Ivoclar Vivadent). The first group of fiber-reinforced composite posts (FRC Postec Plus, Ivoclar Vivadent) and the second group of Ever Stick posts (Stick Tech) were luted into the root canals using dual curing resin cement (Variolink II, Ivoclar Vivadent). In the third group, post spaces were filled using a hybrid resin composite (Tetric Evo Ceram, Ivoclar Vivadent). The fourth group served as a control with direct resin composite core reconstruction formed without a post. Composite cores were constructed with a hybrid resin composite (Tetric Evo Ceram, Ivoclar Vivadent) in all groups. Fracture loading was accomplished using an universal testing machine at a crosshead speed of 1 mm/min in compression mode. Results: There were no statistically significant differences between the fracture resistance values for the four experimental groups (P > 0.05). Conclusions: Fiber-reinforced posts can be used as a core material in endodontically treated teeth as well as composite core reconstructions.

No abstract