Effect of intracanal irrigants on the bond strength of epoxy resin-based and methacrylate resin-based sealers to root canal walls.

AIM: To assess the bond strength of Epiphany and AH Plus sealers to root canal walls using a push-out test after use of several endodontic irrigants. METHODOLOGY: Roots of 100 maxillary canines were sectioned horizontally 5 mm below the cemento-enamel junction to provide 4-mm-thick dentine disks that were embedded in acrylic resin and had their root canals prepared with a tapered bur (larger diameter=2.70 mm; smaller diameter=2.30 mm; length = 4 mm). The specimens were randomly assigned to five groups (n=20) according to the dentine surface treatment: I - 1% NaOCl (30 min); II - 1% NaOCl (30 min) + 17% EDTA (5 min); III - 17% EDTA (30 min); IV - 24% EDTA gel (30 min); V - 2% chlorhexidine gluconate (CHX) gel (30 min). In each group, two specimens were prepared for scanning electron microscopy to examine the surface of root canal dentine after use of each irrigant. The other 18 specimens were filled with AH plus (n = 9) or Epiphany (n=9) and subjected to a push-out test in an Instron machine. Data (in MPa) were subjected to statistical analysis by two-way anova and post-hoc Tukey-Kramer test (P < 0.05). RESULTS: AH Plus had a significantly higher bond strength (8.74 ± 2.75) than Epiphany (6.74 ± 3.97) (P < 0.05). One per cent NaOCl/17% EDTA was associated with significantly higher bond strength values (10.88 ± 3.05) than the other irrigants (P < 0.05). Seventeen per cent EDTA (8.75 ± 1.75), 24% EDTA gel (7.48 ± 3.48) and 2% CHX gel (7.89 ± 3.41) had intermediate values that were not significantly different from each other (P > 0.05). One per cent NaOCl was associated with the lowest mean values (3.70 ± 0.86) (P < 0.05). The interaction between surface treatment and sealer revealed significantly higher bond strength for 24% EDTA gel with AH Plus, 2% CHX gel with AH Plus and 1%NaOCl/17%EDTA with Epiphany (P < 0.05). CONCLUSION: Except for 1% NaOCl, the removal of smear layer with the other irrigants increased the bond strength of AH Plus to intracanal dentine. The use of 1% NaOCl for 30 min with 17% EDTA as final irrigant for 5 min increased the bond strength of Epiphany.

Radiopacity of root filling materials using digital radiography.

AIM: To evaluate radiopacity of root filling materials using digital radiography. METHODOLOGY: The sealers tested were AH Plus, Endofill, EndoREZ and Epiphany. Gutta-percha (Dentsply Maillefer) and Resilon cones were also tested. Acrylic plates, containing six wells, measuring 1 mm in depth and 5 mm in diameter, were prepared for the test, and filled with the materials. The test samples were radiographed together with an aluminium stepwedge calibrated in millimetres, according to ANSI/ADA Specification 57. For the radiographic exposures, digital imaging plates and an X-ray machine at 70 kVp and 8 mA were used. The object-to-focus distance was 30 cm, and the exposure time, 0.2 s. After the laser optic reading process, the software determined the radiopacity of the standardized areas, using grey-scale values, calculating the average radiographic density for each material. RESULTS: The decreasing values of radiopacity of the studied materials, expressed in millimetres of aluminium equivalent, were: Resilon (13.0), AH Plus(TM) (11.2), gutta-percha (9.8), Epiphany (8.0), Endofill (6.9) and EndoREZ (6.6). CONCLUSION: All materials had radiopacity values above 3 mm of aluminium recommended by ANSI/ADA Specification 57.

A comparative study of physicochemical properties of AH Plus and Epiphany root canal sealants.

AIM: To evaluate setting time, solubility and disintegration, flow, film thickness, and dimensional change following setting in a dual-cured resin root canal sealer Epiphany compared with an epoxy-resin-based sealer AH Plus. METHODOLOGY: The experiments were performed according to ANSI/ADA Specification 57 which tests the physicochemical properties of endodontic sealing materials. Five samples of each material were tested for each of the properties. In addition, deionized distilled water from the solubility test of Epiphany was submitted for analysis of the cations Fe, Ni, Ca, Mg, Zn, Na, and K in an atomic absorption spectrometer. Three samples were analysed. RESULTS: There were no statistical differences (P>0.05) in flow (AH Plus: 38.57 mm; Epiphany: 35.74 mm) and film thickness (AH Plus: 10.6 microm; Epiphany: 20.1 microm). The solubility (AH Plus: 0.21%; Epiphany: 3.41%) and dimensional alterations following setting (AH Plus: expansion of 1.3%; Epiphany: expansion of 8.1%) were statistically different (P<0.05). The setting times of both sealants were in accordance with ANSI/ADA requirements. CONCLUSIONS: Setting time, flow, and film thickness tests for both cements conformed to ANSI/ADA standards. Dimensional alteration test for both cements were greater than values considered acceptable by ANSI/ADA. Epiphany values regarding solubility were also greater than values considered acceptable by ANSI/ADA.

Dental anomaly: dens evaginatus (talon cusp).

Dens evaginatus is a developmental anomaly characterized by the occurrence of an extra cusp shaped as a tubercle projecting from the palatal or buccal surfaces (talon cusp). In the anterior dentition, dens evaginatus is more commonly found in the maxilla and on the palatal surface of the tooth. The authors present a case of dens evaginatus in a maxillary central incisor, in which the evagination was removed and routine endodontic treatment was performed.

In vitro study of the effect of aged eugenol on the flow, setting time and adhesion of Grossman root canal sealer.

In the present study, the effect of aged eugenol (up to 180 days) on the flow, setting time and adhesion of Grossman root canal sealer was evaluated, following the American Dental Association specification number 57 for root canal sealers. An Instron Universal testing machine 4444 was used for testing adhesion. There were statistically significant differences between groups, with a higher flow, lower setting time and adhesion for aged eugenol. It can be concluded that time affects eugenol, with consequent effects on Grossman sealer.