This study was performed to assess the radiopacity of a variety of canal filling and retrograde root-end filling materials according to the specification concerning root canal obturation materials.

Ten materials including Gutta-percha pellets, amalgam, Fuji II LC, Dyract® AP, Super EBA®, IRM®, AH 26®, Sealapex™, Tubli-Seal™ and dentin were evaluated in this study. In the first part, densitometric reading of an each step of aluminum step wedge on occlusal film were performed at 60 kVp (0.2, 0.3, 0.4 s), 70 kVp (0.2, 0.3, 0.33 s) to decide appropriate voltage and exposure time. In the second part, ten specimens which are 5 mm in diameter and 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 mm in thickness, were fabricated from each material studied. The specimens were radiographed simultaneously with an aluminum step wedge under decided condition (60 kVp, 0.2 s). The mean radiographic density values of the materials were transformed into radiopacity expressed equivalent thickness of aluminum (mm Al).

The following results were obtained.

Among the various conditions including 0.2 s, 0.3 s, 0.4 s at 60 kVp and 0.2 s, 0.3 s, 0.33 s at 70 kVp, the appropriate voltage and exposure time that meet the requirement of density from 0.5 to 2.0 was 0.2 s at 60 kVp.

It suggests that all experimental canal filling and retrograde root-end filling materials have a sufficient radiopacity that meet the requirement concerning root canal obturation materials except for Fuji II LC and Dyract.

The purpose of this study was to evaluate whether intracanal irrigation method could affect the adhesion between intracanal dentin and root canal filling materials (Gutta-percha/AH 26 sealer and Resilon/Epiphany sealer).

Thirty extracted human incisor teeth were prepared. Canals were irrigated with three different irrigation methods as a final rinse and obturated with two different canal filling materials (G groups : Gutta-percha/AH 26 sealer, R groups : Resilon/Epiphany sealer) respectively.

Group G1, R1 - irrigated with 5.25% NaOCl

Thirty obturated roots were horizontally sliced and push-out bond strength test was performed in the universal testing machine. After test, the failure patterns of the specimens were observed using Image-analyzing microscope.

The results were as follows.

Gutta-percha/AH 26 sealer groups had significantly higher push-out bond strength compared with the Resilon/Epiphany sealer groups (p < 0.05).