IADR Abstract Archives
Digital Radiographic Survey of Endodontic Sealers
Objectives: International standards for radiopacity have required film radiography until 2014. Our objective was to compare a variety of endodontic sealers using the new ISO13116 method for digital radiography, and make comparisons to past reports using film radiography.
Methods: Twenty-one endodontic sealers and three root-end fillers were compared using the ISO13116 method. The materials represented these categories: ZOE, glass ionomer, silicone, epoxy and tricalcium silicates. One-mm thick samples were made and imaged next to an aluminum step-wedge, using Dexis® software and an Instrumentarium Dental (Finland) x-ray unit at 7mA and 70kV for 0.160s from a distance of 6mm. The digital images were analyzed with Adobe® Photoshop® to determine the equivalent thickness of Al to ±0.5mm. Statistical analyses were performed.
Results: All commercial materials met the ISO13116 minimum of 3mm Al. The epoxy resin sealers were the most radiopaque (9mm Al), and the tricalcium silicate sealers were the least radiopaque (4mm Al). Many sealers have the same radiopaque ingredients, often used in combination, such as bismuth oxide, bismuth oxychloride and barium sulfate. At a 3:1 powder:liquid, tricalcium silicates had 5 to 6mm Al, but only 3 to 4mm Al at 1:1.
Conclusions: The composition of the matrix of the sealer was the most important determinant of the radiopacity. The same radiopaque compound, such as bismuth oxide, had different contributions in the sealer compositions. No simple correlation with the molecular weight of the radiopaque component could be made. However, zirconia-containing root canal materials were less radiopaque than others. Root-end filling materials had lower radiopacity at lower powder to liquid ratios.
Methods: Twenty-one endodontic sealers and three root-end fillers were compared using the ISO13116 method. The materials represented these categories: ZOE, glass ionomer, silicone, epoxy and tricalcium silicates. One-mm thick samples were made and imaged next to an aluminum step-wedge, using Dexis® software and an Instrumentarium Dental (Finland) x-ray unit at 7mA and 70kV for 0.160s from a distance of 6mm. The digital images were analyzed with Adobe® Photoshop® to determine the equivalent thickness of Al to ±0.5mm. Statistical analyses were performed.
Results: All commercial materials met the ISO13116 minimum of 3mm Al. The epoxy resin sealers were the most radiopaque (9mm Al), and the tricalcium silicate sealers were the least radiopaque (4mm Al). Many sealers have the same radiopaque ingredients, often used in combination, such as bismuth oxide, bismuth oxychloride and barium sulfate. At a 3:1 powder:liquid, tricalcium silicates had 5 to 6mm Al, but only 3 to 4mm Al at 1:1.
Conclusions: The composition of the matrix of the sealer was the most important determinant of the radiopacity. The same radiopaque compound, such as bismuth oxide, had different contributions in the sealer compositions. No simple correlation with the molecular weight of the radiopaque component could be made. However, zirconia-containing root canal materials were less radiopaque than others. Root-end filling materials had lower radiopacity at lower powder to liquid ratios.