Radiopacity evaluation of calcium aluminate α-aluminate and wollastonite calcium α-aluminate with the use of two types of radiopacifiers in comparison to Pro-root MTA and Portland cement

Introduction: Calcium aluminate α-aluminate (CAA) and wollastonite calcium α-aluminate (WOLCA) are new cements with sufficient biocompatibility and sealing ability. Radiopacity of these cements have not been evaluated. The aim of the present study was to determine the minimum amounts of two types of radiopacifiers necessary to incorporate into these two cements in order to achieve the necessary radiopacity in comparison with Pro-root MTA and Portland cement. Materials and Methods: In this experimental study, bismuth oxide and barium sulfate, with concentrations of 10% and 20%, were added to CAA and WOLCA as radiopacifiers and the radiopacity results were compared with that of Pro-root MTA as gold standard. Sixty Teflon ring specimens, measuring 10 mm in diameter and 1 mm in thickness, were prepared according to ISO standard of 6876, 2001. The specimens were divided into 12 groups of 5 and placed onto PSP cassette plates. The specimens were radiographed under exposure conditions of 63 kVp, 8 mA and 0.6 seconds. Data were analyzed by one-way ANOVA at a significance level of 0.95. Results: The materials exhibited radiopacity (in mm of aluminum) in the following descending order: Pro-root MTA, 0.8 gr of CAA + 0.2 gr of bismuth oxide, 0.8 gr of WOLCA + 0.2 gr of bismuth oxide, 0.9 gr of WOLCA + 0.1 gr of bismuth oxide (p value < 0.001). Conclusion: For appropriate radiopacity based on international standards, combination of 0.8 gr of CAA + 0.2 gr of bismuth oxide, 0.8 gr of WOLCA + 0.2 gr of bismuth oxide and 0.9 gr of WOLCA + 0.1 gr of bismuth oxide are recommended. Key words: Mineral trioxide aggregate, Radiography, Retrograde obturation