Department of Dental Materials and Prosthodontics, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto, SP, Brazil.
J Endod. 2011 Jan;37(1):67-71. doi: 10.1016/j.joen.2010.10.001.
The aim of this study was to evaluate the radiopacity of calcium aluminate cement (EndoBinder) with 3 different radiopacifiers (bismuth oxide, zinc oxide, or zirconium oxide) in comparison with gray mineral trioxide aggregate (GMTA), white MTA, and dental structures (enamel and dentin).
Eighteen test specimens of each cement with thicknesses of 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mm (n = 3) were made by using a stainless steel matrix and were adapted to a standardizing device (8 × 7 cm) with a graduated aluminum stepwedge varying from 2.0-16.0 mm in thickness. To compare the radiopacity of the cements with that of dental structures, slices of first molars with a thickness increasing from 0.5-3.0 mm were obtained and placed on the standardizing device. One occlusal radiograph for each tested cement was taken, with exposure time of 0.1 seconds and focus-film distance of 20 cm. Films were processed in an automatic device, and the mean radiopacity values were obtained by using a photodensitometer.
Mean values showed that the thicker the specimen was, the greater was its radiopacity. Only EndoBinder + bismuth oxide (EBBO) and GMTA demonstrated radiopacity values greater than 3.0 mm of the aluminum scale for all thicknesses. When zinc oxide was used as radiopacifier agent, EndoBinder only reached the desired radiopacity with a thickness of 2.0 mm, and with zirconium oxide it was 2.5 mm.
Bismuth oxide was the most efficient radiopacifier for EndoBinder, providing adequate radiopacity in all studied thicknesses, as recommended by ISO 6876, being similar to GMTA.
本研究旨在评估 3 种不同的显影剂（氧化铋、氧化锌或氧化锆）的钙铝酸盐水泥（EndoBinder）的射线可透性，与灰色矿物三氧化物聚合体（GMTA）、白色 MTA 和牙体结构（牙釉质和牙本质）进行比较。
用不锈钢基质制作了厚度为 0.5、1.0、1.5、2.0、2.5 和 3.0 mm 的每种水泥的 18 个测试标本（n = 3），并适应于标准设备（8×7 cm），其中有一个厚度从 2.0-16.0 mm 变化的分级铝梯阶。为了比较水泥的射线可透性与牙体结构的射线可透性，从第一磨牙获得厚度从 0.5-3.0 mm 增加的切片，并将其放置在标准设备上。对每个测试水泥进行 1 次咬合射线照相，曝光时间为 0.1 秒，焦点-胶片距离为 20 cm。胶片在自动设备中处理，使用光密度计获得平均射线可透性值。
平均值表明，标本越厚，其射线可透性越大。只有 EndoBinder + 氧化铋（EBBO）和 GMTA 在所有厚度下均显示出大于铝标度 3.0 mm 的射线可透性值。当使用氧化锌作为显影剂时，EndoBinder 仅在 2.0 mm 的厚度下达到所需的射线可透性，而使用氧化锆时则为 2.5 mm。
氧化铋是 EndoBinder 最有效的显影剂，在 ISO 6876 推荐的所有研究厚度下均提供足够的射线可透性，与 GMTA 相似。
