Saliba E, Abbassi-Ghadi S, Vowles R, Camilleri J, Hooper S, Camilleri J
Department of Oral and Dental Science, Bristol Dental School, University of Bristol, Bristol, UK.
Int Endod J. 2009 Apr;42(4):322-8. doi: 10.1111/j.1365-2591.2008.01512.x. Epub 2009 Feb 7.
To study the effect of addition of various proportions of bismuth oxide on compressive strength and radiopacity of Portland cement.
The compressive strength of white Portland cement and cement replaced with 10, 15, 20, 25 and 30% bismuth oxide was evaluated by testing cylinders 6 mm in diameter and 12 mm high. Twelve cylinders were tested for each material under study. The radiopacity of the cements tested was evaluated using an aluminium step-wedge and densitometer. The optical density was compared with the relevant thickness of aluminium (Al). Statistical analysis was performed using Analysis of Variance (ANOVA) with P = 0.05 and Tukey test to perform multiple comparison tests.
Various additions of bismuth oxide had no significant effect on the strength of the material when compared with the unmodified Portland cement (P > 0.05). The radiopacity of the cements tested ranged from 2.02 mm Al for Portland cement to 9.79 mm Al for the highest bismuth replacement.
Addition of bismuth oxide did not affect the compressive strength of Portland cement. All the bismuth oxide cement mixtures had radio-opacities higher than 3 mm thickness of aluminium.
研究添加不同比例氧化铋对波特兰水泥抗压强度和射线不透性的影响。
通过测试直径6毫米、高12毫米的圆柱体，评估白色波特兰水泥以及用10%、15%、20%、25%和30%氧化铋替代的水泥的抗压强度。对每种研究材料测试12个圆柱体。使用铝阶梯楔形块和密度计评估测试水泥的射线不透性。将光密度与铝（Al）的相关厚度进行比较。使用方差分析（ANOVA），P = 0.05，并进行Tukey检验以进行多重比较测试。
与未改性的波特兰水泥相比，不同添加量的氧化铋对材料强度无显著影响（P > 0.05）。测试水泥的射线不透性范围从波特兰水泥的2.02毫米铝到最高氧化铋替代量时的9.79毫米铝。
添加氧化铋不影响波特兰水泥的抗压强度。所有氧化铋水泥混合物的射线不透性均高于3毫米铝厚度。
