血液环境下Biodentine与MTA的颜色稳定性研究

目的 比较牙体牙髓治疗中常用的骨水泥材料Biodentine与三氧化矿物凝聚体(mineral trioxide ag-gregrate,MTA)在与血液接触条件下的颜色稳定性,并探讨其可能的变色原因.方法 制备直径5 mm、高3 mm的Biodentine和MTA圆盘,将每种材料的24个圆盘随机分配到去离子水组和脱纤...

Research on the color stability of Biodentine and MTA within the blood environment

Objective To compare the color stability of Biodentine and mineral trioxide aggregate(MTA)within the blood environment in vitro and to further investigate the underlying reasons for such color instability.Methods We first generated Biodentine and MTA discs with a diameter of 5 mm and a height of 3 mm.24 discs of each material were randomly divided into two groups:the deionized water group and the defibrinated sheep blood group.Discs of each group were immersed for 1 day or 7 days before assessments.First,all discs were photographed to directly compare the discoloration of Biodentine and MTA.The color degree of the two materials was tested by a spectrophotometer.Then,the highresolution morphological characteristics were observed by scanning electron microscopy.Finally,the chemical contents of each element in the material were measured by energydispersive spectroscopy.Results Compared to immediately after stripping,a change in the brightness of discs after immersion in defibrinated sheep blood for 1 day was observed only in MTA.On the 7th day after being immersed in blood,the colors of both the Biodentine and MTA discs darkened and turned deep red,but the darkness of the MTA discs increased significantly.The color change of MTA immersed in blood was measured on a spectrophotometer with a greater 7dayΔE(21.257±0.955)than the Biodentine 7dayΔE(5.833±0.501)(t=24.781,P<0.001).MTA exhibits more discoloration as the immersion time goes on.A significant difference was noted between the 1dayΔE(6.233±0.888)and the 7dayΔE(t=19.956,P<0.001)of MTA immersed in blood.However,there was no statistically significant difference between the 1dayΔE(6.790±0.831)and the 7dayΔE(t=1.707,P=0.163)of Biodentine immersed in blood.It was observed by scanning electron microscopy that after 7 days of immersion in the defibrinated sheep blood,the surface porosity of MTA was larger than that of Biodentine,and the crystal edge of MTA became rounded and blunt.The analysis by energydispersive Xray spectroscopy showed that the oxygen content decreased and the bismuth content increased in MTA after immersion in defibrinated sheep blood for 7 days.Zirconium was not detected in Biodentine due to its low radiodensity,but the contents of other elements were stable in Biodentine after immersion in defibrinated sheep blood for 7 days.Conclusion The color stability of Biodentine within the blood environment is better than that of MTA in vitro,which is mainly related to the low surface porosity and stable composition of the antiradiation agent of Biodentine.