Garcia Isadora Martini, Leitune Vicente Castelo Branco, Takimi Antonio Shigueaki, Bergmann Carlos Pérez, Samuel Susana Maria Werner, Melo Mary Anne, Collares Fabrício Mezzomo
Dental Materials Laboratory, School of Dentistry, Federal University of Rio Grande do Sul, Rua Ramiro Barcelos 2492, Rio Branco, Porto Alegre, RS 90035-003, Brazil.
Laboratory for Electrochemical Processes and Corrosion, Engineering School, Federal University of Rio Grande do Sul, Bento Gonçalves, 9500, Prédio 43427, Sala 216, Porto Alegre, RS 91501-970, Brazil.
J Funct Biomater. 2020 Feb 11;11(1):7. doi: 10.3390/jfb11010007.
The insufficient radiopacity of dental adhesives applied under composite restorations makes the radiographic diagnosis of recurrent caries challenging. Consequently, the misdiagnosis may lead to unnecessary replacement of restorations. The aims of this study were to formulate experimental dental adhesives containing cerium dioxide (CeO) and investigate the effects of different loadings of CeO on their radiopacity and degree of conversion for the first time. CeO was characterized by X-ray diffraction analysis, Fourier transforms infrared spectroscopy, and laser diffraction for particle size analysis. Experimental dental adhesives were formulated with CeO as the inorganic filler with loadings ranging from 0.36 to 5.76 vol.%. The unfilled adhesive was used as a control. The studied adhesives were evaluated for dispersion of CeO in the polymerized samples degree of conversion, and radiopacity. CeO presented a monoclinic crystalline phase, peaks related to Ce-O bonding, and an average particle size of around 16 µm. CeO was dispersed in the adhesive, and the addition of these particles increased the adhesives' radiopacity ( < 0.05). There was a significant decrease in the degree of conversion with CeO loadings higher than 1.44 vol.%. However, all materials showed a similar degree of conversion in comparison to commercially available adhesives. CeO particles were investigated for the first time as a promising compound to improve the radiopacity of the dental adhesives.
复合修复体下方使用的牙科粘合剂射线不透性不足，使得复发性龋齿的影像学诊断具有挑战性。因此，误诊可能导致修复体的不必要更换。本研究的目的是首次配制含二氧化铈（CeO）的实验性牙科粘合剂，并研究不同含量的CeO对其射线不透性和转化率的影响。通过X射线衍射分析、傅里叶变换红外光谱和激光衍射对CeO进行粒度分析表征。以CeO作为无机填料，含量范围为0.36至5.76体积%，配制实验性牙科粘合剂。未填充的粘合剂用作对照。对所研究的粘合剂进行CeO在聚合样品中的分散性、转化率和射线不透性评估。CeO呈现单斜晶相、与Ce-O键相关的峰，平均粒径约为16 µm。CeO分散在粘合剂中，添加这些颗粒增加了粘合剂的射线不透性（P<0.05）。当CeO含量高于1.44体积%时，转化率显著降低。然而，与市售粘合剂相比，所有材料的转化率相似。首次研究了CeO颗粒作为改善牙科粘合剂射线不透性的一种有前景的化合物。
