D'Alpino Paulo Henrique Perlatti, Svizero Nádia da Rocha, Bim Júnior Odair, Valduga Claudete Justina, Graeff Carlos Frederico de Oliveira, Sauro Salvatore
Biomaterials Research Group, School of Dentistry, Universidade Anhanguera de São Paulo (UNIAN - SP), Rua Maria Cândida, 1813, São Paulo, SP, Brazil, CEP 02071-013.
Hospital de Reabilitação de Anomalias Craniofaciais (HRAC-USP), Universidade de São Paulo, Bauru, SP, Brazil.
Clin Oral Investig. 2016 Jun;20(5):1011-9. doi: 10.1007/s00784-015-1599-9. Epub 2015 Sep 21.
The aim of this study is to evaluate the distribution of the filler size along with the zeta potential, and the integrity of silane-bonded filler surface in different types of restorative dental composites as a function of the material age condition.
Filtek P60 (hybrid composite), Filtek Z250 (small-particle filled composite), Filtek Z350XT (nanofilled composite), and Filtek Silorane (silorane composite) (3M ESPE) were tested at different stage condition (i.e., fresh/new, aged, and expired). Composites were submitted to an accelerated aging protocol (Arrhenius model). Specimens were obtained by first diluting each composite specimen in ethanol and then dispersed in potassium chloride solution (0.001 mol%). Composite fillers were characterized for their zeta potential, mean particle size, size distribution, via poly-dispersion dynamic light scattering. The integrity of the silane-bonded surface of the fillers was characterized by FTIR.
The material age influenced significantly the outcomes; Zeta potential, filler characteristics, and silane integrity varied both after aging and expiration. Silorane presented the broadest filler distribution and lowest zeta potential. Nanofilled and silorane composites exhibited decreased peak intensities in the FTIR analysis, indicating a deficiency of the silane integrity after aging or expiry time.
Regardless to the material condition, the hybrid and the small-particle-filled composites were more stable overtime as no significant alteration in filler size distribution, diameter, and zeta potential occurred. A deficiency in the silane integrity in the nanofilled and silorane composites seems to be affected by the material stage condition.
The materials conditions tested in this study influenced the filler size distribution, the zeta potential, and integrity of the silane adsorbed on fillers in the nanofilled and silorane composites. Thus, this may result in a decrease of the clinical performance of aforementioned composites, in particular, if these are used after inappropriate storage conditions.
本研究旨在评估不同类型的牙科修复复合材料中填料尺寸的分布、zeta电位以及硅烷键合填料表面的完整性与材料老化状态之间的关系。
对Filtek P60（混合复合材料）、Filtek Z250（小颗粒填料复合材料）、Filtek Z350XT（纳米填料复合材料）和Filtek Silorane（硅氧烷复合材料）（3M ESPE）在不同阶段条件下（即新鲜/新的、老化的和过期的）进行测试。复合材料采用加速老化方案（阿累尼乌斯模型）。首先将每个复合材料样本在乙醇中稀释，然后分散在氯化钾溶液（0.001 mol%）中，从而获得样本。通过多分散动态光散射对复合填料的zeta电位、平均粒径、粒径分布进行表征。通过傅里叶变换红外光谱（FTIR）对填料硅烷键合表面的完整性进行表征。
材料老化对结果有显著影响；老化和过期后，zeta电位、填料特性和硅烷完整性均发生变化。硅氧烷复合材料呈现出最宽的填料分布和最低的zeta电位。纳米填料和硅氧烷复合材料在FTIR分析中显示出峰强度降低，表明老化或过期后硅烷完整性不足。
无论材料状态如何，混合复合材料和小颗粒填料复合材料随着时间的推移更稳定，因为填料尺寸分布、直径和zeta电位没有显著变化。纳米填料和硅氧烷复合材料中硅烷完整性的不足似乎受材料阶段条件的影响。
本研究中测试的材料条件影响了纳米填料和硅氧烷复合材料中填料的尺寸分布、zeta电位以及吸附在填料上的硅烷的完整性。因此，这可能会导致上述复合材料的临床性能下降，特别是如果在不适当的储存条件下使用这些材料。
