Effect of biofilm exposure on marginal integrity of composite restorations.
Effect of biofilm exposure on marginal integrity of composite restorations.
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发表时间：
2020-08
影响因子：
1.4
通讯作者：
A. Mushashe;Sarah A de Almeida;J. Ferracane;J. Merritt;G. M. Correr
中科院分区：
文献类型：
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作者：
A. Mushashe;Sarah A de Almeida;J. Ferracane;J. Merritt;G. M. Correr
目的评价细菌暴露对生物活性玻璃（BAG）复合材料牙本质-树脂界面边缘完整性的影响。方法用计算机控制的铣削系统将宽5 mm、深1.5mm的窝洞制备成牙本质盘。在施加粘合剂之后，通过增量技术用具有不同填料组成的实验树脂复合材料（50：50 BisGMA/TEGDMA：72wt%填料）修复腔体制备物（n=3-5）：对照-67wt%硅烷化锶玻璃和5wt%气溶胶-二氧化硅填料和BAG -57wt%硅烷化锶玻璃和15wt%BAG-65wt%二氧化硅。然后将样品储存在无菌Todd-Hewitt培养基中或与变形链球菌（UA 159）在37°C、5%CO2下共孵育1-2周。对于与活生物膜共孵育的样品，进行荧光素酶测定以评估其活力。在每个储存条件之前和之后对表面进行压印，并在扫描电子显微镜中检查复制品。使用图像分析软件（Image J），定量评估不连续边缘百分比（%DM）。使用双因素ANOVA分析数据，然后进行Tukey检验（α= 0.05）。结果间隙尺寸范围为7-23 µm。细菌暴露显著增加了两组中的%DM，主要是由于形成了新的间隙区域。在%DM和生物膜活力方面，对照和BAG复合材料之间没有差异。细菌暴露促进复合材料修复体边缘完整性的降解，在有和没有BAG的复合材料之间没有差异。临床意义与活生物膜一起孵育的样本在边缘中具有较高的间隙百分比，证实了致龋细菌对边缘降解的负面影响。为这种协同作用定义的参数可以帮助理解边缘不连续性的多因素方面，因此，预测复合材料在具有挑战性的口腔环境中的行为。
PURPOSE To evaluate the effect of bacterial exposure on the marginal integrity of dentin-resin interfaces for composites with and without bioactive glass (BAG). METHODS Cavity preparations of 5 mm width and 1.5 mm depth were machined into dentin disks by means of a computer controlled milling system. After applying the bonding agent, cavity preparations (n=3-5) were restored by incremental technique with experimental resin composites (50:50 BisGMA/TEGDMA: 72wt% filler) with different filler compositions: control - 67 wt% silanated strontium glass and 5wt% aerosol-silica filler and BAG - 57 wt% silanated strontium glass and 15 wt% BAG-65 wt% silica. Samples were then stored in sterile Todd-Hewitt media or co-incubated with Streptococcus mutans (UA 159), at 37°C, 5% CO2 for 1-2 weeks. For samples co-incubated with a living biofilm, a luciferase assay was performed in order to assess its viability. Surfaces were impressed before and after each storage condition and replicas examined in a scanning electron microscope. Using image analysis software (Image J), the discontinuous margins percentage (%DM) was quantitatively assessed. Data were analyzed using two-way ANOVA followed by Tukey's test (α= 0.05). RESULTS Gap size ranged between 7-23 µm. The bacterial exposure significantly increased the %DM in both groups predominantly due to the formation of new gap regions. There was no difference between control and BAG composites regarding %DM and the biofilm viability. Bacterial exposure promoted degradation of composite restoration marginal integrity, with no difference between composites with and without BAG. CLINICAL SIGNIFICANCE The samples incubated with living biofilm had a higher gap percentage in the margins, confirming the negative effect of cariogenic bacteria on margin degradation. The parameters defined for such synergy can help to understand the multi-factorial aspect of marginal discontinuity and therefore, predict the behavior of composite restorations subjected to the challenging oral environment.