Department of Prosthetic Dentistry, Regensburg University Medical Centre, 93042 Regensburg, Germany.
Arch Oral Biol. 2009 Jun;54(6):595-601. doi: 10.1016/j.archoralbio.2009.03.004. Epub 2009 Apr 16.
Resin composite materials tend to accumulate microorganisms and dental plaque, which in turn may induce secondary caries around adhesive restorations. The aim of the present in vitro study was to evaluate the antibacterial activity of a resin composite material loaded with silver microparticles against Streptococcus mutans.
Circular specimens (10.0mm in diameter) of a resin composite matrix loaded with two different concentrations of a silver additive (Comp0.3: 0.3%; Comp0.6: 0.6%) and one unloaded reference composite matrix (Comp0: 0%) were made. Surface roughness R(a) was assessed by perthometer measurements and hydrophobicity according to water contact angles was determined by computerized image analysis. The specimens were incubated in a S. mutans suspension (1h, 37 degrees C) and adhering streptococci were quantified by using a biofluorescence assay (Alamar blue/Resazurin). Additionally, the viability of adhering bacteria was assessed by live/dead cell labelling in combination with fluorescence microscopy.
Statistically significant differences between the median water contact angles of Comp0 (66.3 degrees ), Comp0.3 (76.7 degrees ), and Comp0.6 (89.4 degrees ) were observed (p<0.001). A three- to fourfold higher amount of adhering S. mutans was found on reference Comp0 (12,093relative fluorescence units) than on Comp0.3 (4258rfu) and Comp0.6 (3292) (p<0.001 for both). Significantly higher percentages of dead cells than on Comp0 (0.5%) were found on Comp0.3 (6.1%) and on Comp0.6 (10.1%) (p<0.001 for both).
The addition of microparticulate silver to a resin composite material increased the surface hydrophobicity and reduced the number of adhering streptococci. Simultaneously it increased the percentage of dead and inactive cells on the composite surface. Thus, silver additives seem to demonstrate anti-adherence activity as well as a bactericidal effect.
树脂复合材料容易聚集微生物和牙菌斑，这反过来可能会在黏附修复体周围引发继发龋。本体外研究的目的是评估载银纳米颗粒的树脂复合材料对变形链球菌的抗菌活性。
制作了一种载银添加剂浓度分别为 0.3%（Comp0.3）和 0.6%（Comp0.6）的树脂复合材料基质的圆形试件（直径 10.0mm）和一个未加载参考复合材料基质（Comp0：0%）。用轮廓仪测量表面粗糙度 Ra，用计算机图像分析根据水接触角确定疏水性。将标本在变形链球菌悬浮液中孵育（1h，37°C），并用生物荧光测定法（Alamar blue/Resazurin）定量附着链球菌。此外，通过活/死细胞标记结合荧光显微镜评估附着细菌的活力。
Comp0（66.3°）、Comp0.3（76.7°）和 Comp0.6（89.4°）的中位水接触角之间存在统计学显著差异（p<0.001）。在参考 Comp0 上发现附着的变形链球菌数量比 Comp0.3（4258rfu）和 Comp0.6（3292）高 3 到 4 倍（两者均 p<0.001）。在 Comp0.3（6.1%）和 Comp0.6（10.1%）上发现的死亡细胞百分比明显高于 Comp0（0.5%）（两者均 p<0.001）。
将微米银颗粒添加到树脂复合材料中增加了表面疏水性并减少了附着链球菌的数量。同时，它增加了复合材料表面上死亡和失活细胞的百分比。因此，银添加剂似乎具有抗黏附活性和杀菌作用。
