Beyth Nurit, Bahir Ran, Matalon Shlomo, Domb Abraham J, Weiss Ervin I
Department of Prosthodontics, Faculty of Dentistry, The Hebrew University, Jerusalem, Israel.
Dent Mater. 2008 Jun;24(6):732-6. doi: 10.1016/j.dental.2007.08.003. Epub 2007 Sep 25.
Polymerized resin composites and nonpolymerized monomers are reported to accelerate bacterial growth. Furthermore, in vivo, resin composite restorations accumulate more plaque than other restorative materials. The purpose of this study was to test the hypothesis that bacteria-composite surface interaction causes changes in surface-topography.
Resin composite disks were polymerized between two glass slides. Streptococcus mutans cells were brought in contact with and grown on the disks for 1 day, 1 week or 1 month. The disks were analyzed using atomic force microscopy. One-month-aged composite specimens were assayed for changes in micro-hardness and bacterial outgrowth.
Atomic force microscopy analysis revealed a time-dependent increase in root mean square (RMS) roughness (p<0.0001). S. mutans outgrowth was accelerated following direct contact with the surface of aged composites, with no changes in micro-hardness.
Our results show that S. mutans growth on resin composite increases surface roughness without affecting micro-hardness. The change in surface integrity may further accelerate biofilm accumulation.
据报道，聚合树脂复合材料和未聚合单体可加速细菌生长。此外，在体内，树脂复合材料修复体比其他修复材料积累更多菌斑。本研究的目的是检验细菌与复合材料表面相互作用会导致表面形貌变化这一假设。
树脂复合材料圆盘在两片载玻片之间聚合。变形链球菌细胞与圆盘接触并在其上生长1天、1周或1个月。使用原子力显微镜对圆盘进行分析。对1个月龄的复合材料标本进行显微硬度和细菌生长变化检测。
原子力显微镜分析显示，均方根（RMS）粗糙度随时间增加（p<0.0001）。与老化复合材料表面直接接触后，变形链球菌生长加速，显微硬度无变化。
我们的结果表明，变形链球菌在树脂复合材料上生长会增加表面粗糙度，而不影响显微硬度。表面完整性的变化可能会进一步加速生物膜的积累。
