Italian Institute of Technology, via Morego 30, I-16163 Bolzaneto, Genova, Italy.
Biomed Eng Online. 2010 Oct 12;9:59. doi: 10.1186/1475-925X-9-59.
Surface roughness is the main factor determining bacterial adhesion, biofilm growth and plaque formation on the dental surfaces in vivo. Air-polishing of dental surfaces removes biofilm but can also damage the surface by increasing its roughness. The purpose of this study was to investigate the surface damage of different conditions of air-polishing performed in vitro on a recently introduced dental restorative composite.
Abrasive powders of sodium bicarbonate and glycine, combined at different treatment times (5, 10 and 30 s) and distances (2 and 7 mm), have been tested. The resulting root mean square roughness of the surfaces has been measured by means of atomic force microscopy, and the data have been analyzed statistically to assess the significance. Additionally, a fractal analysis of the samples surfaces has been carried out.
The minimum surface roughening was obtained by air-polishing with glycine powder for 5 s, at either of the considered distances, which resulted in a mean roughness of ~300 nm on a 30 × 30 μm2 surface area, whereas in the other cases it was in the range of 400-750 nm. Both untreated surfaces and surfaces treated with the maximum roughening conditions exhibited a fractal character, with comparable dimension in the 2.4-2.7 range, whereas this was not the case for the surfaces treated with the minimum roughening conditions.
For the dental practitioner it is of interest to learn that use of glycine in air polishing generates the least surface roughening on the considered restorative material, and thus is expected to provide the lowest rate of bacterial biofilm growth and dental plaque formation. Furthermore, the least roughening behaviour identified has been correlated with the disappearance of the surface fractal character, which could represent an integrative method for screening the air polishing treatment efficacy.
表面粗糙度是决定细菌在体内附着、生物膜生长和牙面菌斑形成的主要因素。牙面空气抛光可去除生物膜，但也会因增加粗糙度而损坏表面。本研究旨在研究不同条件下对一种新型牙科修复复合材料进行体外空气抛光的表面损伤情况。
分别测试了碳酸氢钠和甘氨酸两种磨料粉，在不同处理时间（5、10 和 30 s）和不同处理距离（2 和 7 mm）下的效果。采用原子力显微镜测量表面的均方根粗糙度，并对数据进行统计学分析以评估其显著性。此外，还对样品表面进行了分形分析。
在考虑的两种距离下，用甘氨酸粉末以 5 s 的时间进行空气抛光，可获得最小的表面粗糙度，平均粗糙度约为 300nm，在 30×30μm2的表面区域内，而在其他情况下，粗糙度范围在 400-750nm 之间。未经处理的表面和用最大粗糙度处理的表面都表现出分形特征，其维度在 2.4-2.7 范围内具有可比性，而用最小粗糙度处理的表面则不具有分形特征。
对于牙科医生来说，了解到在空气抛光中使用甘氨酸可在考虑的修复材料上产生最小的表面粗糙度是很有意义的，因此预计会降低细菌生物膜生长和牙菌斑形成的速度。此外，确定的最小粗糙度行为与表面分形特征的消失相关，这可能是一种筛选空气抛光治疗效果的综合方法。
