Atomic force microscopy in vitro study of surface roughness and fractal character of a dental restoration composite after air-polishing

Abstract

BackgroundSurface 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.MethodsAbrasive 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.ResultsThe 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.ConclusionsFor 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.

Effect of air-polishing on properties of nanocomposite submitted to coffee, red wine and cigarette smoke

“…In agreement with other studies 3,[20][21][22][23] , the SBAP was able to increase the surface roughness even in a nanoparticulate composite.The abrasive jet action, which contains sodium bicarbonate particles, on the restorative material surface was demonstrated by comparison of the groups with and without SBAP at time 2 (after the SBAP jet application). The superficial abrasion of a composite resin leads to the loss of surface inorganic particles, increasing the roughness and it interferes in the reflective ability of the material 20 .…”

Surface roughness and morphology of dental nanocomposites polished by four different procedures evaluated by a multifractal approach

“…In the subfield of dental materials, fractal and multifractal analyses have been applied for the quantitative description of the surfaces morphology [30][31][32][33][34][35].…”

Surface roughness and hardness evaluation of some base metal alloys and denture base acrylics used for oral rehabilitation

“…Atomic forces attract the fine-tipped stylus to the surface and the reaction force generated while the cantilever bending is used to indicate the surface profile [3,13,14]. AFM provides a real topographical three-dimensional image and quantitative values that allow comparisons among materials [3,15].…”