The Use of Positively Charged or Low Surface Free Energy Coatings versus Polymer Brushes in Controlling Biofilm Formation

2006 ◽  
pp. 138-144 ◽  
Author(s):  
Astrid Roosjen ◽  
Willem Norde ◽  
Henny C. Mei ◽  
Henk J. Busscher
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Biofilm Formation ◽  
Polymer Brushes ◽  
Positively Charged

Influence of Nanocomposite Surface Coating on Biofilm Formation In Situ

2007 ◽  
Vol 7 (12) ◽  
pp. 4642-4648 ◽  
Author(s):  
M. Hannig ◽  
L. Kriener ◽  
W. Hoth-Hannig ◽  
C. Becker-Willinger ◽  
H. Schmidt
Keyword(s):  
Free Energy ◽  
Composite Coating ◽  
Surface Free Energy ◽  
Biofilm Formation ◽  
Tooth Surface ◽  
Dense Layer ◽  
Electron Microscopic ◽  
Nano Composite ◽  
Nano Composite Coating

Caries and periodontitis, the most wide-spread oral diseases around the world, are caused by bacterial adherence and biofilm formation onto the natural as well as restored tooth surface. One possible way to prevent the pathogenic consequences of intraoral biofilm formation might be the modification of the tooth surface by application of an anti-adhesive coating that interferes with the bacterial attachment and subsequent bacterial accumulation. The objective of this study was to investigate the effect of an experimental, low surface free energy nano-composite coating material on biofilm formation in situ. For this purpose, an organic/inorganic nano-composite coating (NANOMER®, INM, Saarbrücken, Germany) with a surface free energy of 18–20 mJ/m2 was applied to enamel as well as titanium specimens. The nano-composite coated specimens and un-coated controls were attached to removable intraoral splints and carried by volunteers over 24 h in the oral cavity. After intraoral exposure, specimens were processed for transmission electron microscopic analysis. On non-coated enamel and titanium control samples a multi-layer of adherent bacteria was found. In contrast, on nano-composite coated specimens strongly reduced biofilm formation was observed. In most areas of the surface-coated specimens only a 10–20 nm thick electron dense layer of adsorbed salivary proteins with adherent protein agglomerates of 20–80 nm diameter could be detected. In addition, detachment of the adsorbed biofilm from the nano-composite coated surfaces was evident in electron microscopic micrographs. The present investigation provides ultrastructural evidence that it is possible to cover enamel as well as titanium with a nano-composite coating revealing easy-to-clean surface properties that cause reduced biofilm formation and accelerated removal of adherent biofilms under oral conditions.

scholarly journals Biofilm formation on pyrolytic carbon heart valves: Influence of surface free energy, roughness, and bacterial species

2007 ◽  
Vol 134 (4) ◽  
pp. 1025-1032 ◽  
Author(s):  
Pierre-Yves Litzler ◽  
Laetitia Benard ◽  
Noëlle Barbier-Frebourg ◽  
Sebastien Vilain ◽  
Thierry Jouenne ◽  
...  
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Biofilm Formation ◽  
Heart Valves ◽  
Bacterial Species ◽  
Pyrolytic Carbon

Smectic A-Smectic B interface : faceting and surface free energy measurement

1989 ◽  
Vol 50 (24) ◽  
pp. 3527-3534 ◽  
Author(s):  
P. Oswald ◽  
F. Melo ◽  
C. Germain
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Energy Measurement ◽  
Smectic A

Examination of the lubricant storing and releasing ability of thermally sprayed surfaces

2011 ◽  
Vol 2 (2) ◽  
pp. 101-105
Author(s):  
L. Fazekas ◽  
Z. S. Tiba ◽  
G. Kalácska
Keyword(s):  
Free Energy ◽  
Surface Energy ◽  
Surface Free Energy ◽  
Essential Role ◽  
Index Number ◽  
Adhesion Ability ◽  
Thermally Sprayed ◽  
Proper Operation

Abstract The lubricant storing and releasing ability of the thermally sprayed surfaces plays an essential role in the proper operation of the components. In the case of porous sprayed surfaces the lubricant storing and releasing ability depends mainly on porosity and the surface energy (adhesion susceptibility). The adhesion ability can also be expressed indirectly with an index number that is by determining the surface free energy.

Molecular orientation of liquid aliphatic hydrocarbons on the surface and at the interface with water

1989 ◽  
Vol 54 (12) ◽  
pp. 3171-3186 ◽  
Author(s):  
Jan Kloubek
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Molecular Orientation ◽  
Phase Changes ◽  
Aliphatic Hydrocarbons ◽  
Water Molecules ◽  
Free Energies ◽  
Dispersion Component ◽  
System Water ◽  
Orientation Of Molecules

The validity of the Fowkes theory for the interaction of dispersion forces at interfaces was inspected for the system water-aliphatic hydrocarbons with 5 to 16 C atoms. The obtained results lead to the conclusion that the hydrocarbon molecules cannot lie in a parallel position or be randomly arranged on the surface but that orientation of molecules increases there the ration of CH3 to CH2 groups with respect to that in the bulk. This ratio is changed at the interface with water so that the surface free energy of the hydrocarbon, γH, rises to a higher value, γ’H, which is effective in the interaction with water molecules. Not only the orientation of molecules depends on the adjoining phase and on the temperature but also the density of hydrocarbons on the surface of the liquid phase changes. It is lower than in the bulk and at the interface with water. Moreover, the volume occupied by the CH3 group increases on the surface more than that of the CH2 group. The dispersion component of the surface free energy of water, γdW = 19.09 mJ/m2, the non-dispersion component, γnW = 53.66 mJ/m2, and the surface free energies of the CH2 and CH3 groups, γ(CH2) = 32.94 mJ/m2 and γ(CH3) = 15.87 mJ/m2, were determined at 20 °C. The dependence of these values on the temperature in the range 15-40 °C was also evaluated.

scholarly journals Effect of calcination temperature on neptunium dioxide microstructure and dissolution

2020 ◽  
Vol 7 (12) ◽  
pp. 3869-3876
Author(s):  
Kathryn M. Peruski ◽  
Brian A. Powell
Keyword(s):  
Grain Size ◽  
Free Energy ◽  
Surface Area ◽  
Calcination Temperature ◽  
Surface Free Energy ◽  
Neptunium Dioxide

Solubility of neptunium dioxide decreases as microstructure grain size increases, likely due to decreasing surface free energy and surface area.

Bifunctional Composites for Biofilms Modulation on Cervical Restorations

2021 ◽  
pp. 002203452110181
Author(s):  
A.A. Balhaddad ◽  
I.M. Garcia ◽  
L. Mokeem ◽  
M.S. Ibrahim ◽  
F.M. Collares ◽  
...  
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Contact Angles ◽  
Bacterial Biofilm ◽  
Dental Composite ◽  
Log P ◽  
Rrna Gene ◽  
Cervical Lesions ◽  
Biofilm Growth ◽  
Biofilm Development

Cervical composites treating root carious and noncarious cervical lesions usually extend subgingivally. The subgingival margins of composites present poor plaque control, enhanced biofilm accumulation, and cause gingival irritation. A potential material to restore such lesions should combine agents that interfere with bacterial biofilm development and respond to acidic conditions. Here, we explore the use of new bioresponsive bifunctional dental composites against mature microcosm biofilms derived from subgingival plaque samples. The designed formulations contain 2 bioactive agents: dimethylaminohexadecyl methacrylate (DMAHDM) at 3 to 5 wt.% and 20 wt.% nanosized amorphous calcium phosphate (NACP) in a base resin. Composites with no DMAHDM and NACP were used as controls. The newly formulated 5% DMAHDM–20% NACP composite was analyzed by micro-Raman spectroscopy and transmission electron microscopy. The wettability and surface-free energy were also assessed. The inhibitory effect on the in vitro biofilm growth and the 16S rRNA gene sequencing of survival bacterial colonies derived from the composites were analyzed. Whole-biofilm metabolic activity, polysaccharide production, and live/dead images of the biofilm grown over the composites complement the microbiological assays. Overall, the designed formulations had higher contact angles with water and lower surface-free energy compared to the commercial control. The DMAHDM-NACP composites significantly inhibited the growth of total microorganisms, Porphyromonas gingivalis, Prevotella intermedia/nigrescens, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum by 3 to 5-log ( P < 0.001). For the colony isolates from control composites, the composition was typically dominated by the genera Veillonella, Fusobacterium, Streptococcus, Eikenella, and Leptotrichia, while Fusobacterium and Veillonella dominated the 5% DMAHDM–20% NACP composites. The DMAHDM-NACP composites contributed to over 80% of reduction in metabolic and polysaccharide activity. The suppression effect on plaque biofilms suggested that DMAHDM-NACP composites might be used as a bioactive material for cervical restorations. These results may propose an exciting path to prevent biofilm growth and improve dental composite restorations’ life span.

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