Adhesion of Streptococcus sanguis CH3 to polymers with different surface free energies

Abstract

The adhesion of the oral bacterium Streptococcus sanguis CH3 to various polymeric surfaces with surface free energies (-ys) ranging from 22 to 141 erg cm-2 was investigated. Suspensions containing nine different bacterial concentrations (2.5 x 107 to 2.5 x 109 cells per ml) were used. After adhesion for 1 h at 21°C and a standardized rinsing procedure, the number of attached bacteria per square centimeter (nb) was determined by scanning electron microscopy. The highest number of bacteria was consistently found on polytetrafluorethylene (YS = 22 erg cm2), and the lowest number was found on glass (-ys = 141 erg cm-2) at all bacterial concentrations tested. The overall negative correlation between nb and-ys was weak. However, the slope of the line showing this decrease, calculated from an assumed linear relationship between nb and ys, appeared to depend strongly on the bacterial concentration and increased with increasing numbers of bacteria in the suspension. Analysis of the data for each separate polymer showed that the numbers of attached cells on polyvinyl chloride and polypropylene were higher but that those on polycarbonate were lower than would be expected on basis of a linear relationship between nb and ys. Desorption experiments were performed by first allowing the bacteria to attach to substrata for 1 h, after which the substrata and attached bacteria were removed to bacterial suspensions containing 10-fold lower bacterial concentrations. During the second incubation period, bacteria continued to absorb onto the substrata with high surface free energy (-ys > 45 erg cm 2), whereas on lower-energy surfaces, significant desorption of the cells took place. From the results it was concluded that the surface free energy-ys is an important parameter for the adhesion of bacteria to solids, although it is not the only parameter operating. The surface free energy is presumably more directly related to the binding force rather than to the number of bacteria per surface area.

In vitro adherence of oral streptococci to zirconia core and veneering glass‐ceramics

“…The adhesion of streptococci to solid surfaces has been described as a two‐step process, in which the first step is influenced predominantly by macroscopic substratum properties such as surface free energy 20. Several previous investigations have been focusing on the influence of substratum surface properties on microbial adhesion in vitro 20–27 and in vivo 28–30. Judging from these studies' findings, it can be assumed that substratum surface properties such as surface roughness and surface free energy play pivotal roles in early microbial adhesion.…”

“…Most likely, these results can be attributed to differences in the physico–chemical surface properties of different streptococcal strains. In addition to these aspects, it has been argued that surface free energy is presumably more directly related to the binding force rather than to the number of bacteria per surface area 21. Moreover, Sardin and co‐workers assumed that the ratio of dispersive and polar components has a higher importance for bacterial adhesion to prosthetic materials than the total surface free energy or hydrophobicity 27.…”

The influence of surface free energy and surface roughness on early plaque formation

“…: (i) the lower binding force between bacteria and low-energetic surface; (ii) the selectivity in the bacterial adhesion. The first statement is based on the in vitro study of Van Pelt et al (1985) which illustrated that the solid s.f.e. was directly related to the binding force of bacteria rather than to the nutnber of bacteria per surface area, and oti an in vivo study of who found a weak binding of dental plaque on surfaces with a low s.f.e.…”

Physico-chemistry of initial microbial adhesive interactions – its mechanisms and methods for study

“…The reversibility of oral streptococcal adhesion to substrata with di¡erent wettability after replacing a bacterial suspension by the suspending £uid appeared greater when vG adh s 0 than when vG adh 6 0 with vG adh calculated from Eqs. 7 and 8 [177,178]. Also, when the kinetics of adhesion was followed up to a stationary end-point, it was observed that at the strain level, oral streptococcal adhesion to di¡erent substrata showed strong relationships between adhering numbers and vG adh [149,179].…”