Surface Free Energy Changes of Human Enamel during Pellicle Formation

Jong, H. P. de; Boer, Pascal de; Busscher, Henk J.; Pelt, A. W. J. van; Arends, Johannes

doi:10.1159/000260795

Cited by 38 publications

(20 citation statements)

References 16 publications

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“…The results indicated that enamel shows greater variation in the contact angle values than dentin, which correspond well with previously reported data [16][17][18][19][20]. The observed variation in enamel and not in dentin must be related both to the inorganic/organic material ratio in these tissues (enamel: approx.…”

Section: Discussionsupporting

confidence: 91%

Wettability modification of human tooth surface by water and UV and electron-beam radiation

Tiznado-Orozco

Reyes‐Gasga

Elefterie

et al. 2015

Materials Science and Engineering: C

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Section: Discussionsupporting

confidence: 91%

Wettability modification of human tooth surface by water and UV and electron-beam radiation

Tiznado-Orozco

Reyes‐Gasga

Elefterie

et al. 2015

Materials Science and Engineering: C

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“…Salivary protein adsorption under the in vitro conditions prevailing in this study also gives rise to an increased surface free energy, although not up to the extent previously ob served by de Jong et al [1984a], This could well be due to differences in the rinsing procedures.…”

Section: Discussionmentioning

confidence: 45%

“…No information about the chemical composition of the surface is obtained, however. We have employed the technique to monitor adsorption of salivary pro teins [de Jong et al, 1984a] and fluorides [de Jong et al, 1984b;Perdok et al, 1988a] on the enamel surface.X-ray photoelectron spectroscopy (XPS), though less surface sensitive (information depth approxi mately 20-40 À), can be employed to determine the elemental composition of a surface [Andrade, 1985]. The technique is based on ejection of electrons from surface atoms by X-ray irradiation which are then dis criminated with respect to their binding energy in a specific element.…”

mentioning

confidence: 99%

Elemental Surface Concentration Ratios and Surface Free Energies of Human Enamel after Application of Chlorhexidine and Adsorption of Salivary Constituents

Perdok¹,

Vandermei²,

Genet

et al. 1989

Caries Res

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In vitro adsorption of chlorhexidine from a commercially available chlorhexidine-containing (0.12%) mouthrinse (Peridex) on both ground and polished and on saliva-coated enamel was studied by X-ray photoelectron spectroscopy and contact angle measurements. Furthermore, adsorption of salivary constituents was studied on chlorhexidine-treated enamel. Changes in the elemental surface composition obtained by X-ray photoelectron spectroscopy clearly demonstrated adsorption of chlorhexidine from the mouthrinse as indicated by increased N and C signals which were in all cases accompanied by a higher enamel surface free energy, estimated from the contact angle data. In addition, it was found that salivary constituents adsorb less to chlorhexidine-treated enamel than to ground and polished enamel and, moreover, that adsorbed salivary constituents were desorbed by chlorhexidine. In vivo, the effect of a 3-week use of chlorhexidine was compared with the use of a placebo and habitual oral hygiene of 10 volunteers by means of clinical contact angle measurements. Also in vivo adsorption of chlorhexidine yielded elevated surface free energies with respect to habitual oral hygiene or a placebo. Thus in vivo, the well-known favourable effects of the bactericidal properties of chlorhexidine completely overrule the unfavourable effects of high enamel surface free energies.

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“…Previous studies implicate hydrophobic interactions in the adhesion of S. sanguis (20). Both the cell and the pellicle have hydrophobic surfaces (9,27), and S. sanguis mutants exhibiting a hydrophilic phenotype are also adhesion deficient (11). Thus, hydrophobicity probably stabilizes the initial association mediated through electrostatic interactions and temper-s the marked heat capacity found in purely electrostatic adsorption systems.…”

Section: Resultsmentioning

confidence: 99%

Energetics of the initial phase of adhesion of Streptococcus sanguis to hydroxylapatite

Taylor¹,

Doyle²

1987

J Bacteriol

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The initial adhesion of Streptococcus sanguis 10556 to artificial salivary pellicle and to bare hydroxylapatite was studied at several temperatures between 18 and 37C. When the natural logarithms of rate constants for adsorption and desorption were plotted against reciprocal temperatures in Arrhenius plots, curved lines were obtained, indicating that the thermodynamic quantities of enthalpy and entropy of activation were temperature dependent. For the bare hydroxylapatite system, the heat capacity (ACp = dH/dT) was large and negative. ACp was also negative for adhesion to saliva-coated hydroxylapatite, although its value was lower. Negative heat capacities, when coupled with favorable entropy, are often indicative of either electrostatic or hydrophobic interactions. When electrolyte (100 mM ammonium sulfate) was added to the cell-hydroxylapatite bead mixture, the rate and extent of adhesion were decreased. Addition of nonpolar p-dioxane (10% [vol/vol], final concentration) to the mixture enhanced binding. This suggests that electrostatic linkages participate in the primary adhesion of streptococci to both substrata. The strongly positive entropy values and the lesser temperature dependence of the saliva-coated hydroxylapatite system suggest that another entropy-driven process is imposed on the electrostatic linkages. This supports a role for hydrophobicity, suggesting that a combination of electrostatic and hydrophobic forces mediate the initial adhesion of S. sanguis to the salivary pellicle.Significant advances have recently been made in the description of cellular adhesion mechanisms. Mammalian (23) and bacterial (6) cells have been shown to adhere through complex interactions with attractive and repulsive forces operating near substrata. Adhesion of streptococci to the salivary pellicle has long been recognized to be a complicated process. From the time of their eruption, teeth are constantly covered with a coating of salivary glycoproteins and proteins (pellicle). This pellicle is the substratum for oral bacterial attachment. Streptococcus sanguis seems to possess some specificity for the pellicle components since it reaches an equilibrium with the substratum. However, that specificity has been difficult to define, and it is believed that multiple forces govern adhesion (10)(11)(12). Kinetic studies suggest that S. sanguis passes through two distinct binding transitions (8). The first stage is a reversible one described by pseudofirst-order rate constants for adsorption and desorption. The cells bound in this equilibrium may then become more firmly attached and have a decreased propensity to desorb in the second phase of the reaction. The proposed mechanism can be represented as Cell + pelliclez±CP*--*CP 1 1 in which CP* represents the first, lower-affinity association between cell and pellicle. The rate constants governing this phase of the reaction are low, suggesting that the initial association is the rate-limiting one. Cells often adhere to solid surfaces in this general sequence. Marine pseudomonads (...

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Surface Free Energy Changes of Human Enamel during Pellicle Formation

Cited by 38 publications

References 16 publications

Wettability modification of human tooth surface by water and UV and electron-beam radiation

Wettability modification of human tooth surface by water and UV and electron-beam radiation

Elemental Surface Concentration Ratios and Surface Free Energies of Human Enamel after Application of Chlorhexidine and Adsorption of Salivary Constituents

Energetics of the initial phase of adhesion of Streptococcus sanguis to hydroxylapatite

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