J F Perdok

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We measured the surface tension of solutions of five surfactants in water, ethanol, and a 50% water/ethanol mixture at 25 degrees C, as well as the contact angle of these solutions on ground and polished bovine enamel in vitro and on intact pellicle-covered human enamel in vivo. All surfactants lowered the surface tension of water. In ethanol, no reduction(More)
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(More)
Bacterial growth of a vegetable oil-based product was determined in vitro. Growth of Streptococcus mutans and Veillonella alcalescens was strongly inhibited for dilutions up to 50x. On the basis of these results, it was decided to evaluate the short-term, clinical efficacy of a 1:10 dilution of the concentrated product in water. Fifteen human volunteers(More)
The adsorption of active agents from six commercially available mouthrinses to ground and polished enamel, with and without adsorbed salivary constituents, was monitored by contact angle measurements and X-ray Photoelectron Spectroscopy (XPS). Human enamel samples were treated with mouthrinses containing chlorhexidine (Peridex), stannous fluoride/amine(More)
To determine the influence of cetylpyridinium chloride (CPC) adsorption on the wettability and elemental surface composition of human enamel, with and without adsorbed salivary constituents, surface-free energies and elemental compositions were determined. The surface-free energies were estimated from contact angle measurements; whereas the elemental(More)
Slow EEG potentials were recorded during the foreperiod of a signal detection task which involved different levels of discrimination difficulty. The subject was required to react to S2 as quickly as possible or to delay his response by 1 s. It was found that the contingent negative variation (CNV) was attenuated when no speeded response was required and(More)