IN-VITRO INTERACTIONS OF DELMOPINOL HYDROCHLORIDE WITH SALIVARY FILMSADSORBED AT SOLID-LIQUID INTERFACES

Delmopinol hydrochloride is a highly surface active substance which ha s been shown to reduce the amount of plaque in vitro and in vivo and t he level of gingivitis in vivo. Ellipsometry was used to evaluate the effect of delmopinol on films formed from whole, parotid and sublingua l/submandibular saliva on solid surfaces. Hydrophilic plasma cleaned s ilica and methylated hydrophobic substrates were used. The adsorption processes of the salivary proteins and their interactions with delmopi nol were monitored in situ with a Rudolph thin-film ellipsometer. The adsorption of delmopinol on bare substrates without previous salivary adsorption was also investigated and the results indicate that delmopi nol molecules were adsorbed on both hydrophilic and hydrophobic surfac es. When delmopinol interacted with the films formed from the differen t types of saliva an initial increase in the adsorbed amounts was obse rved in the majority of the cases indicating binding to the salivary p ellicles and/or substrate surface. The noted increases were largest fo r the films adsorbed from whole and sublingual/submandibular saliva. A fter rinsing in the system, partial desorption of the salivary films t ook place. It is thus indicated that delmopinol binds to salivary prot eins within the pellicles and alters the cohesive and adhesive propert ies of these films.