title: Zinc polycarboxylate dental cement for the controlled release of an active organic substance: proof of concept.
abstract: The potential of employing zinc polycarboxylate dental cement as a controlled release material has been studied. Benzalkonium chloride was used as the active ingredient, and incorporated at concentrations of 1, 2 and 3% by mass within the cement. At these levels, there was no observable effect on the speed of setting. Release was followed using an ion-selective electrode to determine changes in chloride ion concentration with time. This technique showed that the additive was released when the cured cement was placed in water, with release occurring by a diffusion mechanism for the first 3 h, but continuing beyond that for up to 1 week. Diffusion coefficients were in the range 5.62 x 10(-6) cm(2) s(-1) (for 1% concentration) to 10.90 x 10(-6) cm(2) s(-1) (for 3% concentration). Up to 3% of the total loading of benzalkonium chloride was released from the zinc polycarboxylate after a week, which is similar to that found in previous studies with glass-ionomer cement. It is concluded that zinc polycarboxylate cement is capable of acting as a useful material for the controlled release of active organic compounds.
authors.affiliation: Department of Pharmaceutical, Chemical and Environmental Sciences, School of Science, University of Greenwich, Chatham, Kent, UK.
authors.forename: Mohammad Naseem
authors.initials: MN
authors.lastname: Ali
authors.forename: Mark
authors.initials: M
authors.lastname: Edwards
authors.forename: John W
authors.initials: JW
authors.lastname: Nicholson
mesh_terms: D000891:Anti-Infective Agents, Local / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D001548:Benzalkonium Compounds / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D001672:Biocompatible Materials / Q000737:chemistry / Q000493:pharmacokinetics; D002327:Cariostatic Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D003210:Concept Formation; D003692:Delayed-Action Preparations / Q000138:chemical synthesis / Q000737:chemistry / Q000493:pharmacokinetics; D003738:Dental Cements / Q000138:chemical synthesis / Q000737:chemistry / Q000493:pharmacokinetics; D003799:Dental Stress Analysis; D005899:Glass Ionomer Cements / Q000737:chemistry / Q000493:pharmacokinetics; D008422:Materials Testing; D008954:Models, Biological; D011076:Polycarboxylate Cement / Q000138:chemical synthesis / Q000737:chemistry / Q000493:pharmacokinetics
chemical_list: D000891:Anti-Infective Agents, Local; D001548:Benzalkonium Compounds; D001672:Biocompatible Materials; D002327:Cariostatic Agents; D003692:Delayed-Action Preparations; D003738:Dental Cements; D005899:Glass Ionomer Cements; D011076:Polycarboxylate Cement