Improving some selected properties of dental polyacid-modified composite resins.

Objectives: Polyacid-modified composite resins (compomers) are restorative dental materials that exhibit certain features of traditional dental composites and glass-ionomer cements. The aim of this paper was to develop experimental compomers with enhanced properties, based on adhesive monomers vinyl phosphonic acid and pyromellitic dianhydride glycerol dimethacrylate, and to compare their properties to those of commercially available products.

Methods: Factorial experimental design was employed to optimize both chemical and physical properties.

A clinical assessment of the performance of a sensor to detect crystalline biofilm formation on indwelling bladder catheters.

Objectives: To test the ability of a sensor developed to signal infection by the organisms that generate the crystalline biofilms that encrust catheters, to give an early warning that encrustation was occurring on patients' catheters, as the care of many patients undergoing long-term bladder catheterization is complicated by the encrustation and blockage of their catheters.

Patients And Methods: Twenty patients were followed prospectively for the lifetime of one of their catheters. Sensors based on cellulose acetate/bromothymol blue were placed in the urine-collection bags, which were changed as usual at weekly intervals.

A preliminary study of experimental polyacid-modified composite resins ('compomers') containing vinyl phosphonic acid.

Objectives: The aim of this investigation was to determine the properties of two novel compomers formulated with the monomer vinyl phosphonic acid (VPA). The setting properties, mechanical strength, wear characteristics and fluoride release of two experimental unshaded compomers containing VPA were determined, and compared with the commercial compomer Dyract A (shade C3).

Methods: Two novel compomers were prepared, containing, respectively, 0.

The role of the ionomer glass component in polyacid-modified composite resin dental restorative materials.

In order to model the processes that occur within polyacid-modified composite resin ("compomer") dental restoratives, a series of experiments has been carried out with silanated and silane-free ionomer glass G338, and silanated and silane-free unreactive glass (Raysorb T-4000). In an acid-base reaction with dental grade aqueous maleic acid-acrylic acid copolymer solution, the setting time of the silanted G338 was found to be 9 min, compared with 5 min for the silane-free glass. Inclusion of each glass in an experimental composite resin system showed that the formulations which contained G338 absorbed more water than the formulations which contained Raysorb T-4000, regardless of whether or not the glass was silanted.