The effect on a water-activated glass poly (alkenoate) dental cement of replacing the water with methanol, 50/50 water/methanol or 50/50 water/HEMA has been studied. The presence of the organic compounds caused the setting reaction to be substantially slowed down, and the resulting cements to be sig
Studies in the setting of polyelectrolyte materials
โ Scribed by H. M. Anstice; J. W. Nicholson
- Publisher
- Springer
- Year
- 1995
- Tongue
- English
- Weight
- 279 KB
- Volume
- 6
- Category
- Article
- ISSN
- 0957-4530
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โฆ Synopsis
The setting behaviour and compressive strengths of zinc polycarboxylate and glass polyalkenoate dental cements activated with sodium chloride solutions of different concentrations and also with artificial saliva have been studied. The results show that the effect of sodium chloride in these cements is concentration dependent. Saturated brine so increased the speed of set of the zinc polycarboxylate that the cement became impossible to mix. Conversely, while having little effect on the speed of setting of the glass polyalkenoate, saturated brine caused the compressive strength to fall to 18 MPa (from 85 MPa with pure water). Neither of the low-concentration solutions (i.e. 0.154 M NaCI or artificial saliva) showed any significant effects on the strength of either cement but both were found to speed up the rate of the setting reaction slightly and to sharpen the set. This effect was too slight to be a source of serious practical concern when these materials are used in clinical dentistry.
๐ SIMILAR VOLUMES
Water-activated versions of zinc polycarboxylate and glass-polyalkenoate dental cements have been used in a study of the effect of electrolytes on setting behaviour and properties. In addition to pure water, 1 M solutions of NaCI, NaF, Na2SO4 and NaNO3 have been used to activate setting. The setting
Specimens of zinc polycarboxylate dental cement have been prepared from aqueous solutions of citric, lactic and ( +)-tartaric acid respectively, and the effect of these acids on the setting characteristics and compressive strength determined. All three acids are stronger than poly(acrylic acid) yet,
## Setting of dental polyelectrolyte cementsviscosity studies of model systems In order to gain information on the setting ot dental cements, the influence of Ca'+, Mg'+, Zn2+, and A13+ ions on the viscosity 0 1 concentrated solutions of partly neutralized pol!r(carboxylic acids) has been measured