REDUCTION RESISTANT HYDROGEL THICKENERS

Abstract

A reductive composition, suitable for the dental industry, which utilizes sodium dithionite may be provided when it is combined with either polyethyloxazoline or polyvinylpyrrolidone. Other dithionite molecules, such as potassium dithionite, may be used. Likewise, the methods described herein may be applied to other reductive agents.

Claims

1. A chemically reductive composition comprising a dithionite molecule interspersed in a gel that further comprises a gelling agent selected from the set of gelling agents consisting of polyethyloxazoline and polyvinylpyrrolidone.

2. The chemically reductive composition of claim 1, the dithionite molecule being chosen from the set of dithionite molecules consisting of sodium dithionite and potassium dithionite.

3. A chemically reductive composition comprising a chemically reductive agent interspersed in a gel that further comprises a gelling agent selected from the set of gelling agents consisting of polyethyloxazoline and polyvinylpyrrolidone.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] To describe the way the above-recited and other advantages and features of the invention can be obtained, a more particular description of the invention briefly described above will be rendered by reference to specific example embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are therefore not to be considered as limiting of its scope, the invention will be described and explained with additional specificity and detail using the accompanying drawings.

[0012] FIG. 1 is a drawing of a sodium dithionite molecule (prior art).

[0013] FIG. 2 is a schematic drawing showing base gel formation.

[0014] FIG. 3 is a schematic drawing showing the addition of the reductive agent top the gel.

[0015] FIG. 4 is a schematic drawing showing the final reductive compound.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0016] Preferred embodiments of the chemically reductive compositions are herein described. It should be noted that the articles “a”, “an”, and “the”, as used in this specification, include plural referents unless the content clearly dictates otherwise.

[0017] In preparation of a gel from reductive agents, particularly the salts of dithionite, it is important to first form a carrier gel (FIG. 2) by combining the thickener 20 into water 10. The salts of dithionite are notoriously unstable in water, so by creating the gel first, the dithionite retains more of its active properties and the whole process is more stable. Once the gel 30 thickens (FIG. 3) the salts of dithionite 40 are added, yielding an active reduction compound 50 (FIG. 4). The salts of dithionite are usually added in powder form and mixed with the carrier gel. It is important to note that either the sodium or potassium salt of dithionite may be used, but the sodium salt is preferred. The preferred thickeners may be chosen from either PVP or polyethyloxazoline, though any later discovered polymeric thickener with equal or superior stability while in contact with dithionite would be considered an equivalent. The gel stability is unexpected as no other thickeners have demonstrated any significant resistance to the reductive capacity of a dithionite in water. However, for best results, it is found that keeping the water content at or below 25% of the gel formulation by weight improves dithionite stability.

[0018] Although the present invention has been described with reference to preferred embodiments, numerous modifications and variations can be made and still the result will come within the scope of the invention. The described embodiments are to be considered in all respects only as illustrative and not restrictive. No limitation with respect to the specific embodiments disclosed herein is intended or should be inferred. Therefore, the scope of the invention is indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.