GB2428575A

GB2428575A - Two component silicone containing denture support composition

Info

Publication number: GB2428575A
Application number: GB0515638A
Authority: GB
Inventors: Paul Andrew Dickson; Robert Anthony Lucas; Alfred Vincent Spencer
Original assignee: Reckitt Benckiser UK Ltd
Current assignee: Reckitt Benckiser UK Ltd
Priority date: 2005-07-29
Filing date: 2005-07-29
Publication date: 2007-02-07
Also published as: GB0515638D0

Abstract

A denture support composition which is a product of the reaction between a first part and a second part, the first part comprises a transition metal hydrosilylation catalyst, and the second part comprises a silicone having a silicon-hydrogen reactive group; and at least one of the first and second parts further comprises a silicone having an aliphatically-unsaturated reactive group. The silicones are preferably dimethylvinyl terminated dimethylsiloxane and methylhydrogensiloxane. Trimethylated silica is used as a filler.

Description

COMPOSITION

The present invention relates to a composition and method for supporting a denture (i.e. denture plate) within a user's mouth.

Denture wearers usually use fixatives to secure their dentures in place. Denture fixative compositions are widely available, but users encounter various problems with such products. For example many are water-soluble, leading to dissolution of the fixative over time and the dentures become loose. On the other hand, if the dentures are fixed too securely to the mouth, they cannot easily be removed. This can cause problems if, for example, small particles of food become stuck between the denture and the gum causing discomfort: if the denture cannot easily be removed, the discomfort cannot be alleviated. In addition, denture fixative compositions which do not allow easy removal may cause pain as they are pulled away from the mucosal surface to which they have become strongly adhered.

An alternative method of securing dentures within the mouth is to provide an adhesive patch which sticks to both the mouth and the denture surface. For example, US 4503116 describes a dental adhesive device comprising a laminate : .. of webs which are bonded together by thermoplastic Sue ethylene oxide polymer. However such a patch is not always * S S...

effective and provides no comfort benefit to the denture cuts * . 30 wearer. *1SS

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A further problem suffered by denture wearers is that dentures may be illfitting or, when new, may take time to S... S * S...

become comfortable in the mouth. Such problems are especially experienced by new users of dentures. A method sometimes employed by dentists when a person is first supplied with dentures is to provide a permanent cushioning pad which seats them comfortably in the mouth.

However, this is not removable for the first few months, which introduces difficulties and drawbacks.

It is an object of the present invention to overcome or reduce at least one or more of the aforementioned disadvantages of present methods of retaining dentures within a user's mouth.

It is a further object of the present invention to provide for comfortable retention of dentures within a user's mouth.

According to a first aspect of the present invention there is provided a denture support composition, being a product of the reaction between a first part and a second part, the first part comprising a transition metal hydrosilylation catalyst, and the second part comprising a silicone having a silicon-hydrogen reactive group; wherein at least one of the first and second parts further comprises a silicone having an aliphaticallyUnsaturated reactive group. * S. * I S III.

preferably the first part and the second part both * S *5*S comprise an aliphatically-unSatUrated reactive group. S...

* . 30 SS I* preferably at least one part further comprises a silica filler. Preferably both parts comprise a silica filler. S. * * S S

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Any finely divided form of silica can be used as the filler. A preferred silica filler is trimethylated silica.

Preferably the mass ratio of the first part to the second part is at least 0.5:1, preferably at least 0.7:1, most preferably at least 0.9:1.

Preferably of the mass ratio of the first part to the second part is less than 2:1, more preferably less than 1.5:1, most preferably less than 1.1:1.

Preferably the first part of the composition comprises at least 40% of an aliphatically-unsaturated reactive group, more preferably at least 50%, most preferably at least 60%.

Preferably the silicone having an aliphatically unsaturated reactive group is an alkene-substituted polydiorganosiloxane. Preferably it is a polydirnethyl siloxane having silicone-bonded vinyl, allyl or hexenyl groups. Most preferably it is a dimethylvinyl terminated dimethyl siloxane. This compound is known under CAS No. 68083-19-2.

Preferably the first part of the composition of the present invention further comprises a silica filler.

: .. Preferably the silica filler is present in an amount of at $ I. least 10 wt%, preferably at least 15 wt%. Preferably the *IS.

silica filler is present in an amount of less than 50 wt%, *SS.

more preferably less than 40 wt%.

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The first part of the composition of the present invention comprises a transition metal catalyst. Suitable catalysts *SSS

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include those based on platinum or rhodium. Preferably the catalyst comprises platinum. Suitable catalysts include fluoroplatinic acid, platinum acetyl acetonate, complexes of platinous halides with unsaturated compounds such as ethylene, propylene, organovinylsiloxane and styrene, hexamethyldiplatinum, PtC12.PtC13 and Pt(CN)3. Preferred platinum catalysts are complexes of platinum compounds and vinyl siloxanes.

Preferably the catalyst is present in an amount of 5 to 50 ppm, based on the total composition.

The second part of the composition of the present invention preferably also comprises a silicone having an aliphatically-unsaturated reactive group. Preferably this is present in an amount of at least 40% by weight, preferably at least 50% by weight, more preferably at least 60% by weight. Preferably the silicone having an aliphatically-unsaturated reactive group comprises an alkene--substituted polydiorganosiloxane, preferably a polydimethylsiloxane having silicone-bonded vinyl, aryl or hexenyl groups. Most preferably it is dimethylvinyl- terminated dimethyl siloxane. Preferably the silicone having an aliphatically-unsaturated reactive group present in the first part of the composition is that same as that present in the second part of the composition. * S. * , . SI..

Preferably the second part of the composition further S..

comprises a silica filler. Preferably this is present in an amount of at least 10 wt%, more preferably at least 15 : wt%. Preferably this is present in an amount of less than * . wt%, more preferably less than 40 wt%. S... * S *a.

The second part of the composition of the present invention further comprises a silicone having a silicon- hydrogen reactive group. This is preferably an organosiloxane containing silicon-bonded hydrogen atoms.

preferably the organosiloxane containing silicon-bonded hydrogen atoms is dimethyl methyihydrogen siloxane. This compound is known under the CAS No. 68037-59-2.

Preferably the silicone having an Si-H reactive group provides at least 1 wt% of the second part of the composition of the present invention, more preferably at least 2 wt%, most preferably at least 3 wt%. Preferably the silicone having an Si-H reactive group provides less than 10 wt% of the second part of the composition of the present invention, more preferably less than 8 wt%, most preferably less than 7 wt%.

preferably the ratio of the alkene groups present in the composition due to the silicone having an aliphatically- unsaturated reactive group, and the silicon-hydrogen bonds are in the range of 1.5:1 to 1:1.5.

preferably the composition of the present invention consists essentially of a transition metal hydrosilylation catalyst; a silicone having a silicon-hydrogen reactive group; a silicone having an aliphaticallyunsaturated * ,* reactive group; and a silica filler. Optionally it may include minor cosmetic excipients, for example a colorant or flavouring. Preferably the composition does not * S. comprise any further components. S. S * S S * *

When the first part and the second part of the composition are mixed, the catalyst catalyses a hydrosilation reaction between the silicone having an aliphatically-unsaturated reactive group and the silicone having a silicon-hydrogen reactive group.

Preferably the silicone compounds present in the first and second parts before they are mixed have a viscosity in the range of 5 to 60,000 rnm2/second. When the two parts of the composition are mixed, they undergo a large increase in viscosity, due to a crosslinking reaction taking place.

According to a second aspect of the present invention there is provided a method of supporting a denture in position within the mouth using a composition of the first aspect, the method comprising the steps of: a) mixing together approximately equal amounts of the first and second parts of the composition; b) applying the mixed composition to the appropriate denture surface and placing the denture in the desired position within the mouth; and c) allowing the composition to cure in situ over a period of time.

Preferably the period of time over which the composition : , cures in situ, i.e. in the mouth, is less than 1 hour, preferably less than 30 minutes, more preferably less than minutes and most preferably less than 15 minutes.

During this period the user will observe an increase in viscosity. The composition will change from a gel-like material to form a soft elastomeric silicone rubber. I. * * * S * * *StS * * ****

The composition of the present invention provides comfort to the denture wearer. Although the composition of the present invention maintains dentures securely in position within the mouth, it is better termed a denture support or cushioning composition than a denture fixative.

Preferably, once cured, the composition of the present invention is such that the user may easily remove and reposition the dentures if required.

It is a feature of the composition of the present invention that the first part, the second part, and the resultant composition are all waterresistant.

Suitably the composition has a higher affinity with the material from which the dentures are made than it does with the mucosal surface of the mouth. Thus when the dentures are removed, the composition is preferably carried on the dentures and in preferred embodiments little or none of the composition remains within the mouth.

According to a third aspect of the present invention there is provided the use of a composition of the first aspect in order to support dentures within the mouth.

The invention will now be further described with reference : . to the following non-limiting example. * *. * *. * * * a.

Exaiupl e ** First part a. $ * * * * *SSS

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Dimethyl siloxane dimethylvinyl terminated (CAS No. 68083- 19-2) > 60 wt% Trimethylated silica (CAS No. 68909-20-6) 15-40 wt% Platinum catalyst Second part Dimethyl siloxane dimethylvinyl terminated (CAS No. 6808319-2) > 60 wt % Trimethylated silica (CAS No. 68909-20-6) 15-40 wt% DimethylmethylhydrOgen siloxane (CAS No. 68037-59-2) 3-7% The first part and the second part were thoroughly mixed in a 1:1 ratio and then applied to the denture. The denture was positioned in the mouth and cured in situ over a 15 to 30 minute period. This formed an elastomeric rubber which provided comfort and support, and was water resistant. * a. * , . S.* a S. a * I S. * S. * S * a.

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Claims

Claims 1. A denture support composition, being a product of the reaction

between a first part and a second part, the first part comprising a transition metal hydrosilylation catalyst, and the second part comprising a silicone having a silicon-hydrogen reactive group; wherein at least one of the first and second parts further comprises a silicone having an aliphatically-unsaturated reactive group.
2. A denture support composition as claimed in claim 1 wherein both the first part and the second part comprise a silicone having an aliphatically unsaturated reactive group.
3. A denture support composition as claimed in claim 1 or claim 2 wherein at least one of the first or second parts comprises a silica filler.
4. A denture support composition as claimed in claim 3 wherein the silica filler comprises trimethylated silica.
5. A denture support composition as claimed in any preceding claim wherein the silicone having an aliphatically unsaturated reactive group comprises dimethylvinyl terminated dimethyl siloxane. * a. * .
6. A denture support composition as claimed in any preceding claim wherein the silicone having a silicon- hydrogen reactive group comprises dimethyl methyihydrogen siloxane.

S a.
7. A denture support composition as claimed in any preceding claim wherein the transition metal hydrosilylation catalyst comprises a platinum based catalyst.
8. A method of supporting a denture in position within the mouth using a composition as claimed in any preceding claim, the method comprising the steps of: a) mixing together approximately equal amounts of the first and second parts of the composition; b) applying the mixed composition to the appropriate denture surface and placing within the mouth; and c) allowing the composition to cure in situ over a period of time.
9. A method as claimed in claim 8 in which the period of time over which the composition cures in situ is less than minutes.
10. Use of a composition as claimed in any of claims 1 to 7 in order to support dentures within the mouth.
11. A composition, method or use as hereinbefore described, with reference to the example. a

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