Denture retaining composition

A composition for retaining dentures in the mouth of a denture wearer including 5-8% w/w of an hydrophilic gelling agent, 2-7% w/w of a thickening agent, 5-20% w/w of ail agent that imparts water resistance to the composition, 0.2-5% w/w of humectant(s) and the balance being water, the composition being formable into a viscous hydrophobic film in use. A method of retaining dentures in the mouth of a denture wearer by applying to the denture or the mouth tissue the composition and placing the denture into position in the mouth in a manner such that the composition substantially forms a seal between the mouth tissue and the denture to thereby assist in the retention of the denture.

TECHNICAL FIELD 
The present invention relates to compositions and methods for holding 
dentures in position in the mouth of a denture wearer. 
BACKGROUND OF THE INVENTION 
The methods currently in use for positioning and holding dentures in the 
mouth are based primarily on applying adhesive compositions to the 
dentures prior to insertion. Such adhesive compositions come in the form 
of adhesive creams or adhesive powders and utilise the stickiness of the 
compositions to hold the dentures in position. 
The denture adhesives available at present have many disadvantages. One of 
the major disadvantages is in the difficulty in the application of the 
material to the denture prior to insertion. The adhesives are often quite 
messy and are awkward to apply and use. This problem is particularly 
significant taking into account the majority of denture wearers are 
elderly. The dexterity, coordination and eyesight are often impaired in 
the elderly and this exacerbates the difficulty in applying present 
denture adhesives to their dentures. This is particularly relevant with 
the powder adhesives as this material has to be sprinkled onto the plate 
of the denture before insertion. This can be a difficult task for the 
elderly and often results in considerable waste of the material due to the 
failure to apply the correct amount to the denture surface. 
Furthermore, the texture of the denture adhesives are often sandy or gritty 
and may cause irritation to the gum and surrounding tissue when used for 
prolonged periods. The majority of the denture adhesives available also 
have a strong taste and this can often be offensive to the wearer. 
As the adhesive materials have the tendency to set hard in order for them 
to achieve their desired function in use, there is a real problem of 
removing the hard material from the dentures, the mouth tissue and 
remaining teeth in the mouth after use. If the denture adhesives are not 
removed completely after use, there is a gradual build-up of the adhesives 
on the dentures which causes further problems of fit and comfort to the 
wearer. Ultimately, this build-up may cause irritation to the dental 
tissues resulting in severe discomfort and pain. There is also the real 
risk of damaging the dentures during harsh techniques often required to 
remove the adhesive build-up. Again, taking into account the proportion of 
the elderly population that wear dentures, this removal process may pose a 
serious problem to them. 
The presently available materials normally act for only up to 12 hours of 
use. If the material is not applied carefully to the dentures the 
appearance of excess material on the dentures is often unsightly. The 
materials are often applied liberally on the plate of the dentures prior 
to insertion and any excess is extruded from out between the dental tissue 
and the plate of the denture when used. The adhesive nature of the 
material often results in the covering of the teeth component of the 
denture with unsightly build-up. 
The main indication of using the adhesives presently available is for loose 
fitting dentures. There are no suitable materials available at present for 
normal fitting dentures that will assist in their retention in the mouth 
for prolonged periods. 
A further disadvantage of denture adhesives presently available is that 
saliva of the denture wearer is required as a lubricant between the oral 
tissues and the denture and/or as a diluent for the adhesive. Denture 
wearers that have reduced saliva production resulting from conditions such 
as diabetes are unable to use successfully these denture adhesives. There 
is a need for a denture retaining composition that does not rely to any 
great extent on the saliva production of the denture wearer for its 
action. 
The alternative to the denture adhesives presently available are cushions 
adapted to be inserted in very loose dentures to fill the gap between the 
denture and the tissue of the mouth. These cushions are also difficult to 
apply to the dentures and have a rough texture that may cause irritation 
to the surrounding dental tissue. Furthermore, a real disadvantage of the 
denture cushions is that they absorb food and odours and therefore are a 
source of oral odour for the wearer. Additionally, they may pose a health 
risk due to the growth of bacteria from the mouth. Consequently the 
denture cushions should only be used for a short period of time, 
approximately six hours. 
The present inventors have realised that there is a need for a better 
denture retaining composition which when in use will address many of the 
problems of the denture retaining materials presently available. 
BRIEF SUMMARY OF THE INVENTION 
Accordingly, in a first aspect the present invention consists in a 
composition for retaining dentures in the mouth of a denture wearer, the 
composition comprising: 
(a) hydrophilic gelling agent; 
(b) thickening agent; 
(c) agent that imparts water resistance to the composition; 
(d) humectant(s); and 
(e) the balance being water; 
the composition being formable into a viscous hydrophobic film in use. 
In a preferred embodiment of the first aspect of the present invention, the 
composition comprises: 
(a) 5-8% w/w of an hydrophilic gelling agent; 
(b) 2-7% w/w of a thickening agent; 
(c) 5-20% w/w of a water resistance imparting agent; 
(d) 0.2-5% w/w of humectant(s); and 
(e) the balance being water. 
In a further preferred embodiment of the first aspect of the present 
invention, the composition comprises: 
(a) 7% w/w of an hydrophilic gelling agent; 
(b) 4% w/w of a thickening agent; 
(c) 10% w/w of a water resistance imparting agent; 
(d) 1% humectant(s); and 
(e) the balance being water. 
When the composition is in the form of an emulsion, the composition 
optionally includes an emulsifier stabilising agent or agents. 
In a still further preferred embodiment of the first aspect of the present 
invention, the hydrophilic gelling agent is alginate or xanthan gum. One 
form of xanthan gum suitable for the present invention is sold under the 
trade name "KELTROL" by Merck & Co, but other similar agents may be used 
for the present invention. 
The thickening agents for the present invention may be in the form of a 
polyacrylamide composition together with non-ionic surfactants. A suitable 
thickening agent for the present invention when the composition is in the 
form of an emulsion is sold under the trade name "SEPIGEL 305" by Bleakley 
Fine Chemicals, Australia. According to the manufacturer "SEPIGEL 305" is 
a polymer substance designated as: polyacrylamide (and) C.sub.13-14 
isoparafin (and) LAURETH-7 (an alkyl poly(ethyleneoxide) consisting of a 
lauryl group and seven repeating ethyleneoxide units). It will be 
appreciated by persons skilled in the art, however, that other thickening 
agents may also be used for the present invention. 
The water resistance imparting agent is preferably a water resistant liquid 
silicone. A suitable liquid silicone suitable for the present invention is 
sold under the trade name "DOW CORNING 200" fluid but other similar 
carrying agents are also suitable for the present invention. The function 
of the water resistance imparting agent is to provide to the composition 
resistance to dispersion by normal salivary processes when in use. 
The humectants suitable for the present invention include propylene glycol 
or similar compounds and the water is preferably purified water. 
The composition of the present invention may further include dye materials 
and preservatives known to the art. These further additives may impart 
colour and taste to the composition, promote the shelf life of the 
composition and prevent microbial growth. 
The composition of the present invention consists of a combination of 
hydrophilic and hydrophobic gelling agents together with vehicles or 
carriers which are adapted to form a viscous hydrophobic film which is 
cosmetically acceptable for use in the mouth. 
It will be appreciated by one skilled in the art that the composition can 
have any viscosity prior to use but the composition should form a viscous 
hydrophobic film in situ so as to substantially form a seal between the 
denture and the mouth tissue. 
The composition of the present invention is not an adhesive agent but acts 
in use as a sealing agent that substantially promotes a seal between the 
dentures and the dental tissue when the dentures are inserted in the 
mouth. Furthermore, as the composition of the present invention retains 
its viscous state and is hydrophobic, after use it can be removed 
relatively easily as it does not adhere to hard tissues in the form of 
natural teeth, soft tissues in the form of gums and mucosa and the denture 
base. After removing the dentures, the denture retaining composition is 
removed from the denture base by wiping with a tissue or the like. The 
composition does not set and therefore there is little problem of 
accumulation of the composition on the dentures due to any difficulty in 
removal as experienced with the dental adhesives in use at present. 
In a second aspect, the present invention consists in a method of retaining 
dentures in the mouth of a denture wearer comprising the following steps: 
(a) applying to the denture or the mouth tissue a composition comprising 
5-8% w/w of an hydrophilic gelling agent, 2-7% w/w of a thickening agent, 
5-20% w/w of an agent that imparts water resistance to the composition, 
0.2-5% w/w of humectant(s) and the balance being water, the composition 
being formable into a viscous hydrophobic film in use; and 
(b) placing the denture into position in the mouth in a manner such that 
the composition substantially forms a seal between the mouth tissue and 
the denture to thereby assist in the retention of the denture. 
When the composition is in the form of an emulsion, the composition 
optionally includes an emulsifier stabilising agent(s). 
In a preferred embodiment of the second aspect of the present invention, 
the composition is applied to the denture and, more preferably, the 
composition is applied around the borders of the denture so as to ensure 
that a substantial seal is made between the mouth tissue and the denture 
when the denture is inserted in the mouth.

DETAILED DESCRIPTION OF THE INVENTION 
In order that the present invention may be more clearly understood, a 
preferred form thereof will be described with reference to the following 
example. 
One example of the composition of the present invention in the form of an 
emulsion is given in Table I. In this example, the hydrophilic gelling 
agent is xanthan gum sold under the trade name "KELTROL F" by Merck & Co. 
The thickening and stabilising agent is in the form of a polyacrylamide 
composition together with non-ionic emulsifiers and is sold under the 
trade name "SEPIGEL 305" by Bleakley Fine Chemicals. The water resistance 
imparting agent is a water resistant liquid silicone sold under the trade 
name "DOW CORNING 200" liquid fluid. The humectant is propylene glycol. 
The composition further comprises a dye and preservatives. 
TABLE I 
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Material % gm Supplier 
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Keltrol F 7.00 70.000 Kelco Australia 
Sepigel 305 
4.000 40.000 Bleakley Fine Chemical 
Dow 200 Fluid - 
10.000 100.000 Dow 
simethicone 
propyl hydroxy- 
0.160 1.600 Bronson & Jacobs 
benzoate 
methyl hydroxy- 
0.040 0.400 Bronson & Jacobs 
benzoate 
F D & C Red No 
0.060 0.600 Hodgsons Dye Agencies 
40 (1% solution) 
Propylene glycol 
1.000 10.000 Bronson & Jacobs 
Purified Water 
77.740 777.400 
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The composition is produced by dissolving propyl and methyl 
hydroxybenzolate in propylene glycol, dispersing the "KELTROL" in water 
with slow stirring over a long period of time until the mixture is lump 
free and dispersing the "SEPIGEL" in simethicone with slow stirring. The 
"KELTROL" in water solution is then combined with the dissolved propylene 
and methyl hydroxybenzolate solution and combining the "SEPIGEL" solution 
with the remaining ingredients and finally adding the red dye. 
The composition according to the present invention is in the form of a 
viscous hydrophobic material having a viscosity of about 500,000 cP. The 
composition is formulated so as to not wash away by the normal salivary 
process when in use. It is preferred but not essential that the denture 
retaining composition is applied in a continuous line around the inner 
borders of the denture so as to promote a substantial seal between the 
denture and the dental tissue in use. It will be appreciated, however, 
that any means of applying the composition prior to insertion of the 
denture would be acceptable. 
The denture retaining composition of the present invention is suitable for 
all denture wearers on a regular or daily basis. In denture wearers, the 
oral tissues and mucosa by their nature under go constant dimensional 
change. This results in most denture wearers regularly suffering from 
problems ranging from mild irritation or discomfort to lack of retention 
from ill-fitting dentures. In addition, newly fitted dentures after tooth 
extraction often cause severe discomfort to the patient. The present 
inventors have developed a denture retaining composition that is 
particularly suitable to provide relief from these conditions and 
problems. 
In order to test and demonstrate the suitability of the present 
composition, an in vivo test was carried out with a male volunteer. The 
volunteer was selected as he wears dentures comprising full maxillary and 
full mandibular dentures having poor retention. The composition of the 
example was applied to the dentures and then the dentures were inserted at 
12.50 am. The dentures were finally removed at 6.00 pm. on the following 
day, representing a usage duration of 29 hours. 
Table II shows the activities of the volunteer while wearing the dentures 
during this test period. It can be seen from Table II that the volunteer 
carried out normal eating and drinking activities throughout the test 
period and loss of retention was recorded after a period of 29 hours of 
use. 
TABLE II 
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Time Composition 
Applied Comments Acitvity 
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1.15 pm (No discharge or loss of 
Egg sandwiches 
retention) 
3.15 pm Hot cup of tea 
5.20 pm Two orange cream 
biscuits 
6.20 pm Sausages (large) peas & 
mashed potatoes 
10.15 pm Hot cup of tea 
10.30 pm Upper denture removed, 
checked, reinserted 
7.00 am Toast & Weetbix 
12.30 pm Sandwiches 
1.00 pm Hot cup of tea 
6.00 pm Loss of retention 
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During the test time of 29 hours, the volunteer felt as though the dentures 
were "a part of him". The volunteer was questioned at half hour intervals 
and at no stage during the test period did the dentures lose retention. 
The volunteer was not aware of any taste or discharge at any time. To 
further test the effectiveness of the composition, the dentures were 
removed twice during the 29 hour period and then reinserted without any 
loss of retention. At no stage was the composition reapplied during the 
times when the dentures were removed. 
The volunteer suffers from violent coughing which further exacerbates the 
problem of retaining dentures in the mouth. The test demonstrated that the 
composition of the present invention is suitable to retain dentures in the 
mouth in a controlled and user-friendly manner. When the present denture 
retaining composition is in use, it is not detectable and therefore 
promotes further confidence in the wearers of dentures. 
Seven additional subjects were studied for their reaction to the use of a 
denture retaining composition according to the present invention. The 
results of this study are summarised in Table III. It can be seen from 
this table that in all subjects the composition improved the fit of their 
dentures. Furthermore, in many of the subjects there was also a marked 
improvement in comfort of wearing their dentures. 
An important aspect of the composition of the present invention is that it 
is adapted so as to be able to substantially promote a seal between the 
mouth tissue and the dentures in use. The composition is suitable for use 
not only with loosely fitting dentures but with all dentures to improve 
comfort. As the composition does not rely or depend on saliva production 
of the wearer as it has inherent lubricating characteristics, it is 
suitable for denture wearers that may have reduced saliva production due 
to old age or medical conditions like diabetes. The composition is not an 
adhesive and therefore reflects a move away from the traditional 
compositions and methods of retaining dentures. 
TABLE III 
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Case Time of 
Study Insertion 
No Denture (hours) Comments 
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1 Full maxillary 
29 Improved denture fit; 
Full mandibular 
29 Improved retention 
2 Full maxillary 
31 Comfortable; Relief from 
Full mandibular 
7.5 denture movement 
3 Full maxillary 
4 Improved denture fit; 
Full mandibular 
4 Prevented denture movement 
4 Full maxillary 
4 Improved denture fit; 
Full mandibular 
4 Comfortable 
5 Full maxillary 
4 Improved denture fit 
6 Full maxillary 
6 Improved denture fit; 
7 Full mandibular 
4.5 Improved denture fit; 
8 Full maxillary 
23.8 Improved denture fit; 
Full mandibular 
23.8 
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It will be appreciated by persons skilled in the art that numerous 
variations and/or modifications may be made to the invention as shown in 
the specific embodiments without departing from the spirit or scope of the 
invention as broadly described. The present embodiments are, therefore, to 
be considered in all respects as illustrative and not restrictive.