Plaque-disclosing Composition And Package System

Abstract

A plaque-disclosing formulation suitable for use in aerosol form without causing undue "cold-sensitivity" -related pain to a patient. The formulation comprises a specially selected dye such as Erythrosine B, and an active solvent like ethanol to aid penetration of the dye into the plaque deposit. It is incorporated into an aerosol charge which comprises a Freon-type propellant in a quantity which contributes less than 50 B.t.u. heat of evaporation per pound of total aerosol charge at one atmosphere. It is advantageously packaged in an aerosol-type container equipped with a meter-type valve rated for discharging less than about 70 milligrams per shot. The container should be equipped with a discharge conduit of from 1.5 to 2.5 inches in length and a bore size of from about 0.010 to about 0.03 inches in diameter.

Description

BACKGROUND OF THE INVENTION

A number of diseases of the teeth and/or gums are related to the presence of certain types of bacteria found in the mouth. Tooth decay as manifested by cavities and pyorrhea are common examples of bacteria-caused dental diseases.

The harmful bacteria tend to attach themselves to the teeth and grow into sizeable colonies. These colonies are generally called plaque. The bacteria in these colonies will begin to produce acid within a few seconds after a person eats any food, such as sugar, which is hydrolyzed by enzymes present in the mouth. This acid production will normally continue in and on the bacterial deposit for a considerable time after the sugar has been eaten, causing tooth decay.

Plaque, if not removed from the mouth, will eventually form a relatively hard, tenaciously adherent deposit called calculus or tartar. This calculus deposit itself becomes a favorable environment for the colonization of more bacteria and, consequently, the size of the calculus deposit tends to increase as further layers of plaque form and calcify thereon. Eventually this calculus and plaque cause irritation which leads to infection of the gum tissue. Although the earliest manifestation of such irritation and infection may be bleeding of gum tissue, the infection will eventually reach the bone that supports the teeth and contribute to a progressive loss of the bone support of the teeth and, consequently, to the loss of the teeth.

For these reasons, plaque-control is becoming recognized as a basic requirement of preventive dentistry. It has become recognized that, by frequently removing dental plaque from his teeth, a person will be able to effectively avoid the two most common dental diseases such as tooth decay and pyorrhea.

The growth of plaque and the subsequent buildup of calculus deposits, can be avoided by proper oral hygiene practices which may be carried out by a person on his own teeth. Of course such self-care pre-assumes that a person start with relatively clean teeth, i.e., teeth from which plaque and calculus deposits have been recently cleaned. Such self-care also pre-assumes the ability by the person to identify those portions of his mouth where the plaque is beginning to build up once again. In this connection, it is to be emphasized that plaque is sufficiently adhesive that normal nonlocalized care is ineffective and burdensome to a person wishing to remove plaque from selected locations in his mouth. Unfortunately plaque is difficult to see even on the exposed surfaces of the teeth because it is usually deposited in a colorless and transparent form. Therefore it has been generally regarded to be desirable to use "plaque disclosing" compositions to identify areas of the mouth where plaque buildup is a problem.

Among suggested "plaque disclosing" compositions have been solutions of basic fuschsin dye which have been painted on the tooth surface with cotton applicators. These solutions have the general drawback of being nondiscriminating discriminating in that they tend to stain other parts of the mouth as well as plaque deposits for up to several hours after use. This presents a real problem in terms of acceptance because of the cosmetic problems presented to the user.

Another attempted solution to the problem has been the incorporation of various dyes in chewable wafers. Frequently such wafers do not develop sufficient concentration of dye to stain the plaque deposits. Moreover, the activity of the dye compositions generated in the mouth is so low that the dye does not adequately penetrate the plaque deposit and they are not detected by the user of the wafer. Thus a person can easily be misled into believing he has cleaned the plaque from his teeth when such, in fact, is not the case. It remains a problem, then, to provide people with plaque-disclosing means that can be conveniently and effectively used by people without a detrimental cosmetic effect.

SUMMARY OF THE INVENTION

It is an object of the invention to provide an improved plaque-disclosing means which selectively identifies areas of plaque-formation on all tooth surfaces.

It is another object of the invention to provide an improved plaque-disclosing composition which combines the ability to penetrate plaque deposits and yet is susceptible to relatively easy removal from the mouth by washing and rinsing after use.

Another object of the invention is to provide a novel process for safely and easily applying plaque-disclosing compositions in such a way as to assure the discrimination between plaque-contaminated and plaque-free surfaces.

A further object of the invention is to provide a suitable dispenser for use in the aforesaid process.

Still another object of the invention is to achieve a means for applying a plaque-disclosing composition in a spray form while substantially achieving the above objects, but without causing pain to the patient because of cold-sensitivity of the teeth.

Other objects of the invention will be obvious to those skilled in the art on reading the instant invention.

The above objects have been substantially achieved by the formulation of an improved plaque-disclosing formulation and the incorporation of this formulation in a novel composition suitable for application as an aerosol spray. The aerosol composition comprises a carefully selected propellant which gives adequate spray coverage with a minimum of interference with the plaque-disclosing formulation yet evaporates in such a way as to minimize the discomfort of patients having cold-sensitivity problems.

The plaque-disclosing formulation includes a dye, and a solvent which is adapted to dissolve the dye and to aid the penetration of the dye into the plaque deposit.

The most advantageous dye for use in the plaque-disclosing formulation is selected from those dyes such as Erythrosine B. This dye is an acid red dye of the Xanthene type which is further identified as F.D. & C. Red No. 3 and Dye No. 45430 in the Color Index.

Erythrosine B exhibits a significantly superior performance over such dyes as basic fuchsin which stains so intensively that an excessively prolonged staining effect is realized. Moreover, such dyes as amaranth and Brilliant Blue are excessively water soluble and neither penetrate nor persist in the mouth to the degree desirable for plaque-disclosing purposes.

It has been found that from about 0.5 percent to 10 percent by weight of dyestuff should be used in the plaque-disclosing composition, most advantageously about 1.5 to 3 percent. The balance of the plaque-disclosing composition is the solvent for the dye.

The solvent must, of course, be selected from those that are physiologically tolerable with reference to the particular oral utility of the invention. The solvent must also provide a major portion of a more active component to facilitate the solution of a dye (which must have some resistance to water leaching) and to aid the penetration of the dye into plaque deposits. The use of a physiologically intolerable aliphatic hydroxy compound such as ethanol is particularly advantageous. In addition to this more active component, the solvent should comprise a substantial quantity of water to facilitate removal of the dyestuff from the areas of the mouth where the more active solvent component does not find plaque deposits into which it carries the dyestuff. Other water-soluble, physiologically tolerable solvents such as glycerine can be used although the ethanol-water system gives the best balance between plaque discrimination and dye penetration under most conditions of use.

In summary the plaque-disclosing formulation comprises a dyestuff, a solvent comprising a more active component (or penetrant) such as ethyl alcohol and a less active component such as water. The plaque-disclosing formulation most advantageously used with Erythrosine B is a mixture of aliphatic alcohol, preferably ethanol, and water.

The total aerosol composition comprises a carefully selected propellant to act as a carrier of the plaque-disclosing formulation. This propellant must be carefully selected to avoid causing pain to those patients having what is known to dentists as "cold-sensitivity." To this end, it is advantageous that the propellant have a maximum heat of evaporation of about 50 B.t.u. per pound of total aerosol composition at 1 atmosphere of pressure. It is advantageous for this value-- which is a measure of the cooling capacity of the solvent-- to be much closer to 20 B.t.u. per pound of aerosol composition charge.

The propellant system, of course must be one which lacks toxic characteristics. A particularly advantageous propellant system conforming to the criteria set forth above and selected from the halogen-substituted hydrocarbon-type compounds available from E.I. DuPont de Nemours Company under the trade designation Freon. Among such systems would be a 60:40 mixture of CClF.sub.2 CClF.sub.2 and CCl.sub.2 F.sub.2 or plain CCl.sub.2 F.sub.2 each, of course, taken in an appropriate quantity.

The total propellant forms about 30 to 60 percent of the entire aerosol spray composition with the more advantageous range being from about 30 to 50 percent. The lower quantity reduces the amount of gas which must be dissipated from the sometimes restricted volume adjacent the discharge point.

The means by which the above-disclosed aerosol formulation is delivered to the desired surfaces inside the mouth has been found to be important, not only to allow manipulative convenience in applying the plaque-disclosing solution to a particular tooth surface within the mouth, but also to provide a means to further reduce the cold-sensitivity problem by preconditioning and moderating the precise rate at which the aerosol solution is discharged from the device. In this regard, it has been discovered that single discharges of aerosol composition should be made in quantities of from about 20 to about 70 milligrams with the lower discharges being preferred.

Moreover, the length of the applicator arm and bore therein have been found to provide the most advantageous spray when so designated as to be from about 1.5 inches to 2.5 inches in length and having a bore size of from about 0.010 inch to about 0.03 inch. These bore sizes and length provide a balance between velocity and shape of the spray as it leaves the bore discharge and aid in obtaining not only the desired directional effect but a suitable evaporation of propellant before the spray hits the tooth surface.

ILLUSTRATIVE EXAMPLE OF THE INVENTION

In order to point out more fully the nature of the present invention the following specific example is given as an illustrative embodiment of the present process and products produced thereby.

FIG. 1 is an elevation of the plaque-disclosing package prepared according to the invention.

FIG. 2 is a perspective view of the applicator arm shown in FIG. 1.

FIG. 3 is a section of a fragment of the applicator arm.

FIG. 4 is an elevation of the pivot, showing the sweep of the applicator arm.

EXAMPLE 1

The following aerosol composition was prepared:

% by weight __________________________________________________________________________ Erythrosine B Dye 1.0 Deionized water 11.5 Ethanol solvent * 37.5 Freon 12 (CCl .sub.2 F.sub.2) 20.0 Freon 114 (CClF .sub.2 CClF.sub.2) 30.0 100.00 __________________________________________________________________________

This aerosol composition was charged into an aerosol package 10, as shown in FIG. 1, comprising an Emson ASD-1 valve actuator 11 and a valve system which metered 50 milligrams of material 13 through a 2.25-inch arm 12 having a 0.018-inch bore 14 therein. Arm 12 is fitted with a protective cap 16. The resulting package assembly provides a sealed nonbreakable package which can easily be used to apply the plaque-disclosing composition in a high concentration to a localized and preselected area. Moreover, the container is substantially air free, thereby assuring minimum oxidative degradation of the dyestuff. The velocity imparted by the propellant to the alcohol-dye allowed the instantaneous disclosure of the plaque deposits without risk of "false-negatives" of the type frequently encountered when so-called disclosing-wafers are used.

EXAMPLE 2

The following aerosol charge was prepared:

Parts by wt. __________________________________________________________________________ Erythrosine B Dye 1.5 Deionized water 11.5 SDA 38A solvent 52 Freon 12 35 __________________________________________________________________________

This material had the advantages of the composition disclosed in example 1 except that it was improved with respect to limiting undesirable responses to cold sensitivity because of the lower concentration of propellant. The latent heat of evaporation was only about 24 B.t.u. per lb. of aerosol charge. Therefore the propellant flashed off as it came from the nozzle with minimum of local cooling effect.

It is to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described.

Claims

What is claimed is:

1. A plaque-disclosing aerosol dispenser package equipped with a metering valve and a discharge arm having a bore size and length forming means to provide a suitable evaporation and dissipation of propellent gas before aerosol spray discharged therefrom hits a tooth surface, said package containing a composition comprising (A) Erythrosin B as the essential plaque-disclosing dye, (B) a physiologically tolerable solvent therefore consisting of:

1. a major quantity of plaque-penetrating alcohol and

2. a minor quantity of water in admixture with (C) an effective quantity of nontoxic halogenated hydrocarbon propellant, said propellant contributing not above 50 B.t.u.s of heat of evaporation to each pound of the total aerosol formulation, said composition being substantially free of excessively prolonged and insufficiently persistent plaque-disclosing dyes and being free of propellants contributing sufficient heat of evaporation to cause painful sensation on teeth.

2. A plaque-disclosing composition as defined in claim 1 wherein said dye forms from 0.5 to 10 percent of said composition and said alcohol is ethanol.

3. A plaque-disclosing composition as defined in claim 2 wherein the weight ratio of ethanol:water is at least 2:1 and the dye forms from 1.5 to 3 percent of said composition.

4. A process for the selective disclosure of plaque deposits by aerosol techniques without subjecting a patient to pain caused by localized cooling, said process comprising the steps of spraying a discharge of an effective amount of a dye-bearing solution as defined in claim 1 from the discharge arm of the aerosol dispenser package of claim 1.

5. A process as defined in claim 4 wherein said dye is Erythrosyne B, and wherein said active solvent component is ethanol.

6. A dispenser package as defined in claim 1 useful in the selective disclosure of plaque deposits by aerosol techniques and comprising the plaque-disclosing aerosol formulation in an aerosol dispenser equipped with a metering valve capable of ejecting from about 20 to about 70 milligrams of said formulation per discharge and equipped with a discharge arm of from 1.5 to 2.5 inches in length having therein a conduit bore of from 0.01 inch to about 0.03 inches in diameter.