Anticaries Confectioneries and Oral Health Products

This invention relates to the prevention of dental caries by incorporating small amounts of anticaries agents in confectioneries, such as syrups, candy, and mints, and oral health products, such as mouthwash, lozenges, toothpaste, and toothpowder. The anticaries agents of this invention are effective against oral microorganisms and have been found to inhibit the growth and lactic acid production of these microorganisms.

Heretofore, it has been generally known and accepted that the elaboration of acid through the breakdown or readily fermentable carbohydrates by acidogenic oral bacteria is the primary cause of dental caries. The method or mechanism of dental caries is generally characterized by a decalcification of the inorganic portion of the tooth and is accompanied or followed by a disintegration of the organic matrix. If acids are permitted to form on the tooth surface, or once formed if they are not neutralized or otherwise removed, the demineralization of the tooth will proceed.

Dentifrices and similar preparations applied to the tooth surface and gums have been one means customarily employed in the cleaning of teeth. In addition, certain medicated dentifrices having the ability to inhibit tooth decay and control dental caries have been developed and marketed. The inhibiting agents of choice in such medicated dentifrices include fluorides or amides.

Another means for control of dental caries involves the use of sodium fluoride. This component may be added to drinking water or topically applied to tooth surfaces to provide a systemic effect. Sodium fluoride has been accorded some degree of acceptance in this regard. Still another means for control of dental caries involves the use of antibiotics such as penicillin. Antibiotics have produced some desirable results in control of dental caries; but this means is not without certain disadvantages involving sensitization of the patient which thereby limits its value as a means of control of dental caries.

While numerous means have been proposed as potential candidates for inhibiting or neutralizing acid formation in the oral cavity, it appears that the problem of control of dental caries is much more complex. It has definitely been established that application of conventional dentrifice preparations by the consumer once or twice a day is not sufficient to control dental caries. Control of dental caries ideally requires the application of a substance capable of inhibiting acid-producing bacteria in the oral cavity which substance has prolonged effects. Following introduction of the substance into the oral cavity protection must be provided by inhibiting the degradation process during the periods between applications, if not longer. Conventional dentrifices fail to provide such protection, because these dentrifices and their inhibitory additives are soon washed from the oral cavity. Conventional active ingredients are normally in contact with the acid-producing microorganisms an insufficient period of time to achieve prolonged inhibitory effects.

In an effort to provide more effective anticaries treatments it has been discovered that certain aliphatic aldehydes, dialdehydes, polyaldehydes, and certain phosphorous containing compounds exhibit a marked anticaries effect when incorporated in chewing gum. These chewing gum compositions are the subject of our co-pending patent applications identified as follows: Ser. No. 858,996 filed Sept. 18, 1969, a continuation-in-part of application Ser. No. 750,314 filed Jan. 10, 1969; Ser. No. 855,770, Ser. No. 855,763, and Ser. No. 855,764, all filed Sept. 5, 1969.

The anticaries agents in the chewing gum compositions described in the above patent applications act to inhibit acid forming microorganisms in the mouth during chewing of the gum and for several hours after the gum is discarded. The anticaries chewing gum compositions provide in part a realistic alternative to repeated brushings of the teeth each time food is consumed during the day to neutralize acid on the tooth surface formed by microorganisms normally present in the mouth.

Because the anticaries chewing gum patent applications described above utilize the aldehydes, dialdehydes, and polyaldehydes of this invention as anticaries ingredients in chewing gum the disclosures of the said patent applications are hereby incorporated by reference.

Although a prolonged anticaries effect has been achieved through the use of fluorides as additives in a wide variety of compositions including toothpastes, and drinking water, fluorides primarily act systemically to modify the basic structure of the inorganic portion of the tooth rather than against acid producing microorganisms. Because a systemic action is involved the use of fluoride additives in large quantities may have undesirable side effects such as discoloration of the tooth surface. Fluorides therefore are used in dilute concentrations, which although effective to increase resistance to dental caries do not inhibit the cause of dental caries.

The anticaries chewing gum compositions of our above-identified patent applications achieve the desired prolonged anticaries effect without undesirable side effects when used either as a supplement to regular brushing, or as an alternative when brushing is not possible.

However, it has now been discovered, that the aliphatic monoaldehydes, aldehydes, and polyaldehydes utilized as anticaries ingredients in the chewing gum compositions are capable of broader application, and may successfully be incorporated into a variety of oral health formulations and confectionaries such as sugar syrups, candies, mints, and lozenges. These vehicles introduce effective amounts of the anticaries agents into the mouth, and do not require the mastication associated with chewing gum. When the anticaries agent is released from the vehicle it comes into contact with microorganisms normally present in the mouth, inhibiting bacterial growth and lactic acid production which initiates or is associated with dental caries and pyorrhea.

The use, as anticaries agents, of the following monoaldehydes, dialdehydes, and polyaldehydes is contemplated within the scope of this invention; glyoxal, pyruvaldehyde, glycolaldehyde, d,1-glyceraldehyde, hydroxypropionaldehyde, glutaraldehyde, succinic dialdehyde, 2,4-hexadienal, mesoxalic dialdehyde, 2-hydroxyadipaldehyde, n-hexaldehyde, 2-hexene-1-al, n-heptaldehyde, octanaldehyde, nonanaldehyde, citral, decanaldehyde, undecylic aldehyde, undecylenic aldehyde, dodecyl (lauric) aldehyde, methylnonylacetaldehyde, dialdehyde starch and dialdehyde galactomannan gum.

The preferred anticaries agents specifically utilized in the compositions of this invention are water soluble, low molecular weight, aliphatic mono and dialdehydes such as pyruvaldehyde, glycolaldehyde, d,1-glyceraldehyde, glutaraldehyde and .alpha.hydroxypropionaldehyde, higher aliphatic aldehydes such as oil soluble, monoaldehydes having from 8 to 12 carbon atoms, citral of natural origin, polyaldehydes such as dialdehyde starch and dialdehyde galactomannan gum, and mixtures thereof.

Accordingly, it is an object of this invention to provide anticaries ingredients for compositions intended to be ingested, masticated, dissolved, or otherwise taken into the oral cavity whereby the anticaries ingredients comes into contact with microorganisms normally present in the mouth.

It is another object to provide aldehyde compounds adapted to be utilized as ingredients in a wide variety of compositions normally introduced into the mouth which aldehydes upon contact with lactic acid producing microorganisms act to inhibit the growth and acid production of these microorganisms.

It is still another object to provide oral health products such as mouthwash, toothpaste, toothpowder, lozenges, and confectioneries containing significant amounts of cane or corn sugar which contain an anticaries agent effective against oral microorganisms which are associated with dental caries.

It is still another object to provide an anticaries agent comprising one or more low molecular weight mono or dialdehyde, monoaldehydes having from 8 to 12 carbon atoms and polyaldehydes adapted to be blended, dissolved, or otherwise incorporated as in emulsion or a cationic, water-soluble ingredient in oral health products and confectioneries of all types to inhibit the growth and acid production of oral microorganisms.

It is yet another object to provide confectioneries and other foods with anticaries activity by introducing one or more aldehydes in quantities of up to five percent by weight into dextrose or sucrose syrups or solids normally employed in the formulation of confectioneries such as thin mints, hard candy, taffy, and wafers formed by compression, hot-melt, or molding.

These and other objects will become readily apparent with reference to the following discussion.

In accordance with the above objects, it has been discovered that aldehydes of the class described exhibit excellent inhibition of lactic acid formation and growth of oral streptococci and bacilli. As a result of extensive tests, studies and experimentation, both in vitro and in vivo of these compounds in the vehicles above described, it has been observed that they exhibit excellent inhibition of lactic acid formation and growth of oral microorganisms of the genera, Lactobacillus and Streptococcus and related microorganisms found in the oral cavity. Additionally, it has been observed that these compounds are readily incorporated into the vehicles of this invention and are released therefrom upon entry into the oral cavity in quantities sufficient to provide the level of activity desired for control of dental caries.

The anticaries ingredients of this invention are well known aldehydes, and with the exception of pyruvaldehyde, available in forms of a purity applicable to incorporation in foods. Pyruvaldehyde is obtained as an aqueous distillate or as an aqueous phase from a condensed azeotrope. It is nearly colorless, contains approximately 20 to 60 percent substantially pure pyruvaldehyde and contains less than 0.04 percent formaldehyde. This process is described in co-pending patent application Ser. No. 714,793 filed Mar. 21, 1968, now U.S. Pat. No. 3,607,943, and assigned to the assignee of this invention. Further purification may provide a formaldehyde content of less than 0.02 percent by weight as outlined in co-pending patent application Ser. No. 714,807 filed Mar. 21, 1968 now U.S. Pat. No. 3,657,074, and also assigned to the assignee of this invention.

Tables I, II and III following summarize in vivo evaluations of representative aldehydes. Standard laboratory techniques were used to compile the data presented. In each case the aldehyde was incorporated into each specimen's food in a one percent, by weight, quantity, over a period of several weeks. In all cases, caries reduction was noted. As tabulated in Tables I, II and III, each of the aldehydes tested exhibited significant reduction in both the incidence of dental caries and the extent of dental caries in laboratory animals.

The aldehydes tested in vivo were pyruvaldehyde, d,1-glyceraldehyde, crystalline dimer, glycolaldehyde, octanaldehyde, nonanaldehyde, decanaldehyde, undecylenic aldehyde, and lauric aldehyde. The polyaldehydes tested were dialdehyde starch, dialdehyde starch 50 percent oxidized, dialdehyde starch 90 percent oxidized, and dialdehyde galactomannan gum.

Two types of in vitro evaluations of the anticaries agents of this invention were conducted. Tables IV - XII summarize anticaries activity in the form of acid production inhibition and growth inhibition of the anticaries agents of this invention employed against Streptococcus or Lactobacillus organisms, or against mixed oral organisms from human subjects. The data was compiled through well-known broth tube analysis techniques.

Tables IV - VII summarize the acid production inhibition against specific strains and against mixed oral organisms of varying concentrations of pyruvaldehyde, d,1-glyceraldehyde, glycolaldehyde, and mixtures thereof. Table VIII summarizes the anticaries activity of glycolaldehyde dimer, pyruvaldehyde, propionaldehyde, .alpha.-hydroxypropionaldehyde, .beta.-hydroxypropionaldehyde, and d,1-glyceraldehyde.

Tables IX - XI summarize the anticaries activity of aliphatic C.sub.6 - C.sub.12 monoaldehydes. Tables IX and X illustrate the activity against specific strains of oral microorganisms while Table XI illustrates the activity of 2,4-hexadienal against mixed oral microorganisms. Table XII summarizes the activity of di and poly aldehydes against specific strains of Lactobacillus and Streptococcus acid-producing microorganisms.

Other in vitro evaluations utilized a broth tube analysis of representative anticaries aldehydes incorporated in the vehicles of this invention against cultures of acid producing microorganisms normally present in the mouth. Tables XIII - XIX summarize the results thereof. Standard laboratory procedures were utilized throughout to evaluate the acid production inhibition and growth inhibition over the incubation time of up to 24 hours.

In formulating Tables XIII - XIX representative aldehydes having anticaries activity were selected from those tested as summarized in Tables I - XII and incorporated in seven representative types of products. The products included dextrose and sucrose syrups, obtained commercially in food grades, and compressed candy, hard candy, mouthwash, toothpaste and toothpowder. The five latter products also employed food grade and reagent grade ingredients. These products were formulated by well-known and representative recipes for each type of product. The products were formed in batches of approximately 1 pound or 1 liter and contained all their normal constitutents. Aliquots of each products were blended with one of each of the representative aldehydes selected except in the case of hard candy.

It should be understood that the use of one or more aldehydes which exist in dimeric or polymerized and hydrated forms are particularly suited to use in hard candy compositions at high temperatures. For example, volatilization and oxidative degradation would be minimized by the chemical structure of glycolaldehyde and pyruvaldehyde. For this reason pyruvaldehyde was used as a representative ingredient in the hard candy tested.

Aliquots of the aldehyde incorporating sugar syrups, confectioneries, and mouthwash formulations were added directly to assay flasks and mixed or dissolved as required. Aqueous extracts of the aldehyde incorporated in toothpaste and toothpowder were prepared and aliquots of the filtrate were added to the assay flasks.

The assay flasks contained the necessary components for a normal growth response from the organisms employed, Lactobacillus casei ATCC 4646, originally a human oral isolate, Streptococcus spp. Kl-R, human caries isolate, and a mixed oral microbial population obtained fresh from saliva on the morning prior to the initiation of each assay incubation period. The assay flask medium was dissolved in distilled water in which was added an equal volume of filter sterilized human saliva to yield a 50 percent saliva-medium combination. The medium contained all normal ingredients such as yeast extract, proteose peptone number 3 (a proprietary formula of Difco Laboratories, Detroit, Michigan) monopotassium phosphate, Tween 80 (polyoxethylene sorbitan monoleate) and water, except a carbon source. This was supplied by the aliquot of the sucrose syrup, dextrose syrup, sucrose in the compressed candy tablet and sucrose in the hard candy product. In addition, an aliquot of sucrose solution concentrate was added to the assay flask as a carbon source for evaluation of mouthwash, toothpaste, and toothpowder vehicles.

Sucrose syrup was prepared from cane sugar and was a 60 percent aqueous solution. The dextrose syrup was a light corn syrup containing about 37 - 38 percent dextrose equivalent.

The following examples list the recipes utilized to formulate vehicles for the anticaries compounds of this invention. The aldehydes of this invention were then incorporated in the vehicles and in vitro anticaries activity was evaluated as summarized in Tables XIII - XIX.

The mixture was cooked to 290.degree. F. and poured into an oiled tray Pyruvaldehyde was added with stirring when the temperature of the batch reached 230.degree. F. and before pouring and solidification of the composition.

The aldehyde ingredient was added in place of an equivalent amount of water in this and subsequent examples.

The quantity of water in relation to glycerol was found to be critical in the preparation of the toothpaste. Excess water results in a slurry, rather than a paste, with insufficient body.

The lower aldehydes such as glycolaldehyde, crystalline dimer; pyruvaldehyde, aqueous syrup; d,l-glyceraldehyde solution and crystalline dimer; and glutaraldehyde, employed as a 50 percent aqueous solution, are water soluble and were employed directly either as powders or aqueous solutions. The C.sub.8 to C.sub.12, longer chain aliphatic aldehydes, of which decyl and dodecyl (lauric) were selected as representative, are oil soluble and are prepared and added to the products as emulsions with four parts of Tween 20, polyoxethylene sorbitan monolaurate. The aldehyde concentrations in the products were randomly chosen between 1 and 5 percent by weight. Limits for the concentrations were selected to coincide with the data presented in Tables I - XII in order to verify that the anticaries activity of the aldehydes in the product vehicles tested was equivalent to the activity previously established for the aldehydes alone.

In summary, Tables I and II above show pyruvaldehyde, d,1-glyceraldehyde, and glycolaldehyde exhibit significant anticaries effects when incorporated in the diet of laboratory animals at a one percent level. Tables IV - VII also show that pyruvaldehyde, d,1-glyceraldehyde, and glycolaldehyde alone or in combination exhibit excellent acid production inhibition in oral microorganisms. Table VIII shows that based on in vitro tests .alpha.hydroxypropionaldehyde also exhibits excellent anticaries activity.

Table II shows octanaldehyde, nonanaldehyde, decanaldehyde, undecylenicaldehyde, and lauric aldehyde exhibit significant anticaries activity when incorporated at a one percent level in the diet of laboratory animals. Tables IX - XII verify that the C.sub.8 - C.sub.12 aliphatic aldehydes exhibit excellent anticaries activity based upon in vitro tests against oral microorganisms. The C.sub.6 and C.sub.7 aldehydes, n-hexaldehyde, 2-hexene-1-al, 2,4-hexadienal, and n-heptaldehyde exhibited excellent acid production inhibition, but little or no growth inhibition in the oral microorganisms.

Table III shows that on the basis of in vivo testing with laboratory animals polyaldehydes such as dialdehyde starches and polysaccharide gums, specifically Dasol A, dialdehyde starch 50 percent oxidized, dialdehyde starch 90 percent oxidized, and dialdehyde galactamannan gum exhibit significant anticaries reduction when incorporated into the diet of laboratory animals at a one percent level. Table XII verifies the acid production inhibition on the basis of in vitro broth tube assays involving cultures of oral microorganisms.

The effectiveness of the representative aldehydes incorporated in representative product types at concentrations of from 1 to 5 percent is illustrated in Tables XIII - XIX. The tables show that the aldehyde compounds of this invention exhibit a significant degree of growth and acid-production inhibition of oral microorganisms during the 24-hour incubation period.

It should be noted that the data contained in Tables XVII, XVIII, and XIX presented difficulties in that the oral health products utilized as vehicles also contain other materials such as flavor oils and ethyl alcohol which also inhibit acid-production of bacteria. Although the culture strains tested were significantly inhibited by the products tested, the effect attributable to the aldehyde ingredients was not readily isolated. However, on the basis of all tests presented, the aldehydes exhibit a significant and prolonged anticaries activity, such that the results in Tables XVII, XVIII, and XIX merely confirm that this activity is not neutralized and their anticaries activity otherwise dissipated when the aldehydes are incorporated in commercial oral health product formulations.

The invention as presented comprises the use of aliphatic mono and dialdehydes having from two to six carbon atoms, aliphatic monoaldehydes having from six to twelve carbon atoms, polyaldehydes such as dialdehyde starch and dialdehyde galactomannan gum, and mixtures thereof as ingredients in oral health products and confectionery foods to impart a prolonged anticaries activity to these products and foods. The anticaries aldehydes of this invention have been found to significantly inhibit the growth and/or acid-production of oral microorganisms. The use thereof has been found to significantly reduce the incidences and extent of dental caries.

It is contemplated that the aldehydes actually utilized to compile the data in Tables XIII - XIX are representative of the aldehydes tested in Tables I - XII. It is intended that the products tested are illustrative of oral health products and confectionery foods generally. Accordingly, this invention is not intended to be limited to the product formulations utilized or those aldehydes shown to have anticaries activity which were actually incorporated in the illustrative products for testing purposes, but limited only by the following claims.