The present invention relates to a disposable absorbent articles like sanitary napkins and pantiliners having a peroxyacid for controlling odors associated with body fluids. The disposable absorbent article includes a liquid pervious topsheet, a backsheet, an absorbent core intermediate to the backsheet and said topsheet and a peroxyacid. One of the peroxyacids utilized in the disposable absorbent article is epsilon-pthalimido peroxyhexanoic acid.

This invention relates to articles, such as absorbent articles, for controlling odour, especially the odour associated with bodily fluids, comprising, as the odour control material, the particular peroxyacids as defined herein, and to the use of these peroxyacids as defined herein after as an odour control material.
Malodours may be present in the environment from numerous sources both animate and inanimate. Many products and articles are available which aim to avoid or minimise the detection of such odours. In particular, it is particularly desirable to provide odour control materials to address the malodours which are generated by the human body, or from bodily fluids such as perspiration, urine, faeces, menstrual fluids, vaginal fluids and the like.
Articles like absorbent articles for example are designed to be worm by humans to absorb bodily fluids, such as urine, menstrual fluid and perspiration, etc. Examples of absorbent articles include sanitary napkins, pantiliners, disposable diapers, incontinence pads, tampons, perspiration pads, and the like.
In use, the absorbent articles are known to acquire a variety of compounds, for example volatile fatty acids (e.g. isovaleric acid), ammonia, amines (e.g. triethylamine), sulphur containing compounds (e.g. mercaptans, sulphides), alcohols, ketones and aldehydes (e.g., furaldehyde) which release unpleasant odours. These compounds may be present in the bodily fluid or may be developed by chemical reactions and/or any fluid degradation mechanisms once the bodily fluid is absorbed into the absorbent article like for example a feminine pad. In addition bodily fluids usually contain microorganisms and/or enzymes that can also generate malodorous by products as a result of degradation mechanisms like putrefactive degradation, acid degradation, proteins degradation, fat degradation and the like. Unpleasant odours which emanate from absorbent pads when in use may make the wearer feel self conscious.
Various odour control materials have been disclosed in the art to combat some of the unpleasant odours referred to above. Indeed solutions have been provided that use different technical approaches like masking, i.e., covering the odor with a perfume, or absorbing the odour already present in the bodily fluids and those generated after degradation, or preventing the formation of the odour.
Most of the focus in the prior art is found on the odour absorption technology. Examples of these types of compounds include activated carbons, clays, zeolites, silicates, absorbing gelling materials, starches, cyclodextrine, ion exchange resins and various mixture thereof as for example described in EP-A-348 978, EP-A-510 619, WO 91/12029, WO 91/11977, WO89/02698, and/or WO 91/12030. All of these types of odour control agents are believed to control odour by mechanisms whereby the malodorous compounds and their precursors are physically absorbed by the agents and thereby hinder the exit of the odour from articles like absorbent articles. However, such mechanisms are not completely effective as the formation of the odour itself is not prevented and thus odour detection is not completely avoided.
Thus although these materials provide some control of odours associated with bodily fluids, there still exists a need of further improvement in terms of odour control on a wide range of malodorous compounds.
It is an object of the present invention to provide effective odour control over a wider range of malodorous compounds. More particularly, it is an object of the present invention to provide articles, especially disposable absorbent articles, which deliver a broader spectrum of odour control mainly by preventing the formation of malodours.
It has now been found that the above needs can be addressed by using a peroxyacid, preferably xcex5-phtalimido peroxyhexanoic acid (PAP) as the odour control material for an article, preferably a disposable absorbent article.
By the present invention it has been surprisingly discovered that the use of the peroxyacids of the present invention in an article, like an absorbent article coming into contact with bodily fluids, results in significant decrease of bodily odour, as compared to the same article without the odour control material according to the present invention. Indeed, it is speculated that the peroxyacids according to the present invention have a dual odour control mechanism: they are able to prevent the generation of odour by blocking enzymatic and/or microbial activity as well as to combat the odours already present by oxidising them into no-smelling molecules.
Indeed in contrast to the use of some inorganic peroxides like persulfate or percarbonate, the peroxyacids as described herein are free of deactivation by catalase and/or peroxidase enzymes that are present in bodily fluids. Thus, the peroxyacids according to the present invention are able to keep/retain their oxidizing capacity to oxidise oxidable malodorous compounds into no-smelling compounds.
An additional advantage of the peroxyacids described herein is that the generation of malodorous smelling by products like chlorine derivatives and ammonium derivatives is avoided, when they come into contact with bodily fluids. Indeed, in contrast to the peroxyacids described herein other oxidants like persulphate, periodate, percarbonate, and/or perborate oxidize the chlorides usually present in bodily fluids like menstruation into chlorine derivatives that are not acceptable from the consumer from an odour point of view. Also in contrast to the peroxyacids described herein other oxidants like urea peroxides, calcium peroxides, strontium peroxides and/or barium peroxides (i.e., compounds having an alkaline pH) promote the formation of malodours ammonia derivatives, one of the by products of proteins degradation occurring in, the bodily fluids when they come into contact therewith.
A further advantage associated with the peroxyacid according to the present invention is that it also provides the absorbent article into which it has been incorporated with a better feeling and more acceptable cleanness level. Indeed, the present invention provides an absorbent article capable of changing the color of the menstruation (red blood color) to a pale red color and even to a whitish color.
It is yet another advantage of the present invention that the peroxyacid used herein as the odour control material, ensures prolonged shelf life time of the absorbent article where it is contained in comparison to other oxidants like alkali metal peroxides (e.g., sodium, potassium, lithium, cerium peroxides) and/or superoxide salts (e.g., sodium , potassium, rubidium, cerium, calcium, strontium, barium superoxides). Indeed, it has been surprisingly found that the peroxyacid as described herein present in the absorbent article of the present invention does not react readily with carbon dioxide or vapour air, and thus retains its whole ability to control malodour for a prolonged period of time, up to the time when the absorbent article is used, i.e., comes into contact with bodily fluids.
Whereas the present invention is preferably directed to absorbent articles like pantiliners, feminine napkins, incontinent pads, diapers, tampons, interlabial pads, perspiration pads, surgical pads, breast pads and the like, other articles may include the peroxyacids as described herein too for the purpose of effective odour control. Indeed, other applications include other articles designed to be worn in contact with the body such as clothing, bandages, thermal pads, acne pads, cold pads, compresses, surgical pads/dressings and the like, body and household cleansing articles like impregnated wipes (e.g. baby wipes, wipes for feminine intimate hygiene), impregnated tissues, towels, articles for absorbing perspiration such as shoe insoles, shirt inserts, carpets and the like, and articles for animals like litters and the like.
U.S. Pat. No. 4,363,322 discloses deodorising and disinfecting liquid-absorbing products such as a sanitary napkin, a compress or a diaper, comprising a liquid absorbing material and inside the product at a distance from its outer edges a substance which gives off oxygen in contact with moisture like peroxides, ozonides, superoxides, oxo-ozonides and the like. This reference does not disclose the peroxyacids according the present invention, let alone the odour controlling benefit associated thereto.
The present invention relates to an article, preferably a disposable absorbent article, for controlling odour, preferably the odour associated with bodily fluids, comprising a peroxyacid according to the formula:
R-CO3H
wherein R is a substituted or unsubstituted, saturated or unsaturated, linear or branched hydrocarbon group having from 1 to 25 carbon atoms or a cyclic group having from 3 to 32 carbon atoms and optionally at least one hetero atom (Preferably an heterocyclic group) or a cyclic alkyl group having from 4 to 32 carbon atoms and optionally at least one hetero atom (preferably an heterocyclic alkyl group) or a mixture thereof.
The present invention also encompasses the use as an odour control material of a peroxyacid according to the above formula.
The articles according to the present invention, for controlling odours, especially odours associated with bodily fluids, comprise as an essential element a peroxyacid according to the formula described herein after.
As used herein xe2x80x9codorxe2x80x9d and xe2x80x9codourxe2x80x9d have the exact same meaning as known to those skilled in the art.
By xe2x80x9carticlexe2x80x9d it is meant herein any tridimentional solid material being able to receive/carry a peroxyacid as described herein after. Preferred articles according to the present invention are disposable absorbent articles that are designed to be worn in contact to the body of a user and to receive fluids discharged from the body, such as disposable absorbent pantiliners, sanitary napkins, catamenials, incontinence inserts/pads, diapers, tampons, interlabial pads/inserts, breast pads and the like. Other articles suitable according to the present invention also include other articles designed to be worn in contact with the body such as clothing, bandages, thermal pads, acne pads, cold pads, compresses, surgical pads/dressings and the like, articles for absorbing perspiration such as shoe insoles, shirt inserts, perspiration pads and the like, body and household cleansing articles like impregnated wipes (e.g. baby wipes, wipes for feminine intimate hygiene), impregnated tissues, towels, and the like, and articles for animals like litters and the like.
By xe2x80x9cbodily fluidsxe2x80x9d it is meant herein any fluids produced by human or animal body occurring naturally or accidentally like for instance in the case of skin cutting, including for instance perspiration, urine, menstrual fluids, faeces, vaginal secretions and the like.
The peroxyacids to be used herein are according to the following formula:
xe2x80x83R-CO3H
wherein R is a substituted or unsubstituted, saturated or unsaturated, linear or branched hydrocarbon group having from 1 to 25 carbon atoms or a cyclic group having from 3 to 32 carbon atoms and optionally at least one heteroatom or a cyclic alkyl group having from 4 to 32 carbon atoms and optionally at least one heteroatom.
Typically R is a substituted or unsubstituted, linear or branched alkyl group or alkenyl group having from 1 to 25 carbon atoms, more preferably from 1 to 14 carbon atoms, even more preferably from 3 to 10, and most preferably from 4 to 6. R may also typically be an aryl group having from 3 to 32 carbon atoms, preferably from 3 to 25, more preferably from 6 to 20, even more preferably from 8 to 15 carbons atoms, or an aryl alkyl group having from 4 to 32 total carbon atoms, preferably from 4 to 25, more preferably from 6 to 20 and even more preferably from 8 to 13, or an heterocyclic group containing from 3 to 32 carbon atoms, preferably from 3 to 25, more preferably from 3 to 20 carbon atoms, even more preferably from 5 to 15 and from 1 to 5 hetero atoms, preferably 1 to 3, wherein the hetero atoms are independently selected from the group consisting of oxygen, nitrogen and sulfur, and preferably is nitrogen or oxygen, or an heterocyclic alkyl group containing from 4 to 32 total carbon atoms, preferably from 4 to 25, more preferably from 4 to 22, even more preferably from 6 to 18 and from 1 to 5 hetero atoms, preferably 1 to 3, wherein the hetero atoms are independently selected from the group consisting of oxygen, nitrogen and sulfur, and preferably is nitrogen or oxygen.
The preferred peroxyacids according to the present invention are those wherein R is a cyclic group or cyclic alkyl group, preferably a heterocyclic group or heterocyclic alkyl group.
Even more preferred herein are the peroxyacids according to the following formulae:
or
wherein Ra is a substituted or unsubstituted, saturated or unsaturated, linear or branched hydrocarbon group having from 1 to 14 carbon atoms, Y is an heteroatom and X are substituents in position ortho or meta independently selected from the group of hydrogen, hydroxy, halogen, carboxy, aliphatic saturated or unsaturated, linear or branched, hydrocarbon group having from 1 to 10 carbon atoms.
Preferably Ra is a substituted or unsubstituted, linear or branched alkyl group or alkenyl group having from 2 to 12 carbon atoms, preferably from 2 to 10, more preferably from 2 to 8, even more preferably from 3 to 6 and most preferably 5 carbon atoms. Preferably Y is an heteroatom selected from the group consisting of oxygen, nitrogen and sulfur, and more preferably is nitrogen atom ( greater than N-). Preferably X are substituents on position ortho or meta independently selected from the group consisting of hydrogen, hydroxy, aliphatic linear or branched alkyl group or alkenyl group having from 1 to 10 carbon atoms, preferably from 2 to 7 and most preferably from 3 to 5 carbon atoms. Highly preferred herein all the substituents X are independently hydrogen.
The preferred peroxyacids for use according to the present invention are phthalimido and phtalamido peroxyalkanoic acids.
Highly preferred herein is E-phthalimido peroxyhexanoic acid which may be commercially available from AUSIMONT under the name PAP, or EURECO 0 (in granule form), Eureco WKC (in wet granule form) or Eureco, HC (in powdered active form).
It has now surprisingly been found that the peroxyacids according to the present invention provide significant odour control capacity, especially versus odour associated with bodily fluids. It is speculated that this benefit is due to a dual mechanism: Firstly they can prevent the generation of the odour by blocking the microbial and/or enzymatic activity. Indeed it is speculated that the peroxyacids as described herein oxidize sensitive sulphidryl and sulphur bonds typically present in enzymes, thereby deactivating the enzymes which otherwise would have contributed to the normal metabolism of the micro-organisms like microbes. It is further speculated that the peroxyacids oxidize double bonds in other metabolites like for instance nutriments (e.g., unsaturated fat) for the micro-organisms, thereby rendering these nutriments inefficient for the microbial growth which otherwise would have resulted in generation of malodorous compounds. It is further believed that the peroxyacids described herein disrupt the chemiosmotic function of the lipoprotein cytoplasmatic membrane of the microbe/bacteria cells and thus disrupt the transport function at the cell walls. This later disruption is especially noticeable with the hydrophobic peroxyacids described herein, like the cyclic or cyclic alkyl peroxyacids namely the ones according to the chemical formulae described herein before. Indeed it is speculated that the heterocyclic group or heterocyclic alkyl group according to the preferred peroxyacids herein are able to better react with the lipoproteins of the cell wall of the micro-organisms.
Secondly the peroxyacids as described herein are able to combat the malodorous compounds already present by oxidising them into non-smelling compounds.
A further important advantage associated with the peroxyacids according to the present invention is that they also provide the absorbent article into which they have been incorporated with a better feeling and more acceptable cleanness level. Indeed, the presence of the peroxyacids according to the present invention provides absorbent articles with controlled odor capacity when the menstruation comes into contact with the article, but also absorbent articles being capable of changing the color of the menstruation (red blood color) to a pale red color and even to a whitish color.
Typically, the articles like disposable absorbent articles comprise the peroxyacid or a mixture thereof at a level of from 1 gmxe2x88x922 to 250 gmxe2x88x922, preferably from 5 to 150 gmxe2x88x922, more preferably from 10 gmxe2x88x922 to 100 gmxe2x88x922 and most preferably from 20 gmxe2x88x922 to 70 gmxe2x88x922.
The articles according to the present invention preferably further comprise on top of the peroxyacid described herein before, other conventional agents or mixtures thereof.
For instance additional odour control agent or combinations thereof, known in the art for this purpose may be used herein. These agents can typically be classified according to the type of odour the agent is intended to combat. Odors may be chemically classified as being acidic, basic or neutral.
Alternatively, the odor control agents may be categorised with respect to the mechanism by which the malodor detection is reduced or prevented. For example, odor control agents which chemically react with malodorous compounds or with compounds which produce malodorous degradation products thereby generating compounds lacking odor or having an odor acceptable to consumers may also be utilized herein.
Suitable odor control agents for use herein typically include carbonates (e.g., sodium carbonate), bicarbonates (e.g., sodium bicarbonate), phosphates (e.g., sodium phosphate), sulphates (e.g., zinc and copper sulphates), carboxylic acids such as citric acid, lauric acid, boric acid, adipic acid and maleic acid, activated carbons, clays, zeolites, silicas, absorbent gelling materials (AGM) and starches. Such odor control agents and systems are disclosed in more details hereinafter and for example in EP-A- 348 978, EP-A- 510 619, WO 91/12029, WO 91/11977, WO 91/12030, WO 81/01643 and WO 96/06589.
Suitable odour control agents also include chelating agents and may be selected from amino carboxylates such as for example ethylenediamine- tetracetate, as described for example in U.S. Pat. No. 4,356,190, amino phosphonates such as ethylenediaminetetrakis (methylene-phosphonates), polyfunctionally-substituted aromatic chelating agents as described in U.S. Pat. No. 3,812,044 and mixtures thereof. Without intending to be bound by theory it is believed that the benefit of these materials is in part due to their exceptional ability to remove iron, copper, calcium, magnesium and manganese ions present in the absorbed fluids and their degradation products by the formation of chelates.
Another suitable odor control agent for use herein is a buffer system, such as citric acid and sodium bicarbonate, sodium phosphate and sorbic acid buffer systems. Also, buffer systems having a pH of from 7 to 10 as described for example in WO94/25077 may be useful herein.
Alternative odor control agents are ion exchange resins such as those described in U.S. Pat. No. 4,289,513 and U.S. Pat. No. 3,340,875.
Masking agents such as perfumes may also be used as odor control agents herein.
Typically, the articles like disposable absorbent articles may comprise the odour control agent or a mixture thereof at a level of from 0.5 gmxe2x88x922 to 600 gmxe2x88x922, preferably from 5 to 500 gmxe2x88x922, more preferably from 10 gmxe2x88x922 to 350 gmxe2x88x922 and most preferably from 20 gmxe2x88x922 to 200 gmxe2x88x922.
As is well-known from recent commercial practice, absorbent gelling materials (sometimes referred to as xe2x80x9csuper-sorbersxe2x80x9d) are becoming broadly used in absorbent articles. AGM""s are materials which have fluid-absorbing properties.
Such materials are highly preferred herein as the optional odor control agent due to their dual function of absorbing fluids and odors.
Such materials form hydrogels on contact with water (e.g., with urine, blood, and the like). One highly preferred type of hydrogel-forming, absorbent gelling material is based on polyacids, especially polyacrylic acid. Hydrogel-forming polymeric materials of this type are those which, upon contact with fluids (i.e., liquids) such as water or body-fluids, imbibe such fluids and thereby form hydrogels. These preferred absorbent gelling materials will generally comprise substantially water-insoluble, slightly cross-linked, partially neutralized, hydrogel-forming polymer materials prepared from polymerizable, unsaturated, acid-containing monomers. In such materials, the polymeric component formed from unsaturated, acid-containing monomers may comprise the entire gelling agent or may be grafted onto other types of polymer moieties such as starch or cellulose. Acrylic acid grafted starch materials are of this latter type. Thus, the preferred absorbent gelling materials include hydrolyzed acrylonitrile grafted starch, acrylic acid grafted starch, polyacrylates, maleic anhydride-based copolymers and combinations thereof. Especially preferred absorbent gelling materials are the polyacrylates and acrylic acid grafted starch.
Whatever the nature of the polymer components of the preferred absorbent gelling materials, such materials will in general be slightly cross-linked. Crosslinking serves to render these preferred hydrogel-forming absorbent materials substantially water-insoluble, and cross-linking also in part determines the gel volume and extractable polymer characteristics of the hydrogels formed therefrom. Suitable cross-linking agents are well known in the art and include, for example, (1) compounds having at least two polymerizable double bonds; (2) compounds having at least one polymerizable double bond and at least one functional group reactive with the acid-containing monomer material; (3) compounds having at least two functional groups reactive with the acid-containing monomer materials; and (4) polyvalent metal compounds which can from ionic cross-linkages. Cross-linking agents of the foregoing types are described in greater detail in Masuda et al; U.S. Pat. No. 4,076,663; Issued Feb. 28, 1978. Preferred cross-linking agents are the di- or polyesters of unsaturated mono-or polycarboxylic acids with polyols, the bisacrylamides and the di-or triallyl amines. Especially preferred cross-linking agents are N,Nxe2x80x2-methylenebisacrylamide, trimethylol propane triacrylate and triallyl amine. The cross-linking agent will generally comprise from about 0.001 mole percent to 5 mole percent of the preferred materials. More preferably, the cross-linking agent will comprise from about 0.01 mole percent to 3 mole percent of the gelling materials used herein.
The preferred, slightly cross-linked, hydrogel-forming absorbent gelling materials will generally be employed in their partially neutralized form. For purposes described herein, such materials are considered partially neutralized when at least 25 mole percent, and preferably at least 50 mole percent of monomers used to form the polymer are acid group-containing monomers which have been neutralized with a salt-forming cation. Suitable salt-forming cations include alkali metal, ammonium, substituted ammonium and amines. This percentage of the total monomers utilized which are neutralized acid group-containing monomers is referred to as the xe2x80x9cdegree of neutralizationxe2x80x9d. Typically, commercial absorbent gelling materials have a degree of neutralization somewhat less than 90%.
The preferred absorbent gelling materials used herein are those which have a relatively high capacity for imbibing fluids encountered in the absorbent articles; this capacity can be quantified by referencing the xe2x80x9cgel volumexe2x80x9d of said absorbent gelling materials. Gel volume can be defined in terms of the amount of synthetic urine absorbed by any given absorbent gelling agent buffer and is specified as grams of synthetic urine per gram of gelling agent.
Gel volume in synthetic urine (see Brandt, et al, below) can be determined by forming a suspension of about 0.1-0.2 parts of dried absorbent gelling material to be tested with about 20 parts of synthetic urine. This suspension is maintained at ambient temperature under gentle stirring for about 1 hour so that swelling equilibrium is attained. The gel volume (grams of synthetic urine per gram of absorbent gelling material) is then calculated from the weight fraction of the gelling agent in the suspension and the ratio of the liquid volume excluded from the formed hydrogel to the total volume of the suspension. The preferred absorbent gelling materials useful in this invention will have a gel volume of from about 20 to 70 grams, more preferably from about 30 to 60 grams, of synthetic urine per gram of absorbent gelling material.
Another feature of the most highly preferred absorbent gelling materials relates to the level of extractable polymer material present in said materials. Extractable polymer levels can be determined by contacting a sample of preferred absorbent gelling material with a synthetic urine solution for the substantial period of time (e.g., at least 16 hours) Which. is needed to reach extraction equilibrium, by then filtering the formed hydrogel from the supematant liquid, and finally by then determining the polymer content of the filtrate. The particular procedure used to determine extractable polymer content of the preferred absorbent gelling agent buffers herein is set forth in Brandt, Goldman and Inglin; U.S. Pat. No. 4,654,039; Issues Mar. 31, 1987, Reissue 32,649, The absorbent gelling materials which are especially useful in the absorbent articles herein are those which have an equilibrium extractables content in synthetic urine of no more than about 17%, preferably no more than about 10% by weight of the absorbent gelling material.
The absorbent gelling materials herein before described are typically used in the form of discrete particles. Such absorbent gelling materials can be of any desired shape, e.g., spherical or semi-spherical, cubic, rod-like polyhedral, etc. Shapes having a large greatest dimension/smallest dimension ratio, like needles and flakes, are also contemplated for use herein. Agglomerates of absorbent gelling material particles may also be used.
The size of the absorbent gelling material particles may vary over a wide range. For reason of industrial hygiene, average particle sizes smaller than about 30 microns are less. desirable. Particles having a smallest dimension larger than about 2mm may also cause a feeling of grittyness in the absorbent article, which is undesirable from a consumer aesthetics standpoint. Furthermore, rate of fluid absorption can be affected by particle size. Larger particles have very much reduced rates of absorption. Preferred for use herein are absorbent gelling material s particles substantially all of which have a particle size of from about 30 microns to about 2 mm. xe2x80x9cParticle Sizexe2x80x9d as used herein means the weighted average of the smallest dimension of the individual particles.
The amount of absorbent gelling material particles used in absorbent article will typically range from 10 gmxe2x88x922 to 150 gmxe2x88x922, preferably from 30 gmxe2x88x922 to 110 gmxe2x88x922, more preferably from 55 gmxe2x88x922 to 85 gmxe2x88x922.
Particularly suitable herein as an additional odor control agent is silica. Silica, i.e. silicon dioxide SiO2 exists in a variety of crystalline forms and amorphous modifications, any of which are suitable for use herein. In particular, silicas having a high surface area or in agglomerated form are preferred. Silica molecular sieves are not considered to be within the definition of silica as used herein. Preferably the silica is in a highly purified form such that. is contains at least 90%, preferably 95%, more preferably 99% silicon dioxide. Most preferably the silica is silica gel having a 100% silica content. Alternatively, the silica may be provided from other sources such as metal silicates including sodium silicate.
The use and manufacture of zeolite material is well know in the literature and is described in the following reference texts: ZEOLITE SYNTHESIS, ACS Symposium Series 398, Eds. M. L. Occelli and H. E Robson (1989) pages 2-7; ZEOLITE MOLECULAR SIEVES, Structure, Chemistry and Use, by D. W. Breck, John Wiley and Sons (1974) pages 245-250, 313-314 and 348-352; MODERN APPLICATIONS OF MOLECULAR SIEVE ZEOLITES, Ph.D. Dissertation of S. M. Kuznicki, U. of Utah (1980), available from University of Microfilms International, Ann Arbor, Mich., pages 2-8.
Zeolites are crystalline aluminosilicates of group IA and group IIA elements such as Na, K, Mn, Ca and are chemically represented by the empirical formula:
M2/nO . Al2O3. ySiO2. wH2O
where y is 2 or greater, n is the cation valence, and w is the water content in the voids of the zeolite.
Structurally, zeolites are complex, crystalline inorganic polymers based on an infinitely extending framework of AlO4 and SiO4 tetrahedra linked to each other by sharing of oxygen ions. This framework structure contains channels or interconnected voids that are occupied by the cations and water molecules.
The structural formula of a zeolite is based on the crystal unit cell, the smallest unit of structure, represented by
Mx/n[(AlO2)x(SiO2)y]. wH2O
where n is the valence of cation M, w is the number of water molecules per unit cell, x and y are the total number of tedrahedra per unit cell, y/x usually having values of 1-5.
Zeolites may be naturally derived or synthetically manufactured. The synthetic zeolites being preferred for use herein. Suitable zeolites for use herein include zeolite A, zeolite P, zeolite Y, zeolite X, zeolite DAY, zeolite ZSM-5, or mixtures thereof. Most preferred is zeolite A.
According to the present invention the zeolite is preferably hydrophobic. This is typically achieved by increasing the molar ratio of the SiO2 to AlO2 content such that the ratio of x to y is at least 1, preferably from 1 to 500, most preferably from 1 to 6.
The odor control agents (i.e., peroxyacid as described herein and optional additional odor control agent(s)) may be incorporated into the absorbent article by any of the methods disclosed in the art, for example layered on the core of the absorbent article or mixed within the fibres of the absorbent core.
The peroxyacid as described herein and optional additional odor control agent(s) are preferably incorporated between two layers of cellulose tissue. Optionally the system may be bonded between two cellulose tissue layers with, for example, a hot melt adhesive or any suitable bonding system, as described in WO 94/01069.
In one embodiment of the present invention the peroxyacid as described herein and optional additional odor control agent are incorporated in a layered structure in accordance with the disclosure of WO 94/01069 or Italian patent application number TO 93A 001028. TO 93A 001028 describes a layered structure substantially as described in WO 94/01069 with the exception that TO 93A 001028 comprises a much higher quantity of absorbent gelling material in the intermediate layer which is between the fibrous layers (120 gmxe2x88x922) that would be incorporated as an optional component in the present invention. The intermediate layer comprises in particular a polyethylene powder as thermoplastic material which is mixed with the peroxyacid as described herein. The mixture is then heated such that the polyethylene melts and glues the laminate layers together. Adhesive lines are preferably also placed on the edges of the laminate to ensure that the edges of the laminate stick and any loose peroxyacid as described herein and optional additional odor control agent present do not fall out of the laminate.
Alternatively, the polyethylene powder may be replaced by a conventional glue for instance those commercially available from ATO Findley under the name H20-31(copyright) to glue the laminate layers and/or components together. Advantageously this method step allows to avoid the heating step necessary when using polyethylene powder.
In a preferred embodiement the peroxyacid as described herein is incorporated between two layers of cellulose tissues separated by another layer of cellulose in order to avoid possible reaction between peroxyacid and the optional additional odor control agent.
The peroxyacid as described herein may be distributed homogeneously or non homogeneously over the entire absorbent article or in at least one layer of the topsheet or in at least one layer of the core or any mixture thereof. The peroxyacid as described herein may be distributed homogeneously or non homogeneously on the whole surface of the desired layer or layers, or on one or several area of the surface layer/layers to which it is positioned (e.g. central area and/or surrounding area like the edges of a layer of the absorbent article) or mixtures thereof. Preferably the peroxyacid is located towards the topsheet or is located in the topsheet itself (preferably the secondary topsheet).
In a preferred embodiment the peroxyacid is positioned such that at least a portion of the fluid discharge comes into contact with said peroxyacid before the additional odor control agent (e.g., AGM) if present. In particular, the peroxyacid is located in a separate layer from the additional odor control agent if present. Preferably the peroxyacid is located towards the topsheet or is located in the topsheet itself (preferably the secondary topsheet) and the odor control agent is located further away from the topsheet than the peroxyacid. In one embodiment of the present invention, the peroxyacid is positioned in at least one of the topsheet layers and the additional odor control agent is positioned in the core if present. More preferably, the peroxyacid is located at the fluid discharge entry point of the absorbent article.
The peroxyacid as described herein and optional odor control agent if present may be incorporated as a powder, a granulate or can be sprayed in the form of for example a peroxyacid-containing solution within the absorbent article. When used in a granulate or particulate form the peroxyacid as described herein and the optional odor control agent may be granulated separately and then mixed together or granulated together.
According to the present invention, the absorbent can include the following components: (a) an optional primary fluid distribution layer preferably together with a secondary optional fluid distribution layer; (b) a fluid storage layer; (c) an optional fibrous (xe2x80x9cdustingxe2x80x9d) layer underlying the storage layer; and (d) other optional components. According to the present invention the absorbent may have any thickness depending on the end use envisioned.
One optional component of the absorbent according to the present invention is a primary fluid distribution layer and a secondary fluid distribution layer. The primary distribution layer typically underlies the topsheet and is in fluid communication therewith. The topsheet transfers the acquired fluid to this primary distribution layer for ultimate distribution to the storage layer. This transfer of fluid through the primary distribution layer occurs not only in the thickness, but also along the length and width directions of the absorbent product. The also optional but preferred secondary distribution layer typically underlies the primary distribution layer and is in fluid communication therewith. The purpose of this secondary distribution layer is to readily acquire fluid from the primary distribution layer and transfer it rapidly to the underlying storage layer. This helps the fluid capacity of the underlying storage layer to be fully utilized. The fluid distribution layers can be comprised of any material typical for such distribution layers. In particular fibrous layers maintain the capillaries between fibers even when wet are useful as distribution layers.
Positioned in fluid communication with, and typically underlying the primary or secondary distribution layers, is a fluid storage layer. The fluid storage layer can comprise any usual absorbent material or combinations thereof. It preferably comprises absorbent gelling materials in combination with suitable carriers.
Suitable carriers include materials which are conventionally utilized in absorbent structures such as natural, modified or synthetic fibers, particularly modified or non-modified cellulose fibers, in the form of fluff and/or tissues. Suitable carriers can be used together with the absorbent gelling material, however, they can also be used alone or in combinations. Most preferred are tissue or tissue laminates in the context of sanitary napkins and panty liners.
An embodiment of the absorbent structure made according to the present invention may comprise multiple layers comprises a double layer tissue laminate formed by folding the tissue onto itself. These layers can be joined to each other for example by adhesive or by mechanical interlocking or by hydrogen bridge bands. Absorbent gelling material or other optional material can be comprised between the layers.
Modified cellulose fibers such as the stiffened cellulose fibers can also be used. Synthetic fibers can also be used and include those made of cellulose acetate, polyvinyl fluoride, polyvinylidene chloride, acrylics (such as Orlon), polyvinyl acetate, non-soluble polyvinyl alcohol, polyethylene, polypropylene, polyamides (such as nylon), polyesters, bicomponent fibers, tricomponent fibers, mixtures thereof and the like. Preferably, the fiber surfaces are hydrophilic or are treated to be hydrophilic. The storage layer can also include filler materials, such as Perlite, diatomaceous earth, Vermiculite, etc., to improve liquid retention.
If the absorbent gelling material is dispersed non-homogeneously in a carrier, the storage layer can nevertheless be locally homogenous, i.e. have a distribution gradient in one or several directions within the dimensions of the storage layer. Non-homogeneous distribution can also refer to laminates of carriers enclosing absorbent gelling materials partially or fully.
An optional component for inclusion in the absorbent core according to the present invention is a fibrous layer adjacent to, and typically underlying the storage layer. This underlying fibrous layer is typically referred to as a xe2x80x9cdustingxe2x80x9d layer since it provides a substrate on which to deposit absorbent gelling material in the storage layer during manufacture of the absorbent core. Indeed, in those instances where the absorbent gelling material is in the form of macro structures such as fibers, sheets or strips, this fibrous xe2x80x9cdustingxe2x80x9d layer need not be included. However, this xe2x80x9cdustingxe2x80x9d layer provides some additional fluid-handling capabilities such as rapid wicking of fluid along the length of the pad.
The absorbent core according to the present invention can include other optional components normally present in absorbent webs. For example, a reinforcing scrim can be positioned within the respective layers, or between the respective layers, of the absorbent core. Such reinforcing scrims should be of such configuration as to not form interfacial barriers to fluid transfer. Given the structural integrity that usually occurs as a result of thermal bonding, reinforcing scrims are usually not required for thermally bonded absorbent structures.
According to the present invention the absorbent article comprises as an essential component a topsheet. The topsheet may comprise a single layer or a multiplicity of layers. In a preferred embodiment the topsheet comprises a first layer which provides the user facing surface of the topsheet and a second layer between the first layer and the absorbent structure/core.
The topsheet as a whole and hence each layer individually needs to be compliant, soft feeling, and non-irritating to the wearer""s skin. It also can have elastic characteristics allowing it to be stretched in one or two directions. According to the present invention the topsheet may be formed from any of the materials available for this purpose and known in the art, such as woven and non woven fabrics and films. In a preferred embodiment of the present invention at least one of the layers, preferably the upper layer, of the topsheet comprises a hydrophobic, liquid permeable apertured polymeric film. Preferably, the upper layer is provided by a film material having apertures which are provided to facilitate liquid transport from the wearer facing surface towards the absorbent structure. If present the lower layer preferably comprises a non woven layer, an apertured formed film or an airlaid tissue.
The backsheet primarily prevents the extrudes absorbed and contained in the absorbent structure from wetting articles that contact the absorbent product such as underpants, pants, pyjamas and undergarments. The backsheet is preferably impervious to liquids (e.g. menses and/or urine) and is preferably manufactured from a thin plastic film, although other flexible liquid impervious materials can also be used. As used herein, the term xe2x80x9cflexiblexe2x80x9d refers to materials that are compliant and will readily conform to the general shape and contours of the human body. The backsheet also can have elastic characteristics allowing it to stretch in one or two directions.
The backsheet typically extends across the Whole of the absorbent structure and can extend into and form part of or all of the preferred sideflaps, side wrapping elements or wings.
The backsheet can comprise a woven or nonwoven material, polymeric films such as thermoplastic films of polyethylene or polypropylene, or composite materials such as a film-coated nonwoven material. Preferably, the backsheet is a polyethylene film typically having a thickness of from about 0.012 mm (0.5 mil) to about 0.051 mm (2.0 mil).
Exemplary polyethylene films are manufactured by Clopay Corporation of Cincinnati, Ohio, under the designation P18-0401 and by Ethyl Corporation, Visqueen Division, of Terre Haute, Ind., under the designation XP-39385. The backsheet is preferably embossed and/or matt finished to provide a more clothlike appearance. Further, the backsheet can permit vapors to escape from the absorbent structure, i.e. be breathable, while still preventing extrudates from passing through the backsheet. Also breathable backsheets comprising several layers, e.g. film plus non-woven structures, can be used.


Binoculars designed to provide a large aided static field of view are provided. The binoculars are characterized by S/D ratios of above 2.8, where S is the binoculars' aided static field of view calculated by multiplying the binoculars' magnifying power by the binoculars' semi field of view in object space and D is given by tan.sup.-1 [(R.sub.ex +1.5)/13], where R.sub.ex is the radius of the binoculars exit pupil the following expression in which R.sub.ex and the constants 1.5 and 13 are in milliliters. As a result of the increased S/D ratio, the binoculars of the invention minimize the sensation of tunnel vision which normally occurs when binoculars are used and reduce the user's apprehension of missing activities in his or her peripheral vision. In certain embodiments, a movable field lens unit is employed to provide variable power and a negative corrector lens unit is employed for aberration correction and to minimize the size of the binoculars. The binoculars are suitable for mass production and general consumer use.

1. Viewing Systems for Use with the .Human Eye
A variety of viewing systems for use with the human eye are known. They fall into two categories: 1) those which are normally fixed during viewing with respect to the object such as telescopes and microscopes ("fixed systems"), and 2) those which are normally moved during viewing with respect to the object such as eyeglasses, loupes, monoculars, and binoculars ("movable systems"). The present invention relates to movable systems and, in particular, to monoculars and binoculars. To simplify the presentation, the following discussion uses the term "binoculars." As so used, the term is intended to include both binoculars and monoculars.
To understand the benefits of the invention it is necessary to understand how a person observes an event without binoculars, i.e., unaided by a viewing system. The first step, in general, involves noticing the movement of the image of an object on the retina in the low resolution, peripheral vision. The extent over which such movement can be observed is the eye's "unaided static field of view". Next, the eye is moved (scanned) to follow or observe the object in greater detail, i.e., at high resolution, by aligning the eye's fovea with the object. The extent over which the eye can move to follow the object is the eye's "unaided dynamic field of view". Finally, the head is moved so that the eye is as straight ahead as possible with respect to the head.
For the purposes of the following discussion, these two fields of view of the eye, i.e., the eye's unaided static and dynamic fields of view, need to be distinguished from the eye's "aided static field of view" and "aided dynamic field of view" which are the fields of view achieved for a static and scanning eye, respectively, with binoculars held at a fixed position relative to the eye. These aided fields of view are defined and discussed in more detail below. As also discussed below, it should be noted that the eye's aided static field of view is the same as what is commonly referred to as a binoculars' "field of view" when transformed to image space.

Wide angle binocular system with variable power capability


Novel aqueous slurries capable of removing calculus, plaque or stains, adherent to tooth surfaces of a warm-blooded animal, when used in methods that are self-practicable by an individual human or practicable by an individual human on another warm-blooded animal, combine finely-divided charcoal; water; and alcohol, ammonia or hydrogen peroxide to form the slurries. Also disclosed are self-practicable methods that utilize the disclosed aqueous slurries by applying to, and contacting affected tooth surfaces with, the same, then removing the treated calculus, plaque or stains by means of devices and techniques that are safe to use according to the methods. Further, kits are disclosed that comprise the disclosed aqueous slurries, as well as apparatus, devices and tools for effectively using the same for the above purposes.

1. Field of the Invention
The present invention generally relates to compositions and methods useful for oral hygiene, and more particularly to such compositions and methods that are self-practicable by a human, or that can be practiced by a human on another human or other warm-blooded animal, for indicating the presence of and removing both plaque and calculus, as well as removing stains, adherent to tooth surfaces of the human or other warm-blooded animal.
2. Description of the Related Art
Practicing good oral hygiene is critical in the prevention of tooth decay and periodontal, or gum, disease. Periodontal disease is one of the most prevalent chronic diseases affecting humans and other mammals. Children as young as 5 years of age can have the disease. By the age of 35, three out of four people are affected, and by age 65, an estimated 98 percent of Americans have periodontal disease.
Before the onset of disease, healthy pink gingiva, or gum tissue, surrounds the teeth. Gum tissue, which is the soft tissue covering the neck of the tooth, serves to hold teeth in place and prevent infectious material from entering the jaw bone or tooth itself. The area between the tooth enamel and the gigiva is called the gingival crevice. Gums are constantly exposed to bacteria. Gingivitis typically develops when large masses of bacteria fill the gingival crevice, and is first manifested by bleeding gums. This inflammatory condition is reversible. Gum disease occurs when the gingival crevice between the tooth and gum is more than 3 mm deep.
As gingivitis progresses, the tissue surrounding the teeth is destroyed and the supporting collagen fibers degenerate, leaving abnormally deep (1 to 3 mm) crevices, or pockets adjacent to the teeth due to the loss of gum attachment thereto. As the pockets grow, and the amount of bacteria therewithin increases, the gums recede down the root of the teeth. Eventually, the bone supporting each affected tooth socket degenerates and results in tooth loss. These are the defining characteristics of periodontal disease. In fact, the latter is the principal reason that adults have teeth removed. Typically, this is a slow, painless, progressive disease and, hence, is insidious in nature.
More specifically, periodontal disease is caused by certain types of bacteria that form a clear (almost invisible), sticky, film of the bacteria, having an organized structure and referred to as dental plaque (hereinafter, xe2x80x9cplaquexe2x80x9d). Plaque is not food or food residue. Plaque forms at all ages and on both non-permanent (xe2x80x9cbabyxe2x80x9d) and permanent (adult) teeth. It adheres to the surfaces of teeth, gum tissues, dental restorations, and even the tongue and is adherent to the point that it cannot be washed or rinsed off. Instead, plaque must be removed mechanically. Brushing and flossing are most commonly used. Picking and scraping may also be used. Such techniques are effective in removing the plaque that is, in fact, accessed thereby.
Studies have shown that plaque forms very soon after it is removedxe2x80x94from as soon as five minutes, to up to four hours after removal. It is fair to say that plaque must be continually removed and that its formation cannot be stopped. When all oral hygiene measures are suspended, gingivitis can result from the presence of plaque within about three weeks. As noted, gingivitis is reversible. With diligent flossing and toothbrushing, the inflammatory condition usually disappears. In the absence of such measures, periodontal disease is sure to follow. Plaque also causes tooth decay (cavities).
Despite normal diligence in removal of plaque, which may be regarded as thoroughly brushing teeth twice a day, and proper flossing between all teeth daily, some amount of plaque remains. Thus, the formation of calculus (also referred to as tartar), which stems from the presence of plaque, appears to be inevitable. In fact, research has shown that about 92% of Americans have a significant accumulation of calculus in their mouths. Calculus forms when the calcium carbonate and phosphate in saliva combine with plaque at the tooth surface and precipitates to form a hard and tough, unsightly scale deposit not unlike a limestone type substance. Once the deposit mineralizes, it can grow rather quickly. Typically, calculus is yellow or brown in color. It bonds cohesively with teeth and, unlike plaque, cannot be removed by normal brushing or flossing.
Calculus can exist both above the gum line as a hard deposit on the top portion of teeth (supragingival calculus), and below the upper gum surface (subgingival calculus). Supragingival and subgingival calculus deposits are equally hard and adherent. The surface of calculus tends to be rough and filled with microscopic holes. In fact, when examined under a microscope, it is apparent that calculus has a myriad of nooks and crannies, not unlike a coral reef.
The removal of calculus is an important aspect of good dental hygiene for a number of reasons. First, as noted above, it is unsightly due to its yellow or brown color. Also, it absorbs stains easily. Therefore, its removal is important from an aesthetic standpoint. Second, the microscopic holes found therein harbor food particles, bacteria, and viruses that cause swelling and bleeding of the gums. Third, the rough surface of calculus both attracts bacterial plaque to tooth surfaces, and enhances its adherence thereto, making thorough plaque removal more difficult. When this layer of plaque mineralizes, more calculus forms, and the result is a continuous cycle of accumulation. This cycle is particularly problematic in the case of subgingival calculus and is a significant contributor to more extreme conditions of gingivitis and periodontal disease. In the case of supragingival calculus, this cycle is also problematic, principally as a contributor to tooth decay.
As noted, hard calculus cannot be removed by normal brushing and flossing. Typically, it is mechanically removed by dentists and dental hygienists by scraping, picking, drilling and abrading with metal instruments having hard, sharp edges and tips. Often, the movement of the instruments is by manual manipulation, although, for example, an oscillating device, typically having a metal tip and operating at ultrasonic frequencies, may be used. Such removal of calculus is most often performed on a patient on a rather infrequent basis. Twice a year is usually recommended. Often, patients will avail themselves of such calculus removal only once a year, or less frequently.
One of the principal disadvantages of this approach to calculus removal is associated with the infrequency of the removal. The extended period of time between visits to the dentist is likely to allow significant accumulation of calculus and plaque, and, thus, the tooth decay and gingivitis that is often associated therewith. A resultant, additional disadvantage is the pain and discomfort associated with the calculus removal (especially when gingivitis is extant) and the repair of damage often caused by the accumulation of calculus and plaque (e.g., drilling to remove decayed tooth matter and filling the tooth to replace the same. Other resultant disadvantages include the considerable expense and inconvenience associated with the above.
If the individual patient could self-practice the above techniques, used by dentists and dental hygienists, for calculus removal, as part of a frequent and regular, personal oral hygiene regimen, some of the above disadvantages could be avoided. However, such use of the methods and instruments, typically used by the skilled dental practitioner on a patient, would be hazardous and likely to result in serious injury to teeth, gingiva, and other soft tissues in the mouth. Accordingly, various methods, devices and compositions, other than those associated with conventional tooth brushing and flossing, have been described as allegedly suitable for use by a patient to remove at least some calculus as part of personal oral hygiene, while avoiding the risk of such injury.
For example, U.S. Pat. No. 4,878,508 describes a device that can be used for personal oral hygiene for removal of plaque and tartar. The device is essentially an arcuate pick having a pointed lead end and a more wide, truncated end. The pick is made of a resilient material, has two sides that are joined to form a V-shaped cross-section, and includes cilia, spaced ridges, and bristles along the sides. Also, the edges of the two sides are beaded to avoid cutting gingival tissue. U.S. Pat. No. 5,711,935 describes bundled, multi-fiber dental floss that is loaded with agents, including abrasives and anti-tartar agents, and that presumably could have some utility in removal of calculus.
A hand-held device having an oscillating (at a frequency of at least 5 Khz) head with a wooden toothpick releasably attached thereto, is described by U.S. Pat. No. 5,393,229. The device is described as suitable for use by dental professionals to clean a patient""s teeth, or by an individual for personal use, by virtue of using a wooden toothpick, rather than a metal tip. The device is further described as able to hold a toothpick in either a perpendicular or coaxial orientation with respect to its head for cleaning between teeth and between teeth and gingiva. Also disclosed, is coating the toothpick with various reagents, including an anti-calculus agent such as citric acid or pyrophosphate. However, there is no assertion made therein that the device provides an effective means for calculus removal.
U.S. Pat. No. 4,270,556 describes a device allegedly useful for removal of plaque, calculus and stains from interproximal tooth surfaces without abrading or damaging tooth enamel. The device is essentially a very thin stainless steel strap that is perforated, the perforations having raised peripheral edges useful for scaling or scraping. Also, the stainless steel used is disclosed as softer than tooth enamel so as not to damage the same. The device is used in much the same manner as dental floss.
U.S. Pat. No. 5,875,798 mentions that toothpicks have a number of utilities, including: removing food particles, stimulating gum tissue, and removing both plaque and calculus. Also mentioned is the existence of dental floss that contains, among other agents, anti-tartar agents such as tetrasodium pyrophosphate, sodium acid pyrophosphate and tetra potassium pyrophosphate. Disclosed as novel therein is a toothpick that includes a saliva-soluble coating near an end thereof, where the coating comprises anti-tartar agents.
A toothpick, described as novel and allegedly capable of removing calculus, is also disclosed in U.S. Pat. No. 3,954,115. The disclosed toothpick is resilient, being made from a synthetic resin, and includes a chisel-shaped end and roughened or knurled sides, adapted for scraping and abrading tooth surfaces, respectively, when the toothpick contacts the same in a reciprocating fashion. U.S. Pat. No. 4,271,854 describes a pliable toothpick, made from injection moldable material, and having a rigid middle portion and tapered, arcuate end portions. At least some of the end portion surface is roughened and, thereby, abrasive. The toothpick is described as capable of removing early stages of tartar scale from interproximal and proximal tooth surfaces by means of contacting the same with the roughened surface of an end portion in a reciprocating fashion.
Also described, in addition to the above-discussed devices and related methods, as allegedly suitable and effective for removing at least some calculus as part of a personal oral hygiene regimen, are various compositions that can be used with otherwise conventional brushing methods. For example, German Patent No. DE 2637862 describes a powdered tooth care composition comprising 10-95% charcoal, 5-25% walnut bark, and 1-15% NaCl that is allegedly capable of removing both plaque and calculus. Also, Japanese Patent No. 2000128751 describes a toothpaste that is 0.05 to 5%, by weight, hard charcoal powder and that is to be applied by ordinary tooth brushing. Assertedly, the described toothpaste allows for the removal of already deposited dental calculus.
As the above-described devices and compositions, and methods related thereto, have limited effectivity with regard to the removal of both subgingival and supragingival calculus and/or present excessive risk of injury to teeth, gingiva or other soft tissues in the mouth when self-practiced, there remains a need in the art for devices and/or compositions, and methods related thereto, that can, when self-practiced, be used safely, easily and effectively to remove calculus from teeth, in addition to plaque and stains. The benefit of such devices and/or compositions, and methods related thereto, with regard to calculus removal should at least suffice to effectively supplement the benefit of less frequent calculus removal performed by dental professionals. The present invention fulfills these needs and provides further related advantages.
In brief, the present invention is directed to aqueous slurries useful for removing both plaque and calculus, as well as stains, from affected tooth surfaces when applied directly thereto so as to contact the calculus, plaque or stains to be removed, and combined with mechanical removal of the same. The present invention, in another aspect, is also directed to methods, self-practicable by individual humans (xe2x80x9cindividualsxe2x80x9d or xe2x80x9cpatientsxe2x80x9d) in need thereof or practicable by individuals on patients or other warm-blooded animals, for removing both plaque and calculus, as well as stains, from tooth surfaces that use the above slurries in combination with mechanical application of the same, as well as mechanical removal of the calculus and/or plaque and/or stains contacted with the slurries.
In yet another aspect, the present invention is directed to kits, useful for such removal, that include the above slurries or the components (i.e., charcoal and liquid portion) thereof, as well as a means for measuring and mixing the components, a means for effectively applying the slurries to affected tooth surfaces, and a means for removing the treated calculus, plaque or stains.
More specifically, in one embodiment, the present invention is directed to slurries, useful for removing calculus, plaque or stains adherent or otherwise attached to tooth surfaces, wherein the slurries are formed by combining finely-divided charcoal and a liquid portion so as to create a slurry therefrom, the liquid portion comprising water, as well as alcohol, ammonia or hydrogen peroxide. Such slurries have been found to be surprisingly effective in removing both plaque and calculus adherent to tooth surfaces, even when self-administered by an individual in need thereof.
In another embodiment, the present invention is directed to a method for removing calculus, plaque or stains adherent to tooth surfaces, the method being self-practicable by an individual in need thereof or practicable by an individual on another individual or another warm-blooded animal and using the above slurries. The method, as applied, for example, to the removal of calculus, comprises: coating affected tooth surfaces with an effective amount of any of the above slurries; then contacting, for an effective period of time, the calculus to be removed and now having the aqueous slurry coated thereupon; optionally, repeating the above steps as necessary or desired; then, mechanically removing the contacted calculus from the affected tooth surfaces; optionally, repeating the above steps until a desired extent of removal of the calculus from the affected tooth surfaces and oral cavity is accomplished; and, finally, mechanically and/or rinsingly removing any residual slurry and loosened calculus from the affected tooth surfaces and other tooth surfaces, as well as from other surfaces of the oral cavity. Basically, the same method can be used to remove plaque from affected tooth surfaces.
The coating step (i.e., first step), optionally combined with the contacting step (i.e., second step) of the above method, also provides a method for visually indicating the presence of calculus or plaque adherent to tooth surfaces. The method for such indicating is another aspect of the present invention.
In yet another embodiment, disclosed is a kit adapted for removing calculus, plaque or stains adherent to tooth surfaces in the oral cavity of an individual in need thereof. The kit is intended for use by the individual, with or without the assistance of another. The kit includes a quantity of any of the above aqueous slurries, or quantities of components thereof, namely, a quantity of finely-divided charcoal and quantities of the constituents of a liquid portion or a quantity of the liquid portion. The kit further includes, where the kit contains the components of the aqueous slurry to be used, a container and device adapted to mix quantities of the components in a desired ratio; an applicator for coating affected tooth surfaces with the slurry; a device adapted to cause, by mechanical action, the applied slurry to agitatively and frictionally contact the tooth surfaces and adherent plaque and calculus coated thereby and, further, to coat and contact, as described above, tooth surfaces not coated with the slurry by means of the applicator; a device adapted to mechanically remove the plaque and calculus, thus contacted, from the affected tooth surfaces; and, optionally, a device and/or rinsing agent adapted to mechanically or rinsingly remove any residual portion of the slurry, as well as any loosened plaque or calculus not already removed, from the affected tooth surfaces and other tooth surfaces, as well as the other surfaces of the oral cavity.
These and other aspects of the present invention will be evident upon reference to the following detailed description of the invention.
As mentioned above, the present invention is directed to aqueous slurries useful, when applied by an individual human (hereinafter, xe2x80x9cindividualxe2x80x9d or xe2x80x9cpatientxe2x80x9d) for personal oral hygiene or when applied to another warm-blooded animal, including an individual (hereinafter, xe2x80x9csubjectxe2x80x9d), for indicating the presence of, and removing, both plaque and calculus, particularly calculus, as well as for removing stains, from affected tooth surfaces, and to related methods and kits. The terms xe2x80x9cteethxe2x80x9d and xe2x80x9ctooth,xe2x80x9d as used herein, refer to the teeth of warm-blooded animals, including a human. The expressions xe2x80x9ccalculus or plaque,xe2x80x9d as used herein, means calculus and/or plaque. Further, the expression xe2x80x9ccalculus, plaque or stains,xe2x80x9d as used herein, means calculus and/or plaque and/or stains.
In one embodiment, disclosed is such an aqueous slurry formed by combining and mixing finely-divided charcoal and a liquid portion, where the liquid portion, in related embodiments, comprises water combined with alcohol, ammonia or hydrogen peroxide. As used herein, the expression xe2x80x9cfinely-divided charcoalxe2x80x9d also refers to powdered charcoal, finely-divided or powdered carbon, or activated charcoalxe2x80x94all of which are hereinafter referred to by the term xe2x80x9ccharcoal.xe2x80x9d As is known to those skilled in the art, charcoal is typically black in color and derived from carbonaceous materials such as wood, peat and coconut shells to yield an odorless, tasteless form of carbon that is safe for consumption by humans and other mammals. Uses include neutralizing drugs and poisons; providing intestinal gas relief; preventing intestinal infections; purifying air, water, foodstuffs, chemicals and pharmaceuticals; and cleaning surfaces, including tooth surfaces.
Charcoal products are readily commercially available. Some examples of products that are particularly suitable for the present invention are the charcoal products manufactured and sold by Norit Americas Inc. (Atlanta, Ga.) and designated as Norit(copyright)A Supra, Norit(copyright)B Supra, and Norit(copyright)E Supra. The laster products comprise carbon particles, 97% (by weight) of which are less than 150 microns in diameter. Various sizes of carbon particles can be used. Generally desirable, are particle sizes that allow the carbon particles to become suspended in the liquid used for the composition, and that allow the carbon particles to be mechanically or fluidly transported to and away from interproximal tooth surfaces and tooth surfaces in the gingival crevice, in addition to proximal tooth surfaces.
In a particular related embodiment, the liquid portion comprises water and alcohol as miscible mixture thereof. Such mixtures, such as rubbing alcohol, are either readily commercially available, or readily prepared from water and various alcohols. A few examples of alcohols that can be used are methanol, ethanol and propanol (including isopropyl alcohol. Various concentrations of alcohol in water are suitable. In a related embodiment, the concentration of the alcohol in the water ranges from about 25% to about 70%, by volume.
In a further, more particular related embodiment, the alcohol is provided by ordinary, commercially available mouthwash, such as Listerine(copyright) (Warner-Lambert Consumer Healthcare, Morris Plains, N.J.), Scopeo(copyright) (Proctorand Gamble, Cincinnati, Ohio) and Plax(copyright) (Pfizer, Inc., New York, N.Y.), to name a few. As used herein, the term xe2x80x9cmouthwashxe2x80x9d is synonomous with the term xe2x80x9cmouthrinse.xe2x80x9d The mouthwash is simply combined and mixed with a quantity of charcoal to form a slurry. Various relative amounts of mouthwash and charcoal may be used. Also, the mouthwash may be used in preparing the slurry when in a concentrated form, as purchased off the shelf, or after being diluted with water.
As noted, disclosed in one embodiment is an aqueous slurry formed by slurrying charcoal in a liquid portion that comprises water and ammonia. More particularly, the liquid portion is a solution of ammonia in water. Such solutions are readily commercially available and prepared by methods well known to those skilled in the art.
Also as noted, in another embodiment of the present invention, disclosed is an aqueous slurry comprising charcoal slurried in a liquid portion that comprises water and hydrogen peroxide. Aqueous solutions of hydrogen peroxide are prepared by methods well known in the art and are used for bleaching, oxidizing, deodorizing, and disinfecting. When the concentration of the hydrogen peroxide in the aqueous solution is at least about 3% by weight, the solution is used medicinally as a disinfectant, for example, to cleanse wounds. Such solutions are readily commercially available.
It has been surprisingly and unexpectedly found that, when the disclosed slurries are used as described below, they are effective to indicate the presence of plaque and calculus and to remove the same from tooth surfaces to an extent greater than that achievable with charcoal alone (i.e., charcoal and saliva) or with charcoal and water when used in a similar fashion. While not wishing to be bound by any theory, Applicant believes that the above finding stems from the ability of the aqueous slurries disclosed herein to at least partially dissolve and, thus, soften, calculus when applied thereto and intimately contacted therewith, as described below.
Again, not wishing to be bound by any theory, it is also believed that such dissolution and softening allows the black charcoal in the disclosed slurries to mix with and adhere to the calculus, thus, accounting for the ability of the slurries to serve as an indicator of the presence of calculus adhering to tooth surfaces. Such indication of its presence, as well as the at least partial dissolution and softening thereof by the slurries, expedite the removal of adherent calculus by the methods discussed below, such methods heretofore having been effective only in removing plaque.
Other surprising and unexpected advantages are associated with the use of the disclosed aqueous slurries. Specifically, the disclosed slurries provide the unexpected results described above, while further providing the unexpected benefits of less irritation during use to gingival tissue, generally less pain during use, and less abrasion of tooth enamel, as compared to using charcoal only, charcoal and water, or other methods. More particularly, the disclosed slurry that comprises charcoal slurried in water and ammonia surprisingly exhibits nerve-deadening properties. Another benefit of the disclosed slurries is their allowing for the removal of calculus, plaque and stains from tooth surfaces in a more antiseptic environment.
In another aspect, the present invention is directed to a method for removing calculus, plaque and stains from the teeth of an individual or subject, where the method is self-practicable by an individual or practicable by an individual on a subject. The first step of the method is applying an effective quantity of a disclosed aqueous slurry to affected tooth surfaces so as to coat the calculus, plaque or stain adherent thereto. As would be appreciated by one skilled in the art, any one of a variety of means for so applying the slurry may be used. In one related embodiment, tooth and gingival surfaces, and other surfaces in the oral cavity, are so coated by taking an effective quantity of the slurry into the oral cavity and swishing the slurry therearound so as to coat the various surfaces therein.
In another related embodiment, an application means is used to apply disclosed aqueous slurries to affected tooth surfaces. Various application means can be used and include, as some examples, fingertips, floss, a toothbrush, a cotton-tipped toothpick, or a cotton swab. A toothbrush and a cotton swab are, for example, particularly suitable for applying the compositions to proximal tooth surfaces, while a cotton-tipped pick and floss are, for example, more suitable for applying the slurries to affected tooth surfaces that are interproximal or subgingival. The picks and swabs need not be tipped with cotton. Any absorbent material capable of efficiently transporting the disclosed slurries to affected tooth surfaces without damaging the latter, or other surfaces in the oral cavity, may be used.
The second step of the disclosed method is contacting, for an effective period of time, the affected tooth surface with the aqueous slurry applied thereto. In a related embodiment, the contacting step comprises agitative and frictional contact between the affected tooth surface and the slurry applied thereto. Generally, to accomplish such contact, the surface of a device is directly rubbed against or upon the calculus, plaque or stains adherent to the affected tooth surface while a quantity of the slurry is resident between the device and tooth surfaces. Surprisingly, effective removal of calculus, plaque and stains is accomplished even with gently rubbing.
Devices should be used that can be rubbed against the tooth and gingival surfaces without causing damage or injury thereto. Brushes and swabs tipped with cotton or another soft, absorbent material are particularly suitable for this purpose. Also, they can be used to hold and apply additional quantities of the slurries during the rubbing step. Fingertips may also be used.
For interproximal and subgingival areas of tooth surface, floss can be used, as can any of various types of picks such as those described previously. For example, resilient picks made from wood, including bamboo, or resinous material may be used. The picks may or may not have a roughened surface or a surface comprising raised portions adapted for scraping or abrading. Picks that taper, at least on one end, to a fine point, are particularly useful for interproximal and subgingival areas. Different motions can effect the agitative and frictional contact between the device and tooth surface, and may be characterized as a back and forth, or reciprocating motion, a circular motion, or a scraping motion.
The aqueous slurry may be so applied to and contacted with affected tooth surfaces, optionally, in a repeated alternating fashion for an effective period of time. Such a period of time would at least be of sufficient duration to allow for the indication by staining, as well as the at least partial dissolution, or softening, of calculus adherent to tooth surfaces. This is manifested by the appearance of a black material having a surface characterized by a viscous, sticky appearance. Typically, the material comprises plaque and at least a portion of the calculus that has been softened to the point that it can be mechanically removed by methods described below.
The aforementioned removal is the third step of the disclosed method and is accomplished using essentially the same devices used with the aqueous slurries to create the softened calculus. Accordingly, the material is removed from tooth surfaces and from the oral cavity, for example, on the surface of floss, a brush, a swab or a pick, having been transferred to the surface by scraping, brushing, or rubbing the device or devices against the tooth surface having the material thereon. Then, either the material is transferred from the device for disposal and the device reused, or the device with material thereon is discarded and a new, clean device is then used for additional material removal. Also, additional slurry, or liquid, used for the preparation thereof, or charcoal can be applied to the device to expedite removal of the softened calculus and/or plaque. Some other liquid cleaner or toothpaste could also be used. A vacuum device could also be used for material removal, alone or in combination with the above-described devices.
Characteristically, calculus deposits are removed, as described above in a gradual, layer-by-layer fashion. Accordingly, the above steps are typically repeated until all or a desired degree of the calculus, plaque or stain is removed.
The final step of the disclosed method is removing residual amounts of slurry remaining in the oral cavity, as well as any loose portions comprising calculus or plaque. As one example, this may be accomplished by conventional brushing of tooth and other surfaces in the oral cavity with toothpaste, followed by rinsing with water.
It may be appreciated that the aqueous slurries used for the above-disclosed method may be prepared by combining and mixing the charcoal and liquid portion prior to applying the slurry to the affected tooth surfaces, or may be combined and mixed in situ, that is, in the oral cavity. For example, in the latter case, the liquid portion is first applied to tooth surfaces by introducing a bulk quantity thereof into the oral cavity and swishing it about therein and thereafter expelling any excess amount, or by using an applicator as described above. Then, the charcoal can be applied to the tooth surfaces using, for example, the same devices and methods described above for rubbing the surfaces with the slurry. The charcoal and liquid portion are then mixed to yield the slurry during the course of rubbing the tooth surfaces.
In another aspect, the present invention is directed to a method for indicating the presence of calculus or plaque adherent or attached to tooth surfaces. The disclosed method entails coating affected tooth surfaces with an aqueous slurry of the present invention. Optionally, as needed, the tooth surfaces are then contacted with the slurry for a period of time until the calculus and/or plaque, so coated and contacted, has imparted thereto a visible black color. The coating and contacting steps may be carried out in essentially the same manner as the corresponding steps in the above-disclosed method for removal of calculus and plaque and stains from tooth surfaces. Optionally, as needed, the coating and contacting steps may be repeated until a sufficiently visible black color is imparted to the calculus or plaque. In a related embodiment, charcoal alone, or a charcoal and water mixture is used, essentially as described above, in a method for indicating the presence of plaque.
A related embodiment discloses a method for selectively indicating the presence of calculus, adherent to tooth surfaces. The method is carried out using the same steps as the method for indicating the presence of calculus and plaque, except that, prior to using the same steps, all tooth surfaces are first thoroughly brushed with toothpaste and flossed to remove most or substantially all of any plaque thereon.
In another aspect, the present invention is directed to a kit adapted for removing calculus, plaque or stains adherent to or otherwise attached to tooth surfaces in the oral cavity of an individual or subject. The kit provides components used in methods for such removal that are either self-practicable by an individual or practicable by an individual on a subject. The kit comprises: 1) a quantity of a disclosed aqueous slurry in a sealed container, or quantities of charcoal and a liquid portion (or constituents thereof, e.g., water and alcohol, ammonia or hydrogen peroxide) in separate sealed containers; 2) a mixing device, such as one or more stirrers, to mix the charcoal and liquid portion so as to form a slurry of the same; 3) where the charcoal and liquid portion (or constituents thereof) are provided in separate sealed containers, an additional, empty container adapted to provide a reservoir for combining measured quantities of the charcoal and liquid portion (or constituents thereof) in desired ratios; 4) one or more devices for applying the composition to affected tooth surfaces; 5) one or more devices for agitatively and frictionally (e.g., rubbing) contacting the tooth surfaces with the composition; 6) one or more devices for mechanically removing contacted calculus or plaque from the tooth surfaces; and 7) optionally, a device and/or rinsing agent for mechanically or rinsingly removing residual portions of the composition, as well as loose portions of calculus or plaque from the tooth and other surfaces of the oral cavity.
The above-mentioned devices included in the kit are as described in the previously-described methods of the present invention. In a related embodiment, disclosed is a kit wherein the devices included therein for use in the slurry application and contacting steps comprise a surface that is impregnated with charcoal.
The following example is provided for purposes of illustration, not limitation.

Aqueous slurries useful for cleaning teeth and methods related thereto