A BRUSH-APPLIABLE DENTIFRICE

Abstract: The invention relates to a brush-applied dentifrice which conveniently contains an abrasive, a thickener, a colourant, a surface tension reducing agent and/or a preservative among other things, and in which 5-20 % of the dentifrice is comprised of a tooth-surface polishing and abrasion-reducing substance, such as silicone oil.

Description: TITLE OF THE INVENTION. A Brush-appliable Dentifrice. TECHNICAL FIELD. The present invention refers to a brush-appliable denti¬ frice which may advantageously have a paste-like consis¬ tency and which has been developed particularly for cleaning teeth with the aid of a toothbrush. BACKGROUND ART Several different types of toothpastes having individual compositions and intended for cleaning the teeth, pre¬ paring the surfaces of the teeth to avoid caries infec¬ tion and to counteract gum inflammation are known to the art. Commercially available toothpastes intended for one or more of the aforesaid purposes contain: an abrasive, a thickener, colourants, a surface tension reducing agent, preserving agents, etc. Comprehensive investigations, clinical tests and devel¬ opments have been and carried out over many years in an attempt to improve the cleaning and- anti-caries effect of toothpastes, in addition to their reducing effect and gum inflammation counteracting effect. Particular weight has been placed on the abrasive effect of toothpaste. Parallel wιτ_n.these investigations and tests, attempts have been made to find ways in which the polishing effect of toothpaste can be enhanced without needing to abrade the tooth enamel to any significant extent. Those methods applied hitherto to this end have included endeavours to change the composition of the toothpaste and therewith achieve the desired effect from the abra¬ sive used in different ways. hen considering the singularities associated with the present invention, it should be noted that although the pellicle layer on the tooth enamel and on the dentine surfaces (necks of the teeth) is quickly broken down and brushed away when the toothpaste or dentifrice used includes a coarse abrasive, such a toothpaste can result in abrasive damage to the teeth, primarily on the den¬ tine surfaces. On the other hand, a toothpaste which contains a fine abrasive requires longer time and more intensive brush¬ ing in order to clean away the pellicle layer and is therewith also gentler on the dentine surfaces. The pellicle layer is a layer or film that forms over the surfaces of the teeth immediately after the teeth have been cleaned. Bacteria and discoiourations, caused by tobacco, tea and wine for instance, adapt to this layer. When considering the singularities associated with the present invention, it should be mentioned that it has been proposed to cover the entire surface of a clean tooth from which the pellicle layer has been removed with a pure siiicone oil. This proposal has also been testeα . It has been found that a pellicle layer which forms on an underlying layer of 100% siiicone oil is different than is otherwise the case and has more favourable properties, which enable the pellicle layer to be re¬ moved more easily, among other things. It can also be expected that a pellicle layer which forms on an underlying siiicone oil film will have less tendency to function as a bacteria culture medium or nutrient. Furthermore, it can also be expected that a 100%-siii- cone oil will adhere firmly to the clean surface of a tooth. It is known to coat the surfaces of teeth with a thin film of pure siiicone oil from an article "Effect of siiicone oil on protein adsorption to hydroxyapatite in vitro and on pellicle formation in vivo" by Marten Rykke and Gunnar Roila. "Scand. J. Dent. Res. 1990, 98. 401-II" . It should also be mentioned that it is known to add a very small amount of siiicone oil (about 0.2%) to a dentifrice, such as toothpaste, for the aforesaid rea¬ son. It has been suggested in the GB Patent Publication 686 429, as a new and noval dentifrice containing organopolysiloxan Here it is suggested an improved dentifrice with aids in preventing the adhersion of or facilitates the removal of tars, stains, tartar and food particles. It has here been found that the above objects can be accom¬ plished by incorporating an organopolysiloxane in a dentifri¬ ce of the liquid, paste, or powdered type; and by brushing the teeth with such a dentifrice. Thus, a this film of the organopolysiloxane is deposited on the teeth, rendering them relatively non-adherent to foreign materials. The composition mentioned comprises from 0,5 to 45 per cent, by weight of an organopolysiloxane, from 0,5 to 99,0 per cent, by weight of a dentifrice abrasive, from 0,5 to 10 per cent, by weight of a non-toxic detergent, from 0 to 50 per cent, by weight of a non-toxic inert diluent, from 0 to 20 per cent, of a non-toxic emulsifying agent, and from 0 to 98,5 per cent, by weight of water. The proportions of these ingredients used depends upon whether a liquid, paste, or powdered dentifrice is desired. The organopolysiloxanes used are those having an average of from 1 to 3 hydrocarbon radicals per siiicone atom as alkyl, such as methyl, ethyl, butyl, and octadecyl; aryl such as phenyl, tolyl, clorophenyl and xenyl; or aralkyl such as benzyl. These polysiloxanes may vary from low viscosity liquids to solids. The liquid types of polysiloxane are particularly preferred, however. The organopolysiloxanes are well-known, commercially available materials. The abrasives used are those commonly used in dentifrices. The only critical requirements of such abrasives are those of non-toxicity and the ability to polish without injury to tooth enamel. Such abrasives are well-known commercially and include materials such as; Ca 2 P 2 0 6 .2H 2 0, Ca 2 P 2 0 6 , MgC0 2 , CaC0 2 , Ti0 2 , talc, and bone ash. The detergents used in accordance with the present invention may be any of those commercially used in toothpastes. A wide choice of such detergents is available. The only critical features are that they be non-toxic and have wetting, scou- ring, or surface-active properities. Thus many various fatty and derivatives and soaps may be used. Particularly preferre are the sodium salt of lauryl sulphate (marketed as "Dreft" by the Procter and Gamble Distributing Co. ) and glyceryl sulpho-acetate (marketed as "Nacconal Lai" by the National Analine Division of the Allied Chemical and Dye Corporation). Castile soap is also highly effective. Non-toxic inert diluents such as glycerine, polyethylenegly- cerol, propylene glycol, butyl stearate, and the like may be used if dessired to act as extenders for the organopolysilox ane. Non-toxic dispersing or emulsifying agents may also be used, but are not particularly necessary for a formulation of satisfactory properties. It has also been suggested, in the GB Patent Publication 1 194 885 a noval dentifrice containing siiicone oils, which will preferentially coat teeth with silcone film which can not be readily displaced by moisture, thereby eliminating or greatly reducing the problem of dental decay. Various attempts have been made to solve the problem of dental decay but the problem still exists Fluoridization of drinking water and regular and frequent use of certain prophylactic dentifrices containing active fluorides have been shown to reduce somewhat dental decay incidence in children but such measures are not effective for older per¬ sons whose teeth have already formed. The addition of siiicone oils with and without an organic titanate to dentifrice compositions has been proposed but experience has shown that these inert siiicone oils do form durable or continuous coatings on teeth because the moisture on the teeth and in the dentifrice interferes with the depo- sit of the siiicone film on the teeth, This is believed to b d ue to the fact that there is a stronger attraction between t h e polar surface of teeth and water, which is polar, than between the teeth and less polar siiicone oils which causes at least partial displacement of siiicone film by water. Much work has been published on siiicone compositions that will deposit durable siiicone films on polar substances such as glass. These compositions generally employ reactive sili- cones such as alkyl alkoxy silanes and particularly effectiv are reactiave silicones with an organic ester of titanium. However, these compositions must be stored under anhydrous conditions or they polymerize and become useless. Since most dentifrices contain water, these reactive silicones cannot b used in dentifrices. Dentifrice compositions thus described comprise a dimethyl polysiloxane and a quaternised tertiary cyclic amine in whic a C 8 . 22 aliphatic radical is attached to the quaternary nitro¬ gen atom. The composition may also contain an organic solvent to promote the solubility of the quaternised amine in the dimethylpolysiloxane. The compositions are used for the prevention of cavity formation in teeth and the siloxane and the specified additive serve as protective agents. The compo¬ sition may contain, in addition to the siloxane and the quaternised amine, other ingredients such as those conventio¬ nally used in dentifrice compositions. This composition claims to preferentially coat the teeth with a siiicone film which adheres tenaciously to teeth even in the presence of water and saliva and have the advantage that it is not necessary to isolate and dry the teeth to be trea¬ ted. Another advantage of the compositions is that the siii¬ cone film builds up with each subesquent treatment, i.e. brushing of the teeth, In this way, regular brushing of the teeth provides a more continuous and possible thicket film which provides added protection against cavities and tartar formation. An important cosmetic advantage is that teeth treated with the composions thus stated have a more pronoun¬ ced shine or sheen. The dimethylpolysiloxane used in the compositions usually has a viscosity in the range of 40 to 100 000 centistokes at 25°C and the preferred viscosity range is 200 - 5 000. Suitable materials are made by General Electric under the Trade Names SF-96. The two GB Publications mentioned above discloses the use of siiicone oil in the dentifrice in order to cause a siiicone oil film onto the teeth surface, which should cause condi¬ tions for solving the problems of dental decay, cavities and non-adherent to foreign materials. t_»UIYU.1A___ UJ: T-1-. INVJ_,DT1U1 TECHNICAL PROBLEMS when considering the earlier state of the art as de¬ scribed above, it will be seen that a technical problem resides in the provision of conditions, with the aid of simple means, whereby a novel or known highly abrasive dentifrice or toothpaste can be given a higher polishing effect and a lower abrasive effect while retaining the desired cleaning effect of the dentifrice, by adding a selected, adapted additive thereto. It will also be seen that a technical problem resides in the ability to realize the limit vaiues within which the additive shall lie in order to provide noticeable re¬ sults in the aforesaid respect. It will also be seen that a technical problem resides in choosing from earlier known substances a substance whose composition and polishing properties will render it suitable for admixture with toothpastes and other denti¬ frices. When considering the earlier known prior art as des¬ cribed above, it will be seen that a technical problem resides in the ability to realize within which limit values siiicone oil shall be added to a dentifrice in order to achieve a lower abrading effect and a higher polishing effect. Another technical problem is one of realizing the limit values in which siiicone oil shall be added to a denti¬ frice in order to ensure that a thin film of siiicone oil will be applied to the surfaces of the teeth, the tooth enamel and the dentine surfaces, when brushed in a typical manner. A further technical problem is one of realizing that, in practice, the upper limit value is governed by the fact that an excessive quantity of siiicone oil will result in an excessively thin, fiowable dentifrice, and that the lower iimit is governed by the fact that a given percentage of siiicone oil, at least more than 3%, is required in order to reduce the abrading effect of the dentifrice and in order to obtain an effective siiicone film without undue effort. From the starting point of known dentifrice mixtures or compositions, another technical' problem is one of real¬ izing the technical effect obtained with an adapted admixture of at least more than 5% and less than 20% siiicone oil. Naturally, another technical problem is one of realizing the significance of suitable relationships between a special polishing substance and an available abrasive, so that these substances are present in an homogenous mixture. Considering now the prior art discussed above and the steps taken towards the application of a siiicone film onto and over the teeth surfaces for reducing dental decay, cavities and causing non-adherent to foreign materials it must be se as a technical problem to combine these features with the features that siiicone oil or the like also, when mixed int and with the dentifrice, is reducing the abrasion of the tooth-surface and causing a tooth-surface polishing effect. It is a technical problem to realize that a proper addition of siiicone oil can be made to a normal and/or standardized dentifrice with an abrasive agent of any kind offering a predetermined reduction in the abrasion of the tooth-surfac It is also a technical problem to realize that an already known and awailable tooth-paste or dentifrice can now be available with "full", "medium" or "small" abrasion-effect only by adding different and small amounts of siiicone oil and where the amount is choosen within small quantities. SOLUTION With the intention of solving one or more of the afore¬ said technical problems, the present invention is based on a brush-applied dentifrice. This dentifrice may, advantageously, be any earlier known dentifrice, such as toothpaste, containing all of the aforesaid ingredients. According to the invention, the dentifrice, which may be a known toothpaste, is admixed with a substance which has tooth-polishing properties and tooth-abrasion reduc¬ ing properties, in an amount corresponding to 5-20%. According to proposed embodiments, the aforesaid sub¬ stance is comprised totally or partially of siiicone oil, or is comprised of " a substance whose polishing properties, among other properties, completely or par¬ tially correspond to the properties of siiicone oil. It is also proposed that the percentage of substance used shall be weil mixed with the percentage of abrasive present. It is particularly proposed that the substance shall be present in an amount corresponding to 8-12%, normally 9-11%. AUVAMTΛIjJt--- ϊhose advantages primarily afforded by the inventive brush-applied dentifrice, i.e. teeth-cleaning agent, reside in the addition of a substance which enhances the polishing effect, and therewith the shine of the teeth while reducing the extent to which the surfaces of the teeth are abraded. In addition, the choice of siiicone oil as the substance used results in clean dental surfaces being coated with a film of siiicone oil, which has been found advanta¬ geous as a substrate surface on which the pellicle layer forms. The inventive dentifrice is primarily characterized by the characteristic features set forth in the character¬ izing clause of the following Claim 1. B l_._. DCSCKIPTIGN OJ, TH___ D AWINGS A preferred embodiment of apparatus capable of illustrating the features significant of the present invention will now be described in detail with reference to the accompanying drawings and also with reference to test results, in which Figure 1 is a greatiy simplified illustration or a laser refiectometer; Figure 2 illustrates the rate at which teeth are abrad¬ ed when using a known toothpaste, in dependence on the addition of siiicone oil in varied amounts; and Figure 3 is a diagram which illustrates the abrasive- ness of different toothpastes, some of which contain a homogenous admixture of 10% siiicone oil and some of which contain no oil at ail. BjaST MODj-ϋS OF CAR YING OUT HJ INVENTION Figure i is a greatiy simplified illustration of a laser refIectometer !! L" which is comprised of a helium-neon gas laser having a wavelength of 632.8 nm, a power output of 4 mW and a beam diameter of 0.81 mm. The illustrated apparatus also includes a photocell Si P !t , which is of the kind sold by Siemens and designated BF-64 and which has a circular orifice and a diameter of 5.3 mm. The electronic circuit "E" utilizes a current/ voltage converter with amplifier. The illustrated volt¬ meter V is a Simson digital multimeter model, designated 461A. The apparatus used is described in an article "Denti¬ frice abrasivity. The use of laser beams for comparative studies in vitro of surface changes" by κedmalm, G & Ryden, H, Swed. Dent. J. 1979, 3. 91-100. Reference is made to Swedish Patent Specification 368 309 for a deeper understanding of the manner in which the illustrated apparatus is used. The invention is based on the addition of a substance, such as siiicone oil, which will provide a greater polishing effect and a lower abrasive effect and which will also form a protective coating or a protective film on clean tooth surfaces and dentinal surfaces which is favourable to the subsequent instantaneous formation of a pellicle layer. Referring now to Figure 2, the y-axis of the illustrated diagram shows the rate of abrasion (measured as a reduc¬ tion in light reflected by a glossy surface) as a func¬ tion of the amount of siiicone oil present in tooth¬ pastes, or dentifrices, which have been thinned by adding different quantities of siiicone oil, from 0 to 15%, and at one and the same abrasion speed and time duration. It will be clearly seen from Figure 2 that in the case of the toothpaste which contains 5% siiicone oil, only a certain noticeable reduction is obtained in the abrasion rate. A more noticeable reduction is obtained with the toothpastes which contain 5 and 10% siiicone oil. A certain reduction is also obtained with those tooth¬ pastes which contain 12-15% siiicone oil, although this reduction is difficult to discern. Thus, it can be expected that a high percentage of siiicone oil will reduce the rate of abrasion and also produce a well-developed film of siiicone oil on clean dental surfaces. It can also be expected that a toothpaste which has been softened by a siiicone oil addition can be made firmer by adding an appropriate amount of thickener. The amount of siiicone oil used will thus be opposed by several contradictory requirements. The measuring method used in this regard is based on the fact that the lustre, or amount of light reflected, will decrease with increased abrasion, starting from an initial stage, and that the abrasive effect is in rela¬ tion to the extent by which the reflection of light is reduced. A steady state light-reflection value will serve as a measurement of the observed polishing effect. Figure 3 illustrates the reduction in light reflection I./I as a function of time, t o The aforedescribed method used to measure abrasion means that the first hour will be of most interest and the most significant in which to observe the results achieved. However, ail tests carried out on dentifrice agents that contained an addition of 10% siiicone oil provided a noticeable reduction in abrasion. The addition of 10% siiicone oil is thought to be suffi¬ cient with regard to obtaining a well-formed and dis¬ tributed siiicone film on clean dental surfaces. The properties of the inventive dentifrice will now be illustrated in more detail by comparing the inventive dentifrice with four different known toothpastes. The toothpastes referenced A are commercially available and are sold in tubes, whereas the toothpastes referenced B are available toothpastes according to A but contain an addition of 10 percent by weight pure siiicone oil. The siiicone oil is comprised of 10% polydimethyl siloxane (200 cs). The various toothpastes are designat¬ ed as follows: PERCENTAGE TOOTHPASTES ABRASIVES SILICONS OIL 1. Solidox mint, A (silicon dioxide) 2. Solidox mint, B 10? 3. Clinomyn, A (aluminium silicate, 0.2? calcium carbonate) 4. Clinomyn, B (dicalcium phosphate 10? dihydrate) 5. Colgate, A (dicalcium phosphate dihydrate and 6. Colgate, B silicon dioxide) 10% 7. Colgate gel, A (silicon dioxide and dicalcium 8. Colgate gel, B phosphate) 10% The experiment was performed with the aid of acryl plates produced from polymethylmethacrylate (plexiglass XT) having a density of 1.18, a ball hardness HD, 10 sec. , 190 Mpa with light transmission within the range of 380-720 n , 92% and reflection losses 4%. The toothbrush used comprised nylon material 6-12 and had a diameter of 0.23 mm and a length of 10-12 mm. The toothbrush was profiled with four rows and 34 bristle bundles, approximately 32 bristles to each bundle, a thread dimension of 27 x 9.5 mm and rounded bristle ends. The toothbrush was fitted to a brushing machine which moved backwards and forwards through a distance of 85 mm and at a speed of 2,000 double strokes per hour and exerted a force of 2.35 N. The apparatus had six brush positions and each brush collected an aqueous slurry of toothpaste from a tray placed in the location of the test plates. New brushes were fitted at the end of each test and the machine and the diameters of the respective brushes were checked. Laser Measuring Prior to beginning the experiment, the laser was acti¬ vated for one hour in order to stabilize light intensi¬ ty. The total light, reflected and transmitted from five untreated acryl plates was registered initially. The plates were placed in the brushing machine and there brushed for six hours, corresponding to 12,000 double strokes. The slurry used comprised 25 g toothpaste and 50 ml water and was now placed in respective trays. The plates were removed, cleaned with lukewarm water, dried and placed in the laser equipment every hour, and the light intensity was again measured. The slurry was renewed after each measuring process. The abrasion value, corresponding to the change in the light reflection and the stationary value (loo), i.e. the value at which equilibrium is to be expected in the surface structure, was established after normalization by dividing by "I " with the aid of the computer program "Minsq" and with the aid of the following equation: where I, is the intensity of the reflected light regis¬ tered by the photocell after "t" hours. I is the ini¬ tial value of I . SURFACE MEASUREMENTS This measuring process was effected with the aid of a Hommel Tester T1000 surface reflection meter, the sur¬ face parameters of which were in accordance with DIN 4768. The apparatus was calibrated with the aid of a standard surface sample. All plates were measured after being brushed with toothpaste. The results were calculated as surface smoothing values, so-called Ra-values. The results showed that toothpastes to which siiicone oil had been added had the highest polishing effect. The aforesaid percentages are primarily percentages by weight. In certain compositions, percent by volume can be preferred. In Figure 3, the reduction in light reflection I. /I is t o a function of time. Thus, all tests showed that an addition of 10% siiicone oil results in reduced abrasion and in a higher polish¬ ing effect. It will be understood that the invention is not restric¬ ted to the aforedescribed and illustrated exemplifying embodiments thereof and that modifications can be made within the scope of the invention defined in the follow¬ ing Claims.

Claims: CLAIMS 1. A brush-applied dentifrice which conveniently con¬ tains an abrasive, a thickener, colourant, surface tension-reducing agent and/or preserving agent among other things, c h a r a c t e r i z e d in that 5-20% of the dentifrice is comprised of a tooth-surface pol¬ ishing and abrasion-reducing substance. 2. An agent according to Claim 1, c h a r a c ¬ t e r i z e d in that the substance is comprised total¬ ly or partially of siiicone oil, or of a substance whose qualities include polishing properties which correspond totally or partially to the properties of siiicone oil. 3. An agent according to Claim 1, c h a r a c ¬ t e r i z e d in that the percentage of substance used is well mixed with the percentage of abrasive present. 4. An agent according to Claim .1, c h a r a c ¬ t e r i z e d in that 5-12% is comprised of said sub¬ stance, preferably 7-11%. 5. An agent according to Claim 2, c h a r a c ¬ t e r i z e d in that 8-10% is comprised of said substance. 6. The use of siiicone oil in a brush-appliable dentifrice containing a mixture of a portion of an abrasive with at least a portion of a thickner, colourant, surface tensionin reducing agent and/or preserving agent, in order to achieve tooth-surface polishing properties and abrasion-reducing properties, c h a r a c t e r i z e d in that a portion 5 - 20% of said dentifrice comprises totally or partialy of siiicone oil. 7. The use of siiicone oil as stated in claim 6, c h a¬ r a c t e r i z e d in that 5 - 12% of said portion compri ses of siiicone oil. 8. The use of siiicone oil as stated in claim 6, c h a¬ r a c t e r i z e d in that at high fractions of siiicone oil the franction or concentration of thickening agent is chosen for a final consistency of the dentifrice.

Inventors: JOHANSEN GUNNAR, REDMALM GORAN, ROELLA GUNNAR, RYDEN HANS, JOHANSEN, GUNNAR, REDMALM, GORAN, ROELLA, GUNNAR, RYDEN, HANS
Applicants: JOHANSEN GUNNAR, REDMALM GORAN, ROELLA GUNNAR, RYDEN HANS, JOHANSEN, GUNNAR, REDMALM, GORAN, ROELLA, GUNNAR, RYDEN, HANS
Application year: 1993
Main classification: A61K7
IPC codes: A61K8, A61Q11