Dentifrice
The present invention relates to a dentifrice for removing plaque which is employed as an actively prophylactic, hygienically cosmetic and healing preparation in daily use and in stomatologic practice. 
     BACKGROUND OF THE INVENTION 
     It is known that cellulose powder with a particle size of 1 to 350 micrometers can be used for direct tableting of medications. This eliminates additional auxiliary measures and the use of additional adjuvants based on the specific rheologic parameters of powdery cellulose. 
     The selection of suitable agents which effectively eliminate plaque is essential in the production of hygienic and prophylactic agents of the buccal cavity such as the dentifrices used daily, with varying active prophylactic and cosmetic effect. 
     To this end, it is known that scouring agents such as calcium carbonate, dicalcium phosphate dihydrate, among others, are used which, even though they eliminate the plaque on the teeth due to their mechanical action, damage at the same time the hard enamel to a varying degree. 
     The use of microcrystalline cellulose such as e.g. AVICEL PH 105 as abrasive component in toothpastes is known. See published French application 2,625,676. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide an effective, plaque-cleaning agent for the buccal cavity which does not cause any undesired side effects on the hard enamel and which preserves the normal physiological state of the buccal cavity. 
     These and other objects are achieved with a dentifrice consisting of the customary known components of a dentifrice but which contains cellulose powder instead of known abrasive components as the cleaning agent. 
     The cellulose powder can have a particle size of 1 to 300 micrometers, preferably of 35 to 160 micrometers and can be contained in the dentifrice in an amount of 1 to 25% by weight, preferably of 10 to 20% by weight. 
     In one embodiment of the invention, microfine powdery cellulose can be used as the sole cleaning body. Other additional active substances which are plaque-removing, plaque-preventing or infection-inhibiting can be eliminated. 
     A cellulose powder which is sold under the name ELCEMA® P 050 and P 100 and has the following physical properties is preferred: 
     Native, high-percentage α cellulose consisting of 1,3-β-glycosidically linked D-glucose molecules with n=primarily around 500 and above. 
     Fine white powder 
     without taste or odor 
     insoluble in water 
     insoluble in dilute acids 
     swelling in dilute alkalies 
     insoluble in organic solvents 
     
         ______________________________________                                    
ELCEMA ® type  P 100      P 050                                       
______________________________________                                    
Structure          powder     powder                                      
Particle size in   50-150     40-70                                       
microns approx.                                                           
Bulk weight when bagged g/l                                               
                   approx. 220                                            
                              approx. 230                                 
pH                 5.0-7.5    5.0-7.5                                     
Refractive index   1.55       1.55                                        
Density g/cm.sup.3 approx. 1.5                                            
                              approx. 1.5                                 
______________________________________                                    
 
    
     
         ______________________________________                                    
Drying loss 2 h/105° C.                                            
                        &lt;6%                                               
Residue on ignition 2 h/850° C.                                    
                        &lt;0.3%                                             
Water-soluble components                                                  
                        &lt;1.0%                                             
Ether-soluble components                                                  
                        &lt;0.15%                                            
Calcium ions            &lt;0.05%                                            
Chloride ions           &lt;0.05%                                            
Sulfate ions            &lt;0.05%                                            
Heavy-metal ions as Pb  &lt;10 ppm                                           
Zn                      &lt;2 ppm                                            
As                      &lt;1 ppm                                            
Cr                      &lt;1 ppm                                            
Fe                      &lt;10 ppm                                           
Cu                      &lt;1 ppm                                            
______________________________________                                    
 
    
     Demonstration of identity 
     The substance dissolves slowly in ammoniacal copper oxide solution. No violet or blue coloration occurs with iodine solution in aqueous dispersion. 
     The cellulose powder which can be used in accordance with the invention is described in the &#34;Deutsches Arzneibuch&#34;, 9th edition, 1986 (DAB9) on page 621, in the USP XXII NF XVII (The United States Pharmacopeia, The National Formulary), 1990, page 1916 and in the European Pharmacopoeia, 2nd edition, part. II, eighth edition 1984, page 315. 
     It has been determined in tests performed with dentifrices in accordance with the invention, with cellulose powder which exhibited a particle size of 1 to 350 micrometers, that they effectively eliminate plaque, prevent it from reforming and act in an infection-inhibiting manner in the buccal cavity when used in amounts of 1 to 25% by weight, preferably 10 to 20% by weight in various compositions of dentifrices. In addition, there is compatibility with all biologically active components such as: Fluoride ions, zinc ions chemical therapeutic agents, enzymes, components of natural origin which can be used in addition, if necessary, for a greater inhibition of the development of plaque and which also can exhibit an infection-inhibiting action. 
     The cellulose powder is chemically inert and at the same time physiologically compatible. These properties make it possible to use it in oral hygiene formulations whose contents are incompatible with known cleaning agents. It is known, for example, that fluorine compounds retain their action only for a limited time in combination with known cleaning agents such as calcium carbonate, di-calcium phosphate-di-hydrate and others. In the combination of the cellulose powder with dentifrices containing fluoride ions, dentifrices are formulated which retain the activity of the fluoride for an unlimited time span, at least, however, for 18 months. This makes it possible to produce dentifrices without having to take into consideration the previously necessary limitations on their ability to be stored. 
     In a preferred embodiment of the invention the cellulose powder can be used in fluorine-containing dentifrices. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The invention is illustrated in the following examples: 
     
         ______________________________________                                    
Example 1        % by weight                                              
______________________________________                                    
ELCEMA ® P 100                                                        
                 10.0                                                     
Glycerol         20.0                                                     
Aerosil ® 200                                                         
                 1.0                                                      
Blanose          1.5                                                      
Sweetener        1.0                                                      
Preservative     0.5                                                      
Aroma substance  1.0                                                      
Foaming agent    1.0                                                      
Water up to      100                                                      
______________________________________                                    
 
    
     
         ______________________________________                                    
Example 2        % by weight                                              
______________________________________                                    
ELCEMA ® P 100                                                        
                 20.0                                                     
Glycerol         10.0                                                     
Aerosil ® 200                                                         
                 1.0                                                      
Blanose          1.5                                                      
Sweetener        1.0                                                      
Preservative     0.5                                                      
Aroma substance  1.0                                                      
Foaming agent    1.5                                                      
Water up to      100                                                      
______________________________________                                    
 
    
     
         ______________________________________                                    
Example 3        % by weight                                              
______________________________________                                    
ELCEMA ® P 050                                                        
                 15.0                                                     
Glycerol         20.0                                                     
Aerosil ® 200                                                         
                 3.0                                                      
Blanose          1.5                                                      
Preservative     0.5                                                      
Aroma substance  1.0                                                      
Sweetener        1.0                                                      
Foaming agent    1.5                                                      
Water up to      100                                                      
______________________________________                                    
 
    
     The substances used in the examples can be characterized as follows: 
     Aerosil® 200 is a pyrogenically produced silica with a BET surface of 200±25 m 2  /g. 
     Blanose is a sodium carboxymethylcellulose used as a binder. 
     The sweetener is saccharine. 
     The preservative is Nipagin and Nipasol, which constitutes 0.1% by weight together, or sodium benzoicum (0.5% by weight). 
     The aroma substance is peppermint oil. 
     The foaming agent is sodium lauryl sulfate. ELCEMA® P 100 or P 050 is a native, high-percentage α-cellulose consisting of 1,4-β-glycosidically linked D-glucose molecules with n=primarily around 500 and above. Fine white powder 
     without taste or odor 
     insoluble in water 
     insoluble in dilute acids 
     swelling in dilute alkalies 
     insoluble in organic solvents 
     
         ______________________________________                                    
ELCEMA ® type                                                         
                P 100       P 050                                         
______________________________________                                    
Structure       powder      powder                                        
Particle size in                                                          
                50-150      40-70 Bulk                                    
microns approx.                                                           
weight when     approx. 220 approx. 230                                   
bagged g/l                                                                
pH              5.0-7.5     5.0-7.5                                       
Refractive index                                                          
                1.55        1.55                                          
Density g/cm.sup.3                                                        
                approx. 1.5 approx. 1.5                                   
______________________________________                                    
 
    
     
         ______________________________________                                    
Drying loss 2 h/105° C.                                            
                        &lt;6%                                               
Residue on ignition 2 h/850° C.                                    
                        &lt;0.3%                                             
Water-soluble components                                                  
                        &lt;1.0%                                             
Ether-soluble components                                                  
                        &lt;0.15%                                            
Calcium ions            &lt;0.05%                                            
Chloride ions           &lt;0.05%                                            
Sulfate ions            &lt;0.05%                                            
Heavy-metal ions as Pb  &lt;10 ppm                                           
Zn                      &lt;2 ppm                                            
As                      &lt;1 ppm                                            
Cr                      &lt;1 ppm                                            
Fe                      &lt;10 ppm                                           
Cu                      &lt;1 ppm                                            
______________________________________                                    
 
    
     Demonstration of identity 
     The substance dissolves slowly in ammoniacal copper oxide solution. No violet or blue coloration occurs with iodine solution in aqueous dispersion. 
     In order to test the chemical purity of ELCEMA®, the following test methods of the following pharmacopoeias can be used: 
     &#34;Deutsches Arzneibuch&#34;, 9th edition, 1986 (DAB9), page 621, 
     USP XXII NF XVII (The United States Pharmacopeia, The National Formulary), 1990, page 1916 
     European Pharmacopoeia, 2nd edition, part. II, eighth edition, 1984, page 315. 
     The following activities are investigated in the clinical testing of the dentifrice: 
     Plaque removal, plaque prevention and inhibition of inflammation. 
     The testing is carried out on 40 persons, 25 to 35 years of age. The persons tested are healthy in body, without deformation of face and jaw, without caries, without fillings in their teeth and with slightly defined catarrhal gingivitis. A preliminary hygienic preparation is carried out by removing plaque and tartar. The test begins three days after this preliminary treatment and 12 hours after the last brushing of the teeth. The following values are determined: 
     OHI-S according to Green and Vermillion 
     PMA according to Massler and Schour 
     The number of migrated leucocytes, the flaked-off epithelial cells, the erythrocytes in the mouth liquid according to Jasinovski. 
     The monitoring of brushing takes place according to the instructions in accordance with &#34;Methoden fur die klinische Studie von Zahnpasten&#34;, Moscow-Sofia, 1980. 
     The test is started with the registration of the PL plaque index and the GI inflammation index. 
     The plaque removal and the plaque prevention are measured according to the following method: 
     The test groups and control groups clean their teeth regularly in the course of 4 weeks with toothpaste using new toothbrushes. The teeth are cleaned twice a day for three minutes per time under supervision. The evening brushing is carried out on all tooth surfaces with intensive horizontal, vertical and circular motions. 
     10 to 12 brushes are used in each of the two sections: ##STR1## 
     The registration of the plaque index is carried out at the start of the test (diagnostic index) on a tooth which is not brushed for one night, and at the end of each week. The plaque is dyed by sucking on a standard dyeing tablet until completely dissolved. The plaque index is determined according to the method of Green Vermillion (simple index). 
     The plaque coating of the vestibular surfaces of ##EQU1## becomes, just as the coating of the intermediary spaces as well as the coating of the surfaces located on the tongue side with a value of --0--no plaque detected 
     --1--plaque on 1/3 of the tooth surface 
     --2--plaque on 2/3 of the tooth surface 
     --3--plaque on the entire tooth surface 
     The plaque is determined after 1 to 4 weeks in percent relative to the original state. 
     The degree of inflammation is carried out on 20 test persons who participate in the plaque test and exhibit a slightly defined, chronic gingivitis. 
     The PMA index is determined at the start and after 1 to 4 weeks. The gums are treated with J 2  -KJ solution according to the method of Svrakov-Pissarev and the inflammation determined around ##EQU2## in accordance with the following values: --0--no inflammation observed 
     --1--gingival papilla inflamed 
     The PMA index is compared after 1 to 4 weeks in percent to the initial state. The values determined for the dentifrice of the invention are compared with the values of known dentifrices determined in parallel. The following results are obtained: 
     
         ______________________________________                                    
                                  Inflammation-                           
                                  inhibiting                              
Dentifrice with                                                           
               Plaque   Plaque    effect in the                           
cleaning bodies                                                           
               removal  prevention                                        
                                  buccal cavity                           
______________________________________                                    
1.  Calcium carbonate                                                     
                   32.38%   11.03%  5-10%                                 
2.  Dicalcium phosphate                                                   
                   42.13%   10.18%  5-10%                                 
    dehydrate                                                             
    (Benckiser-Hoechst)                                                   
3.  Precipitated silica                                                   
                   38.52%   10.15%  5-10%                                 
    (Sident ® 9, Degussa)                                             
4.  Microcrystalline                                                      
                   32.15%   5.12%   5-10%                                 
    cellulose (Micricel)                                                  
5.  Cellulose powder                                                      
                   78.16%   20.04%  28-33%                                
    (Elcema ®, Degussa)                                               
______________________________________                                    
 
    
     The table shows that dentifrice 5 with ELCEMA® (cellulose powder according to the invention) has a surprisingly high plaque-removing action in comparison to dentifrices 1, 2, 3 and 4. Dentifrice 5 also clearly exceeds dentifrice 4, which contains microcrystalline cellulose (Microcel) according to the state of the art. 
     The unexpectedly high values for the plaque-preventing effect and the inflammation-inhibiting effect are especially surprising. In addition, a healing action occurs in the buccal cavity. 
     The microcrystalline cellulose Micricel used in dentifrice 4 is the same product as AVICEL. AVICEL is a microcrystalline cellulose which was partially purified and depolymerized before the spray drying (cf. The National Formulary XIII edition, monograph 43). 
     The stability test of dentifrices containing fluoride ions which contain cellulose powder as abrasive component carried out with the aid of accelerated aging methods and using the Arhenius equation shows that in dentifrices with sodium fluoride and with sodium monofluorophosphate, the active fluorine and monofluorophosphate ions retain their quantity unchanged for a time span of more than 3 to 4 years.