The present invention refers to compositions useful as tooth-pastes capable of removing dental plaque.

Tooth pastes, now available on the market, commonly comprise, beside deionised water: a) an abrasive agent to remove the protein film formed on the tooth surface, without any damaging of the tooth enamel. Among the abrasive agents the following can be mentioned: dihydrate calcium phosphate, calcium carbonate, hydrated alumina and silica: b) a preferably anionic surfactant agent to help the frothing and making more pleasant the use of tooth-paste. Among said surfactant agents, lauryl sulphate, lauryl sarcosinate or sodium glutamate are the more commonly used; c) gelating compounds restraining the tooth paste contained water from separating in order to insure long time tooth paste softness. Such products consist generally of glycerol, sorbitol, propylen glycol; d) products capable of maintaining the abrasive agent within the suspension. Some example of the above products are: cellulose derivatives as hydroxymethylcellulose, carboxymethylcellulose, cellulose ethers as well as pyrogenic silica, carrageenans.

Other products are generally present in tooth pastes i. e. aromas, sweetening agents, colours, preservatives, anticorrosion agents when use is made of metal containers.

Actually commercial tooth pastes further contain one or more of the following additives: whitening agents, as peroxides or persalts, anticaries agent as fluorine derivatives as well as one or more anti-plaque agents, consisting of anti-microbial anti-bacterial agents.

Therefore commercial tooth-pastes carry out a teeth and oral cavity aesthetic and hygienic conservation action due to the presence of antibacterial and anti-microbial ingredients, but they do not provide any information as to the status and the presence of the plaque on the teeth surface, on the gingivas or other zones of the oral cavity.

Commercially available are products capable to reveal the presence of the plaque on the tooth surface and other parts of the oral cavity. The plaque detection is based on the change of colour of said detectors when they come in contact with the tooth- plaque.

Other plaque detecting methods comprise the use of radiations which cause a fluorescence of the zones where the plaque does exists. Such a products and methods are carried out before or after tooth brushing, therefore it is not possible to know whether the tooth brushing goes in the direction of the complete plaque removal. In fact no information is available as to the zones wherein plaque is present in a higher concentration and where concentrate the tooth brush action, unless after the teeth brushing is over.

It would highly desirable to avail of a tooth paste that while maintaining the properties of the teeth paste comprising the present available components does not exhibit the inconveniences due to the information failure as to the existence and status of the plaque during the usual tooth cleaning treatment.

It has now been found that it is possible to overcome the above mentioned inconveniences by using a tooth paste composition that comprises, beside the known

components listed above, also a plaque detecting component, indicating the plaque existence, by an intense colour assumed by the tooth paste suspension in the oral cavity. As the tooth paste treatment proceeds, the colour indicating the plaque existence become less intense until its disappearance that means that the entire plaque has been attacked and removed by subsequent brushing treatments. The presence of the plaque detecting compound allows to predefine the teeth brushing duration and intensity depending upon the plaque presence and its concentration in the oral cavity.

It is therefore an object of the present invention a composition useful for the preparation of a new class of tooth paste or collutory capable of detecting the presence of plaque in the oral cavity, during the tooth brushing containing one or more plaque detecting agent, together with all components necessary to accomplishing a good detergent and curative activity on the teeth and furthermore allows to monitory plaque disappearance and removal degree as the teeth brushing proceeds.

The scope of the present invention is reached by means of a composition having the form of a paste of solid materials containing a small amount of water comprising: a) an abrasive agent to remove the protein film formed on the tooth surface, without any damaging of the tooth enamel; b) a preferably anionic surfactant agent to help the frothing and making more pleasant the use of tooth-paste; c) gelating compounds restraining the tooth paste contained water from separating in order to insure a long time tooth paste softness; d) products capable of maintaining the abrasive agent within the suspension; e) one or more of the following additives: whitening agents, as peroxides or persalts, anti-caries agents i. e. fluorine derivatives;

f) one or more anti-plaque agents, consisting of anti-microbial anti-bacterial ingredients; g) a component capable to detect the presence of plaque by means of an intense colour shown by the tooth-paste suspension present in the oral cavity in the course of teeth brushing operation.

Among the products useful as components of group a) the following can be mentioned: dihydrate calcium phosphate, calcium carbonate, hydrated alumina and silica.

Among the products useful as surfactant agents of group b), lauryl sulphate, lauryl sarcosinate or sodium glutamate are the more commonly used.

The materials useful as group c) components, are generally glycerol, sorbitol, propylen glycol.

Some example of compounds of group d) are: cellulose derivatives as hydroxymethylcellulose, carboxymethylcellulose, cellulose ethers as well as pyrogenic silica, carrageenans.

As abovesaid the tooth-pastes presently available on the market comprise one or more of the following additives: whitening agents as peroxides or persalts, anti-caries agents as fluorine derivatives as well as one or more anti plaque agents generally comprising anti-bacterial or anti-microbial compounds.

As plaque detector agent use can be made of any known compound which is able to assume or to make assume to the tooth-paste dispersion when used for teeth brushing an colour whose intensity depends on the existing plaque amount.

In order to better understand the advantages of the present invention some tooth pastes composition have been prepared which fall within the scope of the present invention

containing both Triclosan as anti-plaque agent and erythrosine as plaque detector.

Tooth paste composition was as follows: Silica 20% SLS or alternative anionic as lauril sarcosinate or sodium glutamate 2% Glycerol or sorbitol 30% Hydroxymethyl cellulose or Xantam Gum derivatives or Carbomer 1% Parabene mixture as preservative systems 0,3% Triclosan (Antibacterial and Antiplaque agent) 0, 2% Sodium fluoride or Sodium monofluorosulphate 1% Demineralised water 42,5% Plaque detecting agent (erythrosine or its derivatives) 3% The tooth paste prepared according to the above composition was distributed to volunteers accostumed to a different use of the tooth paste, First of all, the above persons were provided with an anti-plaque containing toothpaste, but without any plaque detector agent and said volunteers were requested to keep brushing their tooth until, according to their opinion, the plaque was totally removed. Another volunteer group were requested to continue the tooth-brush action until an observed plaque disappearance.

In both cases the tooth-brushing time was recorded.

The result are reported in the following table: Volunteers Anti-plaque agent Plaque-detector Time necessary for plaque removal Triclosan % weight erythrosine % weight estimated effective min min A 0,2 0 10-- B 0,2 3---7

C 0,2 0 11 D 0,2 3---6 E 0,2 0 10-- F 0,2 3---6, 5 The test on volunteers B, D, F and the relevant composition fall within the scope of the invention, while the results of volunteers A, C, E, testing tooth-pastes without any plaque detector are provided as comparison testes.

It appears that volunteers using compositions according to the invention are able to remove dental plaque by a selective and appropriate action on the zones of the oral cavity, whereas volunteers who did not receive the plaque detector require a longer time to remove the plaque and, in some case the removal is not complete.