Method of manufacturing tooth whitening material

ES 2 332 995 T3

DESCRIPTION

Manufacturing procedure of teeth whitening material.

Field of the invention

The present invention relates to teeth whitening material formed from a powder component and a liquid component, which is fixed in a semi-solid elastomeric texture.

Background of the invention

This invention relates generally to teeth whitening materials used by a dental professional to whiten human teeth. For a variety of reasons it has been made desirable for a person's teeth to appear shiny or "white." Society places great value on the "whiteness" of teeth.

A tooth is made up of an inner layer of dentin and an outer layer of hard enamel that is the protective layer of the tooth. The enamel layer of a tooth is naturally dull white or slightly off-white. It is this layer of enamel that can stain or discolor.

Many substances that a person encounters or comes into contact with on a daily basis can "stain" or reduce the "whiteness" of their teeth. In particular, food, tobacco products, and liquids consumed tend to stain teeth. These products or substances tend to accumulate in the enamel layer of the tooth and form a film surface on the teeth. These staining and discoloration substances can later permeate the enamel layer. This problem occurs gradually over many years, but causes a noticeable discoloration of the tooth enamel. Some pharmaceuticals, diseases and environmental factors can also have the effect of discoloration of the teeth. As long as discolored teeth remain healthy and do not pose any health risks or problems, a product or substance that will whiten discolored teeth would be advantageous.

It is known in the art to provide compositions containing hydrogen peroxide and to bring a patient's teeth into contact with the composition. Prolonged contact will brighten and whiten stained teeth. Because many known peroxide compositions are viscous or even liquid, it has become common practice to provide a dental tray molded to the patient's dentition to hold the rinse material in place long enough to rinse. Without the tray, the rinse material flows out of place or is degraded and removed by saliva.

Whitening compositions can be thought of as belonging to two types: office supplies and take-home supplies. Dental professionals can perform treatment in the office, while take-home materials are designed to be administered by the patients themselves. As expected, office treatments can be accomplished using rinse compositions that have higher peroxide concentrations compared to take-home materials. This is for obvious security reasons.

Tooth whitening systems hitherto known in the art have been effective in whitening teeth. However, up to now there has been a requirement that the dental tray used be closely configured according to the dentition. Otherwise, the effects of saliva observed above are combined. An illustrative tooth whitening material employing a dental tray is shown, for example, in US Patent No. Re. 34,196. However, it would be desirable to have dental material that does not require a dental tray. Therefore, there is a need for such an improved tooth whitening material.

EP-A-0,516,872 discloses dental whitening compositions comprising a concentrated aqueous solution of hydrogen peroxide (at least 30%) and, suspended therein, a non-aqueous component comprising 50 to 80% of silica particles and may also comprise Gantrez MS-955 (mixed sodium / calcium salt of a methyl vinyl ether / maleic anhydride copolymer). The compositions take the form of pastes or gels and are applied directly to the teeth.

Brief description of the invention

Therefore, an object of the present invention is to provide a tooth whitening composition from a solid or powder component and a liquid component. When mixed, the resulting composition will set to elastomeric quality in about 1 to about 5 minutes.

The present invention is set forth in the claims.

Brief description of the drawings

Fig. 1 is a perspective view of a dual syringe mixing apparatus suitable for use in the present invention to mix a powder component and a liquid component, and then dispense the material as required;

ES 2 332 995 T3 fig. 2 is a partially schematic top plan view of a dental arch in place, employing a backing sheet.

Preferred embodiments for carrying out the invention

The present invention uses a two component tooth whitening material that is intended for use by a dental professional as opposed to use by a non-professional patient. The material employs hydrogen peroxide in concentrations preferably from about 30 to about 35% by weight. The material is prepackaged with a solid or powder component separated from a liquid component. The liquid component contains the hydrogen peroxide in water, and may contain other conventional components such as stabilizers, flavoring agents or the like.

The liquid component may also comprise other conventional bleaching agents such as carbamide peroxide, if desired.

The powder component preferably comprises mixed sodium / calcium salts of poly (methyl vinyl ether / maleic anhydride). Such a polymer is available, for example, from International Specialty Products as Gantrez. A particularly useful variety of Gantrez is Gantrez MS-955.

The two components, liquid and powder, are combined in proportions of 20 to 80 parts by weight of hydrogen peroxide and 20 to 80 parts by weight of Gantrez. Preferably, the Gantrez is mixed with titanium dioxide. Preferred mixtures of Gantrez and titanium dioxide include from about 1 to about 99 parts by weight of Gantrez and from 99 to about 1 part by weight of titanium dioxide.

A preferred embodiment of the present invention includes from about 40 to about 60 parts by weight of hydrogen peroxide and from about 60 to about 40 parts by weight of a 99: 1 Gantrez / titanium dioxide powder mixture. The two parts are mixed together for about 10 to about 60 seconds, and the resulting mixture is a creamy white or off-white material. The material sets into a solid or semi-solid elastomeric or rubbery texture between about 1 and about 5 minutes. Before fixing, the material can be placed on a dental tray, or applied directly to the dentition without the use of a tray. Once the material has set, the tray, if used, can be left in place or removed.

Fig. 1 shows a preferred way of packaging the materials used in the present invention. The package 10 of FIG. 1 includes a first syringe 11 connected at its outlet end 12 to the outlet end 13 of a second syringe 14. One of the syringes 11 or 14 contains the powder component as described above, while the other contains the liquid component. . Any method of selectively preventing fluid communication between syringes 11 and 14 is within the scope of the invention. For example, a key 20 can be used. In this way, materials can be packaged, supplied and stored separately until needed. When needed, the interiors of the syringes 11 and 14 are brought into fluid communication, for example using a conventional wrench 20. Keys such as key 20 are well known in the art and the internal function of key 20 need not be specifically described.

Once the interior of syringe 11 is in fluid communication with the interior of syringe 14, the user manually depresses one of the plungers 21 of syringes 11 and 14. Consequently, the contents of each syringe 11 and 14 are caused to flow alternately. towards that of the other, making the mixture.

When mixing is complete, the syringes are separated with the mixture contained in a syringe 11 or 14. That syringe 11 or 14 is then used to dispense the mixture as required.

According to fig. 2, the bleaching material 40, as described above, is mixed either by shaking in a container or using syringes 11 and 14. Before the material has set as described above, it is decanted into a mold to form any shape. desired, such as a rectangular band as shown in the drawing, or any other shape, and is at least partially fixed. A separating or reinforcing sheet 41 is then pressed into the at least partially fixed material 40. The sheet 41 may be of any material, but is preferably flexible enough to bend around the curvature of the dentition as depicted in FIG. . 2, but not so flexible that it does not physically support the material 40.

The combined sheet 41 and material 40 are then placed over the dentition 50 having the teeth 51 for bleaching such that the material 40 is brought into superior contact with the desired tooth or tooth portions. It will be appreciated that the material 40 will fill any interstitial gaps between individual teeth, as well as any cracks, fissures, or other dentition profiles, as also depicted in the drawings. Sheet 41 does not conform to the shape of a given tooth, although it is curved for proper placement of material 40 as described. When treatment is complete, sheet 41 and material 40 can be removed simply by peeling or otherwise removing them from the patient's dentition.