WO2008019870A1

WO2008019870A1 - Method and device for whitening teeth

Info

Publication number: WO2008019870A1
Application number: PCT/EP2007/007293
Authority: WO
Inventors: Bruno Pregenzer; Alfred Konzett; Johann Wernisch; Johann Pingitzer; Sebastian Geiger; Jörg WERNISCH
Original assignee: Bruno Pregenzer; Alfred Konzett; Johann Wernisch; Johann Pingitzer; Sebastian Geiger; Wernisch Joerg
Priority date: 2006-08-17
Filing date: 2007-08-17
Publication date: 2008-02-21
Also published as: AT504150B1; AT504150A1

Abstract

The invention relates to a method for whitening teeth and to a whitening device which is configured like a toothbrush, the working head of which comprises a soft structure, in particular, in the form of a field of bristles, optionally, also in the form of a round-shaped sponge or flow structure and an illuminating device with which the whitening agent activated by the light on the soft structure can radiate onto the whitening agent. The soft structure can receive a sufficient amount of the pasty or gel-type whitening agent and, just as in normal teeth brushing, can be applied to the teeth by moving the soft structure back and forth and can be rubbed onto the teeth. Advantageously, the pressure-elastic soft structure has a flexible and pressure-elastic form in order to gently rub in the whitening agent and to prevent irritations to the gums or damage the gums and the surface of the teeth. The illuminating device integrated into the working head or the soft structure and the light radiated therefrom simultaneously activates the whitening agent

Description

Method and device for bleaching teeth

The present invention relates to a method of bleaching teeth in which a photoreactive and / or catalyable bleaching agent is applied to the teeth and activated with light. The invention further relates to a bleaching apparatus for bleaching teeth according to such a method, with an insertable into an oral cavity, connectable with a handle working head, a bristle field and / or sponge-like soft structure for Deploying and triturating such a photoreactive and / or catalyzed bleaching agent on the teeth.

Due to different dietary habits (eg through tea or coffee consumption), tobacco consumption or partly as a result of illnesses, surgical procedures, inflammations in the dental area or after a Wurzelspitzenresektion etc. discoloration of teeth can occur. Such discolorations, which usually occur on the enamel and the dentin, are disturbing for the person concerned, which is why in recent years, numerous methods for bleaching or whitening of teeth have been established in which acts on the tooth surface, a bleaching agent, in particular by redox reactions with the substances causing the discoloration brightens the tooth again. Frequently, substances are used in such processes which release radicals or atomic oxygen, for example peroxides. According to the known state of the art, a distinction is currently made between so-called home-bleaching (home-use method) and so-called in-office bleaching (performed in the doctor's office). The home-bleaching process uses weak or stronger peroxide compounds, in which the reactive oxygen or radicals are chemically driven off. Due to the chemical process, which takes place without the action of light, the enamel surface is relatively strongly attacked due to the long bleaching time of up to several hours. Such processes are also referred to as chemical bleaching. When so-called dental in-office whitening, which is performed only by dentists or dentists, the expulsion of active oxygen or radicals from the actual bleaching agent (usually strong peroxide compounds) takes place by chemical or chemical and photothermal path through the use of lamps , Since normal per-office bleaching procedures use strong peroxide compounds, the bleaching time can be shortened. Nevertheless, one can observe that the enamel is attacked by the chemicals. Additional thermal support by lamps is called photothermal bleaching. Additional heating of the bleaching agent, which is often applied as a gel, rapidly degrades the strong peroxide compounds, which further shortens the duration of the bleaching process. Although the shortened bleaching time is basically positive for the enamel, one can still occasionally observe damage to the tooth enamel. Lamp systems are usually used with high radiation power: eg halogen lamps with 380 to 500 nanometers after filtering with an intensity of 400 to 1000 mW / cm ² or plasma arc lamps (argon, xenon) with wavelengths of 430 to 505 nanometers after filtering and an intensity from 1600 to 2000 mW / cm ² . Laser bleaching processes, which are also classed as photothermal bleaching processes, use lasers with output powers of approximately 1 watt, which in comparison to a conventional 75 watt incandescent bulb causes a 100-fold increase in incident intensity. For this reason, the treatment times in laser bleaching process are about 30 to 60 sec. And a subsequent exposure time of a few minutes. In comparison to conventional chemical processes, damage to enamel is significantly reduced in photothermal processes. The disadvantage, however, that the cost of a laser are very high. In addition, the bleaching material must be tuned exactly to the laser, for example, the absorption coefficient of the bleaching agent in conjunction with the peroxidic component, so that there is no thermal overload of the tooth, in particular the pulp.

From DE 203 07 294 U1 a toothbrush-like equipment is known, which has a spangen- shaped irradiation head instead of the usual in a toothbrush bristle field. This radiation head can be pushed over the teeth and irradiates the teeth with suitable light to achieve bleaching of the teeth. In this direct irradiation without the aid of a bleaching agent, however, the above-mentioned disadvantages exist. - A -

Furthermore, various toothbrushes are known in the prior art, which have lighting devices by means of which different areas of the oral cavity including the teeth can be illuminated for different purposes, cf. DE 20 2005 015767 IM, DE 20 2004 001004 U1, DE 20 2004 004628 U1, DE 295 17 758 U1 or US Pat. No. 5,030,090. However, these known toothbrushes are not intended for bleaching the teeth; The light sources used are also in terms of wavelength range and light intensity not suitable to bring about a tooth whitening.

The present invention is therefore based on the object to provide an improved method and an improved device of the type mentioned, avoid the disadvantages of the prior art and further develop the latter in an advantageous manner. In particular, a time-saving, simple and familiar to the user handling the bleaching process is to be achieved, which nonetheless achieves an efficient tooth whitening without damage to the enamel and the gums.

According to the invention this object is achieved by a method according to claim 1 and by a device according to claim 19. Preferred embodiments of the invention are the subject of the dependent claims.

Instead of applying the bleaching agent, for example with a spatula, brush or similar instruments and then placing a bulky lighting head on the teeth in order to activate the bleaching agent, as in the prior art in a two-step process, the present invention proposes a one-step process the bleach is rubbed on the teeth and activated at the same time. According to the invention, the bleaching agent is rubbed on the teeth with a bristle-field and / or sponge-like soft structure and activated during rubbing by light of suitable wavelength and intensity emitted on the soft structure. For this purpose, a toothbrush-like bleaching apparatus is used whose working head has, on the one hand, a soft structure, in particular in the form of a bristle field. if appropriate also in the form of a bulge-like sponge or tile structure and on the other hand has a lighting device by means of which the bleach-activating of the light can be radiated onto the bleach on the soft structure. The soft structure is suitable for absorbing a sufficient amount of the preferably pasty or gel-like bleaching agent and, as in the case of normal brushing, by applying the soft structure to the teeth and rubbing them onto the teeth. Advantageously, the pressure-compliant soft structure is flexurally and compressively elastic to gently rub the bleach and to prevent irritation of the gums or even damage to the gums and the tooth surfaces. The bleaching agent is simultaneously activated by the lighting device integrated in the working head or the soft structure and the light emitted by it.

In a preferred embodiment of the invention, the activation of the bleaching agent causing light is at least partially passed through the soft structure and radiated from the soft structure in particular at its working surface. When forming the soft structure in the form of a bristle field, the light can be passed through the bristles and radiated at the bristle ends. In a further development of the invention, the soft structure may comprise a bristle field with a plurality of bristle tufts, wherein at least a portion of the bristle tufts or bristles combined into bristle tufts are designed as optical fibers. The soft structure or the bristle field forms, as it were, a part of the illumination device. The latter is such that at least a portion of the light is coupled into the bristle tuft formed as a light guide, so that it can be forwarded by these and emitted at the free ends.

Basically, the entire bristle tufts can be used to transmit light and the light can be distributed evenly over the bristle tuft field. According to an alternative advantageous development of the invention, however, an uneven light distribution over the bristle brush can also be achieved. For example, a lower light intensity can be provided at the edges of the soft structure than in the center of the soft structure in order to less strongly irradiate the gingiva coming into contact with the edges of the soft structure.

In order not only to irradiate the bleaching agent located between the tooth surface and the working surface of the soft structure, but also to activate the bleaching agent stored in the soft structure and released only gradually, it can be provided in a development of the invention that the soft structure has light channels in the form of preferably chimney-shaped recesses into which the illumination device also radiates light to activate the bleaching agent therein. The chimney-shaped recesses need not have a geometrically regular shape as in a fireplace in the strict sense, but it may also be provided irregularly shaped light channels, which are advantageously open at least to the working surface of the soft structure, so that the bleach incorporated therein can be delivered. When forming the soft structure in the form of a bristle field, the free spaces or recesses remaining between the bristle tufts can be used as light channels, i. the illumination device advantageously emits the light not only into the bristles but also into the interspaces. In a further development of the invention may be provided for this purpose at the bottom of the soft structure in the working head light exit openings, which may be formed in the form of material recesses, but especially in the form of translucent wall portions of the working head.

In order not to hinder the coupling of light into the bristle tufts in the formation of the soft structure in the form of a bristle field, it is provided in a further development of the invention that the bristle tufts are not fastened in the tufting process to the corresponding bristle carrier. Rather, alternative fasteners are provided free of anchor plate. For example, you can the bristle tufts glued or welded to the bristle carrier. According to an advantageous embodiment of the invention, for example through holes may be provided in the bristle carrier, in each of which a bristle tuft is stuffed into it, so that it easily emerges on the opposite side; There, the bristle tufts can be welded, for example, with the aid of a hot stamp, so that a favorable coupling of the light can be achieved in the bristle tufts.

Alternatively, however, the bristle tufts can each be held by an anchor plate, which sits in the walls of the recesses in the bristle carrier. In order to improve the coupling of light, the bristles turned around the anchor plate are structurally altered in this envelope region, in particular, for example, melted or cast into a coupling-in material. The portion of the bristle tufts turned over around the anchor plate advantageously has an efficient light coupling surface.

The light for activating the bleaching agent can basically be brought to the soft structure or the bristle field of the working head in various ways. According to a preferred embodiment of the invention, the illumination device may have a light source integrated into the working head. In particular, at least one light source can be arranged under a support plate bearing the soft structure on the working head. As a result, the cost of a light pipe to the working head and the losses occurring can be avoided. The light source under the support plate of the soft structure can thereby radiate the light directly into the bristle tufts which advantageously pass through the support plate. Alternatively or additionally, the carrier plate of the soft structure may be at least partially translucent, so that the light emitted by the light source can pass through the carrier plate into the overlying soft structure, in particular the light channels provided therein. According to a preferred embodiment of the invention, the light source may comprise at least one LED, which is arranged in the working head. Preferably, several LEDs can be used, in particular if the soft structure has a larger area and / or a larger area is to be exposed to light.

In order to achieve a sufficient light intensity even with small-sized and less bright light sources, in a further development of the invention, the illumination device may have a reflector which throws the light emitted by the at least one light source largely completely onto or into the soft structure. The reflector may for example consist of a mirrored film. Advantageously, the reflector is arranged on a side of the light source facing away from the soft structure, in order to deflect light thrown in the wrong direction, as it were, toward the soft structure.

As an alternative to such a light source arranged directly in the working head, the lighting device may also have a light source in the handle or in a brush tube between the handle and the working head, advantageously with a light guide operatively connected to the light source between the light source and the working head is provided to the of Light emitted light directed to the working head. This optical waveguide can in principle be designed differently, for example in the form of optical fibers integrated in the handle. Alternatively, the light guide may also be formed by the handle and / or the brush tube itself.

Regardless of the arrangement of the light source in the working head or spaced therefrom in the handle or brush tube, the power supply of the light source advantageously takes place from the handle forth. In the handle, a power supply may be arranged, which is connected via suitable electrical connection means with the light source. The power supply can for example consist of a preferably rechargeable power source in the handle. Alternatively, however, may also be an external power supply, so that in this case the power supply arranged in the handle consists essentially of a cable connection and optionally a voltage converter or -regier.

In a particularly advantageous embodiment of the invention, the soft structure for applying and triturating the bleaching agent is designed replaceable. Advantageously, the soft structure may be attached to an exchangeable removable carrier, which is detachable from the illumination device and can be releasably attached to the working head. As a result, when worn, the soft structure can be replaced without having to exchange the lighting device. Likewise, the handpiece of the bleaching apparatus may optionally be used by various persons, including the essential part of the working head; For this purpose, only every user sets "his" soft structure on the working head.

In a further development of the invention, the bleaching device has a modular structure, wherein in particular a handpiece can be provided, can be placed on the various attachment parts, for example, different attachment parts for different users, but also different essay types, such as an attachment with a sponge-like soft structure, an attachment with a bristle field, an attachment with a radiation head or the like. By virtue of such a modular construction, the bleaching apparatus can be adapted individually to the needs of the respective user, without the entire unit having to be replaced each time.

In particular, in this case, the handset on which various attachment parts can be placed, be in the form of a flashlight, which can be used as a lamp itself without an attachment and at least one light source for emitting a light cone or a directed light beam path. In principle, every lamp can be used as a light source serve, advantageously, the light source may consist of one or more LEDs. In order to achieve an efficient beam power, the light source may be associated with a reflector and / or a mirror, which focuses the light emitted by the lamp and / or throwing in a certain direction, as known in flashlights. In this case, the handpiece advantageously comprises a body which, in the region of the light exit or the light emission, has a coupling section by means of which various attachment parts can be coupled. For example, a light source surrounding, annular Kupplungsstϋck be provided.

Advantageously, the handset formed as a flashlight includes not only the light source but also their energy supply, for example in the form of rechargeable batteries, as well as control and / or actuating means for controlling the light output.

The attachable to the handpiece attachment parts may comprise a preferably tubular support piece having at one end a coupling portion for coupling to the handpiece and the other end carries the respective working head for bleaching the teeth. In particular, a soft structure of the aforementioned type can be provided as the working head. The attachment part advantageously has, as part of its illumination device, light-conducting means which guide and / or direct the light coming from the pocket-lamp-shaped handpiece to the working head in order to let the light out and act on the teeth or bleaching agent to be bleached. In this case, optical fibers or a light guide cable of the aforementioned type may be provided in the attachment. Alternatively or additionally, in the attachment part, in particular at its working-head-side end, a mirror can be provided which deflects the light radiated through the brush tube and directs it to the working head or allows it to exit through the working head in the desired direction. The illumination device is adapted to the bleaching agent with regard to its wavelength range and its light intensity in order to activate it in the desired manner when the bleaching agent is rubbed on the teeth. In principle, depending on the bleaching agent, different wavelength ranges may be required for this purpose. According to a preferred embodiment of the invention, the illumination device emits light in a wavelength range of 450 to 480 nanometers, preferably about 460 nanometers. In this wavelength range, a cooling of the irradiated bleach occurs.

It is particularly advantageous if the bleaching agent used contains at least one photocatalyst, so that the light activation of the bleaching agent can take place in the shortest possible time and in particular during the rubbing on the teeth.

It has proven particularly favorable if the photocatalyst is designed as a nanoparticle. Nanoparticles have the advantage that they have a large surface area and thus have favorable catalytic properties. In addition, they are available in large quantities and because of their small size, they have no negative mechanical properties for the tooth. Nanoparticles are particles with a diameter of about 1 nanometer to several hundred nanometers.

It is preferably provided that the photocatalyst is a semiconductor, wherein it has proven to be favorable in this case, when the nanoparticles or semiconductors from the group ZnO ₂ , Si, σ-Sn or TΪO ₂ come.

In a preferred embodiment, it is provided that the nanoparticles are anatase. Anatase is titanium dioxide with a cubic body-centered lattice, which has particularly favorable properties for the production of active oxygen. It is further provided that the nanoparticles have a diameter of about 1 nanometer to about 1 micron. Due to the tooth structure, nanoparticles with a diameter of about 100 to 500 nanometers have proven to be particularly accessible and have proven to be ideal photocatalysts for releasing active oxygen or reactive radicals.

It is further provided that the radical generator is hydrogen peroxide and / or a Peroxydabspalter, it is advantageous if in the bleach, the hydrogen peroxide in the form of an aqueous solution in a concentration of 1 to 10%, preferably of about 5%.

Although the bleaching agent has hitherto already excellent properties, it is still favorable if, in addition, a thickening agent is present, it being particularly provided that the thickening agent is an acrylate. The presence of a thickening agent makes it possible to form the bleaching agent as a gel or paste which is applied to the tooth. Conveniently, the, for example, peroxidic substance can settle in the matrix of the gel and be ideally released there due to the photocatalytic reaction.

Due to the strong oxidative reaction of hydrogen peroxide, it has proved to be advantageous if an alkaline component or a buffer substance to increase the pH is present, it is recommended that when the alkaline component or buffer substance Na ₂ CÜ ₃ , since sodium On the one hand, carbonate is only weakly alkaline and has excellent buffering properties and, moreover, is tasteless.

Peroxides have a strong tendency to decompose under high heat development: eg 2H ₂ O ₂ -> 2H ₂ O + O ₂ + 196.2 kJ. At room temperature, however, the decay rate is extremely low. One speaks of a practical resistance or a metastable state. Upon heating to higher temperatures, the peroxide decomposes rapidly, possibly explosively. onsartig. The large decay inhibition of H ₂ O ₂ is based on the fact that the first step of the thermolysis in an energy-consuming molecular cleavage in 2HO radicals consists (HOOH + 21 1 kJ -> 2HO). These then continue to react with hydrogen peroxide (HO + H ₂ O ₂ -> H ₂ O + HO ₂ , HO ₂ + H ₂ O ₂ -> H ₂ O + O ₂ + HO) to initiate a radical chain reaction. By suitable catalysts, the decomposition rate of hydrogen peroxide can be greatly increased, so that may occur at room temperature stormy oxygen evolution and high-concentration solutions because of the strong caused by the H ₂ O ₂ -Thermolyse temperature increases even explosive decay. The characteristic property of H ₂ O ₂ is in particular its oxidizing effect: H ₂ O ₂ -> H ₂ O + O or H ₂ O ₂ + 2H ⁺ + 2e ^" -> 2H ₂ O. The normal potentials for H ₂ O ₂ are in acidic solution + 1, 76 volts, in alkaline solution + 0.87 volt. therefore, it is advantageous that the bleach material is located during use in the alkaline range and, therefore, causes only a slight chemical attack. in addition, the H ₂ O ₂ in the gel in the specific case strongly diluted (about 5%), whereby a chemical attack is excluded even after very long treatment (over 1 hour) according to previous studies.

Less pronounced is the reducing effect of H ₂ O ₂ : H ₂ O ₂ - + 2H + O ₂ or H ₂ O ₂ -> 2H ⁺ + O ₂ + 2e ^~ . The normal potentials for H ₂ O ₂ in acidic solution are +0.68 volts and in alkaline solution -0.07 volts. The reducing effect thus occurs only against pronounced oxidizing agents. The bleaching of the teeth is primarily responsible for the decomposition of H ₂ O ₂ resulting atomic oxygen. The normal potentials for atomic oxygen in acidic solutions are 2.42 volts, in basic solutions 1.59 volts. When working in the basic range, a bleaching agent according to the invention has a low value of the normal potential for H ₂ O ₂ and a high value of the normal potential for oxygen. Thus, a low proportion of the chemical attack of the tooth substance is to be expected, but given a high oxidation rate for the destruction of the attachment or intercalation of the tooth. It is further provided that the nanoparticles based on the anhydrous bleach in a concentration (mass / mass) of about 1 to 90%, preferably in a concentration of 60 to 80%. More preferably, the mass fraction is about 75%. It has been found that with such high concentrations of nanoparticles, the oxygen delivery can be faster and thus the duration of treatment can be shortened.

When using a thickening agent, it is provided that the thickening agent is present in a concentration (anhydrous) of 10 to 20%, preferably about 17%. This is a cheap amount to make an ideal gel.

It is further provided that the alkaline component is present in a concentration (anhydrous) of less than 10%.

In particular, it is provided in the use of a semiconductor that light having a wavelength corresponding to the band gap of the semiconductor is used. As an alternative to the aforementioned LEDs, the light source may also be an argon laser, a KTP laser, a diode laser or a Nd-Yag laser or a CO ₂ laser whose light is transmitted to the working head via suitable optical fiber cables intended soft structure is passed. However, preferred is the aforementioned LED solution.

In a preferred embodiment, it is provided that anatase particles are irradiated with light of a wavelength in the UV-near range, preferably at a wavelength of 380 to 500 nanometers, more preferably at a wavelength of about 460 to 470 nanometers. Thermal damage to the pulp can not occur if the power of the required light sources is in the milliwatt to watt range. The gel used for the catalytic bleaching is not changed by such irradiation. The nanoparticles with semiconductor properties present in the bleach act as catalysts which upon irradiation produce active oxygen. serve. The wavelength of the radiation is determined from the energy gap of the semiconductor and depends on how much energy has to be expended to excite an electron from the non-conductive band of the semiconductor into the conductive band of the semiconductor. The energy consumed must be higher than this bandgap energy. For example, with the use of anatase nanoparticles it has been found that the most favorable wavelength at 380 to 500 nanometers is preferably 450 to 480 nanometers, which can be produced with LEDs (LED) on the market. The performance of these LEDs are in the milliwatt range and are sufficient to produce the required for the bleaching active oxygen. In addition to LEDs with different wavelengths between 320 and 500 nanometers, a conventional curing lamp for so-called composites was used in the investigations carried out. The bleaching results are comparable, ie it is also possible to use conventional curing lamps for the process according to the invention. In addition, the following semiconductors or their nanoparticles lend themselves to the use of the method according to the invention: zinc oxide (band gap 3.2 eV) with an excitation wavelength of about 387 nanometers.

Silicon (bandgap energy 1, 1 eV) corresponding to an excitation wavelength of 1127 nanometers.

σ-tin (with a band gap energy of about 0.08 eV) corresponding to an excitation wavelength of about 15 μm.

When bleaching, the laser radiation used must be higher in energy than the band gap energy of the nanoparticles, ie the gel is excited at a lower wavelength than the bandgap energy. For example, conventional lasers could also be used for the above nanoparticles. For example, argon lasers (488 to 514 nanometers), KTP lasers (532 nanometers), diode lasers (805 nanometers), and Nd-Yag lasers (1064 nanometers) are available. With a CO ₂ laser (10600 nm) an a-tin nanoparticle could be excited. The invention will be explained in more detail with reference to a preferred embodiment and associated drawings. In the drawings show:

1 is a schematic flow chart for explaining the operation of the bleaching agent provided with a photocatalyst and its reaction to light irradiation;

2 shows a perspective, schematic representation of a bleaching device designed as an electric toothbrush according to a preferred embodiment of the invention, and FIG

FIG. 3 is a sectional view of the brush head of the toothbrush of FIG. 2, showing the light source under the bristle carrier disposed in the brush head, FIG.

4 shows a perspective, schematic representation of a bleaching device with a modular construction comprising a hand-held part designed as a flashlight and an attachment part designed as an attachment brush according to a further preferred embodiment of the invention, and

Fig. 5: a fragmentary sectional view of the attachment part of Fig. 4, showing the deflection mirror in the region of the working head.

The process shown in Fig. 1 is intended to illustrate the reaction mechanism and the catalytic cycle required for bleaching. In a first step, light in the UV-near region strikes, for example, an anatase particle. Due to the semiconductor property and the excitation by the light, an electron is excited from the non-conducting band into the conducting band. The formation of an electron in the conduction band and a hole in the nonconducting band occurs. Both the electron and the electron gap migrate to the Surface. There may be a transfer of the electron to atmospheric oxygen and the formation of a Superoxidradikals or the electron gap accepts an electron of a hydroxyl ion in aqueous solution. The Hydroxylio- nen are due to the autoprotolysis of water or the basic component in sufficient quantity. Subsequently, this hydroxyl radical catalyses the H ₂ O ₂ decomposition. Now, if a basic component is present, the left side of the figure, so the formation of the hydroxyl radical is favored. The reaction with the superoxide radical O 2 is of secondary importance. If the nanoparticles are too large, recombinations of the electrons and electron-hole or gap pairs occur within the particles and thus the generation of radicals in the solution is prevented. Therefore, even larger particles, for example when using conventionally purchased finely powdered titanium dioxide, have no bleaching effect. The lifetime of radicals in basic solution is also higher than in an acidic environment. Therefore, the light basic environment is more preferable. Titanium dioxide nanoparticles are semiconductors having a bandgap energy of about 3 eV, which corresponds to an excitation wavelength of about 400 nanometers.

As already described, small particles can already cause the H ₂ O ₂ decay and the thermal excitation of a decomposition of H ₂ O ₂ . This decay can not be technically easily controlled. Apart from the chemical attack on tooth and enamel, the decay of H ₂ O would begin even before the application of the gel and the desired bleaching effect would not be sufficiently ensured. In an application according to the invention with 5% H ₂ O ₂ and anatase nanoparticles no decomposition is observed under normal conditions. On the other hand, if the gel is irradiated with UV-near light, the decay begins after a few seconds, ie the quantitative decay can be controlled by the appropriate control of the light supply or the light output and light energy. On the one hand, control is possible by optimizing the wavelength and the percentage of nanoparticles. Typically, nanoparticles of the type according to the invention (eg anatase) have a specific surface area of 70 to 120 m ² / g. The procedure runs completely without heating and therefore no thermal damage to the tooth or gums occur.

The activation of the bleaching agent can advantageously take place by means of a bleaching device 2 designed as an electric toothbrush 1, as shown in FIG. 2. This toothbrush 1 comprises a handpiece 3, which is connected via a brush tube 4 with a working head 5. Said working head 5 carries as soft structure 6 a bristle field 7, which in the illustrated embodiment has substantially a round contour and comprises a plurality of bristle tufts 8. The bristle tufts 8 mentioned are mounted on a substantially plate-shaped, in the illustrated embodiment circular bristle carrier 9, which is movably mounted on the brush tube 4 and the working head 5 connected thereto. In particular, the bristle carrier 9 can be rotatable about an axis of rotation which extends transversely to the longitudinal direction of the brush tube 4 and substantially parallel to the longitudinal direction of the bristle tufts 8.

A non-illustrated, known drive may have an electric motor in the handpiece 3, which is powered by a likewise accommodated in the handpiece 3 battery ago and on the other hand connected via a transformer, also not shown in the brush tube 4 with the bristle carrier 9, to drive this rotationally oscillating about said rotation axis 10.

As shown in FIG. 3, sitting in the working head 5 below the bristle carrier 9, that is, on the side facing away from the bristle field 7 bristle carrier 9, a light source 11 of a lighting device 12, by means of which the bristle field 9 and thus to be worn on the teeth bleach the bristle carrier 9 is irradiated therethrough with activating light. In the illustrated embodiment, the light source 11 comprises a plurality of LEDs 13 which are arranged on a common carrier plate. The said light source 11 is supplied via a supply line 14 with electrical energy. Said supply line 14 may extend in the brush tube 4 and run into the handle 3, to be connected there to the power source provided therein.

As FIG. 3 shows, the light source 11 integrated in the working head 5 irradiates the underside of the bristle carrier 9. On the one hand, light is thereby coupled into the bristle tufts 8. The bristle tufts 8 are fastened in passage openings in the bristle carrier 9, for example glued or welded therein. The light source 11 facing ends of the bristle tufts 8 serve as light entrance, while the free ends of the bristle tufts 8 serve as a light output, from which the injected light is emitted. The bristle tufts 8 themselves serve as optical fibers.

On the other hand, the bristle carrier 9 itself at least partially, in particular between the bristle tufts 8 translucent and / or light-conducting, so that from the light source 11 and the remaining between the bristle tufts 8 spaces of the bristle field 7 are illuminated with light. In this way, bleach incorporated between the bristle tufts 8 can be activated, while with the bristle field 7 the bleaching agent is rubbed on the teeth to be treated.

In order to optimize the light exposure of the bristle carrier 9 and the bristle field 7 even with limited power of the light source 11, a reflector 15 is integrated in development of the invention in the working head 5, in the illustrated embodiment on the side facing away from the bristle field 7 of the light source 11th The reflector 15 may consist of a mirrored coating on the inside, for example in the form of a coated film.

Advantageously, the bristle carrier 9 is made interchangeable with the attached bristle field 7. He can in a known manner one Have coupling portion, by means of which it is detachably fastened to the working head 5. The lighting device 12 together with the light source 11, however, remains in the working head 5, so that only the bristle field 7 is exchanged.

A further advantageous embodiment of the bleaching apparatus is shown in FIGS. 4 and 5. In this case, the bleaching device 2 comprises a hand-held part 3 in the form of a flashlight, onto which attachment part 40 designed in the form of a clip-on brush can be placed. In the illustrated embodiment, while the attachment part 40 comprises a brush tube 4, which carries a working head 5, similar to the previously shown embodiment as a soft structure 6 comprises a bristle field 7 with a plurality of bristle tufts 8, which are mounted on a plate-shaped bristle carrier 9. However, this attachment 40 can be replaced and have a different structure. It forms, so to speak, a removable part, which can be placed on the aforementioned handle 3.

As FIG. 4 shows, the handpiece 3 comprises a light source 30 which is arranged on the end side or aligned with the end face of the body of the handpiece 3 and which may advantageously be in the form of an LED arrangement which emits a light cone 31 or light beam path 31 of suitable wavelength at the end. In order to optimize the luminous efficacy, the light source 30 may be associated with an optical system, not shown in more detail, which may have, for example, a suitable reflector and / or mirror and / or be supplemented by lens optics for focusing the emitted light beams. In the handpiece 3, a power supply in the form of rechargeable batteries can furthermore be accommodated in a manner known per se for a flashlight, which feeds the abovementioned light source 30 via a control device and in particular can include a switch 32, by means of which the light source 30 is switched on and off ,

The handpiece 3 has in the region of the light source 30, a coupling portion 33 which in the illustrated embodiment as an annular groove is formed, but also in the form of other positive and / or frictional connection means, in particular quick connection means may be formed.

To the mentioned coupling portion 33 is complementary formed on the attachment part 40 provided coupling portion 41, which is formed in the illustrated embodiment as a flared connection flange, see. 4, and an end-side end portion of the brush tube 4 forms. Through the said brush tube 4, in the assembled state, the light emitted by the light source 30 is transmitted through to the working head 5 in order to be emitted in the region of the working head 5 in a defined direction 10, cf. FIG. 5. For this purpose, in the illustrated embodiment, a deflecting mirror 32 is provided in the working head 5, which guides the light 31 through the transparent bristle carrier 9 and through the bristle tufts 8. In order to avoid light losses in the brush tube 4, the inside of which may be formed in a mirrored manner, optionally with a suitable shaping of the working head 5 can be dispensed with a separate deflecting mirror 32, when the inner wall of the working head 5 is curved in a suitable manner and has a Verspiegelung that emits the light in the desired exit direction 10.

Claims

claims

A method of bleaching teeth, wherein a photoreactive and / or catalyzed bleach is applied to the teeth and activated with light, characterized in that the bleach triturated with a Borstenfeld- and / or sponge-like soft structure (6) on the toes and during rubbing is activated by light of suitable wavelength and intensity emitted on the soft structure (6).

2. Method according to the preceding claim, wherein the activation effecting light at least partially passed through the soft structure (6) and is emitted from the soft structure (6).

3. The method according to any one of the preceding claims, wherein light having a wavelength of 450 to 480 nanometers is emitted.

A method according to any one of the preceding claims, wherein the light output is less than one watt, preferably between one milliwatt per square centimeter and 25 milliwatts per square centimeter.

5. The method according to any one of the preceding claims, wherein a radical or, in particular atomic, oxygen-releasing bleaching agent is used.

6. The method according to any one of the preceding claims, wherein a bleaching agent is used with a photocatalyst formed as nanoparticles.

A method according to the preceding claim, wherein the photocatalyst is a semiconductor.

8. The method according to any one of the preceding claims, wherein nanoparticles from the group ZnO ₂ , Si, σ-Sn or TiO ₂ are used.

9. The method according to any one of the preceding claims, wherein used as anatase nanoparticles are used.

10. The method according to any one of the preceding claims, wherein the nanoparticles have a diameter of 1 nanometer to 1 micron.

11. The method according to any one of the preceding claims, wherein a bleaching agent containing hydrogen peroxide is used.

12. The method according to any one of the preceding claims, wherein the bleaching agent contains as the radical generator hydrogen peroxide.

13. The method according to the preceding claim, wherein the hydrogen peroxide is present in the form of an aqueous solution in a concentration of 1 to 10%, preferably 5%.

14. The method according to any one of the preceding claims, wherein the bleaching agent contains a thickener or a gelling agent.

15. A method according to the preceding claim, wherein the thickener is an acrylate.

16. The method according to any one of the preceding claims, wherein the bleaching agent contains an alkaline component or a buffer substance to increase the pH.

17. The method according to the preceding claim, wherein the alkaline component or buffer substance Na ₂ CO ₃ .

A process according to claim 6 or any claims appended thereto, wherein the photocatalyst is present in a concentration of about 1 to 90% by weight, preferably in a concentration of 60 to 80% by weight, based on the anhydrous bleaching agent.

19. A bleaching device for bleaching teeth according to the method of any one of the preceding claims, comprising an insertable into an oral cavity, connectable with a handle working head (5) having a borstenfeld- and / or spongy soft structure (6) for applying and rubbing a photoreactive and / or catalyzed bleaching agent on the teeth, characterized in that the working head (5) comprises illuminating means (12) for irradiating the bleaching agent with the bleach activating light on the soft structure (6 ) having.

20. Bleaching device according to the preceding claim, wherein the illumination device is integrated in the working head (5) and / or the soft structure (6) forms part of the illumination device (12).

21. Bleaching device according to one of the two preceding claims, wherein the soft structure (6) has a bristle field (7) with bristle tufts (8), wherein at least a part of the bristle tufts (8) is designed as a light guide and the illumination device (12) is arranged in that at least part of the light is fed into the bristle tufts (8) designed as light guides, forwarded therefrom and emitted at the free ends of the bristle tufts (8).

22. A bleaching device according to the preceding claim, wherein different bristle tufts (8) are formed differently light-conducting and / or in different bristle tufts (8) different intense light can be fed.

23. Bleaching device according to one of the two preceding claims, wherein bristle tufts (8) of different lengths and / or in at least one bristle tufts (8) bristles of different lengths are provided.

24. Bleaching device according to one of the preceding claims 19 to 22, wherein the soft structure (6) has light channels in the form of chimney-shaped recesses and the illumination device (12) emits light in said light channels.

25. A bleaching apparatus according to the preceding claim in conjunction with claim 21, wherein the light channels extend approximately parallel to a bristle tuft longitudinal direction and at the foot of the bristle tufts (8) light feed means are provided for feeding light into the light channels.

26. Bleaching device according to one of the preceding claims, wherein the illumination device (12) emits light in the wavelength range of 450 to 480, preferably about 460 nanometers.

27. A bleaching apparatus according to claim 21 or any of claims dependent thereon, wherein the bristle tufts (8) are fastened by fastening means free of anchor plates to a bristle carrier.

28. bleaching apparatus according to the preceding claim, wherein the bristle tufts (8) are glued to the bristle carrier (9) and / or welded.

29. A bleaching device according to claim 21 or one of the dependent claims 22 to 26, wherein the bristle tufts are each held by a seated in the walls of a bristle tuft anchor, wherein a folded around the armature portion of the respective bristle tufts means, in particular a structural change, to improve having the light coupling.

30. Bleaching device according to one of the preceding claims 19 to 29, wherein the illumination device (12) has at least one light source (11), which is arranged under a soft structure (6) bearing support plate on the working head (5).

31, bleaching device according to the preceding claim, wherein the support plate is at least partially transparent and / or light-conducting.

32. A bleaching device according to one of the two preceding claims, wherein the light source (11) comprises at least one LED (13) which is arranged in the working head (5).

33. A bleaching device according to one of the preceding claims 30 to 32, wherein the illumination device (12) has a reflector (15) which is arranged on a side remote from the soft structure (6) of the light source (11) and / or from the light source (11 ) directs emitted light onto and / or into the soft structure (6).

34. Bleaching device according to one of the preceding claims 19 to 33, wherein the illumination device (12) arranged in a handle or a brush tube (4) light source and operatively connected to the light source Lichtleitmittel and / or steering means for guiding and / or steering the light to Working head (5).

35. A bleaching device according to any one of claims 19 to 31, wherein it has a modular construction with a handpiece (3) and a detachably connectable thereto, the working head (5) comprising the attachment part (40).

36. bleaching device according to the preceding claim, wherein the hand part (3) is designed in the manner of a flashlight and / or a light source (30), in particular at least one LED, and a coupling portion (33) for preferably positive and / or frictional coupling of the Attachment (40) which is arranged in the region of the light exit from the handpiece (3) and / or the light emission from the handpiece (3).

37. A bleaching apparatus according to the preceding claim, wherein the working head (5) of the attachment (40) has a fixed light emitting surface for irradiating the bleaching agent with activating light instead of the soft structure (6), preferably said light emitting surface of a wall portion of the working head (5). is formed.

38. Bleaching device according to one of the preceding claims 35 to 37, wherein the attachment (40) Lichtleit- and / or -lenkmittel, preferably at least one mirror and / or a light guide, for forwarding the handpiece (3) received light to the working head (5 ).

39. Bleaching device according to the preceding claim, wherein the light-guiding and / or -lenkmittel are integrated in the handle and / or in the brush tube.

40. A bleaching device according to any one of the preceding claims 19 to 39, wherein the illumination device (12) comprises a power supply which is at least partially disposed in the handle.

41. Bleaching device according to one of the preceding claims 19 to 40, wherein the soft structure (6) formed exchangeable and of the illumination device (12) is detachable.

42. A bleaching apparatus according to any one of the preceding claims 19 to 41, wherein the soft structure (6) is movably mounted, wherein a drive for driving the soft structure (6) is provided.

43. A bleaching device according to any one of the preceding claims 19 to 42, wherein it is designed as a toothbrush.