PROCESS

DESCRIPTION

Technical Field

The present invention reveals a teeth whitening device with real time monitoring of whitening process. It belongs to the field of radiation therapy performed on a body parts, i.e. teeth, where whitening' (therapy) is performed by adequately selected light source acting on the active photosensitive substance used in whitening process.

Technical Problem

Generally, conventional teeth whitening procedure in the dental office may last up to two hours, and it may be painful procedure with noticeable regression.

The consumers need a customizable whitening alternative that yields results similar to the initial professional whitening with supervision, but at the convenience of the home whitening process that allows more frequent application and more stabilized whitening results. Additionally, there is a need to improve · whitening process even in dental offices to be carried out by a nurse, leaving a dentist more time for other tasks.

Having that in mind, the first technical problem solved by the present invention is to produce monitoring of teeth whitening procedure in real time in order to prevent known extreme pulpal temperature rise during the whitening process and ensures uniform whitening of the teeth.

Whitening results are best achieved when there is repeatedly use of the whitening agent such as carbamide or hydrogen peroxide, targeted to the area to be whitened, in a safe manner without high concentrations of whitening agents that can burn the gum tissue. Increasing the number of whitening processes gives the consumer ability even to perform a teeth whitening procedure at home, with unwanted side-effects greatly reduced or even eliminated.

Therefore, the second technical problem solved by the present invention is to provide easy-to-use device handling, despite a significant number of optical connections used in the equipment that have to be connected to the control unit. The intended use is oriented to professionals and non-professionals and that feature is important for reliable operation of disclosed device.

Previous State of the Art

Related art contains a large number of technical solutions directed to a teeth whitening device per se, method and control of the whitening process, agents used in whitening process etc. Intention is to mention few of them closest to the disclosed invention.

Document EP 2 386 264 A2, inventor LEVINE J.B., teaches about a mouthpiece that adjusts to the user arch sizes and seals from oxygen exposure. This document can be considered as the closest prior art. The disclosed invention consists of a flexible mouthpiece that follows the distribution of upper and lower teeth, where said teeth are positioned in the space where is possible to apply the whitening agent without being spilled into mouth cavity. The light emitters for whitening are surface mounted LED devices and furthermore, the system is equipped with the auxiliary heaters. The difference to the present invention is that it comprises real time monitoring of whitening process by taking measurement of the whitening process via charge coupling device (CCD) or similar device, and that device is further equipped with the "shut down" option in case of overheating, while the whitening process can be accelerated by using any of the known light emitters for whitening such as OLED, or UV LED. Document WO 2010/078581 Al, inventors HAMMOND T. et al., teaches about an organic light emitting diode phototherapy lighting system. The system is suitable for the phototherapy i.e. teeth whitening using the OLED technology. In contrast with the EP 2 386 264 A2 it proposes a temperature control of the process, i.e. claims 61-71, and even a thermoelectrical cooling system. However, the present invention differs from the said document having real time monitoring of whitening process by taking measurement of the whitening process via CCD or similar device.

Document US 2011/0104631 Al, inventor LEVINE J.B., teaches about methods for effecting oral treatment of teeth or gums by using whitening agents and/or light. The interesting part of the invention is using of blue to ultra-violet wavelengths for the disinfection of mouth cavity. The mentioned document is important regarding the use of high frequencies light to achieve the desired technical effects.

Document WO 2010/098761 Al, inventor LEVINE J.B., teaches about intra-oral whitening device consisting of a mouthpiece in which is embedded in a flexible circuit board and arrays of spaced apart lamps. The lamps may be light emitting diodes that generate electromagnetic radiation, preferably in the white and blue light spectrum and the infrared and ultraviolet light spectrum. The arrays are positioned to expose the facial and lingual sides of the teeth for whitening when the mouthpiece is positioned to fit upper and lower rows of teeth to be whitened within accommodating recesses.

Document US 2007/0059660 Al, inventor RIZOIU I.M., teaches about device for dental care and whitening. A dental device for exposing teeth to electromagnetic radiation includes a carrier and at least one source of electromagnetic radiation attached to the carrier and oriented so that the electromagnetic radiation is emitted from the source to a surface of a tooth. The dental device may also include a power source internally or externally disposed with respect to the carrier, and may include a circuit for controlling radiation emitted from the source. The dental device may be used for whitening teeth and dental hygiene in general.

Inspection of the documents shows that any of the above cited documents alone or in combination with each other left the essential feature of the present invention undisclosed, i.e. real time monitoring of whitening process.

Summary of the Invention

Present invention discloses a teeth whitening device with real time monitoring of whitening process that comprises a mouthpiece being inserted into a patient's mouth together with wiring and fibers interconnecting said mouthpiece with a whitening control unit. A mouthpiece is formed from anatomically shaped elastic body with plurality of bite surfaces extending out from the said body into patient' s mouth cavity preventing whitening agents to be spilled into. The deformable frame is equipped with one or more modules for whitening and measurement inserted into mouthpiece's body.

Each module consists of one or more light emitters for whitening, light emitters for monitoring, and optical fiber that is embedded into the body and which ends with a light coupling element. A light coupling element is positioned on the body surface close to a tooth surface. The body is transparent for the wavelengths emitted from light emitters for whitening and light emitters for monitoring. The control unit receives the data regarding the development of whitening process from one or more modules -and decision logic adjusts a speed of teeth whitening process in real time.

Furthermore, each module may be optionally equipped with one or more temperature sensors embedded into the mouthpiece body sending temperature information to decision logic that shuts down light emitters for whitening when whitening process exceeds the set temperature limit. The real time data of whitening process, executed by each module, comprises digital information converted from an optical signal picked by the light coupling element once the teeth are being exposed to the light emitters for monitoring. The light coupling element may be an optical lens or just the end of corresponding optical fiber. The decision logic controls and shuts down light emitters for whitening in some particular module when digital information converted from an optical signal achieves desired value for the signal picked from the said module.

The decision logic also adjusts the speed of tooth whitening process by adjusting the emitted energy of light emitters for whitening situated in each module according to the signal picked from the said module and processed by above said decision logic. The emitted energy can be regulated in simple manner via repetitively on-off process of light emitters for whitening.

The light emitters for whitening are selected from the group consisting of OLED, UV LED, blue LED or their- combination within each module. The light emitters for monitoring are selected from the group consisting of white LED, red LED, green LED, blue LED, OLED or their combination within each module.

In one aspect of the invention, the optical fiber that comes out from the module is coupled to the photodiode followed by an analog- to-digital converter for digitizing the signal intensity to be further processed by the decision logic according to the pre-stored algorithm.

In another aspect of the invention plurality of optical fibers are joined together via multi track fiber to enable quick connect fiber output to be connected and disconnected quickly from the control unit. In the said embodiment an optical signal picked by the light coupling element is converted via optical sensor selected from the group consisting of CMOS and CCD into its RGB components or alternatively into' relative intensity - to be processed by the decision logic according to the pre-stored algorithm.

Brief Description of the Figures

Figure 1 shows the device consisting of a mouthpiece, wiring and fibers and control unit. Figure 2 shows a mouthpiece with partial cross-section which reveals the position of the elements mounted on the deformable frame. Figure 3 depicts the relative position of the elements used in whitening process and in real time monitoring of whitening process. Figure 4 reveals principal scheme of disclosed device. Figures 5A-5D show independent RGB components for each whitening experiment A-D performed in vitro.

Detailed Description

New teeth whitening device with real time monitoring of whitening process is proposed as a solution of the technical problems set before. The essential parts of the device consist of mouthpiece (10), control unit (40) and wiring and fibers (20) interconnecting said mouthpiece (10) with a control unit (40) .

The technical role of the mouthpiece (10) is well described in the previous art, i.e. EP 2 386 264 A2, here depicted on Figure 1. The mouthpiece (10) is formed from anatomically shaped elastic body

(12), formed from non-toxic polymers approved for medical application by the regulating bodies, that are durable and can be shaped easily. A good example is medical grade silicone-rubber that is cured by the heat. The elastic body (12) is equipped with plurality of bite surfaces (11) extending out from the said body

(12) into patient's mouth cavity. The mutual position of bite surfaces (11), teeth and surface of elastic body (12) forms pockets. Said pockets retain whitening agent and prevent spilling the said agent into patient's mouth cavity during the treatment ensuring the optimum whitening conditions during the treatment. The elastic body

(12) wraps the deformable frame (13) caring one or more modules (30) for process of whitening and whitening process measurement. Deformable frame may be manufactured from light and rigid materials such as aluminum or aluminum alloys, or adequate plastic materials that are capable of carrying said modules (30) and retain the shape of mouthpiece (10) . Wiring and fibers (20) are inserted into elastic body (12) during the manufacturing process to provide operational energy to modules (30) and to pick the optical signals from said modules (30) as well as the temperature information.

Each module (30) consists of one or more light emitters for whitening (21), light emitters for monitoring (22), and optical fiber (24) embedded into the body (12) that ends with a light coupling element (23) positioned on the body (12) surface close to a tooth surface. In one variant of the invention, the module (30) can be equipped with one or more temperature sensors (25) embedded also into the body (12) . Figure 3 shows few modules (30) mounted on the deformable frame (13) , while Figure 2 shows an example of distribution of several module elements within the elastic body (12) .

The whitening process can be speed up or regulated by applying the light. In the present invention each module has one or more light emitters for whitening (21) selected from the group consisting of OLED, UV LED, blue LED or their combination. Preferably, light emitters for whitening (21) are distributed uniformly across the body (12) in order to maintain constant light energy flux to the whitening agent ensuring desirable whitening process performed by each module (30) . If the light emitters for whitening (21) are positioned entirely within the body (12), i.e. not close to the surface, then the used material for forming the body (12) has to be transparent for the wavelengths emitted from light emitters for whitening (21) . Clinical trials have demonstrated that the ideal source of energy should be high energy photons capable to excite the peroxide molecules without overheating the pulp of the tooth; Kugel G, Ferreira S, Sharma S, Barker ML, Gerlach RW: "Clinical trial assessing light enhancement of in-office tooth whitening", J Esthet Restor Dent 21:336-347. This is the reason why light sources are typically within the blue light spectrum as this has been found to contain the most effective wavelengths for initiating the hydrogen peroxide reaction. Good candidates for the light emitters for whitening (21) are:

1. UV LED: Model No.: YSL-RS47P4C-E3, CHINA YOUNG SUN LED TECHNOLOGY CO., LTD;

2. PLED, element described in: C. F. Qiu, L. D. Wang, H. Y. Chen, M.

Wong, and H. S. Kwok: "Room-temperature ultraviolet emission from an organic light-emitting diode", Appl . Phys . Lett. 88, 143511 (2006);

3. BLUE LED, Model No. 500TB4D Super Blue (30 Degree) 5mm LED Lamp, LightComp LED Corp.;

The regulation of the energy emitted by light emitter for whitening (21) can be performed either by the variation of the intensity, i.e. voltage regulation that distorts the emitted light spectrum, or more preferably by repeating on-off of said light emitter for whitening (21), controlled by the control unit (40).

Considering the nature of the light generation process in light emitters for whitening (21) it is known in the art that substantial amount of energy in the said emitters is dissipating in the form of heat energy. In one aspect of the invention the temperature sensors (25) are used in order to prevent an extreme pulpal temperature rise during the whitening process. The temperature sensors (25) can be of any kind such as NTC glass encapsulated thermistors distributed within the body (12) that transmit the information regarding the temperature close to some module (30) to the control unit (40) . In case of overheating of one or more modules (30) above the threshold temperature, the control unit (40) will shut down further whitening process for the said modules (30) and keep the pulpal temperature within desired values. The core of invention is real time monitoring of whitening process. In order to accomplish said task, each, module (30) embedded into the body (12) has been equipped with light emitters for monitoring (22) , and optical fiber (24) that ends with a light coupling element (23) . In order to minimize the number of wires, all light emitters for monitoring (22) although depending to various modules (30) may be optionally connected in parallel and engaged at the same time. The material used for the body (12) formation should be transparent for the wavelengths emitted from light emitters for monitoring (22) . The light emitters for monitoring (22) have to be used only during the measurement process in order to prevent overheating of the corresponding modules (30) . Once teeth being exposed by the light emitted from light emitters for monitoring (22), the reflected light is passing across the thin layer of whitening agent to be picked up by a light coupling element (23) . Light coupling elements (23) are situated at the body (12) surface, Figure 2, and are optically connected to the optical fiber (24) that guides the picked light to the measuring sensor. Good candidates for the light emitters for monitoring (22) are white LED, i.e. model No.: YSL-R547W2C-A13, CHINA YOUNG SUN LED TECHNOLOGY CO., LTD; or any other red, green or blue set of LEDs commercially available.

The light coupling element (23) should be formed as an optical lens, i.e. fish eye lens or similar considering the -fact that the technical role is only to pick the reflected light into an optical fiber (24) in course of whitening process. Instead of lens, the end of the optical fiber (24) can be also used as the light coupling element (23) with or without a drop of transparent adhesive at the surface of the body (12) that can serve as a primitive fish eye lens. The person skilled in the art can modify any light coupling element (23) to serve in the process of collecting optical signal regarding the whitening process. However, it should be noted that the light coupling element (23) has to be mounted in the manner to avoid collecting the light emitted directly from the light emitters for monitoring (22) . The optical signal picked by some optical fiber (24) pertaining to the module (30) can be processed in one or more ways. The simplest way is to use photodiode as the optical sensor (41) for converting the intensity of the reflected light into analogue electrical signal. The electrical signal is amplified and converted into digital information by an analog-to-digital converter that is processed by the (DL) decision logic (42) . Once the information received by the decision logic (42) for some module (30) achieves the desired value, the whitening process can be stopped. Also, it is possible to adjust the process to be uniformly carried for all used modules (30) by monitoring their intensity.

In another embodiment of the invention, the optical signal picked by the light coupling element (23) situated within some module (30) is converted via optical sensor (41) - OS. The OS is selected from CMOS (Complementary Metal Oxide Semiconductor) or CCD (Charge-coupled device) into desired information. It is well known in the art that CCD and CMOS image sensors are used as the _. image sensors in a digital camera; however particular use depends on the spectrum that has to be picked. Such CCD/CMOS optical sensor (41) can either convert the picked signal into the relative intensity information; or in another embodiment according to the invention - into RGB components. In both situation, i.e. intensity or RGB, this information is processed by the decision logic (42) . We used model: DCC1240C - High Sensitivity USB2.0 CMOS Camera, 1280 x 1024, Global Shutter, Color Sensor; manufacturer THORLABS Inc. in in vitro experiment described below.

Such embodiment is depicted on Figure 4; plurality of optical fibers (24) is connected to the MTF - multi track fiber (31) in order to facilitate handling with the device. Multi track fiber (31) enables the signal picked by optical fibers to be simply and reliably connected/disconnected from the optical sensor situated within the control unit (40) by using the QCFO - quick connect fiber output (32) attached to the end of a MTF and adjusted to the used optical sensor (41) . Said embodiment facilitates _^ quick an^d_ jeliabLe-handling~- even by non-technicians. Information picked from all modules (30) enables the monitoring of the whitening process as well as adjustment of the process to be uniformly carried for all used modules (30) . Suitable MTF and QCFO are possible to obtain from Newport Corporation (www.newport.com) .

The most preferred solution is one that process RGB information by the decision logic (42) , as is demonstrated by the following experiment carried out in vitro.

Figures 5A-5D show measurement carried out in vitro on specifically prepared pastilles that emulate teeth under whitening process. For better objectivity, instead of using human or bovine teeth, the research was conducted on pastilles made of hydroxylapatite powder. The pastilles were formed from hydroxylapatite for analysis, ACROS ORGANICS, Lot A0229866, US. Hydroxylapatite is naturally occurring mineral form of calcium apatite. The reason for choosing the hydroxylapatite is that up to 50% of bone by weight is a modified form of hydroxylapatite, and carbonated calcium-deficient hydroxylapatite is the ■ main mineral of which dental enamel and dentin are composed. This experimental ^" model on pastilles of hydroxilapatite was developed in our laboratory. As an overwhelming part (more than 90%) of hard dental tissue is made of hydroxylapatite and we used this compound to test whitening effects. As human or bovine teeth are quite different in their color, composition and size, assessment of pure whitening effects on real teeth is potentially subjected to large amount of confounding i.e. other factors could affect the results more than whitening procedure alone. Furthermore, the shape of real tooth is generally different and its uneven surface complicates or prevents application of more advanced and accurate methods for color change.

Each pastille is formed from exactly 400 mg hydroxylapatite and pressed and compacted under 20 bar press in the same manner to be identical. All pastilles were dried on 150°C for two hours. Each pastille was 10 mm in diameter and 2 mm thick. They were absolutely equal, had the same RGB (red, green, blue) index before dyeing in tea and there is no other parameter apart from the bleaching process that can affect the outcome, see for example Paliska, J., Stipetic, A., Tarle, Z., Ristic, M . , Ban, T., Vujicic, . , Pichler, G. (2011) "Colorimetric Assessment of Different Tooth Whitening Procedures"; Acta Stomatol Croat. (2011), 45, 258-267. The coloring of the pastilles was performed by the concentrated green tea by letting the pastilles to be exposed for a different time to the green tea solution on 29°C. Solution was made from 2 g of green tea (Cedevita®, Croatia) boiled in 100 ml of distilled water for 5 min. The similar procedure was performed in the article Sulieman . , Addy M. , Rees JS . "Development and evaluation of a method in vitro to study the effectiveness of tooth bleaching" J. Dent. (2003) 31, 415- 22) . In experiment, 25% hydrogen peroxide ZOOM2 (Discus Dental, US) was used as the whitening agent, UV LED 405 nm for · light emitters for whitening (21) and white LED for light emitters for monitoring (22) . Figures 5A-5D shows 4 different experiments performed on the pastilles being unequally treated by the green tea.

The initial conditions of the observed intensity l(t=0) of all RGB components are normalized to unity in all 4 experiments. By the course of time, the whitening process is demonstrated independently for each RGB component and is indeed measurable as the increase of the ratio I(t)/I(t=0) of each RGB component in time, where I (t) is actual intensity during the whitening procedure. It is visible from the Figures 5A-5D that 20 minutes treatment usually improves each of RGB components reflection by around 30% confirming the possibility for the process to be adequately monitored. In the present examples the measurements were performed within time interval of 5 minutes.

The pre-stored algorithm of decision logic (42) can handle received signal and correct/monitor the whitening process in different part of the mouth if necessary via switching on/off light emitters for whitening within desired modules (30) . The person skilful in the art will simply program the decision logic (42) in the form of a PLC (Programmable Logic Controller) or similar device to obtain safe and reliable operation of the teeth whitening device with real time monitoring of whitening process.

Industrial Applicability

Industrial applicability of said invention is obvious, the present invention discloses a teeth whitening device with real time monitoring of whitening process that can be used by professionals and patients equally. Furthermore, it is possible to use a slightly modified device disclosed herein, in the manner obvious for an expert in the field, in assessments and development of whitening agents and pastille models.

References

10 - mouthpiece

11 - bite surface

12 - body

13 - deformable frame

20 - wiring and fibers

21 - light emitter for whitening

22 - light emitter for monitoring

23 - light coupling element

24 - optical fiber

25 - temperature sensor

30 - module

31 - multi track fiber (MTF)

32 - quick connect fiber output (QCFO)

40 - control unit (CU)

41 - optical sensor (OS)

42 - decision logic (DL)