EP1330179A2

EP1330179A2 - Method and device for recognizing dental caries, plaque, concrements or bacterial attacks

Info

Publication number: EP1330179A2
Application number: EP02747364A
Authority: EP
Inventors: Thomas Hennig
Original assignee: Ferton Holding SA
Current assignee: Ferton Holding SA
Priority date: 2001-07-10
Filing date: 2002-06-10
Publication date: 2003-07-30
Also published as: JP2004521714A; DE10133451B4; WO2003005892A3; WO2003005892A2; US20030156788A1; DE10133451A1

Abstract

The invention relates to a method and a device for recognizing caries, plaque, concrements or bacterial attacks, wherein a radiation is generated with the aid of a light source. Said radiation is directed at a tooth to be examined and provokes a reflective radiation in said tooth. The reflective radiation is detected with a detecting device and then evaluated. The radiation is advantageously carried out with two or more spectral ranges, wherein the measured reflection intensities of the two spectral ranges are correlated as characteristic values indicating the existence of caries, plaque, concrements or bacterial attack. This can also be supported by evaluating fluorescence radiation.

Description

Method and device for the detection of caries, plaque, calculus or bacterial infection on teeth

The present invention relates to a method and a corresponding device for detecting caries, plaque, concretions, bacterial infection, etc. on teeth.

It is known to detect caries on teeth by visual examination or by using X-rays. With the help of a visual examination with white light illumination, however, it is often not possible to achieve satisfactory results because, for example, early tooth decay or hard-to-see tooth areas such as interdental spaces and gum pockets and furcations are difficult or impossible to detect. Methods previously used in dentistry do not allow a comprehensive and simple assessment of the location of concretions. The only exception here is the surgical opening of the gum pocket, since it is possible to work under direct visual control. However, this method is extremely painful for the patient to be treated. On the other hand, although X-rays have proven to be a very effective way of detecting caries or other dental diseases, this examination procedure is also not optimal due to the harmful effects of X-rays for human health, in particular early stages are not recognized. There was therefore a need to develop a new technique to determine the presence of caries and concrement on teeth.

DE 30 31 249 C2 proposed a contactless examination method for the detection of caries on human teeth, the tooth being irradiated with almost monochromatic light. The almost monochromatic light radiation stimulates fluorescence radiation on the tooth. It was discovered that the fluorescence spectrum emitted by the tooth shows clear differences between carious and healthy tooth areas. So is in the red spectral range of the fluorescence spectrum of the tooth, ie between 550 nm and 650 nm, the intensity significantly higher than in the case of a healthy tooth, based on a fluorescence signal at 450 nm. DE 30 31 249 C2 therefore proposed that the tooth be irradiated with a wavelength of 410 nm and that the fluorescence radiation of the tooth be used by means of two filters to detect a first wavelength of 450 nm and a second wavelength of 610 nm, ie in the blue and red spectral range, for example with the aid of photodetectors. The fluorescence radiation intensities detected by this arrangement are subtracted, so that a healthy tooth area can be distinguished from a carious tooth area on the basis of the difference intensity obtained thereby.

As an advantageous further development, DE 42 00 741 AI proposes that the fluorescence of the tooth be generated by excitation radiation with a wavelength in the range from 360 nm to 580 nm and that the fluorescence radiation produced on the irradiated tooth be filtered out in the wavelength range between 620 nm and 720 nm. This measure ensures that the distance between the wavelength of the excitation radiation and the received fluorescence radiation is sufficiently large that the excitation radiation cannot falsify the evaluation results by superimposing the fluorescence radiation.

A common feature of the known examination methods and devices described above is that to excite the fluorescence on a tooth to be examined, air excitation radiation with a relatively short wavelength, ie. H. smaller than 580 nm is used. On the one hand, this enables a relatively high cross section for the generation of fluorescence radiation to be achieved, especially when using wavelengths in the ultraviolet and blue spectral range, but the absolute fluorescence radiation from healthy tooth tissue in the red spectral range of the fluorescence spectrum is stronger than that of carious lesions.

In DE 195 41 686 AI it was therefore proposed to use excitation radiation with a wavelength between 600 nm and 670 nm to excite the fluorescence on a tooth to be examined. A spectral filter arrangement is used to detect the fluorescence radiation excited on the irradiated tooth. voltage used, which allows fluorescence radiation with a wavelength greater than 670 nm, ie according to DE 195 41 686 AI only fluorescence radiation with a wavelength greater than 670 nm is evaluated for the detection of caries, plaque or bacterial infection on the irradiated tooth.

The known examination methods described above, which are based on the evaluation of fluorescence radiation, have in common the problem of insufficient evaluation reliability. Either a complex direct comparison of the fluorescence beams emitted in a certain wavelength range by neighboring healthy and carious regions is necessary, which can lead to further sources of error, in particular in the case of point-by-point measurement, or the measurement signals of the fluorescence radiation recorded in two different wavelength ranges must be compared with one another in a complex manner , The methods based on fluorescence have only a low signal intensity, which makes the use of expensive detectors such as photomultipliers necessary. Due to their complicated structure, these devices cannot be produced economically and could not assert themselves on the market. If only a single spectral range is selected that is easy to detect due to the negligible background radiation of healthy tissue, a crucial disadvantage is the insufficient information that can lead to misdiagnosis if dental filler materials are within the examination range. Due to the large number of tissues and artificial materials found in the mouth, diagnostics based only on the analysis of fluorescent radiation with one or two spectral ranges is inadequate.

Starting from the known prior art described above, the present invention is based on the object of further increasing the evaluation reliability for the detection of caries, plaque, concretions or bacterial infection on teeth. In particular, misdiagnoses due to fluorescent dental filler materials should be avoided. In addition, the expenditure on equipment for the detection of pathological changes in the tooth should be simplified, and simple battery operation should be possible. According to the present invention, this object is achieved by a method having the feature of claim 1 or an apparatus having the features of claim 25. The subclaims describe preferred and advantageous embodiments of the present invention, which in turn contribute to improved sensitivity or to a construction of the device according to the invention that is as simple and compact as possible.

The invention is based on the discovery that reflection signals can be used to detect caries, plaque, concretions or bacterial infection on teeth. In the wavelength range above approximately 650 nm, the reflection of cement, that is, of healthy tooth substance, is approximately equal to the reflection of a thin layer of concrement. In the wavelength range below about 650 nm, however, the reflection of cement is greater than the reflection of a thin layer of concrement. In contrast, the reflection of a thick layer of concrement is considerably greater in the wavelength range above about 600 nm than the reflection of cement. In the wavelength range below about 500 nm, the reflection of cement is again larger than the reflection of a thick layer of concrement.

Reflection signals offer a significantly higher signal intensity than fluorescence signals, so that no complex lighting and detection systems are necessary. If the fluorescence signal is split and assessed in two different spectral ranges, the disadvantage of a low detection intensity is in at least one, namely the red spectral range. The present invention circumvents this disadvantage in that the fluorescence emission is detected over its entire spectral range or at least in a region of high signal intensity and, instead of a weaker fluorescence signal, it is related to one or two substantially stronger reflection signals.

The absolute height of the measured reflection is determined by the distance between the probe and the sample. An angle between the probe and the sample leads to a reduction in the measured reflection, preferably in the long-wave spectral range. Because reflection signals are noticeable due to the surface geometry the sample and the angle of incidence are influenced, it is advantageous to assess at least two wavelengths by reflection spectroscopy, so that standardization is achieved.

In addition, an analysis of a generated fluorescence radiation can also be evaluated in order to support the evaluation in critical areas.

The low photon yield and thus the low signal / noise ratio are the main problem with autofluorescence measurements. To achieve maximum photon yield, immersion should be used. Water or physiological saline appears suitable for in vivo measurements (N.A. in the visible spectral range, 37 ° C> 1.33). In addition to the geometric optics and the primary sensor material, the signal quality is influenced by the appropriate amplifier technology. Fluorescence excitation can take place with modulated or pulsed excitation. A lock-in amplifier is suitable for detecting modulated signals in a specific frequency and phase. All non-synchronous noise e.g. Backlight from the surgical lamp is effectively eliminated, resulting in rediscovery of signals that were buried more than 60 dB in noise.

The present invention is explained in more detail below on the basis of preferred exemplary embodiments with reference to the accompanying drawings.

1 shows a reflection spectrum of healthy tooth substance, of a thin concrement layer and of a thick concretion layer in the

Wavelength range from 400 nm to 750 nm, the tooth to be examined being irradiated with wavelengths within the entire range,

2 shows intensity profiles of the radiation returned from healthy tooth substance and from a concrement layer in the wavelength range from 350 nm to 800 nm, the tooth to be examined being irradiated with wavelengths around 370 nm and around 770 nm, 3 shows a preferred exemplary embodiment of a device according to the invention for detecting caries, plaque, concretions or bacterial infection on teeth,

4 shows a preferred exemplary embodiment of a device according to the invention for detecting caries, plaque, concretions or bacterial infection on teeth,

5 shows a preferred exemplary embodiment of a device according to the invention for detecting caries, plaque, concretions or bacterial infection on teeth,

6 shows a cross section through a preferred exemplary embodiment of a probe according to a device according to the invention,

7 shows a side view of a preferred exemplary embodiment of a probe according to the invention, and

8 shows a side view of a further preferred exemplary embodiment of a probe according to the invention.

1 shows a reflection spectrum of healthy tooth substance, of a thin stone layer and of a thick stone layer in the wavelength range from 400 nm to 750 nm. In the range above approximately 650 nm, the reflection of cement, ie of healthy tooth substance, is approximately the same the reflection of a thin layer of concrement. In the wavelength range below about 650 nm, however, the reflection of cement is greater than the reflection of a thin layer of concrement. FIG. 1 also shows that the reflection of a thick layer of concrement is already considerably greater than the reflection of cement in the wavelength range above approximately 600 nm. In the wavelength range below approximately 500 nm, the reflection of cement is again greater than the reflection of a thin layer of concrement. This discovery The invention makes use of the fact that the different reflection behavior is used as a criterion for the presence of concretion. It has been shown that the reflection signals have a significantly higher signal intensity than fluorescence signals.

According to a preferred exemplary embodiment, the tooth is exposed to radiation consisting of two wavelengths or two wavelength ranges approximately in the blue or ultraviolet light range from 320 nm to 520 nm, in particular 370 nm, and with red or near infrared light above 600 nm, in particular 770 nm, irradiated, and the reflection intensities of the same wavelength ranges are measured.

2 shows intensity profiles of the reflection signal from healthy tooth substance and from a thick concrement layer in the wavelength range from 350 nm to 800 nm, the tooth to be examined being irradiated with wavelengths in the spectral ranges around 370 nm and around 770 nm. The radiation intensities within the two wavelength ranges were chosen so that the signal level of the reflection signal from healthy cement is approximately the same in both wavelength ranges, that is to say that the radiation intensity in the near UV spectral range is approximately twice as high as the radiation intensity in NIR spectral range. In accordance with FIG. 1, concrement shows a lower reflection in the near UV spectral range and a higher reflection in the NIR spectral range in relation to healthy cement. In addition to the reflected radiation, cement shows fluorescence radiation in the blue-green spectral range with a maximum around 470 nm; a concrement layer shows almost no fluorescence.

For the evaluation, the measured reflection intensity at a wavelength of 770 nm is set in relation to the measured reflection intensity at a wavelength of 370 nm. In the case of ratio values greater than 2, the presence of concretion can be clearly affirmed. At values around 1 there is clearly cement, i.e. healthy tooth substance. In addition, the fluorescence effect can be used to confirm the result of the reflection analysis or to serve as another relevant criterion for the existence of concretion in doubtful cases. The radiation used to analyze the reflection behavior can also be used to excite the fluorescence, as in the present case. According to a preferred embodiment, the fluorescence is excited by radiation with a wavelength around 370 nm, so that overall only one irradiation with two wavelength ranges is necessary.

The absolute height of the measured reflection is determined by the distance between the probe and the sample. An angle between the probe and the sample that deviates from 0 ° leads to a reduction in the measured reflection. Since reflection signals are noticeably influenced by the surface geometry of the sample and the angle of incidence, it is also advantageous to compare reflection spectroscopy to assess at least two wavelengths. Standardization makes it possible to achieve a high level of evaluation reliability regardless of the absolute level of the measured individual signals.

The measured intensity at 770 nm thus serves as a relative reference value, so that normalization is possible. This makes a comparison with healthy neighboring tooth substance superfluous, since a certain result can already be obtained at certain points. However, the point-by-point measurement is of particular advantage if the tooth neck area is examined in tooth pockets, since it should be possible to insert a probe with the smallest possible diameter between the tooth neck and the gums in order to cut open the gums for an examination whether the area is pathological at all to avoid.

A combined detection of scattering, absorption and fluorescence takes place according to the present invention in the most signal-intensive areas: high preferential absorption in the ultraviolet range, high fluorescence signal intensity in the blue-green spectral range and almost diminished reflection in the near infrared spectral range. The use of short-wave stimulation Ambient light leads to a high cross section for the generation of fluorescence radiation in the blue-green spectral range and thus also to high signal intensity. In this area, healthy areas fluoresce much more strongly than modified tooth areas.

Simple narrow-band lighting sources, such as narrow-band LEDs can be used. The detection can also be carried out in a very simple manner by means of commercially available 3-element color sensors, which in particular have sensors for the primary colors red, green and blue, that is to say so-called RGB photodiodes. Within the three spectral ranges red, green and blue, the most informative range for evaluation can be selected by the appropriate irradiation. The three sensors for the primary colors red, green and blue are usually arranged within a circle, with each sensor being assigned a segment of a circle at 120 ° for a respective primary color.

For clear discrimination between pathologically changed tooth areas and dental filling materials, it is advantageous to use more than two wavelength ranges for the evaluation. Either two wavelength ranges can be used for the reflection analysis and one wavelength range for the fluorescence analysis, as is the case in the preferred exemplary embodiment described above, or three or more reflected wavelength ranges and / or fluorescence wavelength ranges can be used.

In the near infrared range, the absorption of radiation in biological materials is negligible. There is a so-called biological window, so that the reflected radiation is only determined by the scattering properties and not by the absorption of the examined tooth area. The radiation of healthy tooth substance reflected from the tooth surface is approximately the same in this spectral range in comparison to thin concretions (cf. FIG. 1), so that in addition to the intensity of the reflection reduced, it is reflected blue or ultraviolet radiation, the intensity of the fluorescent radiation can be normalized to this value. Due to the increased transmission of the lower-lying healthy tooth areas compared to lower-lying bacterially modified tooth areas, lower-lying layers of healthy tooth substance hardly reflected, whereas lower-lying concrement layers still make a significant contribution to the reflection signal.

3 shows a first exemplary embodiment of a device according to the invention for the detection of caries, plaque, concretions or bacterial infection on teeth. A light source 1 generates radiation 9, which is guided via a coupling lens system 2 and a feeding light guide 3 to an area 5 of a tooth 4 to be examined. The tooth 4 is irradiated with radiation 9 which, according to a preferred embodiment, consists of two separate wavelength ranges. The first wavelength range can be in the blue or ultraviolet light range from 320 nm to 520 nm, in particular around 370 nm. The second wavelength range can preferably be in the red or in the near infrared wavelength range above 600 nm, in particular above 770 nm. The radiation 9 causes a reflection radiation 10 on the tooth 4 which lies in the same wavelength ranges. In addition, fluorescence radiation of the tooth is excited, which can also be evaluated according to a preferred embodiment. The reflection radiation 10 can be fed to the detection device 8 via a light guide 6. After the detection of the measured reflection signals, the evaluation according to the invention explained above follows.

The light source 1 preferably comprises one or more light-emitting diodes, in particular narrow-band light-emitting diodes, which generate light in the wave range around approximately 370 nm or approximately 770 nm. However, one or more lasers can also be used. As shown in FIG. 4, it is possible in these embodiments to use one or more beam splitters 13 in order to pinpoint radiation from further light-emitting diodes or from further lasers into the supplying ones Coupling the light guide. It is also possible to use a light source which generates radiation with a wavelength range from approximately 320 nm to approximately 900 nm, in particular a wavelength range from white light. In this case, a spectral filter 12 can also be used in order to obtain desired wavelength ranges for the radiation 9.

The detection device 8 comprises one or more sensors, each of which has its maximum sensitivity in different wavelength ranges. It is particularly advantageous to use the three sensors to measure the intensities of the first reflected wavelength range, the second wavelength range and the fluorescence wavelength range, the sensors being adapted to these wavelength ranges. It has been shown that commercially available RGB photodiodes with three light-sensitive sensors for the primary colors red, green and blue are suitable for the device according to the invention. A spectrally selective element 7 can also be arranged in front of the detection device 8.

4 shows a further exemplary embodiment of a device according to the invention for the detection of caries, plaque, concretions or bacterial infection on teeth. In a modification of the device shown in FIG. 3, a mirror 11 is used which has a round or elliptical opening in its center. The radiation 9 is coupled into a light guide via the coupling lens system 2 through the opening of the mirror, and the reflection radiation 10 is passed on to the detection unit 8 via the mirror 11 and via a further coupling lens system 12. This ensures that only a single optical fiber can be used.

5 shows a further exemplary embodiment of a device according to the invention for detecting caries, plaque, concretions or bacterial infection on teeth. In this device, one or more outgoing light guides 6 are placed in the middle of a probe, and one or more ingoing ones Light guides 3 are arranged around the outgoing light guides 6 distributed over the circumference. This arrangement is only possible because the evaluation of reflection signals has a significantly higher signal intensity compared to fluorescence signals.

6 shows a cross section in the region of a probe according to the invention. An outgoing optical fiber 3 is arranged in the middle, whereas ten incoming optical fibers 6a are arranged around the outgoing optical fiber 3. The corresponding beam profiles are shown in FIG. 7. However, it is also possible to arrange the supply and discharge optical fibers along a line, the supply optical fibers 6a being arranged laterally on the discharge optical fibers 3. A spot measurement is achieved through these arrangements of the outgoing optical fibers, so that the measurement accuracy is further increased. Because with an enlarged measuring range, areas with healthy tooth substance and areas with concrements can be mixed at the same time and thus lead to further sources of error. In addition, the probe can be designed to be very compact, so that it is suitable for being inserted into the gum pocket between the tooth neck and the gums. This eliminates the need to cut the gums for an examination.

8 shows a further preferred exemplary embodiment of a probe according to the invention. At the end of the light guide, a coupling lens system 20 is arranged on the probe, which in this exemplary embodiment is a lens in the shape of a hemisphere. A spacer 22 is advantageously used so that the area to be examined is not shaded with the optical fibers. This spacer 22 is either hollow or solid made of quartz glass and can be provided with a reflective surface around its cylindrical circumference. A mirror surface (21) can also be provided in the tip region of the probe in order to ensure lateral deflection of the radiation. When inserting the probe into the gum pocket at approximately parallel The arrangement of the light guides to the tooth surface results in optimal radiation of the tooth surface to be examined, as well as an optimal coupling of the reflected radiation or the fluorescent radiation into the light guide leading away.

A device for supplying a liquid can also be provided on the probe tip in order to supply the probe tip with this liquid, in particular a rinsing channel with an outlet opening. On the one hand, this ensures that blood is flushed away from the probe. On the other hand, the refractive index can be influenced favorably when the radiation emerges from the probe.

Claims

claims

1. A method for recognizing caries, plaque, calculus and / or bacterial infection on teeth, comprising the steps a) irradiating a tooth (4) to be examined or an area (5) of the tooth surface to be examined with radiation (9), b) detecting radiation emanating from the tooth (4) to be examined or from the area (5) of the tooth surface to be examined, and c) evaluating the detected radiation coming from the tooth (4) to be examined or from the area to be examined ( 5) the tooth surface was reflected due to the irradiation with the radiation (9).

2. The method according to claim 1, characterized in that in step a) the tooth (4) or the area (5) of the tooth surface to be examined is irradiated with radiation which comprises one or more wavelength ranges, in particular a first one Wavelength range, a second wavelength range and / or a third or further wavelength ranges.

3. The method according to claim 1 or 2, characterized in that in step a) the tooth (4) or the area (5) of the tooth surface to be examined is irradiated with radiation which comprises a first wavelength range below of about 550 nm; especially below about 500 nm

4. The method according to any one of the preceding claims, characterized in that in step a) the tooth (4) or the area (5) of the tooth surface to be examined is irradiated with radiation which comprises a second wavelength range which is above about 600 nm, in particular above about 700 nm, in particular above about 770 nm.

5. The method according to any one of the preceding claims, characterized in that in step a) the irradiation of the tooth to be examined

(4) or the region (5) of the tooth surface to be examined is carried out with radiation which comprises a first wavelength range which lies within the spectral range between approximately 320 nm and 520 nm, in particular approximately 370 to 420 nm.

6. The method according to any one of the preceding claims, characterized in that in step c) for the evaluation of the reflected radiation, only the wavelength ranges are evaluated in which the irradiation took place in step a).

7. The method according to any one of the preceding claims, characterized in that in step c) for the evaluation of the reflected radiation (10) the corresponding intensities of the reflected wavelength ranges are related to one another as a characteristic value as to whether caries, plaque, concrements and / or bacterial infection on the tooth to be examined.

8. The method according to any one of the preceding claims, characterized by the steps of detecting and evaluating the fluorescence radiation caused on the tooth (4) by the radiation in step a), in addition to the reflection evaluation in step c), a further measurement signal for the detection of caries, plaque , Concretions and / or bacterial infestation on teeth.

9. The method according to claim 8, characterized in that a wavelength range of the radiation used in step a) serves to excite the fluorescent radiation emanating from the irradiated tooth.

10. The method according to any one of the preceding claims, characterized in that the irradiation with the respective wavelength ranges takes place simultaneously.

11. The method according to any one of the preceding claims, characterized in that the detection of the reflected radiation and / or the fluorescent radiation is carried out simultaneously.

12. The method according to any one of the preceding claims, characterized in that the irradiation with the respective wavelength ranges takes place at different times.

13. The method according to any one of the preceding claims, characterized in that the detection of the reflected radiation and / or the fluorescence radiation is carried out at different times.

14. The method according to any one of the preceding claims, characterized in that in step a) the radiation is generated with one or more light-emitting diodes, in particular narrow-band light-emitting diodes.

15. The method according to any one of the preceding claims, characterized in that in step a) the radiation is generated by one or more lasers, in particular by one or more diode lasers.

16. The method according to any one of the preceding claims, characterized in that in step a) the radiation comprises a wavelength range from about 320 nm to about 900 nm, in particular a wavelength range of white light.

17. The method according to any one of the preceding claims, characterized in that the radiation emanating from the tooth (4) to be examined or from the region (5) of the tooth surface to be examined, one or passes through several spectral filter means, in particular spectrally selective elements, interference filters, band filters or gratings.

18. The method according to any one of the preceding claims, characterized in that the radiation emanating from the tooth (4) to be examined or from the area (5) of the tooth surface to be examined, one or more prisms and / or one or more beam splitters , in particular dichroic beam splitters.

19. The method according to any one of the preceding claims, characterized in that the detection in step b) is carried out by one or more light-sensitive sensors.

20. The method according to any one of the preceding claims, characterized in that the detection in step b) is carried out by a color sensor with at least two light-sensitive sensors for measuring the intensities of the first, second and / or third reflected or emitted wavelength range.

21. The method according to any one of the preceding claims, characterized in that the detection in step b) is carried out by a spectrometer.

22. The method according to any one of the preceding claims, characterized in that the detection in step b) is carried out by a color sensor with three light-sensitive sensors for measuring the intensities of the first reflected wavelength range, the reflected second wavelength range and the fluorescence wavelength range or the reflected third Wavelength range, in particular with three light-sensitive sensors for the basic colors red, green and blue, in particular RGB photodiodes, it being possible for the signals of the light-sensitive sensors for the basic colors red, green and blue to be used for evaluating the tooth color.

23. The method according to any one of the preceding claims, characterized in that the detection in step c) is carried out by a plurality of sensors which are arranged along a line or a curve.

24. The method according to any one of the preceding claims, characterized in that the detection in step c) is carried out by a plurality of sensors which are arranged within a two-dimensional area, in particular by an image sensor, in particular by a CCD or a CMOS chip , wherein the optical fibers can be assigned to the respective sensors or pixel elements in order to obtain an image of the area to be examined.

25. Device for detecting caries, plaque, calculus and / or bacterial infection on teeth, comprising one or more light sources (1) for generating radiation (9) which is directed onto a tooth or tooth surface (4; 5) to be examined and a detection device (8) for detecting the radiation (10) which is returned, in particular reflected, by the tooth (4) to be examined or by the area (5) of the tooth surface to be examined.

26. The device according to claim 25, characterized in that the one or more light sources (1) generates radiation (9) which comprises one or more wavelength ranges, in particular a first wavelength range, a second wavelength range and / or a third wavelength range, wherein these wavelength ranges are in particular separated from one another, that is, they do not overlap spectrally.

27. The apparatus of claim 25 or 26, characterized in that the one or more light sources (1) generates radiation with one first wavelength range, which is below about 550 nm, in particular below about 500 nm.

28. Device according to one of the preceding claims, characterized in that the one or more light sources (1) emit radiation

(9) generates with a second wavelength range which is above approximately 600 nm, in particular above approximately 700 nm, in particular above approximately 770 nm.

29. Device according to one of the preceding claims, characterized in that the one or more light sources (1) generates radiation (9) within a wavelength range which is between approximately 320 nm and 520 nm, in particular between approximately 370 to 420 nm.

30. Device according to one of the preceding claims, characterized in that the detection device (8) is suitable or adapted for detecting the radiation to detect the wavelength ranges generated by the one or more light sources (1).

31. Device according to one of the preceding claims, characterized in that the detection device (8) for detecting the radiation comprises one or more sensors, each of which has its maximum sensitivity in different wavelength ranges.

32. Device according to one of the preceding claims, characterized in that the detection device (8) for detecting the radiation comprises one or more sensors which are generated approximately in or in the fluorescence wavelength ranges from the one or more light sources (1) each have their maximum sensitivity.

33. Device according to one of the preceding claims, characterized in that the device further comprises an evaluation device, in particular another processor for evaluating the reflected radiation (10), the evaluation device being suitable for relating the corresponding intensities of the reflected wavelength ranges to one another as a characteristic value as to whether caries, plaque, concrements and / or bacterial infection on tooth to be examined is present.

34. Device according to one of the preceding claims, characterized in that the detection device (8) is suitable for detecting the radiation, the reflected radiation (10) and / or the fluorescence

Detect radiation simultaneously.

35. Device according to one of the preceding claims, characterized in that the detection device (8) for detecting the strahhing is suitable for detecting the reflected radiation (10) and / or the fluorescence radiation at different times.

36. Device according to one of the preceding claims, characterized in that a device is provided in order to irradiate the tooth (4) to be examined or the area (5) of the tooth surface to be examined at different times, in particular a movable mirror arrangement, a movable prism arrangement, a filter wheel or a switching device for switching the individual light sources on and off.

37. Device according to one of the preceding claims, characterized in that one or more supplying optical fibers (3) are provided for supplying the radiation emitted by the light source (1) to the tooth or tooth surface (4; 5) to be examined, the feeding optical fiber or the feeding optical fibers (3) with or with the light sources (1) are in optical connection.

38. Device according to one of the preceding claims, characterized in that one or more laxative optical fibers (6) are provided are for removing the radiation emitted by the tooth surface to be examined (5) to the detection device (8) for detecting radiation, the dissipating optical fiber or the dissipating optical fibers (6) with the detection device (8) for detecting radiation in an optical connection stand.

39. Device according to one of the preceding claims, characterized in that one or more optical fibers (3) are provided for dissipating the radiation emitted by the tooth surface to be examined (5) to the detection device (8) for detecting radiation and for supplying the radiation emitted by the light source (1) to the tooth or tooth surface to be examined, the one or more optical fibers (3) being optically connected to the one or more light sources (1) and to the detection device (8) for detecting radiation.

40. Device according to one of the preceding claims, characterized in that between the one or more light sources (1) and the one or more optical fibers (3) a mirror (11) is arranged with a particularly elliptical opening or an unmirrored part in

Middle area, the mirror in particular has a flat, elliptical or parabolic shape.

41. Device according to one of the preceding claims, characterized in that the reflected radiation (10) via a coupling system

(12) to the detection device (8) is passed.

42. Device according to one of the preceding claims, characterized in that the one or more feeding optical fibers (3) and the one or more discharging optical fibers (5) open or end in a probe.

43. Device according to one of the preceding claims, characterized in that the one or more discharging optical fibers (6) are placed in the center of the probe, and the one or more feeding optical fibers (3) around the discharging optical fibers (6) over the circumference. are arranged distributed.

44. Device according to one of the preceding claims, characterized in that the one or more discharging optical fibers (6) are placed in the center of the probe, and the one or more feeding optical fibers (3) laterally, in particular to the right and left of the discharging optical fibers ( 6) are arranged so that the supply and discharge optical fibers are arranged in a line.

45. Device according to one of the preceding claims, characterized in that the ends of the optical fibers are chamfered in the region of the probe, in particular only in one direction.

46. Device according to one of the preceding claims, characterized in that a coupling system is arranged on the probe, in particular a lens and / or a mirror.

47. Device according to one of the preceding claims, characterized in that a spacer (22) is arranged on the probe, in particular between the coupling system (20) and the end or ends of the optical fibers.

48. Device according to one of the preceding claims, characterized in that the spacer (22) arranged on the probe is a solid or hollow cylinder which can be provided with a reflecting surface around its cylindrical circumference.

49. Device according to one of the preceding claims, characterized in that a mirror is arranged on the probe, in particular a planer, an elliptical or a parabolic mirror, the mirror being arranged in particular either at the tip of the probe or between the coupling system (20) and the end of the optical fibers.

50. Device according to one of the preceding claims, characterized in that the axis of the mirror arranged on the probe is arranged at an angle with respect to the axis of the light guide, preferably about 45 °.

51. Device according to one of the preceding claims, characterized in that a prism is arranged at the ends of the optical fibers in the region of the probe, in particular a 90 ° deflection prism with a mirrored hypotenuse.

52. Device according to one of the preceding claims, characterized in that the one or more light sources (1) are one or more light-emitting diodes, in particular narrow-band light-emitting diodes.

53. Device according to one of the preceding claims, characterized in that the one or more light sources (1) are one or more monochromatic light sources, in particular lasers and / or diode lasers, in particular in the VCSEL (Vertical Cavity Surface Emitting Laser) version. ,

54. Device according to one of the preceding claims, characterized in that one or more beam splitters are provided on the light sources in order to achieve a precise coupling into the light guide (s) by superimposing the generated radiation.

55. Device according to one of the preceding claims, characterized in that the one or more light sources (1) generate a wavelength range from approximately 320 nm to approximately 900 nm, in particular a wavelength range from white light.

56. Device according to one of the preceding claims, characterized in that one or more spectral filter means, in particular spectrally selective elements, interference filters, band filters or gratings, are arranged in front of the detection device (8) for detecting radiation.

57. Device according to one of the preceding claims, characterized in that one or more prisms and / or one or more beam splitters are arranged in front of the detection device (8) for detecting radiation.

58. Device according to one of the preceding claims, characterized in that the detection device (8) for detecting strahhing comprises one or more light-sensitive sensors.

59. Device according to one of the preceding claims, characterized in that the detection device (8) for detecting radiation comprises a color sensor with at least two light-sensitive sensors for measuring the intensities of the first, second and / or further reflected wavelength ranges.

60. Device according to one of the preceding claims, characterized in that the detection device (8) for detecting radiation comprises a color sensor with three light-sensitive sensors for

Measurement of the intensities of the first reflected wavelength range, the reflected second wavelength range and the fluorescence wavelength range or the third reflected wavelength range, the sensors being adapted to these wavelength ranges, in particular with three light-sensitive sensors for the primary colors red,

Green and blue, in particular RGB photodiodes, it being possible for the processor to be suitable for determining the tooth color based on the three light-sensitive sensors for the primary colors red, green and blue.

61. Device according to one of the preceding claims, characterized in that the detection device (8) for detecting radiation is a spectrometer, in particular a microspectrometer.

62. Device according to one of the preceding claims, characterized in that the detection device (8) for detecting radiation comprises a plurality of sensors which are arranged along a line or a curve.

63. Device according to one of the preceding claims, characterized in that the detection device (8) for detecting radiation comprises a plurality of sensors which are arranged within a two-dimensional area, in particular a CCD or CMOS chip, the optical fibers can be assigned to the respective sensors or pixel elements in order to obtain an image of the area to be examined.

64. Device according to one of the preceding claims, characterized in that the detection device (8) for detecting radiation comprises a lock-in amplifier.

65. Device according to one of the preceding claims, characterized in that the detection device (8) for detecting radiation comprises a radiation converter for shifting the wavelength range of the reflected radiation or the fluorescence radiation into a wavelength range which is better for the detection by the sensors is particularly suitable for shifting the fluorescence radiation from the blue-green wavelength range to the green wavelength range.

66. Device according to one of the preceding claims, characterized in that a device for supplying a liquid is provided. hen is to supply the probe tip with this liquid, in particular a flushing channel with an outlet opening at or in the region of the probe tip.

67. Probe for supplying radiation (9) to an area to be examined (5) and for removing radiation (10) from the area to be examined (5), consisting of one or more optical fibers (3; 6).

68. A probe according to claim 67, characterized in that the one or more optical fibers supply optical fibers (3) which are provided for supplying the radiation (9).

69. A probe according to claim 67 or 68, characterized in that the one or more optical fibers comprising optical fibers (6) are provided, which are provided for dissipating the radiation emitted by the area to be examined (10).

70. A probe according to claim 67, characterized in that the one or more optical fibers (3) is or are provided for dissipating the radiation (10) emitted by the area to be examined and for

Supplying the radiation (9).

71. A probe according to one of the preceding claims, characterized in that the one or more discharging optical fibers (6) are placed in the center of the probe, and the one or more feeding ones

Optical fibers (3) are arranged distributed around the circumference around the discharging optical fibers (6).

72. Probe according to one of the preceding claims, characterized in that the one or more optical fibers (6) which lead away are in the

Are placed in the middle, and the one or more feeding optical fibers (3) laterally, in particular on the right and left of the the optical fibers (6) are arranged so that the supply and discharge optical fibers are arranged in a line.

73. Probe according to one of the preceding claims, characterized in that the ends of the optical fibers are chamfered in the region of the probe, in particular only in one direction.

74. Probe according to one of the preceding claims, characterized in that a coupling system is arranged on the probe, in particular a lens in the shape of a hemisphere.

75. Probe according to one of the preceding claims, characterized in that a mirror is arranged on the probe, in particular a planar, an elliptical or a parabolic mirror, the mirror in particular either at the tip of the probe or between the coupling system (20 ) and the end of the optical fibers or directly on the one or more beveled surfaces of the optical fibers.

76. Probe according to one of the preceding claims, characterized in that the axis of the mirror arranged on the probe is arranged at an angle with respect to the axis of the light guide, preferably approximately 45 °.

77. Probe according to one of the preceding claims, characterized in that a prism is arranged at the ends of the optical fibers in the region of the probe, in particular before or after the coupling system (20).

78. Probe according to one of the preceding claims, characterized in that a spacer (22) is arranged on the probe, in particular between the coupling system (20) and the end or ends of the optical fibers.

79. Probe according to one of the preceding claims, characterized in that the spacer (22) arranged on the probe is a solid or hollow cylinder which can be provided with a reflecting surface around its cylindrical circumference.

80. Device according to one of the preceding claims, characterized in that a device for supplying a liquid is provided in order to supply the probe tip with this liquid, in particular a rinsing channel with an outlet opening at or in the region of the probe tip.