US20080274437A1 - Method and apparatus for identifying tooth-coloured tooth filling residues - Google Patents

Method and apparatus for identifying tooth-coloured tooth filling residues Download PDF

Info

Publication number
US20080274437A1
US20080274437A1 US12/172,322 US17232208A US2008274437A1 US 20080274437 A1 US20080274437 A1 US 20080274437A1 US 17232208 A US17232208 A US 17232208A US 2008274437 A1 US2008274437 A1 US 2008274437A1
Authority
US
United States
Prior art keywords
tooth
light
irradiation
light source
designed
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US12/172,322
Inventor
Michael Haisch
Ludwin Monz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Carl Zeiss AG
Original Assignee
Carl Zeiss AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Carl Zeiss AG filed Critical Carl Zeiss AG
Priority to US12/172,322 priority Critical patent/US20080274437A1/en
Publication of US20080274437A1 publication Critical patent/US20080274437A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61CDENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
    • A61C13/00Dental prostheses; Making same
    • A61C13/08Artificial teeth; Making same
    • A61C13/082Cosmetic aspects, e.g. inlays; Determination of the colour
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84Systems specially adapted for particular applications
    • G01N21/88Investigating the presence of flaws or contamination
    • G01N21/8803Visual inspection
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/0059Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence
    • A61B5/0082Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence adapted for particular medical purposes
    • A61B5/0088Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence adapted for particular medical purposes for oral or dental tissue
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84Systems specially adapted for particular applications
    • G01N21/88Investigating the presence of flaws or contamination
    • G01N21/8806Specially adapted optical and illumination features
    • G01N2021/8845Multiple wavelengths of illumination or detection
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84Systems specially adapted for particular applications
    • G01N21/88Investigating the presence of flaws or contamination
    • G01N21/8806Specially adapted optical and illumination features

Definitions

  • the invention concerns a method and apparatus for identifying tooth-coloured tooth filling residues.
  • DE 196 19 067 proposes distinguishing tooth filling residues from the tooth substance on the basis of the differing scatter characteristics thereof in relation to Raman scattering.
  • the free end of an optical fibre, at the other end of which there is a laser is directed on to the tooth.
  • Light scattered by the tooth substance is collected by means of a collector device and fed to an evaluation unit where it is spectrally filtered or split up. Detection of the tooth filling material is then effected in the evaluation unit on the basis of characteristic intensities.
  • the result of the detection procedure is communicated to the dentist by way of a display device or automatically registered by means of a registration device.
  • Such an apparatus requires relatively complicated and expensive analysis of the scattered light as well as a relatively high level of technical expenditure for displaying the result of the analysis procedure.
  • the object of the present invention is to provide a method of identifying tooth filling residues, by means of which the detection of tooth-coloured tooth filling residues can be simplified.
  • a further object of the invention is to provide an apparatus for carrying out the method.
  • the tooth is irradiated with light, in particular visible light.
  • the light with which the irradiation operation is effected includes at least one wavelength component which is absorbed or scattered by the tooth filling material differently from the tooth material such that the tooth filling residue differs from the tooth material in its brightness, that is to say in the intensity of the scattered light, or in its colour.
  • wavelength component denotes an individual wavelength or a wavelength range
  • colour difference denotes a spectral difference between the light scattered by the tooth material and the light which is scattered by the tooth filling material and which makes itself noticeable in the visible wavelength range.
  • the tooth filling material can be distinguished from the tooth material on the basis of differences in brightness or colour in comparison with the tooth material. Therefore the method according to the invention makes it possible to implement identification of tooth filling residues in such a way that, with the naked eye, possibly with the assistance of simple technical aids, such as for example a colour filter, the dentist can recognise the tooth filling residues. There is no need for the light scattered by the tooth to be spectrally analysed or spectrally split up, to recognise the tooth filling residues, just as there is no need for a display device for displaying the result of the analysis procedure. The technical expenditure which has to be incurred in order to recognise tooth-coloured tooth filling residues is therefore lower than in the state of the art.
  • irradiation of the tooth is effected in a locally limited region which can be given for example by a point or a line.
  • the irradiation operation can be effected both with coherent and also with incoherent light.
  • the point or the line of the light used for the irradiation operation is of a very small extent, the method can include a step of scanning the region of the tooth in which the tooth filling residues are present.
  • irradiation in line form affords the advantage that scanning needs to be effected only in one direction.
  • the first variant makes use of the fact that visible light is greatly scattered in the tooth material, in particular in the dentine, but is absorbed only to a slight degree. In contrast, in most cases the light is absorbed by the tooth filling material to a greater degree than by the tooth material. Upon local irradiation of the tooth the scattered light issues from the tooth again in the region around the illumination point so that a bright halo effect appears around the illumination point. As a filling residue generally absorbs more light than the tooth material, the filling residues in the region of the halo effect generally appear darker than the tooth material or even quite black. Therefore tooth filling materials can be easily recognised with the naked eye, possibly with the aid of a colour filter.
  • the scattering characteristics of teeth and filling material can differ greatly from one person to another or from one filling material to another. It can therefore also happen that the filling residues absorb less light than the tooth material. In those cases the method provides a result in which the tooth filling residues appear correspondingly brighter in the halo area than the tooth material.
  • the wavelength of the light can be adapted to the tooth filling material or the sensitivity of the eye in such a way that the difference in brightness between the tooth material and the tooth filling material to be identified or perception of the difference is optimised. It is particularly advantageous if the procedure uses that wavelength in which the difference in the absorption and/or scattering characteristics between the tooth material and the tooth filling material is at its greatest, as then the levels of intensity of the scattered light from the materials differ greatly. In particular red or green light has proven to be highly suitable.
  • the irradiation operation is effected with light, the spectrum of which has irregularly distributed wavelengths. That variant is based on the realisation that visible light is generally scattered greatly with a very low level of dependency on wavelength by the tooth material, in particular the dentine, but is absorbed only to a slight degree. In contrast, depending on the material involved, wavelength-dependent scattering and absorption occurs in tooth fillings. If the tooth is irradiated with light which has a spectrally irregular wavelength distribution, it is possible to recognise colour differences and/or differences in intensity between the tooth material which scatters the light independently of wavelength and the tooth filling material which scatters the light in dependence on wavelength, using the naked eye or with the aid of a filter. In particular the irregularly distributed wavelengths can be afforded by at least two wavelengths in respect of which the absorption and/or scattering capability of the tooth material differs greatly from that of the tooth filling material.
  • the wavelength distributions can also be so selected that the tooth filling material or the tooth material, in respect of at least one of those wavelengths, exhibits an extreme, that is to say a maximum or a minimum, in terms of scattering and/or absorption characteristics.
  • the maximum or minimum does not necessarily need to be an absolute maximum or minimum (maximum with the highest scattering or absorption capability of all maxima or minimum with the lowest scattering or absorption capability of all minima), but rather it is also possible to use local maxima or minima (that is to say, maxima or minima whose scattering or absorption capability does not correspond to that of the greatest maximum or minimum respectively), and that increases the number of wavelengths which can be used.
  • the distribution of the wavelengths is so selected that the blend of the wavelengths appears white. That can be embodied in particular by the spectrum having three wavelengths, for example red, green and blue, the blend of which gives white light. In that case tooth material as a wavelength-independent scattering material appears white. In contrast tooth filling residues, as generally wavelength-dependent scattering material, exhibit a colour tint, on the basis of which they can be identified.
  • the spectrum exhibits a given colour temperature.
  • the colour shade of the tooth filling material is adapted to the colour shade of the tooth in such a way that the tooth filling material is not to be distinguished from the healthy tooth either in daylight or with ambient illumination. If however the colour temperature is changed, differences between healthy tooth and tooth filling residues can be detected.
  • the light with which the irradiation operation is effected in the method according to the invention can exhibit for example a Gaussian profile in respect of its irradiation cross-section. Under some circumstances however that can mean that it is only with difficulty that it is possible to see whether differences in intensity which occur in the scattered light are to be attributed to variations in intensity in the Gaussian profile of the irradiation light or whether they are due to the difference in the scattering or absorption characteristics of tooth material and tooth filling material. In an advantageous development of the method according to the invention therefore the irradiation operation can be effected with light in respect of which the distribution of intensity in the irradiation cross-section has a constant portion in at least one direction.
  • the irradiation procedure can be effected with a light beam whose intensity distribution in the radial direction has a constant portion, for example in the form of a so-called hat top pattern.
  • a light beam whose intensity distribution in the radial direction has a constant portion, for example in the form of a so-called hat top pattern.
  • the invention also provides an apparatus for carrying out the method.
  • the irradiation device includes a light source which is distinguished in that it radiates light with at least one wavelength component which is absorbed or scattered by the tooth filling material differently from the tooth material in such a way that the tooth filling residue differs in respect of its brightness or its colour from the tooth material.
  • an adjusting device for adjusting or attenuating the intensity of the light from the light source and the irradiation device can be designed in particular for example in such a way that it illuminates the tooth in the form of a point or a line.
  • the irradiation device is such that it permits local irradiation of the tooth.
  • the light source radiates light with at least one wavelength component which is absorbed or scattered by the tooth filling material differently from the tooth material in such a way that the tooth filling residue differs from the tooth material in respect of its brightness.
  • the irradiation device can be in particular in the form of a pen which includes the light source and which is so designed that it is to be held directly against the tooth.
  • the irradiation device may also include a light guide or optical fibre which is connected to the light source and which in particular can be of such a nature that it is to be held directly against the tooth.
  • An optical means can optionally be arranged at the distal end of the light guide. In that way the light source itself can be stationary, so that less severe limits are imposed on the design configuration of the light source, than if it is to be integrated into a pen.
  • the irradiation device can be integrated into an operating microscope for observing the tooth.
  • the illumination point is displaced relative to the focal point of the operating microscope.
  • Observation of the tooth is facilitated by virtue of the fact that observation takes place in a region in which the halo is not outshone by light from the irradiation device, which is reflected by the surface of the tooth.
  • the irradiation device being so designed that illumination takes place in an annular configuration around the focal point of the operating microscope.
  • Suitable light sources are lasers and diode lasers but also incoherent light sources such as for example LEDs.
  • the light source is such that the spectrum thereof exhibits an irregular wavelength distribution, in which respect the blend of wavelengths can give in particular white light.
  • the spectrum includes at least one wavelength component which is absorbed or scattered by the tooth filling material differently from the tooth material in such a way that the tooth filling material differs from the tooth material in respect of its colour.
  • the irradiation device can include in particular three monochromatic light sources, the radiations of which exhibit different wavelengths.
  • a third configuration of the apparatus according to the invention associated with the light source is an adjusting device for adjusting the colour temperature of the light emanating from the light source.
  • the adjusting device can be used to adjust the colour temperature of the light in such a way that differences between healthy tooth and tooth filling residues are clearly apparent.
  • the light with which the irradiation operation is effected can involve, in at least one direction, a profile with a constant intensity distribution.
  • the point can have in particular an intensity distribution which has a constant portion in the radial direction.
  • a profile with an intensity distribution which has a constant portion for example a hat top profile, can have the advantage over a Gaussian profile that fewer fluctuations in intensity occur in the irradiated region of the tooth.
  • the irradiation device of the apparatus according to the invention can be integrated into an operating microscope or an OP-illumination means. It will be appreciated that it can also be in the form of an independent unit. Furthermore the apparatus according to the invention can include a scanning unit for scanning the tooth. Finally it may also have an adjusting device for adjusting the level of intensity of the light used for the irradiation procedure in order to give the user the option of adjusting an intensity which makes it easier for him to detect the tooth filling residues and which is pleasant for him.
  • FIG. 1 shows a first embodiment of the method according to the invention.
  • FIG. 2 shows a second embodiment of the method according to the invention.
  • FIG. 3 shows a first embodiment of the apparatus according to the invention for identifying tooth-coloured tooth filling residues of a tooth.
  • FIG. 4 shows a second embodiment of the apparatus according to the invention for identifying tooth-coloured tooth filling residues of a tooth.
  • FIG. 5 shows a third embodiment of the apparatus according to the invention for identifying tooth-coloured tooth filling residues of a tooth.
  • FIG. 6 shows a fourth embodiment of the apparatus according to the invention for identifying tooth-coloured tooth filling residues of a tooth.
  • FIG. 7 shows a fifth embodiment of the apparatus according to the invention for identifying tooth-coloured tooth filling residues of a tooth.
  • FIG. 8 shows a possible intensity profile of a light beam used in the invention in the radial direction.
  • FIG. 9 shows an alternative configuration of the embodiment shown in FIG. 1 .
  • FIG. 1 A first embodiment of the method according to the invention is described hereinafter with reference to FIG. 1 .
  • the light beam 5 involves the hat top profile illustrated in FIG. 8 as its intensity profile and is preferably formed from coloured and in particular monochromatic light.
  • the wavelength or wavelengths of the light beam 5 is or are so selected that the light is strongly scattered by the tooth material, in particular the dentine, but is greatly absorbed by the tooth filling material. In the present embodiment red or green light is used.
  • the light scattered by the tooth material then issues inter alia around the irradiated region, as is indicated by the arrows 7 in FIG. 1 .
  • the tooth filling material 3 absorbs the light used for irradiation purposes more greatly than the tooth material 1 . It should be pointed out however that this is not a prerequisite for proper operation of the method according to the invention. The only important consideration is that the absorption and/or scattering characteristics of tooth filling material 3 and tooth material 1 differ for the light selected for the irradiation procedure and that this difference is perceptible in terms of a difference in brightness or colour in the light scattered by the tooth filling material 3 and the tooth material 1 respectively.
  • the tooth filling material 3 can also absorb the light selected for the irradiation procedure to a lesser degree than the tooth material. In that case the tooth filling material 3 would appear brighter than the tooth material 1 .
  • a corresponding consideration also applies in regard to the embodiments described hereinafter.
  • irradiation of the tooth 1 is not effected in the form of a point but in the form of a line as is shown in FIG. 9 .
  • the intensity profile of the light perpendicularly to the direction in which it extends, preferably has a constant portion, for example in the form of a very narrow hat top profile. In the regions on both sides of the irradiation line 6 , it is possible to distinguish between the tooth material 1 and the tooth filling material 3 , on the basis of the intensity of the scattered light.
  • the dentist can ascertain the extent of the tooth filling or tooth filling residues by scanning the tooth 1 perpendicularly to the direction in which the irradiation line 6 extends.
  • FIG. 2 shows a second embodiment of the method according to the invention.
  • the tooth is irradiated with light 5 ′ over a large area.
  • the light used for the irradiation procedure involves a spectrum with irregularly distributed wavelengths and is preferably of an intensity which is substantially constant over the entire irradiation cross-section. It appears white however in the blend of the wavelengths.
  • the spectrum includes red, green and blue light, as is indicated in FIG. 2 by dotted, solid and broken lines respectively.
  • the light 5 ′ is scattered by the tooth material and a part of the scattered light 7 issues from the tooth 1 again.
  • the tooth material in particular the dentine, scatters visible light only with a very low level of wavelength dependency, the scattered light 7 appears substantially white like the light 5 ′ with which the tooth 1 is irradiated.
  • the tooth filling material In contrast to the tooth material however the tooth filling material involves wavelength-dependent scattering and absorption characteristics. In the region of a tooth filling residue 3 therefore the scattered light involves a coloured tint, on the basis of which the tooth filling residue 3 can be easily identified.
  • the wavelengths of the spectrum of the light used for the irradiation procedure are preferably so selected that they are scattered to greatly different degrees by the tooth filling material.
  • the present embodiment uses a mixture of red, green and blue light for irradiating the tooth, but it is sufficient if at least two different wavelengths are used. Admittedly, the tooth then no longer appears white but it is still possible to establish a colour difference between the tooth material and the tooth filling material, in particular when the wavelengths used are adapted to the scattering or absorption capability of the tooth material and/or the tooth filling material.
  • irradiation of the tooth 1 can also be effected with light whose colour temperature is variable.
  • the colour shade of the tooth filling material is matched to the tooth in such a way that the tooth filling cannot be distinguished from the tooth material either in daylight or under ambient lighting.
  • the colour temperature for example of light whose colour temperature corresponds to daylight, in relation to light whose colour temperature corresponds to ambient lighting, it is possible to detect differences between tooth material and tooth filling material, which are due to the wavelength-dependent scattering and absorption characteristics of the tooth filling material. If the scattering and absorption characteristics of the tooth filling material are already known in advance, the colour temperature of the light used for the irradiation procedure can be adapted from the outset to the tooth filling material in such a way that the differences which occur between the tooth material and the tooth filling material are easy to recognise.
  • FIGS. 3 to 7 show various embodiments of the apparatus according to the invention for identifying tooth-coloured tooth filling residues of a tooth.
  • FIG. 3 shows a first embodiment of the apparatus according to the invention. This embodiment is suitable for carrying out the method in accordance with the first embodiment of the method of the invention.
  • the Figure shows the tooth 1 and the scattered light 7 .
  • the apparatus has an irradiation device which is in the form of a pen 11 .
  • the irradiation device also has an intensity regulator (not shown).
  • the pen 11 includes a light source 12 which produces for example red or green light and can be held directly against the tooth 1 for local irradiation thereof. It produces a light point, the radial intensity distribution of which corresponds to the hat top profile shown in FIG. 8 .
  • the light source 12 is supplied with power by way of a line 13 but alternatively it can also be supplied with power by means of an energy storage means integrated into the pen 11 , such as for example a battery or an accumulator.
  • Coherent light sources such as for example lasers or diode lasers but also incoherent light sources such as for example LEDs can be used as the light sources 12 .
  • FIG. 4 shows a second embodiment of the apparatus according to the invention. This embodiment is also suitable for carrying out the method in accordance with the first embodiment of the method of the invention.
  • the embodiment shown in FIG. 4 differs from the embodiment illustrated in FIG. 3 in that the irradiation device, instead of a pen 11 with an integrated light source 12 , includes a stationary light source 22 and a light guide or optical fibre 21 .
  • the light guide 21 can be held against the tooth so that the tooth can be irradiated locally with the light of the light source 22 by means of the light guide 11 .
  • FIG. 5 shows a third embodiment of the apparatus according to the invention. This embodiment is also suitable for carrying out the method in accordance with the first embodiment of the method of the invention.
  • the Figure also shows an operating microscope 30 , into which an irradiation unit 31 and 32 is integrated.
  • the irradiation unit includes a light source 32 which produces for example red or green light as well as an optical focusing means 31 , by way of which irradiation of the tooth 1 can be locally limited.
  • the optical focusing means 31 can be of such a configuration that the light from the light source 32 is focused on to a point which is slightly displaced relative to the focal point of the microscope 30 . In the simplest case a single focusing lens can then serve as the optical focusing means 31 .
  • the optical focusing means 31 can also be designed in such a way that irradiation of the tooth 1 is effected in an annular configuration around the focal point of the microscope 30 . Fluctuations in brightness in the coloured halo, which are not to be attributed to tooth filling residues, are reduced by the annular illumination effect.
  • irradiation can be effected in the form of a line, as is illustrated in FIG. 9 .
  • the irradiation device additionally includes a scanning device in order to be able to scan the tooth with the line.
  • a scanning device can however also be provided when illumination in point form or circle form is involved, in particular if the point or circle cross-section is very small or the region of the tooth to be investigated is large.
  • Examination of the tooth 1 for tooth filling residues is effected with the operating microscope 30 . It will be appreciated that the examination procedure can also be effected by means of an operating microscope when the irradiation unit is not integrated into the operating microscope but is in the form of an independent unit.
  • FIG. 6 shows a fourth embodiment of the apparatus according to the invention. This embodiment is designed for carrying out the method in accordance with the second embodiment of the method of the invention.
  • an irradiation apparatus 40 which includes a light source unit 42 for producing white light and an optical irradiation means 41 for irradiating the tooth with the white light.
  • the light source unit includes three light sources 43 a , 43 b , 43 c for producing red, green and blue light.
  • lasers or LEDs can be used as the light sources 43 a , 43 b , 43 c .
  • the light sources 43 a , 43 b , 43 c are connected by way of light guides 44 a , 44 b , 44 c to a mixer 45 in which the light is mixed in such a way that the mixed light appears white.
  • the mixer 45 is connected to an optical irradiation means 41 by way of a further light guide 46 .
  • the optical irradiation means 41 is of such a configuration that the tooth can be irradiated with the mixed light, in particular over a large area and uniformly.
  • the optical irradiation means 41 is for example of such a design configuration that the beam cross-section in the radial direction involves the hat top profile shown in FIG. 8 .
  • FIG. 7 A fifth embodiment of the apparatus according to the invention is shown in FIG. 7 .
  • the apparatus 50 includes a light source 52 and an optical irradiation means 51 , by means of which the tooth can be irradiated with the light from the light source in particular over a large area and uniformly. It is also advantageous in this embodiment if the beam cross-section involves a constant intensity distribution.
  • the light source 52 is of such a nature that its colour temperature can be varied by means of an adjusting device 53 connected to the light source.
  • the colour temperature can be varied by means of the adjusting device until a colour temperature is set, at which the tooth filling material differs from the tooth material. If the scattering or absorption characteristics of the tooth filling material are known, the colour temperature can also be already set prior to the irradiation procedure, in such a way that the tooth filling material can be recognised. In that case there is no need to search for the correct adjustment.
  • All the described embodiments can have an adjustment option for adjusting the intensity of the light used for the irradiation procedure in order to give the user the option of adjusting the intensity to a value which is pleasant for him and which guarantees an optimum distinction between tooth material and tooth filling material.

Abstract

A tooth is irradiated with light (5), in particular with visible light for identifying tooth-coloured tooth filling residues (3) of the tooth. The light with which the irradiation procedure is effected includes at least one wavelength component that is absorbed or scattered by the tooth filling material differently from the tooth material in such a way that the tooth filling material differs from the tooth material in respect of its brightness or in respect of its colour. Thus the identification of tooth filling residues (3) can be effected in such a way that the dentist can recognise the tooth filling residues (3) with the naked eye, or possibly with the assistance of simple technical aids such as for example a colour filter.

Description

  • This application is a continuation of U.S. patent application Ser. No. 10/892,019, filed on Jul. 15, 2004.
  • BACKGROUND OF THE INVENTION
  • 1. Field of the Invention
  • The invention concerns a method and apparatus for identifying tooth-coloured tooth filling residues.
  • 2. Description of the Related Art
  • For some time now tooth fillings have been used in dental medicine, which can no longer be readily distinguished from healthy tooth. If those fillings have to be removed it is difficult for the dentist to see whether the filling has been completely removed.
  • Therefore technical aids have been proposed for discovering tooth filling residues. DE 196 19 067 proposes distinguishing tooth filling residues from the tooth substance on the basis of the differing scatter characteristics thereof in relation to Raman scattering. To find tooth filling residues, the free end of an optical fibre, at the other end of which there is a laser, is directed on to the tooth. Light scattered by the tooth substance is collected by means of a collector device and fed to an evaluation unit where it is spectrally filtered or split up. Detection of the tooth filling material is then effected in the evaluation unit on the basis of characteristic intensities. The result of the detection procedure is communicated to the dentist by way of a display device or automatically registered by means of a registration device. However such an apparatus requires relatively complicated and expensive analysis of the scattered light as well as a relatively high level of technical expenditure for displaying the result of the analysis procedure.
  • Therefore the object of the present invention is to provide a method of identifying tooth filling residues, by means of which the detection of tooth-coloured tooth filling residues can be simplified. A further object of the invention is to provide an apparatus for carrying out the method.
  • SUMMARY OF THE INVENTION
  • In the method of the invention for identifying tooth-coloured tooth filling residues of a tooth, the tooth is irradiated with light, in particular visible light. In that connection, the light with which the irradiation operation is effected includes at least one wavelength component which is absorbed or scattered by the tooth filling material differently from the tooth material such that the tooth filling residue differs from the tooth material in its brightness, that is to say in the intensity of the scattered light, or in its colour. In that respect the term wavelength component denotes an individual wavelength or a wavelength range and the term colour difference denotes a spectral difference between the light scattered by the tooth material and the light which is scattered by the tooth filling material and which makes itself noticeable in the visible wavelength range.
  • By virtue of the differing absorption or scatter of at least one wavelength component, the tooth filling material can be distinguished from the tooth material on the basis of differences in brightness or colour in comparison with the tooth material. Therefore the method according to the invention makes it possible to implement identification of tooth filling residues in such a way that, with the naked eye, possibly with the assistance of simple technical aids, such as for example a colour filter, the dentist can recognise the tooth filling residues. There is no need for the light scattered by the tooth to be spectrally analysed or spectrally split up, to recognise the tooth filling residues, just as there is no need for a display device for displaying the result of the analysis procedure. The technical expenditure which has to be incurred in order to recognise tooth-coloured tooth filling residues is therefore lower than in the state of the art.
  • In a first variant of the method according to the invention irradiation of the tooth is effected in a locally limited region which can be given for example by a point or a line. In that case the irradiation operation can be effected both with coherent and also with incoherent light. If the point or the line of the light used for the irradiation operation is of a very small extent, the method can include a step of scanning the region of the tooth in which the tooth filling residues are present. In that respect irradiation in line form affords the advantage that scanning needs to be effected only in one direction.
  • The first variant makes use of the fact that visible light is greatly scattered in the tooth material, in particular in the dentine, but is absorbed only to a slight degree. In contrast, in most cases the light is absorbed by the tooth filling material to a greater degree than by the tooth material. Upon local irradiation of the tooth the scattered light issues from the tooth again in the region around the illumination point so that a bright halo effect appears around the illumination point. As a filling residue generally absorbs more light than the tooth material, the filling residues in the region of the halo effect generally appear darker than the tooth material or even quite black. Therefore tooth filling materials can be easily recognised with the naked eye, possibly with the aid of a colour filter. It should be noted however that the scattering characteristics of teeth and filling material can differ greatly from one person to another or from one filling material to another. It can therefore also happen that the filling residues absorb less light than the tooth material. In those cases the method provides a result in which the tooth filling residues appear correspondingly brighter in the halo area than the tooth material.
  • If the irradiation operation is effected with coloured, in particular monochromatic, light, the wavelength of the light can be adapted to the tooth filling material or the sensitivity of the eye in such a way that the difference in brightness between the tooth material and the tooth filling material to be identified or perception of the difference is optimised. It is particularly advantageous if the procedure uses that wavelength in which the difference in the absorption and/or scattering characteristics between the tooth material and the tooth filling material is at its greatest, as then the levels of intensity of the scattered light from the materials differ greatly. In particular red or green light has proven to be highly suitable.
  • In a second variant of the method according to the invention the irradiation operation is effected with light, the spectrum of which has irregularly distributed wavelengths. That variant is based on the realisation that visible light is generally scattered greatly with a very low level of dependency on wavelength by the tooth material, in particular the dentine, but is absorbed only to a slight degree. In contrast, depending on the material involved, wavelength-dependent scattering and absorption occurs in tooth fillings. If the tooth is irradiated with light which has a spectrally irregular wavelength distribution, it is possible to recognise colour differences and/or differences in intensity between the tooth material which scatters the light independently of wavelength and the tooth filling material which scatters the light in dependence on wavelength, using the naked eye or with the aid of a filter. In particular the irregularly distributed wavelengths can be afforded by at least two wavelengths in respect of which the absorption and/or scattering capability of the tooth material differs greatly from that of the tooth filling material.
  • The wavelength distributions can also be so selected that the tooth filling material or the tooth material, in respect of at least one of those wavelengths, exhibits an extreme, that is to say a maximum or a minimum, in terms of scattering and/or absorption characteristics. In that respect the maximum or minimum does not necessarily need to be an absolute maximum or minimum (maximum with the highest scattering or absorption capability of all maxima or minimum with the lowest scattering or absorption capability of all minima), but rather it is also possible to use local maxima or minima (that is to say, maxima or minima whose scattering or absorption capability does not correspond to that of the greatest maximum or minimum respectively), and that increases the number of wavelengths which can be used. In that respect, in particular also economic aspects may be significant in terms of the choice of the wavelengths used. Thus light sources for different wavelengths involve for example different costs. Therefore, when choosing the wavelengths, it is possible to weigh up between suitability for use in the method and the economy aspect, for example a maximum with a scattering or absorption capability which is not quite so high can be selected if the corresponding light source is markedly cheaper than that for the wavelength of a different maximum.
  • In a configuration of the second variant the distribution of the wavelengths is so selected that the blend of the wavelengths appears white. That can be embodied in particular by the spectrum having three wavelengths, for example red, green and blue, the blend of which gives white light. In that case tooth material as a wavelength-independent scattering material appears white. In contrast tooth filling residues, as generally wavelength-dependent scattering material, exhibit a colour tint, on the basis of which they can be identified.
  • In an alternative configuration of the second variant wavelength distribution in the spectrum is so selected that the spectrum exhibits a given colour temperature. Usually the colour shade of the tooth filling material is adapted to the colour shade of the tooth in such a way that the tooth filling material is not to be distinguished from the healthy tooth either in daylight or with ambient illumination. If however the colour temperature is changed, differences between healthy tooth and tooth filling residues can be detected.
  • The light with which the irradiation operation is effected in the method according to the invention can exhibit for example a Gaussian profile in respect of its irradiation cross-section. Under some circumstances however that can mean that it is only with difficulty that it is possible to see whether differences in intensity which occur in the scattered light are to be attributed to variations in intensity in the Gaussian profile of the irradiation light or whether they are due to the difference in the scattering or absorption characteristics of tooth material and tooth filling material. In an advantageous development of the method according to the invention therefore the irradiation operation can be effected with light in respect of which the distribution of intensity in the irradiation cross-section has a constant portion in at least one direction. In particular the irradiation procedure can be effected with a light beam whose intensity distribution in the radial direction has a constant portion, for example in the form of a so-called hat top pattern. With that configuration, the above-indicated problems do not occur or occur only to a slight degree as the irradiated regions are irradiated substantially with light of the same intensity.
  • Besides the method of identifying tooth-coloured tooth filling residues the invention also provides an apparatus for carrying out the method.
  • An apparatus according to the invention for identifying tooth-coloured tooth filling residues of a tooth includes an irradiation device for irradiating the tooth with light. The irradiation device includes a light source which is distinguished in that it radiates light with at least one wavelength component which is absorbed or scattered by the tooth filling material differently from the tooth material in such a way that the tooth filling residue differs in respect of its brightness or its colour from the tooth material. In addition there may be an adjusting device for adjusting or attenuating the intensity of the light from the light source and the irradiation device can be designed in particular for example in such a way that it illuminates the tooth in the form of a point or a line.
  • In a first configuration of the apparatus the irradiation device is such that it permits local irradiation of the tooth. In addition the light source radiates light with at least one wavelength component which is absorbed or scattered by the tooth filling material differently from the tooth material in such a way that the tooth filling residue differs from the tooth material in respect of its brightness.
  • The irradiation device can be in particular in the form of a pen which includes the light source and which is so designed that it is to be held directly against the tooth.
  • Alternatively the irradiation device may also include a light guide or optical fibre which is connected to the light source and which in particular can be of such a nature that it is to be held directly against the tooth. An optical means can optionally be arranged at the distal end of the light guide. In that way the light source itself can be stationary, so that less severe limits are imposed on the design configuration of the light source, than if it is to be integrated into a pen.
  • In a further configuration the irradiation device can be integrated into an operating microscope for observing the tooth. In particular it can be so designed that the illumination point is displaced relative to the focal point of the operating microscope. Observation of the tooth is facilitated by virtue of the fact that observation takes place in a region in which the halo is not outshone by light from the irradiation device, which is reflected by the surface of the tooth. Alternatively, that can also be achieved by the irradiation device being so designed that illumination takes place in an annular configuration around the focal point of the operating microscope.
  • Suitable light sources are lasers and diode lasers but also incoherent light sources such as for example LEDs.
  • In a second configuration of the apparatus according to the invention the light source is such that the spectrum thereof exhibits an irregular wavelength distribution, in which respect the blend of wavelengths can give in particular white light. The spectrum includes at least one wavelength component which is absorbed or scattered by the tooth filling material differently from the tooth material in such a way that the tooth filling material differs from the tooth material in respect of its colour. The irradiation device can include in particular three monochromatic light sources, the radiations of which exhibit different wavelengths.
  • In a third configuration of the apparatus according to the invention associated with the light source is an adjusting device for adjusting the colour temperature of the light emanating from the light source. The adjusting device can be used to adjust the colour temperature of the light in such a way that differences between healthy tooth and tooth filling residues are clearly apparent.
  • In the apparatus according to the invention the light with which the irradiation operation is effected can involve, in at least one direction, a profile with a constant intensity distribution. If the irradiation device is so designed that it illuminates the tooth in point form, the point can have in particular an intensity distribution which has a constant portion in the radial direction. As stated above, a profile with an intensity distribution which has a constant portion, for example a hat top profile, can have the advantage over a Gaussian profile that fewer fluctuations in intensity occur in the irradiated region of the tooth.
  • In addition the irradiation device of the apparatus according to the invention can be integrated into an operating microscope or an OP-illumination means. It will be appreciated that it can also be in the form of an independent unit. Furthermore the apparatus according to the invention can include a scanning unit for scanning the tooth. Finally it may also have an adjusting device for adjusting the level of intensity of the light used for the irradiation procedure in order to give the user the option of adjusting an intensity which makes it easier for him to detect the tooth filling residues and which is pleasant for him.
  • Further features, properties and advantages of the invention are described hereinafter by means of embodiments with reference to the accompanying Figures.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. 1 shows a first embodiment of the method according to the invention.
  • FIG. 2 shows a second embodiment of the method according to the invention.
  • FIG. 3 shows a first embodiment of the apparatus according to the invention for identifying tooth-coloured tooth filling residues of a tooth.
  • FIG. 4 shows a second embodiment of the apparatus according to the invention for identifying tooth-coloured tooth filling residues of a tooth.
  • FIG. 5 shows a third embodiment of the apparatus according to the invention for identifying tooth-coloured tooth filling residues of a tooth.
  • FIG. 6 shows a fourth embodiment of the apparatus according to the invention for identifying tooth-coloured tooth filling residues of a tooth.
  • FIG. 7 shows a fifth embodiment of the apparatus according to the invention for identifying tooth-coloured tooth filling residues of a tooth.
  • FIG. 8 shows a possible intensity profile of a light beam used in the invention in the radial direction.
  • FIG. 9 shows an alternative configuration of the embodiment shown in FIG. 1.
  • DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
  • A first embodiment of the method according to the invention is described hereinafter with reference to FIG. 1.
  • Referring to FIG. 1 illustrated therein are a tooth 1, a tooth filling residue 3 and a light beam 5 with which the tooth 1 is irradiated in a locally limited region. In the radial direction the light beam 5 involves the hat top profile illustrated in FIG. 8 as its intensity profile and is preferably formed from coloured and in particular monochromatic light. The wavelength or wavelengths of the light beam 5 is or are so selected that the light is strongly scattered by the tooth material, in particular the dentine, but is greatly absorbed by the tooth filling material. In the present embodiment red or green light is used. The light scattered by the tooth material then issues inter alia around the irradiated region, as is indicated by the arrows 7 in FIG. 1. Therefore a coloured halo appears around the illumination point. The scattered light is however absorbed by the tooth filling material more greatly than by the tooth material so that less scattered light issues from the tooth at the location of the tooth filling residue 3, whereby the tooth filling residue 3 appears darker than the tooth material surrounding it. In the extreme case the tooth filling residue 3 can even appear entirely black.
  • It has been assumed in the described embodiment that the tooth filling material 3 absorbs the light used for irradiation purposes more greatly than the tooth material 1. It should be pointed out however that this is not a prerequisite for proper operation of the method according to the invention. The only important consideration is that the absorption and/or scattering characteristics of tooth filling material 3 and tooth material 1 differ for the light selected for the irradiation procedure and that this difference is perceptible in terms of a difference in brightness or colour in the light scattered by the tooth filling material 3 and the tooth material 1 respectively. For example, depending on the material used and the individual absorption characteristics of the teeth, the tooth filling material 3 can also absorb the light selected for the irradiation procedure to a lesser degree than the tooth material. In that case the tooth filling material 3 would appear brighter than the tooth material 1. A corresponding consideration also applies in regard to the embodiments described hereinafter.
  • In an alternative configuration of the first embodiment irradiation of the tooth 1 is not effected in the form of a point but in the form of a line as is shown in FIG. 9. The intensity profile of the light, perpendicularly to the direction in which it extends, preferably has a constant portion, for example in the form of a very narrow hat top profile. In the regions on both sides of the irradiation line 6, it is possible to distinguish between the tooth material 1 and the tooth filling material 3, on the basis of the intensity of the scattered light. By virtue of the greater absorption of the light in the tooth filling material 3 the regions on both sides of the irradiation line 6, where the tooth material 1 is disposed, appear brighter than where the tooth filling material 3 is to be found. The dentist can ascertain the extent of the tooth filling or tooth filling residues by scanning the tooth 1 perpendicularly to the direction in which the irradiation line 6 extends.
  • FIG. 2 shows a second embodiment of the method according to the invention. In this embodiment the tooth is irradiated with light 5′ over a large area. The light used for the irradiation procedure involves a spectrum with irregularly distributed wavelengths and is preferably of an intensity which is substantially constant over the entire irradiation cross-section. It appears white however in the blend of the wavelengths. In the illustrated embodiment the spectrum includes red, green and blue light, as is indicated in FIG. 2 by dotted, solid and broken lines respectively. The light 5′ is scattered by the tooth material and a part of the scattered light 7 issues from the tooth 1 again. As the tooth material, in particular the dentine, scatters visible light only with a very low level of wavelength dependency, the scattered light 7 appears substantially white like the light 5′ with which the tooth 1 is irradiated.
  • In contrast to the tooth material however the tooth filling material involves wavelength-dependent scattering and absorption characteristics. In the region of a tooth filling residue 3 therefore the scattered light involves a coloured tint, on the basis of which the tooth filling residue 3 can be easily identified.
  • The wavelengths of the spectrum of the light used for the irradiation procedure are preferably so selected that they are scattered to greatly different degrees by the tooth filling material.
  • Admittedly, the present embodiment uses a mixture of red, green and blue light for irradiating the tooth, but it is sufficient if at least two different wavelengths are used. Admittedly, the tooth then no longer appears white but it is still possible to establish a colour difference between the tooth material and the tooth filling material, in particular when the wavelengths used are adapted to the scattering or absorption capability of the tooth material and/or the tooth filling material.
  • In a modification of the second embodiment irradiation of the tooth 1 can also be effected with light whose colour temperature is variable.
  • Usually the colour shade of the tooth filling material is matched to the tooth in such a way that the tooth filling cannot be distinguished from the tooth material either in daylight or under ambient lighting. On the basis of a variation in the colour temperature, for example of light whose colour temperature corresponds to daylight, in relation to light whose colour temperature corresponds to ambient lighting, it is possible to detect differences between tooth material and tooth filling material, which are due to the wavelength-dependent scattering and absorption characteristics of the tooth filling material. If the scattering and absorption characteristics of the tooth filling material are already known in advance, the colour temperature of the light used for the irradiation procedure can be adapted from the outset to the tooth filling material in such a way that the differences which occur between the tooth material and the tooth filling material are easy to recognise.
  • FIGS. 3 to 7 show various embodiments of the apparatus according to the invention for identifying tooth-coloured tooth filling residues of a tooth.
  • FIG. 3 shows a first embodiment of the apparatus according to the invention. This embodiment is suitable for carrying out the method in accordance with the first embodiment of the method of the invention.
  • The Figure shows the tooth 1 and the scattered light 7. For local irradiation of the tooth 1 the apparatus has an irradiation device which is in the form of a pen 11. To adjust the intensity of radiation the irradiation device also has an intensity regulator (not shown).
  • The pen 11 includes a light source 12 which produces for example red or green light and can be held directly against the tooth 1 for local irradiation thereof. It produces a light point, the radial intensity distribution of which corresponds to the hat top profile shown in FIG. 8. The light source 12 is supplied with power by way of a line 13 but alternatively it can also be supplied with power by means of an energy storage means integrated into the pen 11, such as for example a battery or an accumulator.
  • Coherent light sources such as for example lasers or diode lasers but also incoherent light sources such as for example LEDs can be used as the light sources 12.
  • FIG. 4 shows a second embodiment of the apparatus according to the invention. This embodiment is also suitable for carrying out the method in accordance with the first embodiment of the method of the invention.
  • The embodiment shown in FIG. 4 differs from the embodiment illustrated in FIG. 3 in that the irradiation device, instead of a pen 11 with an integrated light source 12, includes a stationary light source 22 and a light guide or optical fibre 21. The light guide 21 can be held against the tooth so that the tooth can be irradiated locally with the light of the light source 22 by means of the light guide 11.
  • FIG. 5 shows a third embodiment of the apparatus according to the invention. This embodiment is also suitable for carrying out the method in accordance with the first embodiment of the method of the invention.
  • Besides the tooth 1 and the scattered light 7 the Figure also shows an operating microscope 30, into which an irradiation unit 31 and 32 is integrated. The irradiation unit includes a light source 32 which produces for example red or green light as well as an optical focusing means 31, by way of which irradiation of the tooth 1 can be locally limited. The optical focusing means 31 can be of such a configuration that the light from the light source 32 is focused on to a point which is slightly displaced relative to the focal point of the microscope 30. In the simplest case a single focusing lens can then serve as the optical focusing means 31. Alternatively the optical focusing means 31 can also be designed in such a way that irradiation of the tooth 1 is effected in an annular configuration around the focal point of the microscope 30. Fluctuations in brightness in the coloured halo, which are not to be attributed to tooth filling residues, are reduced by the annular illumination effect. As a further alternative irradiation can be effected in the form of a line, as is illustrated in FIG. 9. In that case the irradiation device additionally includes a scanning device in order to be able to scan the tooth with the line. A scanning device can however also be provided when illumination in point form or circle form is involved, in particular if the point or circle cross-section is very small or the region of the tooth to be investigated is large.
  • Examination of the tooth 1 for tooth filling residues is effected with the operating microscope 30. It will be appreciated that the examination procedure can also be effected by means of an operating microscope when the irradiation unit is not integrated into the operating microscope but is in the form of an independent unit.
  • FIG. 6 shows a fourth embodiment of the apparatus according to the invention. This embodiment is designed for carrying out the method in accordance with the second embodiment of the method of the invention.
  • Illustrated here is an irradiation apparatus 40 which includes a light source unit 42 for producing white light and an optical irradiation means 41 for irradiating the tooth with the white light. The light source unit includes three light sources 43 a, 43 b, 43 c for producing red, green and blue light. For example lasers or LEDs can be used as the light sources 43 a, 43 b, 43 c. The light sources 43 a, 43 b, 43 c are connected by way of light guides 44 a, 44 b, 44 c to a mixer 45 in which the light is mixed in such a way that the mixed light appears white. The mixer 45 is connected to an optical irradiation means 41 by way of a further light guide 46. The optical irradiation means 41 is of such a configuration that the tooth can be irradiated with the mixed light, in particular over a large area and uniformly. In order to ensure uniform irradiation the optical irradiation means 41 is for example of such a design configuration that the beam cross-section in the radial direction involves the hat top profile shown in FIG. 8.
  • A fifth embodiment of the apparatus according to the invention is shown in FIG. 7. The apparatus 50 includes a light source 52 and an optical irradiation means 51, by means of which the tooth can be irradiated with the light from the light source in particular over a large area and uniformly. It is also advantageous in this embodiment if the beam cross-section involves a constant intensity distribution.
  • The light source 52 is of such a nature that its colour temperature can be varied by means of an adjusting device 53 connected to the light source. For the purposes of identifying tooth filling residues, the colour temperature can be varied by means of the adjusting device until a colour temperature is set, at which the tooth filling material differs from the tooth material. If the scattering or absorption characteristics of the tooth filling material are known, the colour temperature can also be already set prior to the irradiation procedure, in such a way that the tooth filling material can be recognised. In that case there is no need to search for the correct adjustment.
  • All the described embodiments can have an adjustment option for adjusting the intensity of the light used for the irradiation procedure in order to give the user the option of adjusting the intensity to a value which is pleasant for him and which guarantees an optimum distinction between tooth material and tooth filling material.

Claims (20)

1. An apparatus for identifying tooth-coloured tooth filling residues of a tooth comprising an irradiation device including a light source for irradiating the tooth with light characterised in that the light source is so designed to emit light whose spectrum has irregularly distributed wavelengths and includes at least one wavelength component which is absorbed or scattered by the tooth filling material differently from the tooth material in such a way that the tooth filling material is distinguished from the tooth material in respect of its brightness or in respect of its colour, wherein the distribution of the wavelengths in the spectrum is so selected that the spectrum has substantially a given colour temperature and associated with the light source is an adjusting device for adjusting the colour temperature of the light emanating from the light source, the colour temperature being selected to visually distinguish the tooth filling material with the naked eye.
2. The apparatus according to claim 1 characterised in that it includes an adjusting device for adjusting or attenuating the intensity of the light of the light source.
3. The apparatus according to claim 1 characterised in that the irradiation device is so designed that it permits local irradiation of the tooth and that the light source emits light with at least one wavelength component which is absorbed or scattered by the tooth filling material differently from the tooth material in such a way that the tooth filling residue differs from the tooth material in respect of its brightness.
4. The apparatus according to claim 3 characterised in that the irradiation device is in the form of a pen which includes the light source and which is so designed that it is to be held directly against the tooth.
5. The apparatus according to claim 3 characterised in that the irradiation device includes a light guide.
6. The apparatus according to claim 3 characterised in that the irradiation device is integrated into an operating microscope for observing the tooth.
7. The apparatus according to claim 6 characterised in that the irradiation device is so designed that the illumination point is displaced relative to the focal point of the operating microscope.
8. The apparatus according to claim 6 characterised in that the irradiation device is so designed that irradiation is effected in an annular configuration around the focal point of the operating microscope.
9. The apparatus according to claim 1 characterised in that the wavelength distribution is so selected that the mixture of the wavelengths represents white light.
10. The apparatus according to claim 9 characterised in that the irradiation device is integrated into an operating microscope.
11. The apparatus according to claim 1 characterised in that the irradiation device includes three monochromatic light sources, the light from each of which is of a different respective wavelength.
12. The apparatus according to claim 1 wherein the irradiation device is so designed that it irradiates the tooth in line form.
13. The apparatus according to claim 1 wherein the irradiation device is so designed that the light with which the irradiation operation is effected has an irradiation cross-section which in at least one direction has an intensity distribution with a constant portion.
14. The apparatus according to claim 13 wherein the irradiating device is so designed that it illuminates the tooth in point form and the point has an intensity distribution having a constant portion in the radial direction.
15. The apparatus according to claim 1 characterised in that the irradiation device is integrated into an operating illumination means.
16. The apparatus according to claim 1 characterised in that the irradiation device is in the form of an independent unit.
17. An operating microscope for observing a tooth comprising:
an observation means for observing the tooth having a focal point;
an irradiation device including a light source for irradiating the tooth with light characterised in that the light source is so designed to emit light whose spectrum has irregularly distributed wavelengths and includes at least one wavelength component which is absorbed or scattered by tooth filling material differently from the tooth material in such a way that the tooth filling material is distinguished from the tooth material in respect of its brightness or in respect of its colour, wherein the distribution of the wavelengths in the spectrum is so selected that the spectrum has substantially a given colour temperature;
an adjusting device associated with the light source for adjusting the colour temperature of the light emanating from the light source, the colour temperature being selected to visually distinguish the tooth filling material with the naked eye; and
an optical focusing means for focusing the light emanating from the light source on the tooth.
18. The operating microscope according to claim 17 characterised in that the optical focusing means is so designed that the light from the light source is focused on to an illumination point and the illumination point is displaced relative to the focal point of the operating microscope.
19. The operating microscope according to claim 17 characterised in that the optical focusing means is so designed that irradiation is effected in an annular configuration around the focal point of the operating microscope.
20. The operating microscope according to claim 17 characterised in that the optical focusing means is so designed that irradiation is effected in a form of a line and further comprising a scanning device for scanning the tooth with the line.
US12/172,322 2003-07-17 2008-07-14 Method and apparatus for identifying tooth-coloured tooth filling residues Abandoned US20080274437A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US12/172,322 US20080274437A1 (en) 2003-07-17 2008-07-14 Method and apparatus for identifying tooth-coloured tooth filling residues

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE10333515.3 2003-07-17
DE10333515.3A DE10333515B4 (en) 2003-07-17 2003-07-17 Method and device for identifying tooth-colored tooth filling residues
US10/892,019 US7445448B2 (en) 2003-07-17 2004-07-15 Method for identifying tooth-colored tooth filling residues
US12/172,322 US20080274437A1 (en) 2003-07-17 2008-07-14 Method and apparatus for identifying tooth-coloured tooth filling residues

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US10/892,019 Continuation US7445448B2 (en) 2003-07-17 2004-07-15 Method for identifying tooth-colored tooth filling residues

Publications (1)

Publication Number Publication Date
US20080274437A1 true US20080274437A1 (en) 2008-11-06

Family

ID=33560255

Family Applications (2)

Application Number Title Priority Date Filing Date
US10/892,019 Active 2025-05-25 US7445448B2 (en) 2003-07-17 2004-07-15 Method for identifying tooth-colored tooth filling residues
US12/172,322 Abandoned US20080274437A1 (en) 2003-07-17 2008-07-14 Method and apparatus for identifying tooth-coloured tooth filling residues

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US10/892,019 Active 2025-05-25 US7445448B2 (en) 2003-07-17 2004-07-15 Method for identifying tooth-colored tooth filling residues

Country Status (2)

Country Link
US (2) US7445448B2 (en)
DE (1) DE10333515B4 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070037113A1 (en) * 2005-08-10 2007-02-15 Scott Robert R Dental curing light including a light integrator for providing substantially equal distribution of each emitted wavelength
US9642687B2 (en) 2010-06-15 2017-05-09 The Procter & Gamble Company Methods for whitening teeth
US20120283712A1 (en) * 2011-02-03 2012-11-08 TRIA Beauty Devices and Methods for Radiation-Based Dermatological Treatments
US9427162B2 (en) * 2013-11-11 2016-08-30 Joshua Friedman Dental shade matching method and device
DK3064170T3 (en) * 2015-03-04 2021-08-23 Ivoclar Vivadent Ag Dental prosthesis blank and method of making a dental prosthesis
IT201900006228A1 (en) * 2019-04-23 2020-10-23 Pietro Ausiello Dental light for curing composites.

Citations (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4184175A (en) * 1977-02-09 1980-01-15 The Procter & Gamble Company Method of and apparatus for optically detecting anomalous subsurface structure in translucent articles
US4564355A (en) * 1984-01-09 1986-01-14 Dentonaut Lab, Ltd. Method and apparatus for the non-invasive examination of the tooth-jaw structure of a patient to determine the characteristics of unerupted teeth and to control nutritional intake pursuant thereto
US4600389A (en) * 1984-10-29 1986-07-15 Magnetic Activated Particle Sorting, Inc. Dental restoration method and composition therefor
US5211748A (en) * 1989-03-21 1993-05-18 National Research Development Corporation Identifiable dental restorative material
US5306144A (en) * 1992-01-14 1994-04-26 Kaltenbach & Voigt Gmbh & Co. Device for detecting dental caries
US5476379A (en) * 1993-11-04 1995-12-19 Disel; Jimmy D. Illumination system and connector assembly for a dental handpiece
US5759032A (en) * 1996-07-24 1998-06-02 Bartel; William B. Device for applying pressure to photocurable materials during polymerization
US5908294A (en) * 1997-06-12 1999-06-01 Schick Technologies, Inc Dental imaging system with lamps and method
US6171105B1 (en) * 1999-09-21 2001-01-09 Eg&G Ilc Technology, Inc. Dental-restoration light-curing system
US6208788B1 (en) * 1998-07-29 2001-03-27 Ultradent Products, Inc. Apparatus and methods for concentrating light through fiber optic funnels coupled to dental light guides
US6211626B1 (en) * 1997-08-26 2001-04-03 Color Kinetics, Incorporated Illumination components
US6290368B1 (en) * 1999-05-21 2001-09-18 Robert A. Lehrer Portable reading light device
US20010023057A1 (en) * 2000-03-17 2001-09-20 Hack Alexander Device for identifying caries, plaque, bacterial infectrion, concretions, tartar and other fluorescent substances on teeth
US6413084B1 (en) * 2000-04-28 2002-07-02 Ora Metrix, Inc. Method and system of scanning
US20030156788A1 (en) * 2001-07-10 2003-08-21 Thomas Henning Method and device for recognizing dental caries, plaque, concrements or bacterial attacks
US6769911B2 (en) * 2001-04-16 2004-08-03 Advanced Research & Technology Institue Luminescence assisted caries excavation
US20040254478A1 (en) * 2003-05-22 2004-12-16 De Josselin De Jong Elbert Fluorescence filter for tissue examination and imaging
US20050202372A1 (en) * 2004-03-09 2005-09-15 Rapczynski William T. Method and apparatus for visually differentiating between natural tooth structure and a restorative material
US6957907B2 (en) * 2003-04-11 2005-10-25 Ultradent Products, Inc. Illumination apparatus having a light-converting lens for increasing visual contrast between different oral tissues

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE442817B (en) * 1981-04-01 1986-02-03 Hans Ingmar Bjelkhagen DEVICE FOR OCCURRANTLY ACHIEVING A DISCRIPTION IN A LUMINISCENCE FOR A TANDY SURFACE
EP0113152A3 (en) * 1983-01-03 1985-07-03 North American Philips Corporation Method and apparatus for examining anomalies on surfaces of objects
DE9417470U1 (en) * 1994-10-19 1995-01-05 Fink Frank Prof Dr Device for determining structural changes in objects, in particular carious spots on teeth
DE19619067C2 (en) * 1996-05-13 2000-04-27 Ges Foerderung Spektrochemie Device for the detection of carious tooth substance and / or tooth-colored tooth restorations in particular

Patent Citations (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4184175A (en) * 1977-02-09 1980-01-15 The Procter & Gamble Company Method of and apparatus for optically detecting anomalous subsurface structure in translucent articles
US4564355A (en) * 1984-01-09 1986-01-14 Dentonaut Lab, Ltd. Method and apparatus for the non-invasive examination of the tooth-jaw structure of a patient to determine the characteristics of unerupted teeth and to control nutritional intake pursuant thereto
US4600389A (en) * 1984-10-29 1986-07-15 Magnetic Activated Particle Sorting, Inc. Dental restoration method and composition therefor
US5211748A (en) * 1989-03-21 1993-05-18 National Research Development Corporation Identifiable dental restorative material
US5306144A (en) * 1992-01-14 1994-04-26 Kaltenbach & Voigt Gmbh & Co. Device for detecting dental caries
US5476379A (en) * 1993-11-04 1995-12-19 Disel; Jimmy D. Illumination system and connector assembly for a dental handpiece
US5759032A (en) * 1996-07-24 1998-06-02 Bartel; William B. Device for applying pressure to photocurable materials during polymerization
US5908294A (en) * 1997-06-12 1999-06-01 Schick Technologies, Inc Dental imaging system with lamps and method
US6211626B1 (en) * 1997-08-26 2001-04-03 Color Kinetics, Incorporated Illumination components
US6208788B1 (en) * 1998-07-29 2001-03-27 Ultradent Products, Inc. Apparatus and methods for concentrating light through fiber optic funnels coupled to dental light guides
US6290368B1 (en) * 1999-05-21 2001-09-18 Robert A. Lehrer Portable reading light device
US6171105B1 (en) * 1999-09-21 2001-01-09 Eg&G Ilc Technology, Inc. Dental-restoration light-curing system
US20010023057A1 (en) * 2000-03-17 2001-09-20 Hack Alexander Device for identifying caries, plaque, bacterial infectrion, concretions, tartar and other fluorescent substances on teeth
US6413084B1 (en) * 2000-04-28 2002-07-02 Ora Metrix, Inc. Method and system of scanning
US6769911B2 (en) * 2001-04-16 2004-08-03 Advanced Research & Technology Institue Luminescence assisted caries excavation
US20030156788A1 (en) * 2001-07-10 2003-08-21 Thomas Henning Method and device for recognizing dental caries, plaque, concrements or bacterial attacks
US6957907B2 (en) * 2003-04-11 2005-10-25 Ultradent Products, Inc. Illumination apparatus having a light-converting lens for increasing visual contrast between different oral tissues
US20040254478A1 (en) * 2003-05-22 2004-12-16 De Josselin De Jong Elbert Fluorescence filter for tissue examination and imaging
US20050202372A1 (en) * 2004-03-09 2005-09-15 Rapczynski William T. Method and apparatus for visually differentiating between natural tooth structure and a restorative material

Also Published As

Publication number Publication date
US20050014106A1 (en) 2005-01-20
US7445448B2 (en) 2008-11-04
DE10333515A1 (en) 2005-02-03
DE10333515B4 (en) 2016-11-24

Similar Documents

Publication Publication Date Title
US20080274437A1 (en) Method and apparatus for identifying tooth-coloured tooth filling residues
US6111650A (en) Method and apparatus for color matching of slightly colored translucent objects such as teeth and dental prosthesis, in particular
US8382812B2 (en) Apparatus for photodynamic therapy and photodetection
KR100593098B1 (en) Apparatus and method for measuring optical characteristics of an object
KR101856909B1 (en) Apparatus for Measuring Skin Condition with Multiple Lights
CA1161120A (en) Method and apparatus for detecting the presence of caries in teeth using visible luminescence
US5174297A (en) Diagnostic apparatus for living tissues and medical treatment apparatus with diagnostic apparatus
US7583993B2 (en) Fluorescence image display apparatus
RU2446731C2 (en) Optical measuring device
JP5227811B2 (en) Ophthalmic equipment
CN102665559B (en) Excitation, detection, and projection system for visualizing target cancer tissue
JP4521587B2 (en) Optical diagnostic device with improved illumination uniformity
JPH05337142A (en) Detector for dental caries
JPH07427A (en) Method and device for determining color of light-transmitting, light-diffusing, and light-absorbing object, such as tooth
JP2001183304A (en) Device for quantitative evaluation of surface quality
WO2004029673A8 (en) Improved diagnostic fluorescence and reflectance
JP2009510473A (en) Raman instrument for measuring weak signals in the presence of strong background fluorescence
EP3431966B1 (en) Display device for photometric analyzer
KR101847435B1 (en) Device for real-time imaging of parathyroid
CA2264870A1 (en) Apparatus for the characterization of tissue of epithelial lined viscus
US10456028B2 (en) Apparatus for use in the measurement of macular pigment optical density and/or lens optical density of an eye
JPWO2018003263A1 (en) Observation apparatus and control method of observation apparatus
JP4278419B2 (en) Evaluation method of skin transparency
JPH11218447A (en) Colorimetric apparatus
EP3395234B1 (en) Apparatus for use in the measurement of macular pigment optical density of an eye

Legal Events

Date Code Title Description
STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION