WO2011035958A1

WO2011035958A1 - Dental treatment or dental examination device

Info

Publication number: WO2011035958A1
Application number: PCT/EP2010/060880
Authority: WO
Inventors: Christoph Hauger
Original assignee: Carl Zeiss Surgical Gmbh
Priority date: 2009-09-28
Filing date: 2010-07-27
Publication date: 2011-03-31
Also published as: DE102009043052A1

Abstract

The invention relates to a dental treatment or dental examination device, comprising a base body (3, 6) and a dental treatment or dental examination instrument (37) which is rotatably mounted in the base body (6). The device further comprises an OCT system for examining a depth region in the tooth, comprising an optical fiber (25) having a first fiber section (50) and a second fiber section (51) in which an OCT measurement beam can be guided. The first fiber section (50) is allocated to the base body (3, 6) and the second fiber section (51) is connected to the dental treatment or dental examination instrument (37), wherein the first fiber section (50) has an outlet end (52) and the second fiber section (51) an inlet end (56), the outlet end (52) of the first fiber section (50) and the inlet end (56) of the second fiber section (51) being arranged in such a manner that light of the OCT measurement beam can be transferred from the outlet end (52) into the inlet end (56) and vice versa. According to the invention, an optical element (57) is provided between the outlet end (52) of the first fiber section (50) and the inlet end (56) of the second fiber section (51).

Description

Description: Dental treatment or examination device

The invention relates to a dental treatment or -untersuchungsvorrichtung with a base body and with a dental or Zahnuntersuchtungsinstrument which is rotatably mounted in the body The dental treatment or examination device further includes an OCT system for examining a depth range in the tooth, which is an optical fiber with a The first fiber section is associated with the main body and the second fiber section is connected to the dental treatment or examination instrument. The first fiber section includes an exit end and the second fiber section has an entrance end. In this case, the first outlet end and the second inlet end are arranged such that light of the OCT measuring beam can be transferred from the outlet end into the inlet end and vice versa

A tooth consists essentially of three components, namely the dentin, also known as the dentin, the enamel, with which the dentin is covered for its protection, and the pulp, also referred to as dental pulp or colloquially tooth nerve, which contains the nerve fibers and blood vessels of the tooth. The pulp can be subdivided into the crown pulp, which runs through the tooth crown, and the root pulp, which runs through the root. The pulp tissue is extremely sensitive, for example to thermal stimuli. Temperatures above 42 ° C can damage the pulp tissue thermally, which can lead to the death of pulp tissue.

For the preparation of teeth is the knowledge of the size and extent of the

Crown pulp of interest to prevent inadvertent opening of the crown pulp when preparing a tooth. Radiographic imaging methods are often used to determine the pulp calculation. However, in radiological presentations, such as bite wing mounts, the actual dimensions of the pulp are often not reflected correctly. Especially in the area of the posterior molars (molars), the pulp calculation can be underestimated. From DE 102005 044889 AI a dental examination and / or Behandlungswerkzcug is known, which has a lumen in which an imaging catheter for receiving image data of an examination and / or treatment area is arranged. The imaging catheter is used to capture image data after a partial scan

Pulp removal in the root canal used. In particular, the imaging catheter can be an OCT catheter, ie a catheter for performing an optical coherence tomography.

US Pat. No. 6,419,484 B1 discloses another dental treatment device which comprises a base body in the form of a handle and a dental treatment instrument in the form of a drill. The dental treatment device further includes an OCT system for examining a depth range in the tooth. An optical fiber of the O CT system for guiding an OCT measurement beam is arranged in the base body and has an outlet end on a surface of the base body. The outlet end is designed such that an emerging OCT measuring beam impinges on the surface to be examined in front of the drill.

From DE 10 2007 063 419 AI a dental treatment or -Untsuchungsvorrichtung is known, which has a base body in the form of a drill head and a

Dental treatment instrument in the form of a drilling tool comprises. With the help of an OCT system, a depth range in the tooth can be examined and, in particular, a distance between a dentin and pulp boundary and the surface of the tooth determined so that the pulp is not opened during a treatment. In one embodiment, the OCT system comprises an optical fiber for guiding an OCT measuring beam with a first fiber section, which is arranged in the base body, and a second fiber section, which is guided in an axis of rotation of the drilling tool and rotates in operation with the drilling tool of an unspecified coupler is light of the OCT measuring beam from an exit end of the first fiber portion into

Entry end of the rotating second fiber section transferable.

In the case of an arrangement of a fiber section in a dental treatment or examination instrument which is rotatably mounted in a base body, there is a problem in reliably introducing an OCT measurement beam from the stationary base body into the rotating instrument during operation and as trouble-free as possible. An object of the present invention is therefore a dental treatment or - examination device with a rotatably mounted Zahnbehandlungs- or

To provide an examination instrument, which is characterized by a particularly reliable and reliable introduction of the OCT measuring beam into the instrument.

The object is achieved by a dental treatment or examination device having the features of claim 1.

According to the invention, an optical element between the outlet end of the first

Fiber portion and the entrance end of the second fiber portion provided. With the aid of the optical element, a beam shaping of the OCT measuring beam is possible upon entry into the second fiber section of the optical fiber and thus adaptation of the OCT measuring beam to the spatial conditions.

In one embodiment of the invention, the optical element is designed as imaging optics, by means of which the outlet end of the first fiber section can be imaged onto the inlet end of the second fiber section. This offers the advantage that the light of the OCT measuring beam can be introduced as completely as possible into the second fiber section

In a further embodiment of the invention, the Austrinkende of the first fiber portion and the inlet end of the second Faserab section are spaced from each other. Thus, the "dormant" fiber end and the rotating fiber end are spatially separated from each other, so that in operation the OCT measuring beam can be transferred from the first fiber section into the second fiber section

Reduces vibration transmission from the first fiber section to the second fiber section, so that a low-noise operation is enabled.

In further embodiments of the invention, the optical element is with the first

Fiber portion or the second fiber portion connected. In connection of the optical element to the first fiber section, the optical element rests in operation relative to the dental treatment or examination instrument, while in an arrangement in the second fiber section at least partially rotates with the dental treatment or examination instrument. The spatial separation between the first fiber section and the second

Fiber section remains. The optical element can also by means of a corresponding shaping of an outlet cross section of the first fiber section or an inlet cross section of the second fiber section to be executed.

In a further embodiment of the invention, the optical element is a grin lens

designed. As a result, the invention is compact.

In a further embodiment of the invention, a drill head is provided as a dental treatment or examination instrument. Dental drills are typically operated at high speeds, and signal transmission from a stationary part of the drill into the drill head is difficult to realize, particularly due to the vibrations that occur. By the beam shaping of the OCT measuring beam when entering the second

Fiber section, the present invention enables a quality improvement in the

Transmission.

In the following, embodiments of the invention will be explained in more detail with reference to drawings. In detail:

Fig. 1 shows a dental treatment or -Untsuchungsvorrichtung in the form of a schematic

Block diagram,

Fig. 2 is a known from the prior art embodiment of a dental treatment or -unthehehungsvorrichtung and

Fig. 3 shows an embodiment of a Zahnbehandlungs- invention or

Dental examination device.

A dental treatment or examination device known from the prior art, which is embodied as a dental drill, is shown schematically in FIG. The dental drill comprises a base body 1 with a handpiece 3 and a tool holder 6 and a dental treatment or examination instrument in the form of a drilling tool 37. The dental drill further includes an OCT system with a white light interferometer 7, an artifactor 9 and a control unit 13. The analysis device 9 and the control unit 13 are connected to the Weißhchtinterferometer 7 for receiving the interferometry signal or for the delivery of control signals. The white light interferometer includes a broadband light source 15 which has a short to very short coherence length. The light emitted by the light source is transmitted in the

Hereafter referred to as white light, even if the broadband spectrum of light does not necessarily need to give white light. It is only important that the light source is broadband, since the temporal coherence of the light decreases with increasing bandwidth. The white light interferometer 7 further comprises a reflectance beam branch 17 and a measuring beam branch 19, a splitter and superimposed T 21 present in the present invention

Exemplary embodiment is shown as a beam splitter, and a detector 23rd

In the white light interferometer 7, the white light emitted by the broadband light source 15 is split by the beam splitter 21 into a measuring beam and a reference beam, which are then coupled into the measuring beam branch 19 or the reference beam two g 17. In the reference branch 17, the reference beam is directed to a reflector 29 and from there is directed back to the beam splitter 21

Optical fiber 25 is directed to the drilling tool 37 and explained there in more detail below there on the tooth A part of the measuring beam is reflected by structures in the tooth and passed through the optical fiber 25 back to the beam splitter 21. There, the reflected measuring beam is superimposed on the reflected reference beam and both beams are fed to the detector 23. In the detector 23, a distance of the structure in the tooth from a surface of the tooth is determined by means of a Fourier domain or a time-domain analysis

In Figure 2, the handpiece 3 with the tool holder 6 and the drilling tool 37 of the dental drill of Fig. 1 are shown in detail

Also shown in FIG. 2 is a tooth 39 in which the pulp 41, the dentin 43 and the enamel 45 can be seen. The drilling tool 37 is used,

Tooth enamel 45 and dentin 43 aufzubohren, for example, to remove tooth decay. The drilling tool 37 should not reach the sensitive pulp 41. With the aid of the OCT system, a distance between a surface 47 of the tooth 39 and the boundary layer between the pulp 41 and the dentin 43 can be determined, so that when it falls below a

Minimum distance appropriate measures to prevent opening of the pulp, for example, an automatic stopping of the drilling tool 37 or generating a visual or audible warning signal can be taken. To supply the OCT measuring beam to the tooth 39, the optical fiber 25 of the

Measuring beam branch 19 through the handpiece 3, the tool holder 6 and the drilling tool 37 to an outlet opening 31 of the drilling tool 37 out.

In Fig. 3, the erfÜKtungsgemäße embodiment of the optical fiber 25 in the region of

Tool holder 6 and the drilling tool 37 shown. In this area, the optical fiber 25 includes a first fiber portion 50 and a second fiber portion 51.

The first fiber section 50 is guided in the embodiment shown in FIG. 3 outside the handle 3 and the tool holder 6 and attached to an outlet end 52 at a connection 53 of the tool holder 6. In a modified exemplary embodiment, the first fiber section 50 is guided at least partially within the handle 3 and / or the tool holder 6, as shown for example in FIG. In any case, the first fiber section 50 is preferably fixedly connected to the handle 3 and / or the tool holder 6, so that relative movements between the first fiber section 50 and the

Handle 3 and the tool holder 6 are largely suppressed. The first fiber section 50 has an exit end 52, at which the OCT measuring beam can be diverted from the first fiber section.

The second fiber section 51 is arranged along a rotation axis 54 in the boring tool 37 and connected to the boring tool 37 such that it rotates with rotation of the boring tool 37 about the rotation axis 54. At an entry end 56 of the second fiber section 51, the OCT Measuring beam from the relative to the second

Fiber portion 51 resting first fiber portion 50 in the second fiber portion 51 of the optical fiber 25 can be introduced. The OCT measuring beam can subsequently be guided through the second fiber section 51. Via an outlet opening 31 of the drilling tool 37, the OCT measuring beam can be directed to a tooth surface as already explained in greater detail above. Between the exit end 52 of the first fiber section 50 and the entry end 56 of the second fiber section 51, an optical element in the form of imaging optics 57 is arranged, which in this exemplary embodiment is fixedly connected to the tool receptacle 6 and which comprises two lenses 58, 59. A first lens 58 collimates an OCT measuring beam emerging from the outlet end 52 of the first fiber section 50 and a second lens 59 imaged on the entrance end 56 of the second fiber section 51. The illustration of the outlet end 52 on the inlet end 56 ensures that the light emerging from the outlet end 52 is almost completely introduced into the second fiber section 51. In the reverse imaging direction, this arrangement further ensures that the light reflected on the tooth surface and in the second Fiber portion 51 back fed part of the OCT measuring beam is almost completely transferred into the first fiber section 50. The arrangement of the first lens 58 and the second lens 59 described in this embodiment also has the advantage that the exit end 52 of the first Fascrab section 50 and the entry end 56 of the second fiber section 51 are arranged at a spatial distance from each other, so that a mechanical Contact between the dormant first

Fiber section 50 and the rotating second fiber section 51 is avoided and the risk of transmission of interference, for example in the form of vibrations or thermal loads between the two fiber sections is reduced. The lenses 58, 59 are preferably designed as Grin lenses.

In this exemplary embodiment, the imaging optics comprise two refractive optical elements in the form of lenses 58, 59. For purposes of beamforming, when the OCT measurement beam passes from the first fiber section to the second one, the beam can be shaped without restriction of generality

Fiber section but also reflective optical elements or other refractive optical elements or combinations of refractive and or reflective optical elements may be provided.

In a modified, not shown Amfühnmgsbei play the first lens is connected to the Werkzeugaufhahme and rests relative to the second fiber portion, and the second lens is connected to the second fiber portion. In another embodiment, the optical element (optionally with the two lenses) is associated with the second fiber section so that it rotates during operation with the drilling tool. The spatial separation between the first fiber section and the second fiber section is maintained.

In further modified embodiments, not shown, the device according to the invention is a pure examination device with a rotating

Examined instrument in which, for example, the OCT measuring beam is directed at a tooth surface at an angle to the axis of rotation of the examination instrument, so that lateral boundaries of a channel in the tooth are scanned by OCT. In in turn, another, not shown embodiment is as

Dental treatment instrument provided a polishing head.

In a dental treatment or examination device according to the invention, a stationary fascia is spatially separated from a rotating fiber section and an OCT measurement beam is transmitted from the stationary fiber section to the rotating fiber section and vice versa via an optical element. Thus, a transmission quality of the signal is improved and a hazard a transmission of physical disturbances, for example in the form of vibrations between the two fiber sections is reduced.

Claims

Claims:

A dental treatment or examination apparatus comprising a base body (3, 6) and a dental treatment instrument (37) rotatably supported in the base body (6) and an OCT system for examining a depth range in the tooth comprising an optical fiber (25) having a first fiber portion (50) and a second fiber portion (50)

Fiber portion (51), in which an OCT measuring beam is guided, wherein the first fiber portion (50) is associated with the base body (3, 6) and the second fiber portion (51) is connected to the dental treatment or examination instrument (37) and the first fiber section (50) comprises an exit end (52) and the second fiber section (51) comprises an entrance end (56) and the exit end (52) of the first fiber section (50) and the entrance end (56) of the second fiber section (51). are arranged such that light of the OCT measuring beam can be transferred from the exit end (52) into the entry end (56) and vice versa, characterized in that an optical element (57) is arranged between the exit end (52) of the first fiber section (50). and the entrance end (56) of the second fiber section (51).

2. Dental treatment or examination device according to claim 1,

characterized in that the optical element is designed as imaging optics (57), by means of which the

Exit end (52) of the first fiber portion (50) on the entrance end (56) of the second fiber portion (51) is imaged. Dental treatment or examination device according to one of claims 1 or 2, characterized in that

the exit end (52) of the first fiber section (50) and the entrance end (56) of the second fiber section (51) are spaced apart from each other. Dental treatment or examination device according to one of claims 1 to 3, characterized in that

the optical element (57) is connected to the first fascia section (50) and / or to the second fiber section (51). Dental treatment or examination device according to one of claims 1 to 4, characterized in that

the optical element (57) is designed as a grin lens. Dental treatment or examination device according to one of claims 1 to 5, characterized in that

as a dental treatment or examination instrument a drilling tool (37) is provided.