(dental) surface mapping and generation

p0001The present invention relates to a surface detection device and a method for surface detection. More specifically, and with preference, the present invention is concerned with such a device and method for detecting surfaces of teeth.

p0002The basic technologies on which the present invention is based or combinable are disclosed in the Laid-open Laws <patcit id="pcit0001" dnum="DE4439307A1"><text>DE 44 39 307 A1</text></patcit> and <patcit id="pcit0002" dnum="DE19721688A1"><text>DE 197 21 688 A1</text></patcit> Is disclosed.

p0003The <patcit id="pcit0003" dnum="US5338198A"><text>U.S. Patent 5,338,198</text></patcit> Discloses the generation of a three-dimensional model of the teeth and the arch of a patient's jaw. A casting impression is applied to a table in the xy plane and scanned with a laser beam. In the y-direction, a discrete and in the x-direction a continuous shift occurs during the scanning. The table can also be tilted. The various scan data sets can be compared and correlated for a more accurate calculation of the shape of the imprint.

p0004The invention is as defined in the claims.

p0005SUMMARY OF THE INVENTION The invention provides a surface acquisition device having means for expediting and / or cost optimization comprising a pulsed laser for exposure, wherein the means for processing and / or cost optimization are designed such that two fields which show different positions or views are evaluated .

p0006In this case, it is preferably provided that the devices for drainage and / or cost optimization include raw material recovery devices, and / or the devices for drainage and / or cost optimization comprise an automated control of the intensity of a laser light used.

p0007Further alternative or additional embodiments of a surface-detection device according to the invention, in particular for obtaining surface data of teeth, are that the devices for expediting and / or cost optimization include devices for the export of a calibration procedure with evaluation of superimposition errors at matching points and / or that an image recording device, In particular a CCD chip, is arranged in such a way that lines are recorded in consideration of the

p0008Scheimpflug angle are perpendicular to the travel direction of the measuring table.

p0009A further variant of a surface detection device, in particular for obtaining surface data of teeth according to the invention, consists in the fact that the means for the removal and / or cost optimization comprise means for archiving, in particular, three-dimensional jaw data and / or for the resemblance of the upper and lower jaws.

p0010Particularly preferably particularly mechanical configurations of the surface detection device are based on the disclosure content of the <figref idrefs="f0004">FIGS</figref> and <figref idrefs="f0005">4</figref> And / or 5, 6 and 7 and the related description.

p0011In an example which is not part of the invention, it is further preferred if, in the case of the surface detection device and a production device, in particular for the production of dental prosthesis, the means for the removal and / or cost optimization means for optimizing the preparation of at least one tooth stump for the production and setting up of a dental stump Tooth prosthesis thereon and / or devices for taking account of the abutment of the upper and lower jaw.

p0012The surface detection methods for obtaining the above-mentioned object of the invention and / or generation methods not according to the invention are characterized in that they use one or more of the above-described devices or function accordingly analogously.

p0013In one example, which is not part of the invention, a patient data archiving system is provided which is characterized by a chip card and / or decentralized data storage, in particular for dental data.

p0014Individual aspects of the invention are explained in more detail below.

p0015In accordance with one aspect of the present invention, the invention relates to surface-detection technologies, devices and methods as set forth in the above-mentioned publications incorporated herein by reference, and hereinafter referred to as "scanners", in combination with For example a milling machine, a raw material recovery is provided. Together with the milling machine and suitable EDP, the scanner forms a CAD-CAM system, in particular for producing gold or platinum tooth replacement. The raw material recovery can preferably be realized by the fact that the milling machine, which is used for example, is equipped with devices, for example, for extracting gold or platinum dust / chips. In view of the high cost of the raw materials gold or platinum, this advantageously results in a substantial reduction in the cost of producing gold or platinum tooth replacement.

p0016The scanner technology disclosed in the publications cited at the outset is not further improved according to the invention.

p0017On the one hand, this is achieved by automatic regulation of the intensity of the laser light used. The reflectivity of the tooth surface to be measured, for example, is preferably determined via the intensity of the light, for example, taken by a CCD chip. Based on the result of the determination, the intensity of the laser light is then readjusted. The improvement of this embodiment consists in the fact that measurement errors due to under or over-control of the measuring signal are thereby reduced.

p0018In the context of the present invention, the scanning technology is improved on the other hand by a speed increase by evaluating, instead of a frame from the camera / CCD chip consisting of two composite half images, two such half images which show different views. The different views are produced by various relative positions of the surface to be detected, for example, of a tooth and the device for receiving this surface (eg a camera with one or a single CCD chip).

p0019In particular, the above improvement but generally the scanning technology used can advantageously be further developed in that, similarly to a stroboscopic effect, the laser used is pulsed in a pulsed fashion and, for example, the table carrying the object whose surface is to be detected, such as a tooth or a laser beam Model thereof, in particular continuously. By means of the pulsed laser beam, snapshots or "recordings" are produced from each relative position of the object and camera since the object appears to be able to be captured by the camera during the short exposure time with a laser beam pulse. Particularly preferably, each individual laser pulse is coupled to the image of a field.

p0020A still further improvement according to the invention of the scanner technology consists in a calibration procedure which corrects various spatial distortions of the determined measured variables. A body is measured from different views. The measurements are put together using the matching algorithm. The superimposition errors occurring at different points of the object during this collation are analyzed to the extent that deviations in all spatial directions are detected. Calibration errors result from these deviations from which calibration parameters are calculated in all spatial directions and spatial rotations. These calibration parameters can then be taken into account automatically by the EDP during further measurements, as a result of which an increased measurement accuracy is advantageously achieved. Further details can be derived from the method described in the<figref idrefs="f0001 f0002">FIG</figref> Illustrated embodiment.

p0021Further, the scanner technology according to the above-described prior art is improved by the invention by arranging a CCD chip (or generally a surface image capturing device) such that, for example, camera lines are taken into account perpendicular to eg the direction of travel of the measuring table, taking into account the Scheimpflug angle On which the object to be detected is installed. Further details are given in the exemplary embodiment according to FIG<figref idrefs="f0002 f0003">FIG</figref> Respectively. This results in a better utilization of the measuring field for the measurement, for example of teeth, whereby it is to be noted that commercially available chips are not square.

p0022The known scanner technology can also not be improved according to the invention in that travel and pivot axes of the object carrier, object and / or camera are provided and arranged according to the present invention in such a way that insight into all undercuts occurring in the jaw, For example in the area of ​​tooth surface detection. This has the advantage that a fully automatic measurement / measurement strategy can be used.

p0023According to a further aspect of the present invention, various computer modules are advantageously used, for example, in various fields of dental medicine.

p0024Thus, the present invention provides a scanner technology which is equipped with an EDV, preferably in the form of a standard computer with special software as a control device, which is suitable for archiving, for example, three-dimensional jaw data, in particular surface data. The archiving serves to replace previous archiving forms of such data in the form of gypsum models. In many areas of dental medicine it has hitherto been necessary to store gypsum models of patients for up to 10 years, resulting in an enormous space requirement. However, the electronic archiving of these data not only provides a solution to the space requirements, but also allows a faster, simpler and more cost-effective use of the archived data. For example, it is possible to record and archive 3D measurement data from previously healthy tooth surfaces. This makes it possible, after years, for example when a tooth has to be replaced, to reconstruct the tooth in the form of a dental prosthesis, which can be produced, for example, by means of the archived data by means of the milking technology of its surfaces.

p0025However, an electronic archiving of jaw / dentition data can be advantageously used in many other respects. Thus, by means of a suitable EDV, these data enable a resemblance of the mating of upper and lower jaws. In particular, this can be produced by first measuring the lower jaw, then placing a bite register (imprint in the patient's mouth while it bites) on the lower jaw and measuring it again. Both tooth surfaces are thus determined in the bis-situation. Both data sets can be visualized separately or together and all associated dental analyzes, for example, can be carried out qualitatively or quantitatively (in the form of distance or volume measurements). In addition, the complete upper jaw can also be measured by means of the bite registration and, for example, a matching software. Chewing movements can also be simulated by recording the jaw movement and bite registration on the computer. The referencing of the measurement data of the upper and lower jaw can also be used for the modulation of dentures in connection with the CAD-CAM technology.

p0026A non-inventive variant consists in a scanner technology which is equipped with an EDV such as, for example, a standard computer with a corresponding software as a control device, in order to imitate the positioning of upper and lower jaws with special orientation for orthodontic treatment can. A treatment plan for, for example, a brace can be simulated by dividing the dentition into tooth groups as far as individual teeth, for example in the software. Such group / individual teeth can be moved and the end positions simulated. This allows answers to questions as to whether there is any space available on the jaw comb and how the bite will look after the treatment. Additional handling control is possible by means of other EDP / software devices which can be modularly combined. After periods of time a jaw can be scanned again and again. The temporally successive recordings can then be played as interpolated "film". This allows a comparison of the course of the actual treatment with the planned treatment and the establishment / implementation of corrections. Such recordings can also be archived and, for example, facilitated in the case of processes. It also facilitates and accelerates communication with experts and cash registers.

p0027A further non-inventive point of view is a scanner technology which is equipped with a computerized / electronic control system (for example by software) in order, for example, to be able to sense the ablation of the upper and lower jaws with special alignment for the maxillary surgery. Within the scope of this aspect, the inclusion of measurement data of the jaw bone (determined, for example, by means of a computer tomograph) is provided by means of suitable matching software. The treatment planning (eg an operation of the jaw) is simulated by dividing the dentition, the jaw and the jawbone into tooth / jaw section groups (up to individual teeth) in software, for example. The groups / individual teeth can be moved and the end positions simulated. This allows answering questions as to whether a required space is available and how the patient will look after the treatment. In this case, a further EDP / software module can be used for a treatment control. After expiration of time sections, the current state is scanned. The recordings over time can be played as interpolated "film". The course of the actual treatment can be compared with the planned treatment and any necessary corrections can be derived therefrom. Advantageously, this aspect allows the planning and simulation of implants. Archived recordings to simplify the process in case of possible processes as well as easier and faster communication with experts and cashiers are also available as additional advantages.

p0028A non-inventive example is finally a patient data carrier, such as, for example, a chip card, which contains all personal health and disease data. Such an individual data carrier can be integrated into an administration and archiving system which, in particular, contains decentralized storage devices for archiving large amounts of data which can be accessed by access means on the data carrier. For example, dental patient data, which can contain 3D jaw and single tooth data of tooth surfaces and internal superstructures of individual teeth, as well as generation data of inserted dentures (material and, for example, milling data), can be archived and easily made available. In addition, health insurance data, digital radiographs, formerly and up-to-date physicians and in general the patient's entire medical history are stored. Within the scope of the invention, special reading and evaluation devices can also be provided and possibly integrated in the system. The benefits include, for example, double archiving in the patient, improved traceability options for health insurance funds and data availability, even when changing the place of residence.

p0029A non-inventive example is a further variant / embodiment for the realization of a pulsed measurement, as already shown in principle above.

p0030A corresponding surface acquisition device or device consists, for example, of a line articulation, a CCD camera, a frame grabber card and a laser line module. For data acquisition, the laser line is permanently projected onto the measuring object. The measuring table moves the object step by step under the measuring arrangement (laser line and CCD chip). After each step a measurement takes place.

p0031The previous exact sequence is as follows: The measuring table moves into a starting position and stops. The object must be at rest so that no "jiggling" of the image results in measurement inaccuracies. Then, the CCD camera reads out one line (frame) and passes the signal to the frame grabber card. The table is then accelerated (approach ramp). The table is then braked again and stopped in a predetermined position (braking ramp). The CCD camera then reads out the next line. This overall process takes place under blackout. The laser diode can only be adjusted to a certain power so that the signal does not exceed.

p0032For example, not a part of the invention, the laser line is projected stroboscope-like on the object to be measured, ie, light flashes are regularly thrown onto the object in the form of a laser line. The measuring table continuously moves the object under the measuring arrangement (laser line, CCD chip). Simultaneously with each light flash, a measurement takes place. In particular, the controlled / supervised speed measuring table travels with the flash control. A flash is emitted at preferably regular intervals (time or travel distance of the table) and at the same time a field of the CCD chip is read out. This signal is transmitted to the frame grabber card and evaluated by means of special software. The flash time is so short that a "wobble", which could result from the continuous table movement, is negligible.

p0033With the above variant, the measuring method is accelerated by a factor of 5 since the starting and braking times of the table are omitted and the light flashes can be clocked so fast that half-images can be read out. A further advantage is that the control can be made more cost-effective since only a uniform feed is ensured and no exact rest position has to be set. It is also advantageous that the previous opto-mechanical arrangements can be further used, since the present invention can be implemented with regard to control, regulation and software for the components. Furthermore, it is advantageous that the lightning used is essential Is more intense than the previously used laser signal, whereby the measurement can also take place in daylight and the measuring space does not have to be darkened, which considerably reduces the work and their expenditure and time requirement, especially when exchanging measuring objects.

p0034In addition to the above-described technical specifications for the subject of "stroboscopes", etc., mechanical designs are also within the scope of the invention, which in their concept as well as concrete configurations and also operating methods are considered in combination and also in themselves individually as protective and protective.

p0035In particular, compared to the technical state of the device for manufacturing a dental prosthesis according to the invention <patcit id="pcit0004" dnum="EP98115809A"><text>EP 98115809.0</text></patcit> The present invention includes a number of concepts and designs which drastically discourage a corresponding device in the manufacture and make it more reliable and overall improvements compared to the technical teaching in the art <patcit id="pcit0005" dnum="EP98115809A"><text>EP 98115809.0</text></patcit> Of the population. Furthermore, these aspects of the present invention provide advantageous and preferred further developments and combinations of the embodiments described in the<patcit id="pcit0006" dnum="DE4439307A1"><text>DE 44 39 307 A1</text></patcit> and <patcit id="pcit0007" dnum="DE19721688A1"><text>DE 197 21 688 A1</text></patcit> , The complete content of which, as well as that of the Disclosure Notice <patcit id="pcit0008" dnum="EP98115809A"><text>EP 98115809.0</text></patcit> In so far as to avoid mere identical repetition in the present documents in the latter is hereby incorporated by reference in its entirety. The individual features and feature combinations, in particular, but not necessarily or exclusively, are to be combined with the stroboscope technique described above.

p0036Further preferred and advantageous embodiments of the invention result from the individual claims and their combinations.

p0037The invention is explained in more detail below by way of example only with reference to exemplary embodiments, with reference to the drawing in which:<dl id="dl0001"><dt>1 a, 1 b</dt><dd>Is a schematic plan view of a jaw, respectively, front view of a jaw with prior art drawing strips,</dd><dt>1 c, 1 d</dt><dd>Is a schematic plan view of a jaw, respectively, front view of a jaw with drawn-in scanning strips according to the invention, </dd><dt>FIG</dt><dd>Is a perspective schematic view of a measuring object in the form of a tooth,</dd><dt>FIG. 2b</dt><dd>A schematic view of the measuring object from the <figref idrefs="f0002">FIG</figref> With the scanning strips shown in the prior art,</dd><dt>FIG. 2c</dt><dd>12 is a schematic view of a signal image of a scanning line from FIG <figref idrefs="f0003">FIG. 2b</figref> is,</dd><dt>2d</dt><dd>A schematic view of the measuring object from the <figref idrefs="f0002">FIG</figref> With drawn-in scanning strips according to the invention,</dd><dt>2e</dt><dd>12 is a schematic view of a signal image of a scanning line from FIG <figref idrefs="f0003">2d</figref> is,</dd><dt>FIG</dt><dd>Is a schematic perspective view of an embodiment of a surface detecting device obliquely from above,</dd><dt>FIG</dt><dd>7 is an enlarged view of a portion of FIG <figref idrefs="f0004">FIG</figref> is,</dd><dt>FIG</dt><dd>12 is a schematic perspective view of the embodiment of the surface detection device from FIG <figref idrefs="f0004">FIG</figref> Obliquely from above in a different setting and enlarged,</dd><dt>FIG</dt><dd>12 is a schematic perspective view of the embodiment of the surface detection device from FIG <figref idrefs="f0004">FIG</figref> Obliquely from below and enlarged,</dd><dt>FIG</dt><dd>12 is a schematic perspective view of the embodiment of the surface detection device from FIG <figref idrefs="f0004">FIG</figref> Obliquely from below and enlarged as well as opposite the view from the <figref idrefs="f0007">FIG</figref> Is slightly rotated,</dd><dt>FIG</dt><dd>Is a graphical representation of a jaw with schematically drawn-in positions of measuring strips on the basis of data scanned according to the invention,</dd><dt>FIG</dt><dd>A graphical representation of the jaw from the <figref idrefs="f0009">FIG</figref> According to the invention,</dd><dt>FIG</dt><dd>Is a schematic partial view of a jaw for explaining another aspect of the invention, </dd><dt>FIG</dt><dd>12 is a schematic side view of a chewing or bis-simulator illustrating another aspect of the invention, and FIG</dd><dt>FIG</dt><dd>A schematic side view of a jaw from the <figref idrefs="f0010">FIG</figref> In a surface detecting means.</dd></dl>

p0038DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the individual figures of the drawing, the same or similar or similar or similarly acting parts are provided with the same reference symbols or are shown in a comparable manner, so that parts and their combinations, functions and modes of action are also known to one skilled in the art from the consideration of the figures of the drawing alone And / or the data described in the following may, if necessary, be readily accessible, even if no references between individual figures and / or between figures and text are explicitly indicated or illustrated.

p0039First, a conventional measuring method is explained to understand the function of a corresponding apparatus. This measuring method is used, for example, by the company DCS Forschungs- und Entwicklungs AG, Allschwil, Switzerland, and was also publicly presented in 1999. Within the scope of the present invention, this measuring method is significantly improved.

p0040In the <figref idrefs="f0001 f0002">FIG</figref> and <figref idrefs="f0002 f0003">2</figref> A scanning of a jaw K in a plan view or a front view is schematically illustrated. For example, five measuring strips S1, S2, S3, S4 and S5 are detected side by side. The five measuring strips S1 to S5 overlap in areas B, which are located in the<figref idrefs="f0001">FIG</figref> Shaded and in the <figref idrefs="f0001">FIG</figref> For the sake of clarity; The<figref idrefs="f0001">FIG</figref> Serves only to illustrate the position of the measuring strips S1 to S5 in the front view of the jaw K as well as the direction of the scanning radiation according to the arrows P. The overlapping regions B enable the data of the individual measuring strips to be combined by matching methods to form an overall image of the jaw K.

p0041A variant of the above technology according to the invention is described in the <figref idrefs="f0002">1 c and 1 d</figref> Also shown in a plan view and a front view, respectively. In this method and with the corresponding devices, measuring strips S6, S7, S8, S9, S10, S11, S12 and S13 are produced, which however only consist of so-called half images, so that more measuring strips than in the variant according to the<figref idrefs="f0001">1a and 1b</figref> Generated and treated, but these measurement strips do not have much less data. The position of the measuring strips S6 to S13 is, in the top view of FIG<figref idrefs="f0002">1c</figref> With respect to the jaw K. The irradiation directions are exemplified by the arrows P1, P2, P3 and P4 for the measuring strips S6, S11, S13 and S10 in FIG<figref idrefs="f0002">1d</figref> Schematically. In the<figref idrefs="f0002">FIG. 1 c</figref> Overlapping regions B of the individual adjacent measuring strips are again drawn in as shaded lines. By means of the irradiation directions for the individual measuring strips, which are modified with respect to the prior art, precise data of the jaw K are obtained, with a lower data and processing volume than in the prior art by using only half-images.

p0042A single measuring object in the form of a tooth Z is shown schematically in a perspective view in FIG <figref idrefs="f0002">FIG</figref> Is shown as being installed on a measuring head M, which for this purpose is, for example, filled with a kneaded mass into which the tooth Z is inserted with its lower end (not visible).

p0043For this measurement object Z is shown in FIG <figref idrefs="f0003">FIG. 2c</figref> The position of measuring strips or measuring lines S is shown schematically, and the <figref idrefs="f0003">FIG. 2c</figref> Shows the signal image for a measuring strip or a measuring line Sx in which only one measuring point Dx is obtained. In the<figref idrefs="f0003">FIG. 2b</figref> The readout direction (line direction) is also indicated by the arrow A1. The sum of all measuring strips or measuring lines S forms the surface of a chip C as an image recording device, which can be, for example, a CCD chip or any other camera device.

p0044On the other hand, a plurality of measuring points, eg Dy1 and Dy2 or Dza to Dzn, are obtained in a measuring line or in a measuring strip S according to the invention, such as the <figref idrefs="f0003">FIGS. 2d and 2e</figref> , Which are representations analogous to the <figref idrefs="f0003">FIG. 2b</figref> Or 2c. The read-out direction is, as shown by the arrow A2 in FIG<figref idrefs="f0003">2d</figref> And the chip C as well as the position of the measuring strips or measuring lines S are therefore rotated by 90 ° in comparison with the prior art. By means of this arrangement according to the invention, two measuring points Dy1 and Dy2 are obtained in the measuring line Sy. The measurement in the line Sz even leads to a plurality of measuring points Dza to Dzn. For the evaluation, the chip arrangement, as in the prior art (see FIG<figref idrefs="f0003">FIG. 2b</figref>) Are recalculated and simulated. The readout direction obtained again as in the prior art, however, again contains, for each line or line, a plurality of measuring points, which can be computationally detected as initially 1 st point, then 2 st point, etc. By this aspect of the invention, It is still possible to obtain more information for the half images, so that the accuracy of the invention is still increasing compared to the above-mentioned prior art.

p0045In the <figref idrefs="f0004">FIG</figref> and <figref idrefs="f0005">4</figref>, Which is an enlarged view of a part of FIG <figref idrefs="f0004">FIG</figref> A surface detection device 1 is shown with a laser optics 4 from which a laser line beam L emanates. The intersection point of the laser line beam L with the rectangular image field F emanating from the objective defines the measuring field F. Each object to be measured must be passed through this measuring field F. This detail also applies to the embodiments according to the<figref idrefs="f0006">FIG</figref>, <figref idrefs="f0007">6</figref> and <figref idrefs="f0008">7</figref>, Even if it is no longer shown there for display purposes of the other features. In this respect, in order to avoid repetitions during the subsequent referral to the<figref idrefs="f0006">FIG</figref>, <figref idrefs="f0007">6</figref> and <figref idrefs="f0008">7</figref> No longer received; However, the use of this technique can be recognized and understood by a person skilled in the art as well as being applicable there.

p0046In the following, as far as the design is identical or comparable, in order to avoid repetitions, <figref idrefs="f0006">FIG</figref>, <figref idrefs="f0007">6</figref> and <figref idrefs="f0008">7</figref> Reference.

p0047The "traversing" of the measuring field F is performed by means of a linear guide 83 (or reference symbol 4 'in the <figref idrefs="f0006">FIG</figref> and <figref idrefs="f0007">6</figref>). In order to be able to position a plurality of individual objects, such as, in particular, teeth, under the measuring field, a turntable 33 (or reference symbol 5) rotates in the<figref idrefs="f0006">FIG</figref>, <figref idrefs="f0007">6</figref> and <figref idrefs="f0008">7</figref>) From measuring head 84 to measuring head 84 (in the <figref idrefs="f0006">FIG</figref> The measuring heads are designated by reference numeral 8). In the<figref idrefs="f0004">FIG</figref> Only two measuring heads 84 are shown by way of example (also in FIG <figref idrefs="f0006">FIG</figref> Eg only two measuring heads 8), whereby, for example, seven pieces can be mounted as a whole.

p0048If a mortar 84 (or 8 in FIG <figref idrefs="f0006">FIG</figref>) In the measuring field, the rotation of the large turntable 33 (or 5 in the <figref idrefs="f0006">FIG</figref>, <figref idrefs="f0007">6</figref> and <figref idrefs="f0008">7</figref>). The turntable 33 (or 5 in the<figref idrefs="f0006">FIG</figref>, <figref idrefs="f0007">6</figref> and <figref idrefs="f0008">7</figref>) Is thus only used for positioning the individual tines 84 (or 8 in FIG <figref idrefs="f0006">FIG</figref>) And / or a jaw, which will be discussed later. The measurement itself takes place, as explained above, by means of a linear movement of the measuring table 53 on the linear bearings 83 or 4 '(<figref idrefs="f0006">FIG</figref>).

p0049A measuring strip is formed which sees only one side of the tooth to be measured. In order to be able to detect further measuring strips from further viewing angles, the pot 84<figref idrefs="f0006">FIG</figref>) Between the individual measurements are rotated around their own axis. This leads, for example, to eight views or the pot 84 (or 8 in the<figref idrefs="f0006">FIG</figref>) Is rotated between the measurements by 45 ° about its own axis. In this case, eight measuring strips are produced from different views. Parts of the obtained surface information are obtained in several measuring strips. By means of these overlapping regions, suitable devices or methods in the form, for example of a matching software already explained above, can form the individual measuring strips into a complete 3D surface image of a single tooth with high measuring accuracy.

p0050With these data, the inner data set of a tooth crown can now be milled. In addition to individual crowns, multiple single teeth can also be combined into one bridge. In order to be able to mill bridges, the spatial position of several individual crowns must be detected as quickly as possible. For this purpose, a complete jaw model is measured in the same way as the single tooth. It is placed on an additional rotary table 26, which is mounted in the rotary table 5 in the<figref idrefs="f0006">FIG</figref> is provided.

p0051The result is shown in Fig <figref idrefs="f0009">FIG</figref> to see (the direction of the measuring strips are five white lines (exemplarily given the designations 11, 12 and 13 and in the rest only the lines are drawn can be seen). This measurement result not containing all the data of the jaw, but are outside of sufficiently many Data to make them automatically with the data of the individual stumps.

p0052Thereafter, a software search is started with suitable devices or, as the case may be, a method of matching the data. The results can be seen in the picture of the<figref idrefs="f0009">FIG</figref>. The two highlighted records of the first tooth in the upper left and the next tooth in the jaw model after the gap represent the referenced single teeth.

p0053Further improvements are presented and explained below.

p0054Referring to FIG <figref idrefs="f0006">FIG</figref>, <figref idrefs="f0007">6</figref> and <figref idrefs="f0008">7</figref>, Wherein the <figref idrefs="f0006">FIG</figref> A perspective top view and the <figref idrefs="f0007">FIG</figref> and <figref idrefs="f0008">7</figref> Perspective views of the same device, a rotary table 5 is used to separate various measuring heads 8 for individual teeth under the laser measuring arrangement (see FIG <figref idrefs="f0004">FIG</figref>) to transport. This rotary table 5 is equipped with a friction wheel 15 (see FIG<figref idrefs="f0007">FIG</figref>). This friction wheel 15 is fixed by means of a spring plate 24 (see FIG<figref idrefs="f0007">FIG</figref>) Is pressed against the turntable 5 on the face side. This overcomes any wear on a rubber surface or the rubber material of the friction wheel 15.

p0055The position of the rotary switch 5 is determined by means of an encoder disk 28. In the present case, the disc, as a sheet 28 (see FIG<figref idrefs="f0007">FIG</figref>) Has the slot 100 precisely at the locations at which required stop positions lie. The slots 100 are formed by means of a light barrier 33 (see FIG <figref idrefs="f0007">FIG</figref>) Is detected. In a suitable device or method, a control software evaluates the sensor signals and starts / stops the table or plate 5. The turntable 5 contains seven positions / pots for single teeth. If a work contains more than seven preparations / teeth (maximum 14 per jaw is possible), the work can be scanned in 2 batches.

p0056Advantages of the above-described devices:<ul><li>Very cheap manufacturing costs, available everywhere.</li><li>no wear</li><li>rest</li><li>exact positional knowledge</li></ul>

p0057As an alternative to the friction wheel 15, a belt wheel or a toothed belt can also be used.

p0058The state of the art relates to a scanner from the company DCS Forschungs- und Entwicklungs AG, Allschwil, Switzerland, which was first publicly presented at the trade fair IDS Cologne 1999.

p0059The rotary plate 5 was used for the same purpose in this prior art and was externally toothed. The plate was driven by means of a small plastic gear wheel. The path sections / angles of rotation were traversed by a number of traversing steps defined in the software. There was no feedback to the control whether the angle was also maintained. The plate contained 14 pots, which allowed to measure all max. 14 stumps per jaw in a scangang. This prior art has the following disadvantages:<ul><li>External toothing very expensive and extremely badly available</li><li>The small plastic gear was subject to heavy wear</li><li>Running noise</li><li>Missing feedback via the travel position</li><li>The necessary 14 pots (instead of preferably seven) are disproportionately high costs for the unlikely event that there are more than seven contiguous stumps per work; The 14 pots also require very large installation space and determine size and weight.</li></ul>

p0060Further measures can also be used to lower the frame construction. For this purpose, the frame of the device / device is mounted on two guide rods 83 (cf.<figref idrefs="f0004">FIG</figref> and <figref idrefs="f0005">4</figref>). The complete frame of the device thus consists only of two side parts 2 (compare<figref idrefs="f0004">FIG</figref> and <figref idrefs="f0005">4</figref>), The guide rods 83 (cf. <figref idrefs="f0004">FIG</figref> and <figref idrefs="f0005">4</figref>) And an optical disk (<figref idrefs="f0006">FIG</figref>). Inaccuracies caused by the mechanical design of the linear rod guide are compensated by software (eg by means of so-called "look-up tables"). A precision spindle 94 (cf.<figref idrefs="f0004">FIG</figref> and <figref idrefs="f0005">4</figref>) Is mounted on the side of the traverse table on which the laser arrangement is located. Angular errors of the spindle thus have less effect. The advantages of this configuration are low production costs, high precision, significantly lower transport weight and smaller construction.

p0061With regard to the above-described embodiment, in the device known from the company DCS Forschungs- und Entwicklungs AG, Allschwil, Switzerland, ground linear guides with ball cages were used instead of 2 linear rod guides. This required a massive and highly accurate 8-piece frame construction made of solid metal plates. For reasons of space, the drive spindle could only be mounted on the side of the traverse table opposite the laser arrangement, which leads to angular errors with a slight clearance of the spindle.

p0062A further improvement compared to the aforementioned state of the art can be made for the electrical protection of the laser diode. For this purpose, the laser optics, the laser diode and the control electronics for the laser diode are accommodated together in a metal housing. This results in a better protection for the diode, in particular against electrostatic charges from the outside, as well as a rapid exchange during repairs.

p0063The electronics and the diode are arranged separately in the state of the art in the form of the known apparatus of the company DCS Forschungs- und Entwicklungs AG, Allschwil, Switzerland. After removal of the equipment housing, both components are left open, so that the service personnel can touch the parts and thus optically damage them.

p0064Furthermore, improvements in the adjustment of jaw models are possible in comparison to the above-mentioned prior art. In order to be able to adjust the jaw models to be measured optimally to the measuring range, a template 54 (see FIG<figref idrefs="f0006">FIG</figref>). Because there are jaw models with different diameters (eg for children and adults), the jaw model has to be adapted according to the size. For this purpose, for example, three different alignment contours I, II and in FIG. 3 are applied to the transparent plexiglas disc, from which the template 54 is preferably formed, engraved or otherwise suitably applied.

p0065Furthermore, further improvements can be achieved in the case of the rotation of the individual heads, for example in each case 45 °. The turntable 5 (<figref idrefs="f0006">FIG</figref>, <figref idrefs="f0007">6</figref> and <figref idrefs="f0008">7</figref>) Transports the individual pots 8 to the measuring position in front of the friction wheel 15. While the rotary table 5 moves, the frictional contact of the pot 8 with the friction wheel 15 is produced automatically. The innovation is that the friction wheel 15 is made of rubber or at least has a rubber running surface, but the counter wheel 7 is made of solid metal. This has the advantages of a lower price, a simple manufacture and a long service life. In the state of the art according to the device of the firm DCS Forschungs- und Entwicklungs AG, Allschwil, Switzerland, the friction wheel was made of metal and all counter-wheels were covered with O-rings made of rubber. The disadvantages of this are that the O-rings tear after a certain lifetime and the production costs are high.

p0066Another aspect of the invention is described with reference to the <figref idrefs="f0010">FIG</figref> Is explained. Shown are three tooth stumps 101, each consisting of a ground part 101 a and a residual tooth area 101 b. The grinding process is carried out manually by a dentist and forcibly leads to undercuts 102 which, when viewed in the form of a plurality of adjacent individual teeth or their stumps 101, differ in shape, position and size.

p0067On the tooth stumps 101 for the construction of a strutted prosthesis 103, the overall silhouette of which is shown only by way of example with reference to FIG <figref idrefs="f0010">FIG</figref> Shown at the left in FIG. 1, a so-called cap 104 is produced for at least one stub 101, which can be pushed over the stub 101 as a rule in exactly one push-in or plug-on direction according to the arrow E. In this case, it is not possible for the cap 104 to fill the undercuts 102, since it would no longer be possible to push them on. In the case shown in the context of the present exemplary embodiment, three stumps 101 are arranged next to one another and are correspondingly joined to form a bridge by means of three caps 104 in each case by adjacent copings 104 being connected in each case to a web 105.

p0068In the design of the entirety of all the caps 104, an optimum insertion or insertion direction must now be determined, in which the undercuts 102, which can also be displaced, for example, by the oblique position of a stump 101 as viewed in the other stub 101, <figref idrefs="f0010">FIG</figref> At the rightmost stub 101, can be minimized.

p0069This can be performed beforehand by means of the 3D data obtained from the stub 1. For this purpose, a 3D data set is generated by means of scanning according to the invention, as is already described in detail in the present documents, and is used for model calculations for determining the optimum insertion or insertion direction. In this aspect of the method according to the invention, successive different directions of attachment are successively used, and the "dead space", which is caused by the undercuts 102, is determined for the respective results. The optimum insertion direction A is obtained by determining the variant with the smallest "clearance".

p0070In particular, due to an oblique position of a remaining stump 101, but also due to other machining inaccuracies by the dentist, cases can occur in which a cap with respect to a residual tooth region 101 b in places would have to have a wall thickness of 0 mm. In such a case, basically no prosthesis can be produced. For the further procedure first and time-consuming reworkings of a corresponding tooth stump 101 have to be carried out, this work not being surely leading to a useful result.

p0071In addition to the optimization of the insertion direction E according to the invention for minimizing the undercuts or "dead spaces" 102, the present invention can be used to further improve the procedure for the production of dental prostheses. By means of the acquired (scanned) 3D data, recommendations can be made for the treating dentist through which post-processing of the stumps can be achieved an improvement in the fit and stability of the prosthesis to be produced, including a clear reduction in the undercuts or "dead spaces" 102. For this purpose, the method according to the invention is extended in such a way that, with respect to a detected 3D data set from a tooth stump 101 or in combination with a plurality of tooth stumps 101, an optimum direction of attachment for caps 104, in particular a connection of several caps 104 to a bridge 106, Is that shape changes are possible on the tooth stump / teeth stumps 101. The method and system according to the invention thus not only serves to determine an adaptation to given circumstances for the manufacture and insertion of caps 104 or bridges 106, but also to alter the given circumstances in order to improve the result, ie the prosthesis optimize. For example, the method and system may include providing a graphic display of the stumps including, for example, specially colored areas for post-processing, which serves as a basis for a dialogue between a dental laboratory and a dentist.

p0072By means of the invention in its above-described embodiments, the possibility for a quality assurance is provided in advantageous manner, including, in particular, clear assignments of treatment results to the dentist which grinds the stumps or to the dental laboratory which produces the caps / crowns / bridges. Disputes about inaccuracies can thus be clarified for the first time. Advantageously, it can also be used in this case that all initial data, as well as data from between states, can be archived without any gaps to a particularly simple catfish and can be re-accessed at any time.

p0073The above described with reference to FIGS <figref idrefs="f0010">FIG</figref> And their variants is equivalent to appropriately designed devices by means of which these methods can be carried out, so that also those devices which are readily immediately apparent to the person skilled in the art by means of the representations of the methods in their general and specific forms are described in the present disclosure Documents.

p0074A further aspect of the present invention relates to the automatic generation of the occlusal surface of a dental prosthesis, taking into account the opposite bite (upper jaw to lower jaw). In the embodiment shown in FIGS<figref idrefs="f0010">11 and 12</figref> The following steps are provided:<ol><li>1. Insertion and adjustment of upper and lower jaw 206 or 207 into a chewing stimulator or articulator 200 with adjustment joints 201 until the bis situation is simulated, according to FIG <figref idrefs="f0010">FIG</figref>. The receptacles 202 / 202a and 203 / 203a of the upper and lower jaws 206 and 207, respectively, have a detectable spatial position. For this purpose, the receptacles 202 / 202a and 203 / 203a, for example, each have a defined zero position or a zero position relative to one another. Each receptacle 202 / 202a and 203 / 203a is of a second type, each consisting of a receptacle base 202a and 203a fixedly mounted on the articulator 200, and a jaw holder 202 and 203, respectively, to which the upper jaw 206 and lower jaw 207, respectively, are attached.</li><li>2. Reading / recording of, for example, 6 degrees of freedom:<ul><li>2 options:<ul><li>Manually reading a scale</li><li>Readout of measuring gauges</li></ul></li></ul>With the articulator 200, the optimal / correct position of the receptacles 202 / 202a and 203 / 203a, that is to say actually the respective receptacle base 202a or 203a, is determined, taking account of the upper and lower jaw 206 or 207, in accordance with FIG <figref idrefs="f0010">FIG</figref>, This can be done automatically on scales (not shown) provided and applied to the articulator 200, or by means of distance and angle sensors (not shown). It should also be noted that the articulator 200 preferably allows an adjustment of the upper and lower jaw 206 or 207 relative to one another in preferably six degrees of freedom.</li><li>3. Insert the corresponding jaw holder 202 or 203 with the upper jaw model 206 or the lower jaw model 207 into a holder 205 analogously to the receiving bases 202a and 203a of the scanner 204 according to FIG <figref idrefs="f0010">FIG</figref>, The spatial position of the holder 205 being known to the measuring system or the data system of the scanner 204.</li><li>4. Software is then used for referencing.</li><li>5.<ul><li>Suggestion from database for occlusal surface (eg incisor)</li><li>Automatic adaptation of the database model to the counter-current situation</li><li>Find contact points with envelope data</li><li>Collection of retail space and retail rate</li></ul>Alternative: "articulated" jaw-filling by scanning a part of the articulated jaw and then matching upper and lower jaw data with these partial dentures to produce the bis-position. Also, the method described above with reference to FIGS <figref idrefs="f0010">11 and 12</figref> Is to be disclosed as a method and device, since a person skilled in the art can readily recognize suitable devices in a general or specific embodiment by means of the above explanations.</li></ol>