System for the Construction of a Dental Prosthesis
20190239988 ยท 2019-08-08
Inventors
- Markus Heinz (Naturns, IT)
- Hans Peter Foser (Balzers, LI)
- Wolfgang Ruess (Schellenberg, LI)
- Thomas Baaske (Grabs, CH)
Cpc classification
A61C13/0004
HUMAN NECESSITIES
A61C13/1016
HUMAN NECESSITIES
A61C13/1006
HUMAN NECESSITIES
A61C13/097
HUMAN NECESSITIES
A61C13/10
HUMAN NECESSITIES
A61C13/01
HUMAN NECESSITIES
A61C13/12
HUMAN NECESSITIES
Y10T29/49567
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
International classification
A61C13/12
HUMAN NECESSITIES
A61C13/01
HUMAN NECESSITIES
A61C13/097
HUMAN NECESSITIES
A61C19/045
HUMAN NECESSITIES
Abstract
Method and system for the construction of a total dental prosthesis, wherein the shapes of the upper and lower jaw bases taken in the plastic material are digitized and stored as a digital prosthesis model in a data-processing device, and the upper and lower jaw prosthesis bases are produced from dental materials according to the digital prosthesis model by ablative or constructive methods.
Claims
1. A system for the construction of a total dental prosthesis, comprising an upper, lower or set of upper and lower standard front dental arch(es) (40), one or more standard impression tray(s) (2, 4) or individualized impression tray(s) (12, 14) for taking shapes of the upper and/or lower jaw bases with plastic material, a fastening means for fastening the upper, lower or set of upper and lower standard front dental arch(es) to the one or more standard or individualized impression trays, a scanner for scanning an impression of the upper, lower or upper and lower jaw bases, a memory for storing the scanned impression as a digital prosthesis model, and a manufacturing apparatus for producing the upper and/or lower jaw prosthesis bases from dental materials according to the digital prosthesis model.
2. The system for the construction of a total dental prosthesis according to claim 1, further comprising a bite fork (22) for acquiring the position of an occlusal plane by alignment parallel to a bipupillar line and a Camper plane when taking the shapes of the upper and lower jaw bases, and wherein the memory is further configured for storing the digitized position of the occlusal plane relative to the upper and lower jaw bases, wherein the manufacturing apparatus produces the upper and lower jaw prosthesis bases by ablative or constructive methods under the control of a data-processing device.
3. The system for the construction of a total dental prosthesis according to claim 2, wherein the scanner is configured to digitize and store impressions of the upper and lower jaw bases in order to form a starting point for the digital prosthesis model to provide scanned data.
4. The system for the construction of a total dental prosthesis according to claim 3, comprising a database which contains digital standard front dental arch shape data (41) for all standard front dental arches, wherein the data-processing device is configured to retrieve the standard front dental arch shape data, and wherein the data-processing device is configured to integrate the retrieved standard front dental arch shape data with the scanned data of impressions to provide a digital prosthesis model.
5. A system according to claim 4, wherein the data-processing device is configured to retrieve a matching antagonist standard front dental arch from the database in the form of digital antagonist standard front dental arch shape data (42) and combine it with the data of the digital prosthesis model, in such a way that an optimal match with the selected standard front dental arch is achieved.
6. A system according to claim 5, wherein the data-processing device is configured, after integration of the standard front dental arch shape data (41) and optionally antagonist standard front dental arch shape data (42) into the digital prosthesis model, to offer one or more premolar tooth rows matching the selected standard front dental arch for selection and, after selection, wherein the data-processing device is configured to retrieve premolar tooth row shape data (44) and enter the premolar tooth row shape data (44) into the digital prosthesis model.
7. A system according to claim 6, wherein the data-processing device is configured to generate a graphical representation of the digital prosthesis model on a display and to provide a digital wax knife as a program function, in order to allow a user to design the gum and the prosthesis base surfaces with the digital wax knife in the graphical representation of the digital prosthesis model, and to transfer the configurations carried out into the digital prosthesis model.
8. A system according to claim 7, wherein the data-processing device is configured to provide a multiplicity of predetermined surface textures for selection, and to make the surface textures applicable to selected regions of the surfaces of the digital prosthesis model and transfer them into the digital prosthesis model.
9. A system according to claim 8 wherein the data-processing device is configured to retrieve at least one gingiva parameter for specification, to which at least one of the following gingiva parameters belongs: gingival frame of the tooth lengths of the installed teeth, minimum wall thickness of upper and lower jaw bases, surface texture parameters of the palate surface and geometrical parameters of the transition region from the prosthesis body to the tooth, wherein the data-processing device is configured to transfer entered gingiva parameters into the digital prosthesis model.
10. A system according to claim 9, wherein the data-processing device is configured to call up at least one tooth cavity parameter for specification, to which a width of an adhesive gap between an inner wall of the tooth cavity and an inserted tooth base and the position and number of spacers on the inner wall of the tooth cavity for defined positioning of the base of the inserted tooth with a uniformly wide adhesive gap relative to the inner surfaces of the tooth cavity belong, and to transfer the specified tooth cavity parameters for all tooth cavities into the digital prosthesis model.
11. A system according to claim 10, wherein the data-processing device is configured, when, during the calculation of the cavities for prefabricated plastic teeth, it is established that the remaining wall thickness of the prosthesis base below the cavity would fall below a predetermined minimum wall thickness, to store the length to which the plastic tooth is to be reduced in order to comply with the predetermined minimum wall thickness below the cavity, to adapt the cavity to the reduced length of the plastic tooth and to store it in the digital prosthesis model, and to control a milling device in such a way that the prefabricated plastic tooth is shortened to the stored reduced length of the plastic tooth.
12. A system according to claim 11, wherein the data-processing device is configured to provide a selection menu for artificial teeth made of different materials, in which a material selection from dental materials is possible for each tooth position, the data-processing device being configured to take the selected material type into account during the calculation of the cavities in the prosthesis bases, in order in each case to obtain an optimally dimensioned adhesive gap for the respective material type.
13. A system according to claim 12, wherein the bite fork (22) has an inner bite arch (24) and an outer arch (26) applied thereon using articulations, the articulations being provided with scales (30) so that, after turning the outer arch into alignment parallel to the Camper plane and parallel to the bipupillar line, the resulting deviation of the parallelism of the inner bite arch from that of the aligned outer arch can be read from the scales on the articulations.
Description
[0043] The invention will be described below with the aid of an exemplary embodiment in the figures, in which:
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[0076] The production of a dental prosthesis using a method and system according to the invention, in which individualized impression trays are used, will first be explained below.
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[0078] These shapes of the upper and lower jaw bases which have been taken are scanned in a sampling apparatus 8 represented in
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[0080] On the basis of the digital prosthesis model thus initially obtained, in a CAD/CAM-controlled manufacturing apparatus, as represented in
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[0084] The set of standard front dental arches may, for example, contain front dental arches with different front tooth sizes (small/medium/large) and different front dental arch sizes (wide/medium/narrow). Each standard front dental arch may, for example, comprise six front teeth.
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[0086] If deviations from the zero position of the scales were registered during the position determination of the occlusal plane, the deviating values are to be entered into the data-processing device. The position of the occlusal plane is adapted according to the specifications.
[0087] The further construction and refinement of the digital prosthesis model then takes place in the data-processing device, which delivers a display of the spatial digital prosthesis model, as schematically shown in
[0088] For the physically selected standard front dental arch, the identification of which is entered into the data-processing device, a data set of digital standard front dental arch shape data for the selected standard front dental arch is then called up by the data-processing device from a database. This digital model of the selected standard front dental arch is then integrated into the digital prosthesis model in such a way that the position of the digital model of standard front dental arch shape data which has been called up relative to the digitized jaw base data matches as well as possible the position of the scanned data of the standard front dental arch fastened on the impression tray in the digital prosthesis model. This is indicated in
[0089] The data-processing device is then furthermore adapted to call up an antagonist standard front dental arch, which matches the selected standard front dental arch, from the database of the digital models for the standard front dental arches. If a plurality of antagonist front dental arches in the database are declared potentially suitable for the selected standard front dental arch, these are shown for selection by the data-processing device. Subsequently, the digital model data of the selected antagonist standard front dental arch 42 are combined with the digitized data of the digital prosthesis model of the associated jaw base, in such a way that an optimal setting/position with the already previously selected digital data of the selected standard front dental arch 41, which have been integrated into the digital prosthesis model, is achieved. This is represented in
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[0091] Thus, the tooth data of all teeth are successively entered in their position into the digital prosthesis. A functional check of the positioning is carried out with the digital articulator. The data-processing device is in this case adapted to detect and store functional contact defects in the occlusion and in the occlusion movement. Contact defects can subsequently be removed by the user using grinding technology.
[0092] As shown in
[0093] Furthermore, a multiplicity of predetermined surface textures are provided by the data-processing device for selection, which the user can select and apply to selected regions of the surfaces of the digital prosthesis model, after which they are transferred into the digital prosthesis model.
[0094] For further configuration of the gingiva, a number of gingiva parameters are offered by the data-processing device to the user for specification. These include:
[0095] 1. gingival frame of the tooth lengths of the installed teeth, i.e. the depth of the cavity which receives the tooth base in the jaw base,
[0096] 2. minimum wall thickness of upper and lower jaw bases, i.e. the minimum thickness of the wall thickness of the base remaining below a cavity,
[0097] 3. surface texture parameters of the palate surface, and
[0098] 4. geometrical parameters of the transition region from the prosthesis base body to the tooth in the cavity. With the latter geometrical parameters, the user can configure the transition region from the prosthesis base surface to a cavity, and may for example provide rounding.
[0099] By rounding or chamfering on the upper edge, the cavity is widened slightly on the upper edge. This creates a slightly widened edge around the tooth base in the transition region to the prosthesis base surface, this widened transition region being filled with adhesive when adhesive bonding of the artificial teeth. When antibacterial additives are used in the adhesives, improved protection against ingress or establishment of bacteria in the transition region of the tooth base and tooth cavity of the prosthesis base can thus be ensured.
[0100] It is necessary to take into account and comply with a minimum wall thickness of the upper and lower jaw bases in the region of the cavities in order to ensure a minimum strength of the prosthesis base body in the region of the cavities as well.
[0101] Furthermore, tooth cavity parameters are called up by the data-processing device for specification by the user. These include positioning, number and size of spacers 124 in a cavity 120, as shown in
[0102] When, during the calculation of the cavities, it is established in the data-processing device that the remaining wall thickness of the prosthesis base below the cavity would fall below the predetermined minimum wall thickness, for the artificial tooth provided for said cavity the data-processing device stores a shortened length such that the predetermined minimum wall thickness below the cavity is maintained. In the case of using prefabricated plastic teeth, the prefabricated plastic tooth length to be shortened is then used to control an automatic milling apparatus, into which the prefabricated plastic tooth is inserted and is shortened to the shortened length. This process is schematically shown in
[0103] After all the data and parameters in the digital prosthesis model have been specified and established, the data-processing device controls a CAD/CAM-controlled manufacturing machine in accordance with this digital prosthesis model, for example a milling machine in which the designed prosthesis base body is produced from a block consisting of gum-coloured plastic material by an ablative method, the processing of the prosthesis base body with an automatically controlled miller being shown in
[0104] Subsequently, the prosthetic teeth are adhesively bonded into the cavities of the manufactured prosthesis base bodies by means of a joining medium, as shown in
[0105] In order to adhesively bond the artificial teeth permanently in the cavities, correct positioning is necessary. In this case, each tooth or each tooth group is to be checked individually and manually onto the correct recess in the cavity and subsequently adhesively bonded. As the checking instrument, a transfer template is to be used, which may additionally be used as a transfer instrument when adhesively bonding the individual teeth and/or tooth row. This transfer template is a negative mould of the tooth group, produced by a CAD/CAM manufacturing machine. Reliable and correct positioning is thus ensured. The teeth and/or tooth groups are positioned in the template and transferred into the cavities of the prosthesis base body during the adhesive bonding. The final polishing is carried out conventionally on a polishing unit. The prosthesis base bodies must be smooth and free of burrs, and the prosthesis edges are to be processed round and never with sharp edges.
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[0109] As shown in
[0110] As shown in
[0111] As shown in
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[0113] The individual position of the registering articulation is digitized by scanning. The placement position of the patient's upper and lower jaw bases can be reproduced individually in the virtual articulator.
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[0115] As an alternative, the entire trial prosthesis (prosthesis base body including prosthetic teeth) may be manufactured in one piece.
[0116] The functional and aesthetic check of the trial prosthesis is carried out in the patient's mouth.
[0117] After the trial, optionally correction of the tooth position/placement and optionally new digitization in the sampling device and storage of the modified situation in the data-processing device are carried out.
[0118] After the correction, the permanent dental prosthesis or a further trial body may be manufactured.
[0119] In a CAD/CAM manufacturing machine controlled by the data-processing device, the artificial teeth are manufactured in accordance with the digital prosthesis model by ablative or constructive methods, an ablative method being illustrated in
[0120] The gingiva parameters defined in the data-processing device are taken into account automatically during the manufacture of the prosthetic teeth. Retrospective reduction of the tooth lengths is not necessary in this method.
LIST OF REFERENCES
[0121] 2, 4 standard impression tray
[0122] 6 centric tray
[0123] 8 sampling device
[0124] 10 virtual articulator
[0125] 12, 14 individualized impression tray
[0126] 11, 13 pin for attaching registering elements
[0127] 15, 16 holders for inserting registering elements
[0128] 18, 20 registering elements
[0129] 22 bite fork
[0130] 24 inner bite arch
[0131] 26 outer arch
[0132] 28 articulations of the bite fork
[0133] 30 scale of the bite fork
[0134] 40 standard front dental arch
[0135] 41 digital standard front dental arch shape data
[0136] 42 digital antagonist standard front dental arch shape data
[0137] 44 digital premolar tooth row shape data
[0138] 112 lower jaw base in the digital prosthesis model
[0139] 114 upper jaw base in the digital prosthesis model
[0140] 116 gum in the digital prosthesis model
[0141] 120 cavity
[0142] 124 spacer
[0143] 140 artificial tooth
[0144] 142 tooth base