CA2178093A1

CA2178093A1 - Method and device for a product intended to be introduced into the human body, and scanning device for a model of the product

Info

Publication number: CA2178093A1
Application number: CA002178093A
Authority: CA
Inventors: Matts Andersson; Magnus Persson
Original assignee: Individual
Current assignee: Nobel Biocare AB
Priority date: 1994-10-04
Filing date: 1995-10-03
Publication date: 1996-04-11
Also published as: EP0731673B1; AU713223B2; WO1996010371A1; ES2157346T3; SE9403345D0; ATE201579T1; US5938446A; AU3691595A; SE9403345L; JPH09506815A; DE69521115T2; DE69521115D1; SE503498C2; EP0731673A1

Abstract

A dental bridge can be manufactured with the aid of a model (2) which includes preparations (8, 9, 10). The contours of each preparation can be read off by a reading unit. A computer unit traces the said readings. With the aid of a computer program, the computer processes the read-off information in cooperation with an operator so that a construction based on the tracing is obtained. The position of each preparation in the construction is determined by an apparatus which is functionally separate from the scanning unit. This apparatus generates information items which can be related to the positions of the preparations. These information items are run concurrently with the readings from the scanner in the computer, which in this way can indicate the correct mutual positions of the preparations in the construction.

Description

21780~3 TITLE
Method and device for a product intended to be inL ,-luce~
into the human body, and sr~nn;ng device for a model of the product.
5 T~rT~MTr~T ~IELD
The present invention relates to a method ~or manufacturing a product which can be used in the human body, pre~erably a dental bridge, with the aid of a model comprising dif~erent parts, ~or example preparations. The 10 method Uf;~ 8 a 8r~nn;n~ unit by means of which the contours of the parts can be read of f and can be L.~res_.-ted by electrical, pre~erably digital, r.e,reE_..tations. Also ;nr~ od is a computer unit (micro-processor) which op~rat~ with data or in~ormation items 15 which can be related to the representations and which are arranged in ~iles. ~ith the aid of a _ __t~r program, for example of the QD program type, the computer processes the said data in cooperation with an operator in order to cre~te, on a ~ screen, a construction 20 which is based on the read-o~f re~r~D~..tations. The _ lt~r can also provide proc~ inr; information items which r~reE_~t the said construction and which are used in eq~_ t for manu~acturing or Tn-rh;n;ng of the construction, which can in this case be ~ade in the form 25 o~ a blank, for example o~ titanium. The invention also relates to a device for impl t~nr, the s~id method. The invention furth e deals with a device for 8~:~nn;nr;
parts o~ a model, preferably a del in the ~orm o~ a dental bridge or equivalent dental product with parts in 30 the form of one or re preparations, for manufacture of a construction. A digital re~reDL.-tation, obtained as a ~unction of the 8r~nninrJ or reading, of the contour8 Or the parts or preparations i~: obtained from the 8r~nn;
unit and supplied to the computer . Also ~ nrl ~ in the 35 said r~,r, ,r~e"tation are data rrnr~rn;ng the mutual positlons of the parts or the preparations on the model in question. The _ ~ er unit is arranged to create on the scree~, as a functioll of the ~upplied repre~nt3t;~n

2 ~ ~ % ~ 9 3 ~ ~ P~ 3l and with the aid of a program, for exampl- a ~D program, in cooperation with a user or operator, a construction, for example a de3tal bridge, which is based on the model.
STATE OF T}}E ART
In the manufacture of dental bridges, ~or exa~lLple, it is already known to use a 8r~nn~nr, unit ard computer for 5imulating a construction ba8ed o~ the 8-~nn;~rJ. The computer can also, i3 a known case, calculate ~-rh~n~nrJ coordinates for production of the constructiosl i~ question.
DESCRIPTION OF ThE lNV ~ lUN
INl~:AB PROBLE!
There i8 a need to be able to produce dental bridges, for instance, in a relatively terhn;r~lly simple and computerized manner. In this case it is i __ L---.t to be able to indicate correctly not only the dif ~erent shapes of the dental bridges, but also the r~l~finnnh;r between the parts, at the same time as an e.~L~,~rlat~ and rapid 8r~nn~n,r, function can be used. The inve~tion solves this problem, among others.
In the manufacture of dental products, it has been found to be advantageous to use a sr~nn;n~ unit ln which the reading function (the beam, needle, etc) is directed r~hl; q -~ly to the axis of the respective dental bridge part, at the same time as the dental bridge part is rotated ~bout its said axis. In this way it is possible to operate in the polar co~r~;n~tA~ system, which reduces reading times , data quantities , etc ., despite which ~ _ 1; c~ ted contours can also be read of f .
llowever, there is a clear problem in combinir~g such a tracer principle with _t~.r-aided constructior in accordance with thQ above. The irve3tion solves this problem too.
It is; ___L~t that eq~i_ t known per se, such as ~r~nn;n~ apparatuses, computers, ~ r p ~
etc ., can be used. Thus, ror example, it is adv~ln~g~
if standard sof tware can b-- used . The invention also 2l7sn~3 Wo 96/10371 PCT/SE95/01131 solves this problem and permits the use of CAD pL~.y~
which are known per se for producing the construction.
~OL~ION
The feature which can pr;n-;rAl 1y be regarded as 5 char~cterizing a method according to the invention is that the position of the respective preparation in the construction is detorm; no,d using an apparatus or levelling apparatus which operates separately from the a~-~nn;ns unit, at le~st from the functional point of lO view. The apparatus generates information items which can be related to the positions of the preparations and which are run c~ ..tly with or transform the read-of f Lc~L~c.-tations ~the files) in the computer, which in this way can indicate the mutual positions of the 15 preparations in the construction which is being made on the __to~ screen and is then used for manufacturing the dental bridge.
In a preferred ' '; , use is made of a suF~port plane or a levelling platform on which the model 20 can be arranged and can be ~;~p~co~ in the plane 80 that the preparations can be moved or adjusted to a vertical position. The platform or plane can be turned about two axes, which extend through the plane and are at right angles to one another, in order to provide, in each 25 reading position, a vertical position for the preparation in the model such that the 8~ ~nn~n~ unit which traces the contour of the respective preparation can read of f the whole contour, without there being any ~de~ .L8 or areas n nn~o~led from the 8r~nn;n~ unit. The adjustments of the 30 model in relation to the plane, i.e. the position of the model in the X and Z directions and the inclination of the plane or platform in the rcspective reading position, are detected and indicated by ~T';_ t.. The detected information items are thereafter transferred to the 35 c __~o unit which uses the information in question for the said ~:u..~ c ~ t =ing . The inf ormation f rom the eq-.;F t ig also arranged in files which can be run concurrently in the _--~ oSr';. t.

2l7sn33 Wo 96/10371 r~ 131 ~ urther ' ~ o~ the novel mQthod clre vidert from the att~ched s~hrl~;m~ relating to the method .
The feature which can pr;nr;r~lly be regarded as 5 characterizing tho novel device for impl t~n~ the said method i8 evident from the characterizing clause of ~ttached Patent Claim 8.
A device for 8~nn;n~ a model can be regarded as being characterized in that a support member, _or example 10 a levelling platf orm, is a ~ _d to support the model, which can be activated on a tlacuna~ relative plano, i.e.
either the del is ~ ~pl--ed relative to the plane or the pl~ne i8 tliRplJ~c~tl with the model fixed, 60 that the prepar~tions can assume one or more reading poaitions.
15 The support plane or the levQlling platf orm i8 arranged such that it c~m be turned or tilted 80 that the re~pective preparation can be allocated a d~sired position in the vertical direction. By mean~ cf this ad~ustability in the vertical direction, the contour o_0 the respective preparation can be m~de ~ n~ to the nn~n~ principle which ia uged in conjunction with the invention. The po~3ition o_ the model in the X, Z plane, and the inclinations of the plane or the platf orm in the respective positions, are r--ad o_f by means of e~;_ t 25 which gener~tes inform tion for the ~ _ t~ c~ n;n7 the said a-lJ .~; t~ of model and plane/plat_orm. The inf~ ion can, upon ~ Cl~t;t~n or proc~ ;n~ in the _ ~, and upon the interaction with an operator, r_~ L..t the positions of the preparationa in the 30 construction formed on the ~ _ t e~ screen. In one ~ ' -'; t, the formed construction is sectioned upon production of r'~~'hin~n~J coordinates.
ADVANTAGES
By me~ns of what has been ~ ~.~osad above, 35 reading eq~, t which is }ulown at present can bQ used ~or inputting basic data _or con~truction o~ bridg-s in a ~ er. By mean~ of the invention, ~ t is po~ e for dllta describing the positions o_ the individual 2178093 ~

preparation3 relative to one another to be collected along the 8~ 9nn;n~ function.
DES~ LlUN OF TIIE FIGURES
A presently p ~03~d method and device according 5 to the invention will be described hereinbelow, at the same time with reference to the attached drawings in which:
Figures 1 - 7 3how 8~rc^~ive manufacturing stage3 for production of a construction unit based l 0 on a model, and Figure 8 shows, in circuit diagram form, proce88ing ~tation3 included in plOC~.'317 n~ eg~;, t according to the invention .
Dr!T~Tr.r~!n ~ Tr- , In Figure l, reference number l indicates a plane which can consist of a support platform of a levelling apparatu3 known per se. A model 2 is applied on the platform. The plane or the platform has an axis 3 which 2 0 extends at right angle3 to the plane l . The axis 3 represents a reading position. The model is ,1; ~p~ hly arranged on the platform in the direction~ of the arrowE~
4, 5. The platform operates with two axea which are at right angles to one another and which are here designated 25 as the X and Z axes. The plane or the platform l can be turned about the said axe3 in the directions of the arrowa 6 and 7. The model 2 ;n~ a number of prepara-tions 8, 9, l0, etc. The model can alternatively be fixed in the platform l in a manner known per se, in which case 30 the platform in turn can be ~ pl~ hle in the directions of the arrow~ 4 and 5. In this way, each preparation can be brought one at a time into line with the reading position which is L.~les~ted by the line 3.
Equipment ll is in this case a ~çl~d to trace the X and 35 Z positions as well as the current angles of rotation of the axes 6 and 7. The tracing can be effected in a manner known per se.

217~0~3 WO 96/10371 r~ 1131 ~ 6;
In Figure 2, the model 2 haa been displaced with - the aid of the platform l 50 that the axin 12 o~ the prcparation 8 co~ with the axis 3 which rG~Le= ts the trncer po5ition. Thi5 movement of the platform is 5 lndicated by tracer signals il and i2 in Figure l, which tracer sign~ls ~re lnput to the tracer equipment ll.
The nGxt stage is to orient the prepar~tion 8 in the vertical direction. According to Figure l, the prepnration is tn~l ;n-~d in relation to the axis 3 by an 10 angle gamma. This ;n~l;nnl;~n canmean that u d~_ ~uLs nd certain arens are ~n~ sihle for thQ sr~nn~ns which is e~fected in the 8~h8e~nnt operational 8tep. There is therefore a noed to carry out the said str~h~n~ns of the preparation 8. In accordance with Figure 3, this i8 lS done by the plane l being turned about the axGs X ~nd Z.
In this way, the axis 12 of the preparation 8 can be made to ~o~ n~ e fully with the axis 3 or to ~oi n~
essentially with this axis. These changes in the ~ngle of rotation of the axes are ..~Le3~ ted in Figure l by 20 signals i3 and i4. The8e signals too ~re l~col~d in the tracer ^ql~, t ll.
In accordance with Figure 4, the preparation 8 can be provided with a handle 13 or othQr gripping member, with which the pr^p~n~ n can be transferred to 25 a ~canning unit according to Figure 5. The s~-~nnin~ unit too has a rot~ting platform 14 on which the preparntion 8 can be applied or fixed in a defined position. The 8~nn;ng npparatus is of the type which h~s a tracer function 15 in the form of a needle, optical tracor, etc.
30 A rot~tion ~rrow for the 5aid platform 14 is indicated by 16. The longitudinal axis of the tracer member or tracer ~unction is indicated by 17. The tracer apparatus is charncterized by the fact that the platform 14 is rotated, at the same time as the tracer member 15 and the 35 preparation 8 move reciprocally in the verticAl direction 18. Either the platform can be s~t;~n~ry in the vertical direction and the tracer function can move in th~
vertical direction, or vice versa. Alternatively, both the platform ~nd the tracer function can be vertically 217~
Wo 96110371 PCT/SE95101131 r~ Ahle. The handle can be removed during this tracing operation. The attAchment of the handle 13 can also be made on a part of the preparation which will not be traced by the ~I-Ann;n~ equipment, which means that the handle is not in the way.
Figure 6 shows a computer screen l9 of a computer which is known per se and which is used in this connection. The preparations forming part of the bridge or equivalent are trAn~ ~ ' on the basis of the read-of f data which i5 input to a random QD progr_m . On the 3aid preparation8, a bridge will be constructed in accordance with Figure 7. The construction ~ ~,c~
takea place in a manner known per se by interaction between the _ _t e~ and a user or operator. In Figure 7, a bridge produced on the preparations 8 ', 9 ' and lO ' is indicated by 20. The bridge i5 constructed and Electioned in the computer. The parts are then transformed back 80 that the milling takes place about the axis of rotation 14a which is u~ed during the reading-of f .
Figure 8 shows the entire chain of production.
The levelling function ~ ';h~'~ above is c21rried out at a first station. The said 8rAnn;n~ function takes plaoe at a second atation 22. The axis of rotation i5 indicated by 14a'. The reference labela in other respecta correspond to those which are used in Figure 5, but with a prime symbol added. The digital representation which is obtained ~rom the 8~ -nn;n~ function is shown by 23 in Figure 8. The ~ __~ used in this oonnection is arranged at a ~tation 24 and functions in accordance with the above. The computer is provided with a t~;nAl 25 for the said interaction with a uaer. lU^~h;n;n5 or milling information is indicated by 26, and ~~ h;n;n~
equipment by 27. The ~ ;n;n~ from a blank 28 also takes place in the polar coordinates system. A tool 29 is indicated in principle and ~y ' =l; --~ a milling cutter or other tool. The blank is rotated about a vertical axis 30 . The axis 31 of the tool i~3 ~nr~l ;n~d~ in relation to the axia 32 o~ the blank, by an angle beta. In a preferred . '; ~, the angle beta is the same size as ~ 7~3 W096/10371 PCI/SE9~/01131 the angle ~lph~ and ~lpha~. Tho levellin~ ~Tlt t ha~
the effect that thc ~ t~ can be fed information which can relate to the aaid signals il, i2, i3 nnd i4, which information constitutes digital information 23 ' . The 5 last--- ti~ d information i5 .~ yed too in _ilos in association with the computer. The dataii~n the iles for the information 23, 23' is run c."~ ..tly and is used by the computer for producing the construction on the computer screen.
Since the reading-off function can read off only one preparation at a time, the data describing the mutual rela~ n~h~r between the preparationa must therefore be collectea in another app~ratus in a.c~ .l~..ce with the ~bove. This is called a levelling apparatus according to the above, since the rows of teeth can be strs-;~ht-~nF~
both as regards angle and translation.
Collection of the aata which is required can be carried out ln the fo~ "g way:
1. The preparation in gue~ttion is tr~n~ ted in the X
and Z directions ~to that it is placcd in the "read-off position" on the levelling platform.
2. The preparation is str~ ht~ned by means of the platf orm being rotated about the X and Z axes 80 that it can be read off without any underCuts or the like arising.

3. The position of the prep~ration in the X and Z
directions ana also the angles about the X and Z
axes are read o_f.

4. A "handle" is secured on the preparation. With the ~id o~ the "handle", the preparation c~n be transferred easily to the reaaing-o~f function. The preparation is then read of f in a known manner .
The data which ha8 been read off in thQ levelling apparatua is now used for transforming the read-off filen 3~ 80 that they can be 8een in their correct position8 in a random CAD program. The bridge can then be constructea in the CAD program using the input preparations as basis.

Wo 96110371 r~"~ 1131 _ g _ The bridge constructed in the QD program is sectioned in the ~ and is tr~nn~ ' back ao that the production b~sis for the inner shapes of the included parts iB milled about the centre of rotation with which

5 they were read off. l~at is to ~ay, the read-off file functions as production basis in the same way as ~or single crowns. This is to ensure that the ~n~frl~ will not h~ve an adver3e effect on the accuracy. The accuracy requirements are lower aa regards the outer shapes, which 10 are thus those which are trans~ormed.
The bridge p~rt~ are thereafter joined together in the usual way, by la~er welding 33 in a known manner.
The invention is not limited to the ~ '; t which is shown hereinabove by way of example, but instead 15 can be the subject of '~fl~ations falling within the scope of the attached patent claims and the inventive concept .

Claims

PATENT CLAIMS

1. Method for manufacturing a product which can be used in the human body, preferably a dental bridge, with the aid of a model comprising different parts, for example preparations, and utilizing a scanning unit by means of which the contours of the parts can be read off and can be represented by electrical (digital) representations, and a computer unit which operates with data/information items which can be related to the representations and which are arranged in files, and with the aid of a computer program, for example a CAD program, processes the said data in cooperation with an operator in order to represent, on a computer screen, a construc-tion which is based on the read-off representations, processing information representing the said construction being obtained from the computer unit for use in equip-ment for manufacturing the construction, characterized in that the position of the respective part/preparation in the construction is determined using an apparatus which is functionally separate from the scanning unit and which generates information items which can be related to the positions of the parts/preparations, and in that the last-mentioned information items are run concurrently with the read-off representations in the computer, which in this way can indicate the mutual positions of the parts/preparations in the construction.

2. Method according to Patent Claim 1, characterized in that the model is applied on a support plane included in the said apparatus, for example on a levelling platform, in that the said parts/preparations are brought one at a time to one or more reading-off positions on the plane, in that the plane is turned about two axes, which extend through the plane and are at right angles to one another, in order to provide for the respective part/preparation, in each reading position, a vertical position in relation to the scanning unit so that the latter is able to read off the whole contour of the respective part/preparation, and in that information on the position of the model on the plane and the said angles of rotation about the said axes is supplied and is used by the computer, together with the read-off representations, in order to determine the correct mutual positions of the parts/preparations in the construction.

3. Method according to Patent Claim 1 or 2, characterized in that the respective part/preparation is provided with a handle or equivalent holding member, by means of which the preparation is transferred to the scanning unit for tracing of the contour of the part/preparation.

4. Method according to Patent Claim 1, characterized in that the scanning unit operates with a reading-off function along an axis which is inclined in relation to the axis of the part/preparation, and in that the part/preparation is rotated about its axis during the reading-off, at the same time as the part/preparation and/or the scanning unit (its reading-off axis) moves in the vertical direction.

5. Method according to any one of the preceding patent claims, characterized in that the construction produced using the program is sectioned in the computer, and in that the machining information includes information on the structure of the sections and their mutual positions/locations.

6. Method according to any one of the preceding patent claims, characterized in that the machining/
milling is carried out in a similar way to the tracing for the preparation of the respective section/part, and each read-off file can serve as production basis in the same way as in manufacture of individual parts/dental crowns, etc.

7. Method according to any one of the preceding patent claims, characterized in that the sections or the bridge parts are joined together by means of laser welding.

8. Device for manufacturing a product which can be used in the human body, preferably a dental bridge, with the aid of a model comprising different parts, for example preparations, and utilizing a scanning unit by means of which the contours of the parts can be read off and can be represented by electrical (digital) representations, and a computer unit which operates with data/information items which can be related to the representations and which are arranged in files, and with the aid of a computer program, for example a CAD program, processes the said data in cooperation with an operator in order to represent, on a computer screen, a construc-tion which is based on the read-off representations, processing information representing the said construction being output from the computer for use in equipment for manufacturing the construction, characterized in that a support plane, for example on a levelling platform, is arranged to support the model so that the latter can be displaced to one or more reading-off positions, in that the support plane is arranged such that it can be turned about two axes, which extend through the plane and are at right angles to one another, in order to provide one or more reading positions for the respective part/
preparation in relation to the scanning unit, so that the latter is able to read off the whole contour of the respective part/preparation, and in that information on the position of the model on the plane and the current angles of rotation about the said axes can be supplied and can be used by the computer, together with the read-off representations, in order to determine the correct mutual positions of the parts/preparations in the con-struction.

9. Device for scanning parts of a model, preferably a model of a dental bridge with one or more preparations, for manufacturing the constructions, in which a digital representation, obtained as a function of the reading, both of the contours of the parts/preparations and also of the mutual positions between the parts and the prep-arations is supplied to a computer unit which is arranged to create on the screen, as a function of the supplied representation and with the aid of a program, for example a CAD program, in cooperation with a user or operator, a construction/dental bridge which is based on the model, characterized in that a support member, for example on a levelling platform, supports the model, which can be activated on or with the plane so that each part/
preparation can be brought one at a time to one or more reading-off positions, in that the support plane can be turned about two axes, which extend through the plane, in order to permit adjustment the respective part/
preparation set in the respective tracing position, so that its contour can be read off from a scanning unit, and in that the said representation supplied to the computer includes information derived or extracted from the respective adjustment in the respective tracing position of the position of the part/preparation on the plane and the current angles of rotation of the axes, and in that this information, upon execution or processing and upon the said interaction, indicates, as a function of the extracted information, the positions of the parts/preparations in the construction.