DEVICE, METHOD AND APPLICATION IN CONNECTION WITH A DENTAL PROSTHESIS ARRANGEMENT IN THE JAW

Abstract: A dental prosthesis arrangement incorporates one or more implant(s) (13, 14) and one or more attachment part(s) (8, 9) which can be fitted thereto by a joint. At least a first joint between implant and attachment part, alternatively between attachment parts, consists only of a truncated cone or other conically tapered body which is arranged on the implant or attachment part or on the one attachment part and which is guided or guidable in wedging mechanical interaction with a corresponding recess (6) in the attachment part or implant concerned, and a section (1b) connecting to the said truncated cone or other conically tapered body, which section is bendable in order to achieve a common insertion direction for the dental prosthesis arrangement.

Description: TITLE Device, method and application in connection with a dental prosthesis arrangement in the jaw TECHNICAL FIELD The present invention relates to a device for or in connection with a dental prosthesis arrangement, which comprises one or more implant (s) and one or more attachment part(s), e.g. one or more spacer (s), one or more bridge (s), parts of spacers or bridges, etc., fitted to the said implant (s) by a joint. The invention also relates to a method for realizing a joint in a dental prosthesis which comprises one or more implant (s) and one or more attachment part(s) fitted to the said implant (s). The invention additionally relates to a specific application of a truncated cone arrangement and a recess or recesses corresponding to the said cones . PRIOR ART By virtue of American Patent Application 4 645 453, it is previously known to use cemented joints in dental prostheses which comprise an implant and attachment parts. The patent describes, inter alia, the use of a bendable section by means of which the part or parts supporting the dental prosthesis can be angularly orientated in relation to the slant of the implant in the jawbone . It is also previously known to use an implant with bendable part for its head or upper part. The implant is screwed into the dentine and in the screwed-in position the bendable part is actuated into the desired vertical extension position in relation to the slanted position of the implant in the dentine. Reference can here be made, inter alia, to the K. S . I . -Bauer-Screw system sold on the market, which is supplied by "Keramisches Dental- Labor, GmbH/DE" . It is also previously known to use an implant having conical joints, see, for example, American Patent Application 4 772 204. In this case, the spacing element has a conical section which passes at the bottom into a threaded, cylindrical part. Spacing elements of this type are however not designed to be bent and, because of the threaded part, difficulties arise with the orientation even if bending were to be possible. The spacing elements are therefore impossible to use in combination with angular orientation. ACCOUNT OF THE INVENTION TECHNICAL PROBLEM There is a need in dental contexts to be able to use technically simple and unambiguous components (screws, spacers, bridges, sleeves, etc.) which are easy to combine in dental prosthesis attachments and nevertheless give reliable joints which are durable over a long period in the patient. The invention aims to solve this problem, inter alia. There is also a need to be able to establish temporary dental prosthesis systems which shall be able to be implemented in the jaw or jaws of a patient during the time when patients are undergoing restoration (e.g. extensive restoration) by means of a permanent dental prosthesis system. The invention solves this set of problems also. According to the inventive idea, use is made of the discovery that so-called Morse cones have a high mechanical wedging effect. There is here a need for the cones in question and corresponding recesses to be arranged such that necessary strong mechanical joints are obtained between the components concerned. In addition, the arrangement shall be such that chewing and biting motions " of the patient, and corresponding external effects, reinforce or do not weaken the joint. The invention solves this problem also. In temporary and permanent dental prosthesis systems, there is a need for those parts in the system which support the dental prosthesis to be able to be arranged and angularly orientated such that a common insertion direction for the dental prosthesis is possible despite the fact that an implant has been arranged at a slant in the dentine owing to poor condition of the latter. In case of non-parallelism between two or more spacing elements exceeding the cone angle for the second cone, fitting is impossible in practice. The invention is here of the type which uses a bendable section or bendable zone which, under the influence of bending, can be redirected in relation to the implant screw or implant body. It is in this case important that the bending function can be effected outside the jaw of the patient so that the patient's dentine is not subjected to bending forces which cause discomfort and pain in the patient. Bending of an implant in the patient can lead moreover to the implant breaking loose from its position, especially if it is placed in bone of poor quality, i.e. low-density bone. The invention solves this problem also. In connection with the exercising of the bending function, the attachment parts connected to the implants (spacers, bridges, sleeves, etc.) shall be able to be angularly orientated such that the respective attachment part acquires the correct position extending in the vertical direction (in the direction of the tooth) despite the fact that the bending function is effected outside the mouth of the patient. The invention solves this problem also and proposes a simple method for assessing (pointing out) the angular position, for effecting the bending outside the mouth and for returning the element having the bent zone such that the previous angularly orientated position is obtained. It is also important not to need to use cement or glue in the joint, the biocompatible effects of which have not been established in long-term trials. The invention solves this problem also. THE SOLUTION What can primarily be considered to be characteristic of a device for a dental prosthesis arrangement according to the invention is that at least a first joint between implant and attachment part, here referred to as the first case, alternatively between attachment parts, here referred to as the second case, consists only of a truncated cone or other conically tapered body which is arranged on the implant or attachment part in the first case or on the one attachment part in the second case and which is guided or guidable in wedging mechanical interaction with a corresponding recess in the attachment part or implant in the first case or the second attachment part in the second case. In a preferred embodiment, the implant supporting the truncated cone or the body, or the attachment part supporting the truncated cone or the body, is arranged with a section connecting to the truncated cone or the body, which section is bendable for the achievement of a levelling function in the dental prosthesis arrangement when the implant is arranged at a slant in the dentine. In a preferred embodiment, the bendable section is essentially of uniform thickness and has essentially the same diameter or corresponding measure as the truncated cone or body exhibits at its base or widest end. The truncated cone or body can form part, together with the bendable section, of a threaded implant . The truncated cone or body, here referred to as the first truncated cone or body, forms part, together with the bendable section and second truncated cone or body, of an element in which the first and a second truncated cones are secured in the respective end of the bendable section. The truncated first cone can exhibit a cone angle of 2- 4°, preferably ca. 3°. The second cone can exhibit a cone angle of 6-10°, preferably ca. 8°. The components, in the form of implant and attachment part or attachment parts, provided with truncated cones and recesses, are preferably constructed in titanium or material with high friction coefficient within the range 0.2-0.8, preferably ca. 0.5. A device according to the invention can primarily be considered to be characterized in that the implant or a first attachment part is arranged with a first section designed as a truncated cone or other conically tapered body, in that a second attachment part or the implant is arranged with a recess corresponding to the truncated cone or body, and in that the truncated cone or body and the corresponding recess are arranged to form part of a wedging mechanical interaction which alone, i.e. without cement, glue, etc., realizes the said joint. A method according to the invention can primarily be considered to be characterized in that a truncated cone or other conically tapered body arranged on a first section of an implant or first attachment part is guided in wedging mechanical interaction with a corresponding recess on the first attachment part or the implant or a second attachment part with the aim of attaining a cement-free or glue-free joint. In a preferred embodiment of the method, a second section connected to the first section, when the implant is slanted in the dentine concerned, is assigned bending forces for levelling the upper part of the implant in relation to the slant. Further embodiments of the invention can be ascertained from the following sub- claims . An application of a truncated cone or other conically tapered body and an application corresponding thereto are characterized in that the truncated cone or body which is disposed on an implant forming part of a dental prosthesis arrangement or on a first attachment part, connectable to this, and recess which is disposed on the first attachment part or a second attachment part or the implant is used as a wedging joint which eliminates the need for cement, glue, etc. ADVANTAGES As a result of the above-proposed, the joint for a permanent or temporary dental prosthesis arrangement such as bridges, individual teeth, parts of bridges and teeth, etc., is obtained in simple manner through the use of Morse cones and recesses interacting therewith. In the fitting operation, the work of the dentist is substantially simplified by the fact that he/she can simply identify the rotation angle position for the element, which thereafter can be assigned bending forces outside the mouth and reinserted to an adjusted rotation angle position. The bending force can be assigned using a simple, e.g. tubular, tool. Dimensioning of parts of the element can be carried out such that weakening upon bending is minimal, thereby guaranteeing a durably effective joint, the wedging function of which is additionally reinforced with chewing and biting motions of the patient. Conventional joints with threads, screws and untested glue can be eliminated. The effectiveness of the Morse cone is enhanced by the use of material with high friction coefficients in the two joinable parts . DESCRIPTION OF FIGURES A currently proposed embodiment of a device, method and application of the invention shall be described below with simultaneous reference to the appended drawings, in which Figure 1 shows in vertical view an embodiment of an element which supports at its ends sections designed as truncated cones and which sections are combined with a section which acts as a bending zone, Figure 2 shows in vertical view the element according to Figure 1, but rotated by 90°, Figure 3 shows in end view the element according to Figure 1, Figure 4 shows in vertical view tubular tool parts applied to the element according to Figure 1, which tool parts are used to impart a bending upon the bending zone of the element, Figure 5 shows in vertical view and in basic representation two elements which form part of a mechanical joint between implants screwed into a jaw and attachment part(s) fitted to the implants , and Figures 6-6a show in vertical views and in partial cross section a further embodiment. DETAILED EMBODIMENT In Figure 1, a device or element according to the invention is denoted by 1. In the illustrative embodiment, the device is designed as a pin or column and has first, second and third sections la, lb and lc . The first section has the form of a first truncated cone, the half cone angle α of which is in the order of magnitude of 0.75-3°, preferably ca. 1.5°, i.e. the cone angle 2oc is 1.5-6°, preferably ca. 3°. At its widest part, the first truncated cone is provided with a diameter of 1.5-2.0 mm, preferably ca. 1.8 mm. The tolerance for the diameter is high and in the present case is chosen at 2/100 mm (0.02 mm). The first truncated cone has a length L of 3-5 mm and is preferably ca. 4 mm. The first section la connects at its widest part to a cylindrical second section lb, of a diameter which essentially corresponds to the said diameter D and has a length LI of 2-5 mm, preferably ca. 3 mm. At its end facing away from the section la, the cylindrical section lb passes into the third section lc via a radius R of 0.1-0.3 mm, preferably ca. 0.2 mm. The third section lc has the form of a second truncated cone which exhibits a cone angle β of 6-10°C, preferably ca. 8°, and a diameter Dl at its widest point of 2-4 mm, preferably ca. 3 mm, and the tolerance is here too ca. 2/100 mm. The length L2 is 6-10 mm, preferably ca. 8 mm. The section lc is provided with a straight bevel 2, see also Figures 2 and 3. The surface of the bevel is situated at a distance A from the centre axis 3 of the element. In the illustrated case, the distance is chosen at within the range 1.0-1.4 mm and is preferably 1.2 mm with a tolerance accuracy of 3/100 mm. The total length of the element is preferably ca. 15 mm and the sections are preferably constructed in titanium or equivalent with a friction coefficient of ca. 0.5 mm. According to Figure 4 , the section lb acts as a bending zone. By means of tubular tool parts 4 and 5, a slant γ between the longitudinal axes 3a and 3 ' respectively of the sections la and lc can be simply realized. As a result of the cylindrical form of the section lb, the risks of the element breaking or becoming substantially weakened upon ' bending and during the subsequent application in the mouth of the patient, are averted. In Figure 5, two connecting elements 1' and 1'' are bent in their bending zones lb' ' and lb' ' ' respectively according to Figure 4. The third sections lc ' and lc ' ' are arranged in the recesses 6 and 7 respectively having conical walls 6a and 7a corresponding to the conical forms of the truncated conical form of the third section lc ' and lc ' ' respectively. The recesses 6 and 7 are produced with identical or essentially the same accuracy as the conical form of the first section, so that a high wedging function is present on the part or parts 8, 9 supported by the recesses 6 and 7 , a force F generated upon chewing or biting motions, or by external influence, is present relative to a jaw 10 shown in basic representation. The part or parts 8, 9 can comprise a bridge, sleeve, spacer, etc. or parts thereof . The first sections la' and la' ' are arranged in corresponding manner in recesses 11 and 12 respectively having conical walls 11a, 12a, the conical forms of which essentially correspond to the conical form of the respective first section. The accuracy for the conical forms of the recesses is as large or essentially as large as for the respective conical form for the conical form of the first section, so that here too the mechanical wedging force is strong or exceedingly large, since a force F' generated by external influence and/or by chewing or biting motions arises in the dentine 10 (relative to the force F) . In the illustrated case, the other conical recesses 11 and 12 are arranged in implants 13, 14, which can be constituted by a type which is known per se and which are screwed in place by means of threads 13a, 14a in the dentine 10. The parts 8, 9 and the implants 13, 14 can be constituted in titanium or corresponding material with a high friction coefficient which can be in the order of magnitude of 0.5. The bevels 2 ' , 2 ' ' can form rotation- angle-orientated markings for the dentist or equivalent. In one embodiment, the sections la' and la 1 ' are applied in the recesses 11 and 12 respectively with relatively low friction force F'. Any bending of the zone lb'' and lb' ' ' is assessed and the element(s) 1', 1'' is/are removed and bending effected according to Figure 4 or in some other way. The bevels 2' and 2'' can form part of the angle orientation upon renewed application of the sections la' and la' ' in the recesses 11 and 12 respectively. Following possible further bending adjustments when the described process is repeated, the sections are pressed tight (wedged) in the recesses 11 and 12 in the rotation positions defined by means of the bevels 2 ' , 2 ' ' . The sections lc ' and lc ' ' thereupon assume essentially parallel directions congruent with the vertical direction of the tooth attachment in question. The attachment part or attachment parts 8, 9 can thereafter be pressed onto the sections lc, lc ' ' by way of their recesses 6 and 7. The effected mechanical wedging can be of temporary or permanent nature. Naturally there are cases in which bending of the bending zone does not need to be carried out, in which case the bending operation is omitted. The bevels 2', 2 ' ' can constitute rotation angle fixing in the respective implant 13 , 14 , the implant being constructed with a surface 15 opposed to the bevel, see line in Figure 2. The cone angles 2α and β can be varied and related, e.g. to the friction coefficient in the respective used material . The respective implant or attachment part can be provided with fixedly arranged elements or columns which, at their free ends, are interactable with a corresponding conical recess or recesses in another attachment part or the implant . Known Morse cones can thus be used as a joint between implant and attachment part or attachment parts, or between attachment parts . The respective section constructed as a truncated cone can be replaced by another type of conically tapered body and can have the form, for example, of a truncated pyramid, pentagon or hexagon, etc. The slant of the respective implant in Figure 5 is identified by the fact that the longitudinal axis 3'' for the implant part la' in question is angled in relation to the longitudinal axis for the element part lc ' . The parts lc ' and lc ' ' are arranged such that they are essentially congruent with the direction of insertion of the dental prosthesis or are mutually levelled so that the one element part does not substantially jut above the second element part. The invention is not limited to the embodiment shown by way of example above but can be subject to modifications within the scope of subsequent patent claims and the inventive concept. Thus, for example, according to Figures 6 and 6a, an implant can be constructed having a conical recess 12 ' with a half cone angle of corresponding size (e.g. 1.5°) to the cone angle for la' ' ' (see Figure 1) . A diameter D for the recess 12' falls in line with the size D of the section la' ' ' . The angle and diameter measurements are mutually matched with great accuracy (as is the case for Morse cones) so that sought-after wedging forces are attained when the section la' 1 ' is applied in the recess 12'. The section lc (see Figure 1) can then interact with an attachment part and the bevel 2 can here be used as rotation angle fixing. A device according to the invention can thus also additionally or separately be characterized in that it has the form of an implant which has a conical recess for connection only by means of cones of an attachment part or equivalent to the implant, which cones wedge mechanically one into the other.

Claims: PATENT CLAIMS 1. Device for " a dental prosthesis arrangement, which comprises one or more implant (s) (13, 14) and one or more attachment part(s) (8, 9), e.g. spacer (s) or bridge (s), etc., fitted to the said implant (s) by a joint, characterized in that at least a first joint between implant and attachment part, here referred to as the first case, alternatively between attachment parts, here referred to as the second case, consists only of a truncated cone (la) or other conically tapered body which is arranged on the implant or attachment part in the first case or on the one attachment part in the second case and which is guided or guidable in wedging mechanical interaction with a corresponding recess (6) in the attachment part or implant in the first case or the second attachment part in the second case, the implant supporting the truncated cone or body, or the attachment part (8) supporting the truncated cone or the body, being arranged with a section (lb) connecting to the truncated cone or body, which section is bendable for the achievement of a levelling function in the dental prosthesis arrangement when the implant (13, 14) is arranged at a slant in the dentine, i.e. that longitudinal axis of the implant which is congruent with the longitudinal axis (3'') of the third section is slanted in the dentine. 2. Device according to Patent Claim 1, characterized in that the bendable section (lb) is essentially of uniform thickness in the unbent position and has essentially the same diameter or corresponding measure as the truncated cone or body exhibits at its base or wider end. 3. Device according to Patent Claim 1 or 2 , characterized in that the truncated cone or body forms part, together with the bendable section, of a threaded implant . 4. Device according to Patent Claim 1 or 2 , characterized in that the truncated cone or body, here referred to as the first truncated cone or body, forms part, together with the bendable section and second truncated cone or body, of an element in which the first and second truncated cones or bodies are secured in the respective end of the bendable section. 5. Device according to any of the preceding patent claims, characterized in that the truncated cone exhibits a cone angle of 2-4°, preferably ca. 3°, and/or the second truncated cone or body exhibits a cone angle of 6-10°, preferably ca. 8°. 6. Device according to any one of the preceding patent claims, characterized in that the components, in the form of implant and attachment part or attachment parts, provided with truncated cone or body and recess, consist of titanium or material with high friction coefficient, e.g. friction coefficient of 0.2-0.8, preferably ca. 0.5. 7. Device for effecting a joint in a dental prosthesis arrangement, which comprises one or more implant (s) (13, 14) and one or more attachment part(s) (8, 9) which can be fitted to the said implant (s), characterized in that the respective implant or a first attachment part is arranged with a first section (la) designed as a truncated cone or other conically tapered body, in that a second attachment part or the implant in question is arranged with a recess corresponding to the truncated cone or body, and in that the truncated cone or body and the corresponding recess are arranged to form part of a wedging mechanical interaction which alone, i.e. without cement, glue, etc., realizing the said mechanical joints . 8. Method for realizing a joint in a dental prosthesis which comprises one or more implant (s) and one or more attachment part(s) fitted thereto, e.g. spacer or spacers, bridge or bridges, etc., characterized in that a truncated cone or other conically tapered body arranged on a first section of an implant or first attachment part is guided in wedging mechanical interaction with a corresponding recess on the first attachment part or the implant or a second attachment part with the aim of attaining a cement-free or glue- free joint, a second section (lb) connected to the first section (la) , when the implant is slanted in the dentine (10) concerned, being assigned bending forces for levelling the upper part of the implant in relation to the slant. 9. Method according to Patent Claim 8, characterized in that the truncated cone or body and recess of the first attachment part are guided to interaction with the recess and truncated cone or body respectively of the implant or of the second attachment part in an intermediate position in which the first attachment part is separable from the implant and the second attachment part respectively, in that the first attachment part is separated from the implant and the second attachment part respectively and hence bending forces are assigned to the second section (lb) , and in that the first attachment part once again, following any intermediate adjustments, is guided in interaction with the implant and the second attachment part respectively into essentially the same angularly orientated position. 10. Application of a truncated cone or other conically tapered body and recess corresponding thereto, characterized in that the truncated cone which is disposed in an implant forming part of a dental prosthesis arrangement or on a first attachment part fittable to this, and the recess which is disposed on the first attachment part or a second attachment part or the implant is used as a wedging mechanical joint which eliminates the need for cement, glue, etc., and a section connecting to the said truncated cone or other conically tapered body being bendable in order to achieve a common insertion direction for the dental prosthesis arrangement.

Inventors: HANSSEN HALVAR, HANSSEN, HALVAR
Applicants: HANSSEN HALVAR, NOBEL BIOCARE AB, HANSSEN, HALVAR, NOBEL BIOCARE AB (PUBL)
Application year: 1999
Main classification: A61C8
IPC codes: A61C8