TENSION MATRIX AND TIGHTENING DEVICE FOR ODONTOLOGICAL USE CAPABLE OF BEING INTEGRAL

Abstract: Tension matrix (1) and tightening device (2) are equipped with means of attachment (3, 4, 5) capable of making them integral with one another in a reversible manner. These means may be protruding laminar member (5) that can be slid, which is inserted in groove (3) located on one face of casing (6) of tension matrix (1) and one member with a hook (4) with flat part that engages against the flat surface (6a) of the opposing face of casing (6). The above-mentioned means may be comprised of: shaped groove (40) located on the outer surface of one part (41a) attached to casing (41) of tension matrix (101) and flexible fork (39) ending at each of its two ends with protruding part (39a, 39b) capable of being connected in an integral manner in a reversible way with above-mentioned shaped groove (40) of casing (41) of tension matrix (101) when fork (42) itself is inflected to a pre-determined extent. It is possible to apply the tension matrix and to tighten the relative matrix merely by using the hand that is holding the tightening device.

Description: Tension matrix and tightening device for odontological use capable of being integral The invention relates to the field of devices for the application and the tightening of matrices for dental reconstructions in odontology. Among . such devices, the most advanced to date include a tension matrix comprising a turning pin attached to a casing within which the pin itself pulls the matrix in its rotation, placing it into tension, and a tightening device that can be attached to the above-mentioned pin when the tension matrix is already applied with the relative matrix around the tooth, so as to be capable of making it rotate while tightening the matrix and making it adhere to the outer walls of the tooth itself. An example of device made in this way is provided by U.S. patent 4,396,374, for example. The drawback that is encountered in the use of device of this type is that of the insufficient ease of handling: in fact it is necessary to first apply the tension matrix and the matrix, with the matrix not yet in tension, while manually maintaining in position in the oral cavity, and then to insert the tightening device by attaching it the tension matrix, while still manually holding the matrix, until it has been placed in tension. All this involves significant practical difficulties and a situation of prolonged discomfort for the patient. The inventor of the present invention has attempted SUBSTITUTE SHEET to eliminate this drawback by working out a unit including both a tension matrix and a turnbuckle which can be made integral, so that the matrix can be applied, maintained in the correct position and tightened merely by inserting and subsequently activating the tightening device, which moves with itself the matrix which is integral with it. The object of the invention is thus a unit comprising a tension matrix and a tightening device for use in dentistry composed of a tension matrix including a pin equipped with a slot for the introduction of the ends of the matrix and with a casing also equipped with slot, which holds the pin within itself, and with a tightening device that can be attached to said pin and capable of making the pin rotate, by the fact that the tension matrix and the tightening device are equipped with means of attachment capable of making them integral in a reversible manner. A detailed description of the functioning of the invention as a unit according to some preferred embodiments will now follow, with reference being made to the attached drawings: - figure 1 represents an enlarged transparent view of an embodiment of the tension matrix in the unit according to the invention; - figure 2 represents one of its cross-sections; - figure 3 represents the enlarged lateral view of only the pin of the above-mentioned tension matrix, in which the teeth of the toothed member applied to one of its ends have not been drawn; - figure 4 represents the enlarged view from above SUBSTITUTE SHEET of a preferred embodiment of the above-mentioned toothed member; - figure 5 represents the longitudinal section of an embodiment of the tightening device at the moment at which it is joined to the tension matrix; - figure 6 represents a detailed view from which it is possible to deduce the position of the small connecting rod with two winches at that moment which contributes to effecting the blocking of the tension matrix onto the tightening device in figure 5; - figure 7 represents the longitudinal section of the tightening device itself which it has been made integral with the tension matrix, thereby constituting the unit according to the invention; - figure 8 represents a detailed view with the position of the above-mentioned connecting rod in the situation depicted in figure 7; - figure 9 represents another preferred embodiment of the unit according to the invention seen along a longitudinal section with the tightening device and the tension matrix having been made integral with one another; - figure 10 represents the enlarged view of the area of joining between the tension matrix and the tightening device in the embodiment of figure 9; - figure 11 represents a further embodiment of a particular type of tension matrix that can be used in the unit of the invention seen in exploded view along a longitudinal section; - figure 12 represents the tension matrix of figure SUBSTITUTE SHEET 11 in a view from below; - figure 13 represents the same tension matrix seen in a lateral view. When figures 1 and 2 are studied, it should be noted how casing 6 of tension matrix 1 in one embodiment includes, on the external wall that exhibits slot 6b for the introduction of the matrix, concave depression 6c shaped to essentially adapt itself to the wall of the tooth that is being operated on. This depression, together with the fact that casing 6, in the present embodiment, is constructed of a material having properties of elasticity, makes it possible to make tension matrix 1 adhere to teeth with various shapes in the best way possible. Since pin 7 is made with a rigid material, it is slightly "forced" into casing 6 which, with its elasticity, ensures in time the necessary adherence between the two parts. Again in figures 1 and 2, and also in figure 3, it can be seen how pin 7 of tension matrix 1 moves toothed wheel 7c and how it exhibits conical section 7a that converges toward the end that supports it. Such a characteristic implies that, by one angle of rotation of its pin 7, the matrix undergoes increasing traction from its side that is closes to said toothed wheel 7c toward the other side that is in proximity to the base of the cone. Since tension matrix 1 is applied with above- mentioned toothed wheel 7c turned toward the crown of the SUBSTITUTE SHEET tooth, the result that derives is that the matrix undergoes a greater traction corresponding to the cervical area of the tooth which normally has a circumferential development lower than that of the equatorial area, and the it adhere with greater precision over the whole surface of the tooth. As it can be seen from figure 1, casing 6 of the tension matrix is square and exhibits pairs of parallel flat surfaces that face one another. On at least one of these surfaces, but on two facing surfaces in the preferred embodiment represented, two grooves 3 are made so that two suitable shaped protruding members 4, 5 of the tightening device can grasp tension matrix 1 by engaging respectively within groove 3 of one of the surfaces and against the flat surface, which functions as a reference surface of opposing surface 6a. This task is accomplished by a pair of members 4, 5 figures 5-8 of tightening device 2 of which one member 4 is shaped as a hook and exhibits flat area 4a with which it can be supported on the above-mentioned reference surface of one surface 6a of casing 6 and the other member 5, in laminar form, is shaped to extremity 5a so as to be able to be engaged with above-mentioned groove 3 made on the opposing surface. These members 4, 5, once they have been engaged as said, function as pincers and make tension matrix 1 integral with tightening device 2 either while they are being applied in the oral cavity or while the matrix is being wound and tightened. It has been pointed out that in the drawings the matrices have not been represented, since visualizing their SUBSTITUTE SHEET position and shapes does not pose even the slightest problem for a person skilled in the art. Of the two protruding members 4, 5 first member 4 that is shaped as a hook is equipped on its end with extension 17 of handle 16 of tightening device 2 and second member 5 is equipped on its extremity with laminar body 5 which is attached under above-mentioned extension 17 in such a way that it can move over a preset sliding course parallel to the extension. Above-mentioned member 5 also has an oblong hole intended for the passing of winch 14, the function of which will be explained in the continuation of the present description. Second protruding member 5, in the embodiment described, exhibits two oblong notches 30, 31 through which two fastening screws 32, 33 pass which are attached to above- mentioned extension 17 of handle 16 and are equipped with broadened heads to which spacers 36, 37 and washers 34, 35 are also applied which have a diameter greater than the width of oblong notches 30, 31 so as to be able to support second member 5 itself while it, thanks to said oblong notches, moves over a sliding course with respect to extension 17 of handle 16. The above-mentioned sliding motion is transmitted to said second protruding member 5 by causing winch 14 mentioned earlier and that is equipped with two connecting rods 11, 13 attached to its ends to rotate. One of these connecting rods 13 passes with slub 13a hole 18 placed on second protruding member 5, a hole in SUBSTITUTE SHEET relation to which it is eccentric so that its rotation integral with connecting rod 14 causes the sliding that was described earlier (figures 6, 8). The other connecting rod 11 attached to the other end of winch 14 engages for a good part of its length into a toroidal groove 23 made on ratchet 12 that can be slid along coaxial shaft 10 parallel to the axis of extension 17 of handle 16, and thus parallel to the axis of device 2. The sliding of ratchet 12 causes the rotation of winch 14 and, by means of connecting rod 13, the consequent movement of member 5. The resulting sliding motion of the latter ends up parallel and consequently reduced to a preset extent, in relation to the shift of ratchet 12. This ratchet exhibits on the inside along its axis a sliding hold equipped with protrusion 22 which is connected in a sliding manner with groove 21 made on one section of shaft 10 through which it passes coaxially, parallel as mentioned before to extension 17 of handle 16 and supported at its ends, free to be able to rotate, by two supports 19, 20, with one 19 located at the extremity of extension 17 itself and the other 20 located on one part of handle 16. Between handle 16 and ratchet 12 there is then inserted, coaxially to shaft 10, compression spring 24 housed in housing 25 located in ratchet 12 itself. It is clear at this point that, with the same hand that holds handle 16, an operator can slide ratchet 12 along its axis coaxially to shaft 10, causing, as explained earlier, second protruding member 5 to slide and, at the same SUBSTITUTE SHEET time causing it rotate around its own axis, also bringing into rotation coaxial shaft 10 attached to it. Spring 24 mentioned above then ensures the return of ratchet 12 to its original position. At the extremity of above-mentioned shaft 10, besides support 19, conical toothed pinion 9 is fitted. Corresponding to it, at the end of extension 17 of handle 16, there is also attached, free to rotate, member 8 comprising conical toothed wheel 8a and toothed crown 8b integral and coaxial with one another. Conical toothed wheel 8a meshes with pinion 9 of shaft 10, and toothed crown 8b is sized to mesh with toothed wheel 7c of pin 7 of tension matrix 1 mentioned previously. With the unit according to the invention it is thus possible, by maneuvering ratchet 12 merely with the hand that is holding tightening device 2, to carry out the following operations: - to shift second protruding member 5 so as to allow for the insertion of tension matrix 1, by making it "mesh" with shaft 10; to allow the return of second protruding member 5 itself by means of spring 24 so as to make it go into groove 3 of casing 6 of tension matrix 1 by pushing tension matrix itself against flat part 4a of first fixed protruding member 4 so as to make tension matrix 1 and tightening device 2 integral with one another; - to apply tension matrix 1 (which will have obviously been previously equipped with the relative matrix) to the tooth to be reconstructed; - to make pin 7 of tension matrix 1 rotate by SUBSTITUTE SHEET tightening the matrix; - to again displace second protruding member 5 so as to disengage end 5a of protruding member 5 of tightening device (from tension matrix 1) , thus removing the device from the oral cavity of the patient. The practical and convenient features of these operations are evident which, as already said, reduce patient discomfort to the minimum. As in the preferred embodiment described to this point, it is furthermore noted that, since toothed member 7c of pin 7 of tension matrix is a toothed wheel, it may have, without any prejudice to the reliability of the attachment, dimensions that are much reduced in relation to those necessary given the present state of the art, something which involves a limited encumbrance of tension matrix 1 and makes possible the simultaneous application of various tension matrices to several adjoining teeth. The inventors of the present invention have also worked out a further embodiment thereof which allows for even greater maneuverability of the unit according to the invention, particularly with respect to the operation of disengaging the tension matrix and the matrix attached to it either from the tightening device or from the tooth on which the reconstruction work is being done. The realization of the unit described up to this point, as said, in fact includes a tightening device capable of causing the pin of the tension matrix to rotate to wind the matrix and to tighten it, as well as to unwind it, by causing it to rotate in the opposite direction, so as to SUBSTITUTE SHEET disengage it from the tooth after the operation. However it has been observed that this rotation to be effected in both directions, especially in some cases, involves a certain degree of difficulty, especially in the final operation of disengagement, because of the inelastic deformation of the generally metallic material of the matrix due to its being wound around the above-mentioned pin. With the embodiment that will now be described, this drawback has been eliminated by devising a unit of a different design that is adapted to effect a smooth immediate disengagement of the tightening device from the tension matrix without the pin of the tension matrix having to rotate for a second time, as already mentioned, for the purpose of freeing the matrix and disengaging it from the tooth to which it was applied. Observing figures 9 and 10, it is seen how the connection that makes tightening device 38 and tension matrix 101 integral with one another is effected by means of flexible fork 39 which ends at each of its ends in protruding part 39a, 39b and which, when it is inflected, connects in a reversible manner with shaped groove 40 located on part 41 attached to casing 41 of tension matrix 101. In the present embodiment represented in the drawings, the inflection of fork 39 is obtained by exerting traction on it, by means of small flexible hollow cable 42, which causes it to be inserted within cavity 43 of part 47 of tightening device 38, capable under such conditions of holding it with its two sides 39c, 39 d adhering against its internal walls. SUBSTITUTE SHEET This small flexible hollow cable 42 is attached at one end to middle part 39m of fork 39 and at the other end to activating member 53 attached to tightening device 38, which will be better explained below. The part attached to casing 41 of tension matrix 101 with which fork 39 is connected is, in the present embodiment, ring 41a that contains within it, by means of slightly forced connection, two protrusions 41d, 41e symmetrical to one another and belonging respectively to two likewise substantially symmetrical parts 41f, 41g of casing 41 of tension matrix 101 that face one another. These two parts 4If, 41g (fig. 13) are joined to each other along a vertical line H-H by means of the very material of which they are made; this material is chosen from among those that exhibit a sufficient degree of flexibility and elasticity and they are free to rotate in relation to one another, facing each other respectively to make up casing 41 and contain within them pin 44 or by moving away from one another freeing pin 44 and the matrix that is eventually attached to it. This rotation, as can be understood, takes place precisely around line H-H which passes through their area of junction. Therefore fork 39, as has been said, can be attached integrally to shaped groove 40 of above-mentioned ring 41a, making tension matrix 101 integral with tightening device 38. To ensure the rotation of pin 44 in an integral manner with flexible hollow cable 42, to cable 42 is attached SUBSTITUTE SHEET body 48 having a shaped section so as to engage integrally in the rotation with a cavity 44a located on the "head" of pin 44. Once the operation is finished, by exerting a truth on pin 44 by means of flexible wire 45 placed coaxially within small flexible hollow cable 42 and which rests on pin 44 itself with one end 45b, while having other end 45a attached to activation member 46, it is possible to cause pin 44 to slide axially, unthreading it from ring 41a together with two above-mentioned parts 4If, 41g of tension matrix 101 which are no longer held, which, for example, by the effect of a somewhat limited elasticity of the flexible material of which they are made, become half open thus leaving free pin 44 and the matrix attached to it, making it possible to disengage it smoothly from the tooth that has been treated. Tightening device 38 capable of making possible the procedure that has just been described is composed of: - terminal long-shaped part 47 that is inclined in relation to the longitudinal axis of tightening device 38 itself and carrying cavity 43 capable of holding within itself above-mentioned fork 39; - small flexible hollow cable 42 placed coaxially within long-shaped part 47 and attached, as said before, to one of its ends with middle part 39m of above-mentioned fork 39 and at its other end with a first activation member 53 of tightening device 38; - flexible wire 45 placed coaxially within above- mentioned hollow cable 42 and having one end 45b that rests against pin 44 which is attached, free to rotate, to casing SUBSTITUTE SHEET 41 of tension matrix 101, when this matrix is integral with the tightening device, and its other end 45a integral with second activation member 46 of tightening device 38. Tightening device 38 includes handle 49 that is integral with above-mentioned long-shaped part 47, rotating ratchet 53 that is integral in its rotation and in its sliding with flexible hollow cable 45, and second activation member 46, free to be able slide in relation to handle 49, so as to draw into its sliding above-mentioned flexible wire 45 in relation to which it is integral. Return springs 51, 52 then restore to its initial position activation member 46 after it has accomplished the above-mentioned sliding. In figures 11, 12, 13 an example of tension matrix is represented that can be used in the unit; it is equipped with a plurality (four in the figures) of peduncles 41k that serve to distance casing 41 tension matrix from the tooth, making possible the passage of the matrix. The materials for the construction of the tension matrix can be chosen from among the various types of materials and synthetic resins present on the market, with preference for those that endure temperatures higher than 120°C so as to make it possible to sterilize the tension matrix itself easily. Other embodiments either of the tightening device or of the tension matrix, that can be realized by an expert in the field according to the various requirements for use, are possible without going beyond the scope of the protection conferred by the attached claims. The examples that have SUBSTITUTE SHEET been described and depicted are to be considered preferred embodiments of the unit according to the invention, neither binding nor limiting in particular with respect to the shape, the relative positioning and the sizing of the various component parts. SUBSTITUTE SHEET

Claims: Claims 1. Unit of tension matrix and tightening device for use in dentistry comprising a tension matrix including a pin equipped with a slot for the introduction of the ends of the matrix and a casing, also equipped with a slot, which holds it within itself, and a tightening device, that can be attached to the above-mentioned pin and capable of causing it to rotate, causing the winding of the matrix around it, characterized in that tension matrix (1) and tightening device (2) are equipped with means of attachment (3, 4, 5) capable of making them integral with one another in a reversible manner. 2. Unit according to claim 1 wherein said means of attachment capable of making the tension matrix and the tightening device integral with one another are: - one or more grooves (3) and corresponding flat surface (6a) , located respectively on two opposite faces of the outer surface of casing (6) of tension matrix (1) and - a pair of protruding members (4, 5) of tightening device (2) capable of engaging in a reversible manner with at least one of the above-mentioned grooves (3) and with above- mentioned corresponding flat surface (6a) of casing (6) of tension matrix (1) . 3. Unit according to claim 2, wherein: - casing (6) of tension matrix (1) has a square section, and above-mentioned grooves (3) are located in proximity to one of its ends; - pin (7) of tension matrix (1) emerges from casing (6) with one end carrying first toothed member (7c) ; SUBSTITUTE SHEET - tightening device (2) is equipped with second toothed member (8) capable of connecting with above-mentioned first toothed member (7c) of tension matrix (1) and this second toothed member (8) is made to rotate by means of the motion of one or more parts (9, 10) of tightening device (2) and - tightening device (2) includes means that attach it to the above-mentioned pair of protruding members (4, 5) and of means capable of causing with their motion the shifting of at least one (5) of them so as to engage them or disengage them from above-mentioned grooves (3) and from corresponding surface (6a) of casing (6) of tension matrix (1). 4. Unit according to claim 3, comprised of: - handle (16) equipped with extension (17) that is integral with it and having circular hole (18) located in proximity to the handle itself and protruding member (4) shaped as a hook comprising flat part (4a) ; - member 8 formed by toothed crown (8b) and conical toothed wheel (8a) that are integral with one another and coaxial, attached to the end of above-mentioned extension (17) so that they can rotate; shaft (10) , parallel to above-mentioned extension, supported at its ends, free to be able to rotate, of two supports (19, 20) located respectively at the extremity of above-mentioned extension (17) and one part of above-mentioned handle (16) , shaft (10) carrying at one end conical toothed pinion (9) capable of meshing with above- mentioned conical toothed wheel (8a), and in proximity to the SUBSTITUTE SHEET other end grooved part (21) with at least one longitudinal groove parallel to the axis of shaft (10) itself; - ratchet (12) placed in proximity to the end of the shaft supported by handle (16) and which can be slid coaxially in relation to shaft (10) itself through a hole having within it protrusion (22) capable of meshing in a sliding manner with above-mentioned grooved part (21) of shaft (10) ; ratchet (12) on the outer surface of which is located toroidal neck (23) ; - compression spring (24) placed between ratchet (12) itself and handle (16) ; - first protruding member (4) shaped as a hook attached to the extremity of above-mentioned extension (17) , shaped so as to be supported with one flat surface (4a) against corresponding surface (6a) of casing (6) of tension matrix (1) ; - second protruding member (5) having one end (5a) shaped so as to be able to engage in above-mentioned groove (3) of tension matrix (1) , with the member itself (5) being attached on extension (17) of handle (16) so as to be able to effect a preset set course of sliding parallel to it, and it carries oblong hole (5b) corresponding to the end proximate to handle (16) ; - winch (14) having two connecting rods (11, 13) of which the first (11) engages, penetrating it, in above- mentioned toroidal neck (23) of ratchet (12) , and the second engages in above-mentioned oblong hole (5b) of second protruding member (5) after it has passed through circular hole (18) located on extension (17) of handle (16) , while the SUBSTITUTE SHEET diameter of second connecting rod (13) is less than that of the circular hole (18) itself and it is thus eccentric in relation to this hole (18) , which is occupied by a broadening (13a) of second connecting rod (13) ; - tension matrix (1) in which pin (7) has at one end toothed wheel (7c) capable of meshing with above- mentioned toothed crown (8b) of tightening device (2) . 5. Unit according to one of claims 3 or 4, wherein at least on the outer wall of the face of above-mentioned casing (6) that exhibits notch (6b) for the introduction of the matrix, there is located concave depression (6c) capable of adapting itself substantially to the shape of the tooth to which the tension matrix is applied. 6. Unit according to one of claims 3 to 5, wherein pin (7) of the tension matrix exhibits at least one conical section (7a) , whose conicity is convergent in the direction of above-mentioned first toothed member (7c) that has been applied onto it. 7. Unit according to any one of the previous claims, wherein casing (6) is made with a material having properties of elasticity, while pin (7) is made with a material that essentially cannot be elastically deformed. 8. Unit (102 fig. 9) according to claim 1, wherein the means of attachment capable of making the tension matrix and the tightening device integral with one another are: - shaped groove (40) located on the outer surface of one part (41a) attached to casing (41) of tension matrix (101) and - flexible fork (39) ending at each of its two ends SUBSTITUTE SHEET with protruding part (39a, 39b) capable of being connected integrally in a reversible manner with above-mentioned shaped groove (40) when fork (39) is inflected to a pre-determined extent. 9. Unit according to claim 8, wherein the part attached to casing (41) of tension matrix (101) is ring (41a) applied coaxially onto one portion of casing (41) of the tension matrix, while casing (41) is composed of two substantially symmetrical parts (41f, 41g) facing one another and both ending with protrusion (41d, 41e) , both protrusions (4Id, 41e) of both parts together make up the above-mentioned portion of casing (41) which is coaxially held by forced connection with ring (41a) . 10. Unit according to claim 9, wherein fork (39) is inflected so as to be connected in an integral manner with ring (41a) and it is inserted within cavity (43) shaped and sized so as to hold within itself fork (39) itself with its two sides (39c, 39d) adhering to its inner surface, while the insertion with this cavity (43) is effected by exerting traction on fork (39) itself by means of member (42) attached to tightening device (38) . 11. Unit according to claim 10, wherein the member of the tightening device that exerts the above-mentioned traction on fork (39) is small flexible hollow cable (42) attached at one end to fork (39) itself, and at the other end to first activation member (53) attached to tightening device (38) . 12. Unit according to claim 11 also including flexible wire (45) attached coaxially within said flexible SUBSTITUTE SHEET hollow cable (42) , and having one end (45a) attached to second activation member (46) and the other end (45b) protruding to a pre-determined extent within above-mentioned fork corresponding to the middle part (39m) in which it is inflected so as to rest on pin (44) of tension matrix (101) when tension matrix (101) and tightening device (38) are attached to one another integrally. 13. Unit according to claim 12, wherein two above- mentioned symmetrical parts (4If, 41g) of casing (41) of tension matrix (101) are joined to one another along vertical line (H-H) (fig. 13) so that each may rotate in relation to the other. 14. Unit according to claim 13, wherein two above- mentioned parts (4If, 41g) of casing (41) constitute a single piece, with the two parts themselves being made of flexible material and joined to one another along above-mentioned line (H-H) around which they can rotate thanks to the above- mentioned flexibility of the material of which they are made. 15. Unit according to either one of claims 8 or 14, wherein tightening device (38) is comprised of: - one terminal long-shaped part (47) inclined in relation to the longitudinal axis of the device (38) itself and having cavity (43) capable of holding within itself fork (39) ; - flexible hollow cable (42) placed coaxially within above-mentioned long-shaped part (47) and integral at one of its ends with middle part (39m) of fork (39) and at the other end with first activation member (53) of tightening device (38) ; SUBSTITUTE SHEET - flexible wire (45) placed coaxially within above- mentioned hollow cable (42) and having one end (45b) which rests against pin (44) which is attached, free to rotate, to casing (41) of tension matrix (101) , when this matrix is integral with the tightening device and the other end (45a) is integral with second activation member (46) of tightening device (38) ; tightening device (38) includes handle (49) that is integral with above-mentioned long-shaped part (47) , first activation member comprised of rotating ratchet (53) that is integral in its rotation and in its sliding with flexible hollow wire (42) and second activation member, free to be able to slide in relation to handle (49) , so as to draw into its sliding above-mentioned flexible wire (45) in relation to which it is integral. 18. Unit according to any of the previous claims, wherein both casing (6) and pin (7) are made of synthetic materials that can be subjected to sterilization procedures at temperatures higher than 120°C. SUBSTITUTE SHEET

Inventors: VON WEISSENFLUH BEAT, VON WEISSENFLUH HANS, VON WEISSENFLUH, BEAT, VON WEISSENFLUH, HANS
Applicants: VON WEISSENFLUH BEAT, WEISSENFLUH HANS VON, WEISSENFLUH HAWE NEOS, HAWE-NEOS DENTAL DR. H. VON WEISSENFLUH S.A., VON WEISSENFLUH, BEAT, VON WEISSENFLUH, HANS
Application year: 1993
Main classification: A61C5
IPC codes: A61C5