Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
  • A61C3/00—Dental tools or instruments
  • A61C3/16—Dentists' forceps or clamps for removing crowns
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
  • A61C3/00—Dental tools or instruments
  • A61C3/16—Dentists' forceps or clamps for removing crowns
  • A61C3/164—Dentists' forceps or clamps for removing crowns acting by percussion

Definitions

• the invention relates to a device with the features of the preamble of claim 1.
• the device is thus used to remove crowns, overlays, bridges, etc., which are fastened with fastening cement on one or more tooth stumps.
• a device of this type is known from US Pat. No. 3,889,376.
• a pull-off frame two holding jaws arranged opposite one another are provided, which are designed and intended for engagement on the lateral surface of the crown, bridge or the like and with the aid of which the crown can be removed from the tooth stump in a gentle manner.
• the device also has a device for applying a pulling force acting counter to the direction of insertion on the pulling frame, which consists of a bridge spanning the holding jaws and a screw which can be rotated in a nut thread of the bridge.
• To pull off the crown it is necessary to first drill through it so that the screw can be supported on the tooth stump when the pulling force is applied.
• the crown is injured and is not available for reuse.
• the holding jaws are at least partially made of a quickly hardenable plastic that adapts to the surface shape of the crown.
• a device in which two holding jaws are provided in a pull-off frame which are suspended around parallel pivot axes and which can be pivoted towards or away from each other.
• the use of this device presupposes that the holding jaws can be gripped under a protruding edge of the crown or can be attached there.
• the mobility of the holding jaws can be eliminated or determined by a nut, so that the holding jaws can no longer be detached from the crown to be removed.
• the chewing surface of the bridge must also be drilled a hole through which a spindle can be supported on the tooth stump.
• the spindle is mounted in the trigger frame with the help of a thread.
• a kind of ratchet wrench is used to apply the required pulling force. This is done by turning the spindle relative to the trigger frame.
• the development of force via the thread is also very slow, which is disadvantageous, because when the crowns are detached, it is only important to break open the fastening cement or to exceed the holding force of this fastening cement.
• Ratchet wrench, attached to the spindle requires a considerable height.
• the path required for the rotation of the ratchet wrench must be available.
• the holding jaws are provided in different designs and are thus intended to allow adaptation to different crowns, bridges or the like.
• This known device presupposes that the crown has a protruding edge, that is to say it is designed differently than is required in modern dentistry.
• the gums In the case of the tooth stumps which have been prepared up to below the gumline, the gums have to be displaced, especially for the attachment of the holding jaws. This affects especially the dental sheath with its fibers, which can ultimately lead to the loss of the tooth stump in the long term.
• the known device has the advantage that the acting force can be applied in the opposite direction to the insertion direction of the crown, the bridge or the like, provided that the holding jaws permit an attachment in a position or angular position corresponding to the insertion direction.
• Another known device according to US-PS 36 90 007 consists essentially of two pivotally hinged holding jaws, so that it is possible to attach these holding jaws opposite to the bridge or between two tooth stumps which are bridged by the bridge. In the approach position, the
• the shepherd's staff is an approximately 25 cm long staff with a small spade-shaped angled tip at one end. With this tip one tries to grasp under crown margins, distance buttons, pontics and other retention areas, which requires a corresponding formation of the crowns, bridges or the like.
• the other end of the shepherd's staff is shaped in such a way that a lead hammer can be struck in the pull-off direction.
• the practitioner must secure the work side with one hand; with the other hand it forms a guide and an abutment.
• the assistant without whom this work can usually not be carried out, then releases the necessary punch with the help of the hammer.
• a strong damping of the blow occurs through the hands of the practitioner and the construction-related elasticity of the shepherd's staff.
• the steeply rising pulse flank of the impact which would be important for tearing the fastener cement, is disadvantageously damped.
• the lead hammer is a relative has a large mass, which is in an unfavorable ratio to the relatively small mass of the dentures, the impact causes a force that acts on the denture part for too long. Since the shepherd's staff can only attack on one side, it is impossible for the force to act against the direction of insertion.
• Crown removal pliers are also known, e.g. B. from US-PS 3 834 026, the tongs are slightly modified compared to the extraction.
• the use of such pliers has the disadvantage that the pliers have a correspondingly long lever arm and the force that is released has a long-lasting effect. Often we not only exert an axial force, but also a twisting moment on the dentures. With extreme use in this sense, there is a risk that the tooth stump is often pulled out unintentionally.
• the invention has for its object to show a device of the type described above, with which it is possible to remove crowns, bridges and other dentures while destroying the cement cement of tooth stumps, namely by a short-term impact force acting against the insertion direction of the dentures.
• a short-term impact force acting against the insertion direction of the dentures Neither the tooth stump nor the dental prosthetic item to be removed should be damaged, so that they are available for reuse.
• the device for applying the pulling force has a movably mounted mass projectile which is guided in a movement path which ends at least counter to the insertion direction and can be acted upon by a releasable force source, that an anvil is provided at the end of the movement path the trigger frame and the jaws is connected.
• the mass projectile which can also be referred to as a firing pin, has a relatively low mass, which is in a favorable ratio to the mass of the dental prosthetic item to be removed.
• the mass projectile only requires a relatively small movement path in which it is guided. The path of movement must end at least opposite to the direction of insertion, but can of course also be provided parallel to the direction of insertion over its entire length.
• an anvil At the end of the trajectory, an anvil is required, which the mass projectile hits, whereby it suddenly transfers its kinetic energy to the anvil and thus to the trigger frame and the holding jaws.
• a damping in the transmission of this impulse is deliberately not provided, because it is important to destroy the holding force of the film of the cement without tilting or twisting the tooth stump. Since the dental prosthetic item is practically not deformed or damaged during the withdrawal movement, it is thus advantageously available for reuse.
• the use of the mass projectile ensures that the pulling force does not act on the tooth replacement part longer than necessary. The action takes place in the right direction so that a bridge or the like does not bend. The risk of injury to the patient's oral cavity is also excluded.
• the device according to the invention also offers the possibility of removing a denture which has a ceramic or a plastic veneer.
• the device can advantageously be designed to be so small that it can be used to remove crowns, etc. on distal ends; can be.
• the power source can be designed to be adjustable with regard to the acceleration of the mass storey, so that there is the possibility of utilizing the skill of the dentist and adjusting the power source only as much as is actually necessary for a reliable removal of the denture. This considerably protects the tooth stump.
• the mass projectile can have a bolt with an integrally formed head, which is guided in a straight line against the direction of insertion in a housing and is supported on the power source designed as a mechanical spring.
• a trigger is provided to release the power source on the bolt.
• the anvil consists of an edge of the housing which surrounds the bolt and on which the head of the bolt impacts at the end of its path of movement.
• One or more disc springs in particular in the usual package arrangement, which are capable of exerting a considerable force with a small spring travel can preferably be used as the source of force.
• the mass projectile is thus considerably accelerated when triggered, so that the guideway can be kept relatively short, which is essential for use in the distally terminal area.
• This Training of course also allows individual adjustment of the preload of the package of disc springs in a way that is considered useful and sufficient for the respective application.
• the housing can also carry a marking so that the compression of the disc springs to different extents and thus the preload for the delivery of the respective pulse can be adjusted in a reproducible manner.
• the bolt can have a threaded shaft and an associated nut for adjusting the pretension of the power source, the nut being supported on the plate springs and, on the other hand, the plate springs in turn being supported on the housing of the device.
• the bolt can have a circumferential groove in which the trigger designed as a slide engages. Due to the compression of the force source designed as a spring, the groove reaches the area of the trigger so that it can be inserted into the groove and thus prevents the movement of the bolt from occurring.
• the trigger can be moved by train or pressure in the manner of a Bowden cable or similar to a camera trigger in such a way that it emerges from the groove and releases it, so that the mass projectile is accelerated accordingly by the power source and at the end of the acceleration path the respective force is transmitted in pulses.
• the trigger can of course also engage the head of the bolt.
• the trigger frame carrying the holding jaws and the housing of the device for applying the trigger force can be connectable to one another as separate parts.
• the holding jaws differently, but also the possibility of designing the device for applying the pulling force differently, for example in such a way that a first device with plate springs in a first specific prestressing area and a second device with plate springs in a second one after that Bias area are provided.
• the various combinations of the components of the device are thus easily possible, as this appears to be useful and necessary for the respective application.
• the holding jaws on the outer surface of the crown, bridge o .. dgX. attack can also be designed or arranged in such a way that, in the case of two opposite sides, they only act on the area assigned to a tooth on the tooth replacement. If the pull-off frame is made wider, for example four or six holding jaws, each arranged in pairs opposite one another, or continuous holding jaws can be provided, which is particularly advantageous for pulling off a bridge extending over several tooth stumps. Then it is also possible to arrange only one or more devices for applying the pulling force distributed over the length of the trigger frame and to trigger these devices together so that the bridge is lifted simultaneously over its entire length.
• the design described has the further advantage that the adjustability of the power source can be dispensed with and instead provide a stepped series of devices for applying a constant pulling force, which is then used selectively.
• the mass projectile is designed as a ball which is guided in a pipe-like movement path and is driven by compressed air as a power source.
• the anvil has a web arranged at the end of the movement path.
• the ball is accelerated in the area of the movement path by introducing compressed air into the movement path.
• At the end of the trajectory it hits a web on the trigger frame, which is designed so that the air displaced by the ball can escape.
• the bridge transmits the impact impulse to the trigger frame and this in turn to the holding jaws.
• the path of movement is designed to be comparatively longer and preferably curved in a pipe-like manner so that the end is opposite to the direction of insertion.
• the trigger is implemented here in the form of a valve, which serves to introduce the compressed air into the path of movement, which is designed as a curved tube. A different dosage and thus an adjustability of the acting compressed air or force is also possible.
• Fig. 3 is a sectional view of the essential parts of a third embodiment
• a device 1 for applying a pull-off force is placed with its housing 2 on a pull-off frame 3 or is formed in one piece.
• the trigger frame 3 carries two holding jaws 4, which are housed in non-contiguous wall parts.
• the trigger frame 3 is open at the front and rear, that is in the direction of extension of the jaw or teeth.
• a tooth stump 5 is shown, on which a crown 6 with a facing 7 is placed and fastened with the aid of a film 8 of fastening cement.
• the holding jaws 4 do not engage in the area of the edge 9 of the crown 6 or the facing 7, but in the area of the lateral surface 10; the holding jaws 4 can each consist of a mass piece made of thermoplastic, which is stored and held in openings 11 of the trigger frame 3.
• the device 1 In the area of the housing 2, the device 1 has an inwardly projecting edge 12 and a type of intermediate floor 13, in the area of which a plurality of springs 15, which are designed as plate springs, are supported by means of a collar 14.
• a mass projectile 17 in the form of a bolt 18 with a head 19 is mounted such that it can be displaced to a limited extent.
• the bolt 18 has a threaded shaft 20, on which a nut 21 with a corresponding counter thread can be screwed on to different degrees.
• The. Nut 21 has a bead 22 which extends beyond the housing 2.
• the housing can carry 2 markings 23, so that depending on how far the nut 21 is screwed onto the threaded shaft 20 and thus the spring 15 is pretensioned, a corresponding display of the pretensioning force is possible with the aid of the markings 23.
• the springs 15 are supported on the intermediate floor 13 and, on the other hand, come into contact with the nut 21, so that the mass projectile 17 is acted upon by this power source in the opposite direction to the insertion direction 16.
• the bolt 18 has a circumferential groove 24, in which a trigger 25 engages with the aid of a slide 26, so that the parts assume the position shown in FIG.
• the distance 27 corresponds to the possible stroke of the mass projectile 17 when released by the trigger 25 or the slide 26, so that a movement path is thus created opposite the insertion direction 16, at the end of which the head 19 onto the projecting edge 12 in the manner of an anvil 28 hits and thus suddenly transmits its kinetic energy to the intermediate floor 13 and thus to the housing 2, the trigger frame 3 and the holding plates 4.
• the trigger 25 can be designed in the manner of a Bowden cable - can be triggered by train or by pressure.
• the device is handled as follows. To pull off the crown 6, it is first necessary to preheat the holding jaws 4, for example by immersing them in a water bath, so that a plastic state of the thermoplastic mas piece is reached. Preheated in this way, the device is then pushed onto the crown 6 in accordance with the insertion direction 16, the holding jaws 4 coming into contact with each other on the lateral surface 10 and the thermoplastic material. solidified by replicating the corresponding shape.
• the trigger 25 is actuated, that is to say the slide 26 is pulled out of the groove 24, so that the force of the springs 15 acts on the mass projectile 17 opposite the insertion direction 16 centrally above the crown 6.
• the ground floor 17 flies upwards until the head 19 suddenly strikes the anvil 28 at the end of the movement path.
• the movement path of the ground floor 17 is thus ended and the kinetic energy of the ground floor 17 is ultimately transmitted to the crown 6 as an abrupt impulse, so that the holding force of the film 8 of the fastening cement is exceeded with a very short exposure time. So the crown 6 of that. Tooth stump 5 loosened.
• the force was applied only for a very short time, using a relatively small mass of the mass projectile 17 and acting opposite to the direction of insertion 16, the two holding jaws 4 acting on the crown 6 opposite one another. A straight-line pulling movement opposite to the insertion direction 16 is thus achieved.
• the springs 15 can be exchanged for other springs, that is to say those with a different preload force, if the transmittable impact pulse is to be adapted to changing conditions. This is the case when the area of the one spring 15 that is covered by the markings 23 is not sufficient. It also goes without saying that there is also the possibility of ultimately connecting the nut 21 to the threaded shaft 20 so that it cannot be rotated, so that such a device cannot be adjusted with regard to the force source that can be applied, but always reproducibly has and delivers the same pretensioning force. Devices can then be manufactured and used with different strength sources, which can be selected depending on the application.
• Fig. 2 shows a device which is in principle very similar, but is divided horizontally, ie the housing 2 and the trigger frame 3 do not form an integral material part here, but can be connected to one another by means of a thread 29.
• the pull-off frame 3 is designed to be correspondingly wide or long, with different pairs of holding jaws 4 being provided one behind the other.
• That shark Tebacken 4 can consist of thermoplastic mass pieces (FIG. 1) or also of ratchet screws 30 or also of shaped pieces 31 (FIG. 2).
• a plug-in connection also offers itself here to the person skilled in the art, for example also in such a way that the trigger frame 3 extends, for example, over the distance of three tooth stumps conceivable side by side, while on the top of such a trigger frame 3 z.
• the holding jaws 4 can also be varied accordingly, it being possible to provide the openings 11 with a corresponding thread in order to screw in the knurled screws 30 accordingly. It goes without saying that corresponding depressions must be provided on the crown 6 in connection with it in order to transmit the required pull-off force. However, these depressions are not provided in the area of the edge 9, but also in the area of the lateral surface 10.
• a shaped piece 31 can also be fixed in the openings 11 with: with the aid of lock nuts 32 and placed and arranged differently within the opening 16.
• the function of the device according to FIG. 2 corresponds to that according to FIG. 1.
• the trigger frame 3 can be seen here in a side view, the top view of the ratchet screw 30 revealing the position of the holding jaws 4 thus realized.
• the housing 2 of the device 1 consists essentially of a pipe-like formed tube, in which a ball 33 moves as a mass projectile 17 to a limited extent. This path of movement corresponding to the curvature of the tube or the housing ends in any case opposite to the direction of insertion 16, the anvil 28 being formed by a web 34 in which one or more openings for the exit of the ball 33 in the housing 2 are displaced Air. Via a hose connection 35, compressed air can be directed onto the ball via a valve, not shown
• the device can have a second compressed air line 36 in the area of the housing 2, which opens into the path of movement of the ball 33 in the area of the web 34 and thus - understandably with considerably reduced pressure - acts on the return of the ball 33 to its initial position.
• the two compressed air lines can thus be controlled alternately, or in another way.

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• Health & Medical Sciences (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Dentistry (AREA)
• Epidemiology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Dental Tools And Instruments Or Auxiliary Dental Instruments (AREA)

Priority Applications (6)

Applications Claiming Priority (1)

Publications (1)

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ID=8165073

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Cited By (1)

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Citations (6)

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• 1985
  • 1985-10-30 US US06/913,675 patent/US4725233A/en not_active Expired - Fee Related
  • 1985-10-30 EP EP85905797A patent/EP0232276B1/de not_active Expired
  • 1985-10-30 WO PCT/EP1985/000577 patent/WO1987002573A1/de not_active Ceased
  • 1985-10-30 JP JP60505227A patent/JPS63501194A/ja active Granted

Patent Citations (6)

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