A crown breaking tool

Abstract

This invention provides a crown fracture tool. The tool includes a gripping part, with a connecting component at its front end. The connecting component forms an angle with the gripping part. A first fixing plate and a second fixing plate are fixedly connected at a distance from the end of the connecting component. The first fixing plate has an L-shaped cross-section, and the second fixing plate has an arc-shaped cross-section. A fan-shaped cavity is formed between the first and second fixing plates to surround the dental flap. The crown fracture tool provided by this invention allows the fan-shaped cavity formed by the two fixing plates to conform to the shape of the dental flap, increasing the contact area and preventing breakage and detachment. The connecting component allows for flexible adjustment of the fixing plate angles to adapt to different tooth positions and flap orientations, reducing operational fatigue and tooth damage. The angled design between the gripping part and the connecting component avoids obstructing the field of vision and ensures appropriate force application, improving operational convenience and safety, shortening treatment time, and reducing patient discomfort.

Description

Technical Field

[0001] This utility model relates to the field of dental instruments, and in particular to a tool for breaking dental crowns. Background Technology

[0002] In the extraction of impacted mandibular third molars, the root is often close to the mandibular nerve canal, making a single extraction risky. The best approach is to separate the crown and extract only the crown, allowing the root to detach from the mandibular nerve canal before selective extraction. This significantly reduces the risk of nerve damage. In the removal of vertically impacted and slightly mesial impacted teeth, the crown cannot be divided along the cervical region in one go due to limitations in the cutting angle. The traditional method involves using a high-speed dental handpiece with a cutting bur to create a cross-shaped or radial cutting groove within the crown, dividing it into multiple independent segments. Then, using non-specialized instruments such as dental elevators, external force is applied to the segments, causing them to break off from the cervical region while preserving the root intact.

[0003] However, conventional instruments have significant limitations in actual operation. Taking dental elevators as an example, their tips are curved, resulting in poor contact with the surface of the dental flap. They can only apply force by contacting the edge of the flap with the tip, which not only easily leads to concentrated force points causing the flap to break, but also may cause the tooth fragment to fall into the deep part of the oral cavity due to unstable clamping, increasing the risk of choking and accidental swallowing for the patient. At the same time, it will also prolong the operation time and increase the patient's discomfort during the treatment process.

[0004] While existing technologies have attempted to optimize specialized tools for crown removal, such as crown segmentation breakers, which use curved clamping arms to wrap around the tooth flap, the angle and spacing of these arms are fixed and cannot be adjusted according to different tooth positions (e.g., anterior and posterior teeth), different flap sizes, and tilt directions. In clinical practice, posterior tooth crowns have complex morphologies and large occlusal surfaces, and the orientation of the segmented flaps varies. Fixed-angle clamping arms cannot accurately fit the flap surface, often requiring medical staff to adjust their hand posture to accommodate the flap position. This not only increases operational fatigue but may also lead to accidental damage to tooth tissue due to deviations in the direction of force, affecting subsequent restorative outcomes.

[0005] Furthermore, neither traditional tools nor some existing specialized tools have considered the stability of the dental flap after clamping. Because the surface of the dental flap often has caries defects or irregular edges after cutting, slippage is likely to occur during clamping. Medical staff need to repeatedly adjust the clamping position, which not only reduces treatment efficiency but may also cause wear and tear on the healthy tooth tissue around the flap due to repeated attempts, further damaging the integrity of the tooth structure and adversely affecting the patient's subsequent treatment.

[0006] Therefore, it is necessary to provide a crown fracture tool to solve the above-mentioned technical problems. Utility Model Content

[0007] This invention provides a dental crown fracture tool that solves the problem of inconvenience in using existing dental crown fracture instruments.

[0008] To solve the above-mentioned technical problems, the present invention provides a crown breaking tool, including a holding part, a connecting component at the front end of the holding part, an angle between the connecting component and the holding part, and a first fixing piece and a second fixing piece fixedly connected at intervals at the end of the connecting component. The first fixing piece has an L-shaped cross section, the second fixing piece has an arc-shaped cross section, and a fan-shaped cavity for surrounding the tooth flap is formed between the first fixing piece and the second fixing piece.

[0009] Preferably, the connecting assembly includes a rotating column rotatably disposed at the front end of the grip portion and a movable sleeve. The bottom end of the rotating column extends to the outside of the grip portion, and the movable sleeve is sleeved on the outside of the lower end of the rotating column. The movable sleeve can move along the axial direction of the rotating column and rotate synchronously with the rotating column.

[0010] Preferably, the bottom of the front end of the gripping part is provided with a plurality of positioning holes evenly spaced along the ring, the top of the movable sleeve is provided with a corresponding number of fixing blocks evenly spaced along the ring, and an elastic element is provided between the bottom end of the rotating column and the bottom end of the inner wall of the movable sleeve. The elastic element pulls the movable sleeve tight so that the fixing blocks are correspondingly inserted into the positioning holes to fix the movable sleeve.

[0011] Preferably, the inner wall of the movable sleeve is provided with a plurality of raised guide strips at intervals, and the lower part of the surface of the rotating column is provided with corresponding guide grooves at intervals, and the guide strips slide along the inside of the guide grooves.

[0012] Preferably, the outer ring surfaces of the upper part of the first fixing piece and the second fixing piece are both formed with the same arc as the outer ring surface of the lower end of the movable sleeve, and the first fixing piece and the second fixing piece are both made of elastic metal. The outer ring surface of the lower end of the movable sleeve and the upper part of the first fixing piece and the second fixing piece are provided with connected external threads. The lower part of the surface of the movable sleeve is connected to a nut through the external threads. When the nut is screwed to the outer surface of the upper part of the first fixing piece and the second fixing piece, the first fixing piece and the second fixing piece are tightened.

[0013] Preferably, the front end of the gripping part is provided with a mounting hole for mounting the rotating column.

[0014] Compared with related technologies, the crown fracture tool provided by this utility model has the following beneficial effects: This invention provides a dental crown fracture tool. An L-shaped first fixing piece and an arc-shaped second fixing piece form a fan-shaped cavity, which can precisely fit the straight and curved surfaces of the dental flap, significantly increasing the contact area and avoiding the flap breakage caused by concentrated force points in traditional instruments. The open design can accommodate dental flaps of different sizes, preventing flap dislodgement and reducing the risk of dental procedures. The rotating column and movable sleeve in the connecting component, combined with the limiting structure of the elastic element, positioning hole, and fixing block, allow for flexible adjustment of the fixing piece angle to accommodate dental flaps of different positions and orientations. This ensures the grip is always positioned in a convenient location facing the patient, reducing the difficulty of adjusting hand posture for medical staff, alleviating operational fatigue, and preventing tooth damage. Furthermore, the angle between the grip and the connecting component prevents the hand from obstructing the operating view and allows the force direction to better match the needs of flap fracture. Stable force can be applied without excessive wrist bending, improving operational convenience and safety, shortening treatment time, and reducing patient discomfort during treatment. Attached Figure Description

[0015] Figure 1 A schematic diagram of a preferred embodiment of the crown breaking tool provided by this utility model; Figure 2 This is an exploded view of the structure of this utility model; Figure 3 This is an exploded view of the structure of this utility model; Figure 4 for Figure 1 The diagram shows the structure of the gripping part; Figure 5 for Figure 2 The diagram shows the structure of the movable sleeve. Figure 6 This is a cross-sectional structural diagram of the rotating column and movable sleeve of this utility model.

[0016] The following are the labels in the diagram: 1. Grip, 11. Mounting hole, 12. Positioning hole, 2. First fixing piece, 3. Second fixing piece, 4. Rotating column, 41. Guide groove, 5. Movable sleeve, 51. Guide strip, 52. Fixing block, 6. Elastic element. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments. Example

[0018] Please refer to the following: Figure 1 The crown breaking tool includes a holding part 1, and a connecting component is provided at the front end of the holding part 1. An angle is formed between the connecting component and the holding part 1. A first fixing piece 2 and a second fixing piece 3 are fixedly connected at intervals at the end of the connecting component. The first fixing piece 2 has an L-shaped cross section, and the second fixing piece 3 has an arc-shaped cross section. A fan-shaped cavity for surrounding the dental flap is formed between the first fixing piece 2 and the second fixing piece 3.

[0019] During treatment, the crown needs to be cut first to form a cross-shaped cutting groove, dividing the crown into four segments. Each segment has an outer surface and two mutually perpendicular straight surfaces. Then, using a crown breaking tool, the first fixing piece 2 and the second fixing piece 3 are placed on one segment. Then, the holding part 1 is turned in the appropriate direction, and the first fixing piece 2 and the second fixing piece 3 are tilted through the connecting component, thereby breaking off and removing the segment.

[0020] In this embodiment, an angle is formed between the gripping part 1 and the connecting component. The angle can be 60-120°, preferably 90°. When the first fixing piece 2 and the second fixing piece 3 wrap around the dental flap, the gripping part 1 can extend out from the patient's face, making it easier for medical staff to manipulate.

[0021] The two sides of the first fixing piece 2 and the two ends of the second fixing piece 3 form a gap, and the two are not connected to each other, so as to increase the size of the fan-shaped cavity and can accommodate different tooth flaps.

[0022] The sizes of the dental flaps are not the same and cannot be completely matched with the size of the fan-shaped cavity. However, since the dental flap has height, the first fixing plate 2 and the second fixing plate 3 do not need to tightly wrap the dental flap. They only need to be inserted downwards as deeply as possible so that the dental flap is in the fan-shaped cavity. This allows the first fixing plate 2 and the second fixing plate 3 to apply pressure to the side of the dental flap when tilted, causing it to break. Therefore, the size of the fan-shaped cavity can be slightly larger than the size of the dental flap.

[0023] Please refer to Figure 2 and 4 -6. The connecting assembly includes a rotating column 4 rotatably disposed at the front end of the grip 1 and a movable sleeve 5. The bottom end of the rotating column 4 extends to the outside of the grip 1, and the movable sleeve 5 is sleeved on the outside of the lower end of the rotating column 4. The movable sleeve 5 can move along the axial direction of the rotating column 4 and rotate synchronously with the rotating column 4.

[0024] Since the four tooth flaps are oriented differently after the crown is cut, and their right-angle positions and arc positions are different, and medical staff can only operate from the front of the patient, if the direction and position of the first fixation piece 2 and the second fixation piece 3 relative to the holding part 1 are fixed, it is impossible to break the tooth flaps in different positions. Therefore, it is necessary to adjust the whole formed by the first fixation piece 2 and the second fixation piece 3 relative to the holding part 1 so that the direction of the fan-shaped cavity can be changed to adapt to the tooth flaps in different positions.

[0025] In this embodiment, the first fixing piece 2 and the second fixing piece 3 are disposed at the bottom of the movable sleeve 5. The movable sleeve 5 and the rotating column 4 can rotate synchronously. The rotating column 4 and the gripping part 1 are rotatably connected. Therefore, the movable sleeve 5 can be rotated by rotating the rotating column 4, thereby driving the first fixing piece 2 and the second fixing piece 3 to rotate as a whole, adjusting the position of the fan-shaped cavity formed by the two. The adjustment is made according to the different positions and directions of the dental flap, thereby ensuring that while the first fixing piece 2 and the second fixing piece 3 cover the dental flap, the gripping part 1 is generally located in the front direction of the patient, which is convenient for medical staff to operate. The direction of its end may be slightly deviated, but it does not affect the operation.

[0026] The bottom of the front end of the gripping part 1 is provided with a plurality of positioning holes 12 evenly spaced along the ring. The top of the movable sleeve 5 is provided with a corresponding number of fixing blocks 52 evenly spaced along the ring. An elastic element 6 is provided between the bottom end of the rotating column 4 and the bottom end of the inner wall of the movable sleeve 5. The elastic element 6 pulls the movable sleeve 5 tight so that the fixing blocks 52 are inserted into the positioning holes 12 to fix the movable sleeve 5.

[0027] If the movable sleeve 5 and the rotating column 4 are simply rotated to the grip part 1, relative rotation may occur when force is applied to break them, affecting the force exerted and potentially causing additional damage. Therefore, a limiting function is required.

[0028] The elastic element 6 can be a tension spring, which is always in a stretched state, so that its elastic force always tends to pull the movable sleeve 5 upward. Under normal conditions, the movable sleeve 5 is pulled by the elastic element 6, which makes the fixed block 52 engage with the positioning hole 12, so that the movable sleeve 5 and the grip part 1 are relatively fixed and will not rotate relative to each other. When it is necessary to adjust the direction and angle of the fan-shaped cavity, the movable sleeve 5 is pulled down to disengage the fixed block 52 from the positioning hole 12. At this time, the elastic element 6 is stretched more and the elastic force increases. Then the movable sleeve 5 is rotated to a suitable angle through the rotating column 4, and then the movable sleeve 5 is released, so that it is reset upward under the action of the elastic force, so that the fixed block 52 engages again in the corresponding positioning hole 12, and the fixation is achieved, thus completing the adjustment.

[0029] The inner wall of the movable sleeve 5 is provided with multiple protruding guide strips 51 at intervals, and the lower part of the surface of the rotating column 4 is provided with corresponding guide grooves 41 at intervals. The guide strips 51 slide along the inside of the guide grooves 41.

[0030] To prevent the movable sleeve 5 from rotating relative to the rotating shaft 4, which would cause the elastic element 6 to be subjected to torsional force and affect its normal use, guide strip 51 and guide groove 41 are provided to guide the movable sleeve 5, so that the movable sleeve 5 can move along the axis of the rotating column 4 and rotate synchronously with the rotating column 4, but cannot rotate relative to it.

[0031] Please refer to Figure 2 , 3In this embodiment, the outer ring surfaces of the upper part of the first fixing piece 2 and the second fixing piece 3 both form the same arc as the outer ring surface of the lower end of the movable sleeve 5, and the first fixing piece 2 and the second fixing piece 3 are both made of elastic metal. The outer ring surface of the lower end of the movable sleeve 5 and the upper part of the first fixing piece 2 and the second fixing piece 3 are provided with connected external threads. The lower part of the surface of the movable sleeve 5 is connected to the nut 7 through the external threads. When the nut 7 is screwed to the outer surface of the upper part of the first fixing piece 2 and the second fixing piece 3, it tightens the first fixing piece 2 and the second fixing piece 3.

[0032] In this embodiment, the upper outer ring surfaces of both the first fixing piece 2 and the second fixing piece 3 are curved surfaces with a relatively thick thickness, while the two sides of the lower part of the first fixing piece 2 are thinner, forming two thinner planes that can be inserted into the gap for cutting the tooth crown. The lower part of the second fixing piece 3 can also be processed into a thinner curved surface.

[0033] The first fixing piece 2 and the second fixing piece 3 are respectively made of elastic metal material, so that they can produce a small amount of deformation while having sufficient strength, making it easy to insert into the cutting slit of the crown. However, the two fixing pieces made of elastic material may also deform during the process of breaking them with force, which will affect normal operation. Therefore, a nut 7 is set. After the first fixing piece 2 is inserted into the cutting slit of the crown, the nut 7 is screwed onto the two fixing pieces to tighten them as much as possible, reducing the degree of deformation when breaking them with force, and preventing their deformation and force from canceling each other out.

[0034] The front end of the gripping part 1 is provided with a mounting hole 11 for mounting the rotating column 4. The rotating shaft 4 can be a structure with a disc-shaped upper part and a column-shaped lower part, and is rotatably mounted in the mounting hole 11 by means of bearings or the like.

[0035] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the content of this utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A tool for breaking dental crowns, characterized in that: The device includes a gripping part (1), and a connecting component is provided at the front end of the gripping part (1). The connecting component forms an angle with the gripping part (1). A first fixing piece (2) and a second fixing piece (3) are fixedly connected at intervals at the end of the connecting component. The first fixing piece (2) has an L-shaped cross section, and the second fixing piece (3) has an arc-shaped cross section. A fan-shaped cavity for surrounding the dental flap is formed between the first fixing piece (2) and the second fixing piece (3).

2. The crown breaking tool according to claim 1, characterized in that, The connecting assembly includes a rotating column (4) rotatably disposed at the front end of the grip (1) and a movable sleeve (5). The bottom end of the rotating column (4) extends to the outside of the grip (1), and the movable sleeve (5) is sleeved on the outside of the lower end of the rotating column (4). The movable sleeve (5) can move along the axial direction of the rotating column (4) and rotate synchronously with the rotating column (4).

3. The crown breaking tool according to claim 2, characterized in that, The bottom of the front end of the grip (1) is provided with a plurality of positioning holes (12) evenly spaced along the ring. The top of the movable sleeve (5) is provided with a corresponding number of fixing blocks (52) evenly spaced along the ring. An elastic element (6) is provided between the bottom end of the rotating column (4) and the bottom end of the inner wall of the movable sleeve (5). The elastic element (6) pulls the movable sleeve (5) tight so that the fixing blocks (52) are inserted into the positioning holes (12) to fix the movable sleeve (5).

4. The crown breaking tool according to claim 2, characterized in that, The inner wall of the movable sleeve (5) is provided with a plurality of protruding guide strips (51) at intervals, and the lower part of the surface of the rotating column (4) is provided with corresponding guide grooves (41) at intervals, and the guide strips (51) slide along the inside of the guide grooves (41).

5. The crown breaking tool according to claim 2, characterized in that, The upper outer ring surfaces of the first fixing plate (2) and the second fixing plate (3) are both formed with the same arc as the lower outer ring surface of the movable sleeve (5). The first fixing plate (2) and the second fixing plate (3) are both made of elastic metal. The lower outer ring surface of the movable sleeve (5) and the upper part of the first fixing plate (2) and the second fixing plate (3) are provided with connected external threads. The lower part of the surface of the movable sleeve (5) is connected to a nut (7) through the external thread. When the nut (7) is screwed to the upper outer surface of the first fixing plate (2) and the second fixing plate (3), the first fixing plate (2) and the second fixing plate (3) are tightened.

6. The crown breaking tool according to claim 2, characterized in that, The front end of the grip (1) is provided with a mounting hole (11) for mounting the rotating column (4).

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