JP2015217254A - Medical drill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medical drill, after forming a through-hole in a bone, inhibiting a cylindrical drill member 10 from damaging a tissue in the periphery of the bone.SOLUTION: A medical drill 100 for forming a through-hole in a bone, includes: a rotatable cylindrical drill member 10; a drive force transmission member 30 that transmits rotary driving force from a drive source to the cylindrical drill member 10 via a projection member 20 provided at an inner peripheral side of the cylindrical drill member 10, to rotate the cylindrical drill member 10; and a spring 34. When the cylindrical drill member 10 cuts the bone, the projection member 20, while compressing the spring 34 in a rotation axis direction, is engaged with the cylindrical drill member 10 to move to an engagement position for transmitting the rotary driving force, when the cylindrical drill member 10 penetrates through the bone, receives elastic force from the spring 34 in the insertion direction of the cylindrical drill member 10 to project from the through-hole and moves to a non-engagement position where no rotary driving force is transmitted to the cylindrical drill member 10.

Description

  The present invention relates to a medical drill.

  When performing medical treatment such as surgery or treatment, a medical drill is used when it is necessary to make a hole in the bone of the human body. For example, in implant treatment, it is necessary to form a hole in the maxillary or mandibular bone covered with gums (gingiva) in order to embed an artificial dental root of an implant (hereinafter referred to as an implant body). An implant drill as a medical drill is used to form a hole in the maxillary bone (for example, Patent Document 1).

JP 2011-152238 A

  Here, in the case of implant treatment, there is the following problem when a hole is made in the maxillary bone of a human body. There is a cavity called Sinus, next to the nose and below the eyes. When drilling a hole in the maxilla to embed the implant body, if the drill penetrates the bone and breaks the mucosa (Schneider's membrane, maxillary sinus mucosa) on the back side of the bone, the patient becomes infected, and empyema or maxilla There is a risk of getting sick called sinusitis. Note that the thickness of the Schneider film is about 0.5 mm. Such a problem is less likely to occur if the bone is thick and the distance from the bone surface to the maxillary sinus is long, but in many cases there is only a margin of several millimeters until the drill penetrates the bone.

  Also, depending on the patient, the maxillary bone thickness may be shorter than the length of the implant body. For example, some patients have a maxillary bone thickness of about 5 mm for an implant body length of 9 mm. Therefore, an operation called a sinus lift method (socket lift method) is performed to increase the bone thickness of the maxillary sinus. In the sinus lift method, first, a drill hole for an implant is used to open a through hole in the maxillary bone so as not to break the mucous membrane. Then, the implant body is inserted into the through hole, and the implant body is pressed a little against the mucous membrane so as not to break. In this state, after waiting for several months, new bone is formed between the mucous membrane and the bone, and the implant body is firmly covered with the bone, so that the implant body is stabilized.

  As described above, when the sinus lift method is employed, it is necessary to form a through hole in the maxillary bone using an implant drill without breaking the mucous membrane on the back side of the bone. When directly forming a through-hole using an implant drill, there is a high risk of rupturing the mucous membrane. Therefore, the following method has been mainly used as a method for forming a through-hole so as not to break the mucous membrane. First, a detailed actual measurement value of the maxillary bone thickness is measured with a CT image or the like, and then the maxillary bone is cut using an implant drill having a length that does not penetrate the bone. Then, using a chisel, the bone that has been cut and has lost its thickness is broken to form a through hole, the implant body is inserted through the through hole, and the mucous membrane is pushed up. As described above, skilled and advanced techniques are required to form a through hole without breaking the mucous membrane.

  Therefore, an object of the present invention is to provide a medical drill that forms a through-hole in a bone, and the medical drill suppresses a drill member from damaging tissue around the bone. In particular, an object of the present invention is to provide a medical drill that suppresses breaking of the mucous membrane on the back side of the bone.

  The present invention employs the following means in order to solve the above problems.

That is, the medical drill of the present invention is
A medical drill for forming a through hole in a bone,
A cylindrical rotatable drill member;
A projecting member provided on the inner peripheral side of the drill member;
A driving force transmitting member for transmitting a rotational driving force from a driving source to the drill member via the protruding member, and rotating the drill member;
An elastic spring,
Have
The protruding member is
When the drill member cuts the bone, it engages with the drill member while transmitting the rotational driving force while compressing the elastic spring in a direction opposite to the insertion direction of the drill member while hitting the surface of the bone. Go to
When the drill member penetrates the bone, the drill member receives an elastic force from the elastic spring in the insertion direction, protrudes from the through hole, and moves to a non-engagement position that does not transmit a rotational driving force to the drill member. To do.

  When the drill member penetrates the bone, the projecting member receives the elastic force from the elastic spring in the insertion direction of the drill member, projects from the through hole, and moves to the non-engagement position where the rotational driving force is not transmitted to the drill member. The drill member stops rotating and the cutting function is lost. Therefore, after the through hole is formed, the drill member does not cut the bone and the surrounding tissue more than necessary, and safety is improved.

  In addition, the drill member has an engaged portion that protrudes radially inward from the inner peripheral surface, and the protruding member is an engaging portion that protrudes radially outward, and when in the engaged position, the protruding member It is good to have an engaging part which abuts with a to-be-engaged part by rotation of this, and rotates a drill member. By setting it as such a structure, the rotational drive force from a drive source can be transmitted to a drill member via a protrusion member with a simple structure.

  In addition, it is preferable that at least one of the engaging portion and the engaged portion is provided in plural. By providing a plurality of engaging portions and engaged portions, the engaging portions and the engaged portions are engaged at a plurality of locations, and transmission of the rotational driving force from the protruding member to the drill member is more reliably performed. Will be done.

  The protruding member protruding from the through hole may push up the mucous membrane on the back side of the bone in the insertion direction. When the protruding member pushes up the mucous membrane on the back side of the bone in the insertion direction, the distance between the drill member and the mucous membrane increases when the through hole is formed. Therefore, the risk that the mucous membrane is broken by the drill member can be reduced.

  Moreover, it is good for a protrusion member to have a control part which contacts the drill member in an insertion direction, and controls the protrusion amount which protrudes from a through-hole in the insertion direction. By regulating the protruding amount of the protruding member, the amount by which the protruding member pushes up the mucous membrane is adjusted, and the risk that the mucosa is broken by the protruding member can be reduced by pushing up more than necessary. Moreover, it can suppress that a protrusion member detach | leaves from the other structure of a medical drill completely, and when pulling out a drill member after forming a through-hole, it can prevent that a protrusion member remains in a human body.

The driving force transmission member has a column portion extending in the rotation axis direction, the projecting member has a fitting hole portion extending in the rotation axis direction to be fitted to the column portion, and the fitting hole portion and the column portion are In the fitted state, the driving force transmission member and the protruding member may rotate together. Thus, by having a column part and a fitting hole part, the protrusion member can be rotated and the structure which a protrusion member protrudes in a rotating shaft direction is realizable.

  As described above, according to the present invention, it is possible to provide a medical drill that forms a through-hole in a bone and suppresses the drill member from damaging tissue around the bone. . In particular, it is possible to provide a medical drill that suppresses breaking of the mucous membrane on the back side of the bone.

FIG. 1A is an exploded perspective view of an implant drill according to the present embodiment, and FIG. 1B is a diagram illustrating a combination of a driving force transmission member and a protruding member of the implant drill according to the present embodiment. FIG. 1C is a perspective view showing an overall configuration of the implant drill according to the present embodiment. FIG. 2A is a side view of the cylindrical drill member of the present embodiment, and FIG. 2B is a perspective view of the cylindrical drill member of the present embodiment and is a view seen through the inside. FIG. 3A is a side view of the protruding member of the present embodiment, and FIG. 3B is a perspective view of the protruding member of the present embodiment and is a view seen through the inside. FIG. 4A is a side view of the driving force transmission member of the present embodiment, and FIG. 4B is a perspective view of the driving force transmission member of the present embodiment and is a view seen through the inside. Fig.5 (a)-FIG.5 (c) are sectional drawings which show the state which the protrusion member 20 of the drill 100 for implants of a present Example protruded. 6 (a) and 6 (b) are cross-sectional views showing a state in which the protruding member of the implant drill of the present embodiment is in a position where the spring spring is compressed. FIGS. 7A to 7D are views showing the operation of the implant drill when forming a through hole in the maxillary bone. Fig.8 (a) is sectional drawing of the drill for implants which concerns on a modification, Comprising: It is sectional drawing which shows the state which the protrusion member compressed the spring spring. FIG.8 (b) is sectional drawing of the drill for implants which concerns on a modification, Comprising: It is sectional drawing which shows the state which the protrusion member protruded. FIG. 9 is a perspective view showing a state where the drive transmission member and the projecting member are coupled to each other, and is a diagram illustrating an example of the shape of the column portion and the fitting hole portion.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be exemplarily described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. Absent.

(Example)
<Overview of implant treatment and implant configuration>
First, an outline of an implant treatment and an implant configuration using an implant drill as a medical drill according to an embodiment of the present invention (hereinafter, this embodiment) will be described.

  The implant has a superstructure, a connection abutment (abutment), and an implant body (an artificial tooth root). The superstructure is a denture that substitutes for a so-called tooth, and the implant body is a portion that is embedded and fixed in the jaw bone. The connection abutment is a portion connecting the superstructure and the implant body, and plays a role of adjusting the orientation of the denture. As the implant of this example, an implant body having a diameter of 4.0 mm and a length of 9 mm is used.

  In this embodiment, an implant treatment in the case of an upper tooth, that is, in the case where an implant is provided in the maxillary bone will be described. First, an incision is made in the gum (gingiva) of the part where the tooth is lost and the implant is to be embedded, thereby exposing the maxillary bone. Then, a hole is made in the exposed bone using the implant drill of this embodiment. The implant body is embedded in the hole using a dedicated instrument. After the implant body is embedded in the hole, the incised gum is closed again and sewn firmly. Wait for the implant body to be fixed to the bone in this state (about 3 months). When the implant body is fixed to the bone, a denture as a superstructure is attached to the implant body via a connection abutment.

<Configuration of implant drill>
Next, with reference to FIGS. 1-4, the structure of the drill for implants of a present Example is demonstrated. FIG. 1A is an exploded perspective view of an implant drill 100 according to this embodiment, and FIG. 1B is a drive force transmission member 30 and a protruding member 20 of the implant drill 100 according to this embodiment. FIG. 1C is a perspective view showing a state in which the cylindrical drill member 10 is joined to the overall configuration of the implant drill 100 according to the present embodiment (FIG. 1B). FIG. FIG. 2A is a side view of the cylindrical drill member 10 of the present embodiment, and FIG. 2B is a perspective view of the cylindrical drill member 10 of the present embodiment, and is a view seen through the inside. is there. FIG. 3A is a side view of the protruding member 20 of the present embodiment, and FIG. 3B is a perspective view of the protruding member 20 of the present embodiment and is a view seen through the inside. FIG. 4A is a side view of the driving force transmission member 30 of the present embodiment, and FIG. 4B is a perspective view of the driving force transmission member 30 of the present embodiment and is a view seen through the inside. .

  The implant drill 100 according to the present embodiment mainly includes a cylindrical drill member 10 for cutting bone, a protruding member 20 provided on the inner peripheral side of the cylindrical drill member 10, and a cylindrical drill member via the protruding member 20. The driving force transmitting member 30 that transmits the rotational driving force to 10 is constituted by three members. Hereinafter, the configuration of each of these members will be described. The cylindrical drill member 10, the protruding member 20, and the driving force transmission member 30 are rotatable members. In the following description, a direction in which the cylindrical drill member 10 is inserted into the bone in the rotation axis direction is referred to as an insertion direction S.

<< Configuration of cylindrical drill >>
As shown in FIGS. 2A and 2B, the cylindrical drill member 10 includes a cylindrical drill main body 11 and an engaged portion 12. A tip blade 11 a is formed at one end of the cylindrical drill body 11 in the rotation axis direction. Although not shown, a groove is spirally formed on the outer peripheral surface of the drill body 11, and the edge of the groove forms an inner peripheral surface of the through hole by cutting bone. That is, the inner diameter of the through hole formed in the bone is substantially the same as the outer diameter of the drill main body 11. The drill body 11 is made of metal. Moreover, as shown in FIG.2 (b), the to-be-engaged part 12 protrudes radially inward from the internal peripheral surface of the drill main-body part 11, and the two are provided in the circumferential direction at equal intervals.

<< Configuration of protruding member >>
As shown in FIGS. 3A and 3B, the protruding member 20 has a protruding main body 21 and an engaging portion 22. The protruding main body 21 has a hollow (fitting hole 21b) inside, one end is open (opening 21c), and the other end is a rounded tip 21a. The diameter of the fitting hole 21b is the same at any position and is the same as the diameter d1 of the opening 21c. As shown in FIG. 3B, the engaging portions 22 protrude radially outward from the outer peripheral surface of the protruding main body portion 21, and two engaging portions 22 are provided at equal intervals in the circumferential direction. Here, the outer diameter of the locus of the engaging portion 22 when the projecting member 20 rotates is smaller than the inner diameter of the drill main body portion 11 of the cylindrical drill member 10, and the engagement when the cylindrical drill member 10 rotates. It is larger than the inner diameter of the locus of the joint portion 12. The protruding member 20 may be made of resin or the like, but is not limited thereto.

  As will be described later, the engaged portion 12 and the engaging portion 22 abut against the engaged portion 12 in the rotation direction as the engaging portion 22 rotates, and the cylindrical drill member is rotated with the rotation of the protruding member 20. If it is the structure which can carry 10 around, it will not be restricted to the shape and position which are shown in a present Example, and the number does not need to be two. For example, a configuration in which there is one engaging portion 22 and two engaged portions 12 may be employed. In the present embodiment, two engaging portions 22 and two engaged portions 12 are provided, with one engaging portion 22 abutting one engaged portion 12 and the other engaging portion 22 being the other. They were arranged so as to abut against the engaged portion 12 of the. With this configuration, the engaging portion 22 and the engaged portion 12 can be more reliably engaged, and the rotational driving force can be more reliably transmitted from the protruding member 20 to the cylindrical drill member 10. it can. Further, in the present embodiment, the engaging portion and the engaged portion are configured to protrude, but the present invention is not limited to this as long as these can be engaged with each other. For example, the engaging portion may be a convex portion protruding from the outer peripheral surface of the protruding member, and the engaged portion may be a concave portion formed on the inner peripheral surface of the cylindrical drill member.

<< Configuration of Driving Force Transmission Member >>
The driving force transmission member 30 extends in the direction of the rotation axis and is fitted to the fitting hole portion 21b of the protruding member 20, a drill holding portion 32 that holds the cylindrical drill member 10, and a driving force transmission portion. 33. The column portion 31 has a columnar shape, the diameter of the tip portion is d2a, and the diameter slightly increases as it approaches the end portion. The diameter d2a of the tip portion of the column portion 31 is substantially the same as the diameter of the opening portion 21c of the protruding member 20. Therefore, the diameter d2b of the column part 31 at a position approaching the end part by a predetermined distance from the tip part of the column part 31 is larger than the diameter of the opening part 21c of the protruding member 20. In a state in which the protruding member 20 is fitted to the column portion 31 to some extent (the state shown in FIG. 1B), a frictional force (circumferential force) between the inner peripheral surface of the protruding member 20 and the outer peripheral surface of the column member 31 ( Static friction force) works, and the protruding member 20 also rotates integrally with the column portion 31.

  The drill holding portion 32 includes a bottom surface portion 32 a and a cylindrical portion 32 b that extends from the bottom surface portion 32 a in the insertion direction S and holds the cylindrical drill member 10. In addition, the cylindrical portion 32b forms a stepped portion by the first cylindrical portion 32b1 and the second cylindrical portion 32b2 having a smaller diameter than the first cylindrical portion 32b1. In this embodiment, the outer diameter of the second cylindrical portion 32b2 and the inner diameter of the drill main body portion 11 are made substantially the same, and the outer diameter of the first cylindrical portion 32b1 and the outer diameter of the drill main body portion 11 are made substantially the same. When the drill main body 11 is put on the holding portion 32 (cylindrical portion 32), the end surface 32c of the second cylindrical portion 32b2 of the drill holding portion 32 and the end surface 11b of the drill main body portion 11 come into contact with each other.

  The driving force transmission portion 33 is provided on the back surface of the bottom surface portion 32a of the drill holding portion 32, engages with a driving source (not shown), and rotates the driving force transmission member 30. That is, when the driving force transmission unit 33 is rotationally driven, the column part 31 and the drill holding part 32 are rotationally driven. Here, the outer diameter of the second cylindrical portion 32b2 and the inner diameter of the drill main body portion 11 are substantially the same, and the outer peripheral surface of the second cylindrical portion 32b2 and the inner peripheral surface of the drill main body portion 11 slide with each other. Even if the force transmission member 30 rotates, the rotational driving force is not directly transmitted to the cylindrical drill member 10. As will be described later, the rotational driving force is transmitted from the driving force transmission member 30 to the cylindrical drill member 10 only through the protruding member 20. The cylindrical portion 32b of the driving force transmission member 30 is preferably configured to hold the cylindrical drill member 10 so that the cylindrical drill member 10 does not fall out in the insertion direction S. For example, the cylindrical portion 32b (second cylindrical portion 32b2) has an annular outward flange on the outer peripheral surface, an annular groove is formed on the inner peripheral surface of the cylindrical drill member 10, and the outward flange is a groove. The cylindrical portion 32b may be configured to restrict movement of the cylindrical drill member 10 in the insertion direction S by fitting.

Further, as shown in FIGS. 4A and 4B, a spring spring 34 is inserted into the column portion 31 as an elastic spring that can expand and contract in the direction of the rotation axis. The spring spring 34 may or may not be fixed to the bottom surface portion 32 a of the drill holding portion 32. The spring spring 34 is disposed so as to be compressed between the bottom surface portion 32a of the drill holding portion 32 and the end surface 21b of the protruding main body portion 21 of the protruding member 20 (see FIGS. 5 and 6).

<Transmission and release of rotational driving force of implant drill of this embodiment>
Next, with reference to FIG. 5, FIG. 6, transmission of the rotational driving force of the implant drill 100 of a present Example and cancellation | release are demonstrated. Fig.5 (a)-FIG.5 (c) are sectional drawings which show the state which the protrusion member 20 of the drill 100 for implants of a present Example protruded. FIG. 5C is a cross-sectional view showing the overall configuration of the implant drill 100, and FIG. 5A is a cross-sectional view of the protruding member 20 and is a cross-sectional view taken along line AA in FIG. FIG. 5B is a cross-sectional view of the cylindrical drill member 10 and is a cross-sectional view taken along the line BB of FIG. FIG. 6A and FIG. 6B are cross-sectional views showing a state in which the protruding member 20 of the implant drill 100 of the present embodiment is in a position where the spring spring is compressed. 6B is a cross-sectional view showing the overall configuration of the implant drill 100, and FIG. 6A is a cross-sectional view taken along the line CC in FIG. 6B. Hereinafter, the position of the protruding member 20 shown in FIG. 5 is defined as a disengaged position, and the position of the protruding member 20 illustrated in FIG. 6 is defined as an engaged position.

  In the state shown in FIG. 5, that is, in a state where the protruding member 20 protrudes from the tip blade 11 a of the cylindrical drill member 10 in the insertion direction S, the engaged portion 12 of the cylindrical drill member 10 and the engaging portion of the protruding member 20. 22 is displaced in the rotational axis direction. Therefore, even if the protruding member 20 rotates with the rotation of the driving force transmitting member 30, the engaging portion 22 does not abut against the engaged portion 12 in the rotating direction, and the rotational driving force is applied to the cylindrical drill member 10. Not transmitted. In the state shown in FIG. 5, the protruding member 20 is not sufficiently fitted to the column portion 31 of the driving force transmission member 30, so even if the driving force transmission member 30 rotates, it protrudes in the first place. The member 20 does not rotate. That is, the cylindrical drill member 10 does not rotate. Since the cylindrical drill member 10 does not rotate, the implant drill 100 is not in a state in which bone can be cut in the state shown in FIG.

  On the other hand, in the state shown in FIG. 6, that is, in a state where the projecting member 20 is pushed to the position where it does not project in the insertion direction S from the tip blade 11 a of the cylindrical drill member 10 while compressing the spring spring 34. The engaged portion 12 of the member 10 and the engaging portion 22 of the protruding member 20 are in positions that overlap in the rotation axis direction. Further, the protruding member 20 is sufficiently fitted into the column portion 31, and a frictional force acts between the inner peripheral surface of the protruding member 20 and the outer peripheral surface of the column portion 31, so that the driving force transmitting member 30 The projecting member 20 rotates with the rotation. When the projecting member 20 rotates in the direction of the arrow R shown in FIG. 6A with the rotation of the driving force transmitting member 30, the engaging portion 22 of the projecting member 20 rotates to the engaged portion 12 of the cylindrical drill member 10. Clash in the direction. The engaged portion 12 receives a force in the direction of the arrow R, and the engaged portion 12 rotates as the engaging portion 22 rotates. That is, the rotational driving force is transmitted from the driving force transmitting member 30 to the cylindrical drill member 10 (the engaged portion 12) via the protruding member 20 (engaging portion 22), and is cylindrical as the protruding member 20 rotates. The drill member 11 rotates. Since the cylindrical drill member 10 rotates, in the state shown in FIG. 6, the implant drill 100 is in a state in which bone can be cut.

In addition, in the present Example, although demonstrated using the cylindrical column part 31 with a circular cross section, and the fitting hole part 21b of the shape corresponding to it, it is not restricted to this. For example, the column portion may be a prismatic shape with a polygonal cross section, and the fitting hole portion of the protruding member may have a corresponding shape. Here, FIG. 9 is a perspective view showing a state in which the protruding member 20 and the drive transmission member 30 are coupled, and shows a perspective view of the column portion 31 and the fitting hole portion 21b as an example. As shown in FIG. 9, if the column portion 31 is a quadrangular column and the fitting hole portion 21 b also has a shape and size corresponding to it, the protruding member 20 is in relation to the column portion 31 in a state where they are fitted. Regardless of whether or not it is fully fitted, the column portion 31 and the protruding member 20 rotate integrally.

<Excellent point of implant drill of this example>
Next, the superior point of the implant drill 100 of the present embodiment will be described with reference to FIG. FIGS. 7A to 7D are views showing the operation of the implant drill 100 when a through hole is formed in the maxillary bone 50. FIG. 7A is a diagram illustrating a state before the tip blade 11a is abutted against the bone 50, and FIG. 7B is a diagram illustrating the state where the tip member 11a is abutted against the bone 50 and the protruding member 20 is pushed in. FIG. 7C is a diagram illustrating a state in which the tip blade 11a has entered the bone 50 while cutting the bone 50, and FIG. 7D is a diagram illustrating the tip blade 11a being a bone. 50 is a diagram illustrating a state in which the protruding member 20 protrudes through 50 and pushes up the mucous membrane 51 (Schneider membrane). In FIG. 7, for convenience of explanation, a side view of the implant drill 100 is shown, and a cross-sectional view of the bone 50 is shown.

  FIG. 7A shows a state similar to the state shown in FIG. 5C, in which the rotational driving force is not transmitted from the driving force transmission member 30 to the cylindrical drill member 10. From the state shown in FIG. 7A, first, the distal end portion 21 a of the protruding member 20 is abutted against the surface of the bone 50. When the tip blade 11a of the cylindrical drill member 10 is further pushed in the insertion direction S in the state where the tip portion 21a is abutted, the projecting member 20 is cylindrical while compressing the spring spring 34 in the direction opposite to the insertion direction S. The drill member 10 is pushed to a position where it does not protrude from the tip blade 11a, and moves to the engagement position. This state is shown in FIG.

  FIG. 7B is a state similar to the state shown in FIG. 6B, in which the rotational driving force is transmitted from the driving force transmission member 30 to the cylindrical drill member 10. The cylindrical drill member 10 rotates with the rotation of the driving force transmission member 30, so that the tip blade 11 a advances in the insertion direction S while cutting the bone 50. In the state where the tip blade 11a has entered the inside of the bone 50 while cutting the bone 50 as shown in FIG. 7C, the tip portion 21a of the protruding member 20 abuts against the bone 50, and the protruding member 20 is the tip blade. The state of being pushed into a position not protruding from 11a is maintained. That is, the state shown in FIG. 7C is also a state in which the rotational driving force is transmitted from the driving force transmission member 30 to the cylindrical drill member 10 as in the state shown in FIG.

  When the cylindrical drill member 10 is further advanced in the insertion direction S from the state shown in FIG. 7C, the cylindrical drill member 10 penetrates the bone 50. In the penetrated state, there is no bone 50 at the position where the tip 21a of the protruding member 20 abuts. Therefore, the protruding member 20 receives an elastic force (repulsive force) from the compressed spring spring 34 in the same direction as the insertion direction S, protrudes from the tip blade 11a, and moves to the non-engagement position. As described above, a frictional force is acting between the inner peripheral surface of the protruding main body portion 21 of the protruding member 20 and the outer peripheral surface of the column portion 31 of the driving force transmitting member 30, but in this embodiment, Used a spring spring 34 having an elastic force capable of pushing the protruding member 20 from the column portion 31 with a force stronger than the friction force.

  When the protruding member 20 protrudes, the positions of the engaged portion 12 of the cylindrical drill member 10 and the engaging portion 22 of the protruding member 20 in the rotational axis direction are shifted. Therefore, the transmission of the rotational driving force from the driving force transmission member 30 to the cylindrical drill member 10 via the protruding member 20 is released. Even if the transmission of the rotational driving force is released, the cylindrical drill member 10 continues to rotate due to inertia for a while, but then stops still. As described above, since the cutting function of the cylindrical drill member 10 is lost with the formation of the through hole in the bone 50, the risk of breaking the mucous membrane (Schneider's membrane) 51 on the back side of the maxillary bone 50 can be reduced. , Improve safety.

Further, due to the elastic force of the spring spring 34, the distal end portion 21a of the projecting member 20 projecting from the distal blade 11a in the same direction as the insertion direction S hits the mucous membrane 51 on the back side of the maxillary bone 50, and is shown in FIG. As shown, the mucous membrane 51 is pushed up. Thus, the cylindrical drill member 1
Since the mucous membrane 51 is pushed up in the insertion direction S by the protruding member 20 before the zero leading edge 11a reaches the mucous membrane 51, the risk that the leading edge 11a breaks the mucous membrane 51 can be reduced.

  In particular, when the above-described sinus lift method is employed, it is necessary to form a through hole in the maxillary bone 50. When the penetrating hole is penetrated, the cutting function of the cylindrical drill member 10 is lost, and the protruding member 20 becomes a mucous membrane 51. Therefore, it is possible to suppress the tip blade 11a from breaking through the mucous membrane 51 and the tip blade 11a from penetrating to the maxillary sinus 52.

  In the present embodiment, the case of cutting the maxillary bone 50 has been described with reference to FIG. 7. However, the present invention is not limited to this, and the case of cutting the mandibular bone is not limited thereto. A drill 100 may be used. In the present embodiment, the implant drill 100 has been described. However, the present invention is not limited to this, and other drills may be used as long as they are medical drills. For example, a skull craniotomy drill may be used. By using the medical drill of this embodiment, after forming the through hole, a medical accident such as damaging tissue around the bone is suppressed, and safety is improved.

(Modification)
Further, a modification of the present embodiment will be described with reference to FIG. FIG. 8A is a cross-sectional view of an implant drill 200 according to a modification, and is a cross-sectional view showing a state where the protruding member 120 compresses the spring spring 34. FIG. 8B is a cross-sectional view of the implant drill 200 according to the modification, and is a cross-sectional view showing a state in which the protruding member 120 protrudes. In addition, this example is an example which changed the structure of the protrusion member and the cylindrical drill member, and since it is the same as that of what was demonstrated using FIGS. 1-7 about the other structure, it is the same about the same member. The description thereof will be omitted using the reference numeral.

  In this example, as shown in FIG. 8, the outer diameter of the projecting main body 121 of the projecting member 120 becomes smaller as it approaches the front end 121a. Therefore, the projecting main body 121 is formed with an inclined surface 123 as a restricting portion. The inner diameter of the drill main body 111 on the tip blade 111 a side is configured to be smaller than the maximum diameter of the protruding main body 121 and larger than the minimum diameter of the protruding main body 121. With this configuration, when the protruding member 120 protrudes from the tip blade 111a due to the elastic force of the spring spring 34, the inclined surface 123 has a drill body portion of the cylindrical drill member 110 as shown in FIG. It hits 111 in the insertion direction S. That is, the inclined surface 123 restricts the amount of protrusion that the protruding member 120 protrudes from the through hole in the insertion direction.

  Thus, in the configuration of the modified example, the protruding amount of the protruding member 120 can be regulated, and the amount by which the protruding member 120 pushes up the mucous membrane on the back of the bone can be adjusted. Therefore, it is possible to reduce the risk that the protruding member 120 protrudes vigorously and breaks the mucous membrane. Moreover, it can suppress that the protrusion member 120 remove | separates completely from the other member of the drill 100 for implants. Therefore, when pulling out the cylindrical drill member 110 after forming the through hole, the risk that the protruding member 120 remains in the human body and the patient swallows it can be eliminated, and the safety of treatment is improved. To do. The restricting portion is not limited to the inclined surface 123 of the projecting member 120 as in the present example, and may be any one that impinges on the cylindrical drill member 110 in the insertion direction S and restricts the projecting amount of the projecting member 120. Other configurations may be used.

10, 110 Cylindrical drill member (drill member)
DESCRIPTION OF SYMBOLS 11, 111 Drill main-body part 11a, 111a Tip blade 12 Engagement part 20, 120 Projection member 21, 121 Projection main-body part 21a Tip part 21b Fitting hole part 22 Engagement part 123 Inclined surface (regulation part)
30 Driving force transmission member 31 Column portion 32 Drill holding portion 32a Bottom surface portion 32b Cylindrical portion 33 Driving force transmission portion 34 Spring spring (elastic spring)
50 Bone 51 Mucosa (Schneider membrane)
52 Maxillary Sinus 100 Implant Drill (Medical Drill)

That is, the medical drill of the present invention is
A medical drill for forming a through hole in a bone,
A cylindrical rotatable drill member;
A projecting member provided on the inner peripheral side of the drill member;
A driving force transmitting member for transmitting a rotational driving force from a driving source to the drill member via the protruding member, and rotating the drill member;
An elastic spring ,
The driving force transmission member has a column portion extending in the insertion direction, the projecting member has a fitting hole portion that is fitted to the column portion so as to be movable in the rotation axis direction, and the rotational driving force is the drive In the structure that is transmitted from the pillar part of the force transmission member to the protruding member,
The protruding member is
When the drill member cuts the bone, it engages with the drill member while transmitting the rotational driving force while compressing the elastic spring in a direction opposite to the insertion direction of the drill member while hitting the surface of the bone. Go to
When the drill member penetrates the bone, the elastic member receives an elastic force from the elastic spring in the insertion direction, protrudes from the through hole, and moves to a non-engagement position that does not transmit a rotational driving force to the drill member ;
The drill member has an engaged portion that protrudes radially inward from an inner peripheral surface, and the protruding member is an engaging portion that protrudes radially outward, and is in the engagement position, It has an engagement part which abuts in the rotation direction with respect to the to-be-engaged part by rotation of a projection member, and rotates the drill member .

In addition, the drill member has an engaged portion that protrudes radially inward from the inner peripheral surface, and the protruding member is an engaging portion that protrudes radially outward, and when in the engaged position, the protruding member rotated by the abutment in the direction of rotation with respect to the engaged portion, with the Turkey of having a engaging portion Tsuremawasu drill member, a simple configuration, through the projection member, the drill rotational driving force from a drive source Can be transmitted to the member.
Furthermore, the driving force transmission member has a column portion extending in the insertion direction, the projecting member has a fitting hole portion that is fitted to the column portion so as to be movable in the rotation axis direction, and the rotational driving force is Driving force transmission part
By adopting a configuration in which the projecting member is transmitted from the column portion of the material, it is possible to realize a configuration in which the projecting member can be rotated and the projecting member projects in the rotation axis direction.

Further, the restricting portion is configured by an inclined surface that becomes smaller as the outer diameter of the protruding main body portion approaches the distal end portion, and the drill member has an inner diameter on the tip blade side of the drill main body portion that is larger than the maximum diameter of the protruding main body portion. It can be configured to be small and larger than the minimum diameter of the protruding main body.

Claims (6)

A medical drill for forming a through hole in a bone,
A cylindrical rotatable drill member;
A projecting member provided on the inner peripheral side of the drill member;
A driving force transmitting member for transmitting a rotational driving force from a driving source to the drill member via the protruding member, and rotating the drill member;
An elastic spring,
Have
The protruding member is
When the drill member cuts the bone, it engages with the drill member while transmitting the rotational driving force while compressing the elastic spring in a direction opposite to the insertion direction of the drill member while hitting the surface of the bone. Go to
When the drill member penetrates the bone, the drill member receives an elastic force from the elastic spring in the insertion direction, protrudes from the through hole, and moves to a non-engagement position that does not transmit a rotational driving force to the drill member. Medical drill. The drill member has an engaged portion that protrudes radially inward from the inner peripheral surface,
The projecting member is an engaging portion projecting radially outward, and when in the engaged position, the projecting member hits the engaged portion in the rotational direction by the rotation of the projecting member, and rotates the drill member. The medical drill according to claim 1, further comprising an engaging portion.   The medical drill according to claim 2, wherein a plurality of at least one of the engaging portion and the engaged portion are provided.   The medical drill according to any one of claims 1 to 3, wherein the protruding member protruding from the through hole pushes up the mucous membrane on the back side of the bone in the insertion direction.   The said protrusion member has a control part which contacts the said drill member in the said insertion direction, and has a control part which controls the protrusion amount which protrudes from the said through-hole in the said insertion direction. The medical drill as described. The driving force transmission member has a column portion extending in the insertion direction,
The projecting member has a fitting hole portion that fits into the column portion,
6. The driving force transmission member and the protruding member rotate together in a state where the fitting hole portion and the column portion are fitted, 6. Medical drill.