JPH0771563B2 - Method for producing artificial tooth root and artificial tooth root - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to improvement of titanium or titanium-based alloy implant materials, and relates to a method for producing an artificial tooth root and an artificial tooth root obtained from the method.

[Prior art]

Conventionally, in order to compensate for a missing tooth, it has been handled by bridging a denture to adjacent natural teeth, but in recent years, when there is a shortage of natural teeth, an implant method of permanently implanting an artificial root is adopted. It's starting. Ceramics and titanium-based alloys are used as the implant method. Titanium-based alloys have good compatibility with living organisms and are not harmful to living organisms, so that their use is expanding in recent years as an implant material. However, conventionally, it was manufactured by the lost wax casting method.

[Problems to be Solved by the Invention]

According to the lost wax casting method, it is necessary to prepare a mold according to the shape of the artificial tooth root, which compels production of a complicated mold, and has a drawback of requiring much labor and time. Further, since the molten metal is poured in, deterioration due to oxygen or heat is likely to occur, which may impair the physical properties. Further, impurities are likely to be mixed in during the manufacturing process, which may adversely affect biocompatibility. The present invention proposes a solution to these problems.

[Means for Solving the Problems]

The method of the present invention is characterized in that an artificial tooth root is cut and formed from a titanium or titanium alloy by rolling or a forged plate material by a wire cut electric discharge machining method of a numerical control program (CNC). As will be described later in detail in the section of action, the use of this wire-cut electric discharge machining method makes it possible to produce an excellent artificial tooth root product which has never been obtained. That is, it is an artificial dental root of titanium or titanium alloy having a head, a neck, and a leg, and the leg of the artificial dental root is cut and formed by wire-cut electric discharge machining as the uneven surface of 5 to 15 μm Rmax. Or an artificial root formed by cutting out and forming a plurality of artificial roots having a shape in which unit artificial roots having the same basic form as the artificial roots are continuously formed by wire cut electrical discharge machining. Alternatively, it is an artificial tooth root formed by cutting and molding by wire-cut electric discharge machining with wings attached to the lower part of the artificial tooth root. Further, by forming the leg portion by electric discharge machining, particularly wire cutting electric discharge machining, it is possible to give minute irregularities such as discharge marks to the surface extremely easily by setting conditions. In addition, by providing a through hole of 2 to 4 mmφ to this leg portion, by enlarging the contact area with the bone, adhesion with the tooth bone easily progresses, but the contact is strengthened,
If the through hole is 2 mmφ or less, the gripping area of the bone cannot be secured and the tooth root may come off, so a size of 2 mmφ or more is necessary. Even these through holes can be naturally provided with fine irregularities by wire-cut electric discharge machining. The reason why the head of the artificial tooth root is tapered is to facilitate the fitting of the crown, and the provision of the stopper at the boundary between the head and the neck is the initial stage of bone insertion of the artificial tooth root. This is to prevent the subsidence of Furthermore, by unitizing each of the same shapes, it is possible to appropriately make it continuous according to the embedding site and the shape of the tooth defect, and conversely, it is also possible to divide the continuous shape and use it as a single shape. On the other hand, if bone quality is poor, initial fixation is unstable, or there is anxiety in the occlusal relationship, the trabecular bone grows from the time of implantation by dividing the head and body into two. The most optimal treatment is to remove the head until the time when it grows, to prevent the occlusal pressure from being applied to the roots, and to apply the head secondly after the trabecular bone has grown firmly. Can be applied.

[Action]

Using the wire-cut electric discharge machining method of the present invention, good flexibility is obtained because of less metal deterioration and higher elongation as compared with the lost wax casting method, and a superstructure is provided during or after insertion. There is an advantage that there is little risk of breakage even when occlusal pressure is applied. In addition to this, since wire-cut electric discharge machining is high-density energy machining in ultrapure water, there is a secondary effect that the material is sterilized. Furthermore, the wire-cut electric discharge machining method is CNC machining, so it is easy to change the shape, size, etc. by a simple program modification, and a database of patients corresponding to a variety of needs can be created. There is an advantage that an optimal shape can be given and a better treatment is given. Regarding the artificial tooth root, since the surface of the leg portion becomes an uneven surface of 5 to 15 μm Rmax by the wire cut electric discharge machining, the adhesion with the bone becomes good. For the continuum of unit artificial tooth roots, the number of heads can be arbitrarily selected according to the implant site in the jawbone and the state of tooth loss. An artificial root with wings on the bottom of the head prevents the head from being buried and is highly stable. Machining according to these various requirements can be easily done by CNC wire cut electric discharge machining.

【Example】

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a front view (buccolingual view) of the artificial tooth root (implant) of the present invention, and FIGS. 2A and 2B are side views (mesiodistal view), respectively, which are preferable for mounting a prosthesis. The head 1, the neck 2, and the leg 3 which are tapered and have a truncated conical shape are integrally combined, and the number of the head 1 to be mounted on one leg 3 is arbitrarily selected. That is, the basic shape and pattern of the front view and the side view of the artificial tooth root of the present invention composed of the head 1, the neck 2, and the leg 3 are the same, but the size of each part is, for example, the dental implant. The number of heads 1, the vertical and horizontal dimensions of the head, neck, and legs, plate thickness (mesiodistal side diameter), etc. are changed and selected according to the insertion site and the state of tooth loss. It is something. However, this artificial tooth root is made of pure titanium or titanium alloy (for example, Ni-Ti alloy) about 1.2 to 2.5 mm thick rolled or forged plate material,
For example, Japanese Patent Publication Nos. 56-16007 and 55-468, such as one plate, one plate, or a desired number of plate materials laminated and integrated.
It is cut and formed into a predetermined shape and size by the numerical control (CNC) wire cut electric discharge machining method described in JP-A-06. Also, the vertical corners 3a of the legs 3
In the flat surface portion between the bottom portion 3b and the bottom portion 3b, as described above, through holes 3A of about 2 to 4 mmφ that strengthen the connection with the tooth bone after implantation are distributed and formed. It may be formed by processing, electrolytic processing, electron beam processing, laser beam processing, etc., for example, JP-A-56-69033.
If it is processed and formed by the electric discharge pore machining method as described in Japanese Patent Publication, the inner wall surface of the through hole 3A becomes a minute uneven surface of the electric discharge machining, the surface area increases, and the adhesive bond with the jawbone is improved. It is preferable because it is performed. When the artificial tooth root as shown in Figs. 1 and 2 is cut and formed from the plate material by wire cut electric discharge machining, the surface of the plate thickness portion on the outer peripheral side surface of the contour in the front view of Fig. 1 has the above-mentioned wire cut electric discharge. Although it becomes the machined surface, since both the front and back surfaces are rolled or forged flat surfaces, the second cut of the wire cut electric discharge machining as described in, for example, JP-A-56-9129 and JP-A-56-21733 is performed on both the front and back surfaces. By the machining method and the surface machining method by wire cut electric discharge machining described in the above-mentioned 59-88221, or the electric discharge machining by a normal forming electrode or a rod electrode for surface scanning machining, the above-mentioned front and back surfaces can be finely machined by electric discharge machining. It is preferable to process the uneven surface 3B. This minute uneven surface is
When wire-cut electric discharge machining is performed by connecting a capacitor of 5 to 30 μF to the gap, a crater-shaped electric discharge machining surface is obtained. Then, the concave portion of each crater on each crater-shaped electric discharge machined surface has a ratio D / H = 50 to 70, where D is the diameter and H is the depth, and a fine uneven shape that is preferable as the surface of the leg portion 3, Became dimensions. FIG. 3 is an example of a case where the artificial tooth root is made to be long in the head 1 side-by-side direction, for example, cut portions 3C such as cuts and perforations are provided at predetermined intervals, Part 1C with one head 1 according to the condition of internal implantation and tooth loss 3C-
The first and second parts 3C-2 and the three parts 3C-3 are appropriately selected and used. 4A and 4B are explanatory views of another embodiment. In the front view and the top view, the head 1 is set to the leg 3 and the neck when the bone quality is poor and the fixation is unstable, or when there is an anxiety element in the occlusal relationship. Fixed part integrated in 2
1B and an attachment / detachment portion 1A that can be attached / detached to / from the fixing portion 1B.The attachment / detachment portion 1A is removed until the trabecular bone grows when the artificial tooth root is embedded, and the occlusal pressure is buried. It is intended to prevent it from acting on the artificial tooth root. However, the mounting and fixing of the attaching / detaching portion 1A to the fixing portion 1B is attaching / detaching by fitting rotation of the fitting hole on the fixing portion 1B side and the fitting protrusion 1C on the attaching / detaching portion 1A side in the figure. For fixing, various shapes of fitting and fixing can be used, and also an adhesive can be shared, or mechanical connection such as a screw or welding can be used. The dashed-dotted line in FIG. 4A indicates the upper level of the jawbone 4. 5A and 5B are a partial perspective view and a perspective view of a state of use of an artificial dental root according to another embodiment. In the case where the bone is rough in the maxilla or the like, or when the artificial dental root is initially embedded in the bone. Interosseous wound 4D near the foundation of the head 1 to prevent subsidence and burial
An example is shown in which a wing-shaped object extending in a direction perpendicular to is formed as a stopper 1D in one or both of the perpendicular directions. This stopper 1D is, as shown in FIG. 5B, a tooth shoulder 4A.
It is also possible to prevent the subsidence or burial of the head 1 of the artificial tooth root by riding on the tooth shoulder 4A according to the interosseous wound 4B into which the artificial tooth root that has been treated is inserted. Next, Table 1 shows the results of the elongation test processed by the wire cut electric discharge method in comparison with the conventional die-cutting method. Casting Tensile strength Elongation Magnesia-based mold material 490-539Mpa 9.43% Phosphate-based mold material 509.6Mpa 2% As is clear from these results, wire-cut electrical discharge machining maintains the properties of metallic titanium even after machining. In the casting method, there is a tendency that the property of elongation is slightly deteriorated due to deterioration by oxygen in the air and heat and the brittleness against bending is somewhat increased. This is not preferable because cracking may occur when the artificial tooth root is curved with medical pliers or the like, but this method suppresses such deterioration of elongation. It should be noted that the physical properties of the cast material made of other materials are transcribed from the other data in the margins of Table 1 for comparison, and it can be seen that pure titanium is superior to these materials in terms of physical properties as an artificial tooth root. .

【The invention's effect】

As described above, the present invention utilizes wire-cut electric discharge machining to cut and form an artificial tooth root from a rolled or forged plate material of titanium or a titanium alloy, so compared with the case of a casting material such as lost wax, Since it is soft and stretchable, it is easy to bend and bend and is less likely to be damaged, and it is preferable because it does not deteriorate the physical properties of the material metal compared to the cast material. Because of this, there are advantages such as easy adhesion to the jawbone and strengthening. In addition, the method using wire-cut electric discharge machining according to the present invention can easily cope with the shape change by changing the NC program, which is also useful for reducing the manufacturing cost.

[Brief description of drawings]

FIG. 1 is a front view of the artificial dental root of the present invention viewed from the buccolingual side, and FIGS. 2A and 2B are side views viewed from the mesio-distal side. FIG. 3 is a front view of a series of the same type. FIG. 4A is a front view of an example in which the head and other parts are divided, and B is a plan view of the head. FIG. 5A is a partial perspective view of a lower part of the head provided with wings, and B is a perspective view showing a state where the wing is embedded in an interosseous wound. (1) Head, (1A) Detachable part (1B) Fixed part, (2) Neck part (3) Leg part, (3A) Through hole (3B) Micro uneven surface, (3C) Cut part (4) Jaw bone

Claims (4)

[Claims] 1. When manufacturing an artificial tooth root having a head portion, a neck portion and a leg portion, it is cut and formed from a rolled or forged plate material of titanium or titanium alloy by a wire cut electric discharge machining method of a numerical control program. Manufacturing method of artificial tooth root. 2. An artificial dental root of titanium or a titanium alloy having a head, a neck and a leg, wherein the leg of the artificial dental root has an uneven surface of 5 to 15 μm Rmax by wire cut electric discharge machining. An artificial tooth root formed by cutting and molding. 3. An artificial dental root of titanium or a titanium alloy having a head, a neck and a leg, which has a shape in which unit artificial roots having the same basic form as the artificial dental root are continuously formed. An artificial tooth root formed by cutting out and forming a plurality of artificial tooth roots that have the same by wire cut electric discharge machining. 4. An artificial dental root made of titanium or a titanium alloy having a head, a neck and a leg, the artificial root of which is provided with wings and cut and formed by wire cut electric discharge machining. Artificial tooth root.