JPH09308640A - Immediate type artificial dental root - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to restore occlusal force and beauty by implantation of an artificial tooth right after the extraction of the tooth without waiting for a restoration period by templating at least part of the dental root of the extracted tooth and manufacturing the artificial dental root. SOLUTION: A resin E, such as epoxy resin, is first put into a vessel and the extracted tooth T which is cut at its top and bottom and is subjected to a surface treatment is embedded as the male mold of the upper part of the artificial dental root into this resin. This tooth is removed after waiting for curing of the resin. The cavity formed after removal of the extracted tooth T has the same shape as the shape of the extracted tooth T. Next, a metallic cylinder C is previously aligned and placed in the safe and desirable direction where the bone quantity is the largest. An approximately cylindrical guide 10 is formed on the circumference of the cylinder C when an instant-set curing material, such as a cold-curing resin, is built up on the circumference and is cured. In succession, the metallic cylinder C is removed and the cavity bottom is bored with a hole of a depth of 5 to 6mm with the guide 10 as a guide. The guide 10 is thereafter removed and a plastic pattern 8 is inserted into the bored hole and wax W is packed in the upper part, into which a plastic pattern 9 is embedded.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an artificial tooth root (dental implant) used for dental treatment in the oral cavity of a living body.

[0002]

2. Description of the Related Art When a tooth lost due to various reasons is to be restored by an artificial tooth, an artificial tooth root (dental implant) can be embedded in a defective ridge and then reconstructed to reconstruct an upper structure. Has been done. Various artificial tooth roots have been proposed and are actually used, but bioactive ceramics such as hydroxyapatite having biocompatibility are used for the outer peripheral portion in contact with bone, and titanium etc. are used inside. A composite structure using a metal core having strength is known.

As an example thereof, a completely implantable artificial dental root described in Japanese Patent Laid-Open No. 60-135042 will be described with reference to the drawings. FIG. 9 is a cross-sectional view in the cheek-lingual direction showing a state in which an artificial tooth root is embedded,
FIG. 10 is a cross-sectional view in the buccolingual direction showing a state in which an upper structure is constructed on an embedded artificial tooth root. 1 is an artificial tooth root (implant), 2 is gingiva, 3 is a jaw bone, 4 is an abutment (abutment). ), 5 is a crown portion (crown).

First, the gingiva 2 at the site of implantation is incised to form an implant cavity in the jawbone 3 composed of the compact bone 3a and the cancellous bone 3b, and the artificial dental root 1 is embedded in the implant cavity. At the time of implantation, the upper surface of the artificial tooth root 1 is slightly protruded in the gingiva 2 from the bone edge of the jawbone 3, and then,
The incision of the gum 2 is sutured. In this way artificial tooth root 1
Completely embedded, when using hydroxyapatite sintered body etc. as an artificial tooth root, it takes about 2 times until bone tissue is bonded to the surface of the artificial tooth root and it can endure occlusion sufficiently.
Although it takes 3 to 3 months, during this period 1 artificial tooth root
Since the tooth itself is hidden in the gingiva 2, the occlusal pressure at the time of food mastication and the stress due to the tongue do not directly act on the artificial tooth root 1, so that the resting state can be maintained until the artificial tooth root 1 is completely fixed.

After the artificial tooth root 1 is completely fixed in the jawbone 3, the gingiva 2 is incised again to expose the upper surface of the artificial tooth root 1, and the artificial tooth root 1 is provided on the axis of the artificial tooth root 1 as shown in FIG. Screw the screw part of the tooth base 4 into the long hole to fix the tooth base 4,
The crown portion 5 is fitted and fixed to the tooth base 4 to construct an upper structure. As a result, bone adhesion occurs between the artificial tooth root 1 and the jawbone 3, and epithelial attachment occurs between the artificial tooth root 1 and the gingival 2 epithelium, so that an ideal artificial tooth that can sufficiently withstand the occlusal force can be realized.

As the artificial tooth root, a protrusion or an annular or spiral ridge is provided on the lower peripheral surface to promote the formation of new bone tissue and make the joint between the artificial tooth root and the jawbone more effective. Is common.

[0007]

By the way, the conventionally known artificial tooth root is a ready-made product although various sizes are prepared. On the other hand, the perforation of the jawbone (alveolar bone) minimizes the risk of damage to surrounding organs such as healthy adjacent teeth, arteries, and nerves, so that the direction of the tooth is correct and the future occlusal force is realized. It is desirable to make the size as small as possible.

When the tooth has been lost for a long period of time as in the above example, the gingiva of the tooth extraction cavity is recovered, so there are few problems, but when new tooth extraction is performed for various reasons, Since the conventional artificial tooth root does not have a shape that fits exactly into the tooth extraction cavity, it was necessary to leave it for about half a year after the tooth extraction to wait for the gingiva to recover, and then to implant a ready-made artificial tooth root.

However, the outer shape of the jawbone is maintained only after the teeth are functioning, and when the tooth is extracted, most of it is absorbed and atrophied during the healing process. Therefore, leaving it unattended for a long period of time is not only unfavorable for supporting the artificial tooth, but also has a bad influence such as occlusal failure and mental anxiety due to poor aesthetics. It is an object of the present invention to realize an artificial tooth root that eliminates the waiting for the recovery period and promptly embeds the artificial tooth after the tooth extraction to recover the occlusal force and the aesthetic appearance.

[0010]

SUMMARY OF THE INVENTION The present invention realizes an artificial tooth having a shape that fits exactly into the extraction socket by molding the shape of the extraction tooth itself taken out from the patient, and eliminates the waiting for the recovery period. It is an artificial tooth root. That is, the present invention according to claim 1 is an artificial tooth root characterized by being manufactured by molding at least a part of the tooth root portion of the extracted tooth.

According to a second aspect of the present invention, the root portion of the extracted tooth from which the lower end portion is removed is the upper male mold, and the rod-shaped body is arranged below the lower male mold to form the lower male mold in the female mold. The artificial tooth root according to claim 1, wherein the artificial tooth root is manufactured by casting metal. The present invention according to claim 3 is the artificial tooth root according to claim 1 or 2, wherein a tapered hole having a key portion near the center of the upper portion is formed.

The present invention according to claim 4 is characterized in that the instant hardening material is piled up in a female mold formed by arranging a rod-like body below the root portion of the extracted tooth from which the lower end portion is removed. It is a guide for piercing the jaw bone.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention is shown in FIGS.
This will be described below. FIG. 1A is a bucco-lingual cross-sectional view showing a state before extraction of a tooth to be treated, where T ₀ is the tooth, GL is the gingival margin, and BL is the bone margin. (B) is the extraction tooth T, T ₁
Is a crown portion, T ₂ is an upper root portion, T ₃ is a lower first root portion between GL and BL, T ₄ is a lower second root portion further below the lower root portion, and T ₅ is, for example, a diameter (minor axis) of 3 mm or less. It is the third lower part of the root. This dimension is 3 to 5 mm, depending on the diameter of the rod connected to the lower part, that is, the diameter of the hole drilled in the jawbone.
Should be selected in the range of

The extracted tooth T first has its upper and lower crown portions T ₁ and third lower root T ₅ removed by cutting. First place is to extraction of teeth bone mass of the support portion such as by pyorrhea is low, it is necessary make deeper implanted than extracted tooth T, further it in place of the root third lower T ₅ Need to extend. Next, a thickness of 500μ on the first lower root T ₃
Wrap tape etc. around. A surface treatment agent is applied to the second lower part of the root T ₄ to a thickness of about 200 μ, which corresponds to the periodontal ligament.

FIG. 2A shows a plastic pattern 8 to be used in the future, and FIG. 2B shows the same plastic pattern 9.
FIG. The plastic pattern 8 used as the male part of the lower part of the artificial tooth root is a rod-shaped body having a protrusion 81 on the surface, and the outer diameter of the protrusion corresponds to the diameter of the implant fossa piercing the jawbone. On the other hand, the plastic pattern 9 is used in a connecting portion for connecting the upper part of the artificial tooth root and the tooth base or the crown, and is frustoconical in shape, and the key portion 91 is formed at one upper end.

Next, one embodiment of the manufacturing process of the artificial tooth root of the present invention will be explained with reference to the conceptual diagram of FIG. First, as shown in (a), resin E such as epoxy is put in a container and
The extracted tooth (hereinafter simply referred to as extracted tooth) T, which has been surface-cut by cutting the upper and lower sides as described in (b), is used as a male mold on the upper part of the artificial tooth root so that the GL position becomes the liquid surface of the resin. Buried, wait for the resin to cure and remove it. The cavity formed by removing the extraction tooth T has the same shape as the extraction tooth T.

Next, as shown in (b), a metal cylinder C having a diameter of 3.25 mm, for example, is placed in the fossa from which the extraction tooth T has been removed, in a preferred direction with the greatest amount of bone and safe, and immediately around the periphery. When an instant hardening material such as heavy resin is piled up and hardened, a substantially cylindrical guide 10 is formed around the cylinder C. Subsequently, as shown in (c), the metal cylinder C is removed and the guide 10 is used as a guide, and a hole having a depth of 5 to 6 mm is made in the bottom of the fossa with a drill having a diameter of 3 mm, for example.

As shown in (d), the guide 10 is removed,
(This guide 10 is also used during treatment.) The plastic pattern 8 shown in FIG. 2A is inserted into the opened hole, and the wax W is filled above it.
The plastic pattern 9 shown in (b) is embedded. At this time, it is convenient to determine the direction of the key portion 91 of the plastic pattern 9 so that it faces the tongue side or the cheek side.

Although the plastic patterns 8 and 9 have been described as being separate, they may be integrated. However, it is convenient to keep them separate because they can be adjusted in either direction. With this, a female mold is completed, and thereafter, an artificial dental root is manufactured by casting metal such as titanium by a usual dental technique. At the time of casting, the plastic patterns 8 and 9 and the wax W are burnt or washed away and disappear.

FIG. 4 is a front view of the obtained artificial tooth root 1. The upper part 1a is a part formed by the extraction tooth T, as shown in FIG.
Of the extracted teeth T in (b), they correspond to T ₃ and T ₄ , and their upper edges correspond to the position of GL. The upper part 1a is about 500μ larger than the extraction tooth T when molding, but it is about
The thickness is reduced by 100μ, which is about 400μ larger than the extracted tooth T. A taper hole 1c having a key portion is formed by the plus rack pattern 9 near the center of the upper portion 1a. A perspective view of only the upper portion 1a is shown in FIG.

On the other hand, the lower portion 1b of the artificial tooth root 1 is a portion which is recessed in the jawbone and is shaped by the plastic pattern 8 in the present invention, but it has the same shape as a commercially available artificial tooth root. Bioactive ceramics such as hydroxyapatite is applied to the surfaces of the lower part and the lower part 1b of the upper part 1a. As an example, the method of manufacturing the artificial tooth root by molding the extracted tooth by casting has been described, but it is also possible to manufacture the artificial tooth root by various copying processes such as NC machining by a computer and wire electric discharge machining.

Next, a method of embedding an artificial tooth by the artificial tooth root will be described. After extracting the tooth, the extracted tooth is used to process the artificial tooth root as described above, while healing the inflammation for a while.
The guide 10 is inserted into the extraction socket after a week. The guide 10 is shown in FIG. At the stage of Fig. 3 (b), this guide is made larger by about 200μ by adding the thickness of the periodontal ligament to the shape of the extracted tooth, so it should fit snugly in the extraction socket. If it is difficult to enter, lightly trace the extraction socket with a bar. At this time, it is possible to judge the suitability of the artificial tooth root which is separately manufactured, depending on how the guide 10 is inserted.

Since the guide is provided with a 3.25 mm hole at the center, an implant fossa is drilled in the jawbone using this hole as a guide. Prior to surgery, it is important to perform a sufficient simulation using a model or radiograph. FIG.
As shown in (a), open the model in a state similar to that at the time of surgery, put the guide 10 on, insert a long rod B having a diameter of about 3 mm into the hole, and place the tip of which tooth of the anterior jaw. Then, the point P is recorded on the tooth, the plastic sheet S, or the like. At the time of operation, as shown in (b), a rod B is attached to the back surface of the drill D so as to be aligned with the rotation axis of the drill, and the tip of the rod B is drilled so as to correspond to the position recorded in the previous step. The positional relationship is accurately reproduced.

After perforating to a predetermined depth, the artificial tooth root is driven. The artificial tooth root of the present invention has an upper portion, that is, a gingival margin (G
L) Since the shapes of the following parts are matched with the extracted tooth originally located at that position, the extracted tooth root is almost completely blocked by the driven artificial tooth root. On the other hand, the upper structure attached above the artificial tooth root 1 is produced by a technician by reproducing the state of the oral cavity with a model. FIG. 6 is a perspective view showing the plastic pattern 7 for the upper structure. The plastic pattern 7 is put in the artificial tooth root 1 embedded in the patient's oral cavity to make an impression (molding). Transfer this plastic pattern 7 together with the impression material to a metal article 1A having the same shape as the upper part 1a of the artificial tooth root 1 shown in FIG. 5,
Gypsum is poured and hardened. After curing, the mold is removed and the artificial dental root in the oral cavity is transferred onto the model. Further, the plastic pattern 7 is appropriately scraped or wax is raised to finish the shape, and the upper structure is completed by casting by a usual method.

Since this upper structure is joined with the tapered hole (1c) in the upper part of the artificial tooth root via the key portion (91), the tooth rotation direction (direction) is more constant than in the conventional screw connection or pin connection. In addition, there is no problem such as height difference due to rotation, and the joining is extremely simple.

[0026]

According to the present invention, since a long recovery period is not provided, bone resorption after tooth extraction does not occur, and artificial teeth are immediately embedded to restore occlusal force and aesthetics. It has the excellent effect of being able to.

[Brief description of drawings]

FIG. 1A is a cross-sectional view in the cheek-lingual direction showing a state before tooth extraction in the present invention, and FIG. 1B is a front view of an extracted tooth.

FIG. 2 is a perspective view of a plastic pattern used in the present invention.

FIG. 3 is a conceptual diagram showing a manufacturing process of an artificial tooth root in the present invention.

FIG. 4 is a front view of an artificial tooth root according to the present invention.

FIG. 5 is a perspective view showing a part of an artificial tooth root according to the present invention.

FIG. 6 is a perspective view of a plastic pattern used in the present invention.

FIG. 7 is a perspective view of a guide used in the present invention.

FIG. 8 is a conceptual diagram showing the function of a guide in the present invention.

FIG. 9 is a cross-sectional view in the buccolingual direction of an artificial dental root showing a conventional technique.

FIG. 10 is a cross-sectional view of an artificial tooth in the cheek-lingual direction showing a conventional technique.

[Explanation of symbols]

 1 Artificial tooth root 1a Upper part 1b Lower part 1c Tapered hole 1A Hardware 2 Gingiva 3 Jaw bone 4 Tooth base part 5 Crown part 7, 8, 9 Plastic pattern 10 Guide B Rod C Metal cylinder D Drill S type plate T Teeth (extracting tooth) W wax

Claims (4)

[Claims] 1. An artificial tooth root, which is manufactured by molding at least a part of a tooth root portion of an extracted tooth (T). 2. The root part of the extracted tooth (T) from which the lower end portion has been removed is the male part of the upper part (1a), and the rod-like body (8) is arranged below it to mold it as the male part of the lower part (1b). The artificial tooth root according to claim 1, wherein the artificial tooth root is manufactured by casting metal in a female mold. 3. The artificial tooth root according to claim 1, wherein a tapered hole (1c) having a key portion (91) near the center of the upper portion (1a) is formed. 4. A guide for piercing a jawbone, characterized by being made by swelling an instant hardening material in a female mold formed by arranging a rod-like body below the tooth root portion of the extracted tooth from which the lower end portion has been removed.