JPS6016255B2 - Materials for restoring crown defects - Google Patents

Description

[Detailed description of the invention] The present invention relates to a material for restoring a tooth crown defect.

When restoring a decayed tooth with a large amount of decay in the crown using a covered crown, the missing part of the tooth is compensated for, and in order to maintain the replacement, a post is used as a restorative material, especially in the case of a non-vital tooth. Such a post consists of a spiral dowel as shown in Japanese Utility Model Publication No. 6-3047, and a punch body and head as shown in Japanese Utility Model Publication No. 51-29675, and the village body is made of stainless steel. It is known to have a dovetail thread and a constant cross-sectional area. Spiral dowels such as the one shown in Japanese Utility Model Publication No. 6-30475 are installed into the tooth root, but the dowel is rotated during installation, and the threads bite into the root dentin. It is troublesome and requires training in order to obtain the retention power.

In addition, an outward force is applied to the side wall of the insertion hole due to rotational force during installation, and since the spiral dowel has a conical shape, there is a high risk of causing a so-called imitation effect on the tooth root and causing the tooth root to break. On the other hand, if sufficient rotational force is not applied, the screw threads will not be sufficiently penetrated and sufficient retaining force will not be obtained, resulting in clinical problems.
This creates an extremely dangerous problem of the restoration falling off. Also,
In the case of a post that is equipped with a thread and has a constant cross-sectional area, as shown in Japanese Utility Model Publication No. 51-29675, when inserting the post into the tooth root, use a die and a tap in advance. Since the process is carried out in a rifling manner, the above-mentioned dangers are greatly reduced.

However, it is difficult to perform accurate rifling in the oral cavity.
In addition, training is required, and since the die and tap have a certain cross-sectional area, the hole is drilled outside the tooth root at the thinner part of the tooth root near the root line apex, and the periodontal tissue in contact with the tooth is drilled. It has been pointed out that there is a risk that this can lead to necrosis and even tooth extraction. In addition, in the above-mentioned post, the excess portion of the luting material that should be interposed between the post and the insertion hole wall must escape to the entrance of the insertion hole along the spiral shape, but the escape path is long and the luting material is Due to its viscosity, increased pressure is applied in the root direction, and there is a risk that the filling in the plate canal will escape from the root apex. When the crown collapse is large and it is necessary to enlarge the root canal and form a post insertion hole to maintain the restoration and insert the post, unlike when a pin is placed in the crown dentin, The thickness of the pin also increases, and the insertion hole must also be made larger. in this case,
If you use a pin whose cross section does not become narrower at the tip, as shown in Tokukan Sho 49-9083, the root of When forming a pin insertion hole in a tube,
There is a risk of perforation outside the tooth root and harming the periodontal tissue in contact with the tooth. Therefore, a post free of such drawbacks is desired. In addition, in recent years materials that have adhesive properties with tooth structure (carboxylic acid cement, glass ionomer,
adhesive composite resins, etc.) have been developed,
It is thought that if such a material is used as a luting material to fill the space between the tooth and the post, the post will be firmly fixed to the tooth, allowing for even more effective restoration.

However, when using such a luting material, no consideration has yet been given to the use of posts that pass through it. In view of the above-mentioned points, the inventors of the present invention have conducted extensive studies on materials for restoring tooth crown defects, particularly posts, and have arrived at the present invention.

The present invention is a material for restoring a tooth crown defect that includes a post as a component, and the post consists of a head 1 and a root canal insertion part 2, and the root canal insertion part has a circular cross section. It has a shape that becomes narrower at the tip, and the root canal insertion portion is provided with an escape path 3 through which an excess portion of the luting material applied in the root canal can overflow, and the root canal insertion portion is A plurality of independent grooves 4 or ridges 5 are provided along the circumference of the post for the adhesive to enter and fill the concave portion, and the head of the post is provided with a blade for fixing the construction. This is a repair material characterized by having a number 6 attached thereto. The restorative material of the present invention is composed of the above-mentioned posts,
Furthermore, a reamer for forming a post insertion hole in the tooth root and a bonding material for filling and adhering between the tooth and the post can be added as constituent elements. It is preferable that such a reamer has a shape that tapers at the tip and has a material diameter 0.01 to 0.5 larger in the diameter direction than the post. Posts and reamers are composed of multiple pieces of different sizes, and for each post with a different maximum diameter of the canal insertion part, the reamer has a rib diameter larger by 0.01 to 0.50 in the diametrical direction. are arranged. Further, as the bonding material, an adhesive resin having adhesive properties to the tooth substance is preferable. The post of the present invention will be explained in detail with reference to the drawings.

1, 2, and 3 are schematic diagrams showing an example of the post of the present invention. The post of the present invention is characterized in that the portion inserted into the root canal has a circular cross section and a shape that tapers at the tip. By adopting such a shape, the drawbacks of the post described in Japanese Utility Model Publication No. 51-29675 mentioned above are eliminated. That is, there is no possibility of perforation outside the tooth root in the narrowed part of the tooth root near the root apex, which would lead to necrosis of the periodontal tissue. The maximum diameter of the insertion part of the post of the present invention into the root canal is approximately 0.
．． 8-2. The length is about the length of a proboscis, and the diameter is narrower at the tip. Usually, a shape in which the diameter decreases toward the tip is adopted, but the shape is not necessarily limited to this, and the shape shown in FIG. 3 can also serve the purpose. Furthermore, the post of the present invention is characterized by the fact that a plurality of independent grooves 4 or ridges 5 are provided along the circumference of the inserted portion into the root canal for the adhesive to infiltrate and fill the concave portion. be. FIG. 1 shows an example of a post in which a crest 5 is provided on the insertion portion 2 into the pharyngeal tube, and FIG. 2 shows an example of a post in which a groove 4 is provided. The shape of the mountain or groove is
Although determined as appropriate, the height of the mountain is about 0.1 to 0.2 degrees, and the depth of the groove is about 0.1 to 0.2 degrees. These are roughly 2
It is preferable that a large number of them be provided at ~20 intervals and that they be parallel to each other. By providing the unevenness on the part inserted into the canal, when the post is inserted into the root canal, the glue fills the recessed part, and after the glue hardens, the post is firmly fixed in the root canal. be able to. Further, the post of the present invention is provided with an escape path 3 in the direction of the insertion portion into the root canal, through which an excess portion of the luting material applied in the root canal can easily overflow.

It is usually preferable to provide two to three such escape routes. Regarding the head, feathers 6 for fixing structures are attached to the head along the circumference of the head.

This increases the mechanical engagement between the post and the construction formed on the tooth, improving retention of the construction. Usually, the blades are arranged perpendicular to the axis of the head. The shape of the blade is appropriately selected to meet the above purpose, but is usually 0.5 to 2. It should be in the form of a plate with a thickness similar to that of a rib, with a thickness of 0.5 to 1. It is best to make the proboscis stick out. Such a blade may be formed in one piece along the circumference as shown in the figure, but may be divided into 2 to 5 pieces. It is preferable to provide two to four stages of blades on the head. The diameter and height of the head column may be approximately the same as those of conventionally known columns. Furthermore, the blades on the head and the peaks on the portion inserted into the root canal may have the same shape. Note that the post of the present invention can be easily manufactured by machining using materials such as stainless steel, copper alloy, and aluminum alloy. Before inserting the post of the present invention into a root canal, an insertion hole is first formed with a reamer. In the case of the post of the present invention, the insertion hole tapers toward the tip, so it is preferable to use a reamer with a tapered tip to form the insertion hole in this shape, and more preferably. It is preferable to use a reamer having a taper similar to that of the post.
In particular, when using the post of the present invention, it is very effective to use a reamer with a diameter 0.01 to 0.5 larger than the post. Furthermore, before using such a reamer, it is preferable to first enlarge the root canal using a reamer with a smaller diameter than this reamer, and then adjust the shape of the insertion portion using the reamer of the present invention with a larger diameter. The post of the present invention is not fixed to the dentin by screw engagement, but is fixed via a luting material filled between the dentin and the post, so the post can be easily inserted into the daughter canal. It is desirable to form an insertion hole large enough to be inserted into the hole. In addition, in order to ensure the distance between the post filled with glue and the insertion hole wall, a post provided with a protrusion 7 (Fig. 3) is used for convenience, and the protrusion at the tip of the post is inserted. By attaching it to the bottom of the hole, the distance between the post and the wall of the insertion hole can be reproducibly obtained. Therefore, a restorative material combining a post-reamer as described above is a preferred embodiment of the present invention. An example of the reamer used in the present invention is shown in the fourth example.
Although shown in the figure, except for the above-mentioned points, the knowledge regarding known reamers is directly applicable to the reamer of the present invention. After forming the insertion hole, the post is inserted. Insertion of the post is very quick and safe for the teeth since no threading is required in the teeth. When inserting the post, a luting material is injected into the insertion hole, and then the luting material is applied over the entire portion of the post inserted into the root canal, and the post is inserted into the insertion hole. At this time, since the post of the present invention is provided with an escape route through which the excess luting material can overflow as described above, the luting material (or plate filling material) is pushed out of the apical foramen. Never. By using such a luting agent, the luting material fills the gap between the tooth substance and the post in the root canal, and serves to strengthen the fixation between the tooth substance and the post. In the present invention, the binder used is a paste consisting of a fine filler, a monomer and a hardening agent, or a paste consisting of a fine filler and a polymer solution. Among them,
Preferably, it contains a component (monomer or polymer) that provides strong adhesion to tooth structure. Components that impart such adhesive strength include phosphoric acid ester monomers (particularly, JP-A No. 52-113089, 53-67740, 53
Preferred are monobasic acid phosphate ester monomers described in No. 69494 and the like. ), and an example of a luting material using this is 165 parts (parts by weight) of fine quartz powder.
, a dimethacrylate monomer (5 anchors) and the above-mentioned phosphate ester monomer (2 foundations) are added. Also,
Polymers having carboxyl groups (polyacrylic acid, etc.) also have adhesive properties to tooth structure, so cement containing such polymers (carboxylate cement, glass ionomer, composition example: 1.5 parts of zinc oxide, 50 parts of zinc oxide) % polyacrylic acid aqueous solution, 1.4 parts aluminosilicate glass, 1 part 50% polyacrylic acid aqueous solution, etc.) are also used as the bonding material. The aforementioned post,
A restorative material that combines such a luting material with a reamer is the most preferred embodiment of the present invention. After the cement has hardened, an abutment is constructed with a granular filling material (cement, amalgam, or composite resin), and the abutment preparation, impression, and crown fabrication are performed according to conventional methods. In this case, the blade provided at the head of the post of the present invention increases the mechanical coupling force between the post and the construction. As described above, by using the post of the present invention, there is no need to cut screws in the oral cavity.
In addition, since we use a reamer whose thickness gradually decreases toward the tip, there is no drilling outside the tooth root in the thinner part near the apex, and there is sufficient tooth substance left in the root. There is less risk of tooth root fracture.

This not only makes crown restoration very easy for the surgeon, but it is also safe for the tooth and surrounding tissues of the tooth plate, and there is no possibility that the tooth plate will break due to the excessive force after crown restoration. do not have. Furthermore, since the post of the present invention is provided with a groove or a mountain at the part inserted into the daughter pipe and a blade on the head, this increases the mechanical coupling force between the post and the joint, and between the post and the structure. I can't help it. In addition, by using a bonding layer that has adhesive properties to the tooth structure, the tooth structure and the bonding material are firmly bonded, and sufficient maintenance force for the post and the construction is provided. Furthermore, the groove provided in the direction from the tip to the head of the post prevents the luting material or the root filling material from being pushed out of the apical foramen when the post is inserted into the insertion hole. The axial groove also increases the resistance of the post to rotational forces. As described above, the post of the present invention is easy for the operator to operate, has little individual variation depending on the operator's technique, and enables crown restoration that is safe for the tooth and the surrounding tooth root tissue and that is robust and maintainable.

[Brief explanation of the drawing]

1, 2, and 3 are schematic diagrams showing an example of a post constituting the restorative material of the present invention, and FIG. 4 shows an example of a reamer constituting the restorative material of the present invention. It is a schematic diagram. 7 rhombuses, 2 rhombuses, 3 rhombuses, 4 hollyhocks

Claims (1)

[Scope of Claims] 1. A material for restoring a tooth crown defect that includes a post as a component, the post consisting of a head 1 and a root canal insertion portion 2, the root canal insertion portion having a cross section. has a circular shape that tapers at the distal end, and an escape passage 3 is provided at the insertion portion into the root canal to prevent excess luting material applied into the root canal from overflowing. A plurality of independent grooves 4 or ridges 5 are provided along the circumference of the insertion part for the luting material to infiltrate and fill the concave part, and the head of the post is for fixing the construction. A repair material characterized in that a blade 6 of the above is attached. 2. A material for restoring a tooth crown defect, which comprises a post and a reamer for forming an insertion hole for the post in the tooth root, wherein (a) the post has a head 1 and a root canal insertion part 2; The root canal insertion portion has a circular cross section and a shape that tapers at the tip, and the root canal insertion portion is designed to prevent excess luting material applied into the root canal from overflowing. A plurality of independent grooves 4 or ridges 5 are provided along the circumference of the inserted portion into the root canal for filling the concave portion with a luting material, and the head of the post A blade 6 for fixing the construction is attached to the reamer, and (b) the reamer has a shape that tapers at the tip and has a diameter of 0.01 mm with respect to the post.
A restorative material characterized in that the diameter is increased by ~0.50 mm. 3. A material for restoring a tooth crown defect, which comprises a post, a reamer for forming an insertion hole for the post in the root of the tooth, and a luting material for filling and bonding between the tooth and the post, (b) The post consists of a head 1 and a root canal insertion part 2, the root canal insertion part has a circular cross section and a shape that tapers at the tip, and the root canal insertion part has a An escape route 3 is provided through which an excess portion of the luting material applied within the canal can overflow, and an evacuation path 3 is provided to allow the luting material to infiltrate and fill the recessed portion along the circumference of the inserted portion into the root canal. A plurality of independent grooves 4 or peaks 5 are provided, and a blade 6 for fixing the construction is attached to the head of the post, (
b) The reamer has a shape that becomes narrower at the tip,
0.01 to 0.50 in the diametrical direction with respect to the post
A restorative material characterized in that the diameter is large in mm, and (c) the bonding material contains a monomer or polymer that has adhesive properties to tooth structure.