FR2589350A1 - STEM FOR DENTAL TREATMENT BY IMPLANTATION IN THE BONE - Google Patents

Abstract

THE INVENTION RELATES TO A ROD FOR DENTAL TREATMENT BY IMPLANTATION OF A TOOTH IN THE MAXILLARY. ACCORDING TO THE INVENTION, A METAL CORE 12 IS COATED ON A PORTION OF END 12B WITH HYDROXYAPATITE 13, CA (PO) (OH), AND PRESSED INTO THE MAXILLARY. THE OTHER END 12A IS CEMENT IN THE TOOTH ROOT CHANNEL.

Description

The present invention relates to a rod for dental treatment at

  use in an implantation process

in the tooth and in the bone.

  The tooth and bone implantation method is a dental treatment for maintaining and stabilizing a tooth moving by insertion of a shaft extending from the inside of the oscillating tooth into the tooth. 'bone. The method is applied to maintain and stabilize a fluttering tooth due to peripheral marginal tooth disease and to stabilize a tooth that has been shortened because its root has broken or because

  the end of its root has been cut off.

  Since a metal rod is conventionally used as a dental treatment rod for use in the tooth and bone implantation process, unavoidable problems such as rod corrosion and ion elution have been encountered. metal in the body. So we search

  more suitable materials for the stem.

  Recently, a dental treatment rod made of monocrystalline alumina has been developed and used because it is physically and chemically stable and has good affinity.

for the body.

  This mono-alumina dental treatment rod

  crystalline, however, does not yet have sufficient affinity for the organism. The monocrystalline alumina rod can become brittle, compared to a metal rod, so that the rod is likely to have insufficient resistance to a violent impact. It is an object of the present invention to solve the above problems of the prior art and to provide a dental treatment rod which has good affinity for the body and has sufficient resistance against violent impact.

  The invention can be summarized as a milking rod

  A hydroxyapatite, Ca10 (PO4) 6 (OH) 2, which has the same components as human bone and thus has an increased affinity for human tissue, is a dental matrix of a metal that is coated at one end. The invention will be better understood on reading the

  description which will follow with reference to the accompanying drawings in

  which: - Figure 1 is a partially exploded section showing an embodiment of the rod for dental treatment according to the present invention; Figure 2 is a cross section along the line II-II of Figure 1; FIG. 3 is a partially exploded sectional view showing another embodiment of the rod for dental treatment according to the present invention; and - Figure 4 is a cross section

  example of use of the stem for treatment

  dental system according to the present invention.

  The present invention has been obtained by seeking the use of hydroxyapatite, Ca10 (PO4) 6 (OH) 2, which is composed of the same components as human bone, to increase affinity

  a dental treatment rod for the body. The hydroxy

  apatite is applied to a metal core that has a resistance

higher.

  In other words, the dental treatment rod according to the present invention is characterized in that a portion of predetermined length from one end of a core of material

  metal is coated with hydroxyapatite.

  Accordingly, when the dental treatment rod is used in an implantation process in the tooth and in the bone, the metal portion is placed inside the tooth and attached to the tooth by a cement. The portion of the hydroxyapatite coated dental stem protrudes from the root of the tooth to be placed within the bone. As a result, the portion coated with hydroxyapatite is in direct association with the peripheral tissues

  because of its affinity for the organism and fixed with them.

  Thus, an oscillating tooth, or the like, having a defect in the portion of its root can be safely maintained and stabilized. The core material is a metal having a higher rigidity, compared to that of ceramics or similar materials so that it has the advantage that sufficient strength can be obtained even against a violent impact. In addition, the implementation such as cutting or the like, if necessary, can

be easily implemented.

  Figures 1 and 2 show an embodiment of a dental treatment rod according to the invention. A dental treatment rod 11 comprises a core material 12 made of steel, for example a titanium stainless steel. The core material 12 is of substantially circular cross section and comprises a step 12d between two end portions 12a and 12b so that the end portion 12b has a smaller diameter than the end portion 12a. The reduced diameter end portion 12b is coated with a coating material 13 consisting of hydroxyapatite. The coating material 13 is formed by applying hydroxyapatite by vacuum projection,

  cathodic projection, plasma spraying, etc. Preferably

  the thickness of the coating material is chosen between

  about 10 pm and 1 mm. The total length of the treatment rod

  Dental tooth 11 is chosen between 20 and 30 mm; the length b of the portion coated with the coating material is chosen between 10 and 20 mm; and the diameter c of the end portion 12a is selected between 0.5 and 2.5 mm. The diameter d of the smaller end portion 12b is about 0.2 to 0.3 mm less than that of the larger end portion c. The rod 11 generally has a slightly tapered shape. The above ranges of lengths a and b and diameters c and d are appropriate when considering the lengths and dimensions of normal teeth

  and there may be inconvenience to manipulation or difficulty

  cured in the treatment if the lengths and diameters of the

  stem are external to the ranges mentioned above.

  Now described below with reference to the

  Figure 4, an example of use of the dental treatment rod 11.

  In Figure 4, the shaft 11 for dental treatment is partially covered by a hydroxyapatite coating material 13. The stem 11 is applied to a defect portion of bone A in the gum B containing the porous hydroxyapatite

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  granulate C in a fibrin paste D near the maxillary E on a commitment portion F embedded in the maxillary E. A cyst G exists on the contact portion below the portion H in contact with the canal in the root in the area to be filled with fibrin paste D and hydroxyapatite 0. A portion I external to the gum defines the end of the gum B below

  portion J of maintaining the base of the tooth.

  First, the cyst G is completely removed from the maxilla

  E. The operated part becomes the defect portion of bone A. Then, the root canal is enlarged with a reamer at one end.

  diameter of 1.8 mm and the inside of the root canal is sufficient

  irrigated and disinfected. The rod 11 is first inserted into the root canal to confirm the conditions. Then, a carboxylate cement is applied to the rod 11 in the portion H in contact in the root canal. At the same time, we withdraw

  excess cement adhering to the hydroxide coating portion 13

  apatite. The rod 11 is inserted again inside the root canal and entrained in the maxilla E using a hemostatic chisel and a mallet. The defect portion of bone A is filled with a mixture of granulated hydroxyapatite C and fibrin and thrombin is added to form the fibrin paste D to bind thereto granulated hydroxyapatite C.

  Then, we sew the gum B to complete the operation. As a result

  In this case, the engagement portion F of the rod 11 embedded in the maxilla is placed inside the maxilla E. The portion G in contact with the cyst is placed inside the bone defect portion A, the portion H in contact in the root canal is placed inside the root canal and the support portion J of the tooth base is placed at a portion corresponding to a crown. Thus, when the stem 11 has been inserted into the tooth and the bone, the granulated hydroxyapatite C in the cyst, the hydroxyapatite coating portion 13 of the stem 11 and a newly formed bone are chemically bonded to each other in one while producing a powerful fastening force. On the other hand, since they are made of a metallic material, the portion H in contact with the root canal and the support portion J of

  the tooth base have sufficient strength and workability.

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  Figure 3 represents another mode of implementation

  of the dental treatment rod according to the present invention.

  In the dental treatment rod 11 of this embodiment, annular grooves 12c are formed at the outer periphery of an end portion 12a of a core material 12 on which the metal is exposed. The portion 12b coated with the hydroxyapatite coating material 13 is slightly tapered toward its front end portion 12e. In this rod 11, the fixing by the cement in the interior is made stronger. FIG. 4 represents the dental stem 11 of FIG. 3 in its final disposition with respect to a tooth K, to the gingiva B and to the maxillary E. The arrangement illustrated also applies to the dental stem of FIG.

Figure 2.

  Although the shaft 11 has been illustrated as a round section bar in each of the aforementioned embodiments, the shaft 11 may be of square cross-section in its entirety. In addition, although the rod 11 has been shown as tapered toward its end in each of the above embodiments, it is not always necessary to taper.

the stem.

  According to the present invention, as described above, one of the end portions of the metal core material is

  coated with hydroxyapatite so as to fix the metal

  exposed portion of the tooth and placing the hydroxyapatite-coated portion inside the bone, so that the coated portion and the bone tissue are firmly connected to each other due to the affinity of the hydroxyapatite for living tissue. It is therefore possible to maintain the tooth in a fixed manner. In addition, since the portion embedded in the bone tissue is coated with hydroxyapatite, there are no problems of corrosion, elution of metal ions, etc. in the body. In addition, since the core material is made of a metal having a higher rigidity, it is possible to obtain sufficient strength.

  against a violent shock and good workability.

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  It is understood that the invention is not limited to

  preferred embodiments described above as illustrative

  and that the person skilled in the art may make various modifications and changes thereto without departing from the scope and spirit of the invention.

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Claims (7)

  1. Dental treatment rod for fixing a tooth in a bone, characterized in that it comprises:   an elongate metal core (12) in contact with the interior   laughter of the tooth; and - a hydroxyapatite coating (13) on the surface of said   metal core (12) in contact with the bone.   2. Dental treatment rod according to claim 1, characterized in that the hydroxyapatite coating (13) covers a first end portion (12b) of predetermined length (b) of said rod and is in contact with said bone and in that   second end portion (12a) of said rod without said cover   hydroxoapatite is in contact with said tooth.   3. Dental treatment rod according to claim 2, characterized in that said rod has a circular cross section with a diameter of 1.5 to 2.5 mm, a total length (a) of 20-30 mm and said first end portion (12b) covered by said   hydroxyapatite (13) has a length (b) of 10-20 mm.   4. Dental treatment rod according to claim 2, characterized in that said first end portion is tapered towards its free end.   5. dental treatment rod according to claim 3, characterized in that said first end portion is   tapered towards its free end.   6. dental treatment rod according to claim 2, characterized in that said first end portion comprises   a series of continuous peripheral grooves (12c).   7. dental treatment rod according to claim 2, characterized in that it further comprises a step (12d) between said first and second end portions of said metal 0.2-0.3 mm, said first portion of end having a section   right smaller than said second end portion.