JP4362606B2 - Manufacturing method of dental polishing tool - Google Patents

Description

  The present invention relates to a dental polishing tool used for grinding teeth in the oral cavity and grinding / polishing of a filling or prosthesis filled in the teeth.

  In the treatment of caries, a cavity (cavity) is usually shaved to form a cavity so that the filling can be easily packed. The formation of such a cavity is called cavity formation. When the cavity is formed, the cavity is filled with a filler made of metal or hard resin.

  When a defect occurs in a tooth in the oral cavity or surrounding tissue such as a tooth that has been touched, the lost form, function, and aesthetics are restored by covering with a metal. A material that compensates for a defect such as a metal to be covered is called a prosthesis.

  A dental polishing tool is used for forming the cavity and polishing the filler or prosthesis. In this dental polishing tool, a grindstone is fixed to the tip of a shank as a rotating shaft. The grindstone is made by pressure-molding silicon carbide (carborundum) abrasive grains or aluminum oxide (alumina) abrasive grains into a predetermined shape and sintering at a high temperature. A hole is drilled in the direction of the rotation axis from one end of the grindstone, and a shank is inserted into this hole and fixed with an adhesive. Here, the grindstone to which the shank is attached is referred to as a dental polishing tool, but this dental polishing tool is attached to a dental handpiece and used by rotating at high speed by an air turbine system or a micromotor system.

  However, such dental polishing tools are so hard that when used in the patient's mouth, not only fillings and prostheses, but also natural teeth adjacent to these restorations. There was an inconvenience of grinding together.

  Therefore, Patent Document 1 proposes reducing the hardness of the grindstone. By reducing the hardness, it is possible to fine-tune polishing materials that are soft in dental restorations, such as composite resin and silver amalgam to porcelain, which is a hard material, and prevent serious damage to natural teeth. Will be able to.

  FIGS. 5A and 5B are diagrams showing a bonding structure of a grindstone and a shank in the dental polishing tool 10 described in Patent Document 1, wherein FIG. 5A is a cross-sectional view, and FIG. 5B is a cross-sectional view taken along VV in FIG. It is. The grindstone 11 is a bottomed cylindrical shape with a closed tip, and a hole 12 is formed in the direction of the rotation axis, and a shank 13 is inserted into the hole 12. As the shank 13, stainless steel with little rust problem is used, and the tip 13 a inserted into the hole 12 has a small diameter.

  As the adhesive 15 for fixing the grindstone 11 and the shank 13, an epoxy adhesive or a molten metal is used. These adhesives 15 are in a viscous fluid state, and are adhered by being applied to the thin tip portion 13 a of the shank 13 and inserted into the hole 12 of the grindstone 11. The adhesive 15 is filled in the space S between the tip portion 13 a and the inner wall of the hole 12 of the grindstone 11.

  However, in the conventional bonding method, the adhesive 15 has a high viscosity, and the space S between the tip of the shank 13 and the hole 12 is filled with the adhesive as shown in FIG. It was easy to create no cavity c. These cavities c are also scattered in the space S shown in FIG.

  On the other hand, the grindstone 11 is rotating at a very high speed, and if there is a cavity c without the adhesive 15, the portion becomes light, so that a dynamic imbalance occurs during the rotation, causing uncomfortable vibration to the operator. There is a problem that fine polishing work cannot be performed.

Japanese Patent Laid-Open No. 9-117459, paragraphs 0003, 0006, 0011, FIG. 1, FIG.

  The present invention has been conceived from such circumstances, and an object of the present invention is to provide a dental polishing tool capable of accurately performing fine polishing work without giving unpleasant vibration during use and a method for manufacturing the same. To do.

In order to achieve the above object, a first invention of the present application is a dental polishing tool in which a bottomed hole formed in a grindstone and a shank without a step inserted in the hole are fixed with an adhesive. By applying a relative rotation between the shank and the grindstone during and / or after insertion of the tip of the shank into the hole of the grindstone, the adhesive is filled between the grindstone and the shank without any gaps, A part of the adhesive protrudes around the shank around the hole end face of the grindstone to form a ring-shaped adhesive part.

According to a second aspect of the present invention, there is provided a method for manufacturing a dental polishing tool in which a tip of a shank having no step on the outer periphery is inserted into a bottomed hole formed in a grindstone and fixed with an adhesive. a step of applying an adhesive to at least a portion of the bonding surface of said shank to impart relative rotation between the shank and the grindstone after insertion in and / or inserted into the hole of the grinding wheel, adhesive Filling the gap between the grindstone and the shank without leaving a gap, and making the part of the adhesive protrude into a ring shape.

  The adhesive between the hole formed in the grindstone and the tip of the shank inserted into the hole is used to bond and fix the shank and the grindstone, but there is a hollow portion that is not filled with adhesive. When it rotates at high speed, it causes vibration.

  Adhesive is applied to at least one of the hole in the grindstone and the tip of the shank, and when inserted while rotating between the grindstone and the tip of the shank, the adhesive fills the gap without creating a cavity. be able to. Then, it can be confirmed that an excess of the adhesive forms a ring-shaped adhesive portion on the inlet end face of the hole, and that no cavity is formed.

  If there is no cavity, the problem of imbalance is almost eliminated, and vibration does not occur even at high speed.

  According to the present invention, in the manufacture of a dental polishing tool, it is possible to prevent a cavity from being formed between the grindstone and the shank, and to suppress vibration due to dynamic unbalance during high-speed rotation, thereby performing fine polishing work. And an excellent dental polishing tool that is comfortable to use can be obtained.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
1-4 is a figure explaining the method to manufacture the dental polishing tool of this invention. The grindstone 11 is formed in the same manner as in the conventional example, and has a hole 12 extending along the rotation axis. An adhesive 15 is applied to the inner wall of the hole 12. This application method can be performed, for example, by attaching an adhesive 15 to the tip of a rod (not shown) thinner than the diameter of the hole 12 and inserting the rod into the hole 12. Moreover, it is not necessary to apply to the entire inner wall of the hole 12, and it may be halfway. As another method, the opening of the hole 12 may be directed upward, and the adhesive 15 may be poured from the opening.

  As shown in FIG. 1, the shank 13 may be inserted immediately after the adhesive 15 is applied to the inner wall of the hole 12, but as shown in FIG. 2, it is also suitable for the tip 13 a having a small diameter of the shank 13. The adhesive 15 may be applied by any method. This application does not need to be the entire tip portion 13a, and may be about ½ from the tip.

  As shown in FIGS. 1 and 2, when the adhesive 15 is applied to both the grindstone 11 and the shank 13, the shank 13 with the adhesive 15 is inserted into the hole 12 at the small-diameter tip portion 13 a shown in FIG. 2. . At this time, it is pushed in between the grindstone 11 and the shank 13 while giving a relative rotation in the left-right direction as shown. As a result, the adhesive 15 on the inlet side of the hole 12 is pushed by the distal end surface of the distal end portion 13 a and moves to the back of the hole 12. The space after the movement is filled with the adhesive 15 attached to the tip portion 13a. Since the relative rotation in the left-right direction is given between the tip portion 13a and the hole 12, the adhesive 15 spreads throughout the space S and does not form the cavity c. Moreover, since the sum total of the adhesive 15 applied in the hole 12 and the adhesive 15 applied to the tip portion 13a of the shank 13 is slightly larger than the volume of the space S, an excess amount from the entrance of the hole 12 The adhesive 15 protrudes to form a ring-shaped adhesive portion 15a as shown in FIGS.

  In addition, when inserting the shank 13 into the hole 12, relative rotation is given between the grindstone 11 and the shank 13, but in this case, the relative rotation may be given after insertion to the back. Alternatively, it may be inserted to the back while providing relative rotation, and further rotation may be given. The direction of rotation may be either one of the left and right directions or may be bidirectional.

  If the cavity c is formed in the space S, the adhesive does not protrude. Therefore, it can be confirmed that there is no cavity c by visually confirming that the ring-shaped adhesive portion 15a is formed.

  The amount of the adhesive 15 applied in the hole 12 and the amount of the adhesive 15 applied to the tip 13a of the shank 13 are trials so that a ring-shaped adhesive portion 15a having an appropriate size can be formed. It will be decided by an error method. Moreover, as a kind of the adhesive 15, it is preferable to use a phenol-based adhesive having high hardness and low thermal expansion.

  If the cavity c is not formed, the problem of dynamic imbalance is almost solved, and a dental polishing tool without vibration can be obtained.

It is sectional drawing of a grindstone. It is a figure of the front-end | tip part of a shank. It is sectional drawing which shows the state which inserted the shank in the grindstone. It is IV-IV sectional drawing of FIG. It is a figure which shows the coupling structure of the conventional grindstone and a shank, (a) is sectional drawing, (b) is VV sectional drawing of (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Dental polisher 11 Grinding stone 12 Hole 13 Shank 13a Tip part 15 Adhesive 15a Ring-shaped adhesive part c Cavity S Space

Claims (2)

In dental grinding tool which is fixed a shank with no stage inserted outer periphery each hole with a bottom formed in the grinding wheel with an adhesive, in inserting the distal end portion of the shank into the hole of the grinding wheel and / or by imparting relative rotation between the shank and the grindstone after insertion, the adhesive is filled without gaps between the shank and the grinding wheel, the adhesive on the shank periphery of the hole end surface of the grinding wheel A dental polishing tool characterized in that a part of the protrusion protrudes to form a ring-shaped adhesive part. The distal end portion of the no stage outer peripheral shank inserted into the hole with a bottom formed in the grinding wheel, in the manufacturing method of a dental grinding tool which is fixed by an adhesive, at least one and in grinding holes in the joint surface of the shank A step of applying an adhesive to the portion, and applying a relative rotation between the shank and the grindstone during and / or after the shank is inserted into the hole of the grindstone, and the adhesive is applied to the grindstone and the shank. A method of manufacturing a dental polishing tool, comprising: a step of filling the adhesive without gaps and setting a part of the adhesive protruding in a ring shape.

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