CN112453828A

CN112453828A - Multilayer root canal file and processing technology thereof

Info

Publication number: CN112453828A
Application number: CN202010262897.0A
Authority: CN
Inventors: 黄兵民; 刘晶; 向义
Original assignee: Jiangsu Shengmate New Material Technology Co ltd
Current assignee: Jiangsu Shengmate New Material Technology Co ltd
Priority date: 2020-04-02
Filing date: 2020-04-02
Publication date: 2021-03-09

Abstract

According to the multilayer root canal file and the processing technology thereof, the metal pipes are wrapped outside the core rod layer by layer, a certain margin is reserved among the metal pipes, and then the core rod and the metal pipes are integrally drawn and annealed to prepare the base material tightly wrapped by the metal pipes and the metal rods. The file body made of the base material has the characteristics of no untwisting, no blocking, no fracture and good structural stability under the action of external torsional stress. The invention directly carries out material reduction processing on each layer of metal pipe from outside to inside to manufacture the file body with the step-shaped working surface. The edge of the working surface of the file body can be manufactured into a circumferential ridge with a certain shape, such as an arc shape or a tooth shape, according to the specific function to be realized while reducing the material. The end of the working surface far away from the handle can be made into an outward-opening brush wire or skirt edge, so that the root canal file has the function of cleaning residues besides the grinding function.

Description

Multilayer root canal file and processing technology thereof

Technical Field

The invention relates to the field of medical instruments, in particular to a multi-layer root canal file which can not be unscrewed, stuck and broken during high-speed rotation and a processing technology thereof.

Background

The machine-used titanium-nickel alloy root canal file appears in the last 90 th century, and is popularized and applied in China around 2010, so that the level and efficiency of root canal treatment in the department of oral medicine are greatly improved. Particularly in the preparation of complex and fine root canals, it has significant advantages over conventional stainless steel root canal files. Compared with a stainless steel file body, the nickel-titanium alloy file body has the characteristics of good elasticity, low hardness, good flexibility and the like, can complete the preparation of the root canal in a shorter time, and simultaneously avoids excessive cutting of dentin in the root canal, thereby being deeply favored by oral clinicians.

At present, most of nickel-titanium alloy root canal files sold above adopt the modes of twisting, grinding, chemical treatment and the like, a file body is in a single-strand conical shape with threads, and the cross section of the file body is in a triangular shape, a rectangular shape and the like with a protruding part. In the root canal therapy art, the file body of root canal file is high-speed rotatory to the heart in patient's root canal under root canal motor's drive, and the protruding portion of the file body produces the cutting to the root canal wall at rotatory in-process to realize the effect of efficient clean and preparation root canal, beat the basis for the root canal therapy step on next step. Then, since the rotational trajectory of the file body is circular and most root canals have an oval or fissure-shaped cross-sectional configuration, it is difficult for the conventional nickel-titanium file to sufficiently clean the edges of the root canal.

To enhance the grinding of dentin in a root canal during an endodontic procedure, or to adequately clean the root canal area, capture loose debris and carry it out of the canal, threads are formed on the file surface by grinding or twisting to create a rough surface texture. However, since the single-strand file is fragile, the file is easily broken at the middle part during high-speed rotation, and the broken file remains in the root canal, so that the treatment effect cannot be achieved, and foreign matter which is difficult to clean is introduced into the root canal.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a processing technology for sleeving a plurality of layers of metal pipes outside a core rod, tightly wrapping the metal pipes and the core rod in an integrated drawing and annealing mode, reducing the metal pipes layer by layer, and making a file body into a conical multi-layer root canal file with a step-shaped working surface outside, and the multi-layer root canal file made by the processing technology.

The technical scheme of the invention is as follows:

a process for preparing multi-layer root canal file includes the following steps:

s1, manufacturing a plurality of metal pipes, wherein the difference between the inner diameter of the outer layer metal pipe and the outer diameter of the inner layer metal pipe is 0.005-0.5 mm;

s2, manufacturing a base material with a multilayer structure, sequentially sleeving a plurality of metal tubes outside a core rod to form a multilayer tube, and integrally drawing and annealing the multilayer tube to enable the multilayer metal tubes to form a tight package outside the metal rod;

s3 cold-drawing the substrate until its diameter is greater than or equal to the largest diameter of the file;

s4, performing material reducing processing on the file body of the base material to enable the removed part of the outer layer metal pipe to be more than the removed part of the adjacent inner layer, wherein the difference of the material reducing of the two adjacent layers of metal pipes is the axial length of the working surface on the inner layer metal pipe, and so on, the exposed working surface is distributed in a step shape, and the appearance of the file body is in a conical shape;

s5, carving on the outer surface of the working face, and/or cutting long strips on the part of the working face far away from the handle along the axial direction to form the brush filaments or the skirt which are outwards opened.

The length of substrate equals the finished length of root canal file, divide into file body and handle two parts with the substrate, subtracts material processing to file body and handle.

The length of the base material is equal to that of the file body, the file body and the handle are respectively processed, and then the file body and the handle are connected together through an interference fit or welding method.

In step S4, the edge of the working surface is a smooth wavy line or a zigzag broken line.

In the step S5, the engraved shape is a rectangle, a triangle, a polygon or an irregular shape.

In step S5, the engraved shape is a thread or a broken line extending continuously along the surface of the file body.

A multi-layer root canal file manufactured by the process is characterized in that: the novel file comprises a file body and a handle which are connected with each other, wherein the file body comprises a core rod, a plurality of layers of metal pipes and a working surface, and the plurality of layers of metal pipes are sleeved outside the core rod layer by layer from inside to outside to form a tight package; the length of the outer layer metal pipe is shorter than that of the adjacent inner layer, and the difference of the lengths of the two adjacent layers of metal pipes is the axial length of the upper working surface of the inner layer metal pipe; the working surface is distributed in a step shape, and the appearance of the file body is conical; the working surface is provided with a carved shape, or a slender strip is cut at the part of the working surface, which is far away from the handle, along the axial direction of the file body, so that brush filaments which are outwards opened are formed.

The file body and the handle are integrally formed.

The file body and the handle are different parts and are connected in an interference fit or welding mode.

The invention has the following technical effects:

according to the multilayer root canal file processing technology, the metal pipes are wrapped outside the core rod layer by layer, a certain margin is reserved among the metal pipes, and then the core rod and the metal pipes are integrally drawn and annealed to manufacture the base material with the metal pipes and the metal rods tightly wrapped. The file body made of the base material has the characteristics of no untwisting, no blocking, no fracture and good structural stability under the action of external torsional stress.

According to the invention, the material reduction processing is directly carried out on each layer of metal pipes from outside to inside by utilizing the characteristic of the tubular distribution of the metal pipes on the substrate, the material reduction of the external metal pipes is larger than that of the internal metal pipes, and the file body with the stepped working surface is manufactured. The edge of the working surface of the file body can be manufactured into a circumferential ridge with a certain shape such as an arc shape or a tooth shape according to a specific function to be realized while reducing the material, and compared with the prior art, the edge of the working surface of the file body directly processes a solid section, at least one processing procedure is omitted.

The end of the working surface far away from the handle can be made into an outward-opened brush wire or skirt, so that the root canal file has the function of cleaning residues besides the grinding function, and compared with the method of additionally filling metal wires or fibers in the prior art, the brush wire or skirt is integrated with the file body and is not easy to fall off in the working process.

Drawings

FIG. 1 is a schematic view of a multi-layer file structure of the present invention

FIG. 2, FIG. 3, and FIG. 4 are schematic diagrams of the engraving pattern on the working surface

FIG. 5 is a schematic view of a single metal tube

FIG. 6 is a schematic view of a mandrel being inserted into a metal tube

FIG. 7 is a schematic view of multiple layers of metal tubing being sleeved together

FIG. 8 shows a base material after integral drawing, annealing and cold-drawing

FIG. 9 is a view illustrating a process of reducing the material of the file body

FIG. 10 is a view showing a file body and a handle formed by integral molding

FIG. 11 is a schematic view of a file body and a handle manufactured by separately manufacturing and then connecting them

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments.

Example 1:

as shown in figure 1, the multi-layer root canal file of the invention comprises a file body 1 and a handle 2, wherein the file body 1 comprises a core rod 11, a metal pipe 12 and a working surface 13, and the multi-layer metal pipe 12 is sleeved outside the core rod 11 layer by layer from inside to outside to form a tight package. The multi-layer metal pipe 12 is stepped and retracted from the tail end of the file body 1 to the handle end, and the outer surface of the inner layer metal pipe which is not covered by the outer layer metal pipe is a working surface 13 of the file body 1.

As shown in fig. 2, 3 and 4, different engraved shapes 14 are processed on the working surface 13 by means of laser, grinding and chemical treatment to form a rough surface. The engraved shape 14 may be an independent shape such as a rectangle, a crescent, or the like, or may be a thread continuously extending along the surface of the file 1, or a polygonal line.

In this embodiment, the file body 1 and the handle 2 are integrated, that is, the file body 1 and the handle 2 are respectively processed on the same multi-layer base material.

The manufacturing process of the embodiment comprises the following steps:

s1 processing the metal tube 12; as shown in fig. 5, a plurality of metal pipes with different sizes and the same shape are processed at the central part of the metal bar;

s2, manufacturing a substrate 3 having a multilayer structure; the base material 3 comprises a core rod and a metal pipe, and the metal pipe is tightly wrapped outside the core rod;

s2.1, as shown in figure 6, a core rod is plugged into the metal pipe with the minimum size, and the section size of the core rod is slightly smaller than the inner diameter of the metal pipe;

s2.2, as shown in fig. 7, sequentially sleeving a plurality of layers of metal pipes outside the metal pipe in the step S2.1 according to the sequence of the inner diameters from small to large to prepare a plurality of layers of pipes; the outer diameter of the inner layer metal pipe is 0.005-0.5mm smaller than the inner diameter of the outer layer metal pipe adjacent to the inner layer metal pipe;

s2.3, integrally drawing and annealing the multilayer pipe for multiple times to enable the metal pipe to be tightly wrapped outside the core rod; after drawing, the metal pipe and the core rod at the innermost layer are tightly wrapped, and a stable connecting structure is formed between different layers; the annealing temperature is 600-900 ℃, and the preferred temperature is 700-800 ℃;

s2.4 as shown in figure 8, the multilayer pipe is subjected to cold drawing until the diameter of the pipe is slightly larger than or equal to the diameter of a handle required by the root canal file, and a base material 3 is formed; the cold drawing deformation is 20-50%, and the preferred deformation is 30-40%;

s3 cutting the base material with length larger than or equal to the root canal file finished product;

s4, dividing the base material 3 into a file body 1 and a handle 2, and performing material reduction processing by a laser, grinding or chemical treatment method; as shown in fig. 9, the metal pipe is removed from the file body 1 from the outside to the inside layer by layer in the tail end direction; as shown in fig. 10, the handle 2 is cut off to form a handle;

s5 as shown in FIGS. 2-4, processing the surface of the working surface 13 with a carved shape by laser, grinding or chemical treatment to increase the roughness of the working surface 13; also can cut an outward-expanding brush wire or skirt at one end of the working surface far away from the handle along the axial direction of the file body 1, so that the root canal file has the function of cleaning residues.

Specifically, the method comprises the following steps:

at S1, the hollow structure of the metal pipe may be processed by an electric discharge punch, a wire electric discharge machine, or an electric discharge forming machine. The metal tube and the core rod can be made of metal materials such as nickel-titanium alloy, stainless steel, cobalt-chromium alloy, copper and the like.

In step S4, the method of reducing the material of the file 1 includes: the removed part of the outer layer metal pipe of the file body 1 is more than the removed part of the adjacent inner layer metal pipe, the material reduction difference of the two adjacent layers of metal pipes is the axial length of the working surface on the inner layer metal pipe, and the like, so that the exposed working surface is distributed in a step shape, and the appearance of the file body 1 is in a conical shape.

When the material is reduced, the edge of the working surface is processed into a smooth cambered surface or a pattern with a tooth shape according to the function required.

In step S5, the brush filaments are outwardly-stretched when one end of the working surface is cut into a long and thin strip, and the brush filaments are outwardly-stretched when one end of the working surface is cut into a skirt having a certain width.

Example 2:

the difference between this embodiment and embodiment 1 is that the root canal file is not formed integrally, and the file body 1 is first machined by reducing the material and then the file body 1 is connected to the handle 2. The method specifically comprises the following steps:

s3', cutting the base material 3 equal to the file body 1;

s4', as shown in figure 11, the base material 3 is processed by reducing material through laser, grinding or chemical treatment, the metal pipe on the outer layer of the working surface is removed layer by layer on the base material 3, a stepped working surface 13 is formed, and the file 1 with a conical appearance is formed; additionally processing a handle 2;

s5', the file body 1 and the handle 2 are connected together in an interference fit or welding mode;

s6', processing a carved shape on the working surface 13 by a laser, grinding or chemical treatment method, and increasing the roughness of the working surface 13; and the externally-opened brush filaments can be cut along the axial direction of the file body 1, so that the root canal file has the function of cleaning residues.

In this embodiment, the file body 1 and the handle 2 are separately processed and then mounted, and the two can be made of the same material or different materials for reducing the cost.

It should be noted that the above-mentioned embodiments enable a person skilled in the art to more fully understand the invention, without restricting it in any way. Therefore, although the present invention has been described in detail with reference to the drawings and examples, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention.

Claims

1. A process for preparing multi-layer root canal file includes the following steps:

s4, performing material reducing processing on the file body of the base material to enable the removed part of the outer layer metal pipe to be more than the removed part of the adjacent inner layer, wherein the difference of the material reducing of the two adjacent layers of metal pipes is the axial length of the working surface on the inner layer metal pipe, and so on, the exposed working surface is distributed in a step shape, and the appearance of the file body is in a conical shape; the edge of the working surface is a smooth cambered surface or a pattern with a tooth shape;

2. The process of claim 1, wherein the multi-layer file is prepared by: the length of substrate equals the finished length of root canal file, divide into file body and handle two parts with the substrate, subtracts material processing to file body and handle.

3. The process of claim 1, wherein the multi-layer file is prepared by: the length of the base material is equal to that of the file body, the file body and the handle are respectively processed, and then the file body and the handle are connected together through an interference fit or welding method.

4. The process of claim 1, 2 or 3, wherein: in step S4, the edge of the working surface is a wavy line or a zigzag broken line.

5. The process of claim 1, 2 or 3, wherein: in the step S5, the engraved shape is a rectangle, a triangle, a polygon or an irregular shape.

6. The process of claim 1, 2 or 3, wherein: in step S5, the engraved shape is a thread or a broken line extending continuously along the surface of the file body.

7. A multi-layer root canal file made using the process of claim 1, wherein: the novel file comprises a file body and a handle which are connected with each other, wherein the file body comprises a core rod, a plurality of layers of metal pipes and a working surface, and the plurality of layers of metal pipes are sleeved outside the core rod layer by layer from inside to outside to form a tight package; the length of the outer layer metal pipe is shorter than that of the adjacent inner layer, and the difference of the lengths of the two adjacent layers of metal pipes is the axial length of the upper working surface of the inner layer metal pipe; the working surface is distributed in a step shape, and the appearance of the file body is conical; the edge of the working surface of the brush wire is a smooth cambered surface or a pattern with a tooth shape; the working surface is provided with a carved shape, or a slender strip is cut at the part of the working surface, which is far away from the handle, along the axial direction of the file body, so that brush filaments or skirt edges which are outwards opened are formed.

8. The multi-layer root canal file according to claim 7, wherein: the file body and the handle are integrally formed.

9. The multi-layer root canal file according to claim 7, wherein: the file body and the handle are different parts and are connected in an interference fit or welding mode.

10. The multi-layer root canal file according to claim 7, 8 or 9, wherein: the engraving shape is a rectangle, a triangle, a polygon or an irregular shape; the edge of the working surface is a smooth wavy line or a zigzag broken line; the engraving shape is a screw thread or a broken line which continuously extends along the surface of the file body.