Dental bur and method of manufacturing the same

Abstract

This invention discloses a dental bur and its manufacturing method. Through a step-by-step multi-layer abrasive application and vacuum brazing technology, a durable and efficient diamond bur with multiple layers of abrasive grains of equal height but uniform exposure height is obtained. This effectively solves the problem of chip space, reduces the heat generated during use, and promotes healthy tooth growth.

Description

Technical Field

[0001] This invention relates to dental instruments, and more particularly to a dental bur and a method for manufacturing the same. Background Technology

[0002] Diamond abrasives were first used in rotary dental instruments as early as the 1930s. Currently, in the industry, dental diamond burs widely employ electroplating to bond diamond abrasive grains to the smooth cylindrical surface of the bur. Most burs currently used in dental clinics utilize electrolysis, where the diamond abrasive grains are attached to the bur substrate through a plating layer. This process has the following problems: the diamond abrasive grains are only mechanically embedded or inlaid in the plating layer without forming a strong chemical or metallurgical bond. Therefore, the holding power of the diamond abrasive grains is relatively weak, and the grains are prone to detachment, reducing processing capacity. To solve the diamond holding power issue, the mechanical embedding depth of the plating layer needs to be increased. However, deeper embedding reduces the exposed portion of the diamond abrasive grains, decreasing sharpness during processing and eliminating space for tooth grinding debris. This leads to debris buildup, which can easily adhere and clog the debris-holding space, reducing the bur's lifespan. Furthermore, the rapid heating of the bur during grinding can damage healthy teeth. Summary of the Invention

[0003] In view of the above-mentioned deficiencies of the prior art, the technical problem to be solved by the present invention is how to improve the holding force of diamond abrasive grains on dental burs while increasing the chip space.

[0004] To achieve the above objectives, the present invention first provides a dental bur, comprising a shank and a working part, the base material being metal; multiple pits are formed on the working part, the diameter of the pits being 3-4 times the diameter of the diamond abrasive grains, and the depth of the pits being 2 / 3 of the diameter of the diamond abrasive grains; the diamond abrasive grains are fixedly distributed on the working part by welding with copper-based, silver-based, or nickel-based brazing filler metal; the area covered by the diamond abrasive grains on the working part is more than 90%.

[0005] Furthermore, the surface abrasive density of the lower layer of diamond abrasive grains is above 40%, and the surface abrasive density of the upper layer of diamond abrasive grains is above 45%.

[0006] Furthermore, the exposed height of the upper layer of diamond abrasive grains is 2 / 3 of the diamond abrasive grain diameter, and the exposed height of the lower layer of diamond abrasive grains is 1 / 3 of the diamond abrasive grain diameter.

[0007] Furthermore, multiple chip-receiving micropits with different widths and heights are formed between the diamond abrasive grains.

[0008] The present invention also provides a method for manufacturing a dental bur, comprising the steps of:

[0009] (1) Prepare the blank of the cutting needle; form multiple pits on the working part of the cutting needle. The diameter of the pit is 3-4 times the diameter of the diamond abrasive grain, and the depth of the pit is 2 / 3 of the diameter of the diamond abrasive grain.

[0010] (2) Prepare a layer of metal composite material on the surface of the needle blank matrix as the first underlayer, wherein the metal composite material is copper-based or silver-based hard solder;

[0011] (3) Distribute diamond abrasive grains evenly on the first layer to form a diamond abrasive grain lower layer;

[0012] (4) Weld the blank of the bur with the lower layer of diamond abrasive grains, and use copper-based or silver-based brazing filler metal as the solder.

[0013] (5) Prepare another layer of metal composite material as the second bottom layer. The metal composite material is a nickel-based brazing filler metal.

[0014] (6) Distribute diamond abrasive grains evenly on the second bottom layer to form the upper layer of diamond abrasive grains;

[0015] (7) Weld the blank of the bur with two layers of diamond abrasive grains on the top and bottom, and use nickel-based brazing filler metal as the solder.

[0016] Furthermore, the diamond abrasive grains in the upper and lower layers are staggered.

[0017] Furthermore, the thickness of the first layer is less than or equal to 1 / 3 of the diamond abrasive grain diameter; the thickness of the second layer is 1 / 3 of the diamond abrasive grain diameter.

[0018] Furthermore, the surface abrasive density of the lower layer of diamond abrasive grains is above 40%, and the surface abrasive density of the upper layer of diamond abrasive grains is above 45%.

[0019] Furthermore, the exposed height of the upper layer of diamond abrasive grains is 2 / 3 of the diamond abrasive grain diameter, and the exposed height of the lower layer of diamond abrasive grains is 1 / 3 of the diamond abrasive grain diameter.

[0020] Existing traditional electroplating methods for producing diamond burs result in limited exposed abrasive grain height and chip space due to the lack of strong chemical or metallurgical bonding caused by embedding or inlaying. This leads to chip adhesion and blockage during grinding, reducing bur lifespan. This invention addresses this issue by employing a step-by-step, multi-layer abrasive application process using vacuum brazing to create durable, high-efficiency diamond burs with multiple layers of uniformly high-height abrasive grains. This effectively solves the chip space problem, reduces heat generation during use, and promotes healthy tooth growth.

[0021] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the needle of the present invention;

[0023] Figure 2 This is a schematic diagram of the preparation of the first substrate according to the present invention;

[0024] Figure 3 This is a schematic diagram of the uniformly distributed lower layer diamond abrasive grains of the present invention;

[0025] Figure 4 This is a schematic diagram after the first welding of the present invention;

[0026] Figure 5 This is a schematic diagram of the preparation of the second substrate according to the present invention;

[0027] Figure 6 This is a schematic diagram of the uniformly distributed upper layer of diamond abrasive grains of the present invention;

[0028] Figure 7 This is a schematic diagram of the upper layer after welding according to the present invention. Detailed Implementation

[0029] The following description, with reference to the accompanying drawings, illustrates several preferred embodiments of the present invention to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms, and the scope of protection of the present invention is not limited to the embodiments mentioned herein.

[0030] In one specific embodiment of the present invention, the bur 100 is a bur in which the micro-diamond abrasive grains, the binder, and the matrix blank are firmly chemically or metallurgically bonded by welding.

[0031] like Figure 1 As shown, the first step is to prepare the bur blank. The bur blank includes a shank 110 and a working part 120, and its material is generally stainless steel, tungsten steel, stainless iron, or other metals. The surface of the working part of the bur blank is treated by mechanical, chemical or electrochemical, laser, or other methods. This treatment forms pits 10 on the surface, and the size of these pits 10 determines the sharpness of the abrasive grains and the chip spacing. The diameter R of the pit 10 is 3-4 times the diameter of the diamond abrasive grain, and the depth D of the pit 10 is 2 / 3 of the diameter of the diamond abrasive grain.

[0032] like Figure 2As shown, a layer of metal composite material is prepared as the first underlayer 2 on the substrate 1 of the needle blank. The metal composite material of the first underlayer 2 is a copper-based or silver-based brazing filler metal. The specific preparation method of the first underlayer 2 is not limited to electroplating, air plating, welding, vacuum treatment, spraying, cladding, or sputtering. The thickness of the first underlayer 2 is less than or equal to 1 / 3 of the diamond abrasive grain size. The first underlayer 2 can form a strong chemical bond or metallurgical bond with the surface of the substrate blank.

[0033] like Figure 3 As shown, the lower layer of diamond abrasive grains 3 are evenly distributed on the first layer 2, and the surface abrasive density of the diamond abrasive grains is more than 40% of the surface area of ​​the first layer 2.

[0034] like Figure 4 As shown, a bur blank with a first diamond abrasive layer 3 is welded. Copper-based or silver-based brazing filler metal is used. Welding is performed under high vacuum (10⁻³), and an appropriate temperature (800-950℃) should be selected based on the brazing filler metal. The thickness of the weld layer 4 is 1 / 3 of the average diamond abrasive grain size, fixing the diamond abrasive grains to the substrate blank having the first bottom layer 2.

[0035] like Figure 5 As shown, a second layer of nickel-based metal composite material, 5, is prepared on the welding layer 4 in the same manner as the preparation of the first underlayer 2. The specific preparation method of the second underlayer 5 is not limited to electroplating, air plating, welding, vacuum treatment, spraying, cladding, or sputtering. The thickness of the second underlayer 5 is 1 / 3 of the diamond abrasive grain size. The first underlayer 2 can form a strong chemical bond or metallurgical bond with the surface of the substrate blank.

[0036] like Figure 6 As shown, the upper layer of diamond abrasive grains 6 are evenly distributed between the lower layer of diamond abrasive grains on the needle blank, with a surface abrasive density of 45% or more. Electrostatic abrasive adsorption can be used to adsorb the abrasive grains between the existing abrasive grains.

[0037] like Figure 7 As shown, a diamond abrasive grain-coated bur blank is welded to obtain weld layer 7. Nickel-based brazing filler metal is used. Welding is performed under high vacuum conditions (10⁻³), and an appropriate temperature (970-1050℃) should be selected based on the brazing filler metal. At this point, the thickness of weld layer 7 is 2 / 3 of the diamond abrasive grain diameter.

[0038] The lateral spacing between the upper layer diamond abrasive grains 6 is L, and the height spacing between the lower layer diamond abrasive grains 3 and the upper layer diamond abrasive grains 6 is H. Multiple chip-receiving micro-pits K of varying widths and heights are formed between L and H. Therefore, the chips generated during grinding are removed through these micro-pits, preventing clogging during grinding, reducing operating temperature, and maintaining excellent grinding performance over a long period. After the upper layer of abrasive grains falls off, new abrasive grains L1, H1, and K1, as well as new micro-pits, are generated. The upper layer of abrasive grains will break down during use, forming new cutting edges.

[0039] like Figure 7 As shown, the exposed height h2 of the lower layer diamond abrasive grains 3 is 1 / 3 of the diamond abrasive grain diameter, indicating that most of it is embedded in the weld layer. Therefore, it can suppress wear on the surface of the weld layer and achieve excellent grinding durability. The exposed height h1 of the upper layer diamond abrasive grains 6 is 2 / 3 of the diamond abrasive grain diameter, and the exposed height of the abrasive grains is consistent, thus achieving excellent grinding performance. Simultaneously, the lower layer abrasive grains protect the weld layer while also effectively protecting the upper layer abrasive grains, making them difficult to detach.

[0040] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A dental bur, characterized in that, It includes a shank and a working part, with the base material being metal. Multiple pits are formed on the working part, with the diameter of each pit being 3-4 times the diameter of the diamond abrasive grain and the depth being 2 / 3 of the diameter of the diamond abrasive grain. Diamond abrasive grains are fixedly distributed on the working part by welding with copper-based, silver-based, or nickel-based brazing filler metal. The diamond abrasive grains cover more than 90% of the working part. The diamond abrasive grains consist of two layers of different heights, staggered from each other, with the upper layer of diamond abrasive grains evenly distributed between the lower layer. The exposed height of the upper layer of diamond abrasive grains is 2 / 3 of the diameter of the diamond abrasive grain, and the exposed height of the lower layer is 1 / 3 of the diameter of the diamond abrasive grain.

2. The dental bur as described in claim 1, wherein, The surface abrasive density of the lower layer of diamond abrasive grains is above 40%, and the surface abrasive density of the upper layer of diamond abrasive grains is above 45%.

3. The dental bur as described in claim 2, wherein, Multiple chip-receiving micropits with different widths and heights are formed between diamond abrasive grains.

4. A method for manufacturing a dental bur, characterized in that, Including the following steps: (1) Prepare the blank of the cutting needle; form multiple pits on the working part of the cutting needle. The diameter of the pit is 3-4 times the particle size of the diamond abrasive, and the depth of the pit is 2 / 3 of the particle size of the diamond abrasive. (2) Prepare a layer of metal composite material on the surface of the needle blank matrix as the first underlayer, wherein the metal composite material is copper-based or silver-based brazing filler metal; (3) Distribute diamond abrasive grains evenly on the first layer to form a diamond abrasive grain lower layer; (4) Weld the blank of the bur with the lower layer of diamond abrasive grains, and use copper-based or silver-based brazing filler metal as the solder; (5) Prepare another layer of metal composite material as the second bottom layer. The metal composite material is a nickel-based brazing filler metal. (6) Distribute diamond abrasive grains evenly on the second bottom layer to form the upper layer of diamond abrasive grains; (7) Weld the needle blank with two layers of diamond abrasive grains, and use nickel-based brazing filler metal; finally, two layers of diamond abrasive grains are obtained, with the upper layer of diamond abrasive grains evenly distributed between the lower layer of diamond abrasive grains; the exposed height of the upper layer of diamond abrasive grains is 2 / 3 of the diamond abrasive grain diameter, and the exposed height of the lower layer of diamond abrasive grains is 1 / 3 of the diamond abrasive grain diameter.

5. The method for manufacturing a dental bur as described in claim 4, wherein, The thickness of the first layer is less than or equal to 1 / 3 of the diamond abrasive grain diameter; the thickness of the second layer is 1 / 3 of the diamond abrasive grain diameter.

6. The method for manufacturing a dental bur as described in claim 5, wherein, The surface abrasive density of the lower layer of diamond abrasive grains is above 40%, and the surface abrasive density of the upper layer of diamond abrasive grains is above 45%.

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