Dental drill and method for producing same

Abstract

The invention relates to a method for producing a dental drill that has a shank (1) and a work section. The shank contains a centrally arranged, continuous first channel (3). The work section contains one or more continuous, spiral-shaped further channels (4a, 4b). The first channel and the further channels open into a common chamber (5) connecting the shank and the work section. The shank is sintered with the work section in order to form a one-piece, sintered component that encloses the chamber connecting the shank and the work section.

Claims

1. Dental drill with a shank (1) and a work section (2), wherein the shank has a centrally arranged, continuous first channel (3), the work section has more than one internal continuous, helically extending further channels (4a, 4b), a chamber (5) is provided between the shank and work section, the first channel and the further channels open into the chamber and the shank and the work section form a one-piece component which is connected by sintering and which completely encloses the chamber (5) connecting the shank (1) and the work section (2), wherein the transition region between the shank and the work section is free of additional connection materials, wherein the transition region between the shank and the work section has no visible seam locations or joint locations and wherein the chamber is disc-shaped; and the chamber (5) is in radial direction of the drill broader than the first continuous channel (3) in shank (1); and end regions of the further channels (4a, 4b) opening into chamber (5) are still helically twisted.

2. Dental drill with a shank (1) and a work section (2), wherein the shank has a centrally arranged, continuous first channel (3), the work section has more than one internal continuous, helically extending further channels (4a, 4b), a chamber (5) is provided between the shank and work section, the first channel and the further channels open into the chamber and the shank and the work section form a one-piece component which is connected by sintering and which completely encloses the chamber (5) connecting the shank (1) and the work section (2), wherein the transition region between the shank and the work section is free of additional connection materials, wherein the transition region between the shank and the work section has no visible seam locations or joint locations and wherein the chamber (5) is slot-shaped; and the chamber (5) is in radial direction of the drill broader than the first continuous channel (3) in shank (1); and end regions of the further channels (4a, 4b) opening into chamber (5) are still helically twisted.

3. Dental drill with a shank (1) and a work section (2), wherein the shank has a centrally arranged, continuous first channel (3), the work section has more than one internal continuous, helically extending further channels (4a, 4b), a chamber (5) is provided between the shank and work section, the first channel and the further channels open into the chamber and the shank and the work section form a one-piece component which is connected by sintering and which completely encloses the chamber (5) connecting the shank (1) and the work section (2), wherein the transition region between the shank and the work section is free of additional connection materials, wherein the transition region between the shank and the work section has no visible seam locations or joint locations and wherein the chamber (5) is polygonal; and the chamber (5) is in radial direction of the drill broader than the first continuous channel (3) in shank (1); and end regions of the further channels (4a, 4b) opening into chamber (5) are still helically twisted.

4. Dental drill with a shank (1) and a work section (2), wherein the shank has a centrally arranged, continuous first channel (3), the work section has more than one internal continuous, helically extending further channels (4a, 4b), a chamber (5) is provided between the shank and work section, the first channel and the further channels open into the chamber and the shank and the work section form a one-piece component which is connected by sintering and which completely encloses the chamber (5) connecting the shank (1) and the work section (2), wherein the transition region between the shank and the work section is free of additional connection materials, wherein the transition region between the shank and the work section has no visible seam locations or joint locations and wherein the chamber (5) is conical; and the chamber (5) is in radial direction of the drill broader than the first continuous channel (3) in shank (1); and end regions of the further channels (4a, 4b) opening into chamber (5) are still helically twisted.

5. Dental drill with a shank (1) and a work section (2), wherein the shank has a centrally arranged, continuous first channel (3), the work section has more than one internal continuous, helically extending further channels (4a, 4b), a chamber (5) is provided between the shank and work section, the first channel and the further channels open into the chamber and the shank and the work section form a one-piece component which is connected by sintering and which completely encloses the chamber (5) connecting the shank (1) and the work section (2), wherein the transition region between the shank and the work section is free of additional connection materials, wherein the transition region between the shank and the work section has no visible seam locations or joint locations and wherein the chamber (5) is cylindrical; and the chamber (5) is in radial direction of the drill broader than the first continuous channel (3) in shank (1); and end regions of the further channels (4a, 4b) opening into chamber (5) are still helically twisted.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantageous characteristics of the invention are evident from the exemplifying explanation thereof by way of the figures, in which:

(2) FIG. 1 shows a longitudinal sectional illustration of a dental drill according to a first embodiment of the invention,

(3) FIG. 2 shows a longitudinal sectional illustration of a dental drill according to a second embodiment of the invention,

(4) FIGS. 3A, 3B, 3C, and 3D show diagrams for explanation of a method of producing a dental drill according to the invention and

(5) FIGS. 4A and 4B show a longitudinal sectional illustration of a dental drill according to a third embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) Dental drills according to the invention have a shank and a work section, wherein the shank has a centrally arranged, continuous first channel, the work section has one or more continuous, helically extending further channels, the first channel and the further channels open into a common chamber connecting the shank and the work section and the shank and the work section are sintered together. A design of that kind of a dental drill creates the possibility of transporting, during working operation of the dental drill, a sufficient quantity of coolant, particularly cooling liquid, directly to the cutting region of the work section of the dental drill so that cooling, which is improved by comparison with known dental drills, of the cutting region and the currently treated tooth of the patient is achieved.

(7) FIG. 1 shows a diagram of a longitudinal sectional illustration of a dental drill according to a first embodiment of the invention. This dental drill has a cylindrically formed shank 1 and a similarly cylindrically formed work section 2. A continuous first channel 3 extending in axial direction is centrally provided in the shank 1. The diameter of the shank 1 is denoted by d1.

(8) Provided in the work section 2 of the dental drill are two continuous, helically extending further channels 4a and 4b which communicate with the cutting region 2b of the work section 2. The diameter of the work section 2 is denoted by d2 and corresponds with the diameter d1 of the shank 1.

(9) A chamber 5 is provided in the interior of the dental drill in the transition region from shank 1 to work section 2. In the case of the embodiment shown in FIG. 1 this chamber 5 is of disc-shaped construction. Not only the first channel 3, but also the two helical further channels 4a and 4b open into the chamber 5, which can alternatively also be constructed to be slot-shaped, cylindrical, polygonal or conical.

(10) In working operation of the dental drill, for example for the preparation of a jawbone for later reception of an implant or for removal of caries from a tooth of a patient a coolant, particularly a cooling liquid, is delivered under low pressure into the first channel 3 from the bottom in FIG. 1. The coolant runs through the rectilinearly formed first channel 3, fills the chamber 5 provided in the transition region from the shank 1 to the work section 2, penetrates from the chamber 5 into the helically extending further channels 4a and 4b, runs through these and is then delivered in the cutting region 2b of the work section 2. Consequently, not only the cutting region forming the work region of the dental drill, but also the currently treated tooth of the patient are directly cooled by the coolant issuing from the channels 4a and 4b.

(11) The shank 1 and the work section 2 of the dental drill can consist of the same material or of different materials. The shank 1 preferably consists of steel, ceramic, hard metal or plastic and the work section 2 of steel, ceramic or hard metal. The cutting region 2b of the work section 2 can consist of the same material as the remaining part of the work section 2 or also of another material.

(12) FIG. 2 shows a diagram of a longitudinal sectional illustration of a dental drill according to a second embodiment of the invention. This dental drill has a cylindrically formed shank 1 and a similarly cylindrically formed work section 2. A continuous first channel 3 extending in axial direction is centrally provided in the shank 1. The diameter of the shank 1 is denoted by d1.

(13) Provided in the work section 2 of the dental drill are two continuous, helically extending further channels 4a and 4b communicating with the cutting region 2b of the work section 2. The diameter of the work region 2 is denoted by 2 and corresponds with the diameter d1 of the shank 1.

(14) A chamber 5 is provided in the interior of the dental drill in the transition region from the shank 1 to the work section 2. In the case of the embodiment shown in FIG. 2 this chamber 5 is constructed to be conical, but can also have a different shape. Not only the first channel 3, but also the two helical further channels 4a and 4b open into the chamber 5. In the illustrated embodiment the chamber 5 is provided in the shank 1. Alternatively thereto it can also be provided in the work section 2. A further alternative consists in providing a part of the chamber in the shank 1 and the other part of the chamber in the work section 2.

(15) In working operation of the dental drill, for example for removal of caries from a tooth of a patient, a coolant, particularly a cooling liquid, is introduced under pressure into the first channel 3 from the bottom in FIG. 2. The coolant runs through the rectilinearly formed first channel 3, fills the chamber 5 provided between the shank 1 and the work section 2, penetrates from the chamber 5 into the helically extending further channels 4a and 4b, runs through these and is then issued in the cutting region 2b of the work section 2. Consequently, not only the cutting region, which forms the work region of the dental drill, but also the currently treated tooth of the patient are directly cooled by the coolant issuing from the channels 4a and 4b.

(16) The shank 1 and the work section 2 of the dental drill can consist of the same material or of different materials. Preferably, the shank 1 consists of steel, ceramic, hard metal or plastic and the work section 2 of steel, ceramic or hard metal. The cutting region 2b of the work section 2 can consist of the same material as the remaining part of the work section 2 or also of a different material.

(17) FIGS. 3A to 3D shows diagrams for explanation of a method of producing a dental drill according to the invention. In that case, production of the dental drill shown in FIG. 1 is explained on the basis of FIGS. 3A and 3B and production of the dental drill shown in FIG. 2 is explained on the basis of FIGS. 3C and 3D.

(18) For production of the dental drill shown in FIG. 1 initially a shank 1 and a work section 2 are produced independently of one another. The shank 1 is shown in FIG. 3B. The work section 2 is illustrated in FIG. 3A.

(19) For production of the shank 1, plastic material is extruded by a first extrusion tool in such a manner that a first body, which consists of plastic material, with a centrally arranged, continuous first channel issues from the first extrusion tool. The first body issued from the first extrusion tool is of cylindrical construction and has a diameter d1. The body issued from the first extrusion tool is cut to a predetermined length l1 and then dried so that its consistency solidifies.

(20) For production of the work section 2, plastic material is extruded by a second extrusion tool in such a manner that a second body, which consists of plastic material, with rectilinearly extending further channels issues from the second extrusion tool. The body issued from the second extrusion tool is similarly of cylindrical construction. It has a diameter d2 which corresponds with the diameter d1 of the shank. The second body issued from the second extrusion tool is cut to a predetermined second length l2. The cut-to-length second body is subjected to a uniform twisting of a rolling motion, the speed of which constantly changes over the entire length l2, by means of a friction surface arrangement while being supported over its entire length. Helically extending further channels 4a and 4b, as illustrated in FIG. 3A, are thereby formed from the initially rectilinearly extending further channels. The body produced in this manner is dried so that its consistency solidifies. The chamber 5, which in the illustrated embodiment is of rectangular form, is ground into the rear region of the dried body. The cutting region 2b is similarly formed in the front region of the dried body by means of a grinding process.

(21) Thereafter—as is illustrated between FIGS. 3A and 3B by the arrows x—the bodies solidified by drying are placed against one another in axial direction and heated. This heating is carried out in such a manner that the mutually adjoining surfaces of the heated bodies melt and that the mutually adjoining surfaces are sintered together in such a manner that after connection thereof no seam locations or joint locations are visible. The sintered-together bodies are subsequently dried again so that the consistency thereof further solidifies.

(22) A one-piece sintered component, which completely encloses the chamber 5 connecting the shank 1 and the work section 2, is formed by the afore-described sintering of the shank to the work section. Consequently, the transition region between the shank and the work section is free of additional connecting materials of any kind.

(23) For producing the dental drill shown in FIG. 2 initially a shank 1 and a work section 2 are produced independently of one another. The shank 1 is shown in FIG. 3D. The work section 2 is illustrated in FIG. 3C.

(24) For production of the shank 1, plastic material is extruded by a first extrusion tool in such a manner that a first body, which consists of plastic material, with a centrally arranged, continuous first channel 3 issues from the first extrusion tool. The first body issued from the first extrusion tool is of cylindrical construction and has a diameter d1. The body issued from the first extrusion tool is cut to a predetermined length l3 and then dried so that the consistency thereof solidifies. The chamber 5, which in the illustrated embodiment is of conical construction, is ground into the front region of the dried body.

(25) For production of the work section 2, plastic material is extruded by a second extrusion tool in such a manner that a second body, which consists of plastic material, with rectilinearly extending further channels issues from the second extrusion tool. The body issued from the second extrusion tool is similarly of cylindrical construction. It has a diameter d2, which corresponds with the diameter d1 of the shank. The second body issued from the second extrusion tool is cut to a predetermined second length l4. The cut-to-length second body is subjected to a uniform twisting of a rolling motion, the speed of which constantly changes over the entire length l4, by means of a friction surface arrangement while being supported over its entire length. Helically extending further channels 4a and 4b, as illustrated in FIG. 3C, are thereby formed from the initially rectilinearly extending further channels. The body produced in this manner is dried so that the consistency thereof solidifies. The cutting region 2b is formed in the front region of the dried body by means of a grinding process.

(26) Thereafter—as illustrated between the FIGS. 3D and 3C by the arrows x—the bodies solidified by drying are placed against one another in axial direction and heated. This heating is carried out in such a manner that the mutually adjoining surfaces of the heated bodies melt and that the mutually adjoining surfaces are sintered together in such a manner that after connection thereof no seam locations or joint locations are visible. The bodies sintered together are subsequently dried again so that the consistency thereof further solidifies.

(27) A one-piece sintered component, which completely encloses the chamber 5 connecting the shank 1 and the work section 2, is formed by the afore-described sintering of the shank to the work section. Consequently, the transition region between the shank and the work section is free of additional connecting materials of any kind.

(28) FIG. 4A shows a longitudinal sectional illustration of a dental drill according to a third embodiment of the invention. In this third embodiment the chamber 5 provided in the transition region from the shank 1 to the work section 2 is of slot-shaped construction. The width of the chamber 5 in the radial direction of the dental drill is matched to the radial external dimensions of the helically extending channels 4a and 4b so that the chamber 5 does not protrude in radial direction outwardly beyond the helically extending channels. This is also apparent from the illustration on the righthand side of FIG. 4B, wherein this illustration shows a cross-sectional illustration of the dental drill along the section line S shown by a dot-dashed line on the lefthand side of FIG. 4A.

(29) In the case of the afore-described embodiments the shank in each instance has a centrally arranged central channel. According to a modified form of embodiment a dental drill can also be constructed in such a manner that the helically extending channels provided in the work region extend as far as the shank and also run completely through the shank. In this case the feed of coolant is provided into the grip member, which is not illustrated in the figures, of the dental drill.

(30) A chamber can, by way of example, similarly be provided there, through which chamber the cooling liquid supplied from a cooling liquid source is conducted onward in the helically extending channels of the dental drill.

(31) The chamber 5 is in radial direction of the drill broader than the first continuous channel 3 in shank 1. Also end regions of the further channels 4a, 4b opening into chamber 5 are still helically twisted.

REFERENCE NUMERAL LIST

(32) 1 shank 2 work section 2b cutting region of the work section 3 first channel 4a, 4b further channels 5 chamber d1 diameter of the shank d2 diameter of the work section l1, l3 length of the shank l2, l4 length of the work section