METHOD FOR PRODUCING BLANKS FOR ENDODONTIC INSTRUMENTS, AND SUCH BLANKS

Abstract

A method for producing blanks for endodontic instruments (1), endodontic instruments (1), and a delivery device. The method comprises the steps of providing at least one rod (2) and machining the at least one rod (2) by a wire erosion such that an erosion pattern (4) is applied to the at least one rod (2). The material eroded away from the at least one rod (2) at least partially deposits as a layer on the at least one rod (2). The layer of the re-deposited material has a surface hardness which substantially corresponds to the hardness of the material of the at least one rod (2).

Claims

1-9. (canceled)

10. A method for producing blanks for endodontic instruments, comprising the steps of: I) providing at least one rod; ii) machining the at least one rod by wire erosion so that a first erosion pattern is applied to the at least one rod, wherein material eroded away from the at least one rod at least partially deposits again as a layer on the at least one rod, and the layer of the re-deposited material has a surface hardness which substantially corresponds to a hardness of the material of the at least one rod.

11. The method according to claim 10, wherein the at least one rod has a length in a range of 1 to 15 m.

12. The method according to claim 10, wherein the at least one rod has a length in a range of 2 to 10 m.

13. The method according to claim 10, wherein the at least one rod has a length in a range of 3 to 4 m.

14. The method according to claim 10, wherein the layer of the re-deposited material has a surface hardness which is substantially 0 to 15% harder than the hardness of the material of the at least one rod.

15. The method according to claim 14, wherein the layer of the re-deposited material has a surface hardness which is substantially 0 to 8% harder than the hardness of the material of the at least one rod.

16. The method according to claim 14, wherein the layer of the re-deposited material has a surface hardness which is substantially 0 to 5% harder than the hardness of the material of the at least one rod.

17. The method according to claim 10, wherein at least one further erosion pattern is applied to the at least one rod, and the at least one further erosion pattern is designed such that the at least one further erosion pattern generates a different effect than the first erosion pattern during intended use of the endodontic instrument.

18. The method according to claim 17, wherein the different effect is a different cutting effect.

19. The method according to claim 10, wherein several rods are eroded simultaneously with one another.

20. The method according to claim 10, which method, after step ii), comprises a secondary treatment of the at least one rod (2) by at least one of: electropolishing; chemical polishing; heat treatment for adjusting the elasticity; and application of a coating.

21. The method according to claim 20, wherein the applied coating comprises at least one of diamond-like carbon (DLC) or boron nitride.

22. The method according to claim 10, wherein the method comprises, after step ii), cutting the at least one rod into desired lengths.

23. A blank for an endodontic instrument, obtainable by the method according to any of claim 10.

24. An endodontic instrument which can be produced from the blank according to claim 23, wherein the endodontic instrument has at least one of an attachment device or a holding device.

25. The endodontic instrument according to claim 24, wherein the holding device is a handle.

26. A delivery device, which is designed such that several rods can be delivered simultaneously or in succession into an erosion device for carrying out the method according to claim 10.

Description

[0025] The invention is explained below with reference to one figure and on the basis of measurement results.

[0026] FIG. 1 shows a schematic view of an endodontic instrument in the root channel of a tooth.

[0027] FIG. 1 shows an endodontic instrument 1 during the treatment of a molar 11. Here, the endodontic instrument 1 is partially inserted into a root channel 12 of the tooth 11. By means of movements of rotation and translation, the root channel 12 is cleaned, i.e. the root removed from the root channel 12, and widened. The endodontic instrument 1 comprises a handle 3 and a body 2. The body 2 is produced from a nickel-titanium alloy and has at least one erosion pattern 4. The erosion pattern 4 was introduced in a wire erosion method. The erosion pattern 4 is formed here, inter alia, by the deposition of eroded material. The erosion pattern 4 has cutting edges, which perform a cutting function during the intended use.

[0028] The hardness of the instruments was defined by the nanoindentation method (maximum forces 10 mN and 30 mN). The remnant depth ratio (RDR) was determined for the evaluation, likewise h.sub.max, h.sub.ver and the elastic modulus. In workpieces according to the invention, no significant difference in hardness could be identified between areas treated by EDM and areas not treated by EDM. In the endodontic application, instruments according to the invention showed excellent and homogeneous properties of bending and elasticity, without any cracking of surface material, even under intensive and prolonged stress.