MILLING TOOL FOR SEATING A SCREW IN A DENTAL STRUCTURE

Abstract

The invention relates to a milling tool for seating a screw in a dental structure, the screw being provided to be joined to a dental implant, wherein the tool comprises a coupling region provided for coupling to a milling machine and a working region defined by a rod that on one end supports a head having a plurality of cutting blades radially distributed with respect to a longitudinal axis of the coupling region, wherein each cutting blade has a lower cutting surface. Said lower cutting surface has a region with a convex curvature which has a radius that varies between a maximum and a minimum value, the maximum value of the radius being equal to 0.1350*Dh, wherein Dh corresponds to the diameter of the effective area of the milling tool, and the minimum value of the radius complying with the formula:

[00001]$R_{\min }=125\frac{\sqrt{2}.Math.0.0012\mathrm{Dh}}{3.2}$

Claims

1. A milling tool (1) for seating a screw (3) in a dental structure, the screw (3) being provided to be joined to a dental implant, wherein the tool comprises a coupling region (10) provided for coupling to a milling machine and a working region (20) defined by a rod (201) that on one end supports a head having a plurality of cutting blades (202) radially distributed with respect to a longitudinal axis of the coupling region (10), the cutting blades (202) comprising a distal portion and a proximal portion in respect of the rod (201), wherein each cutting blade (202) has an upper cutting surface (A) arranged at the distal portion of the cutting blade (202), a lower cutting surface (C) arranged at the proximal portion of the cutting blade (202) and a lateral cutting surface (B) extending between the upper cutting surface (A) and the lower cutting surface (C), characterized in that the lower cutting surface (C) has a region with a convex curvature extending between the lateral cutting surface (B) and the rod (201), the convex curvature being defined by a radius that varies between a maximum and a minimum value, the maximum value of the radius being equal to 0.1350*Dh, wherein Dh corresponds to the diameter of the effective area of the milling tool (1), and the minimum value of the radius complying with the formula:

2. The milling tool (1) according to claim 1, characterized in that the minimum radius is less that 0.1350*Dh.

3. The milling tool (1) according to claim 1, characterized in that the working region (20) comprises between two and six cutting blades (202).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 is a schematic elevation view of the arrangement of a milling tool according to the present invention in a channel for the arrangement of a screw element for dental implants;

[0026] FIG. 2 is a schematic elevation view of the arrangement of a milling tool according to the present invention in a channel for the arrangement of a screw element for dental implants, with the channel having a frustoconical intermediate cross section;

[0027] FIG. 3 is an elevation view and plan view of the tool according to the invention;

[0028] FIG. 4 is an expanded elevation view of the working region of the milling tool;

[0029] FIG. 5 is an elevation view of a screw for dental implants; and

[0030] FIG. 6 is a schematic elevation view of the arrangement of the screw inside the channel.

DESCRIPTION OF A PREFERRED EMBODIMENT

[0031] In light of the aforementioned figures, and in accordance with the adopted numbering, one may observe therein an example of a preferred embodiment of the invention, which comprises the parts and elements indicated and described in detail below.

[0032] As can be seen, an embodiment of the milling tool, generally indicated with the reference (1), is provided for seating a screw (3) in a dental structure, which has a size comprised between 1.4 and 2.5 mm. In particular, the tool (1) essentially comprises a coupling region (10) provided for coupling to a milling machine and a working region (20) which is defined by a rod (201) which on one end supports a head that has a plurality of cutting blades (202) radially distributed with respect to a longitudinal axis of the coupling region, wherein each one of the cutting blades (202) has upper cutting surfaces (A), lateral cutting surfaces (B) and lower cutting surfaces (C), as indicated in FIGS. 1, 2 and 4.

[0033] In the embodiment shown, the working region (20) comprises four radially distributed cutting blades (202), as can be seen in FIG. 3.

[0034] In reference to the lower cutting surface (C), in a profile view, the same has a region with a convex curvature which has a radius (R) that varies between a maximum and a minimum value, the maximum value of the radius being equal to 0.1350*Dh, wherein Dh corresponds to the diameter of the effective area of the milling tool.

[0035] On the other hand, the minimum value in millimeters of the radius (also called minimum radius) must comply with the following formula:

[00003]$R_{\min }=125\frac{\sqrt{2}.Math.0.0012\mathrm{Dh}}{3.2}$

[0036] Based on the foregoing description, a table is provided with a ratio between the diameter of the effective area of the milling tool comprised between 1.4 and 2.5 mm and the maximum and minimum radius admissible for the milling machine described herein:

TABLE-US-00002 Dh (mm) Rmax (mm) Rmin (mm) 1.4 0.189 0.093 1.6 0.216 0.106 1.8 0.243 0.119 2 0.270 0.133 2.5 0.338 0.166

[0037] The details, shapes, dimensions and other complementary elements used to manufacture the tool of the invention may be suitably replaced with others that do not depart from the scope defined by the claims below.

REFERENCES

[0038] Dc: diameter of the screw head [0039] Df: diameter of the screw channel [0040] Dt: diameter of the rod of the milling machine [0041] Dh: diameter of the effective area of the milling machine [0042] 1: milling tool [0043] 10 coupling region [0044] 20 working region [0045] 201 rod [0046] 202 cutting blades [0047] R radius of the lower cutting surface [0048] M size [0049] 2 channel [0050] 3 screw [0051] A upper cutting surface [0052] B lateral cutting surface [0053] C lower cutting surface