DE102014203449A1 - Dental instrument - Google Patents

Abstract

The invention relates to a dental instrument with a provided with cutting head 1, which is fixed to a shaft 2, characterized in that at least one support element 4 is arranged in cutting gaps 5 between adjacent blades 3.

Description

The invention relates to a dental instrument with a head provided with cutting, which is attached to a shaft.

Dental instruments of the type mentioned can be designed, for example, in the form of milling cutters or drills. A typical application are rose drills, which are used in particular to abrade carious dentin.

In the treatment of a patient, in particular during excavation in the context of a cavity preparation, it is necessary to avoid friction surfaces to prevent thermal damage. This is especially important when the dentist is working near the pulp.

Another aspect of such rotating instruments is that, depending on the design and operating conditions in the known from the prior art instruments to a variety of vibrations. The frequency of the vibrations is dependent on the number of cutting edges or grinding tips on the circumference, which engage respectively. At a speed of, for example, 2,500 min- ¹ , at which such instruments are commonly used, both the patient and the dentist may find these vibrations uncomfortable and annoying.

The vibrations are caused by a sequence of cutting interventions of the individual cutting edges and subsequent areas in which no cutting insert takes place.

The invention has for its object to provide a dental instrument of the type mentioned, which allows a simple design and simple, inexpensive to manufacture a good removal rate and a low-vibration or vibration-free use.

According to the invention the object is achieved by the combination of features of claim 1, the dependent claims show further advantageous embodiments of the invention.

According to the invention, at least one support element is arranged in each case in cutting gaps between adjacent cutting edges.

The vibrations in such dental instruments preferably occur in that the cutting edge is in contact with a solid material, for example healthy dentin. Sick dentin is relatively small and can be easily removed. For hard, healthy dentin, the cutting edge rests against the surface to be worked during the cutting process. Upon rotation of the instrument, the blade leaves this area, eliminating direct contact with the blade. In the following cutting gap, the dental instrument usually has a smaller diameter. As a result, the dental instrument would approach the surface to be machined and possibly touch it before the next cutting edge lifts the dental instrument slightly again and comes into contact with the surface to be machined. This oscillating motion, the frequency of which increases with increasing speed, generates the undesirable vibrations according to the prior art. Here, the construction of the invention provides a remedy by at least one support element is disposed between adjacent cutting in the cutting gap. This comes into contact with the surface to be processed, so that no relative movements between the head of the dental instrument and the surface to be processed occur. As a result, there is a vibration-free or low-vibration running of the dental instrument.

In a particularly favorable embodiment of the invention it is provided that the support element either has a same radius (relative to the radius of the head), as the associated cutting, or a slightly smaller radius. With a slightly smaller radius it is ensured that the respective cutting edge can penetrate into the material to be processed without the undesirable relative movement between the head and the surface to be machined, which, as in the prior art, would cause vibrations.

The support element is convex in a preferred embodiment of the invention, in particular knob-shaped. It can thus be designed as a part-spherical elevation, so that there is a good coefficient of friction. The shaping prevents the material removed from accumulating between the support elements and impairing their function.

It is particularly favorable if a plurality of support elements are arranged in the cutting gap. The plurality of support elements may be formed in a uniform pattern or in an irregular arrangement. It is also possible to provide different sized support elements, depending on the respective radius of the head, the number of cutting edges and / or the axial position of the support elements.

It proves to be particularly favorable when the plurality of support elements in the cutting gap an area of max. Occupy 50% of the cutting gap. This ensures that sufficient chip space is available to receive the removed material.

In a further particularly advantageous embodiment of the invention, it is provided that in the cutting direction in front of the cutting edge, a groove-like chip space extending along the cutting edge is formed. This serves to receive the removed material chips and to transport them along the groove-like chip space.

The cutting edges are preferably arranged substantially in the axial direction, relative to a rotation axis of the instrument. This also leads to a uniform cutting load and a low-vibration running.

The dental instrument according to the invention thus has large chip spaces, but prevents relative movement of the head in contact with the surface to be machined, whereby on the one hand a high removal rate is ensured and on the other a low-vibration run.

The dental instrument according to the invention may be formed with two, three, four, six or eight cutting edges. It is preferably designed in the form of a rose drill, but may also be cylindrical, in the form of a flame, in a pear shape or the like.

The intended according to the invention form of the head of the dental instrument is preferably prepared either by means of an ablative laser process or an additive process. In an ablative laser process, the entire dental instrument is made of a semifinished product, for example a cylindrical rod, by means of which, by means of the laser, which is preferably a short-pulsing or ultrashort-pulsed laser, material is vaporized and thus removed. Damage to the remaining base material does not take place, since no significant thermal impairments occur. However, it is also possible to prepare a base body of the dental instrument according to the invention by machining and to produce only the specific configuration of the head with the cutting edges, the chip spaces and the support elements by means of an ablating laser.

In an additive process, which is based on a layered component manufacturing, numerous metal alloys, plastics and ceramics can be processed directly from CAD data to complex, customer-specific components. Thus, geometrically defined solids can be produced from an informal starting material (for example powder), for example by the beam melting or sintering process due to high-energy beam sources (laser or electron beam) or by polymerization by means of a chemical binder. In this way, functionally usable tools and components can be produced in a short time.

The dental instrument according to the invention can be made of steel, hard metal, titanium, ceramic or plastic.

In the following the invention will be described by means of an embodiment in conjunction with the drawing. Showing:

1 a perspective view of an embodiment of the dental instrument according to the invention,

2 a side view of the in 1 shown dental instruments,

3 a side view, analog 2 rotated by 90 °, and

4 an end view of the dental instrument.

The dental instrument according to the invention comprises a shaft 2 , which is provided at its rear end with conventional clamping means (annular groove and flattening), as is known from the prior art. At the front end portion of the shaft is a head 1 arranged. This has a substantially spherical basic shape. At this are three cutting edges 3 formed, which (see in particular 2 and 3 ) substantially in the axial direction, with respect to a rotation axis 7 , extend. The cutting 3 have a larger radius than the spherical basic structure of the head 1 as in 4 is shown. With the reference number 8th is in 4 a resulting upon rotation of the dental instrument envelope represented by the cutting 3 is defined.

Between the cutting edges there is a cutting space 5 educated. In the cutting room 5 are knob-shaped support elements 4 arranged, which are supported against a surface to be machined, when the cutting 3 not in cutting engagement.

In the presentation of 4 a rotation takes place around the axis of rotation 7 in the counterclockwise direction. In the cutting direction in front of the cutting edges 3 are each groove-like chip spaces 6 intended.

The embodiment shown comprises three cutting edges 3 However, it is also possible to provide a smaller or larger number of cutting, for example, two, four, six or eight cutting.

The support elements 4 are essentially uniform on the surface of the head 1 or the cutting gaps 5 arranged so that it can always be supported. Overall, the support elements occupy less than 50% of the total volume or total area of the interdental space. There is thus a sufficient space in which chips can be introduced.

The nub structure formed by the support members may be either by removing material from the cutting gap, depending on the manufacturing process used 5 be produced by means of a laser ablating or by material addition by means of an additive method.

LIST OF REFERENCE NUMBERS

1

head

2

shaft

3

cutting edge

4

support member

5

Cut gap

6

chip space

7

axis of rotation

8th

envelope

Claims (10)

Dental instrument with a head provided with cutting edges ( 1 ), which on a shaft ( 2 ), characterized in that in cutting gaps ( 5 ) between adjacent cutting edges ( 3 ) in each case at least one support element ( 4 ) is arranged. Dental instrument according to claim 1, characterized in that the support element ( 4 ) has an equal or a smaller radius, relative to the radius of the head, as the associated cutting edges ( 3 ). Dental instrument according to claim 1 or 2, characterized in that the support element ( 4 ), convex, in particular knob-shaped. Dental instrument according to one of claims 1 to 3, characterized in that a plurality of support elements ( 4 ) in the cutting gap ( 5 ) are arranged. Dental instrument according to claim 4, characterized in that the plurality of support elements ( 4 ) in the cutting gap ( 5 ) an area of maximum 50% of the cutting gap ( 5 ). Dental instrument according to one of claims 1 to 5, characterized in that in the cutting direction in front of the cutting edge ( 3 ) along the cutting edge ( 3 ) extending groove-like chip space ( 6 ) is trained. Dental instrument according to one of claims 1 to 6, characterized in that the cutting edges ( 3 ) substantially in the axial direction, relative to a rotation axis ( 7 ) of the instrument are arranged. Dental instrument according to one of claims 1 to 7, characterized in that it is designed as a rose drill. Dental instrument according to one of claims 1 to 8, characterized in that this is produced by means of a removing laser process. Dental instrument according to one of claims 1 to 8, characterized in that this is produced by means of an additive process.

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