The present invention relates to a milling blank for an abutment attachment, a method for producing an abutment attachment and a computer program product for a programmable milling device.
The document EP 2 343 025 A2 describes a milling blank for an abutment attachment having a central, straight screw channel for the insertion of a fixing screw and for securing the milled abutment attachment.
However, if an abutment attachment having a laterally offset or asymmetric adhesive base is produced from the milling blank, the central screw channel will be partly exposed at the side. As a result, the adhesive surface of the adhesive base is reduced, as is the stability of the abutment attachment.
The object on which the invention is based is to specify a milling blank with which it is possible to produce an abutment attachment with a laterally offset adhesive base which exhibits high stability and a large adhesive area.
This object is achieved by subjects having the features as claimed in the independent claims. Advantageous embodiments of the invention are the subjects of the figures, the description and the dependent claims.
According to a first aspect of the invention, the object is achieved by a milling blank for an abutment attachment which can be secured to a dental implant, comprising a securing section having a screw channel for a fixing screw for securing the milled abutment attachment to the dental implant; and a milling section having a feed channel angled with respect to the screw channel for feeding the fixing screw to the screw channel. The screw channel and the feed channel have a cylindrical outline, for example. The milling section has a larger diameter than the securing section, for example, and is used for milling out the abutment attachment.
The technical advantage which is achieved as a result, for example, is that following the production of an abutment attachment having a laterally offset or asymmetric adhesive base, the feed channel runs in the interior of the abutment attachment and the adhesive surface is increased. The milling blank with angled feed channel is used for further processing on milling centers in laboratories or practices, so that an individual abutment attachment can be created.
In an advantageous embodiment of the milling blank, the screw channel comprises a conical section for the insertion of a fixing screw with conical neck. The technical advantage that is achieved as a result, for example, is that a flush fixing screw with a conical neck can be used. Using such a fixing screw, a form-fitting connection is produced and the force exerted is distributed over a large area. Cavities in which bacteria can accumulate are minimized. As a result of the conical configuration, the entire transition from the implant to the abutment attachment is reinforced considerably as compared with a conventional screw with head and straight shank. The stability of the abutment attachment is increased by a quarter in this way.
In a further advantageous embodiment of the milling blank, the angle of the feed channel with respect to the screw channel corresponds to half the opening angle of the conical section. The technical advantage that is achieved as a result, for example, is that a smooth and seamless transition between feed channel and screw channel can be implemented.
In a further advantageous embodiment of the milling blank, the conical section has a height of 1 mm to 5 mm. The technical advantage that is achieved as a result is, for example, that the stability of the milled and inserted abutment attachment is improved.
In a further advantageous embodiment of the milling blank, the conical section is arranged in the securing section. The technical advantage that is achieved as a result is, for example, that a straight feed channel is formed within the milling section and the stability of the milling blank and of the abutment attachment milled therefrom is improved.
In a further advantageous embodiment of the milling blank, the conical section has a titanium nitride coating, a diamond coating or a carbon coating. The technical advantage that is achieved as a result is, for example, that the fixing screw can be screwed in smoothly with respect to the conical section.
In a further advantageous embodiment of the milling blank, the milling section is cylindrical. The technical advantage that is achieved as a result is, for example, that the milling section can be machined uniformly during milling.
In a further advantageous embodiment of the milling blank, the securing section is arranged on the axis of the cylindrical milling section. The technical advantage that is achieved as a result is, for example, that the milling blank can be inserted into a milling tool by the securing section.
In a further advantageous embodiment of the milling blank, the feed channel merges seamlessly into the screw channel. The technical advantage that is achieved as a result is, for example, that canting of the fixing screw during insertion is prevented.
In a further advantageous embodiment of the milling blank, an opening of the feed channel is located in the edge region of a surface of the milling section that is opposite the securing section. The technical advantage that is achieved as a result is, for example, that a high inclination of the feed channel is achieved.
In a further advantageous embodiment of the milling blank, the securing section widens toward the milling section. The technical advantage that is achieved as a result is, for example, that the securing section forms a stable base for the milling section.
In a further advantageous embodiment of the milling blank, the securing section comprises a hexagonal section for insertion into a hexagonal recess. The technical advantage that is achieved as a result is, for example, that the securing section has an interface to all leading implants.
In a further advantageous embodiment of the milling blank, the angle between the screw channel and the feed channel is in the range from 5° to 20°. The angle between the screw channel and the feed channel is preferably 11°. The technical advantage that is achieved as a result is, for example, that the feed channel is located in a particularly suitable angular range, in which both insertion of the fixing screw and the production of an abutment attachment with a lateral offset are made possible.
In a further advantageous embodiment of the milling blank, the feed channel is widened in the area of the connection to the screw channel. The technical advantage that is achieved as a result is, for example, that insertion of the fixing screw into the screw channel via the feed channel is made easier.
In a further advantageous embodiment of the milling blank, the milling blank comprises a central recess for the insertion of a turning tool on a surface of the milling section that is located opposite the securing section. The technical advantage that is achieved as a result is, for example, that the milling blank can be inserted into a turning tool in a straightforward way.
According to a second aspect of the invention, the object is achieved by a method for producing an abutment attachment comprising the step of milling a milling blank as claimed in the first aspect. The technical advantage that is achieved as a result is, for example, that the abutment attachment can be produced in a straightforward way.
In an advantageous embodiment of the method, the method comprises the step of processing a data set which defines a physical area around the feed channel within the milling blank in which no machining of the milling blank is carried out by the method. The technical advantage that is achieved as a result is, for example, that a channel wall thickness of the milled abutment attachment around the angled feed channel has a predefined minimum thickness.
According to a third aspect of the invention, the object is achieved by a computer program product which comprises a program which can be loaded directly into a memory of a programmable milling device, comprising programming means for milling a milling blank as claimed in the first aspect, wherein the computer program product further comprises a data set which defines a physical area around the angled feed channel within the milling blank in which no machining of the milling blank is carried out by the milling device or machining of the milling blank by the milling device is not done. The technical advantage that is likewise achieved as a result is, for example, that a channel wall thickness of the milled abutment attachment around the angled feed channel has a predefined minimum thickness.
Exemplary embodiments of the invention are illustrated in the drawings and will be described in more detail below.
The milling blank 100 can be produced, for example, from grade 5 titanium (Ti-6Al-4V), so that a high strength with good ductility with a simultaneously low density is provided. In particular, this material provides good milling characteristics. In general, however, other suitable materials can also be used.
The milling blank 100 comprises a prefabricated securing section 103, which is used to secure the milled abutment attachment to the dental implant and is not processed further for this purpose. This securing section 103 forms, for example, a prefabricated interface to all leading implants. For this purpose, the securing section 103 has, for example, a hexagonal section 117 for insertion into a hexagonal recess of the dental implant
Located in the securing section 103 is a screw channel 105, into which a fixing screw for securing the abutment attachment to the dental implant is introduced. The fixing screw exerts a force on the abutment attachment following tightening via the screw channel 105, so that said attachment is seated firmly and non-rotatably on the dental implant. The screw channel 105 has a conical section 113.
Within the milling section 109 there extends a feed channel 111, angled by the angle α with respect to the screw channel 105, for feeding the fixing screw to the screw channel 105. The opening 115 of the feed channel 111 is located on the top of the cylindrical milling section 109.
The angle of the feed channel 111 with respect to the screw channel 105 corresponds to half the opening angle of the conical section 113. As a result, in a subregion between the feed channel 111 and the conical section 113, it is possible to achieve a straight transition, so that an inserted fixing screw can slide into the screw channel 105 without hindrance. Otherwise, the transition between the feed channel 111 and the conical section 113 is rounded, so that the feed channel 111 merges seamlessly into the screw channel 105.
The feed channel 111 and the screw channel 105 are shaped in such a way that it is possible to use an inverse socket fixing screw (inverse socket), such as a screw with a hexagonal projection, for example, by means of which considerably lower force peaks are produced during the fixing.
The conical section 113 has a height from 1 mm to 5 mm, for example, and is formed completely within the securing section 103. In addition, in the region of the conical section, the milling blank 100 can be provided with a coating made of titanium nitride, diamond or carbon material, so that the fixing screw can be tightened with little resistance.
The securing section 103 merges continuously and without corners into the milling section 109, which is formed by a cylindrical milled body. For this purpose, the securing section 103 comprises a transition section 119, which merges continuously into the milling section 109. The contour of the transition section 119 has a concave, inwardly curved form. As a result, on the outer side of the milling blank 100, a transition that has no edges or corners can be achieved between the securing section 103 and the milling section 109, and the stability of the abutment attachment is improved. The individual part of the abutment attachment is produced from the milling blank 100 during the further processing on milling centers in laboratories or practices.
The angle between the screw channel 105 and the feed channel 111 advantageously lies in the range from 5° to 20°. In this range, both insertion of the fixing screw and the production of an abutment attachment having a lateral offset are possible in a technically particularly simple way.
For this purpose, it is possible to provide a computer program product which comprises a program which can be loaded directly into a memory of a programmable milling device, comprising programming means for milling a milling blank when the program is executed by the milling device.
All the features explained and shown in conjunction with individual embodiments of the invention can be provided in a different combination in the subject matter according to the invention, in order at the same time to implement the advantageous effects thereof.
The protective scope of the present invention is given by the claims and is not restricted by the features explained in the description or shown in the figures.
100 Milling blank
103 Securing section
105 Screw channel
107 Abutment attachment
109 Milling section
111 Feed channel
113 Conical section
115 Opening
117 Hexagonal section
119 Transition section
Number | Date | Country | Kind |
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10 2013 102 402.5 | Mar 2013 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2014/054686 | 3/11/2014 | WO | 00 |