DE102009028824A1 - Bone or bone substitute cylindrical block for use during oral surgery for structuring of jawbones and for attachment of tooth implants, has axial borehole and/or continuous borehole running perpendicular to axis - Google Patents

Abstract

The block (1) has an axial borehole and/or a continuous borehole running perpendicular to an axis. The block is made of bone material or bone substitute material. The block is prefabricated and corresponds a standard dimension from a set of standard dimensions. The set of standard dimensions covers a diameter range within an area between 5-8 mm and a length within 8-11 mm. A peripheral section with higher material density covers a peripheral angle range between 90 and 250 degrees. The block is tapered upwardly in a conical shape on one side or two sides.

Description

The present invention relates to a block of bone or bone substitute material, in particular for the construction of jawbone and for attaching dental implants, wherein the block is at least partially cylindrically shaped.

Corresponding blocks are already known from the prior art. In particular, such blocks of bone material or bone substitute material are used in oral surgery to build damaged or insufficiently developed jawbones, especially in connection with the attachment of dental implants. Dental implants are anchored directly in the jawbone and must, in order to obtain a sufficient load capacity, grow over a sufficiently large surface with the jawbone or grow into it.

However, due to periodontal disease, dental diseases and in connection with the removal of diseased and no longer repairable teeth can breakouts and damage to the jawbone arise that no longer allow a secure anchoring of the implant in the jawbone. Natural anatomical conditions also sometimes lead to inadequate bone material being available in certain regions of a jawbone in which anchoring of an implant would take place, which does not permit sufficiently large-area contact between the implant and sufficiently stable bone material surrounding the implant.

One way to build additional bone material in the prior art is to mill the damaged or too narrow bone area either centrally from above from one side with a cylindrical cutter. In this way, when machining from above (with a face milling cutter or drill), a cylindrical cavity is formed, while during machining from the side, a partially cylindrical (maximum semi-cylindrical) lateral cavity arises in the jawbone. With the help of a hollow core drill is then from another area of the body, for example from a rear, more massive area of the jawbone or z. B. drilled out of the hip of the patient a bone cylinder and removed, which coincides in radius with the radius of the part-cylindrical cutout. This cylinder is then inserted into the cylindrical or partially cylindrical cavity and fixed and can grow together in this way with the jawbone, so that finally in this area a reinforced, thicker jawbone is created, which allows anchoring of an implant.

Instead of own bone material of the respective patient, bone replacement materials may also be used for this purpose, in particular hydroxyapatite, which is also a natural bone material, or tricalcium phosphate ceramics. Similarly, denatured animal bones or donor bone can be used.

It is also known to mix bone meal or bone substitute materials with a suitable binder material to a pasty mass and thus fill cavities, especially a milled part of the jaw bone and build on the original jaw bone out addition and then provisionally fix this material to the natural bone in to grow the structures formed by the replacement material.

When using cylindrical blocks, it is very important for a close-fitting and close contact of the cylinder surface with the corresponding cavity surface in the jawbone, so that both parts grow together well. Any intermediate layers or cells of other material, such. As gums, could prevent ingrowth or growth of the cylindrical block. It must therefore be ensured that the inserted into the cylindrical or partially cylindrical cavity block of bone or bone substitute material has a tight and close contact with the jawbone, that this contact permanently, d. H. at least for several weeks, is ensured.

For this purpose, the cylindrical blocks are often fastened with fixing screws directly to the jawbone. For this purpose, a corresponding hole is made at lateral attachment through the block and the cavity wall of the jawbone and then the block is fixed with a pin extending through this hole or a corresponding screw. In a central top-mounted cylinder, in which often two opposite side wall portions of the otherwise cylindrical cavity may be missing due to a too narrow jaw bone, attachment by a central axial bore and at the bottom of the cylindrical recess. Establishing a corresponding bore and securing the blocks in the patient's mouth during provisional fixation of the block in the patient's mouth is a relatively cumbersome, tedious and difficult process with a corresponding burden on the patient and the risk of failure and / or injury when For example, the block used tilted when attaching a drill from his seat or slides. Also the drill for Making the mounting hole must be recognized in the patient's mouth in the correct orientation and guided safely.

Compared to this prior art, the present invention seeks to provide a block of bone or bone substitute material and corresponding methods for producing and processing of such blocks, which allow a simplified and less stressful for the patient attachment and at the same time a safe and accurate and ensure a sufficiently tight fit in a milled, at least partially cylindrical cavity of the jawbone.

This object is achieved in that the block is prefabricated and corresponds to a standard dimension of a set of standard dimensions comprising several size steps. The prefabrication of corresponding blocks of bone or bone substitute material avoids removal of a bone cylinder from the body of the patient and thus reduces its burden. Furthermore, this ensures a very precise shaping of the bone cylinders, since the blocks either consist of an artificial bone substitute material or of denatured animal bones or donor bone, which are simple and easily accessible outside the patient and before insertion.

In order to meet the individual requirements, d. H. In order to provide appropriate cylinders for smaller and larger cavities, which take into account the respective anatomical conditions, it is also provided that the prefabricated blocks together form a set of different dimensions, but which are standardized and correspond, for example, with respect to their diameter exactly the outer diameters of milling cutters with which corresponding, at least partially cylindrical cavities are produced on the jawbone. Analogous to the cutters which have become established in this field and are available on the market, the set of different blocks should cover a diameter range within the range of 4 to 9 mm, in particular within a range of 5 to 8 mm and a length range within the range Range of 4 to 12 mm, in particular 8 to 11 mm, wherein the diameter dimensions are stepped and gradations in the range of 0.3 to 0.6 mm, preferably of for example 0.5 mm, and the length dimensions of a gradation of at least 1 to 2 mm should have. Of course, the gradation could also each amount to a quadruple of the aforementioned dimensions. The set of standard diameters should include at least three values from the group of values that are 5.5; 6; 6.5; 7; 7.5 and 8 mm. With regard to the standard lengths, a corresponding set of measures should cover at least three values from the group consisting of the length values 5, 6, 7, 8, 9, 10, 11 and 12 mm.

In view of the specific application, it is understood that such blocks should be sterilized and packaged sterile. In each case, a set of blocks with different dimensions may be provided in a common packaging unit, wherein, of course, each block is packaged sterile for itself.

In order to facilitate and accelerate the mounting and fastening, it is further provided that each block has either an axial and, alternatively, or in addition, a through bore running perpendicular to the axis of the block. If such a bore is already present in the prefabricated block, it is not necessary to make it in the mouth of the patient with inserted and provisionally fixed block. Rather, this prefabricated bore can serve as a guide bore to additionally drill only the respective underlying jaw bone to anchor a fixing screw therein, which then holds the block of bone or bone substitute material securely to the jawbone. In such a process slipping of the drill or tilting and slipping of the block is practically excluded because the existing hole only serves as a guide, while the block must be held only briefly in the at least partially cylindrical recess. This process can take place comparatively quickly and with much less risk, which puts less strain on the patient

A particular advantage of the prefabrication consists in the fact that the block then does not have to be completely cylindrical, but for example can also be flattened on one side with a larger radius of curvature, so that there is a cylindrical section on one side, the milled into a milled, partially cylindrical Recess is used, on the opposite side, however, a slight projection is given if the block is flattened accordingly. The same applies to central cylindrical recesses whose diameter exceeds the width of the jawbone, at least in the upper region. Such blocks can be flattened on both, the jawbone protruding sides on both sides to at least approximately adapt to the natural anatomical conditions, even if a certain supernatant against the patient's own jaw bone may still be desirable to generate sufficient bone material for the fixation of the implant This better anatomical adaptation, which is not a problem in an extracorporeal prefabrication, prevents stress and Irritation of the gums, which is over the block used and in turn must grow and heal. The prefabricated bore and / or the flattening and the remaining cylindrical wall sections of the block also provide the exact orientation when inserting the block.

Also, the upper and lower outer edges of the otherwise cylindrical block may be chamfered, chamfered or smoothed to minimize stress and irritation thereof, particularly on the gum-contacting side.

Furthermore, an embodiment of the present invention is preferred in which the block has regions of different material density over its cross section. Also, natural jawbone consists of different dense material, namely the outer, denser cortical layer and the more or less porous and in the structure spongy cancellous bone. These differently dense areas can be produced directly, in particular in the case of bone substitute material, or by removing the blocks from marginal areas of the bone from denatured or donor bones in such a way that the cortex occupies one side of the cylindrical or partially cylindrical block, in particular the outer side after removal.

The dental and maxillofacial surgeon then only needs to produce the corresponding part-cylindrical cavity with a (standardized) milling tool and then takes out a suitable bone block from a set of prefabricated bone blocks, inserts it and fixes it to the jawbone of the patient with the aid of the already prefabricated bore. Due to the significantly lower load and the shortening of the surgical procedure, this also accelerates healing in the area of surgical wounds. For attachment to the jawbone are transverse to or along the axis extending bores, the longitudinal bore can also be prepared in addition for the introduction of an implant or a lag screw for fixing an implant.

Bone blocks with a (buccal and / or lingual) flattened cross-section have u. a. also the advantage that in their use each slightly larger part-cylindrical cavities can be milled into the bone, which provide a larger area for growing and fixing, without therefore the block inserted into the cavity must be correspondingly large and expansive, since he on the or projecting beyond the jawbone side (s) significantly flattened and thus may be less bulky.

The production of corresponding blocks of bone and / or bone substitute material can be done very efficiently with the help of appropriate machinery and equipment on an industrial scale medical scale, so that the cost of appropriate operations and replacement materials are significantly reduced.

Further advantages, features and possible applications of the present invention will become apparent from the following description of a preferred embodiment and the associated figures. Show it:

1 Isometric views of two standardized cylinders of bone material with prefabricated holes,

2 a cross section through a jawbone with an inserted and provisionally fixed bone cylinder,

3 two sets of cylinders of different diameter and cross section, in one case the cross section being homogeneous and in the other case the cross section having regions of different density,

4 a side view and a plan view of a block in a part-cylindrical shape with a flattened and conically tapered outer side, and

5 a side view and a plan view of a block in a part-cylindrical shape with opposite, flattened on both sides and conically tapering outer sides.

One recognizes in 1 two schematically illustrated cylindrical blocks 1 which may be made of bone material or bone substitute material, one of which is a vertical bore 2 and the other a horizontal hole 3 having. The cylinders could also have both a horizontal and a vertical bore 2 . 3 have, wherein the vertical bore 2 is also prepared for the insertion of the lag screw of an implant (not shown here), while the horizontal bore 3 only the temporary attachment of the block 1 on a jawbone 4 serves. Alternatively, however, both the horizontal and the vertical bore could be omitted, in the event of a lack of horizontal bore, for example, a temporary attachment by means of a clamp or the like can take place.

For example, after a cylindrical block 1 with a horizontal hole in a partially cylindrical, milled recess laterally or centrally in a jawbone 4 has been used, as in 2 shown, serves the horizontal (or vertical) bore as a guide hole, behind it still a hole with possibly smaller diameter in the jawbone 4 and then insert a screw (not shown) through the hole 3 to pass and into the jawbone 4 screwed. The horizontal hole 3 in the block 1 may also have a suitable recess for receiving a corresponding, special screw head, so that it does not protrude over the surface of the cylinder.

Because the screw after ingrowth of the block 1 in the jawbone 4 can also be removed again, regardless of the horizontal hole 3 in addition, the vertical bore 2 be provided for receiving an implant and for anchoring a lag screw.

An inventive set of blocks consists for. B. of three cylinders of different diameters, wherein the diameter z. B. 5.5; 6.5 and 7.5 mm could be like this in 3 is shown. 3 shows two corresponding sets of blocks 1 in cross section. At the right in 3b The set shown is the cross-section of the blocks 1 homogeneous, whereas the left in 3a illustrated set of blocks 1 Has areas of different density. It is at the after insertion in the jawbone outer side of the cylinder a harder area 5 greater density, which corresponds to the cortex of the bone, while the remaining area 6 of cancellous bone. The harder and denser area 5 is approximately crescent-shaped in cross-section and extends in the circumferential direction over about 200 to 240 ° and its radial thickness is predominantly, except for the tapered end portions, in about 20% of the diameter of the block.

2 shows a jawbone with an inserted cylindrical block 1 in cross section, being clear that the block 1 on the outside clearly on the contour of the remaining jaw bone 4 protrudes to provide sufficient space for attachment of an implant can.

However, this does not necessarily require the full cylinder volume, so according to 4 a further preferred embodiment of the invention is shown, in which the prefabricated block 1' flattened on one side and in addition tapered conically upwards. Even such a block may still protrude beyond the original or natural contour of the jawbone, but is more closely approximated to the rest of the structure, and in this way also causes less irritation to the gums during the healing process.

In such an alternative embodiment, as for example in 4a is shown in plan view, a corresponding bone cylinder is greatly flattened on one side and there has a much larger radius of curvature, but is rounded in the smaller radius of curvature, which also corresponds to the radius of the other embodiments and the corresponding, milled cavities on the jawbone. In this case is an area 5 Higher density along the flattened outside provided, up to a third of the thickness of the flattened block 1' can make out. In addition, such a block, as shown in 4a shown to be tapered conically to an even better fit to the cross section of a normal, healthy jawbone 4 make that through such a block 1 replaced or partially rebuilt.

Alternatively shows 5 a two-sided conical and flattened on both sides block for a central arrangement on a jawbone 4 ,

Even with these, only partially cylindrical formed with a corresponding cylinder radius blocks 1' respectively. 1'' can of course transverse and longitudinal bores 3 respectively. 2 be provided, as with respect to a transverse bore 3 in 4b and a longitudinal bore 2 in 5 is indicated.

For purposes of the original disclosure, it is to be understood that all such features as will become apparent to those skilled in the art from the present description, drawings and dependent claims, even though they have been specifically described only in connection with certain further features, both individually and can be combined in any combination with other features or feature groups disclosed herein, unless this has been expressly excluded or technical conditions make such combinations impossible or pointless. On the comprehensive, explicit representation of all conceivable combinations of features and the emphasis on the independence of the individual characteristics of each other is omitted here only for the sake of brevity and readability of the description.

Claims (12)

Block of bone or bone substitute material, in particular for the construction of jawbones and for attaching dental implants, wherein the block is at least partially cylindrically shaped, characterized in that the block is prefabricated and corresponds to a standard size of a set of standard sizes comprising several size steps , Block according to claim 1, characterized in that the set of standard dimensions covers a diameter range within the range of 4 to 9 mm, in particular 5 to 8 mm and a length range within the range of 4 to 12 mm, in particular 8 to 11 mm, wherein the Diameter measures a gradation of at least 0.3 to 0.6 mm, preferably of 0.5 mm, and the length dimensions of a gradation of at least 1 to 2 mm. A block according to claim 1 or 2, characterized in that the set of standard diameters comprises at least three values from the group of values 5.5; 6; 6.5; 7; 7.5 and 8 mm. Block according to one of claims 1 to 3, characterized in that the set of standard lengths comprises at least three values from the group 5, 6, 7, 8, 9, 10, 11 and 12 mm. Block according to one of claims 1 to 4, characterized in that it is sterilized and sterile packed. Block according to claim 5, characterized in that it is part of a set of blocks of different dimensions in a packaging unit. Block according to one of claims 1 to 6, characterized in that the block over its cross section has regions with different material density. A block according to claim 7, characterized in that the block has a higher density over at least a part of its circumference and in a layer thickness which corresponds to more than 10% and less than 40% of the diameter, than in the remaining cross-section. Block according to claim 8, characterized in that the peripheral portion or the peripheral portions with higher material density comprises a circumferential angle range between at least 90 ° and at most 250 °. Block according to one of claims 1 to 9, characterized in that the block has at least one axial and / or at least one perpendicular to the axis extending through bore. Block according to one of claims 1 to 11, characterized in that the block is flattened on one side or on both sides. Block according to one of claims 1 to 11, characterized in that the block is formed on one or both sides tapering conically upwards.

Images