CA2217036A1

CA2217036A1 - Cover diaphragm

Info

Publication number: CA2217036A1
Application number: CA002217036A
Authority: CA
Inventors: Axel Kirsch
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-06-08
Filing date: 1996-04-03
Publication date: 1996-12-27
Also published as: KR100250116B1; DE19520867C2; WO1996041594A1; DE19520867A1; AU5269596A; BR9609157A; JPH11507281A; HUP9802830A2; KR19990022607A; EP0830115A1; AU700349B2; HUP9802830A3

Abstract

A cover diaphragm (18) of physically compatible or at least partially resorbable material for the temporary covering of a recess in the body's bone tissue filled with bone-forming material, especially granulated hydroxyl apatite, in which the side of the cover diaphragm (18) facing the soft tissue and/or the bone tissue has a retention reinforcing device (36, 38, 42, 44, 46) to improve the retention of the soft tissue or the collagen structure on the cover diaphragm (18).

Description

~ CA 02217036 1997-09-30 COVER DIAPHRAGM

The invention is directed to a cover diaphragm of physically compatible, potentially at least partially resorbable diaphragm material for temporarily covering a recess in the proper body bone tissue filled with an ossiferous material, particularly hydroxyl apatite granules, whereby that side of the cover diaphragm facing toward the soft tissue and/or that side of the cover diaphragm facing toward the bone tissue (each) comprises/comprise a retention promoting device for improving the retention of the soft tissue or, respectively, of the (respective) collagen 0 structure(s) at the cover diaphragm, and the retention promoting device(s) (respectively) comprises/comprise at least one mechanical retention aid.
In bone and parodontal surgery, for example in the reconstruction of bones in plastic surgery or in surgical operations of the jaw, it is standard to fill bone voids in the form of recesses or cavities in the proper body bone tissue with ossiferous material that is usually composed of a mixture of bone replacement material, such as hydroxyl apatite granules, and proper body bone particles or of only bone replacement material or proper body bone particles by themselves. In order to assure that the ossiferous material is osseously permeated essentially only proceeding from the bone side until it has been osseously substituted by remod~ling events but is not undesirably permeated by connective tissue Iying under the mucous membrane, the recess ensues [sic] with non-bone tissue up to now. Only when an entirely osseous permeation of the ossiferous material is assured, namely, can the bone void be essentially completely eliminated and the ossiferous material be reintegrated in the proper body bone after the osseous permeation. Only as a result thereof can it be simultaneously achieved in parodontal surgery that, on the one hand, the bone is regenerated given the presence of a single-walled or multi-walled bone void at the tooth and, on the other hand, the parodontal material 3 o arises by new formation of cement on the root surface and of soft 3s~1T~J~~ L p~z~

,~ CA 02217036 1997-09-30 parodontal materiai from the healthy parodontal material Iying under the void.
EP 0 475 477 discloses a cover diaphragm of the above-described species wherein the cover diaphragm is in fact essentially completely resorbable, but whereby there is the possibility that the resorption of the cover diaphragm ensues so rapidly that the healing of the bone void and of the lost parodontal tissue or, respectively, of the dental cement can, under unfavorable conditions, be disturbed by the inflammation process accompanying any and all resorption of tissue foreign to the body.
0 Similar cover diaphragms having similar problems observable under unfavorable conditions are disclosed by EP 0 082 621 and by WO
90/01955.
US 4,816,339 shows a cover diaphragm composed of a plurality of layers, whereby these layers are not composed of resorbable diaphragm material but of materials containing polytetrafluorethylene. The multi-layer structure thereby serves the purpose of optimizing the incorporation properties, whereby, however, the lack of resorption of the diaphragm material can lead to long-term problems.
German Published Application 43 02 708 discloses a cover diaphragm of the species, whereby it is largely assured that the osseous .permeation of the ossiferous material and, thus, the healing of the bone void can ensue essentially undisturbed by the inflammation process accompanying any and all resorption of tissue foreign to the body in that the diaphragm material can be resorbed faster from the side facing away from the proper body bone than from the side facing toward the proper body bone.
The document WO 95/09583 likewise discloses an implant, whereby particular emphasis is placed on resistance and good adhesion in the condition of having grown into the bone tissue. This is achieved by a perforated surface that, in combination with elevations at the edge of the holes, offers an especially high resistance to shearing forces betweén ~ ~'àil~UTE ~

.. ~ CA 02217036 1997-09-30 ' the implant and the new bone tissue. As emphasized on page 3, first paragraph of the publication under discussion here, thus, value has been mainly placed on good stability in the ingrown condition of the implant.
The cover diaphragm of the species has definitely proven itself.
However, it is turned out to be desirable to provide the soft or, respectively, connective tissue surrounding the bone void with the possibility of quickly growing to the cover diaphragm, so that a good connection between the soft tissue and the bone restored later is assured.
This particularly but not exclusively of significance when the cover 0 diaphragm is to remain in the body.
The invention is based on the object of improving the cover diaphragm of the species to the effect that a faultless, stabilizing connection--that avoids relative movements--of the soft tissue or, respectively, collagen structures surrounding the bone void, which, after bleeding into the bone void, fills this out from the osseously predetermined granulation tissue, and the cover diaphragm is assured.
This object is inventively achieved in that the mechanically acting retention aid(s) is/are at least partially fashioned for being positively embraced by soft tissue and/or collagen structure(s) at the moment the cover diaphragm is introduced.
It is also inventively provided that the mechanical retention aid(s) is/are at least partially fashioned by projections and/or depressions of the cover diaphragm of the cover means.
The invention also provides that the mechanical retention aid(s) is/are at least partially formed by surface irregularities of the cover diaphragm of the cover means.
The invention also provides that the mechanical retention aids are at least partially formed by a tissue-like and/or fabric-like structure of the surface of the cover diaphragm of the cover means facing toward the soft tissue or, respectively, the bone tissue.

~JBsTlTuTE PA~ iE

. . CA 02217036 1997-09-30 3 oL
The invention also provides that the retention supporting devices is/are [sic] at least partially formed by appro,c riate selection of the chemical composition and/or of the morphological structure of the material of the cover diaphragm in that region of the cover diaphragm facing 5 toward the soft tissue or, respectively, the bone tissue.
The invention is also characterized by at least two layers having different structure and/or composition, whereby that layer facing toward the soft tissue comprises/comprise [sic] the retention promoting device(s).

Su~ u~ A~ .

~ CA 02217036 1997-09-30 The invention is also characterized by at least two layers having different structure and/or composition, whereby that layer facing toward the soft tissue comprises/comprise [sic] the retention promoting device(s).
The invention is also characterized by open micropores provided in the layer facing toward the soft tissue and/or in the layer facing toward the bone tissue.
Finally, the invention is characterized by chemically and/or physically acting docking aids for the soft tissue or, respectively, the collagen structure(s) that are provided in that region facing toward the soft 0 tissue and/or that region facing toward the bone tissue.
The invention is based on the surprising perception that one succeeds in effectively promoting the adhesion of the connective tissue or, respectively, of the soft tissue or, respectively, of the collagen structures that spread into the bone void in that the surface of the cover diaphragm facing toward the soft tissue or, respectively, connective tissue or, respectively, the bone void is fashioned such that retention promoting devices are provided for improving the adhesion of the respective tissue or, respectively, of the respective collagen structures, as a result whereof a reliable, stabilizing connection with the cover diaphragm is assured.
These, for example, can be a matter of mechanically acting devices for the preferably positive embrace by soft tissue or, respectively, connective tissue or, respectively, collagen structures.
Additionally or instead, chemical, i.e. molecularly acting docking aids can also be provided, these being potentially formed by a corresponding, specific ''special layer" of the cover diaphragm that, for example, faces toward the connective tissue. As a result of such a multi-layer fashioning of the cover diaphragm, it is possible to optimize the layer facing toward the connective tissue or, respectively, the bone void such that an especially good joining with the tissue that grows on or, respectively, with the corresponding collagen structures is assured. The ~ CA 02217036 1997-09-30 base layer can be fashioned such that an especially good cell-occlusive and/or mechanically supporting effect derives.
What is thereby critical in any case is that is becomes possible for collagen structures from the connective tissue to grow in on the basis of a corresponding fashioning, for example structuring as well, of the surface facing toward the soft tissue or, respectively, the bone tissue.
Further features and advantages of the invention derive from the following description in which exemplary embodiments are described in detail with reference to the schematic drawing.
Thereby shown are:
Figure 1 a first exemplary embodiment of a cover diaphragm of the invention in section perpendicular to the membrane plane;
Figure 2 a further exemplary embodiment of a cover diaphragm of the invention, in a view corresponding to Figure 1; and Figure 3 a further exemplary embodiment of a cover diaphragm of the invention, in a view corresponding to Figure 2.
As Figure 1 shows, that surface a [sic] cover diaphragm 18 facing toward the connective tissue or, respectively, soft tissue Iying at the top in the drawing comprises projections 36 and depressions 38 that are respectively fashioned such that they can be positively embraced by collagen structure of the connective tissue growing in from above, as a result whereof the retention of the connective tissue to the cover diaphragm 18 is improved.
Given the modified exemplary embodiment in Figure 2, the cover diaphragm 18 is constructed of a base layer 40 that faces toward the bone and of a cover layer 42, whereby the latter comprises open micropores 44 that are likewise suitable for the grow-in of collagen structures.
Given the exemplary embodiment of Figure 3, the cover diaphragm 3 o 18 comprises a back layer 46 on that side of the base layer 40 facing away from the cover layer 42, i.e. facing toward the bone void, this back .~ CA 02217036 1997-09-30 layer 46 being likewise provided with open micropores 44 that are suitable for collagen structures to grow in proceeding from the bone void.
The layers 42 and 46 thereby preferably exhibit such a resorption genetics that a resorption time of approximately 6 to 12 weeks derives in parodontal surgery and a resorption time of about 6 to 9 months derives in osteosurgery.
Both individually as well as in arbitrary combinations, the features of the invention disclosed in the above specification, in the drawings as well as in the claims can be critical for realizing the various embodiments 0 of the invention.

Claims

1. Cover diaphragm of physically compatible, potentially at least partially resorbable diaphragm material for temporarily covering a recess in the proper body bone tissue filled with an ossiferous material, particularly hydroxyl apatite granules, whereby that side of the cover diaphragm facing (18) toward the soft tissue and/or that side of the cover diaphragm (18) facing toward the bone tissue (each) comprises/comprise a retention promoting device (36, 38, 42, 44, 46) for improving the retention of the soft tissue or, respectively, of the (respective) collagen structure(s) at the cover diaphragm (18) and the retention promoting device(s) (respectively) comprises/comprise at least one mechanical retention aid (36, 38), characterized in that the mechanically acting retention aid(s) (36, 38) is/are at least partially fashioned for being positively embraced by soft tissue and/or collagen structure(s).

2. Cover diaphragm according to claim 1, characterized in that the diaphragm material is at least partially resorbable.

3. Cover diaphragm according to one of the preceding claims, characterized in that the mechanical retention aid(s) is/are at least partially fashioned by projections (36) and/or depressions (38) of the cover diaphragm (18) of the cover means.

4. Cover diaphragm according to one of the preceding claims, characterized in that the mechanical retention aid(s) is/are at least partially formed by surface irregularities of the cover diaphragm (18) of the cover means.

5. Cover diaphragm according to one of the preceding claims, characterized in that the mechanical retention aids are at least partially formed by a tissue-like and/or fabric-like structure of the surface of the cover diaphragm (18) of the cover means facing toward the soft tissue or, respectively, the bone tissue.

6. Cover diaphragm according to one of the preceding claims, characterized in that the retention supporting devices is/are [sic] at least partially formed by appropriate selection of the chemical composition and/or of the morphological structure of the material of the cover diaphragm (18) in that region (42) of the cover diaphragm (18) facing toward the soft tissue or, respectively, the bone tissue.

7. Cover diaphragm according to one of the preceding claims, characterized by at least two layers (40, 42, 46) having different structure and/or composition, whereby that layer (42) facing toward the soft tissue and/or that layer (46) facing toward the bone tissue comprises/comprise the retention promoting device(s) (44).

8. Cover diaphragm according to claim 7, characterized by open micropores provided in the layer (42, 46) facing toward the soft tissue and/or facing toward the bone tissue.

9. Cover diaphragm according to one of the preceding claims, characterized by chemically and/or physically acting docking aids for the soft tissue or, respectively, the collagen structure(s) that are provided in that region facing toward the soft tissue and/or that region facing toward the bone tissue.