CA2235705A1

CA2235705A1 - Integral guided tissue regeneration barrier for root-form dental implant

Info

Publication number: CA2235705A1
Application number: CA 2235705
Authority: CA
Inventors: Douglas Alan Schappert
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-04-23
Filing date: 1998-04-23
Publication date: 1999-10-23

Description

INTEGRAL GUIDED TISSUE REGENERATION BARRIER
FOR ROOT-FORM DENTAL IMPLANTS
The present invention relates generally to the field of dental implants.
s BACKGROUND OF THE INVENTION
Predictably useful dental implants had their beginnings in Sweden in the 1960's in work done by Per-Ingmar Branemark, who discovered that lab animals' bone cells would deposit mineralized bone directly on implanted titanium objects, thereby solidly attaching them to the surrounding bone. He is credited with coining io the term osseointegration, which is now in common use, to identify this process.
Since his discovery, thousands of titanium implants of mostly screw-type design have been inserted in people's toothless spaces to anchor prosthetic teeth. This implantation has been done almost exclusively by elevating the soft tissue, drilling a hole in bone, placing the implant in the hole, stitching the soft tissue back over the is implant, waiting a period of months, re-opening the soft tissue, uncovering the implant and attaching a stud to project through the gum. If bone augmentation has been necessary, yet more operatians have been required.
If one counts the extraction surgery that leads to most toothless spaces, patients progressing from having teeth to having a toothless space, then getting an 2o implant and fastening on a prosthetic tooth, must submit to at least three surgeries.
The total rises to five if bone augmentation is required and done as a separate procedure. The number of surgeries would be reduced to one if an implant inserted on tooth removal would osseointegrate. If this could be done, patients would expE~rience fewer painful, expensive and time-consuming surgeries and avoid bone loss in extraction sites, which is associated with problems of appearance, comfort and insufficient bone volume for eventual implants. Their periods of wearing s temporary prosthetic replacement teeth or doing without teeth would be shorter.
The unpredictability of success with currently available technology has meant that only a tiny proportion of implants have been placed in tooth sockets immediately after teeth have been removed. Causes of failure have been presence of bacteria in the sockets, implant movement in the tooth socket due to the implant io being inadequately fixed in place, and soft tissue layers being deposited against titanium) preventing osseointegration. One can reduce or eliminate bacteria from extr<~ction sockets with surgical instruments, sterile technique and antibiotics. Soft tissue deposition and implant movement can be eliminated by the present invention:
a guided-tissue-regeneration barrier integrated with root-form dental implants.
is Placing a barrier to prevent migration of selected cell types into selected areas to control tissue formation during healing is termed guided tissue regE~neration (GTR). A GTR barrier fixed around an implant could prevent migration of fibroblasts and epithelial cells into the healing socket, preventing fibrous tissue or epithelium from being created there, and allowing slower-migrating bone cells 20 (osteoblasts) to populate the socket and deposit bone throughout, including directly on the surface of the implant, osseointegrating it into the jaw to be an anchor for a prosthetic tooth.

A barrier securely attached to an implant could increase its stability.
The barrier would need to be malleable in order to be closely adapted to the surface of the bone of the alveolar crest surrounding the extraction site. It would have to retain the form into which it was shaped and allow circulation to be established s through it, in order to prevent it from becoming exposed. It would need to be easy for a surgeon to cut it to fit around adjoining teeth and within the limits of the surgical site. It could not cause an inflammatory response, so that the overlying mucosa sutured tightly over it would remain firm and capable of preventing it from moving. Its rigid connection to the implant member of the implant-barrier combination would help io the implant resist displacement forces applied to it.
Ideally, it should be possible to insert implants in tooth sockets immediately after removal of teeth with predictably successful osseointegration, by performing the two functions of excluding unwanted cells from the extraction socket and increasing the stability of the implant.
is An integrated guided-tissue-regeneration barrier for root-form dental implants could be made either from a material which would be resorbed after it had served its purpose, or of a material that would remain permanently in place around the implant. There is, however, no non-resorbable barrier material that is conventionally being left in place after periodontal or implant-related guided tissue zo regeneration. Expanded polytetrafluoroethylene, the most common GTR barrier in use over the last 20 years, can be left in place for only a few weeks because of its disadvantages. In common with other textiles, it cannot be formed into a 3-dimE~nsional shape that it will retain, so surgeons cannot place it precisely where they want it. It penetrates the overlying gum in a high proportion of cases because of its tendency to revert to its original flat shape and because blood vessels cannot penetrate it. It will not support itself over a void and must therefore be supported by another material placed on the bone. (It is useful as a GTR barrier despite its s disadvantages because it has pores small enough to prevent cellular migration and bec<~use it does not provoke inflammation).
Titanium foil and mesh have been tried as alternative barriers. Both have successfully permitted bone growth) but foil shares expanded polytetrafluoroethylene's propensity to penetrate the overlying gum, and must be io removed once the new bone has formed. Mesh, however, has none of the above-mentioned disadvantages. It can be formed into complex three-dimensional shapes, cut i:o shape, and is rigid enough to contribute to the stability of an implant inserted through it. It looks to be a useful material for ensuring that osteoblasts can migrate to where they are wanted without having to win a race with faster-moving fibroblasts is and epithelial cells. Titanium mesh is being embedded and left permanently in place in people's jaws (and other parts of their bodies) during other types of surgery., Like titanium implants, it does not provoke an inflammatory response in these situations and is well-tolerated by the surrounding tissue. Dr John Gay and his associates in Toronto have used titanium mesh barriers to promote bony infill with GTR. When 2o doing re-entry surgery to remove the barriers, they have noted absence of inflammation, intimate tissue adaptation to the mesh, and a considerable degree of difficulty in removing the mesh. They question whether it is really necessary to remove the titanium mesh barrier material, which they and other surgeons do insert permanently when doing orthognathic surgery, for example.
Titanium mesh, either on its own or bonded to a rib reinforcement system stamped from light gauge (in the neighbourhood of 50 micron thickness) s sheet titanium could be used to form a permanent integrated guided tissue regE:neration barrier for root-form dental implants.
If the barrier were to be resorbable, it could be made of a rib reinforcement system stamped from light gauge sheet titanium bonded to a resorbable membrane such as a bioabsorbable collagen membrane made of type I
io bovine tendon collagen. The titanium reinforcement system would permit the barrier to be formed to the shape of the bone surrounding the implant, to retain the shape once formed and to be light enough to allow a surgeon to cut the barrier to fit the surctical site. As well, the reinforcement system would allow the barrier to fit tightly and securely about the implant, so as to provide an effective barrier to the passage of is unwanted cells right up to the implant and contribute to the positional stability of the impllant. Only the barrier membrane would be resorbable: the rib reinforcement system would remain permanently.
Without a titanium reinforcement system, lateral movement of an implant within a resorbable barrier would deform the barrier material. The resorbable 2o material by itself would neither contribute to the stability of the implant nor, if deformed, remain an effective barrier immediately beside the implant, where it is most important to prevent migration of unwanted cell types.

Ideally, the integrated guided-tissue-regeneration barrier, whether with a permanent or resorbable membrane, should be left in place after insertion, making re-entry surgery to remove it unnecessary. Not only would retrieval of the barrier be unrnecessary, but uncovering the implant would be as well. It is intended that the full-s thickness flap elevated to expose the bony site for integrated barrier placement be sutured around, not over, the implant cover screw. The cover screw would guide the gingival tissue to heal around it so that it would be continuously visible. It would be painlessly removable and replaceable without local anaesthetic when the time came to attach a prosthesis to the implant.
io Integrated barriers in combination with implants would be useful not only in fresh extraction sockets, but also in toothless sites with insufficient bone volume. Using them, bone augmentation, implant insertion and implant exposure could be accomplished with only two surgeries, one or two fewer than current techniques require. The reduction would be possible because the integrated barrier is would not be removed. The integrated barrier would also make the operations easier and faster for the surgeon.
The range of dental surgeons providing implants with integrated barriers immediately on extraction of teeth could encompass general dentists capable of the limited flap surgery required, as well as periodontists and oral surgeons. This 2o range is wider than the range of simple implant providers, and could potentially increase the number of patients who could benefit from implants with integrated GTR
barriers.

_7_ If priced correctly, immediate implants with integrated GTR barriers would be found preferable to extraction and bridging, complex root canal treatment and toothless spaces. By being low-cost, single-surgery, short-healing-time tooth replacements, they would be apt to make the public more familiar with the benefits and relative ease of implants in general, and would therefore be apt to increase the number of simple implants being placed in edentulous sites.
SUPJIMARY OF THE INVENTION
According to the invention, there is provided an integrated guided-tissue-io regeneration barrier to be attached to a root-form implant member of either screw-in or pre;>s-fit type. The barrier is composed of a membrane arranged to exclude soft tissue cell:;, a titanium reinforcement system, joining means for connecting the membrane to the reinforcement system and joining means for connecting the barrier to the root-form dental implant.
is The function of the integrated barrier is to make it possible for the implant portion of the implant-barrier combination to become osseointegrated after having been insE~rted in a tooth socket immediately after removal of a tooth. It will do this by decreasing the likelihood of movement of the implant in the extraction site and by preventing unwanted cell types fram entering and proliferating in the socket.
2o The integrated barrier is to be left permanently in place, in contrast with non-resorbable guided-tissue-regeneration barriers used to increase bone volume for implant insertion.

_$_ The dental implant-barrier combination, though most useful in fresh extraction sockets, could also be used in edentulous areas to induce bone growth to create increased bone volume where bone height or width were inadequate to envelope the implant.
Preferably, the barrier is composed of a light gauge sheet titanium spyder bonded either to titanium mesh or a resorbable membrane such as a bioabsorbable collagen membrane made of type I bovine tendon collagen, or composed solely of titanium mesh, all three constructions possessing biocompatibility, the malleability necessary to allow the barrier to be intimately adapted to the bony surface of the io alveolar crest and the possibility of being cut to final shape at the time of surgery.
The barrier may be pre-formed in order for it to conform to the shape of the bone of the maxillary or mandibular alveolar crest, thereby reducing the amount of manipulation needed during the surgical procedure in which it is inserted.
The means of joining the barrier membrane to the titanium reinforcement is spyder may comprise bonding with (for example) an epoxy or cyanoacrylate adhesive, welding (only with a titanium mesh barrier membrane) or embedding the titanium reinforcement spyder in the resorbable membrane during manufacturing.
The means of joining the barrier to the implant may comprise in situ insertion of the implant through the barrier after prior adaptation of the barrier to the 2o surrounding bone, so that the implant fits tightly in the opening provided for it in the barrier. Additionally, the joining means may, for press-fit implants, comprise welding, bonding with (for example) an epoxy or cyanoacrylate adhesive and press fitting into a _g_ groove the width of the thickness of the barrier. These additional means would be accomplished during the manufacturing process, before sterilization and packaging, rather than at the time of surgery. For screw-type implants, which must be rotated to be placed, the joining means may also comprise a titanium collar or ring which could rotate s in a race or groove in the implant, and to which the barrier could be attached so the implant could be screwed into place without the barrier rotating. This additional joining means would also be accomplished during the manufacturing process.
The above-mentioned collar could be made with a break in its circumference to allow it to be opened enough to be snapped into place in the groove io meant to accept it, or the implant could be made in two pieces, with the two being joined after' collar and mesh were in place.
The barrier may be pre-sterilized and packaged as a separate element, to remain so until removed from its package at the time of surgery, then cut to final shape and adapted to the bone surrounding the implant site, The implant-barrier combination is is created by the surgeon inserting the implant through the barrier after the barrier is in place in the surgical site.
Alternatively, the barrier and implant are joined to create the combination, then pre-sterilized and packaged. In this embodiment, the barrier-implant combination prefE~rably includes a removable handle in order for it to be manipulated without actually 2o being touched, so that when the surgeon removes the combination from its sterile packaging at the time of surgery, he can cut and shape the barrier without touching the impl<~nt member.

BRIEF DESCRIPTION OF THE FIGURES
Embodiments of the invention are shown in the accompanying drawings, in which:
s Figure 1 is a top view of an integrated guided-tissue-regeneration barrier attached to a root-form dental implant.
Figure 2 is a side view of an integrated guided-tissue-regeneration barrier attached to a root-form dental implant of press-fit design.
Figure 3 is an isometric view of an integrated guided-tissue-io regE~neration barrier attached to a root-form dental implant of press-fit design in a disposable sterile package.
Figure 4 is a schematic view of an integrated guided-tissue-regE~neration barrier attached to a root-form dental implant of press-fit design inserted in an immediate extraction socket.
is Figure 5 is a schematic view of an integrated guided-tissue-regE~neration barrier attached to a root-form dental implant of press-fit design inserted in an osteotomy (drilled out) site with inadequate bone volume and the barrier contoured to permit bone growth to fully imbed the implant.
Figure 6 is a schematic view of an osseointegrated press-fit implant with 2o an integrated guided-tissue-regeneration barrier attached to an abutment and a prosthetic tooth.
Figure 7 is a side view of an integrated guided-tissue-regeneration barrier attached to a screw-type implant.
Figure 8 is a side view of an integrated guided-tissue-regeneration barrier attached to a root-form dental implant of press-fit design in a disposable sterile package.
s Figure 9 is a isometric view of an integrated guided-tissue-regeneration barrier with no implant attached Figure 10 is an isometric view of a collared integrated guided-tissue-regeneration barrier made solely of titanium mesh.
Figure 11 is a top view of a collarless titanium mesh integrated guided-io tissue-regeneration barrier attached to a root-form dental implant.
Figure 12 is a cutaway side view of an integrated guided-tissue-regE:neration barrier attached to an implant of screw-in design.
In the drawings, like characters of reference indicate corresponding parts in the different figures, as denoted here:
is integrated guided-tissue-regeneration barrier attached to a root-form dental implant;
11 titanium reinforcement spyder;
12 barrier;
13 barrier membrane;
14 root-form dental implant;

15 implant cover screw;

16 tooth extraction socket;

17 abutment;

zs 18 gum;

19 prosthetic tooth;
20 bone;
21 disposable plastic sterile packaging;
22 area between barrier and bone in which bony infill is desired for implant s fixation;
24 raised collar on titanium reinforcement spyder;
26 groove in screw-type implant in which collar may rotate;
28 threads on screw-type implant;
30 disposable plastic handle.
io DETAILED DESCRIPTION
Referring to the drawings, an implant-barrier combination 10 is comprised of a root-form implant member 14, a barrier 12 and an implant cover screw 15.
The barrier 12 is arranged to stabilize the root-form implant member 14, is and to act as a barrier to soft tissue cells, as described below.
Specifically, the barrier 12 acts to exclude fibroblasts and epithelial cells from a tooth extraction socket 16. In this embodiment, the barrier 12 is composed of titanium mesh, specifically 100 x 100 mesh. It is of note that the titanium mesh is biocompatible and malleable as described below.
2o The implant member 14 of the implant-barrier combination 10 is arranged to be inserted into tooth extraction socket 16 as described below. The details of the implant member 14 are not shown as these are known to persons knowledgeable in the art.
The dental implant-barrier combination 10 is assembled by connecting the barrier 12 to the implant member 14 such that the barrier 12 extends outwardly from the implant member 14 as shown in Figures 1-8. In this embodiment, the barrier 12 is bonded to the implant member 14 with an epoxy adhesive. Alternatively, the barrier 12 may be connected to the implant member 14 by other means, for example, by welding s the (barrier 12 to the implant member 14. It is of note that, once assembled, the dental implant-barrier combination 10 may be sterilized and enclosed in sterile packaging 21 for later use, as shown in Figures 3 and 8. This in turn will greatly reduce the risk of bacterial contamination and surface contamination of the titanium surfaces of the barrier 12 and implant member 14.
io In an embodiment wherein the implant member 14 with threads 28 is arranged to be screwed into the extraction socket 16, the barrier 12 is attached to a colt<~r 24, which is arranged to be fitted into a circumferential groove 26 in the implant mernber 14. The collar 24, together with the attached barrier 12, may rotate in the groove 26 freely about the implant. member 14, or alternatively may be stationary while Is the implant member 14 is rotated while being screwed into the extraction socket 16.
In another embodiment shown in Figure 8, the dental implant-barrier combination 10 may include a removable handle 30 for aiding in manipulating the dental implant-barrier combination 10 during surgery.
In operation, before tooth extraction, the surgeon will evaluate the site 2o clinically and view its radiograph image to determine whether the tooth is replaceable with an implant-barrier combination 10, and if so, what implant member 14 size the implant-barrier combination 10 should have and how to cut and shape the mesh barrier 12. The surgeon will elevate the gum 20 about the tooth, remove the tooth, mechanically debride the socket 16, confirm or modify implant-barrier combination 10 choice and cut and contour the mesh barrier 12. The barrier 12 is sufficiently malleable that the barrier 12 may be formed into the necessary shape either prior to s surgery or during surgery as desired. Thus the barrier 12 may be readily manipulated so as to conform to the desired shape, a shape which it will retain. The surgeon will then insert the implant member 14 in the socket 16 and press the barrier 12 against the adjoining bone. The gum 20 will be sutured in place over the barrier 12 and around the implant cover screw 15, the repositioned gum 20 holding the mesh io barrier 12 firmly in place on the bone and the barrier 12 in turn helping to stabilize the implant member 14 by virtue of its rigid attachment to it. . As a result of the barrier 12 preventing migration of fibroblasts and epithelial cells into the extraction socket 16, osteoblasts populate the healing blood clot around the implant member 14, achieving oste~ointegration.
is The barrier 12 is composed of titanium mesh, is biocompatible and causes little risk of infection, as noted above. The titanium mesh will retain the desired shape and circulation can be established through it. Consequently, it will not penetrate the overlying gum 18 as polytetrafluoroethylene and titanium foil tend to do. ,4s a result of its biocompatibiliy, small risk of infection, shape retention and 2o possibility of establishment of circulation, the barrier 12 does not have to be removed in a subsequent surgical procedure.
Once osteointegration has occurred, an abutment 17 and a prosthetic tooth 19 can be attached to the implant member 14 An alternative embodiment of the invention is shown in Figure 9 of the dravvings, wherein an integrated guided-tissue-regeneration barrier for root-form dental implants is comprised of membrane material 13 and a titanium rib reinforcement system s 11. The titanium rib reinforcement system has a raised collar 24 of the same inside diameter as the outside diameter as the root-form dental implant 14 to hold the implant securely in place in the integrated barrier.
The membrane material may be either titanium mesh or a resorbable material such as a bioabsorbable collagen membrane made of type I bovine tendon io collagen. It is joined to the reinforcement ribbing with an adhesive such as epoxy or cyanoacrylate.
Figure 10 shows another embodiment in which the integrated guided-tissue-regeneration barrier is comprised solely of titanium mesh with the mesh formed into a raised collar around the opening for the root-form dental implant. The titanium is mesh is specifically 100 x 100 mesh. It is of note that the titanium mesh is biocompatible and malleable as described below. This embodiment would likely be strong enough only if bonded to the implant during the manufacturing process.
Figure 11 shows an embodiment in which the integrated guided-tissue-regeneration barrier is composed of titanium mesh with no collar and the opening for 2o the root-form dental implant is of a diameter slightly smaller than the outside diameter of the implant, but slightly larger than the diameter of a groove in the implant designed to have the mesh snap into it as the implant is pushed through the barrier. This embodiment as well would likely be strong enough only if bonded to the implant during the manufacturing process.
The integrated guided-tissue-regeneration barrier 12 is arranged to stabilize the root-form implant member 14, and to act as a barrier to soft tissue cells, as s described below. Specifically, the barrier membrane 13 acts to exclude fibroblasts and epithelial cells from a tooth extraction socket 16, as shown in Figure 4.
The implant member 14 of the implant-barrier combination is arranged to be inserted into a tooth extraction socket 16 as described below. The details of the implant member 14 are not shown as these are known to persons knowledgeable in the io art.
The integrated guided-tissue-regeneration barrier 12 may be attached to a root-form dental implant 14 prior to packaging, as in Figures 3 and 8, or at the time of surgery. Assembly is by connecting the implant member 14 to the barrier 12 such that the barrier 12 extends outwardly from the implant member 14 as shown in Figures 1-8.
is When the implant member 14 is inserted in the barrier at the time of surgery, the implant member is held in the barrier by the closeness of the fit of the barrier collar to the implant. In the embodiments shown in Figures 1 and 3 the implant member 14 is bonded to the barrier 12 with an epoxy adhesive. Alternatively, the implant member 14 may be connected to the barrier 12 by other means, for example, by welding the barrier 20 12 to the implant member 14. It is of note that, once assembled, the dental implant-barrier combination 10 may be sterilized and enclosed in sterile packaging 21 for later use, as shown in Figures 3 and 8. This in turn will greatly reduce the risk of bacterial contamination and surtace contamination of the barrier 12 and implant member In an embodiment illustrated in Figures 7 and 11, wherein the implant member 14 with threads 28 is arranged to be screwed into the extraction socket 16, the collar 24 of the integrated guided-tissue-regeneration barrier 12 is arranged to be fitted s into a circumferential groove 26 in the implant member 14. The integrated guided-tissue-regeneration barrier 12, may rotate in the groove 26 freely about the implant member 14, or alternatively may be stationary while the implant member 14 is rotated while being screwed into the extraction socket 16.
In another embodiment shown in Figure 8, the dental implant-barrier io combination 10 may include a removable handle 30 for aiding in manipulating the dental implant-barrier combination 10 during surgery.
In Oaeration with Insertion of the Implant Member in the Barrier at the Time of Suraery In operation, before tooth extraction, the surgeon evaluates the site is clinically and views its radiograph image to determine whether the tooth is replaceable with an implant-barrier combination 10, and if so, what implant member 14 size the implant-barrier combination 10 should have and how to cut and shape the integrated guided-tissue-regeneration barrier 12. The surgeon then elevates the gum 20 about the tooth, removes the tooth, mechanically debrides the socket 16, confirms 20 or modifies implant member 14 choice and cuts and contours the integrated guided-tissue-regeneration barrier 12. The barrier 12 is sufficiently malleable that it may be formed into the necessary shape either prior to surgery or during surgery as desired.

Thus the barrier 12 is readily manipulated so as to conform to the desired shape, a shape which it will retain. The surgeon then places the correctly shaped integrated guided-tissue-regeneration barrier 12 over the socket 16 and presses it firmly into place on the surrounding bone to complete its adaptation to the site. The surgeon s then inserts the implant member 14 in the socket 16 through the barrier 12.
The gum 20 is sutured in place over the barrier 12 and around the implant cover screw 15, the repositioned gum 20 holding the integrated guided-tissue-regeneration barrier firmly in place on the bone and the barrier 12 in turn helping to stabilize the implant member 14 by virtue of its tight fit to the implant member 14. As a result of the barrier io 12 preventing migration of fibroblasts and epithelial cells into the extraction socket 16, osteoblasts populate the healing blood clot around the implant member 14, achieving osteointegration.
In O~~eration with the Implant Member inserted in the Prior to Packa~inct is In operation when the guided-tissue-regeneration barrier is combined with the root-form dental implant in sterile packaging, the surgeon evaluates the site clinically before tooth extraction and views its radiograph image to determine whether the tooth is replaceable with an implant-barrier combination 10, and if so, what size implant member 14 the implant-barrier combination 10 should have and how to cut 2o and shape the integrated guided-tissue-regeneration barrier 12. The surgeon then elevates the gum 20 about the tooth, remove the tooth, mechanically debrides the socket 16, confirms or modifies implant member 14 choice and cuts and contours the integrated guided-tissue-regeneration barrier 12, taking care to hold the combination by the attached handle 30 so as not to touch or contaminate the implant member 14.
The surgeon places the implant-barrier combination 10 so that the implant member 14 is inserted in the socket 16 and the integrated guided-tissue-regeneration barrier s 12 is in position over the bone 20 around the socket 16. The surgeon then completes the adaptation of the integrated guided-tissue-regeneration barrier 12 to the alveolar bone by pressing it firmly against the bone 20. The gum 18 is sutured in place over the barrier 12 and around the implant cover screw 15, the repositioned gum 18 holding the integrated guided-tissue-regeneration barrier 12 firmly in place on the io bone 20 and the barrier 12 in turn helping to stabilize the implant member 14 by virtue of its tight fit to the implant member 14.
The barrier membrane 13 composed of titanium mesh or resorbable membrane material is biocompatible and causes little risk of infection, as noted above. The titanium mesh or resorbable membrane material bonded to titanium is reinforcement ribbing will retain the desired shape and circulation can be established through them. Consequently, it will not penetrate the overlying gum 18 as polytetrafluoroethylene and titanium foil tend to do. As a result of its biocompatibiliy, small risk of infection, shape retention and possibility of establishment of circulation, the integrated guided-tissue-regeneration barrier 12 does not have to be removed in 2o a subsequent surgical procedure.
Once osteointegration has occurred, an abutment 17 and a prosthetic tooth 19 can be attached to the implant member 14.

Since various modifications can be made in my invention as herein described, and many apparently widely different embodiments of the same made within the spirit and scope of the claims without departure from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.

Claims

1.~A dental implant-barrier combination comprising a root-form implant member of either screw-in or press-fit type, a barrier arranged to exclude soft tissue cells and joining means for connecting the barrier to the implant member.