473
Bone
Regeneration Around a Failing Implant Using Guided Tissue Regeneration. A Case Report* Marc J. Goldman
be clinically and radiographically failing. The implant natural tooth with periodontal disease. The defect around the implant was degranulated and a polytetrafluoroethylene periodontal membrane placed over the implant to cover the defect. The membrane was removed 6 weeks later. A 5month re-entry found new bone around the implant and the implant could then be used as a prosthetic abutment. Further case studies may prove this to be a predictable procedure to save failing implants. J Periodontol 1992; 63:473-476.
An
was
implant was determined to
treated
as
Key Words:
if it
were a
Dental
implants; membranes; barrier; guided tissue regeneration.
guided tissue regeneration (GTR) was initially employed to regenerate new attatchement around periodontally involved teeth.1 A barrier, such as a non-resorbable polytetrafluoroethylene (PTFE) membrane, is ligated around the tooth and over the periodontal defect. The gingival flap The concept of
is sutured to cover the material. The membrane acts as a mechanical barrier to prevent the epithelium from migrating apically and thus allows the peridontal ligament cells to form new bone, new cememtum, and inserting collagen fibers. Within the past decade, there has also been a tremendous boom in the manufacture and use of dental implants to replace missing natural teeth. Brânemark2 first reported an intimate bone to implant contact. The predictability of titanium implants to achieve osseointegration3,4 has greatly enhanced the prosthetic options for patients who otherwise may have been committed to a removable prosthesis. Unfortunately, there is not a 100 percent success rate with any of the available implant systems.3"8 Early failures are those that occur within the healing or pre-loading stages. These failures may result from improper surgical procedures and/or premature functional loading from overlying removable dentures.7,8 Bacterial contamination has also been implicated for failing implants and these are the same Gramnegative anaerobic rods and spirochetes that have been associated with adult Periodontitis.8"10 GTR techniques have recently been used in conjunction with implants to increase the available height and width of alveolar bone in edentulous areas prior to implant placement.11'12 These ridges were formerly insufficient for implant installation. Other cases have been reported where GTR was used in
'Department of Dentistry,
Newark Beth Israel
Hospital, Newark,
NJ.
association with titanium dental implants placed in immediate extraction sites to generate new bone around the implants.1215 New bone formation was also evidenced at sites that had dehiscences present at the time of implant
insertion.1315
The purpose of this paper is to present an example of where the principles of GTR were used to form new bone around a failing implant. While the initial finding is gratifying, further cases will be required to demonstrate the validity of this procedure. CASE HISTORY A 45-year old black female was referred in March 1990 for implant placement in the mandibular right quadrant. The patient was edentulous in the maxillary arch. The 6 mandibular anterior teeth were present along with the mandibular left first molar. The patient had previously completed root planing and scaling by her general practitioner and no additional periodontal therapy was indicated. There was no bleeding on probing and pocket depth was 1 to 3 mm. Two Screw-Vent implants* were placed, a 7 mm fixture in the molar area and a 10 mm implant in the premolar
region. Healing was progressing uneventfully. The manufacturer suggests allowing 3 to 4 months for osseointergration in the mandible.16 The patient, however, did not present for second stage surgery to uncover the implants until October 1990, 7 months after the fixtures
were
placed.
On clinical examination, a fistula had developed over the anterior 10 mm-length fixture. There was no suppuration fCore Vent
Corporation, Encino, CA.
474
J Periodontol May 1992
BONE REGENERATION INDUCED AROUND A FAILING IMPLANT. A CASE REPORT
Figure 1. Pre-operative radiograph demonstrating radiolucency on distal of implant extending apically around and onto the mesial. 2. 3-walled instrumentation.
Figure
noted, but there
localized swelling. The patient gave this area. history A periapical radiograph (Fig. 1) revealed a radiolucency on the distal aspect that extended around the apex and onto the mesial of the implant. A flap was elevated to visualize the amount of destruction. Granulomatous tissue was curetted out of the defect by hand and ultrasonic instrumentation. It was the author's understanding, at the time, that only titanium instruments should come in contact with the implant surface. Therefore, every attempt was made to avoid contacting the titanium implant surfaces. On inspection, a 3-walled osseous defect was observed (Fig. 2). The implant was osseointegrated on the mesial aspect and was not mobile. A polytetrafluoroethylene periodontal membrane* was trimmed from one of the pre-formed shapes that were available. The barrier was tented over the site to completely cover the implant and the defect The flaps were tightly adapted with suture* material to obtain primary closure. The patient was prescribed Augmentin§ 250 mg tid for a week and instructed to rinse with a 0.12% Chlorhexidine solution11 twice a day throughout the time that the membrane was in place. The removable partial denture was adjusted to eliminate any pressure or premature loading on the implant sites. Six-weeks post-surgery, the membrane had become exposed. An incision was made on the crest of the ridge to remove the material. Sutures were placed to close the site and the patient was instructed to continue with Chlorhexidine rinses twice daily. The second stage of uncovering the implant occurred in no
circumferential defect
on
distal
of implant after
was
of pain
over
*W.L. Gore and Associates, Flagstaff, AZ. §Beecham Laboratories, Philadelphia, PA. iPeridex, Procter & Gamble, Cincinnati, OH.
Figure 3. Radiograph of implant 5 months after initial surgery. 1991. At this time, a periapical radiograph demonstrated an increase in radiopacity around the implant (Fig. 3). Elevation of full thickness mucoperiosteal flaps found that new bone had formed around the implant (Fig. 4). The fixture was immobile. The patient returned for a 6-month examination in November 1991, but had not started the prosthetic phase of therapy because of personal problems. Another periapical radiograph (Fig. 5) was taken, which demonstrated that the bone fill that was initially found was still present.
May
DISCUSSION Implant failure can result from
overheating the bone during placement, premature loading by overlying dentures, or
Volume 63 Number 5
GOLDMAN
475
chetes, Capnocytophaga, and black-pigmented Bacteriodes
associated with failing implants. These organisms have been previously associated with periodontal diseases. There were natural teeth remaining in the mandibular arch that had normal pocket depths of 1 to 3 mm and these teeth were clinically healthy. The gingiva was not inflamed, nor was there any bleeding or suppuration on probing. Since all the maxillary teeth had been lost presumably as a result of periodontal disease, these remaining teeth may have harbored pathogenic bacteria that could have been responsible for the lack of complete osseointegration of this fixture. Following the removal of the granulomatous tissue around the implant, a 3-walled infrabony defect was revealed (Fig. 2). If one treats this problem as if it were around a natural tooth, then this lesion need only be curetted to expose the bony walls and to achieve reattachment and bone fill.19,20 Since the defect continued around the apex of the implant, it was questionable if all the inflammatory tissue could, in Figure 4. Implant is
uncovered
to
reveal
new
bone formation.
fact, be removed.
The success in this specific instance may be that this type of defect in the alveolar bone lends itself to natural bone fill after degranulation. The elimination of the pathogenic microbiota by instrumentation and antibiotic therapy may also have accounted for the positive outcome. Theoretically, the bone loss around the implant was not due to bacteria, but caused by premature loading by the existing partial denture. Thus, it may be necessary to only remove the granulomatous tissue and relieve the pressure caused by the denture over the implant to obtain healing. The technique of using a membrane barrier has been utilized to correct periodontal defects, especially in the treatment of Class II furcation involvements.2123 Employing a PTFE membrane, bone formation has also been demonstrated around implants when they are placed into extraction sites, even where a dehiscence had occurred at the time of insertion.1215 Other applications of GTR have been to increase the height and width of edentulous ridges prior to
implant insertion.11,12
Figure 5. Radiograph
taken 6 months
after Figure 3. Bone fill is stable.
bacterial colonization.711 Quirynen and Listgarten17 suggested that the remaining natural teeth may serve as a reservoir for the bacterial colonization of titanium implants. In fully edentulous mouths, Listgarten and Helldén found more bacteria associated with "health," that is more coccoid cells, and less motile rods and spirochetes.18 While no bacterial samples were taken, in retrospect, this would have helped to determine if the defect around this failing implant was caused either by premature overloading of the existing denture or pathogenic microbiota. Mombelli et al.9 had isolated a large percentage of Gram-negative anaerobic rods consisting mainly of black-pigmented Bacteriodes and Fusobacterium from around failing implants. Other authors8,10 have additionally reported high populations of Actinobacillus actinomycetemcomitans, spiro-
To date, there have not been any reported cases where guided tissue regeneration has been used to save a failing implant. Based on the available literature at the time this procedure was performed, the author applied the principles of GTR to this particular situation. The eventual result was unpredictable. This initial case demonstrates that there is a potential for healing in certain instances where an implant is failing.
Further research and studies should determine whether the cause of the failure is dependent on pathological bacteria, premature loading of the implant, or a combination of both. Depending on which situation precipitates the breakdown around the fixture, then this may determine if treatment would be successful. This case report has established that the principles of GTR can be employed to salvage a failing implant. New bone had formed in the original defect and this fixture is now acceptable to be used as a prosthetic abutment.
476
BONE REGENERATION INDUCED AROUND A FAILING IMPLANT. A CASE REPORT
Unfortunately, the patient has not continued with the restorative phase of treatment; however, a radiograph (Fig. 5) taken 6 months after re-entering demonstrates that there has been no further alveolar bone loss around the implant. It would be advantageous to follow this implant after it has
been restored. With the increasing utilization of implants, there inevitably will be implants which do not initially osseointegrate or which fail after being loaded. Should this procedure described above prove to be effective and predictable in other cases of implant failures, it would enhance the success rate of implants. The ability to treat these implants similarly to natural teeth affected by periodontal disease would add a new dimension to both periodontology and implantology. REFERENCES 1. Gottlow J, Nyman S,
Linde J, Karring T, Wennström J. New attachformation in the human periodontium by guided tissue regeneration: Case reports. / Clin Periodontol 1986;13:604-616. 2. Brânemark PI, Breine U, Adell R, Hansson BO, Lindström J, Olsson A. Intra-osseous anchorage of dental prostheses. I. Experimental studies. Scand J Plast Recontr Surg 1969;3:81-100. 3. Adell R, Lekholm U, Rockler B, Brânemark PI. A 15-year study of osseointegrated implants in the edentulous jaw. Int J Oral Surg ment
1981;10:387^16. 4. Albrektsson T, Dahl E, Enborn L, et al. Osseointegrated oral implants. A Swedish multicenter study of 8139 consecutively inserted Nobelpharma implants. J Periodontol 1988;59:287-296. 5. Patrick D, Zosky J, Lubar R, Buchs A. The longitudinal clinical efficacy of Core-Vent dental implants: A five-year report. / Oral
Impiantai 1989;15:95-103. D, Weber HP, Lang NP. Tissue integration of non-submerged hollowimplants. 1 year results of a prospective study with 100 cylinder and hollow-screw implants. Clin Oral Implant Res 1990;1:33-
6. Buser
40. 7. Masters DH. Problem
solving
in
implant dentistry. J Am Dent Assn
1990;121:355-358. 8. Becker W, Becker BE, Newman MG, Nyman S. Clinical and micro9.
biologic findings that may contribute to dental implant failure. Int J Oral Maxillofac Implants 1990;5:31-38. Mombelli A, van Oosten MAC, Schurch E, Lang NP. The microbiota associated with successful or failing osseointegrated titantium implants. Oral Microbiol Immunol 1987;2:145-151.
J Periodontol May 1992
GAP, Feik D, Ram TE, Rosenberg ES, Slots J. Microbiology of failing osseointegrated implants. American Society of Microbiology Annual Meeting May 14—18, 1989; paper C382,
10. Alcoforado
page 457. 11. Buser D, Brägger U, Lang NP, Nyman S. Regeneration and enlargement of jaw bone using guided tissue regeneration. Clin Oral Impl Res 1990;1:22-32. 12. Nyman S, Lang NP, Buser D, Brâgger U. Bone regeneration adjacent to titanium dental implants using guided tissue regeneration: A report of two cases. Int J Oral Maxillofac Implants 1990;5:9-14. 13. Becker W, Becker BE. Guided tissue regeneration for implants placed into extraction sockets and for implant dehiscences: Surgical techniques and case reports. Int J Periodontics Restorative Dent
1990;10:377-391. TJ, Hernandez RE, Cutler RH, Hertzog CF. Treatment of osseous defects using Vicryl mesh (Polyglactin 910) and the Brânemark implant: A case report. Int J Oral Maxillofac Implants 1991;6:87-
14. Balshi
91. 15. Wilson TG Jr. Guided tissue regeneration around dental implants: A case report. Tex Dent J 1990;107:15-17. 16. Core-Vent Corporation. Spectra-System® Surgical Manual. Encino, CA:1990. 17. Quirynen M, Listgarten MA. The distribution of bacterial morphotypes around natural teeth and titanium implants ad modum Brânemark. Clin Oral Implant Res 1990;1:8-12. 18. Listgarten MA, Helldén L. Relative distribution of bacteria at clinically healthy and peridontally diseased sites in humans. / Clin Periodontol 1978;5:115-132. 19. Prichard JF. The regeneration of bone following periodontal therapy. Oral Surg 1957;10:247-252. 20. Prichard JF. The infrabony technique as a predictable procedure. J Periodontol 1957;28:202-216. 21. Pontoriero R, Nyman S, Linde J, Rosenberg E, Sanavi F. Guided tissue regeneration in the treatment of furcation defects in man. / Clin Periodontol 1987;14:618-620. 22. Pontoriero R, Linde J, Nyman S, Karring T, Rosenberg E, Sanavi F. Guided tissue regeneration in degree II furcation-involved mandibular molars. A clinical study. / Clin Periodontol 1988;15:247-254. 23. Lekovic V, Kenney EB, Kovacevic , Carranza FA Jr. Evaluation of guided tissue regeneration in grade II furcation defects. A clinical re-entry study. / Periodontol 1989;60:694-698.
Send reprint requests to: Dr. Marc Goldman, 116 Millburn Avenue, Millburn, NJ 07041-1985. Accepted for publication December 6, 1991.
Bone
Regeneration Around a Failing Implant Using Guided Tissue Regeneration. A Case Report* Marc J. Goldman
be clinically and radiographically failing. The implant natural tooth with periodontal disease. The defect around the implant was degranulated and a polytetrafluoroethylene periodontal membrane placed over the implant to cover the defect. The membrane was removed 6 weeks later. A 5month re-entry found new bone around the implant and the implant could then be used as a prosthetic abutment. Further case studies may prove this to be a predictable procedure to save failing implants. J Periodontol 1992; 63:473-476.
An
was
implant was determined to
treated
as
Key Words:
if it
were a
Dental
implants; membranes; barrier; guided tissue regeneration.
guided tissue regeneration (GTR) was initially employed to regenerate new attatchement around periodontally involved teeth.1 A barrier, such as a non-resorbable polytetrafluoroethylene (PTFE) membrane, is ligated around the tooth and over the periodontal defect. The gingival flap The concept of
is sutured to cover the material. The membrane acts as a mechanical barrier to prevent the epithelium from migrating apically and thus allows the peridontal ligament cells to form new bone, new cememtum, and inserting collagen fibers. Within the past decade, there has also been a tremendous boom in the manufacture and use of dental implants to replace missing natural teeth. Brânemark2 first reported an intimate bone to implant contact. The predictability of titanium implants to achieve osseointegration3,4 has greatly enhanced the prosthetic options for patients who otherwise may have been committed to a removable prosthesis. Unfortunately, there is not a 100 percent success rate with any of the available implant systems.3"8 Early failures are those that occur within the healing or pre-loading stages. These failures may result from improper surgical procedures and/or premature functional loading from overlying removable dentures.7,8 Bacterial contamination has also been implicated for failing implants and these are the same Gramnegative anaerobic rods and spirochetes that have been associated with adult Periodontitis.8"10 GTR techniques have recently been used in conjunction with implants to increase the available height and width of alveolar bone in edentulous areas prior to implant placement.11'12 These ridges were formerly insufficient for implant installation. Other cases have been reported where GTR was used in
'Department of Dentistry,
Newark Beth Israel
Hospital, Newark,
NJ.
association with titanium dental implants placed in immediate extraction sites to generate new bone around the implants.1215 New bone formation was also evidenced at sites that had dehiscences present at the time of implant
insertion.1315
The purpose of this paper is to present an example of where the principles of GTR were used to form new bone around a failing implant. While the initial finding is gratifying, further cases will be required to demonstrate the validity of this procedure. CASE HISTORY A 45-year old black female was referred in March 1990 for implant placement in the mandibular right quadrant. The patient was edentulous in the maxillary arch. The 6 mandibular anterior teeth were present along with the mandibular left first molar. The patient had previously completed root planing and scaling by her general practitioner and no additional periodontal therapy was indicated. There was no bleeding on probing and pocket depth was 1 to 3 mm. Two Screw-Vent implants* were placed, a 7 mm fixture in the molar area and a 10 mm implant in the premolar
region. Healing was progressing uneventfully. The manufacturer suggests allowing 3 to 4 months for osseointergration in the mandible.16 The patient, however, did not present for second stage surgery to uncover the implants until October 1990, 7 months after the fixtures
were
placed.
On clinical examination, a fistula had developed over the anterior 10 mm-length fixture. There was no suppuration fCore Vent
Corporation, Encino, CA.
474
J Periodontol May 1992
BONE REGENERATION INDUCED AROUND A FAILING IMPLANT. A CASE REPORT
Figure 1. Pre-operative radiograph demonstrating radiolucency on distal of implant extending apically around and onto the mesial. 2. 3-walled instrumentation.
Figure
noted, but there
localized swelling. The patient gave this area. history A periapical radiograph (Fig. 1) revealed a radiolucency on the distal aspect that extended around the apex and onto the mesial of the implant. A flap was elevated to visualize the amount of destruction. Granulomatous tissue was curetted out of the defect by hand and ultrasonic instrumentation. It was the author's understanding, at the time, that only titanium instruments should come in contact with the implant surface. Therefore, every attempt was made to avoid contacting the titanium implant surfaces. On inspection, a 3-walled osseous defect was observed (Fig. 2). The implant was osseointegrated on the mesial aspect and was not mobile. A polytetrafluoroethylene periodontal membrane* was trimmed from one of the pre-formed shapes that were available. The barrier was tented over the site to completely cover the implant and the defect The flaps were tightly adapted with suture* material to obtain primary closure. The patient was prescribed Augmentin§ 250 mg tid for a week and instructed to rinse with a 0.12% Chlorhexidine solution11 twice a day throughout the time that the membrane was in place. The removable partial denture was adjusted to eliminate any pressure or premature loading on the implant sites. Six-weeks post-surgery, the membrane had become exposed. An incision was made on the crest of the ridge to remove the material. Sutures were placed to close the site and the patient was instructed to continue with Chlorhexidine rinses twice daily. The second stage of uncovering the implant occurred in no
circumferential defect
on
distal
of implant after
was
of pain
over
*W.L. Gore and Associates, Flagstaff, AZ. §Beecham Laboratories, Philadelphia, PA. iPeridex, Procter & Gamble, Cincinnati, OH.
Figure 3. Radiograph of implant 5 months after initial surgery. 1991. At this time, a periapical radiograph demonstrated an increase in radiopacity around the implant (Fig. 3). Elevation of full thickness mucoperiosteal flaps found that new bone had formed around the implant (Fig. 4). The fixture was immobile. The patient returned for a 6-month examination in November 1991, but had not started the prosthetic phase of therapy because of personal problems. Another periapical radiograph (Fig. 5) was taken, which demonstrated that the bone fill that was initially found was still present.
May
DISCUSSION Implant failure can result from
overheating the bone during placement, premature loading by overlying dentures, or
Volume 63 Number 5
GOLDMAN
475
chetes, Capnocytophaga, and black-pigmented Bacteriodes
associated with failing implants. These organisms have been previously associated with periodontal diseases. There were natural teeth remaining in the mandibular arch that had normal pocket depths of 1 to 3 mm and these teeth were clinically healthy. The gingiva was not inflamed, nor was there any bleeding or suppuration on probing. Since all the maxillary teeth had been lost presumably as a result of periodontal disease, these remaining teeth may have harbored pathogenic bacteria that could have been responsible for the lack of complete osseointegration of this fixture. Following the removal of the granulomatous tissue around the implant, a 3-walled infrabony defect was revealed (Fig. 2). If one treats this problem as if it were around a natural tooth, then this lesion need only be curetted to expose the bony walls and to achieve reattachment and bone fill.19,20 Since the defect continued around the apex of the implant, it was questionable if all the inflammatory tissue could, in Figure 4. Implant is
uncovered
to
reveal
new
bone formation.
fact, be removed.
The success in this specific instance may be that this type of defect in the alveolar bone lends itself to natural bone fill after degranulation. The elimination of the pathogenic microbiota by instrumentation and antibiotic therapy may also have accounted for the positive outcome. Theoretically, the bone loss around the implant was not due to bacteria, but caused by premature loading by the existing partial denture. Thus, it may be necessary to only remove the granulomatous tissue and relieve the pressure caused by the denture over the implant to obtain healing. The technique of using a membrane barrier has been utilized to correct periodontal defects, especially in the treatment of Class II furcation involvements.2123 Employing a PTFE membrane, bone formation has also been demonstrated around implants when they are placed into extraction sites, even where a dehiscence had occurred at the time of insertion.1215 Other applications of GTR have been to increase the height and width of edentulous ridges prior to
implant insertion.11,12
Figure 5. Radiograph
taken 6 months
after Figure 3. Bone fill is stable.
bacterial colonization.711 Quirynen and Listgarten17 suggested that the remaining natural teeth may serve as a reservoir for the bacterial colonization of titanium implants. In fully edentulous mouths, Listgarten and Helldén found more bacteria associated with "health," that is more coccoid cells, and less motile rods and spirochetes.18 While no bacterial samples were taken, in retrospect, this would have helped to determine if the defect around this failing implant was caused either by premature overloading of the existing denture or pathogenic microbiota. Mombelli et al.9 had isolated a large percentage of Gram-negative anaerobic rods consisting mainly of black-pigmented Bacteriodes and Fusobacterium from around failing implants. Other authors8,10 have additionally reported high populations of Actinobacillus actinomycetemcomitans, spiro-
To date, there have not been any reported cases where guided tissue regeneration has been used to save a failing implant. Based on the available literature at the time this procedure was performed, the author applied the principles of GTR to this particular situation. The eventual result was unpredictable. This initial case demonstrates that there is a potential for healing in certain instances where an implant is failing.
Further research and studies should determine whether the cause of the failure is dependent on pathological bacteria, premature loading of the implant, or a combination of both. Depending on which situation precipitates the breakdown around the fixture, then this may determine if treatment would be successful. This case report has established that the principles of GTR can be employed to salvage a failing implant. New bone had formed in the original defect and this fixture is now acceptable to be used as a prosthetic abutment.
476
BONE REGENERATION INDUCED AROUND A FAILING IMPLANT. A CASE REPORT
Unfortunately, the patient has not continued with the restorative phase of treatment; however, a radiograph (Fig. 5) taken 6 months after re-entering demonstrates that there has been no further alveolar bone loss around the implant. It would be advantageous to follow this implant after it has
been restored. With the increasing utilization of implants, there inevitably will be implants which do not initially osseointegrate or which fail after being loaded. Should this procedure described above prove to be effective and predictable in other cases of implant failures, it would enhance the success rate of implants. The ability to treat these implants similarly to natural teeth affected by periodontal disease would add a new dimension to both periodontology and implantology. REFERENCES 1. Gottlow J, Nyman S,
Linde J, Karring T, Wennström J. New attachformation in the human periodontium by guided tissue regeneration: Case reports. / Clin Periodontol 1986;13:604-616. 2. Brânemark PI, Breine U, Adell R, Hansson BO, Lindström J, Olsson A. Intra-osseous anchorage of dental prostheses. I. Experimental studies. Scand J Plast Recontr Surg 1969;3:81-100. 3. Adell R, Lekholm U, Rockler B, Brânemark PI. A 15-year study of osseointegrated implants in the edentulous jaw. Int J Oral Surg ment
1981;10:387^16. 4. Albrektsson T, Dahl E, Enborn L, et al. Osseointegrated oral implants. A Swedish multicenter study of 8139 consecutively inserted Nobelpharma implants. J Periodontol 1988;59:287-296. 5. Patrick D, Zosky J, Lubar R, Buchs A. The longitudinal clinical efficacy of Core-Vent dental implants: A five-year report. / Oral
Impiantai 1989;15:95-103. D, Weber HP, Lang NP. Tissue integration of non-submerged hollowimplants. 1 year results of a prospective study with 100 cylinder and hollow-screw implants. Clin Oral Implant Res 1990;1:33-
6. Buser
40. 7. Masters DH. Problem
solving
in
implant dentistry. J Am Dent Assn
1990;121:355-358. 8. Becker W, Becker BE, Newman MG, Nyman S. Clinical and micro9.
biologic findings that may contribute to dental implant failure. Int J Oral Maxillofac Implants 1990;5:31-38. Mombelli A, van Oosten MAC, Schurch E, Lang NP. The microbiota associated with successful or failing osseointegrated titantium implants. Oral Microbiol Immunol 1987;2:145-151.
J Periodontol May 1992
GAP, Feik D, Ram TE, Rosenberg ES, Slots J. Microbiology of failing osseointegrated implants. American Society of Microbiology Annual Meeting May 14—18, 1989; paper C382,
10. Alcoforado
page 457. 11. Buser D, Brägger U, Lang NP, Nyman S. Regeneration and enlargement of jaw bone using guided tissue regeneration. Clin Oral Impl Res 1990;1:22-32. 12. Nyman S, Lang NP, Buser D, Brâgger U. Bone regeneration adjacent to titanium dental implants using guided tissue regeneration: A report of two cases. Int J Oral Maxillofac Implants 1990;5:9-14. 13. Becker W, Becker BE. Guided tissue regeneration for implants placed into extraction sockets and for implant dehiscences: Surgical techniques and case reports. Int J Periodontics Restorative Dent
1990;10:377-391. TJ, Hernandez RE, Cutler RH, Hertzog CF. Treatment of osseous defects using Vicryl mesh (Polyglactin 910) and the Brânemark implant: A case report. Int J Oral Maxillofac Implants 1991;6:87-
14. Balshi
91. 15. Wilson TG Jr. Guided tissue regeneration around dental implants: A case report. Tex Dent J 1990;107:15-17. 16. Core-Vent Corporation. Spectra-System® Surgical Manual. Encino, CA:1990. 17. Quirynen M, Listgarten MA. The distribution of bacterial morphotypes around natural teeth and titanium implants ad modum Brânemark. Clin Oral Implant Res 1990;1:8-12. 18. Listgarten MA, Helldén L. Relative distribution of bacteria at clinically healthy and peridontally diseased sites in humans. / Clin Periodontol 1978;5:115-132. 19. Prichard JF. The regeneration of bone following periodontal therapy. Oral Surg 1957;10:247-252. 20. Prichard JF. The infrabony technique as a predictable procedure. J Periodontol 1957;28:202-216. 21. Pontoriero R, Nyman S, Linde J, Rosenberg E, Sanavi F. Guided tissue regeneration in the treatment of furcation defects in man. / Clin Periodontol 1987;14:618-620. 22. Pontoriero R, Linde J, Nyman S, Karring T, Rosenberg E, Sanavi F. Guided tissue regeneration in degree II furcation-involved mandibular molars. A clinical study. / Clin Periodontol 1988;15:247-254. 23. Lekovic V, Kenney EB, Kovacevic , Carranza FA Jr. Evaluation of guided tissue regeneration in grade II furcation defects. A clinical re-entry study. / Periodontol 1989;60:694-698.
Send reprint requests to: Dr. Marc Goldman, 116 Millburn Avenue, Millburn, NJ 07041-1985. Accepted for publication December 6, 1991.
