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Clinical Human
Comparison of Expanded Polytetrafluoroethylene Barrier Membrane and Freeze-Dried Dura Mater Allografts for Guided Tissue Regeneration of Lost Periodontal Support. I. Mandibular Molar Class II
Furcations* Raymond A. The
Yukna
Class II facial furcations to guided tissue regeneration with expanded polytetrafluoroethylene barrier membrane (e-PTFE) or freezedried dura mater allograft (FDDMA) barriers was evaluated in 11 pairs of molars in 11 patients. Following initial preparation, full thickness flaps were raised in the area being treated, the bone and furcation defects debrided of granulomatous tissue, and the involved root surfaces mechanically and chemically prepared. By random allocation, e-PTFE or FDDMA barriers were fitted over the furcations, secured in place, and the host flap repositioned or coronally positioned. Postsurgical deplaquing was performed every 10 days leading up to e-PTFE removal at about 6 weeks (the resorbable FDDMA did not require removal). Continuing supportive periodontal therapy was provided until surgical re-entry at one year for documentation and any further necessary treatment. Direct clinical measurements demonstrated essentially similar clinical results with both barrier materials for bone and soft tissue changes (few statistically or clinically significant differences). Exceptions were the amount of horizontal furcation fill and the change in the width of the keratinized gingiva, both of which were better with FDDMA (P 1 mm or 1 furcation class used to determine comparative superiority or inferiority of particular treatment in each patient. fDifference of > 15% used to determine comparative superiority or inferiority of particular treatment in each patient.
associated with the use of the two barriers under study. It can be seen that responses were generally equal between the 2 materials, except for less frequent horizontal bone fill, lack of improvement in clinical furcation grade, and more frequent adverse effect on the zone of keratinized gingiva with e-PTFE. Intrapatient comparisons are shown in Table 6. e-PTFE was generally less effective in achieving horizontal furcation fill or improving the clinical furcation grade than was FDDMA in a given patient.
436
COMPARISON OF TEFLON AND DURA MATER IN FURCATIONS
J Periodontol May 1992
2. Tooth #18 furcation treated with e-PTFE and tooth #19 furcation treated with FDDMA. A. Initial Class II furcation defects following defect debridement and root preparation. B. Placement of e-PTFE barrier on tooth #18 and FDDMA barrier on tooth #19. C. 10 day postsurgical condition showing slight clinical exposure of both barriers. D. Clinical view of e-PTFE barrier tooth #18 at removal at 6 weeks. e-PTFE barrier intact with gingival tissue easily displaced from barrier. E. Clinical view of FDDMA barrier tooth #19 at 6 weeks. Remnants of FDDMA evident adjacent to and covering furcation area. Gingival tissue easily displaced from barrier.
Figure
No signs of root résorption were noted in any of the treated teeth. No discernible changes were noted on visual comparison of pretreatment and one year posttreatment
radiographs.
There were minimal postsurgical problems using these barriers except for the occurrence of a buccal space infection in 3 patients associated with the presence of and external to the e-PTFE material.69 These were managed with local drainage, in-office irrigation, and systemic administration of penicillin (250 mg QID) until the e-PTFE was
removed. This phenomenon did not appear to affect the healing between the e-PTFE and the tooth. There were no similar infections associated with the FDDMA barriers. Premature exposure of the e-PTFE membrane occurred in 6 of the 11 cases while similar exposure of the FDDMA barrier occurred in 1 of the 11 cases. Occasionally, adjacent teeth were treated with each material and this allowed a view of the FDDMA site during e-PTFE removal. In general, the FDDMA appeared to be intact at 6 weeks (Fig. 2E). There was no identifiable
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Figure 2. Continued. F. Six-week barrier removal view demonstrating newly formed tissue filling furcation of both teeth, with no apparent clinical differences. Open probing attachment level substantially improved with both treatments. G. Clinical view 8 weeks after e-PTFE removal and surgical "exposure" of FDDMA. H. One year re-entry photograph demonstrating limited repair of both furcations. Note crestal bone loss on midroot areas of both teeth. FDDMA barrier material evident at the one year reentry. Clinical examples are shown in Figures 2 through 4.
DISCUSSION The results of this study suggest that both e-PTFE and FDDMA used as GTR barriers yield generally favorable clinical results in mandibular Class II furcations, and that there are essentially no differences in results between the 2 materials. This was particularly true regarding hard tissue findings of defect fill and crestal résorption, and somewhat less so for soft tissue findings such as gingival recession and changes in the width of keratinized gingiva. Results obtained with other types of defects will be reported
subsequently.
No instances of complete furcation closure with either soft attached tissue or re-formed hard tissue were found in this study37 (Fig. 1). Several others have shown the new velvety, red granulation tissue evident at e-PTFE removal at or coronal to the CEJ.28-32-37 While this phenomenon was also seen in this study, the "new attachment" tissue receded and regressed toward the initial levels over the next several months37 (Table 4). In general, the clinical findings relative to furcation fill and gain in clinical attachment are less positive than those reported in other studies using both e-PTFE and resorbable
materials.2-23'28"32'34-35 It is difficult
to explain these differsimilar Class II mandibular facial furcation defects were treated and the published protocol for e-PTFE use was followed. One reason for the difference may be the more detailed and specific evaluation performed in this study, which accounted for the response of all of the tissues of the periodontium both in the immediate furcation area as well as at the adjacent mid-root locations. The combination of crestal résorption on the adjacent roots and some fill of the furcations would yield a more "parabolic physiologic form" that would appear more pleasing and more favorable clinically.70 72 This may mislead some into believing that the results from the GTR therapy was better than it actually was when specifically measured. Another consideration may be the criteria used to judge complete furcation fill.28>30>32-34 In this study, complete fill meant that no concave root surface was evident at the fornix of the furcation at reentry (i.e., the newly repaired tissues were attached to the root trunk). Using this criterion, complete furcation fill did not occur in this group of patients treated with these modalities (Fig. 1). However, if a 1 mm "dimple" is accepted as an intact furcation, then 23% of those sites treated with each type of barrier became closed. This finding is similar to some reports,17'28'32,35-37'38 but differs from others.30'34 ences as
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COMPARISON OF TEFLON AND DURA MATER IN FURCATIONS
J Periodontol May 1992
3. M/67/C. Tooth #18 treated with FDDMA barrier and tooth #19 treated with e-PTFE barrier. A. Class II facial furcations evident on both teeth at initial surgery following defect debridement and root preparation. B. Clinical view at 6 week e-PTFE barrier removal and extension ofpartial thickness incision on tooth #18. Improvement in open probing attachment level in furcation evident for both teeth. C. Furcation condition at 1 year re-entry demonstrating limited change in furcations. Crestal résorption evident on adjacent roots, more so on #19.
Figure
The clinical findings and clinical appearance of the tissues during the various stages of healing are reminiscent of those following the classic push-back procedure.73-77 The exuberant initial formation of new tissue from the periodontal ligament and the eventual shrinkage or settling of that tissue to a position about 1 mm coronal to the original attachment, the net crestal bone résorption of 1 mm or more, and the generally favorable esthetic clinical topographical appearance of the tissues with both the push back and GTR techniques suggest that the latter may be simply a fancy, more involved, and more expensive push back, at least when not using a bone replacement graft. The improved closed probing attachment levels (CPAL) and "open" probing attachment levels (OPAL) were not associated with parallel improvements in bone levels. There did appear to be dense connective tissue that apparently did not convert to bone at 12 months in this study, just as it had not at 6 months in other studies.8'31·35'37·38 A particularly interesting finding was the dramatic improvement in OPAL evident at the time of e-PTFE removal, sometimes actually at or coronal to the CEJ. However, in the intervening months until the one year reentry, this attachment level regressed to a point that approximated the original attachment level.37 (Table 4) This same informa-
tion was not available for the FDDMA sites, as that resorbable material was not removed. In the areas where the e-PTFE and FDDMA treated teeth were adjacent to each other, occasional clinical observation of the young reparative tissue beneath the FDDMA remnants could be viewed and appeared similar to that under the removed e-PTFE
(Figs. 2F, 3B).
Other reports utilizing GTR have also experienced a universal lack of complete35-37-38 or only occasional true complete fill;28.3o,32,34 ^mt fjrj m manciibular Class II facial furcations; lack of crestal apposition or evidence of crestal résorption;17-35-38 gingival recession;31-32'35-38 regression of gained vertical and horizontal clinical probing attachment over time;37 and lack of bone fill.31-35 Most other reports that performed a reentry evaluation used a partial thickness flap aimed at evaluating the soft tissue attachment, and did not go to bone.31'32 This type of evaluation would account for response of only a portion of the periodontium. Reentry surgery may have removed "attached healed" tissues, and so may have altered some of the "open" measurements. However, the primary goal of this study was to evaluate the changes in the bone of the furcation and adjacent defects. A major clinical question has to be whether partial results
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Figure 4. F/57/C. Tooth #18 furcation treated with e-PTFE barrier and tooth #31 furcation treated with FDDMA barrier. A. Clinical condition of tooth #18 at initial surgery following defect debridement and root preparation. B. e-PTFE barrier in place. C. View at 6-week e-PTFE removal demonstrating improved open probing attachment level in furcation and on adjaceni roots. D. One-year surgical re-entry view shows loss of open probing attachment level apparent at e-PTFE removal and evidence of overall net loss of bone. E. Condition of tooth #31 at initial surgery following defect debridement and root preparation.
in mandibular Class II facial furcations, such as shown here and by others,28'32-35'37-38 actually improve the prognosis of the tooth. Many times, the repair resulted in a shallowmoderate Class II furcation rather than a deep Class II furcation. It is doubtful whether this actually changes the patient's or dental professional's ability to perform adequate plaque control in that region. If complete clinical closure of the furcations were a routine reality as suggested by some, then this type of GTR treatment would be an advantage and most beneficial. If, however, results follow the
pattern found in this study and others,28,32'35'37'38 then
one
of GTR barriers in furcation must question Similar worsening of horizontal furcation atmanagement. tachment levels over extended follow-up periods has also been shown for the modified Widman flap.78 No minimum width of keratinized gingiva was required for entry into the study, nor was there a requirement for soft tissue coverage of the furcation opening at the time of surgery. There was no substantial or significant correlation of either of these conditions with the results observed. Simthe routine
use
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COMPARISON OF TEFLON AND DURA MATER IN FURCATIONS
Figure 4. Continued. F. FDDMA barrier secured in place. Only slight eresiai résorption noted.
G.
One-year surgical re-entry demonstrating limited fill of furcation
shaped, then sutured into place as a single surface barrier.15'17 This differs from the more common use by the author of FDDMA as a rubber dam tent without sutures which may provide a better biologic seal.1-13-16 Some reports utilizing FDDMA
as a barrier have placed it at the of bone and have apically positioned the host flap leaving the FDDMA purposely uncovered14,15'17 thereby mitigating somewhat the barrier function of the material. Biological materials have certain drawbacks as well. Use of autogenous gingival grafts most often requires a second surgical wound on the palate with attendant increased morbidity.80 Allogeneic soft tissues from tissue banks are readily available, off-the-shelf materials, but they cany a remote possibility of disease transfer16,51 and may have inconsistent dimensions, texture, and resorbability of tissue pieces. It would appear, however, that dense collagen sheets may provide a less traumatic means of achieving guided tissue regeneration to enhance the regeneration of lost periodontal supporting tissues since a second surgical procedure is not necessary. Some patients and clinicians may select artificial rather than natural barriers for GTR procedures because of concern over the possibility of disease transfer with freezedried human tissue. Properly procured and tested human allograft tissues have a very low risk of disease transfer. With appropriate precautions as used by quality tissue banks, the risk of disease transmission has been estimated to be less than 1 in 1,667,600.51 This minimal risk would likely be reduced even further by the lyophilization and sterilization processes used. This study was performed to evaluate the two barrier materials without the use of ancillary bone graft materials. It is suggested from other studies that such combination treatment may be more beneficial than using barriers or epithelial exclusion techniques alone.32,38,81 While the biologic principles of GTR appear to be well established, particularly in animals, results in actual clin-
ical
use
may be very variable,
a
and associated
point
defects.
also made
others.2,8,28,31,32,35,37,40 It would appear that
by
more exten-
sive evaluation of the GTR procedure using different materials with and without bone replacement grafts is warranted.
crest
Acknowledgment
The administrative and organizational support of Catherine Ramey, Charlotte Yukna, and Kathleen Pfeiffer were vital to the completion of this project. In addition, the clinical assistance of Terrie Taylor and Michelle Mattox, bibliographic verification provided by Elizabeth Strother, statistical advice by Dr. William Gibson and staff, and the manuscript preparation efforts of Candee Lambert and Wyonna Halladay are appreciated and recognized. This study was supported by a grant from W. L. Gore & Associates and by the University of Miami Tissue Bank, which provided supplies and subsidization for this study. All of the treatment was performed in the private practice of the author, and all analyses and conclusions were made independently by him.
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2. Gottlow J, Nyman S, Lindhe J, Karring T, Wennstrom J. New attachment formation in the human periodontium by guided tissue regeneration. Case reports. J Clin Periodontol 1986;13:604-616. 3. Becker W, Becker BE, Prichard JF, Caffesse R, Rosenberg E, GianGrasso J. Root isolation for new attachment procedures. A surgical and suturing method: Three case reports. /Periodontol 1987;58:819826. 4. Fleisher N, DeWaal H, Bloom A. Regeneration of lost attachment apparatus in the dog using Vicryl absorbable mesh (polyglactin 910). Int J Periodontics Restorative Dent 1988;8(2):45-55. 5. Blumenthal NM. The use of collagen membranes to guide regeneration of new connective tissue attachment in dogs. J Periodontol
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Volume 63 Number 5 6. Card SJ, Caffesse RG, Smith BA, Nasjleti CE. New attachment following the use of a resorbable membrane in the treatment of Periodontitis in dogs. Int J Periodontics Restorative Dent 1989;9:58-69. 7. Niederman R, Savitt ED, Heeley JD, Duckworth JE. Regeneration of furca bone using Gore-Tex periodontal material. Int JPeriodontics Restorative Dent 1989;9:469-480. 8. Stahl SS, Froum S, Tarnow D. Human histologie responses to guided tissue regenerative techniques in intrabony lesions. / Clin Periodontal
1990;17:191-198. 9. Fleischer N, Kon S, Calalang M. Regeneration of lost attachment apparatus in the monkey using Vicryl absorbable mesh. J Periodontal 1991;62:84 (Res. Forum Abstr.). 10. Lekovic VM, Kenney EB. Dimitrijevic BB, Carranza FA Jr. Histometric and stereometric evaluation of new attachment formation following controlled tissue regeneration using four different membranes. J Periodontal 1991;62:85 (Res Forum Abstr.). 11. Kon S, Ruben MP, Bloom AB, Mardam-Bey W, Boffa M. Regeneration of periodontal ligament using resorbable and non-resorbable membranes: Clinical, histological, and histometric study in dogs. Int J Periodontics Restorative Dent 1991;11:59-71. 12. Ellegaard B, Karring T, Löe H. New periodontal attachment procedure based on retardation of epithelial migration. J Clin Periodontal
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13. Diel WB, Yukna RA. New periodontal attachment based on retardation of epithelial migration via freeze-dried skin allografts. J Dent Res 1982;61(Spec. Issue):234(Abstr. 500). 14. Busschop J, De Boever J. Clinical and histological characteristics of lyophilized allogenic dura mater in periodontal bony defects in humans. J Clin Periodontal 1983;10:399-411. 15. Garrett S, Loos B, Chamberlain D. Egelberg J. Treatment of intraosseous periodontal defects with a combined adjunctive therapy of citric acid conditioning, bone grafting, and placement of collagenous membranes. / Clin Periodontal 1988;15:383-389. 16. Zaner DJ, Yukna RA, Malinin TI. Human freeze-dried dura mater allografts as a periodontal biological bandage. / Periodontol
1989;60:617-623.
17. Garrett S, Martin M, Egelberg J. Treatment of periodontal furcation defects. Coronally positioned flaps versus dura mater membranes in Class II defects. J Clin Periodontol 1990;17:179-185. 18. Magnusson I, Batich C, Collins BR. New attachment formation following controlled tissue regeneration using biodegradable membranes. J Periodontol 1988;59:1-6. 19. Pitaru S, Tal H, Soldinger M, Grosskopf A, Noff M. Partial regeneration of periodontal tissues using collagen barriers. Initial observations in the canine. J Periodontol 1988;59:380-386. 20. Pitaru S, Tal H, Soldinger M, Noff M. Collagen membranes prevent apical migration of epithelium and support new connective tissue attachment during periodontal wound healing in dogs. J Periodont Res
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1989;24:247-253. Chung KM, Salkin LM, Stein MD, Freedman AL. Clinical evaluation of a biodegradable collagen membrane in guided tissue regeneration.
J Periodontol 1990;61:732-736. Nyman S, Gottlow J, Karring T, Lindhe J. The regenerative potential of the periodontal ligament. An experimental study in the monkey. J
Clin Periodontol 1982;9:257-265.
23.
Nyman S, Lindhe J, Karring T, Rylander H. New attachment following surgical treatment of human periodontal disease. J Clin Perio-
dontol 1982;9:290-296.
24. Aukhil I, Simpson DM, Schaberg TV. An experimental study of new attachment procedure in beagle dogs. J Periodont Res 1983;18:643654. 25. Gottlow J, Nyman S, Karring T, Lindhe J. New attachment formation as the result of controlled tissue regeneration. J Clin Periodontol
1984;11:494-503. 26. Magnusson I, Nyman S, Karring T, Egelberg J. Connective tissue attachment formation following exclusion of gingival connective tis-
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sue and epithelium during healing. J Periodont Res 1985;20;201208. 27. Pettersson EC, Aukhil I. Citric acid conditioning of roots affects guided tissue regeneration in experimental periodontal wounds. J Periodont Res 1986;21:543-552. 28. Cortellini P, Pini Prato G, Baldi C, Clauser C: Guided tissue regeneration with different materials. Int J Periodontics Restorative Dent
1990;10:137-151. 29. Caffesse RG, Smith BA, Castelli WA, Nasjleti CE.: New attachment achieved by guided tissue regeneration in beagle dogs. / Periodontol
1988;59:589-594.
30. Pontoriero R, Lindhe J, Nyman S, Karring T, Rosenberg E, Sanavi F. Guided tissue regeneration in degree II furcation involved mandibular molars. A clinical study. J Clin Periodontol 1988;15:247-254. 31. Becker W, Becker BE, Berg L, Prichard J, Caffesse R, Rosenberg E. New attachment after treatment with root isolation procedures: Report for treated Class III and Class II furcations and vertical osseous defects. Int J Periodontics Restorative Dent 1988;8(3):8-23. 32. Schallhorn RG, McClain PK. Combined osseus composite grafting, root conditioning, and guided tissue regeneration. Int J Periodontics Restorative Dent 1988;8(4):8-31 33. Claffey N, Motsinger S, Ambruster J, Egelberg J. Placement of a porous membrane underneath the mucoperiosteal flap and its effect on periodontal wound healing in dogs. J Clin Periodontol 1989;16:12-16. 34. Pontoriero R, Lindhe J, Nyman S, Karring T, Rosenberg E, Sanavi F. Guided tissue regeneration in the treatment of furcation defects in mandibular molars. J Clin Periodontal 1989;16:170-174. 35. Lekovic V, Kenney EB, Kovacevic , Carranza FA Jr. Evaluation of guided tissue regeneration in Class II furcation defects: A clinical re-entry study. / Periodontol 1989;60:694-698. 36. Caffesse RG, Domínguez LE, Nasjleti CE, Castelli WA, Morrison EC, Smith . Furcation defects in dogs treated by guided tissue regeneration (GTR). J Periodontol 1990;61:45-50. 37. Caffesse RG, Smith BA, Duff B, Morrison EC, Merrill D, Becker W: Class II furcations treated by guided tissue regeneration in humans: Case reports. J Periodontol 1990;61:510-514. 38. Lekovic V, Kenney EB, Carranza FA Jr, Danilovic V. Treatment of Class II furcation defects using porous hydroxypatite in conjunction with a polytetrafluoroethylene membrane. J Periodontol 1990;61:575578. 39. Quiñones CR, Catón JG, Poison AM, Wagener CJ, Mota LF, Laskaris B. Evaluation of a synthetic biodegradable barrier to facilitate guided tissue regeneration in interproximal sites. J Periodontol 1991;62:86(Res. Forum Abstr.). 40. Galgut PN. Guided tissue regeneration: Observations from five treated cases. Quintessence Int 1990;21:713-721. 41. Galgut PN, Oxidized cellulose mesh used as a biodegradable barrier membrane in the technique of guided tissue regeneration. A case report. J Periodontol 1990;61:766-768. 42. Ellegaard B, Nielson IM, Karring T. Lyodura grafts in new attachment procedures. J Dent Res 1976;55(Spec. Issue):305(Abstr. 975). 43. Carroll PB, Tow HD, Vernino AR. The use of allogeneic freeze-dried skin grafts in the oral environment. Oral Surg Oral Med Oral Pathol
1974;37:163-174.
44. Yukna RA, Tow HD, Carroll PB, Vernino AR, Bright RW. Evaluation of the use of freeze-dried skin allografts in the treatment of human mucogingival problems. / Periodontol 1977;48:187-193. 45. Yukna RA, Tow HD, Carroll PB, Vernino AR, Bright RW. Comparative clinical evaluation of freeze-dried skin allografts and autogenous gingival grafts in humans. / Clin Periodontol 1977;4:191-199. 46. Reuther JF, Wagner R, Braun . Experimental study on the free transplantation of mucosa and lyophilized dura to the oral cavity. J
47.
Maxillofac Surg 1978;6:64-69. Nayot C, Beagrie GS. An assessment of the biocompatability of "Lyodura" in the oral mucosa of the hamster. / Periodontol 1978;49:181-188.
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48. Bartolucci EG. A clinical evaluation of freeze-dried homologous dura mater as a periodontal free graft material: Study in humans. J Periodontol 1981;52:354-361. 49. Yukna RA, Turner DW, Robinson I_J. Variable antigenicity of lyophilized allogeneic and lyophilized xenogeneic skin in guinea pigs. J Periodont Res 1977;12:197-203. 50. Gher ME, Williams JE, Vernino AR, Strong DM, Pelleu GB Jr. Evaluation of the immunogenicity of freeze-dried skin allografts in humans. J Periodontol 1980;51:571-577. 51. Buck BE, Malinin T, Brown MD. Bone transplantation and human immunodeficiency virus. Clin Orthoped 1988;240:129-136. 52. Takei HH. Treatment of furcation involvement and combined periodontal-endodontic therapy. In: Carranza FA Jr, ed. Glickman's Clinical Periodontology. Philadelphia: W.B. Saunders, Co., 1990;860861. 53. Hamp SE, Nyman S, Lindhe J. Periodontal treatment of multirooted teeth; results after 5 years. / Clin Periodontol 1975;2:126-135. 54. O'Leary TJ, Drake RB, Naylor JE. The plaque control record. J Periodontol 1972;43:38. 55. Matia JI, Bissada NF, Maybury JE, Ricchetti P. Efficiency of scaling of the molar furcation area with and without surgical access. Int J Periodontics Restorative Dent 1986;6(6):25-35. 56. Boyko GA, Brunette DM, Melcher AH. Cell attachment to demineralized root surfaces in vitro. J Periodont Res 1980;15:297-303. 57. Pitaru S, Aubin JE, Gray A, Metzger , Melcher AH. Cell migration attachment and orientation in vitro are enhanced by partial demineralization of dentine and cementum and inhibited by bacterial endotoxin. J Periodont Res 1984;19:661-665. 58. Wikesjö UME, Baker PJ, Christersson LA, et al. A biochemical approach to periodontal regeneration. Tetracycline HCl treatment conditions dentin surfaces. J Periodont Res 1986;21:322-329. 59. Terranova VP, Franzetti LC, Hic S, et al. A biochemical approach to periodontal regeneration: Tetracycline treatment of dentin promotes fibroblast adhesion and growth. J Periodont Res 1986;21:330-337. 60. Pitaru S, Melcher AH. Organization of an oriented fiber system in vitro by human gingival fibroblasts attached to dental tissue: Relationship between cells and mineralized and demineralized tissue. J Periodont Res 1987;22:6-13. 61. Machtet EE, Christersson LA, Goulding M, Dunford R, Genco RJ. Effect of tetracycline root preparation on guided tissue regeneration in furcation defects. / Dent Res 1991;70(Spec. Issue):467(Abstr. 1611). 62. Ciancio SG, Mather ML, Kazmierczak MD: Effectiveness of systemic antibiotics in a barrier method of periodontal regeneration. / Dent Res 1990;69(Spec. Issue): 165(Abstr. 452). 63. Sweeney KC, Malloy RB, Yukna RA. Effect of zinc supplementation on bone regeneration following decalcified freeze-dried bone allografts. J Dent Res 1979;58(Spec. Issue):431(Abstr. 1364). 64. Williamson CE, Yukna RA, Gandor DW. Zinc concentration in normal and healing gingival tissues in beagle dogs. / Periodontol
1984;55:170-174.
65.
Rosling B, Nyman S, Lindhe J. The effect of systematic plaque conon bone regeneration in infrabony pockets. / Clin Periodontol
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1976;3:38-53.
66. Yukna RA, Broxson AW, Mayer ET, Brite DV. Comparison of Listerine mouthwash and periodontal dresing following periodontal flap surgery. I. Initial findings. Clin Prev Dent 1986;8(4):14-19. 67. Zambón JJ, Ciancio SG, Mather ML, Charles CH. The effect of an antimicrobial mouthrinse on early healing of gingival flap wounds. J Periodontol 1989;60:31-34. 68. Sanz M, Newman MG, Anderson L, Matoska W, Otomo-Corgel J, Saltini C. Clinical enhancement of post-periodontal surgical therapy by a 0.12% Chlorhexidine gluconate mouthrinse. J Periodontol
1989;60:570-576.
69.
Selvig KA, Nilveus RE, Fitzmorris L, Kersten B, Khorsandi SS. Scanning election microscopic observations of cell population and bacterial contamination of membranes used for guided tissue regen-
eration in humans. J Periodontol 1990;61:515-520. 70. Donnenfeld OW, Hoag PM, Weissman DP. A clinical study on the effects of osteoplasty. J Periodontol 1970;41:131-141. 71. Wood DL, Hoag PM, Donnenfeld OW, Rosenfeld LD. Alveolar crest reduction following full and partial thickness flaps. J Periodontol
1972;43:141-144.
72.
73. 74.
75.
Moghaddas H, Stahl SS. Alveolar bone remodeling following osseous surgery. A clinical study. J Periodontol 1980;51:376-381. Goldman HM, Schluger S, Fox L. Periodontal Therapy. St. Louis: The C.V. Mosby Co.; 1956:223-231. Bohannan HM. Studies in the alteration of vestibular depth. I. Complete denudation. J Periodontol 1962;33:120-128. Pfeifer JS. The growth of gingival tissue over denuded bone. J Per-
iodontol 1963;34:10-16. 76. Carrara JJ, Carranza, FA Jr, Albano EA, Joly GG. Effect of bone denudation in mucogingival surgery in humans. J Periodontol
1964;35:463-466.
77. Costich ER, Ramfjord SP. Healing after partial denudation of the alveolar process. J Periodontol 1968;39:127-134. 78. Kalkwarf KL, Kaidahl WB, Patii KD. Evaluation of furcation region response to periodontal therapy. / Periodontol 1988;59:794-804. 79. Klinge , Nilveus R, Kiger RD, Egelberg J. Effect of flap placement and defect size on healing of experimental furcation defects. J Periodont Res 1981;16:236-248. 80. Zingale JA. Observations on free gingival autografts. J Periodontol
1974;45:748-759.
81. Bowers GM, Chadroff B, Carnevale R, et al. Histologie evaluation of new attachment apparatus formation in human. Part II. J Periodontol 1989;60:675-682. Send reprint requests to: Dr. Raymond A. Yukna, Periodontics Department, School of Dental Medicine, University of Pittsburgh, 3501 Terrace St., Pittsburgh, PA 15262. Accepted for publication December 13, 1991.
Clinical Human
Comparison of Expanded Polytetrafluoroethylene Barrier Membrane and Freeze-Dried Dura Mater Allografts for Guided Tissue Regeneration of Lost Periodontal Support. I. Mandibular Molar Class II
Furcations* Raymond A. The
Yukna
Class II facial furcations to guided tissue regeneration with expanded polytetrafluoroethylene barrier membrane (e-PTFE) or freezedried dura mater allograft (FDDMA) barriers was evaluated in 11 pairs of molars in 11 patients. Following initial preparation, full thickness flaps were raised in the area being treated, the bone and furcation defects debrided of granulomatous tissue, and the involved root surfaces mechanically and chemically prepared. By random allocation, e-PTFE or FDDMA barriers were fitted over the furcations, secured in place, and the host flap repositioned or coronally positioned. Postsurgical deplaquing was performed every 10 days leading up to e-PTFE removal at about 6 weeks (the resorbable FDDMA did not require removal). Continuing supportive periodontal therapy was provided until surgical re-entry at one year for documentation and any further necessary treatment. Direct clinical measurements demonstrated essentially similar clinical results with both barrier materials for bone and soft tissue changes (few statistically or clinically significant differences). Exceptions were the amount of horizontal furcation fill and the change in the width of the keratinized gingiva, both of which were better with FDDMA (P 1 mm or 1 furcation class used to determine comparative superiority or inferiority of particular treatment in each patient. fDifference of > 15% used to determine comparative superiority or inferiority of particular treatment in each patient.
associated with the use of the two barriers under study. It can be seen that responses were generally equal between the 2 materials, except for less frequent horizontal bone fill, lack of improvement in clinical furcation grade, and more frequent adverse effect on the zone of keratinized gingiva with e-PTFE. Intrapatient comparisons are shown in Table 6. e-PTFE was generally less effective in achieving horizontal furcation fill or improving the clinical furcation grade than was FDDMA in a given patient.
436
COMPARISON OF TEFLON AND DURA MATER IN FURCATIONS
J Periodontol May 1992
2. Tooth #18 furcation treated with e-PTFE and tooth #19 furcation treated with FDDMA. A. Initial Class II furcation defects following defect debridement and root preparation. B. Placement of e-PTFE barrier on tooth #18 and FDDMA barrier on tooth #19. C. 10 day postsurgical condition showing slight clinical exposure of both barriers. D. Clinical view of e-PTFE barrier tooth #18 at removal at 6 weeks. e-PTFE barrier intact with gingival tissue easily displaced from barrier. E. Clinical view of FDDMA barrier tooth #19 at 6 weeks. Remnants of FDDMA evident adjacent to and covering furcation area. Gingival tissue easily displaced from barrier.
Figure
No signs of root résorption were noted in any of the treated teeth. No discernible changes were noted on visual comparison of pretreatment and one year posttreatment
radiographs.
There were minimal postsurgical problems using these barriers except for the occurrence of a buccal space infection in 3 patients associated with the presence of and external to the e-PTFE material.69 These were managed with local drainage, in-office irrigation, and systemic administration of penicillin (250 mg QID) until the e-PTFE was
removed. This phenomenon did not appear to affect the healing between the e-PTFE and the tooth. There were no similar infections associated with the FDDMA barriers. Premature exposure of the e-PTFE membrane occurred in 6 of the 11 cases while similar exposure of the FDDMA barrier occurred in 1 of the 11 cases. Occasionally, adjacent teeth were treated with each material and this allowed a view of the FDDMA site during e-PTFE removal. In general, the FDDMA appeared to be intact at 6 weeks (Fig. 2E). There was no identifiable
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Figure 2. Continued. F. Six-week barrier removal view demonstrating newly formed tissue filling furcation of both teeth, with no apparent clinical differences. Open probing attachment level substantially improved with both treatments. G. Clinical view 8 weeks after e-PTFE removal and surgical "exposure" of FDDMA. H. One year re-entry photograph demonstrating limited repair of both furcations. Note crestal bone loss on midroot areas of both teeth. FDDMA barrier material evident at the one year reentry. Clinical examples are shown in Figures 2 through 4.
DISCUSSION The results of this study suggest that both e-PTFE and FDDMA used as GTR barriers yield generally favorable clinical results in mandibular Class II furcations, and that there are essentially no differences in results between the 2 materials. This was particularly true regarding hard tissue findings of defect fill and crestal résorption, and somewhat less so for soft tissue findings such as gingival recession and changes in the width of keratinized gingiva. Results obtained with other types of defects will be reported
subsequently.
No instances of complete furcation closure with either soft attached tissue or re-formed hard tissue were found in this study37 (Fig. 1). Several others have shown the new velvety, red granulation tissue evident at e-PTFE removal at or coronal to the CEJ.28-32-37 While this phenomenon was also seen in this study, the "new attachment" tissue receded and regressed toward the initial levels over the next several months37 (Table 4). In general, the clinical findings relative to furcation fill and gain in clinical attachment are less positive than those reported in other studies using both e-PTFE and resorbable
materials.2-23'28"32'34-35 It is difficult
to explain these differsimilar Class II mandibular facial furcation defects were treated and the published protocol for e-PTFE use was followed. One reason for the difference may be the more detailed and specific evaluation performed in this study, which accounted for the response of all of the tissues of the periodontium both in the immediate furcation area as well as at the adjacent mid-root locations. The combination of crestal résorption on the adjacent roots and some fill of the furcations would yield a more "parabolic physiologic form" that would appear more pleasing and more favorable clinically.70 72 This may mislead some into believing that the results from the GTR therapy was better than it actually was when specifically measured. Another consideration may be the criteria used to judge complete furcation fill.28>30>32-34 In this study, complete fill meant that no concave root surface was evident at the fornix of the furcation at reentry (i.e., the newly repaired tissues were attached to the root trunk). Using this criterion, complete furcation fill did not occur in this group of patients treated with these modalities (Fig. 1). However, if a 1 mm "dimple" is accepted as an intact furcation, then 23% of those sites treated with each type of barrier became closed. This finding is similar to some reports,17'28'32,35-37'38 but differs from others.30'34 ences as
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COMPARISON OF TEFLON AND DURA MATER IN FURCATIONS
J Periodontol May 1992
3. M/67/C. Tooth #18 treated with FDDMA barrier and tooth #19 treated with e-PTFE barrier. A. Class II facial furcations evident on both teeth at initial surgery following defect debridement and root preparation. B. Clinical view at 6 week e-PTFE barrier removal and extension ofpartial thickness incision on tooth #18. Improvement in open probing attachment level in furcation evident for both teeth. C. Furcation condition at 1 year re-entry demonstrating limited change in furcations. Crestal résorption evident on adjacent roots, more so on #19.
Figure
The clinical findings and clinical appearance of the tissues during the various stages of healing are reminiscent of those following the classic push-back procedure.73-77 The exuberant initial formation of new tissue from the periodontal ligament and the eventual shrinkage or settling of that tissue to a position about 1 mm coronal to the original attachment, the net crestal bone résorption of 1 mm or more, and the generally favorable esthetic clinical topographical appearance of the tissues with both the push back and GTR techniques suggest that the latter may be simply a fancy, more involved, and more expensive push back, at least when not using a bone replacement graft. The improved closed probing attachment levels (CPAL) and "open" probing attachment levels (OPAL) were not associated with parallel improvements in bone levels. There did appear to be dense connective tissue that apparently did not convert to bone at 12 months in this study, just as it had not at 6 months in other studies.8'31·35'37·38 A particularly interesting finding was the dramatic improvement in OPAL evident at the time of e-PTFE removal, sometimes actually at or coronal to the CEJ. However, in the intervening months until the one year reentry, this attachment level regressed to a point that approximated the original attachment level.37 (Table 4) This same informa-
tion was not available for the FDDMA sites, as that resorbable material was not removed. In the areas where the e-PTFE and FDDMA treated teeth were adjacent to each other, occasional clinical observation of the young reparative tissue beneath the FDDMA remnants could be viewed and appeared similar to that under the removed e-PTFE
(Figs. 2F, 3B).
Other reports utilizing GTR have also experienced a universal lack of complete35-37-38 or only occasional true complete fill;28.3o,32,34 ^mt fjrj m manciibular Class II facial furcations; lack of crestal apposition or evidence of crestal résorption;17-35-38 gingival recession;31-32'35-38 regression of gained vertical and horizontal clinical probing attachment over time;37 and lack of bone fill.31-35 Most other reports that performed a reentry evaluation used a partial thickness flap aimed at evaluating the soft tissue attachment, and did not go to bone.31'32 This type of evaluation would account for response of only a portion of the periodontium. Reentry surgery may have removed "attached healed" tissues, and so may have altered some of the "open" measurements. However, the primary goal of this study was to evaluate the changes in the bone of the furcation and adjacent defects. A major clinical question has to be whether partial results
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Figure 4. F/57/C. Tooth #18 furcation treated with e-PTFE barrier and tooth #31 furcation treated with FDDMA barrier. A. Clinical condition of tooth #18 at initial surgery following defect debridement and root preparation. B. e-PTFE barrier in place. C. View at 6-week e-PTFE removal demonstrating improved open probing attachment level in furcation and on adjaceni roots. D. One-year surgical re-entry view shows loss of open probing attachment level apparent at e-PTFE removal and evidence of overall net loss of bone. E. Condition of tooth #31 at initial surgery following defect debridement and root preparation.
in mandibular Class II facial furcations, such as shown here and by others,28'32-35'37-38 actually improve the prognosis of the tooth. Many times, the repair resulted in a shallowmoderate Class II furcation rather than a deep Class II furcation. It is doubtful whether this actually changes the patient's or dental professional's ability to perform adequate plaque control in that region. If complete clinical closure of the furcations were a routine reality as suggested by some, then this type of GTR treatment would be an advantage and most beneficial. If, however, results follow the
pattern found in this study and others,28,32'35'37'38 then
one
of GTR barriers in furcation must question Similar worsening of horizontal furcation atmanagement. tachment levels over extended follow-up periods has also been shown for the modified Widman flap.78 No minimum width of keratinized gingiva was required for entry into the study, nor was there a requirement for soft tissue coverage of the furcation opening at the time of surgery. There was no substantial or significant correlation of either of these conditions with the results observed. Simthe routine
use
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COMPARISON OF TEFLON AND DURA MATER IN FURCATIONS
Figure 4. Continued. F. FDDMA barrier secured in place. Only slight eresiai résorption noted.
G.
One-year surgical re-entry demonstrating limited fill of furcation
shaped, then sutured into place as a single surface barrier.15'17 This differs from the more common use by the author of FDDMA as a rubber dam tent without sutures which may provide a better biologic seal.1-13-16 Some reports utilizing FDDMA
as a barrier have placed it at the of bone and have apically positioned the host flap leaving the FDDMA purposely uncovered14,15'17 thereby mitigating somewhat the barrier function of the material. Biological materials have certain drawbacks as well. Use of autogenous gingival grafts most often requires a second surgical wound on the palate with attendant increased morbidity.80 Allogeneic soft tissues from tissue banks are readily available, off-the-shelf materials, but they cany a remote possibility of disease transfer16,51 and may have inconsistent dimensions, texture, and resorbability of tissue pieces. It would appear, however, that dense collagen sheets may provide a less traumatic means of achieving guided tissue regeneration to enhance the regeneration of lost periodontal supporting tissues since a second surgical procedure is not necessary. Some patients and clinicians may select artificial rather than natural barriers for GTR procedures because of concern over the possibility of disease transfer with freezedried human tissue. Properly procured and tested human allograft tissues have a very low risk of disease transfer. With appropriate precautions as used by quality tissue banks, the risk of disease transmission has been estimated to be less than 1 in 1,667,600.51 This minimal risk would likely be reduced even further by the lyophilization and sterilization processes used. This study was performed to evaluate the two barrier materials without the use of ancillary bone graft materials. It is suggested from other studies that such combination treatment may be more beneficial than using barriers or epithelial exclusion techniques alone.32,38,81 While the biologic principles of GTR appear to be well established, particularly in animals, results in actual clin-
ical
use
may be very variable,
a
and associated
point
defects.
also made
others.2,8,28,31,32,35,37,40 It would appear that
by
more exten-
sive evaluation of the GTR procedure using different materials with and without bone replacement grafts is warranted.
crest
Acknowledgment
The administrative and organizational support of Catherine Ramey, Charlotte Yukna, and Kathleen Pfeiffer were vital to the completion of this project. In addition, the clinical assistance of Terrie Taylor and Michelle Mattox, bibliographic verification provided by Elizabeth Strother, statistical advice by Dr. William Gibson and staff, and the manuscript preparation efforts of Candee Lambert and Wyonna Halladay are appreciated and recognized. This study was supported by a grant from W. L. Gore & Associates and by the University of Miami Tissue Bank, which provided supplies and subsidization for this study. All of the treatment was performed in the private practice of the author, and all analyses and conclusions were made independently by him.
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81. Bowers GM, Chadroff B, Carnevale R, et al. Histologie evaluation of new attachment apparatus formation in human. Part II. J Periodontol 1989;60:675-682. Send reprint requests to: Dr. Raymond A. Yukna, Periodontics Department, School of Dental Medicine, University of Pittsburgh, 3501 Terrace St., Pittsburgh, PA 15262. Accepted for publication December 13, 1991.
