Guided Tissue Regeneration in Endodontic Surgery by Using a Bioactive Resorbable Membrane C. Susan Chi, DMD, Diego B. Andrade, DDS, Sahng G. Kim, DDS, MS and Charles S. Solomon, DDS Abstract Introduction: Guided tissue regeneration is a valuable technique available to the endodontist because the quality, quantity, or extent of bone loss cannot be visu- alized by the surgeon until the tissue is reflected and the surgical site is exposed. Methods: After repeated at- tempts at nonsurgical treatment, a patient with a recur- ring sinus tract over the distobuccal root of an upper molar ultimately had the distobuccal root resected, leav- ing a 10 Â 10 mm bony defect. This dehiscence was filled with freeze-dried bone and covered with a flexible and absorbable bioactive membrane that was new to endodontics. Results: Healing was uneventful, and bone regeneration was rapid and extensive as observed at the time of a second surgery just 5 months later. This can be attributed at least in part to the use of the bioac- tive membrane that contains an array of growth factors that enhance cell proliferation, inflammation, recruit- ment of progenitor cells, and metalloproteinase activity. Conclusions: The use of the bioactive membrane in endodontic surgery should be considered to best restore the attachment apparatus to the tooth and prevent the downgrowth of a long junctional epithelium. The end- odontist’s attention must not be limited to the apical re- gion alone. (J Endod 2015;-:1–4) Key Words Bioactive membrane, endodontic surgery, guided tissue regeneration (GTR), long junctional epithelium, oot resection D uring the last 15 years, endodontists have refined their microsurgical techniques to the point where outcome studies now report success in the high 90th percentile (1, 2). This has been attributed to improved lighting, magnification, and cone-beam computed tomography (CT) as well as better microsurgical instruments that enhance the degranulation of lesions and the sealing of apices (3). From a periodontal perspec- tive, an apical lesion can be looked at as a 5- or 6-walled infrabony pocket and thus has a most favorable prognosis for bone regeneration after surgical resolution of the lesion, without periodontal guided tissue regeneration intervention. However, it is somewhat problematic when an apical lesion progresses coronally along the periodontal ligament, causing absorption of the radicular bony support and ultimately communicating with the periodontal pocket to create secondary periodontal issue (4). Before this occurs and while the pocket depths are still within normal limits, it is difficult to assess the quantity or quality of the bone overlying the buccal or labial aspects of the root. In this situation, a cone-beam CT scan might lead to a clearer picture for a more accurate diagnosis (5). Short of this, many surgical endodontic procedures should be ap- proached from an exploratory perspective, with a final disposition for a treatment plan that may or may not include guided tissue regeneration (GTR) made at the time of surgery (6). After a full-thickness flap is made, the epithelial tissue repairs more rapidly than the underlying connective tissue, and there is always the fear that a long functional epithelium will migrate down the root surface before there can be connective tissue re- attachment to the root, which may compromise the periodontal longevity of the tooth (4). The use of GTR by using bone fillers and membranes may be indicated to protect the existing bone and increase the regeneration of new bone and connective tissue. A new bioactive membrane (BioXclude; Snoasis Medical, Denver, CO), which is very thin (300 mm thick), absorbable, and derived from the human placenta that con- tains growth factors (7) that have been used for many years in external wound healing, has been adapted and Food and Drug Administration approved for oral use. After placing freeze-dried bone (70/30 mineralized/demineralized allograft blend) in the bony dehiscences, this flexible membrane tightly adapts to the underlying bone and root surfaces, precluding the downgrowth of long junctional epithelium and presum- ably leading to more rapid regeneration and healing. This membrane is a wound covering that is composed of allograft dehydrated human amnion chorion membrane (dHACM) (8). It needs no trimming and may be folded over onto itself. This processed dHACM contains angiogenic growth factors: angiogenin, angiogenin-2, epidermal growth factor, basic fibroblast growth factor, heparin-binding epidermal growth factor, platelet-derived growth factor BB, placenta growth factor, and vascular endothelial growth factor (9). In vitro, these soluble growth factors simulated the proliferation and migration of human microvascular endothelial cells and caused these cells to pro- duce and release all 30 tested angiogenic growth factors. In a different in vitro test, these soluble growth factors were shown to have a chemotatic effect on the migration of human umbilical vein endothelial cells. In vivo, vascularization of the allograft was demonstrated with a steady increase of microvessel formation at all time points (9). In addition, interleukin (IL-4, IL-6, IL-8, and IL-10) as well as tissue inhibitors of metalloproteinases (TIMP 1, TIMP 2, and TIMP 4) are present in dHACM. Laminins (glycoprotein), particularly laminin-5, are the major non-collagenous components of amnion/chorion tissue and have a strong affinity for cell migration and adhesion, which are so critical in regenerative procedures. The adhesive components in the From the Division of Endodontics, Columbia University Col- lege of Dental Medicine, New York, New York. Address requests for reprints to Dr Charles S. Solomon, Division of Endodontics, Columbia University College of Dental Medicine, 630 West 168th Street, New York, NY 10032. E-mail address: css5@columbia.edu 0099-2399/$ - see front matter Copyright ª 2015 American Association of Endodontists. http://dx.doi.org/10.1016/j.joen.2014.10.018 Case Report/Clinical Techniques JOE — Volume -, Number -, - 2015 Bioactive Absorbable Membrane in GTR 1