The free soft tissue graft has been a mainstay of periodontal therapy since the 1960s. It has been used to increase the zone of attached gingiva, cover exposed roots, and thicken a thin biotype tissue around both natural teeth and dental implants. While palatal tissue has been traditionally used, human freeze-dried skin procured from tissue banks, known as acellular dermal matrix (ADM), has been used with great success in the above procedures. As techniques of guided bone regeneration (GBR) have emerged, various types of resorbable and non-resorbable membranes have contributed to successful regeneration. The case reports presented below successfully used ADM as a barrier membrane, offering an alternative to traditional membranes.
Overview of Research and Therapeutic Approaches
Since the mid and late 1960s, soft tissue grafting has been used to increase the zone of attached gingiva, correct recession on exposed roots, and augment thin biotype tissue. The work of Sullivan and Atkins in 1968 and 1969 led to multiple techniques now used to treat various soft tissue deficiencies.1,2 The work of Langer and Langer in 1985 and in 19933,4 led to numerous other works by McGuire, Cordioli, and numerous others validating the connective tissue graft in periodontal plastic surgery.5-9 Among a number of disadvantages to the free soft tissue graft may be a difference in color matching, leaving what can sometimes resemble a scar, as well as the need to open a second site to acquire the donor tissue. While tissue can be taken from other areas of the mouth such as the tuberosity or an edentulous area, clinicians are often limited by the amount of tissue that can be harvested at one sitting due to anatomic considerations such as a small mouth, flat palatal vault, or vascular considerations. Many skilled operators who can harvest connective tissue in minimally invasive ways from the palate are often rebuffed by patients who are reluctant to have their palates entered, especially if they have had a prior traumatic procedure involving past gingival grafting.
Fortunately, some alternate therapies exist to procure needed tissue for soft tissue grafting where needed. ADM has been used in medical applications for years in reconstructive surgeries, both medical and dental, to repair or replace damaged skin or skin-like tissues. It is procured from a tissue bank and is made from collagen, elastin, and laminin and undergoes a process to remove cells that could cause tissue rejection or infection. In medicine, it is used in breast reconstruction, hernia repair, and burn therapy. Donor screening is rigorous, as the material from a donor is processed at the most highly vetted tissue banks. The tissue mesh acts as a scaffold for the patient’s own cells to grow into. Studies have shown a high degree of success and patient satisfaction in treating gingival recession and in obtaining root coverage as part of a connective tissue graft with or without a tunnel technique. It is excellent for patients needing multiple teeth or implants grafted when adequate gingival tissue is lacking or the patient is opposed to a palatal intervention. A study by Thakare et al. in 2015 compared 30 patients aged 18 to 50 with multiple Miller class I and II recessions.10 The study concluded that root coverage was as good as or better with a coronally advanced flap (CAF) plus acellular dermal matrix allograft (ADMA) versus CAF plus subepithelial connective tissue graft (SCTG) when comparing root coverage and other parameters of gingival health.
While clinicians have their own preferences for procuring tissue for grafting, certain advantages of using ADM include the ability to avoid a second surgical site, to achieve color match, to provide an excellent quantity of tissue, and to overcome some shrinkage by using thicker and larger pieces of ADM. The author has used ADM in combination with guided bone regeneration procedures as a barrier membrane. In the cases presented below, one case will show its efficacy in grafting and sealing the sulcus around a failing implant. In the other case, ADM was used to graft an explanted implant site and regenerate a ridge for future implant placement. In both cases, healthy tissues were obtained, in the first case enabling the patient to maintain an existing failing implant and, in the second case, to regenerate a ridge in preparation for reimplantation. In both cases, excellent vestibular depth was obtained. This article aims to examine the potential role of ADM as an alternative treatment option for guided bone regeneration and to contribute to future research in this area.
The following cases incorporate principles of GBR while simultaneously enhancing the peri-implant tissues around the failing implant in case 1, and while also augmenting the ridge and treating the exposed implant threads in case 2.
While we typically rely on membranes, both resorbable and non-resorbable, for guided bone regeneration, the use of ADM offers advantages in tissue reconstruction while acting as a barrier membrane. While ADM is not useful in vertical augmentation where a reinforced membrane is indicated, it has many other advantages. Recent articles by Yoon Jeong Kim et al.11 and Anthony Neely et al.12 deal with enhancing soft-tissue around dental implants and management of retrograde peri-implantitis using guided bone regeneration, respectively. Using ADM can be used to obtain similar results.
The author has used both palatal tissue and ADM extensively and has found that it is often possible to treat multiple deficiencies using ADM while avoiding a palatal incision. Harvesting palatal tissue can be problematic if the need for donor tissue arises and the patient is not compliant or has not provided prior consent. The supply of ADM is consistent, the color match is favorable, and various thicknesses are available. Although ADM is rarely used alone as the outer tissue covering the bone graft, thicker ADM may be used to enclose narrow infrabony defects when insufficient gingival tissue is available for flap closure. Assuming an adequate periosteal blood supply, it is possible to augment both hard and soft tissue in a single procedure.
Analysis and Treatment Rationale
Case 1: A 73-year-old female patient presented with an implant in the No. 21 position (lower left 1st premolar) (Figure 1). Radiographs of the implants did not show the 6 mm to 7 mm pocket on the facial that was revealed on probing.
The medical history of the patient was unremarkable for her age, with no contraindications to treatment. The implant had been in place for over 10 years and was well integrated. Probing depths had increased over the years, but the implant had no mobility and pain was nonexistent. Her choices were to do nothing, attempt to repair with guided bone regeneration, attempt to seal the pocket, or reposition the tissue for better maintenance. Given these choices, the patient opted for one surgical intervention rather than immediate removal of the implant.
Since there was no pocketing on the mesial, distal, and lingual, it was felt that the implant would be maintainable with any degree of successful treatment. After administration of 2 cartridges of lidocaine with epinephrine 1:100,000, an incision was made from Nos. 20 to 22 (2nd premolar to canine), and a full-thickness flap was reflected, allowing for visualization of the entire defect (Figure 2). Because the implant was slightly recessed and within the alveolar housing, a decision was made to detoxify the exposed threads with phosphoric acid gel (ideally 30% to 40%). Because the intention was to use GBR, it was not necessary to alter the implant threads since the threads would be subgingival and not exposed for plaque removal. Bone regeneration was accomplished with a 50:50 mixture of calcium apatite particles and freeze-dried demineralized bone to utilize both the osteo-inductive and conductive properties of the graft. Many other graft materials, including autogenous bone, could also have been used. Decortication of the surrounding bone was performed to enhance the local blood supply prior to graft placement (Figure 3).
Because of the thinness of the flap, it was decided to use ADM tissue as a membrane over the implant to augment the gingival tissue (Figure 4). Because a full-thickness flap was used, it was not possible to suture the ADM to the interdental papilla as used in a connective tissue graft. Instead, multiple 4-0 chromic gut sutures, both vertical and sling, were used to cover the bone and overlying ADM (Figure 5). At 2 weeks, some ADM is visible, but this is just tissue turning over and not infection (Figure 6). At 6 weeks, the tissue looks healthy, and the patient can perform normal hygiene procedures (Figure 7). At 2 years, the final healing reveals tightly adapted tissue that can’t be probed without tearing the gingiva (Figure 8). Is there true bone regeneration? Only a re-entry will tell, and even a CBCT scan may not be 100% accurate. However, the implant is functioning well, and the patient has no complaints.
Case 2: A 31-year-old female patient in distress called the office, complaining of severe pain in her lower front jaw. Two endosseous implants had been placed in the anterior mandible 6 days prior by another practitioner, and the patient was undergoing an unusual, rapid breakdown of the flap. Sutures were unraveling, and exposed threads were visible on one of the implants (Figure 9). The patient was in severe pain, and the treating dentist was out of town, so we were called upon to treat her emergency. The patient’s health was unremarkable for diabetes, immunocompromise, systemic disease, or a blood dyscrasia, and the patient was generally in good health. The rapid breakdown was highly unusual but required definitive treatment considering the state of the surgical site.
The gingiva was edematous and erythematous, and the sutures were prematurely unraveling, exposing underlying bone and the threads of the implant (Figure 9). Under local anesthesia with lidocaine and epinephrine 1:100,000, a full-thickness flap was reflected over the anterior mandibular ridge from approximately canine to canine, revealing multiple exposed threads on both implants with severe facial bone loss on implant No. 26 (lower right lateral incisor). Because the No. 23 implant (lower left lateral incisor) was stable and had fewer facial threads exposed, it offered the possibility of guided bone regeneration to retain the implant (Figure 10). Implant No. 26 was explanted due to rapid loss of bone on the facial and the likelihood that GBR was not an option (Figure 11). The anterior ridge was decorticated to increase vascularity, and a 50:50 mixture of calcium apatite and freeze-dried demineralized bone was placed over the ridge and in the explanted socket (Figure 12).
ADM was used as a barrier membrane for guided bone regeneration because there was insufficient gingival tissue to achieve primary closure of the grafted ridge. The ADM, while occlusive, ultimately breaks down to a mesh, allowing nutrients to pass through its pores while still serving as a barrier during the healing phase (Figure 13).
After undermining the facial flap and releasing the periosteum, it was apparent that a tension-free closure could not be attained. More tension would create pressure on the graft and create a shallow vestibule and probably compromise the GBR procedure. It was opted for tension-free silk sutures utilizing the ADM as a barrier and partial cover on the ridge (Figure 14). While there appeared to be little vestibular depth on closing, healing at 8 weeks was surprising. A ridge and attached gingiva was forming (Figure 15). At 18 weeks healing was excellent, with a fully formed alveolar ridge ready for reimplantation (Figure 16 and Figure 17). This was confirmed by probing under anesthesia. The patient chose to have her original practitioner replace the lost implant under general anesthesia, and the author was advised the procedure went well.
Conclusion
In the cases presented, ADM use resulted in satisfactory regeneration, maintenance of healthy attached tissue, and tension-free closure. The ability to augment the deficient gingiva is unique while creating space for bone regeneration. Traditional membranes as we use them function as barriers and rarely contribute to new gingival architecture. As an adjunct in GBR, this offers additional advantages, complementing traditional membranes. Further investigation by experienced practitioners may help to explore and expand the use of ADM in surgical procedures.
ADM provides a scaffold that facilitates the growth of new tissue while encouraging cell migration and proliferation. It also encourages neovascularization and the formation of new blood vessels, which supply oxygen and nutrients to the healing wound while nourishing newly formed tissue. This can only aid in the process of guided bone regeneration and may contribute more to the process than a less active resorbable collagen or polytetrafluoroethylene (PTFE) membrane.
Laurence Jay Levine, DDS
Periodontics and Implant Dentistry,
Henderson and Las Vegas, Nevada
References
1. Utilization of grafts in the Treatment of Gingival Recession Harley C Sullivan DDS Joseph H Atkins DDS MS Periodontics August 1968
2. Harley Sullivan DDS Joseph Atkins The role of Free Gingival Grafts in Periodontal Therapy Dental Clinics of North America Volume 13, Issue 1. January 1969 pgs. 133-148
3. Subepithelial Connective Tissue Graft Technique for Root Coverage Burton Langer, Laureen Langer December 1985 Journal of Periodontology/ Volume 12/pp715-720
4. The subepithelial connective tissue graft for treatment of gingival recession L Langer et al Dent Clinics of North America 1993 April
5. Pandit et al Comparison of two techniques of harvesting connective tissue and its effects on healing pattern at the palate on recession coverage at the recipient site. Contemporary Clin Dent 2016 Jan-March;7(1):3-10
6. Gregory M Horning et al J Periodontics and Restorative Dent 2008 Aug
7. Michael K McGuire et al. J Periodontology 2022 March
8. Pallavi Thakare et al J Indian Society Periodontology 2015 Sept-Oct
9. Yoon Jeong Kim et al Enhancing Soft-Tissue Around Dental Implants: The Importance of Keratinized Mucosa Width and Mucosal Thickness Compendium July /Aug 2025 316 – 320
10. Anthony L Neely et al Management of Retrograde Peri-Implantitis Using Guided Bone Regeneration Compendium July / Aug 2025 322-326
11. Dental Clinics of North America Volume, 13, Issue 1, January 1969, Pages 133 – 148.
12. Michael K McGuire et al, J Periodontal, 2012 Nov.
13. G Cordioli et al, J Periodontal, 2001 Nov.
Figures and Images
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LAURENCE JAY LEVINE, DDS
