Aesthetic root coverage with acellular dermal matrix allograft: a shield for gingival recession

Abstract

Awareness about root coverage is increasing in day-to-day clinical practice. Patients are more motivated and concerned about aesthetics nowadays along with the issues of sensitivity of teeth. The conventional flap designs and techniques including lateral sliding flaps, coronally advanced flap, subepithelial connective tissue grafts and free gingival grafts are being adopted for root coverage. The newer material including resorbable and non-resorbable guided tissue regenerative membranes, amniotic membrane, platelet-rich fibrin membrane, enamel matrix derivative protein, xenogenic collagen matrix graft along with the soft tissue substitute like acellular dermal matrix allograft are also being used for recession coverage. The present case report describes a case of 22-year-old female patient with the chief complaint of denudation of gums exposing the root surface over the mandibular left central incisor. The soft tissue substitute acellular dermal matrix allograft was used for root coverage as the patient was not willing to procure an autogenous palatal graft. The results were satisfactory with complete root coverage.

Background

The prevalence and extent of recession are increasing with age.¹ Along with that the demand for aesthetic root coverage is increasing enormously. This undeniably is increasing need of newer root coverage material and techniques to fulfil the patient-centred aesthetic demand. Currently, root coverage procedures adopted in periodontics include the pedicle grafts which include both the lateral sliding flaps and double papillae with or without connective tissue grafts, the free gingival autogenous grafts, connective tissue grafts (CTG), coronally positioned flaps (CPF) alone, CPF preceded by a free gingival graft and CPF with a simultaneous CTG. All the above techniques have varying degrees of predictability.²

Acellular dermal matrix allograft was originally used to cover burn wounds, revision of depressed scars and rhinoplasty along with facial defect coverages.^{3 4} It is now being used in periodontal plastic procedures and alveolar ridge deformities. This exogenous tissue is considered advantageous because it eliminates the need to obtain a palatal connective tissue graft from the patient, resulting in less patient morbidity.

When the human donor graft was processed the dermis gets devoid of all the cells, and this helps in achieving a matrix made of connective tissue which is dominantly rich in collagen type I fibres. Harris reported the use of acellular dermal matrix clinically and histologically beneficial and at par with the gold standard connective tissue grafts in colour matching. The acellular dermal matrix allograft consistently got integrated with the recipient bed and obtained structural integrity by revascularisation from the remaining vascular bed channels. It is processed by removing the epithelium from the donor tissue, but the basement membrane is kept safely to promote faster re-epithelialisation. Then, denudation of cells is done from the remaining tissue by a series of detergents which eliminates the antigenic response in the patients. The tissue procured after chemical treatment is then freeze-dried and packaged for immediate use. The graft material consists of a connective tissue surface that readily absorbs blood and a basement membrane surface that does not allow for blood absorption.⁵

Case description

A 23-year-old female patient having chief complaint of sensitivity of teeth reported to Department of Periodontology. The diagnosis of gingivitis and Miller’s class II gingival recession on tooth #31 was made. Clinically, 7 mm of clinical attachment loss, 6 mm of recession and 1 mm of pocket depth was present on probing with William’s graduated probe (figure 1). The patient had a history of trauma with the nail on the gingiva of the tooth. The oral prophylaxis was done which included scaling, for removing plaque and calculus present in the teeth. The patient was recalled after taking informed consent for surgery after 15 days. The complete blood investigations were done and found to be in a normal range.

Figure 1.

Preoperative buccal view of tooth #31 depicting 6 mm of Miller’s class II recession.

Recipient bed preparation

The patient was prepared and local anaesthesia was given. The bed was prepared by giving intrasulcular incisions throughout the crevice along with tooth #31. After intrasulcular incisions, two horizontal incisions were given perpendicular to the tooth at the level of cementoenamel junctions of length 3 mm (figure 2). The main aim of this horizontal incision was to preserve the base of papilla on both sides, and the intention was to preserve the blood supply for the graft from the coronal area. At the end of these horizontal incisions, two vertical incisions were given extending beyond the mucogingival junction. The two oblique incisions were made to form a trapezoid which was broader at the base and narrower coronally. After the incisions, the split-thickness flap was reflected and the muscle attachments were eliminated to propagate the coronal advancement of the flap easily. The root surfaces were scaled to remove debris, plaque and calculus, along with that they were treated with tetracycline (100 mg/mL for 4 min) for root conditioning. The papillae were then de-epithelialised to ensure a good vascular and connective tissue bed.

Figure 2.

Preoperative buccal view depicting marking of incision lines for recipient bed preparation.

Alloderm placement

The acellular dermal matrix allograft (AlloDerm RTM membrane, manufactured by Biohorizons) was rehydrated for at least 10 min in a tetracycline solution (250 mg tetracycline per 50 mL of sterile saline) according to the manufacturer’s instructions. The acellular dermal matrix allograft was cut in proper shape and size as that of the recipient bed. The graft was then placed and sutured to fit the area. The graft was adjusted to completely cover the defect and was positioned 1–2 mm above the cemento- enamel junction (CEJ), while the inferior and lateral borders of the graft were extended at least 3.0 mm beyond the osseous defect margins (figure 3).

Figure 3.

Recipient bed prepared and acellular dermal matrix allograft membrane sized and shaped with that of bed and secured with vicryl sutures.

The coronal border of the graft material was sutured at the interproximal papillae to facilitate adequate blood flow between the papillae and the flap. The graft was placed with the basement membrane side (smooth side) against the root surface and sutured using a sling suture technique with 4–0 vicryl sutures. Following anchoring of the graft material, the flap was coronally repositioned and sutured using a double sling suture technique. The releasing incisions were closed with interrupted sutures placed using 4–0 vicryl sutures (figure 4).

Figure 4.

Coronally advanced flap positioned over the acellular dermal matrix allograft and secured with sutures.

Postoperative protocol

The recommended postoperative protocol included the tablet doxycycline hyclate as 50 mg once a day for 10–14 days as a chemotherapeutic agent to prevent plaque from colonising over the recipient bed and to enhance healing. Aceclofenac 375 mg two times per day for 7 days was used to control inflammation and swelling as well as postoperative pain. Chlorhexidine digluconate 0.12% (CHX) regimen included mouth rinse for 15 days along with that patient was instructed to apply it two times per day with a cotton tip applicator at the site of surgery for 15 days postoperatively for plaque control. The sutures were removed after 15 days.

Recall and outcome

The patient was recalled 1 week postoperatively for check-up as well as 2 weeks postoperatively, the tissue appears firm, resilient and healthy. Complete root coverage was achieved in addition to increasing the thickness of the marginal tissue. At baseline clinical attachment loss was 7 mm while postoperatively at 6 months and 1 year, the clinical attachment loss was zero and healthy gingival sulcus was present. The complete root coverage was attained, the tissue was mature and smooth contour of gingiva was present with adequate colour matching (figures 5 and 6).

Figure 5.

Recall after 6 months depicting complete root coverage.

Figure 6.

Recall after 1 year depicting smooth and thick gingiva covering the recipient bed.

Discussion

Connective tissue grafts have been considered the gold standard for root coverage due to high predictability and colour matching. The predictability ranges from 65% to 98% root coverage.⁶ However, a major drawback of the technique is that it requires an additional donor surgical site which adds on the morbidity and discomfort to the patient as the donor graft is harvested from the palatal mucosa. Also, it increases chair side time for the surgeon. The availability of the acellular dermal matrix allograft for use in mucogingival surgery can minimise or eliminate both of these problems. In the present case report also root coverage along with an adequate thickness of graft was achieved which concludes that acellular dermal matrix allograft is the best substitute for connective tissue grafts in cases where we cannot procure a graft from the donor, as well as the cases of the shallow palatal vault with reduced thickness of palatal tissue.

Graft success with the material is highly dependent on the proper orientation of the material and is technique sensitive. Accordingly, the basement membrane side of the material is placed towards the tooth and bone. Harris⁵ reported the use of acellular dermal matrix clinically and histologically beneficial and at par with connective tissue grafts in colour matching. Connective tissue graft and acellular dermal matrix allograft differ in their healing processes. As connective tissue graft is an autograft, it survives through anastomoses between the graft’s vessels and those of the recipient site. Hence, the flap does not need to completely cover the connective tissue graft. In contrast, the nonvital acellular dermal matrix allograft relies entirely on the migration of host cells and vessels for nutrition and repair. It depends on direct contact between the graft and the flap, and thus, it requires complete coverage with a tensionless flap.

The major disadvantage of acellular dermal matrix allograft is increased chances of failures, prolonged healing time, less long-term stability than the connective tissue grafts and is highly technique sensitive.⁷

Learning points.

• Gingival recession is apical migration of gingiva leading to a sensitivity of teeth and unaesthetic denudation of root surfaces.

• Many root coverage procedures, in which the lateral pedicle grafts, free gingival grafts, connective tissue grafts, subepithelial connective tissue grafts, are used as autografts from the donor in root coverage procedures.

• The regenerative material like enamel matrix derivative protein, xenogenic collagen matrix graft, resorbable or non-resorbable guided tissue regeneration (GTR) membranes, platelet concentrates, etc are also being used along with soft tissue substitutes like acellular dermal matrix allograft and collagen-based matrix.

• Connective tissue graft is considered as a gold standard due to high predictability and colour matching but as it creates a second site so morbidity is increased as well as large-sized defects cannot be covered using autogenous connective tissue grafts.

• The acellular dermal matrix allograft can be used as the best alternative treatment in cases where autogenous donor graft cannot be taken up. The uniqueness of acellular dermal matrix allograft is that it has a basement membrane surface that integrates very well in the oral cavity and can cover root surfaces as large as a full arch in one surgery without creating a donor site.

Ethics statements

Patient consent for publication

Consent obtained directly from patient(s).