The subepithelial connective-tissue graft has become one of the most researched procedures used to achieve gingival augmentation. Multiple indications such as root coverage, pontic site development, implant site regeneration, and increasing the width of attached gingiva have established the connective-tissue graft as the gold standard technique in mucogingival surgery.¹ The transplantation of autologous connective tissue, harvested primarily from the palate and positioned onto the deficient site, has been published since the early 1980s with repeated success and predictability. For the purpose of covering denuded roots, multiple surgical techniques have shown variable degrees of success. From these modalities, we can site the following: the free gingival autograft²; the coronally positioned flap³; pedicle flaps—the lateral positioned flap⁴, the double papillae graft^5,6; the subepithelial connective-tissue graft⁷; the application of allograft material (acellular dermal matrix)⁸; and guided tissue regeneration with the application of barrier membranes⁹ (resorbable or nonresorbable), biomimetic agents (Emdogain [Straumann, Andover, MA 01810; www.straumann.com ]), and growth factors (platelet-derived growth factor).^10,11

Since the technique described by Langer and Langer in 1985,⁷ multiple variations have been reported with the same basic biologic and surgical concepts maintained.⁹ This article will describe the surgical steps used to perform the subepithelial connective-tissue graft with special emphasis on the latest variation, the tunnel autologous soft-tissue graft, for the treatment of multiple Class I or II buccal gingival recessions.

Basic Surgical Technique

Incision Design

The initial sulcular incision is extended beyond the recession areas with a #15, 15C, or a microsurgical scalpel to develop the recipient site. Partial-thickness flap dissection is achieved by extending the initial incision apically. This will assure a bleeding periosteal bed. The recipient site should be wide enough to ensure optimal lateral vascularization. Vertical releasing incisions and papillary elevation will allow for flap relaxation and access in all directions to advance the flap coronally.

Root-Surface Preparation

A root surface free of plaque, deposits, or any restorative material represents an optimal biological surface onto which the autograft will heal and lead to reattachment, repair, or regeneration. Healing with a connective attachment was shown in human histological specimens.¹²

Mechanical root planing is done to remove cementum and soft dentin and to achieve a smooth surface without accretions. This is usually performed with hand instrumentation, combined with ultrasonic and rotary finishing burs in case of heavy surface irregularities.¹³

Chemical root biomodifications. Acid conditioning (tetracycline or citric acid, edetic acid) to remove the smear layer and to expose wider dentinal tubules has shown beneficial effects in animal studies.¹⁴ Human studies still show controversial results when applying root biomodification compared with no root conditioning. Histologic reattachment to the previously exposed root surfaces seems to be the same with or without chemical root surface preparation.¹⁵ It is the authors' view that surface detoxification remains the stronger rationale for surface conditioning before soft-tissue grafting procedures.

Graft Harvesting

The location of choice to harvest the autologous graft is commonly the palatal aspect of the recipient area. The incision design has been modified over time from a window or trap door^7,16 to the single-incision harvesting technique.¹⁷ The thickness of the available palatal mucosa plays an important role as well.

Studies have shown that the premolar areas exhibit thicker palatal tissue but with increased fat content.^17,18 The palatal tissue in the maxillary molar area will often provide a more fibrotic tissue quality yet thinner with diminished apicocoronal dimension because of the proximity of the palatine artery.¹⁸ The graft size has been shown to influence the treatment outcome. Larger grafts seem to maintain adequate interstitial vascularity and less resorption during healing.²

Figure 1—Class I recession with minimal attached gingiva.

Figure 2—Incision with the papillae preserved.

Figure 3—The graft in firm contact with the underlying periosteal bed.

Figure 4—Healing at the time of suture removal, 7 days after surgery.

Figure 5—Healing 6 weeks after surgery.

Graft Application and Wound Closure

A variety of techniques are available to allow secure graft positioning and suturing. A key factor is wound stability and lack of graft movement. The stability of the initial fibrin clot under the graft is crucial in the early wound healing, leading to graft incorporation and revascularization. Adequate size of the periosteal bed and the lack of muscle tension, through excision of all muscle fiber remnants, provides an optimal vascular site to receive the graft. Interrupted interproximal suturing secures the grafts over the exposed root, usually at or slightly coronal to the cementoenamel junction. Resorbable (gut or vicryl) or nonresorbable (silk or Gore-tex [Gore-Tex, Elkton, MD 21921; www.gore-tex.com ]) suture material has been used. Single, continuous, or internal matrices also have been described in the literature.

Flap Positioning

The original flap could be repositioned to its previous position leaving a portion of the graft exposed.⁷ Some studies suggest a beneficial aspect of intentional graft exposure (maintain vestibular height with the possibility of surface keratinization over the graft area).

Coronal flap positioning to completely cover the connective-tissue graft is usually performed in conjunction with apical periosteal incisions. This presents the advantage of additional blood supply to the graft and the ease of advancing the flap coronally. There is also increased predictability in more demanding coverage procedures.

Figure 6—Multiple adjacent Class I recession.

Figure 7—Intracrevicular incision extended beyond the mucogingival junction.

Figure 8—Graft application.

Figure 9—Healing 12 weeks after surgery.

The Tunnel Technique

As previously stated, mucogingival procedures are used in a multitude of clinical situations, all emanating from the same, previously described basic biologic and surgical concepts. A newly described treatment modality using the autologous graft is the tunnel graft technique.¹⁹ The basic idea is to preserve the integrity of the interdental papillae, inserting the graft through a tunnel preparation mesiodistally along the affected area. The advantages of such site preparation are less tissue reflection, less scarring, increased vascularity, and better graft adaptation and security.

Incision

A pouch preparation is performed with a crevicular incision extended interproximally and apically with a sharp partial thickness dissection. The base of the papillae is carefully undermined using a microblade or a sharp Orban knife. Superficial flap relaxation will be achieved through significant proximal extension of the incision.

Root Preparation

Root-surface preparation will follow. Mechanical or biochemical root preparation is similar to the previously described methods. Care should be taken to ensure apical extension. Exposure and access to the periodontal ligament and supracrestal attachment will help to ensure optimal graft reattachment. Figures 1 and 2 illustrate the incisions designed for Class I multiple recessions in the mandibular anterior area.

Graft Application

The graft is inserted into the recipient pouch directly from the sulcular space. The use of a suture attached to the edge of the graft and passed along the base of the papillae to help slide the graft in 1 direction along the entire recipient site allows minimal flap tension and a decreased likelihood of papillary separation. Attention should be given to the firm application of the connective-tissue graft to induce early fibrin reattachment and a thin film of clot interposed between the graft and the periosteum (Figure 3). The remaining blood clot and continuous bleeding will be associated with ecchymosis and significant postoperative swelling (Figures 4 and 5).

Suturing

Internal interrupted suturing is recommended. Starting from the palatal (lingual) aspect of the interproximal space, the suture needle exits the buccal interproximal space and engages the grafts at the corresponding line angle. The suture will terminate again at the lingual or palatal aspect, assuring firm graft pressure against the exposed root surface. Figures 6 through 9 illustrate the treatment of Class I miller with the tunnel technique.

Conclusion

Today, we have a multitude of modalities to treat gingival deformities. The connective-tissue graft is the gold standard, especially when treating multiple adjacent recessions. Applying the tunnel technique, in conjunction with the autologous connective tissue graft, offers the advantage of increased graft stability and revascularization. In addition, because of minimal changes to the mucogingival junction and preservation of papillary integrity, this technique enhances the esthetics.

References

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2. Sullivan HC, Atkins JH. Free autogenous gingival grafts. 3. Utilization of grafts in the treatment of gingival recession. Periodontics. 1968;6:152-160.
3. Allen EP, Miller PD. Coronal positioning of existing gingiva: short term results in the treatment of shallow marginal tissue recession. J Periodontol. 1989;60:316-319.
4. Grupe HE, Warren RF Jr. Repair of gingival defects by a sliding flap operation. J Periodontol. 1956;27:92-95.
5. Harris RJ. The connective tissue with partial thickness double pedicle graft: the results of 100 consecutively-treated defects. J Periodontol. 1994;65:448-461.
6. Cohen DW, Ross SE. The double papillae repositioned flap in periodontal therapy. J Periodontol. 1968;39:65-70.
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8. Harris RJ. A comparative study of root coverage obtained with an acellular dermal matrix versus a connective tissue graft: results of 107 recession defects in 50 consecutively treated patients. Int J Periodontics Restorative Dent. 2000; 20:51-59.
9. Pini Prato G, Clauser C, Cortellini P, et al. Guided tissue regeneration versus mucogingival surgery in the treatment of human buccal recessions. A 4-year follow-up study. J Periodontol. 1996;67:1216-1223.
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14. Wikesjö UM, Claffey N, Christersson LA, et al. Repair of periodontal furcation defects in beagle dogs following reconstructive surgery including root surface demineralization with tetracycline hydrochloride and topical fibronectin application. J Clin Periodontol. 1988;15:73-80.
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18. Reiser GM, Bruno JF, Mahan PE, et al. The subepithelial connective tissue graft palatal donor site: anatomic considerations for surgeons. Int J Periodontics Restorative Dent. 1996; 16:130-137.
19. Tozum TF, Dini FM. Treatment of adjacent gingival recessions with subepithelial connective tissue grafts and the modified tunnel technique. Quintessence Int. 2003;34:7-113.