Soft-Tissue Root Coverage: Clinical Rationale and Case Report

Although tissue grafting for root coverage is not a new concept,1  periodontal plastic surgery and aesthetic soft-tissue grafting for root coverage have not always been a mainstay of periodontics.  Periodontal plastic surgery, where the result is both functional and aesthetic, evolved from the concept of mucogingival surgery.  To better understand this evolution, it is helpful to appreciate some of the history of periodontics. 

During the 1940s and 1950s, the debate in the field of periodontics concerned the “conservative” nonsurgical treatment of periodontitis versus the “radical” surgical form of treatment.  At that time, surgical therapy for periodontitis was primarily resective in nature.2  As a result of this type of surgical therapy, attached gingiva was removed, and many practitioners then became familiar with the disadvantages of alveolar mucosa adjacent to teeth. The concept of mucogingival surgery developed as a means to treat these problem and was defined in 1955 as those procedures dealing with (a) abnormal frenum attachment; (b) shallow vestibule and vestibular deepening to enhance oral hygiene; and (c) the problems associated with a deficient zone of attached gingiva.3 

In 1956, Grupe and Warren4 described a “sliding flap operation” to repair gingival defects.  This procedure is considered by many to be the first periodontal plastic surgical procedure.  During the early 1960s, it was recognized that this technique had limitations with respect to appropriate donor site availability and postoperative donor site recession.  These limitations led to several technique modifications and development of other pedicle graft techniques.5-8 

As clinicians became familiar with the limitations of pedicle graft procedures, published reports on gingival free grafting began to appear in the American literature in the 1960s.9-12  It was not until Sullivan and Atkins published their classic trilogy of articles on indications, techniques, and wound healing that autogenous free grafting became popular.13-15  During the decade of the 1970s, clinicians recognized the limitations of free grafting for root coverage.  The emphasis in autogenous free-grafting surgery then became prevention of recession by augmentation and establishment of an “adequate” zone of attached gingiva.16-18  In the early 1980s, free-grafting techniques were adapted to increase predictability for root coverage.19,20  The free grafts used in these procedures were still epithelialized but were thicker than those used for gingival augmentation.  These techniques were successful in covering denuded roots but tended to have a patch-like, keloid appearance.

Improved outcomes of root coverage procedures with respect to gingival color and texture were achieved with free connective tissue autografts in the mid-1980s.  During this time, a number of articles demonstrated the efficacy of these techniques for the predictable treatment of exposed root surfaces.21-24 The use of connective tissue from beneath the palatal masticatory mucosa was described by Langer and Langer in 1985.  The “subepithelial connective tissue graft” technique uses a split-thickness flap to harvest transplantable connective tissue without leaving a large denuded palatal donor wound.  This technique “was designed specifically for multiple contiguous teeth with recession, which are frequently found in the maxilla, and where root coverage seems to be the most difficult to obtain.  The technique is adapted from the subepithelial connective tissue graft that is used to correct edentulous ridge concavities25,26  and it combines elements of the pedicle and the free gingival graft.”27  It is noteworthy that in this technique article, the authors reported that “they made no attempt to completely cover the graft because an excessive pull on the vestibular fold would be created.”

In the opinion of the author, when these techniques are compared to epithelialized free grafts they have the following advantages:  (1)  a less-invasive palatal donor wound that leads to faster primary intention healing27;  (2)  a simpler technique;  (3) more predictable root coverage;  and (4)  better gingival blending and better aesthetic outcome. 

In addition, during this time, the system for classifying gingival recession was modified, as reported by Miller.28   Instead of simply describing the recession as wide, narrow, deep, or shallow, Miller also categorized the adjacent bone and soft tissue height and the prognosis for root coverage. The categories are as follows:

Class I: Marginal tissue recession that does not extend to the mucogingival junction. There is no loss of periodontal tissue in the interdental area. Complete root coverage can be anticipated.

Class II: Marginal tissue recession that extends to or beyond the mucogingival junction. There is no loss of periodontal tissue in the interdental area. Complete root coverage can be anticipated.

Class III: Marginal tissue recession that extends to or beyond the mucogingival junction. There is loss of periodontal tissue in the interdental area or malpositioning of the teeth. Partial root coverage can be anticipated.

Class IV: Marginal tissue recession that extends to or beyond the mucogingival junction. There is severe loss of periodontal tissue in the interdental area or severe malpositioning of the teeth. Root coverage cannot be anticipated. 

Another area of basic scientific and clinical research that has changed periodontics has been the improved understanding of the role of growth factors in cellular development, wound repair, and tissue regeneration. In 1996, a porcine-derived amelogenin growth factor received Food and Drug Administration approval and became commercially available in the United States as the product Emdogain. During root formation, amelogenins and other growth factors are produced by mesenchymal cells of the dental follicle, which are influenced by the remnants of Hertwig's Epithelial Root Sheath (HERS). The mechanism proposed in the mid-1970s was that cementoblast differentiation is stimulated by enamel matrix proteins associated with HERS.29,30 The efficacy of amelogenin growth factor for enhancing periodontal regeneration has been reported in numerous articles.31-37

This article will present a case where a Miller class I gingival recession adjacent to a buccal class V composite resin restoration was successfully treated. The treatment plan employed a supraperiosteal envelope graft (SEG).21 The SEG technique has also been modified and adapted for multiple site applications.38,39 The case presented in this article also used an amelogenin growth factor to enhance wound healing and root coverage.

CASE REPORT

Figure 1. Facial view of gingival recession on tooth No. 12. The patient complained of root sensitivity in addition to the unaesthetic appearance when smiling. Note the facial class V composite resin restoration.

A 49-year-old female presented with a medical history of well-controlled asthma, hypothyroidism, and hypertension.  During her pre-examination interview, the patient expressed concern about thermal root sensitivity present on tooth No. 12. Additionally, she wanted to improve what she perceived to be the unsightly appearance of the tooth when smiling. Her clinical examination revealed a healthy periodontium (probing depths 2 to 3 mm without bleeding).  Tooth No. 12 exhibited 3 mm of recession, 3 mm of attached gingiva, a 2-mm midfacial probing depth, and a class V composite resin restoration. Lastly, the exposed root surface was very sensitive to tactile stimulation (Figure 1).

Treatment Plan

Due to the presence of a Miller class I gingival recession, root sensitivity, and a desire to correct the asymmetry present in her smile, a supraperiosteal envelope free connective tissue autograft was recommended. This technique has 4 advantages: (1) the supraperiosteal envelope has no vertical releasing incisions (this is of importance in regard to aesthetics); (2) the bilaminar blood flow (deep and superficial to the graft) during healing will promote ideal healing to allow for root coverage; (3) this technique yields the most new attached gingiva following treatment40; and (4) the thickening of the attached gingiva over a prominent root surface that results from this procedure greatly reduces the likelihood of a recurrence of gingival recession, provided that behavioral etiologic factors have been modified.

The root sensitivity present on tooth No. 12 suggested that attachment of the grafted tissue to the exposed root surface was needed to successfully treat her chief complaint. Because of this  requirement, the off-label use of an amelogenin growth factor was recommended to and accepted by the patient.  The other treatment options presented to and rejected by the patient were (1) supraperiosteal envelope graft without amelogenin growth factor; (2) subpedicle connective tissue graft with or without amelogenin growth factor; (3) coronally positioned flap with a resorbable barrier; (4) additional attempts at in-office root desensitization; and (5) no treatment.

Preparation of the Exposed Root Surface

Figure 2. Facial view following mechanical root debridement. Figure 3. PrefGel neutral pH buffered 24% ethylenediaminetetraacetic acid (EDTA) applied to root surface.

The exposed root surface was decontaminated by scaling and root planing. This was accomplished with hand and rotary instrumentation. Several different hand instruments may be used to accomplish this task. In this case, a Kirkland 13K-KL hoe was used. Some of the other common instruments used for this task include hand curettes or a Rhodes chisel. The root surface was further prepared using rotary instruments (Figure 2). Here, a 12- fluted Neumeyer finishing bur was used. The root surface was then chemically biomodified. Both saturated citric acid and tetracycline hydrochloride have been used for this purpose.41,42 In this case, the smear layer that resulted from instrumentation was removed and the root surface was decontaminated using a neutral pH 24% ethylenediaminetetraacetic acid (EDTA) gel (Pref Gel, Biora, Figure 3). This has been shown to remove smear layer while not damaging the pleuripotential cells of the periodontal membrane.43-48

Supraperiosteal Envelope and Connective Tissue Free Graft

Figure 4. A split-thickness supraperiosteal envelope flap is created over the facial surface of tooth No. 12.

The supraperiosteal envelope was created (Figure 4) using a sulcular incision at the facial gingival margin. This incision penetrated to the buccal osseous crest. A sharp dissection of the facial gingiva then proceeded in an apical direction until an "envelope" or "pouch" had been created. During the dissection, the presence of an osseous dehiscence on the buccal surface was confirmed. The dissection extended approximately 4 mm beyond the dehiscence. This technique, when used for a single tooth, necessitates a dissection of the adjacent interdental papillae. This papillary dissection should approach the line angles of the approximal teeth. This dissection does not sever and elevate the papillae as would be seen with traditional flap reflection. Without this aggressive undermining dissection of the interdental papillae, the coronal positioning of the connective tissue graft would be limited and compressive forces on the graft would be created. This would result in corrugation of the transplanted connective tissue and would limit the amount of root coverage.

Palatal Subepithelial Connective Tissue

Figure 5. Free connective tissue autograft after harvesting from palate.

After preparation of the recipient site, measurements were made to determine the size of the graft to be harvested from the palate. The harvested connective tissue must cover the denuded root and extend under the dissected gingiva. This recession was 3 mm in a supero-inferior direction and 4 mm in a mesio-distal direction. Connective tissue was harvested from the palate adjacent to teeth Nos. 12 and 13 using a 1-incision split-thickness flap.49,50  During this sharp dissection, it is important to be aware of blade angulation and penetration due to the relative proximity of the greater palatine vessels.51  The connective tissue graft harvested was approximately 10 x 6 x 2 mm in dimension (Figure 5). The palate wound was then closed using 5-0 resorbable sutures. The 1-incision entry wound greatly facilitated primary closure and rapid healing by primary intention.

Amelogenin Application and Graft Placement

Figure 6. Emdogain enamel matrix derivative (EMD) applied with syringe and blunt cannula to root surface. Figure 7. Connective tissue autograft positioned externally over the envelope flap to check the size prior to positioning within the flap.
Figure 8. Connective tissue autograft placed into distal aspect of supraperiosteal envelope flap. The autograft was positioned completely into the envelope prior to suturing.

Prior to placement of the free connective tissue autograft within the supraperiosteal envelope, the root surface was treated with the amelogenin growth factor (Figure 6). This amelogenin growth factor is a porcine-derived enamel matrix derivative (EMD) marketed as a ready-to-use product (Emdogain, Biora) which is currently available as a viscous, syringeable gel. The EMD growth factor has been shown to enhance cellular activity during healing52 and improve periodontal regeneration.31-37 Once the Emdogain was applied and the proteins were allowed to bind to the root surface for 2 minutes, the connective tissue graft was positioned into the supraperiosteal envelope with its greatest dimension oriented in the mesio-distal direction (Figures 7 and 8). Because the facial flap is not fully mobilized and no vertical incisions are used, the supraperiosteal envelope graft technique leaves part of the connective tissue graft over the denuded root surface uncovered by gingiva. Wound closure and stabilization is completed with 5-0 and 6-0 resorbable sutures. Routine postsurgical home care was reviewed with the patient, as follows:  food, day 1—cold liquids; days 2 through 7—no hard/sharp/or scratchy food items, all other menu selections are fine; hygiene—brush/floss all other areas, treatment area to be cleaned using chlorhexidine with a cotton swab twice per day for 2 months.

HEALING

Figure 9. Facial view of tooth No. 12 at 14-day
follow-up appointment.
Figure 10. Palatal view of donor area at 14-day follow-up appointment.

The 14-day follow-up period was uneventful and resulted in rapid healing. At this time, the palatal donor wound, the connective tissue autograft, and the recipient wound were reepithelialized and hyperemic (Figures 9 and 10). This is desirable at this stage of healing. This hyperemia and swelling of the transplanted tissue indicates that it has revascularized. Further, the patient was very comfortable. This is in contrast to the healing associated with the epithelialized free soft tissue autograft (more commonly known as a free gingival graft).

Figure 11. Facial view of tooth No. 12 at 30-day follow-up appointment. Figure 12. Facial view of tooth No. 12 at recall appointment 2 years after treatment.

The 30-day healing revealed complete root coverage and an increase in the zone of attached gingiva (Figure 11). An increase in the gingival thickness was also achieved. This thickening of the attached gingiva over the prominent root of tooth No. 12 may prevent gingival recession from recurring. The patient now resumed standard atraumatic oral hygiene practices in the treated area. The 2-year follow-up demonstrated the effectiveness of the therapy (Figure 12).

CONCLUSION

Periodontal plastic surgery evolved from the concept of mucogingival surgery.  Mucogingival surgery strives to restore the periodontium to a healthy functional state. Periodontal plastic surgery strives to restore the periodontium to a healthy, functional, and aesthetic state.  The ideal outcome is when there is no discernable evidence that treatment has occurred.  Periodontal plastic surgery encompasses more than soft-tissue grafting for root coverage.  Other examples of the discipline include (1) aesthetic crown lengthening53; (2)  surgical exposure of teeth for orthodontic movement54; and (3) preprosthetic ridge augmentation.55

This article has presented a case where a Miller class I gingival recession approximating  a preexisting buccal class V composite resin restoration was successfully treated. This case was treated using a free connective tissue autograft, the supraperiosteal envelope flap technique, and a porcine-derived amelogenin growth factor. The treatment outcome resulted in resolution of the patient's root sensitivity, complete root coverage, a thickening of the attached gingiva over the prominent root surface, and an excellent aesthetic result.


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G. Richard Young, DDS, graduated from the Indiana University School of Dentistry. After completing an advanced education in general dentistry at the Irwin Army Hospital in Fort Riley, Kan, he practiced general dentistry for 5 years. He completed his residency in periodontology at the University of Michigan. He maintains a private practice limited to periodontics in Des Moines, Iowa. His practice has an emphasis in aesthetic periodontal regeneration, cosmetic periodontal reconstruction, and dental implants. Dr. Young can be reached by phone or fax at (515)224-1771 and by e-mail at This e-mail address is being protected from spambots. You need JavaScript enabled to view it .