Evaluation of a bioabsorbable collagen membrane in the treatment of localized gingival recession – a case series”

INTRODUCTION

Gingival recession or marginal soft tissue recession is the location of the gingival margin apical to the cementoenamel junction.¹ Although marginal tissue recession seldom results in tooth loss, it is associated with root hypersensitivity, frenal involvement, marginal tissue irritation, esthetic concerns, and a predilection to root caries.² Recession of gingival tissues from the root surfaces of teeth has long been a concern of many patients who feel that the “long-in-the-tooth” look is universally accepted as a sign of ageing and tooth loss.³ Hence, intense desire for esthetics could prompt the patient to seek treatment for gingival recession.

Numerous surgical techniques, such as pedicle flaps, free gingival grafts, coronally repositioned flaps and connective tissue grafts have been developed in the treatment of gingival recession. Each of these has disadvantages. Pedicle flaps which require a neighbor donor site with adequate gingival height and thickness for rotation of the flap, may lead to development of gingival recession and/or loss of gingival height at the donor area.⁴ Studies using epithelialized free gingival grafts for the treatment of gingival recession demonstrated a wide range of success, varying from 11% to 87% with respect to root coverage.⁵ Results of FGG procedures are associated with an unsatisfactory final aesthetic appearance and discomfort during secondary intention healing of the donor site. The use of subepithelial connective tissue grafts has been highly predictable in gingival recession therapy with respect to a high percentage of root coverage, better healing and less postoperative discomfort at the donor site when compared to free gingival grafts.⁶ However, this procedure requires a second surgical site for harvesting the graft, which could be associated with post surgical bleeding and patient discomfort during the healing phase.⁷

More recently, guided tissue regeneration (GTR) has emerged as a predictable alternative to subepithelial connective tissue grafts for the treatment of gingival recession using either nonabsorbable or absorbable membranes. However, the need for a second surgical procedure for the removal of non-absorbable membrane and its associated complications has made use of absorbable barrier membranes more favourable. Of these absorbable membranes, collagen membranes are being widely used.⁸ Hence, a bio-absorbable collagen membrane was used for the treatment of localized gingival recession in the following case series.

Three systemically healthy patients, showing localized Miller’s class I or class II gingival recession,⁹ from among the patients referred to department of Periodontics, received GTR-based gingival recession therapy. Patients were explained the procedure in detail and their written consent for the same was obtained.

Pre-surgical treatment

The patients were educated and motivated with emphasis on proper oral hygiene maintenance. All the patients underwent the initial phase of treatment which consisted of thorough scaling and root planning. GTR based gingival recession therapy was performed on the patients after assessing their ability to maintain good oral hygiene.

Case 1

A 21 year-old male patient reported with sensitivity for cold and sweet food and beverages, in relation to upper right first premolar. On examination, the upper right first premolar showed Miller’s class I gingival recession of about 5 mm. Inadequate width of attached gingiva and a 2mm probing depth were observed and the patient had noticed progressive recession since 7 months (Figure 1).

Surgical Technique

The surgical area was prepared with adequate anesthesia using 2% Lignocaine HCl containing 1:80,000 adrenaline. A trapezoidal flap was designed using 3 different types of incisions. Primary incisions were made in mesial and distal directions from the cementoenamel junction up to 1 mm of the proximal line angle of the adjacent teeth, leaving the interdental papilla intact. Second, a sulcular incision was made connecting the primary incisions, preserving all the existing radicular gingiva. Third, two apically diverging vertical incisions are made starting at the end of each of the primary incisions and extending apically into the alveolar. An initial blunt followed by a sharp dissection with a No. 15 scalpel blade was made to raise a combined full-partial thickness flap (Figure 2). The flap was extended well beyond the mucobuccal fold so that it exhibited no tension when pulled coronally beyond the cementoenamel junction. The root was thoroughly planed and any convexities of the root were reduced. The intact papillae mesial and distal to the recession were deepithelized.

The sterile collagen membrane was trimmed and contoured as needed to cover the recipient site, covering at least 2 mm of the bone all around (Figure 3). Firm pressure was applied over the collagen membrane with sterile moist gauze for 5 minutes to adapt and adhere to the recipient site. The membrane was secured in position with 5-0 vicryl sutures (Figure 4). The flap was coronally repositioned over the collagen membrane to completely cover it, and secured in position with sling sutures (Figure 5). Post-surgical instructions were given and patient was recalled for suture removal after 1 week. A follow up at the end of 6 months, revealed 100% root coverage with excellent color match (Figure 6). The percentage of root coverage was calculated according to the following formula.¹⁰

Root coverage = Recession depth (preoperative – postoperative) / Recession depth preoperatively X 100

Case 2

A 23 year-old female patient reported with a complaint of long clinical crown in relation to upper right canine. On examination, Miller’s class I gingival recession of about 4 mm and 2 mm width of keratinized gingiva was recorded on the upper right canine. Initial incision (Figure 7) was given, and a similar procedure as described under case 1 was performed. At a follow up of 6 months, 100% root coverage was noted (Figure 8), with an increase of width of keratinized gingiva to 4 mm.

Case 3

A 28 year-old male patient reported with long looking tooth and sensitivity in relation to upper left first premolar. On examination, the upper left first premolar showed Miller’s class II gingival recession of about 4 mm (Figure 9). GTR based gingival recession therapy was carried out as described for case 1. 100% root coverage with 2 mm increase of width of keratinized gingiva was observed at follow up after 6 months (Figure 10).

DISCUSSION

Gingival recession is an intriguing and complex phenomenon. Recession frequently disturbs patients because of sensitivity and esthetics. Hence, gingival recession coverage therapy forms an important part of periodontal therapy.

Many surgical techniques have been introduced to treat gingival recession, including those involving autogenous tissue grafting, various flap designs, orthodontics, and guided tissue regeneration.¹¹ The use of GTR has been suggested for treatment of recession. Tinti and Vincenzi first reported a case where GTR using an expanded polytetrafluoroethylene (ePTFE) membrane was used to treat recession defects.¹²Cortellini, Clauser, and Pini Prato also demonstrated, histologically, that the root coverage obtained with an ePTFE membrane included new connective tissue attachment as well as new bone formation.¹³

Collagen is a natural protein and an integral part of mammalian tissues. There is a similarity between collagen in human skin and certain animal tissues. The rationale for selecting collagen were: Collagen is the major extracellular macromolecule of the periodontal connective tissue and is physiologically metabolized by these tissues, it has been shown to be chemotactic for fibroblasts, acts as a barrier for migrating gingival epithelial cells, serves as a fibrillar scaffold for early vascular and tissue ingrowth, facilitates early wound stabilization and maturation, possess hemostatic properties through its ability to aggregate platelets and is very weakly immunogenic, hence biocompatible.^7,14

The collagen membrane used in this case series was indigenously developed by Central Leather Research Institute, Chennai, which was type I collagen prepared from purified soluble bovine Achilles tendon (not yet available commercially).¹⁵ The collagen membrane was cross-linked by glutaraldehyde and sterilized by ethylene oxide gas and had a resorption time of 3-4 weeks. Crosslinking enhances the stability of collagen thereby delaying resorption time. The resorption of the collagen membrane falls well within the time specified by a study which has reported that during GTR procedures, bone and/or periodontal ligament cell migration reach their peaks in 2 to 7 days after surgery, with a decrease in mitotic activity to almost normal levels by the end of 3-4 weeks.¹⁶ Shieh et al reported 51.6% root coverage with GTR based gingival recession therapy using collagen membrane.10 Zahedi et al reported mean root coverage of 82.2% after 2 years using collagen membrane.¹⁷ Comparing connective tissue graft and GTR for root coverage, other studies have reported thus, Zucchelli et al¹⁸ GTR=85.7%; Trombelli et al¹⁹ GTR=48%; Harris et al²⁰ GTR=75.1%. Rosetti EP et al⁶ reported root coverage of 84.2% for collagen based GTR techniques.

The outcome of any root coverage procedure is influenced by many factors, such as the oral hygiene maintenance, pre-treatment defect size and location. In addition, the root coverage being a very sensitive or technically demanding procedure, the surgical experience of the clinician is another very important factor which can affect the final treatment outcome. The cause of localized recession in the present case series seemed to be that of due to plaque induced periodontal disease. The success of the treatment procedure could be attributed to patients showing excellent oral hygiene maintenance following the procedure.

CONCLUSION

The resorbable collagen membrane used for GTR based root coverage therapy in the present case series, was well tolerated by the patients and effectively achieved structurally and functionally stable root coverage. Improvement in aesthetics and reduction of tooth sensitivity were the successful outcomes. It could be concluded that collagen membrane could be used to achieve predictable root coverage.