The goal of a surgical procedure aimed at treating multiple recessions is to achieve complete root coverage that blends with the surrounding soft-tissue and ensures long-term stability with a sulcus depth no greater than 2 mm. The current, most commonly used techniques for treating multi-tooth recessions can be divided into two groups:
- Multiple coronally advanced split thickness flap1 where the papillae are incised,
- Tunneling where the papillae are not incised.
The tunneling technique for multiple recession coverage derives from the supraperiosteal envelope technique in combination with connective tissue grafts (CTG).2 One of the advantages of this method is preservation of the gingival papilla continuity and creation of a pouch containing a CTG, which is slightly exposed over the recession. However, leaving the graft exposed can jeopardize the aesthetic result.
To overcome this problem, Azzi and Etienne proposed a modification to the supraperiosteal envelope technique.3 This variation consists of a full thickness elevation of the flap that continues beyond the mucogingival line to completely cover the CTG placed underneath.
The modified coronally advanced tunnel technique
During a modified coronally advanced tunnel technique, the exposed root is planed, and contact point composites stops are placed to prevent collapse of suspended sutures in the interproximal spaces.3-5 Initial sulcular incisions and flap separations are made with a microtunnel elevator. Then the mucoperiosteal dissection is extended beyond the mucogingival line and under each papilla to displace the flap together with the papillae in the coronal direction without tension. The muscles fibers or the remaining collagen bundles on the inner part of the flap alveolar mucosa are dissected with extreme care, using a blunt instrument to avoid perforation of the flap and to obtain a passive coronal positioning. After flap preparation, a CTG or a substitute can be placed underneath.
Clinicians still consider multiple recession defects a challenge, as they represent a complicated clinical situation. (Fig. 1, Fig. 2) Systematic reviews evaluating the predictability of various surgical techniques for multiple recessions indicate that the multiple coronally advanced split thickness flap with and without soft-tissue grafting and the modified coronally advanced tunnel technique using soft-tissue grafting are the most predictable ways to obtain complete root coverage in Miller Class I, II and III multiple recessions.6-9 Despite the predictability of these surgical techniques, not all of them are efficacious for class III multiple recessions.
A randomized controlled clinical study by Aroca et al. evaluated whether the addition of enamel matrix derivative (experimental group) with a modified coronally advanced tunnel technique compared with subepithelial CTG (control group) could improve treatment outcomes for Miller class III multiple recessions 1-year post-therapy. In 20 patients with 139 recessions, the authors found that both treatments resulted in a root coverage of 82 % for test and 83 % for control groups. Stable results were obtained at 28 days, and there was no significant difference within and between groups for the position of the gingival margin and papilla after 28-days and up to 12-months post-surgery. The authors concluded that the modified coronally advanced tunnel technique provides predictable results for the treatment of Miller class III multiple recessions.
CTG vs. biomaterials
An adequate thickness of the gingival margin is the key to ensure long-term stability.10,11 As described, the most common and predictable procedure is an advanced coronal flap combined with a CTG. However, very often a patient with multiple recessions has a thin biotype, and, therefore, the harvesting of adequate CTG may be associated with increased patient morbidity, prolonged surgical time and postoperative complications.5 Attempts have been made to develop new biomaterials to replace CTG harvest.
Geistlich Mucograft® has been proposed as an alternative to subepithelial CTG in periodontal plastic surgery procedures. Its safety and clinical efficacy for root coverage procedures was reported in several preclinical12 and clinical studies.13,14
In 2013 Aroca et al. performed a 1-year prospective, randomized, controlled, split-mouth study to evaluate the clinical outcome when treating Miller class I and II multiple recessions using modified coronally advanced tunnel technique and using either Geistlich Mucograft® or CTG.5 At 1-year, compared with the baseline, both treatments resulted in statistically significant improvements for complete root coverage, mean recession coverage, keratinized tissue width and gingival thickness. The authors concluded that the use of collagen matrix may represent an alternative to CTG by reducing surgical time and patient morbidity.