Treatment of Multiple Recession-Type Defects Using Tunnel technique with Acellular Dermal Matrix

The American Academy of Periodontology 1 has defined marginal tissue recession as an acquired deformity with the gingival margin being located apical to the cementoenamel junction (CEJ), resulting in exposed root surface and loss of attached gingiva. Gingival recession is a common feature in populations with high as well as poor standards of oral hygiene 2 . Many factors have been proposed to influence the development of marginal tissue recession, in patients with high standards of oral hygiene 2, 3 and may be associated with mechanical factors such as traumatic tooth-brushing 4 and orthodontic movement 5 , even if no definitive evidence is currently available 6 . Different techniques has been developed to attain root coverage, including free gingival graft (FGG) 7,8 , sliding flaps 9,10 , double papilla grafts 11 , connective tissue grafts (CTGs), 12 coronally positioned flaps 13,14 , coronal positioning of previously placed FGG 15,16 , and guided tissue regeneration. Recently, the association of the enamel matrix derivative with a coronally positioned flap has also been evaluated for the root coverage 17, 18 . Research has demonstrated superior esthetics and predictable outcomes in treating gingival recession in terms of the percentage of root coverage (RC) when a free autogenous connective tissue graft (CTG) is utilized 19, 20 , while a free gingival graft (FGG) remains the chosen method in augmenting the zone of keratinized gingiva 21, 22 . The disadvantages of harvesting free autogenous soft tissue grafts lie in the postoperative discomfort associated with an extra surgical site, as well as the limitations of available donor tissue. Consequently, several nonvital allograft alternatives have been introduced. These include a preserved sclera tissue graft 13, 24 , lyophilized homologous dura mater 25-27 , and absorbable and non-absorbable membranes 28-31 . Over the last few years, several studies have evaluated the effect of acellular dermal matrix (ADM) for mucogingival surgery with promising results 3247 . The healing process observed in the allograft is similar to that seen in autogenous grafts 48, 49 . In 2005, a Meta analysis of eight randomly controlled clinical trials showed no statistically significant differences between groups (ADM and CTG) for measured outcomes: