**4. Free gingival graft (FGG)**

Soft tissue graft consisting of epithelial and connective tissue layer which is completely detached from the rest of the palatal soft tissue is defined as a free gingival graft (FGG) [40].

#### *Peri-Implant Soft Tissue Augmentation DOI: http://dx.doi.org/10.5772/intechopen.101336*

The FGG was introduced in 1966 [87]. Historically, FGG was used to expand the band of keratinized gingiva around teeth [32], cover exposed root surfaces [88], soft tissue augmentation of edentulous ridges [89, 90], and expand the band of keratinized tissue around implants [91]. Since the esthetic appearance of the augmented tissue is poor due to inadequate color blending with the adjacent soft tissue and a "patch" like appearance, today FGG grafts are used mostly to increase the band of keratinized mucosa around implants in nonesthetic areas. Other indications for FGG are seldom performed only in nonesthetic areas 38, 40. The combination of apically positioned flap and autogenous graft is considered the gold standard technique for increasing the width of keratinized mucosa around implants [15].

#### **4.1 Recipient site preparation**

The recipient site is prepared with the apically positioned flap technique. A split-thickness flap is prepared along the mucogingival border. Usually, the flap design consists of a horizontal incision and two vertical incisions that are elongated to or apically to the mucogingival border depending on the amount of the apical displacement of the partial-thickness flap. The split-thickness flap is prepared with sharp dissection in the apical direction taking care to leave intact periosteal surface covering the bone; a 15C or 12D blade is used. In order to prevent perforations of the flap, the blade is oriented parallel with the mucosal surface during the dissection. Additionally, the progression of the flap dissection is monitored from the external flap surface. Muscle attachment, loose connective tissue fibers are removed from the periosteal surface. Care is taken to prepare an even surface that will allow an intimate contact of the graft with the vascularized surface. After the partial-thickness flap has been prepared, the flap is sutured in a new apical position. Sutures must engage the flap and the rigid periosteal surface in order to stabilize the flap [59]. The FGG is stabilized on the exposed periosteal surface with sutures or cyanoacrylate [40, 92]. After stabilization, the graft must be completely immobile, intimately adapted to the periosteal surface with no dead space remaining between the inner surface of the graft and the periosteal surface otherwise plasmatic imbibition and neovascularization bill be hindered. Furthermore, care must be taken to harvest an FGG with an even thickness to allow even precise adaptation to the recipient site throughout the inner surface of the graft. If present, fat tissue should be cut out from the FGG as it can slow down or prevent revascularization of the flap [25, 31, 40, 64].
