*3.1.1 Connective tissue harvesting with the preparation of primary flap- subepithelial connective tissue graft (sCTG)*

### *3.1.1.1 The role of the primary flap*

The main purpose of the primary flap is the protection of the donor wound region. At the end of the surgical procedure, the primary flap is repositioned and sutured in its original position, completely covering the wound area beneath it. Thus, thanks to the primary flap, the wound area is healing with primary intention. This will result in a reduced time of haling and postoperative morbidity. In case when the primary flap has reduced vascularity as a consequence of a surgical error during flap preparation (flap thinner than 1 mm, perforation of the flap) it will necrotize, leaving the donor area unprotected and left to heal with secondary intention 26, 25, 40, 42, 43, 47, 52 (**Figure 5**).

#### *3.1.1.2 Donor area*

The donor area for CTG graft harvesting is located in the palatal masticatory mucosa extending:


#### **Figure 5.**

*sCTG harvesting. After the harvesting procedure of the sCTG the primary flap is repositioned in its original position. The primary flap protects the wound beneath it, enabling primary healing of the donor area.*

3.The coronal incision is displaced 2 mm from the CEJ to prevent soft tissue recession on the palatal side of the adjacent teeth.

In patients with a flat palate, the palatine artery is closer to the CEJ, located 7 mm apically of the CEJ of adjacent teeth resulting in a limited height of the CTG [25, 26, 56–59].

Another limiting factor for CTG harvesting with the preparation of the primary flap is the palatal soft tissue thickness. The palatal soft tissue should be at least 3 mm thick, to allow the preparation of primary flap thick 1.0–1.5 mm and harvesting of 1.5– 2.0 mm thick CTG. Therefore, before starting the grafting procedure, it is advisable to examine the thickness of the donor area [42, 60–63].

In case when inadequate palatal soft tissue thickness is present, three different solutions are available—(1) two-step procedures: Augmentation of the palatal soft tissue with the collagen sponge and after 8 weeks harvesting of the sCTG from the thickened donor site [60–62], (2) different grafting techniques of the CTG (de-epithelized CTG) [42, 48, 64], and (3) use of a substitutional soft tissue graft (allogenic or xenogenic soft tissue substitute graft) [65–68].

#### *3.1.1.3 Surgical technique*

The first part of the harvesting procedure consists of the preparation of the primary flap. The dissection of the primary flap starts with a horizontal incision 1.0– 1.5 mm deep, 2 mm apical from the cementoenamel junction, and perpendicular to the mucosal surface. The blade angulation is changed to approximately 135° and a splitthickness flap is prepared in the apical direction. With the progression of the flap preparation, the angle of the blade is flattened until it becomes parallel with the gingival surface. The dissection is controlled from the external aspect of the flap in order to prevent flap perforation. The partial-thickness flap preparations end after reaching 8 mm from the first horizontal incision, this is 10 mm apically from the

cementoenamel junction, leaving a safe zone with 2 mm of distance from the possible location of blood vessels. This will result in the maximal apico-coronal graft dimension of 8 mm.

The primary flap is prepared with the sharp dissection, in a split-thickness manner. During the partial-thickness preparation, the blade is oriented parallel with the mucosal surface to prevent perforations or overthinning of the primary flap. Care must be taken to leave the minimum residual thickness of the primary flap at least 1.5 mm, otherwise it could be necrotized.

After finishing its dissection, the primary flap is partially reflected and the connective tissue graft is dissected just beneath it. It is suggested to place the coronal dissection line 1.0–1.5 mm apical from the coronal incision line of the primary flap. This will result in a 1.0–1.5 mm connective tissue band along the coronal incision line, improving the healing of the primary flap, but at the same reducing the apico-coronal dimension of the connective tissue graft from the maximal 8 to 7 or 6.5 mm [26, 44, 69–71].

The connective tissue graft can be harvested with or without the periosteum layer depending on if it is inner surface is prepared with sharp or blunt dissection. The CTG with the periosteum has better mechanical stability and better clinical handling. On the other hand, leaving a periosteal surface on the bone in the donor area will improve the healing of the primary flap. In clinical situations where the primary flap was prepared with reduced thickness (equal or less than the lower value of the recommended thickness) or perforated during dissection, it could be advisable to leave the periosteum covering the bone surface [26, 44, 69–71].

After the completion of the harvesting procedure, the primary flap is repositioned and sutured in its original position. Although, cross matters or a combination of parallel and cross sutures were recommended [26, 69, 70], it seems that the suturing technique does not have an influence on early wound healing in the donor area [72].

Once the CTG is harvested it must be kept in a moist environment, usually draped in wet gauze, until is transferred to the recipient site [26, 69–71].

#### **3.2 Connective tissue pedicle flaps**

Connective tissue can be harvested from the palatal donor site as a free graft or pedicle graft. Free grafts are completely dissected from the donor site while pedicle flaps remain attached by one part to the donor site. In that way, they retain the vascularization of the donor site which will influence positively the graft volume stability reducing the shrinkage of the graft postoperatively and improving the outcome of the augmentation procedure [44, 45, 73].

Pedicle palatal connective tissue was first described in 1980 [74].

The preparation of the primary flap is equal to the primary flap for the free connective tissue graft. The only difference is the length of the primary flap which can be elongated if the defect is located in the frontal region [45]. The main variation to conventional free connective tissue graft is the harvesting of the CTG. During the preparation of the pedicle, the connective tissue graft below the primary flap is freed from the rest of the palatal tissue on three sides, while one side remains attached to it [45, 73, 75–77].

Different modifications of this technique have been described, which can be divided into two groups—roll techniques and vascularized interpositional periosteal connective tissue flap. In the first group, the pedicle is attached by its coronal part to the buccal flap and rolled under the buccal flap. This flap is used mostly for minor augmentation of the buccal PIS during the single implant uncovering procedure

[78–80]. Other indications include soft tissue augmentation for pontic site development [81, 82] and multiple implants PIS augmentation and pontic site development at implant uncover procedure (**Figures 6–11**) [83].

The vascularized interpositional periosteal connective tissue flap (VIP-CTG) consists of a connective tissue pedicle that remains attached to the palatal tissue on the

#### **Figure 6.**

*Palatal roll technique for PIS augmentation around the single implant at uncovering procedure. Initial situation.*

**Figure 7.** *The primary flap has been prepared.*

#### **Figure 8.**

*The CTG remains attached to the buccal flap, while it is dissected from the adjacent palatal soft tissue on the apical, mesial, and distal side.*

#### **Figure 9.**

*The CTG pedicle graft has been rotated beneath the buccal flap and sutured in this position. The thickness of the buccal PIS has been visibly augmented.*

#### **Figure 10.** *Definitive zircon-ceramic screw-retained crown 14.*

**Figure 11.** *Two years follow up.*

distal or mesial side, depending on the defect location. It can be used for more pronounced soft-tissue defect augmentation (horizontal and vertical), allowing grafting of large soft tissue defects with only one procedure. Furthermore, VIP-CTG can be used for simultaneous soft and hard tissue augmentation procedures, reducing patient treatment time and morbidity. This procedure is indicated before implant placement, concomitant with implant placement, or during the implant osseointegration period [45, 75, 76] or pontic site development (**Figures 12–18**) [44, 73, 74, 84].

**Figure 12.** *VIP-CTG for the treatment of the vertical soft-tissue defect in an esthetical demanding situation. Initial situation.*

#### **Figure 13.**

*The incision line of the primary flap is extending mesially until the defect site is located in the region of the central incisor. The VIP-CTG is dissected from the rest of the palatal soft tissue on three sides (distal, coronal, apical) and rolled over the buccal soft tissue in order to determine the size of the buccal pouch that will be prepared. The mesial side of the VIP-CTG will remain attached to the adjacent palatal soft tissue.*

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

#### **Figure 14.**

*With the help of two horizontal mattress sutures the VIP-CTG will be positioned and stabilized inside the pouch.*

#### **Figure 15.**

*Suturing of the donor and defect area. The donor and the defect sites will heal by primary intention.*

#### **Figure 16.**

*Final appearance of the PIS after soft tissue conditioning with provisional crowns-frontal view.*

**Figure 18.** *Final screw-retained zirconia-ceramic crowns 21, 11.*
