Evaluation of Buccal Pedicle Flap, Connective Tissue Graft and Acellular Dermal Matrix for Volumetric Augmentation of Peri-implant Mucosa

The aim of the study is to evaluate the efficacy of different soft tissue grafting techniques including buccal pedicle flap alone, free connective tissue graft and acellular dermal matrix for volumetric augmentation of peri-implant mucosa during the second stage implant surgery.

Soft tissue grafting around dental implants has been recommended to enhance functional, biological, and esthetic outcomes. As a thick peri-implant mucosa is of importance to prevent recession, color alterations, bone remodeling and promote "creeping attachment". Two major indications include the increase of the KM width and the increase of soft tissue volume using autogenous or alternative type grafts.

Several techniques have been proposed to augment the volume of the mucosa to achieve the so-called pink esthetics: connective tissue grafts, lyophilized allogenic soft tissue grafts, porcine collagen matrix, free gingival grafts, a combination of grafting and vestibuloplasty, strip gingival autografts, tissue engineered fibroblasts, allograft, collagen matrices, and the use of the buccal pedicle flap.

Among surgical techniques, the proposed modified buccal pedicle flap was demonstrated to perform well in terms of decreased morbidity, maintenance of blood supply, stabilization of the pedicle, superior haemostasis, and speed of treatment. However, a possible drawback may be related to the original thickness of the flap since a thin mucosa phenotype may be more prompt to perforation when in contact with a cross-linked collagen matrix.

The autologous subepithelial connective tissue graft (sCTG) is generally regarded as the gold standard for soft tissue augmentation around natural teeth and dental implants. However, harvesting an autologous soft tissue graft necessarily entails additional preoperative preparation, a second surgical site, longer operative duration, and increased morbidity, regardless of the surgical technique employed and the expertise of the operator.

Another alternative for autogenous grafting is the acellular dermal matrix (ADM) allograft that is derived from human skin. ADM, originally used for treating burn wounds , is an epithelium free, freeze-dried matrix containing types I and III collagen bundles where elastic fibers are its main components . ADM acts as a bioactive scaffold that integrates in host tissue and permits the migration of fibroblasts and epithelial and endothelial cells through vascular channels of the recipient sites . Since its initial use, ADM has been widely used in dental practice, in particular for soft tissue grafting of gingival recession or to change the quality of peri-implant/teeth mucosa.

Eligibility Criteria:
Inclusion Criteria:

* Patient age : above 20 years with single or multiple edentulous spaces
* Healthy periodontium.
* Thin periodontal phenotype.
* Non smoker.
* Adequate amount of basal bone to achieve primary stability.
* Patient who is able to understand and sign a written consent.
* Patient with good oral hygiene measures and plaque index\<1

Exclusion Criteria:

* • Presence of systemic , local disease or any medication that would compromise healing.

  * Presence of infection or pathology related to the surgical area.
  * Pregnancy and lactation.