Peri-implant Tissue Changes Using Dual Zone Concept with Connective Tissue Graft Versus Concentrated Growth Factor (A Randomized Clinical Trial)

Maintaining the natural esthetic appearance, particularly in the esthetic zone, together with the volume and contour of the soft tissue in harmony with the surrounding teeth soft tissue, is believed to be critical. However, postponing implant placement until hard and soft tissues have fully healed usually necessitates additional surgical intervention steps, such as guided bone regeneration or ridge splitting, or implant placement in undesirable positions with a low esthetic appearance to overcome alveolar ridge resorption.

In clinical practice, immediate implant placement (IIP) in the esthetic zone has been regarded as an ongoing concern. Immediate implant placement (IIP) aims to minimize the duration of therapy overall, cost-effectiveness, and patient aesthetic expectations. However, the physician needs to be aware of potential risks and undesirable effects associated with this surgery, such as early implant loss and dimensional alterations in soft and hard tissues. Clinical research continues to advance to improve predictability and minimize the occurrence of undesirable consequences following IIP due to evolving patients' esthetic demands and expectations.

Over the years, numerous surgical techniques have been proposed to preserve the soft and hard tissues in the esthetic zone. These techniques include proper 3D implant positioning, flapless approach, the addition of bone graft, the use of grafts containing growth factors such as concentrated growth factor (CGF) and platelet-rich fibrin (PRF) membranes, the application of connective tissue grafts (CTG), the socket shield technique, or the use of customized healing abutments. In order to offset the peri-implant tissue reduction, various treatments were also devised, including vestibular socket therapy, the dual-zone concept (DZ), and immediate dentoalveolar restoration.

From the above-mentioned approaches, Dual Zone technique was utilized in conjunction with CTG, and CGF graft were primarily advised for peri-implant soft tissue phenotypic preservation, stability, and health. The dual-zone (DZ) concept was developed to reduce the amount of buccal contour change at the extraction site while enhancing the thickness of the peri- implant soft tissues by filling the buccal gap with bone graft in two zones: the bone zone up to the crest of the socket bone and the soft tissue zone. To illustrate, graft particles are absorbed into tissues, increasing their thickness while also providing stability and maintaining soft tissue volume. As a result, the DZ concept aims to maintain the gingival contour while providing excellent soft tissue esthetics.

Connective tissue graft (CTG) and concentrated growth factor (CGF) graft are two commonly used materials for soft tissue augmentation in implant dentistry. CTG has a long history of success in improving soft tissue volume and quality around dental implants by forming a scaffold for cell migration and tissue regeneration. On the other hand, CGF, a newer autologous platelet concentrate rich in growth factors, has demonstrated promising results in stimulating tissue healing and regeneration, potentially outperforming standard graft materials.