Xenogenic Collagen Matrix vs. Connective Tissue Graft for Soft Tissue Augmentation Around Early Maxillary Implants

Dental implants in the anterior maxillary region (esthetic zone) are commonly used to replace missing teeth. When implants are placed using the early placement protocol (typically 4-8 weeks after tooth extraction), additional soft tissue volume may be required to ensure an esthetically pleasing and functionally stable result.

Soft tissue augmentation can be achieved using:

Subepithelial connective tissue grafts (SCTG): A technique that involves harvesting tissue from the patient's own palate and placing it around the implant to improve gingival thickness and contour.

Xenogeneic collagen matrix (XCM): A biocompatible, animal-derived collagen scaffold designed to substitute for autologous tissue, reducing patient morbidity and surgical time.

This study is a prospective, randomized, controlled, parallel-arm clinical trial conducted at Minia University, Faculty of Dentistry. Eligible patients missing a single tooth in the anterior maxilla with a thin gingival biotype and requiring early implant placement were recruited. A total of 20 patients were randomly assigned into two groups (10 per group):

Group 1 (Control): Received subepithelial connective tissue graft harvested from the palate using the single-incision technique.

Group 2 (Test): Received xenogeneic collagen matrix (Mucoderm®) adapted and inserted into the grafting site.

Outcome Measures:

Primary Outcome:

Change in gingival thickness (GT) at 12 months post-surgery, measured via transgingival probing using a standardized protocol.

Secondary Outcomes:

Change in width of keratinized tissue (KTW)

Esthetic outcome (using clinical photographs and standardized scoring systems, e.g., Pink Esthetic Score)

Post-operative healing and complications

Patient-reported outcomes regarding comfort, pain, and satisfaction (using Visual Analog Scale questionnaires)

Clinical and radiographic assessments were performed at baseline, 6 months, and 12 months post-implant placement.

Ethical approval was obtained from the Research Ethics Committee of Minia University, and all participants provided informed consent. The study adheres to the Declaration of Helsinki and ICH-GCP guidelines.

This research aims to provide evidence on whether xenogeneic collagen matrix can serve as a viable, less invasive alternative to autogenous tissue grafts in implant dentistry, especially for cases with esthetic demand and thin soft tissue biotype.

**Inclusion Criteria:**

• Non-restorable or hopeless teeth from maxillary anterior to first premolar due to one or more of the following:
• Extensive caries
• Root fractures
• Inability to perform functional crown lengthening due to gingival zenith line with high gingival display
• Improper crown-to-root ratio due to bone removal leading to aesthetic or restorative failure
• Patients aged 25-55 years
• Both male and female patients
• Thin tissue biotype

**Exclusion Criteria:**

• Pregnant women
• Smokers
• Presence of persistent chronic infection at the implant site
• Patients in the growth phase with partially erupted teeth
• Patients with parafunctional habits such as bruxism or clenching that may overload the implant
• Patients with insufficient vertical inter-arch space in centric occlusion to accommodate restorative components