This investigator-initiated randomized controlled clinical trial evaluated changes in peri-implant soft tissue thickness in the aesthetic zone following soft tissue augmentation. Adult patients requiring single-tooth implant therapy in the aesthetic zone were randomly assigned to receive either an autogenous connective tissue graft (CTG) or a volume-stable collagen matrix (VCMX) at the implant site.

The primary objective of the study was to compare changes in peri-implant soft tissue thickness between the two treatment approaches over time. Secondary objectives included evaluation of aesthetic outcomes, clinical parameters, and treatment-related complications.

The study was conducted at a single academic clinical center in Poland in accordance with Good Clinical Practice, the Declaration of Helsinki, and applicable ethical and regulatory requirements. All participants provided written informed consent prior to enrollment.

This investigator-initiated, single-center, randomized controlled clinical trial was designed to assess the effectiveness of two different soft tissue augmentation approaches on peri-implant soft tissue thickness in the aesthetic zone. The study compared the use of an autogenous connective tissue graft (CTG) with a volume-stable collagen matrix (VCMX) in patients undergoing single-tooth implant therapy.

Eligible adult patients presenting with an indication for peri-implant soft tissue augmentation in the aesthetic zone were enrolled and randomly allocated in a 1:1 ratio to one of the two intervention groups. In the CTG group, a subepithelial connective tissue graft was harvested from the palate and placed at the peri-implant site. In the VCMX group, a commercially available volume-stable collagen matrix was used for soft tissue augmentation according to the manufacturer's instructions.

Standardized surgical and prosthetic protocols were applied in both groups. Clinical examinations and outcome assessments were performed at predefined follow-up visits. The primary outcome measure was the change in peri-implant soft tissue thickness measured at the implant site over time. Secondary outcome measures included additional clinical parameters, aesthetic outcomes, patient-reported outcomes, and the incidence of adverse events or complications.

The study protocol, patient information sheet, and informed consent form were approved by the Bioethics Committee of Wroclaw Medical University prior to study initiation. The study was conducted in compliance with Good Clinical Practice guidelines, ISO 14155, and the principles of the Declaration of Helsinki. All participants provided written informed consent before any study-related procedures were performed.

Inclusion Criteria:

• Adults aged 18 years or older.
• Single-tooth edentulism in the aesthetic zone of the maxilla or mandible, bordered by natural teeth on both sides.
• Bilateral two-tooth edentulism accepted only when implants were placed in separate quadrants.
• Indication for dental implant placement with peri-implant soft tissue augmentation.
• Adequate bone volume at the implant site confirmed radiographically.
• Baseline peri-implant soft tissue thickness suitable for augmentation.
• Minimum height of keratinized tissue of at least 2 mm.
• Good oral hygiene and periodontal health.
• Ability and willingness to provide written informed consent.

Exclusion Criteria:

• Previous bone grafting procedures at the intended implant site.
• Severe periodontal disease or untreated oral infection.
• Bruxism or heavy smoking.
• Systemic diseases or conditions that could impair wound healing or bone metabolism.
• History of radiotherapy in the head and neck region.
• Previous or ongoing bisphosphonate therapy.
• Uncontrolled diabetes mellitus.
• Pregnancy or breastfeeding.
• Use of medications known to interfere with soft tissue healing.

Individual participant data will not be shared due to data protection and confidentiality considerations, and because informed consent for public data sharing was not obtained from participants.

Clinical outcome assessments were performed by an independent examiner who not involved in the surgical procedures unaware of group allocation.