CTG vs VCMX for Peri-implant Soft Tissue Thickness

Peri-implant Soft Tissue Thickness in the Aesthetic Zone: A Randomized Controlled Clinical Trial Comparing Connective Tissue Grafts and a Volume-Stable Collagen Matrix

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.

Study Overview

• Status: Completed
• Conditions: Dental Implants; Missing Tooth/Teeth; Peri-Implant Tissues
• Intervention / Treatment: Procedure: Connective Tissue Graft; Device: Volume-Stable Collagen Matrix

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 36
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Poland
  • Wroclaw, Poland
    • Medyczne Centrum Innowacji Wrocław (Wrocław Medical Innovation Center), formerly operating as Akademicka Akademicka Poliklinika Stomatologiczna

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Connective Tissue Graft (CTG); Participants received peri-implant soft tissue augmentation using an autogenous subepithelial connective tissue graft harvested from the palate and placed at the implant site according to a standardized surgical protocol.	Procedure: Connective Tissue Graft; An autogenous subepithelial connective tissue graft harvested from the palatal donor site and used for peri-implant soft tissue augmentation according to a standardized surgical protocol.
Experimental: Volume-Stable Collagen Matrix (VCMX); Participants received peri-implant soft tissue augmentation using a volume-stable collagen matrix placed at the implant site according to the manufacturer's instructions and a standardized surgical protocol.	Device: Volume-Stable Collagen Matrix; A volume-stable collagen matrix used for peri-implant soft tissue augmentation according to the manufacturer's instructions and a standardized surgical protocol.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in peri-implant soft tissue thickness	Change in peri-implant soft tissue thickness measured at the implant site using a standardized clinical measurement method.	Baseline and 6 months after soft tissue augmentation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Peri-implant soft tissue thickness at additional follow-up time points	Peri-implant soft tissue thickness assessed at predefined follow-up visits after soft tissue augmentation.	Baseline, 3 months, and 12 months after augmentation

Collaborators and Investigators

• Sponsor: Medical Innovation Center Wroclaw
• Collaborators: Geistlich Pharma AG

Study record dates

Study Major Dates

• Study Start (Actual): January 2, 2022
• Primary Completion (Actual): April 10, 2025
• Study Completion (Actual): April 19, 2025

Study Registration Dates

• First Submitted: December 23, 2025
• First Submitted That Met QC Criteria: December 23, 2025
• First Posted (Estimated): January 7, 2026

Study Record Updates

• Last Update Posted (Estimated): January 16, 2026
• Last Update Submitted That Met QC Criteria: January 14, 2026
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: collagen matrix; CTG; peri-implant soft tissue; connective tissue graft,; VCMX
• Additional Relevant MeSH Terms: Stomatognathic Diseases; Tooth Diseases; Stomatognathic System Abnormalities; Congenital Abnormalities; Tooth Abnormalities; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Anodontia
• Other Study ID Numbers: 400166

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: 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.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No