Volume-Stable Collagen Matrix vs. Connective Tissue Graft for Peri-Implant Soft Tissue Defects

NCT07782125 | Recruiting

• 2 other identifiers: İ03-222-25TSA-2025-4380
• Study Type: interventional
• Target: 22
• Locations: 1 country
• Sites: 1

Brief Summary

Peri-implant soft-tissue defects will be treated with either a volume-stable collagen matrix (VCMX; test group) or an autogenous connective tissue graft (CTG; control group) following implant placement in patients with a single missing tooth. After a mid-crestal incision and full-thickness flap elevation, the graft material will be positioned over the crest beneath the buccal flap and stabilized, followed by tension-free primary closure. Peri-implant soft-tissue thickness, echo intensity, and vascularization will be assessed non-invasively using high-resolution intraoral ultrasonography and Power Doppler imaging. Clinical periodontal parameters and patient-reported outcomes, including pain perception (visual analog scale), swelling, fatigue, analgesic consumption, and wound healing, will be recorded. These outcomes will be evaluated at baseline and on the 1st week, 1st, 3rd, and 6th months. At the 6th month, gingival biopsy samples obtained during healing abutment placement will be evaluated histologically and immunohistochemically (CD11c, CD163, COL1, COL3, MMP-1, TIMP-1) to compare the biological integration of the two graft materials.

Conditions

Dental Implantation; Peri-Implant Soft Tissue Deficiency; Soft Tissue Augmentation

Outcome Measures

Primary Outcomes (1)

• peri-implant soft-tissue thickness

  Peri-implant buccal soft-tissue thickness will be measured non-invasively using high-resolution intraoral ultrasonography (LOGIQ P10 XDClear R4.5, GE Healthcare) with an L8-18i-RS high-frequency linear "hockey-stick" probe (8 MHz). Measurements will be repeated preoperatively (baseline) and postoperatively at 1 week, 1 month, 3 months, and 6 months. On static B-mode images, linear soft-tissue thickness will be assessed at three levels 1.5, 3, and 5 mm apical to the alveolar crest margin and recorded in millimeters by a single calibrated examiner blinded to group allocation. The primary outcome is the change in linear soft-tissue thickness from baseline to 6 months, compared between the VCMX and CTG groups.

  Baseline, 1 week, 1 month, 3 months, and 6 months

Secondary Outcomes (18)

• Peri-implant soft-tissue vascularization

  Baseline, 1 week, 1 month, 3 months, and 6 months

• Ultrasonographic echo intensity of peri-implant soft tissue

  Baseline, 1 week, 1 month, 3 months, and 6 months

• Postoperative pain

  1 week

• Postoperative swelling

  1 week

• Postoperative fatigue

  1 week

Study Arms (2)

VCMX Group

EXPERIMENTAL

Soft-tissue augmentation will be performed using a volume-stable collagen matrix (VCMX). Under local anesthesia, a mid-crestal incision combined with sulcular incisions will be made, and a full-thickness flap will be elevated with periosteal releasing incisions to eliminate tension. Implants will be placed according to prosthetic and surgical principles and covered with a cover screw. The VCMX (15×20×3 mm) will be trimmed to the defect size, positioned over the crest beneath the buccal flap, and stabilized with simple interrupted sutures (6-0 polypropylene). Tension-free primary flap closure will be achieved with simple interrupted sutures (5-0 polypropylene).

Device: Volume-stable collagen matrix

CTG Group

ACTIVE COMPARATOR

Soft-tissue augmentation will be performed using an autogenous connective tissue graft (CTG). Under local anesthesia, a mid-crestal incision combined with sulcular incisions will be made, and a full-thickness flap will be elevated with periosteal releasing incisions to eliminate tension. Implants will be placed according to prosthetic and surgical principles and covered with a cover screw. A CTG harvested using the extraoral de-epithelialization technique will be positioned over the crest beneath the buccal flap and stabilized with simple interrupted sutures (6-0 polypropylene). Tension-free primary flap closure will be achieved with simple interrupted sutures (5-0 polypropylene).

Procedure: Connective tissue graft

Interventions

Connective tissue graft PROCEDURE

An autogenous connective tissue graft harvested from the palate using the extraoral de-epithelialization technique will be placed over the crest beneath the buccal flap and stabilized with simple interrupted sutures (6-0 polypropylene) to augment peri-implant soft-tissue thickness. (control group)

CTG Group

Volume-stable collagen matrix DEVICE

A volume-stable porcine-derived collagen matrix (15×20×3 mm) will be trimmed to the defect size, placed over the crest beneath the buccal flap, and stabilized with simple interrupted sutures (6-0 polypropylene) to augment peri-implant soft-tissue thickness. (test group)

VCMX Group

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age \>18 years
• Periodontal health confirmed according to the 2017 World Workshop criteria (BOP \<10%, PD ≤3 mm, absence of gingival inflammation, and good oral hygiene) (Tonetti et al., 2018)
• Requirement of implant placement and soft-tissue augmentation for a single missing tooth in the anterior region
• Bleeding on probing \<30% at the adjacent teeth (Thoma et al., 2016)
• Compliance with the study protocol and follow-up visits

You may not qualify if:

• Siebert Class II or Class III defects
• History of surgery at the treated site
• Untreated periodontitis or peri-implantitis
• Current smoking or smoking within the previous five years
• Systemic conditions (that may impair healing)
• Pregnancy or lactation
• Allergy to the materials/drugs used
• Drug use affecting mucosal healing
• History of antibiotic therapy within the previous six months

Sponsors & Collaborators

• Ankara University: lead

Study Sites (1)

Faculty of Dentistry, Ankara University

Ankara, Yeni̇mahalle, 06560, Turkey (Türkiye)

RECRUITING

Central Study Contacts

Sivge Kurgan, PHD

CONTACT

+905325495235; sivgeakgun@gmail.com

Merve Atak, DDS

CONTACT

+905054227474; merve.attak@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Research Assistant, Department of Periodontology

Study Record Dates

• First Submitted: August 14, 2026
• First Posted: August 24, 2026
• Study Start: December 18, 2025
• Primary Completion (Estimated): September 1, 2026
• Study Completion (Estimated): September 1, 2026
• Last Updated: August 24, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)