Overview
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.
Description
Adequate peri-implant soft-tissue thickness is important for both esthetic outcomes and the long-term maintenance of peri-implant health, as thin mucosa has been associated with increased marginal bone loss. Although the autogenous connective tissue graft is considered the gold standard for soft-tissue augmentation, it entails disadvantages such as the need for a second surgical site and donor-site morbidity. The volume-stable collagen matrix has been proposed as an alternative that eliminates the need for a donor site; however, comparative data based on ultrasonographic, histological, and immunohistochemical evidence remain limited. This study aims to compare VCMX and CTG using a multidimensional approach.
The study is designed as a single-center, randomized, controlled clinical trial to be conducted at the Department of Periodontology, Faculty of Dentistry, Ankara University. Participants meeting the eligibility criteria will be allocated to the test (VCMX) and control (CTG) groups. All surgical and clinical procedures will be performed according to standardized protocols, and all data will be recorded prospectively.
The evaluation will adopt a multidimensional methodological approach: the assessment of quantitative data obtained by high-resolution intraoral ultrasonography (soft-tissue thickness, vascularization, and echo intensity) together with histological and immunohistochemical findings constitutes the novel aspect of this study. The primary outcome will be the change in ultrasonographic soft-tissue thickness, whereas the secondary outcomes will comprise vascularization, echo intensity, clinical periodontal parameters, patient-reported outcomes, and the histological/immunohistochemical evaluation of graft integration. In this way, the two graft materials will be compared not only in terms of dimensional gain but also with respect to biological integration and tissue quality.
Eligibility
Inclusion Criteria:
- 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
Exclusion Criteria:
- 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
