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

21 de agosto de 2026 atualizado por: Merve Atak, Ankara University

Clinical, Histological, Biomolecular, and Ultrasonographic Analysis of the Efficacy of a Volume-Stable Collagen Matrix Versus an Autogenous Connective Tissue Graft in the Treatment of Peri-Implant Soft-Tissue Defects

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.

Visão geral do estudo

Descrição detalhada

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.

Tipo de estudo

Intervencional

Inscrição (Estimado)

22

Estágio

  • Não aplicável

Contactos e Locais

Esta seção fornece os detalhes de contato para aqueles que conduzem o estudo e informações sobre onde este estudo está sendo realizado.

Contato de estudo

Estude backup de contato

Locais de estudo

    • Yeni̇mahalle
      • Ankara, Yeni̇mahalle, Turquia (Türkiye), 06560
        • Recrutamento
        • Faculty of Dentistry, Ankara University
        • Contato:

Critérios de participação

Os pesquisadores procuram pessoas que se encaixem em uma determinada descrição, chamada de critérios de elegibilidade. Alguns exemplos desses critérios são a condição geral de saúde de uma pessoa ou tratamentos anteriores.

Critérios de elegibilidade

Idades elegíveis para estudo

  • Adulto
  • Adulto mais velho

Aceita Voluntários Saudáveis

Sim

Descrição

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

Plano de estudo

Esta seção fornece detalhes do plano de estudo, incluindo como o estudo é projetado e o que o estudo está medindo.

Como o estudo é projetado?

Detalhes do projeto

  • Finalidade Principal: Tratamento
  • Alocação: Randomizado
  • Modelo Intervencional: Atribuição Paralela
  • Mascaramento: Dobro

Armas e Intervenções

Grupo de Participantes / Braço
Intervenção / Tratamento
Experimental: VCMX Group
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).
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)
Comparador Ativo: CTG Group
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).
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)

O que o estudo está medindo?

Medidas de resultados primários

Medida de resultado
Descrição da medida
Prazo
peri-implant soft-tissue thickness
Prazo: Baseline, 1 week, 1 month, 3 months, and 6 months
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

Medidas de resultados secundários

Medida de resultado
Descrição da medida
Prazo
Peri-implant soft-tissue vascularization
Prazo: Baseline, 1 week, 1 month, 3 months, and 6 months
Peri-implant soft-tissue perfusion will be evaluated using Power Doppler ultrasonography (PDUS) with the same unit and probe, preoperatively (baseline) and postoperatively at 1 week, 1 month, 3 months, and 6 months. Quantitative analysis will use the device's integrated Color Quantification (CQ) module: a circular region of interest (ROI) 6 mm in diameter (area 28.274 mm²), originating from the alveolar crest margin, will be defined. Within this ROI, the proportion of colored (Power Doppler) pixels representing blood flow relative to the total number of pixels will be calculated to obtain a semi-quantitative Power Doppler pixel density . The outcome is the change in pixel density from baseline to 6 months, compared between the VCMX and CTG groups.
Baseline, 1 week, 1 month, 3 months, and 6 months
Ultrasonographic echo intensity of peri-implant soft tissue
Prazo: Baseline, 1 week, 1 month, 3 months, and 6 months
Tissue echogenicity will be evaluated preoperatively (baseline) and postoperatively at 1 week, 1 month, 3 months, and 6 months from static B-mode images obtained with the probe positioned longitudinally over the mid-buccal region of the edentulous site. Echo intensity will be measured in decibels (dB) using the unit's grayscale (echo-intensity) function. The ROI will extend 7 mm apically from the soft-tissue margin. As the device references echo intensity to the system's saturation level, soft-tissue reflections yield negative dB values; less negative values indicate higher echogenicity (denser, more organized tissue), and more negative values indicate hypoechoic/less dense tissue. Measurements will be performed by a single calibrated, blinded examiner, with intra-examiner reliability assessed beforehand. The outcome is the change in echo intensity from baseline to 6 months, compared between the VCMX and CTG groups.
Baseline, 1 week, 1 month, 3 months, and 6 months
Postoperative pain
Prazo: 1 week
Patient-rated pain intensity at 1 week, recorded on a Visual Analog Scale (VAS) anchored at 0 (no pain) and 10 (most severe pain). Compared between the VCMX and CTG groups.
1 week
Postoperative swelling
Prazo: 1 week
Patient-rated swelling at 1 week on a Visual Analog Scale (VAS) from 0 (no swelling) to 10 (most severe). Compared between the VCMX and CTG groups.
1 week
Postoperative fatigue
Prazo: 1 week
Patient-rated fatigue at 1 week on a Visual Analog Scale (VAS) from 0 (no fatigue) to 10 (most severe). Compared between the VCMX and CTG groups
1 week
Number of analgesic tablets consumed
Prazo: 1 week
Total number of analgesic tablets taken during the first postoperative week, recorded by patient self-report. Compared between the VCMX and CTG groups.
1 week
Early wound healing (Wound Healing Index, WHI)
Prazo: 1 week
Early wound healing at 1 week scored with the Wound Healing Index (Huang et al., 2005) based on edema, erythema, discomfort, flap dehiscence, and suppuration, from 1 (uneventful healing) to 3 (poor healing). Compared between the VCMX and CTG groups.
1 week
Soft-tissue appearance
Prazo: 6 months
Soft-tissue appearance at 6 months graded with the Aichelmann-Reidy et al. (2001) tissue-appearance system across five parameters (tissue consistency, contour, color match, scar formation, and integration with adjacent tissue), each scored against predefined criteria and summed into a total appearance score. Compared between the VCMX and CTG groups.
6 months
Patient satisfaction with appearance
Prazo: 6 months
Number of participants rating the appearance of the treated site as "satisfactory" versus "not satisfactory" at 6 months. Compared between the VCMX and CTG groups.
6 months
Patient satisfaction with experience
Prazo: 6 months
Number of participants rating their treatment experience as "satisfactory" versus "not satisfactory" at 6 months. Compared between the VCMX and CTG groups.
6 months
Histomorphological evaluation
Prazo: 6 months
Descriptive light-microscopic evaluation (hematoxylin-eosin and Masson's trichrome) of tissue architecture, integrity and cellular organization, extracellular matrix organization, and the presence of necrosis, edema, hemorrhage, inflammation, foreign-body reaction, and fibrosis.
6 months
Microvascular density
Prazo: 6 months
Number of vessels counted in the superficial connective tissue at x400 magnification (single field = 0.237 mm²) across three consecutive fields, averaged per specimen. Compared between the VCMX and CTG groups.
6 months
CD163
Prazo: 6 months
Number of CD163-positive cells counted at x400 magnification (single field = 0.237 mm²) across three hot-spot fields, averaged per specimen. Compared between the VCMX and CTG groups.
6 months
CD11c
Prazo: 6 months
Number of CD11c-positive cells counted at x400 magnification (single field = 0.237 mm²) across three hot-spot fields, averaged per specimen. Compared between the VCMX and CTG groups.
6 months
TIMP-1
Prazo: 6 months
Number of TIMP-1 positive cells counted at x400 magnification (single field = 0.237 mm²) across three hot-spot fields, averaged per specimen. Compared between the VCMX and CTG groups.
6 months
MMP-1
Prazo: 6 months
Number of MMP-1 positive cells counted at x400 magnification (single field = 0.237 mm²) across three hot-spot fields, averaged per specimen. Compared between the VCMX and CTG groups.
6 months
Collagen I
Prazo: 6 months
Immunohistochemical Collagen I staining, quantified as the percentage of positively stained area relative to the total microscopic field area. Compared between the VCMX and CTG groups.
6 months
Collagen III
Prazo: 6 months
Immunohistochemical Collagen III staining, quantified as the percentage of positively stained area relative to the total microscopic field area. Compared between the VCMX and CTG groups.
6 months

Colaboradores e Investigadores

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Patrocinador

Datas de registro do estudo

Essas datas acompanham o progresso do registro do estudo e os envios de resumo dos resultados para ClinicalTrials.gov. Os registros do estudo e os resultados relatados são revisados ​​pela National Library of Medicine (NLM) para garantir que atendam aos padrões específicos de controle de qualidade antes de serem publicados no site público.

Datas Principais do Estudo

Início do estudo (Real)

18 de dezembro de 2025

Conclusão Primária (Estimado)

1 de setembro de 2026

Conclusão do estudo (Estimado)

1 de setembro de 2026

Datas de inscrição no estudo

Enviado pela primeira vez

14 de agosto de 2026

Enviado pela primeira vez que atendeu aos critérios de CQ

21 de agosto de 2026

Primeira postagem (Real)

24 de agosto de 2026

Atualizações de registro de estudo

Última Atualização Postada (Real)

24 de agosto de 2026

Última atualização enviada que atendeu aos critérios de controle de qualidade

21 de agosto de 2026

Última verificação

1 de agosto de 2026

Mais Informações

Termos relacionados a este estudo

Outros números de identificação do estudo

  • İ03-222-25
  • TSA-2025-4380 (Número de outro subsídio/financiamento: Ankara University Scientific Research Projects Unit)

Plano para dados de participantes individuais (IPD)

Planeja compartilhar dados de participantes individuais (IPD)?

NÃO

Informações sobre medicamentos e dispositivos, documentos de estudo

Estuda um medicamento regulamentado pela FDA dos EUA

Não

Estuda um produto de dispositivo regulamentado pela FDA dos EUA

Não

Essas informações foram obtidas diretamente do site clinicaltrials.gov sem nenhuma alteração. Se você tiver alguma solicitação para alterar, remover ou atualizar os detalhes do seu estudo, entre em contato com register@clinicaltrials.gov. Assim que uma alteração for implementada em clinicaltrials.gov, ela também será atualizada automaticamente em nosso site .

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