Cross-linked Volume-stable Collagen Matrix Versus Connective Tissue Graft at Implant Site.

Study Overview
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Brief Summary
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Recent data suggested that an adequate volume of Keratinized Tissue (KT) around dental implant is a key factor to obtain aesthetic outcomes and to support easy long-term maintenance. The aim of this RCT is to test the volume-stable collagen matrix (VCMX) vs the Connective Tissue Graft (CTG) for peri-implant soft tissue augmentation during implant uncovering.

Official Title
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Cross-linked Volume-stable Collagen Matrix Versus Connective Tissue Graft for Soft Tissue Augmentation at Implant Site. A Comparative, Multicentre Randomized Clinical Trial

Conditions
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Edentulous Alveolar Ridge Atrophy, Soft Tissue Augmentation at Dental Implants

Intervention / Treatment
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* Device: VCMX
* Procedure: CTG


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age ≥18 years. No systemic diseases or pregnancy. Self-reported smoking ≤10 cigarettes/day. No probing depths ≥5 mm Full-mouth plaque score (FMPS) and full-mouth bleeding score (FMBS) ≤15% (measured at four sites per tooth). Single dental implant with a scheduled for soft tissue augmentation procedure at the time of uncovering. Need of soft tissue augmentation for aesthetic purpose and/or functional reasons No previous soft tissue augmentation procedure at experimental site. Exclusion Criteria: General contraindications for dental and/or surgical treatments Concurrent or previous immunosuppressant, bisphosphonate or high dose corticosteroid therapy Inflammatory and autoimmune disease of oral cavity History of myeloma, respiratory tract cancer, breast cancer, prostate cancer or kidney cancer requiring chemotherapy or radiotherapy within the past five years Radiotherapy of head area Disease or condition affecting connective tissue metabolism (e.g. disease of arteries in the operating zone, bone metabolic diseases, alcohol abuse, treatment with anticoagulants) Any systemic diseases that affect bone metabolism (e.g thyroid dysfunction, autoimmune disease) Untreated acute periodontal disease Patients who smoke more than 10 cigarettes/day will be excluded from the study Diabetes Allergy to the collagen Pregnant or lactating women Women of child bearing age, not using a highly effective method of birth control Participation in an investigational device, drug or biologic study within the last 24 weeks prior to the study start

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: VCMX<br>All patients will be treated by scaling/root planing to obtain infection control if needed. In addition, patients will receive oral hygiene instructions. The test group will be treated with add of VCMX. Following the local anesthesia, a split thickness flap will be raised-up to uncover the implant screw. Care will be taken to preserve pre-existing KT amount. A mesio-distal and apical partial thickness dissection will be performed to release residual muscle tension and allow the passive apical displacement of the flap. The randomisation envelope will be then opened. In test group the VCMX will be gently shaped and secured under the flap with suture. Care will be applied to completely cover the xenograft. | Device: VCMX<br>* A flap will be raised and VCMX will be placed in order to increase the soft tissue volume<br>|
| Active Comparator: CTG<br>The control group patients will be treated by flap surgery with add of CTG. In the control group (APF) a CTG harvested from palate will be secured under the flap with suture. | Procedure: CTG<br>* A flap will be raised and a CTG will be harvested from the palate and placed in order to increase the soft tissue volume<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| GT | Changes in the gingival thickness (in mm) measured 1.0 mm coronal to the MGJ using an injection needle, perpendicular to the tissue surface, with a silicon stop over the gingival surface. | Immediately After Surgery | 
| GT | Changes in the gingival thickness (in mm) measured 1.0 mm coronal to the MGJ using an injection needle, perpendicular to the tissue surface, with a silicon stop over the gingival surface. | 1 week After surgery | 
| GT | Changes in the gingival thickness (in mm) measured 1.0 mm coronal to the MGJ using an injection needle, perpendicular to the tissue surface, with a silicon stop over the gingival surface. | 2 weeks After surgery | 
| GT | Changes in the gingival thickness (in mm) measured 1.0 mm coronal to the MGJ using an injection needle, perpendicular to the tissue surface, with a silicon stop over the gingival surface. | 4 weeks After surgery | 
| GT | Changes in the gingival thickness (in mm) measured 1.0 mm coronal to the MGJ using an injection needle, perpendicular to the tissue surface, with a silicon stop over the gingival surface. | 3 months After surgery | 
| GT | Changes in the gingival thickness (in mm) measured 1.0 mm coronal to the MGJ using an injection needle, perpendicular to the tissue surface, with a silicon stop over the gingival surface. | 6 months after surgery | 
| GT | Changes in the gingival thickness (in mm) measured 1.0 mm coronal to the MGJ using an injection needle, perpendicular to the tissue surface, with a silicon stop over the gingival surface. | 12 months after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| PROMs | After explanation of the post-operative instructions patients will be given an evaluation questionnaire. Patient discomfort during procedure (from 0 to 10) and the overall judgment about the self-perception of procedure difficulty will be assed using a Visual Analogue Scale (VAS- (from 0 to 100)) | Immediately After Surgery | 
| PROMs | After explanation of the post-operative instructions patients will be given an evaluation questionnaire. Patient discomfort during procedure (from 0 to 10) and the overall judgment about the self-perception of procedure difficulty will be assed using a Visual Analogue Scale (VAS- (from 0 to 100) | 1 week After surgery | 
| PROMs | After explanation of the post-operative instructions patients will be given an evaluation questionnaire. Patient discomfort during procedure (from 0 to 10) and the overall judgment about the self-perception of procedure difficulty will be assed using a Visual Analogue Scale (VAS- (from 0 to 100) | 2 weeks After surgery | 
| PROMs | After explanation of the post-operative instructions patients will be given an evaluation questionnaire. Patient discomfort during procedure (from 0 to 10) and the overall judgment about the self-perception of procedure difficulty will be assed using a Visual Analogue Scale (VAS- (from 0 to 100) | 4 weeks After surgery | 
| PROMs | After explanation of the post-operative instructions patients will be given an evaluation questionnaire. Patient discomfort during procedure (from 0 to 10) and the overall judgment about the self-perception of procedure difficulty will be assed using a Visual Analogue Scale (VAS- (from 0 to 100) | 3 months After surgery | 
| PROMs | After explanation of the post-operative instructions patients will be given an evaluation questionnaire. Patient discomfort during procedure (from 0 to 10) and the overall judgment about the self-perception of procedure difficulty will be assed using a Visual Analogue Scale (VAS- (from 0 to 100) | 6 months after surgery | 
| PROMs | After explanation of the post-operative instructions patients will be given an evaluation questionnaire. Patient discomfort during procedure (from 0 to 10) and the overall judgment about the self-perception of procedure difficulty will be assed using a Visual Analogue Scale (VAS- (from 0 to 100) | 12 months after surgery | 
| KT | The distance between muco-gingival junction, in mm, (MGJ) to the most coronal point of the ridge using a periodontal probe | At Baseline | 
| KT | The distance between muco-gingival junction, in mm, (MGJ) to the most coronal point of the ridge using a periodontal probe | 1 week After surgery | 
| KT | The distance between muco-gingival junction, in mm, (MGJ) to the most coronal point of the ridge using a periodontal probe | 2 weeks After surgery | 
| KT | The distance between muco-gingival junction, in mm, (MGJ) to the most coronal point of the ridge using a periodontal probe | 4 weeks After surgery | 
| KT | The distance between muco-gingival junction, in mm, (MGJ) to the most coronal point of the ridge using a periodontal probe | 3 months After surgery | 
| KT | The distance between muco-gingival junction, in mm, (MGJ) to the most coronal point of the ridge using a periodontal probe | 6 months after surgery | 
| KT | The distance between muco-gingival junction, in mm, (MGJ) to the most coronal point of the ridge using a periodontal probe | 12 months after surgery |