Hemostatic Gelatin Sponge Versus Collagen Matrix in Alveolar Ridge Preservation

Study Overview
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Brief Summary
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Patients in need of extraction of two teeth followed by implant replacement, with > 50% buccal bone present following tooth extraction and with 1 or 2 neighbouring teeth present, were invited to participate in an intra-subject RCT comparing hemostatic gelatin sponge to collagen matrix as socket seal in alveolar ridge preservation. The sample size calculation indicated 16 patients to be included per group. To compensate for dropouts, this number was increased to 20 patients per group. Coincidence (coin flip) determined which site is treated with the gelatine sponge and which with the collagen matrix. Teeth were extracted without flap elevation. When deemed necessary by the clinician, papillary incisions were made for minimal reflection, which enabled to place elevators without damaging soft tissues. Buccal soft tissues were never raised. Following wound debridement and rinsing, the alveolar socket was filled with collagen-enriched deproteinized bovine bone mineral (C-DBBM, Bio-Oss Collagen® 100 mg or 250 mg, Geistlich Pharma AG, Wolhusen, Switzerland) up to the level of the oral bone crest. Subsequently, a collagen matrix (Mucograft Seal®, Geistlich Pharma AG, Wolhusen, Switzerland) or gelatin spons (Spongostan Dental® 1x1x1 cm, Ethicon, Johnson & Johnson, New Brunswick, VS) was sutured on top with 4 to 6 single sutures (Seralon 6/0, Serag Weissner, Naila, Germany) to protect the underlying C-DBBM. Changes in soft tissue height at the buccal and oral aspect is the primary outcome. A small-field low-dose CBCT image was taken at T0 (immediately postop) and T3 (4 months). Those images were superimposed in specialized software (OnDemand3D, Cybermed Inc., Seoul, South-Korea). Changes in soft tissue height were calculated by subtracting soft tissue height at T3 from soft tissue height at T0. Secondary outcomes included wound healing and closure in the first three weeks, changes in hard and soft tissues and mucosal scarring after 4 months.

Official Title
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A Randomized Controlled Trial Comparing Hemostatic Gelatin Sponge to Collagen Matrix as Socket Seal in Alveolar Ridge Preservation

Conditions
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Changes in Soft Tissue Height

Intervention / Treatment
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* Device: test group: collagen matrix (Mucograft Seal®, Geistlich Pharma AG, Wolhusen, Switzerland)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: good oral hygiene (plaque score < 25%) 1 or 2 neighbouring teeth present in need for extraction of two teeth, followed by implant placement >50% bone present signed informed consent Exclusion Criteria: systematic diseases smoking history of periodontitis untreated caries lesions pregnancy

Ages Eligible for Study
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Minimum Age: 21 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
Interventional Model Description: Intra-subject RCT with 2 treatment arms (control group: collagen matrix; test group: hemostatic gelatine sponge). In every patient two teeth are extracted. Coincidence (coin flip) will determine which site is treated with the gelatine sponge and which with the collagen matrix.
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Control group: Collagen Matrix<br>collagen matrix: Mucograft Seal®, Geistlich Pharma AG, Wolhusen, Switzerland | Device: test group: collagen matrix (Mucograft Seal®, Geistlich Pharma AG, Wolhusen, Switzerland)<br>* Following tooth extraction and wound debridement, the alveolar socket was filled with collagen-enriched deproteinized bovine bone mineral (C-DBBM, Bio-Oss Collagen® 100 mg or 250 mg, Geistlich Pharma AG, Wolhusen, Switzerland) up to the level of the oral bone crest. Subsequently, a collagen matrix (Mucograft Seal®, Geistlich Pharma AG, Wolhusen, Switzerland) or gelatin spons (Spongostan Dental® 1x1x1 cm, Ethicon, Johnson & Johnson, New Brunswick, VS) was sutured on top with 4 to 6 single sutures (Seralon 6/0, Serag Weissner, Naila, Germany) to protect the underlying C-DBBM.<br>* Other names: control group: gelatin spons (Spongostan Dental® 1x1x1 cm, Ethicon, Johnson & Johnson, New Brunswick, VS);|
| Experimental: Test group: Hemostatic Gelatin Sponge<br>Hemostatic gelatin spons: Spongostan Dental® 1x1x1 cm, Ethicon, Johnson & Johnson, New Brunswick, VS | Device: test group: collagen matrix (Mucograft Seal®, Geistlich Pharma AG, Wolhusen, Switzerland)<br>* Following tooth extraction and wound debridement, the alveolar socket was filled with collagen-enriched deproteinized bovine bone mineral (C-DBBM, Bio-Oss Collagen® 100 mg or 250 mg, Geistlich Pharma AG, Wolhusen, Switzerland) up to the level of the oral bone crest. Subsequently, a collagen matrix (Mucograft Seal®, Geistlich Pharma AG, Wolhusen, Switzerland) or gelatin spons (Spongostan Dental® 1x1x1 cm, Ethicon, Johnson & Johnson, New Brunswick, VS) was sutured on top with 4 to 6 single sutures (Seralon 6/0, Serag Weissner, Naila, Germany) to protect the underlying C-DBBM.<br>* Other names: control group: gelatin spons (Spongostan Dental® 1x1x1 cm, Ethicon, Johnson & Johnson, New Brunswick, VS);|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in soft tissue height at the buccal and lingual aspect | A CBCT was taken at T0 (immediately post-op) and T3 (4 months). Since soft tissues were separated from hard tissues by using lip retractors and a backward position of the tongue, soft tissue height could be assessed on CBCT images. Changes in soft tissue height were calculated by subtracting soft tissue height at T3 from soft tissue height at T0. | T0 (immediately post-op) and T3 (4 months) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Wound healing | Socket wound healing score (SWHS). SWHS was assessed on the basis of occlusal clinical pictures and results in the following scores: 0 = Wound covered with keratinized gingiva, pink tissue color, no bleeding, continuous with healthy tissue; 1 = Socket filled with organized granulation tissue, no bleeding, collapsed to a depth of 0 - 2 mm from the buccal gingival margin; 2 = Socket filled with organized granulation tissue, ¼ to ½ of the wound showing red tissue color, no bleeding, collapsed to a depth of 2 - 4 mm from the buccal gingival margin; 3 = Socket filled with unorganized granulation tissue, more than ½ of the wound showing red tissue color, bleeding, no evidence of acute infection; 4 = Socket is filled with foreign material (food, etc.) and shows signs of alveolitis. The higher the score, the worser the outcome. | T1 (1 week), T2 (3 weeks) and T3 (4 months) | 
| Wound dimension | Bucco-lingual and mesio-distal wound dimensions were registered with a periodontal probe to the nearest 0.5 mm at T0 (immediately postop), T1 (1 week) and T3 (4 months). | T0 (immediately post-op), T1 (1 week) and T3 (4 months) | 
| Changes in buccal soft tissue profile | An intra-oral scan was taken at T0 (immediately postop) and T3 (4 months). The obtained digital surface models in STL format were imported into designated software to analyze profilometric changes. A study-relevant area of interest (AOI) at the buccal aspect was selected for each site. The AOI varied between sites due to individual anatomic differences but was kept constant in each site across timepoints. Digital surface models were superimposing using the best-fit algorithm at the unchanged adjacent tooth surfaces. A mean volumetric change (mm3) within the AOI for each site from T0 to T3 was calculated by the software and divided by the AOI resulting in a mean change in buccal soft tissue profile. Details on the method can be found in an earlier paper (Eeckhout et al., 2020). | T0 (immediately post-op) and T3 (4 months) | 
| Mucosal scarring | The Mucosal Scarring Index (MSI) (Wessels et al., 2019) was registered on the basis of frontal and occlusal clinical pictures. The MSI results in a score from 0 (no scar) to 10 (most extreme scar). The higher the score, the worser the outcome. | T3 (4 months) |