Tomographic and Histologic Assessment on the Influence of the Use of a Collagen Membrane to Protect the Antrostomy After Maxillary Sinus Floor Augmentation.

Study Overview
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Brief Summary
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the aim of the present study was to evaluate the dimensional variation and osseointegration of mini-implants at augmented sinus with the antrostomy left unprotected or protected with a collagen membrane.

Detailed Description
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The Schneiderian mucosa will be elevated and the created space will be filled with a natural bovine bone grafting material (Cerabone® 1-2 mm, Botiss Biomaterials GmbH). In ten patients randomly selected (control sties), a native collagen membrane made of porcine dermis (Collprotect®, Botiss Biomaterials GmbH) will be placed on the antrostomy. In another ten patients of the test group, the antrostomy will be left without the membrane. The flaps will be sutured and anti-inflammatory drugs and antibiotics will be administrated to the patients. The sutures will be removed after 7 days. After 6 months of healing, two mini-implants with different surface will be installed and retrieved after further 3 months for histomorphometric evaluations. CBCTs will be taken for all patients before surgery (T0), after 1 week from sinus floor augmentation (T1) and after 9 months of healing (T2) and evaluation of dimensional variations over time of soft and hard tissues will be performed.

Official Title
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Cone Beam Computed Tomography and Histomorphometric Assessments on the Influence a Collagen Membrane Placed on the Antrostomy After Maxillary Sinus Floor Augmentation. A Randomized Clinical Trial.

Conditions
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Alveolar Bone Loss, Alveolar Bone Resorption

Intervention / Treatment
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* Procedure: Maxillary sinus augmentation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Presence of an edentulous atrophic zone in the posterior segment of the maxilla Height of the sinus floor ≤4 mm. Desiring a prosthetic restoration of the zone using a fix prosthesis supported by implants ≥ 21 years of age Good general health No contraindication for oral surgical procedures Not being pregnant. Exclusion Criteria:The patients will be excluded if they present: A systemic disordered. Had a chemotherapic or radiotherapeutic treatment. Are smokers >10 cigarettes per day Have an acute or a chronic sinusitis. Had a previous bone augmentation procedures in the zone of interest.

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

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: test and control group
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: test site<br>The space obtained underneath the sinus mucosa will be filled with the xenograft without protecting the antrostomy with a collagen membrane in the test sites. Bone to implant contact was measured at the turned and machined surface. | Procedure: Maxillary sinus augmentation<br>* Surgical technique for increasing the vertical bone height of the posterior maxilla an antrostomy of about 5 mm in height and 10 mm long will be prepared using a diamond insert mounted on a sonic-air surgical instrument. The Schneiderian membrane will be elevated and clinical measurements will be performed using an UNC 15 probe. The space obtained underneath the sinus mucosa will be filled with the xenograft and a resorbable collagen membrane will be placed to cover the antrostomy only at the randomly selected control sites.<br>* Other names: maxillary sinus lift, maxillary sinus elevation;|
| Active Comparator: control site<br>The space obtained underneath the sinus mucosa will be filled with the xenograft and a resorbable collagen membrane will be placed to cover the antrostomy only at the randomly selected control sites. Bone to implant contact was measured at the turned and machined surface. | Procedure: Maxillary sinus augmentation<br>* Surgical technique for increasing the vertical bone height of the posterior maxilla an antrostomy of about 5 mm in height and 10 mm long will be prepared using a diamond insert mounted on a sonic-air surgical instrument. The Schneiderian membrane will be elevated and clinical measurements will be performed using an UNC 15 probe. The space obtained underneath the sinus mucosa will be filled with the xenograft and a resorbable collagen membrane will be placed to cover the antrostomy only at the randomly selected control sites.<br>* Other names: maxillary sinus lift, maxillary sinus elevation;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changing in height of the elevated zone. | will be assessed in the medial, middle and lateral regions of the elevated zone using the cone beam computerized tomographies | The CBCTs will be taken before surgery (T0) and 1-week (T1) and 9 months (T2) after surgery | 
| Bone-to-implant contact between the different surfaces and between membrane / no membrane groups | Measurements of new bone formation will be assessed on the histological images taken from the slides and performed between the most coronal bone contact to the surface and the apex of the mini-implant. Comparisons among test and control (without or with a collagen membrane of the access window) and between the two different surface conformations will be performed | three months of healing | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changing in area of the elevated zone | The area will be delineated by the sinus bone walls and the sinus mucosa. The changes will be evaluated on the cone beam computerized tomographies (CBCTs) taken in various periods. | The CBCTs will be taken before surgery (T0) and 1-week (T1) and 9 months (T2) after surgery | 
| Bone density | Measurements of new bone formation will be assessed on the histological images taken from the slides and performed between the most coronal bone contact to the surface and the apex of the mini-implant. Comparisons among test and control (without or with a collagen membrane of the access window) and between the two different surface conformations will be performed. | three months of healing | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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biomaterial, antrostomy, Maxillary sinus augmentation, collagen membrane