Ridge Preservation in Molar Sites Comparing Xenograft Versus Mineralized Freeze-dried Bone Allograft

Study Overview
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Brief Summary
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The objectives of the present investigation are; to compare the dimensional changes and the histological composition after the use of an allograft or xenograft and a resorbable membrane in ridge preservation in molar sites, to evaluate the influence of bone plates thickness on dimensional changes and the effectiveness of ridge preservation in limiting the need of sinus elevation.

Detailed Description
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Twenty-four patients in need of maxillary or mandibular molar extraction and subsequent implant placement were included and randomly assigned to a group; allograft or xenograft, plus a collagen membrane. Cone Beam Computed Tomographies were obtained after molar extraction and after five months. A bone sample was harvested at the time of implant placement and analysed by histomorphometry.

Official Title
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Ridge Preservation in Molar Sites Comparing Xenograft Versus Mineralized Freeze-dried Bone Allograft: a Randomized Clinical Trial

Conditions
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Alveolar Ridge Preservation

Intervention / Treatment
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* Procedure: Ridge preservation
* Device: bone graft plus a collagen membrane


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients, over 18 years old. In need of removal of a maxillary or mandibular molar first or second molar. The molars to be extracted had to be bordered by at least one tooth. The molars had to have a presence of > 2 mm of keratinized gingiva and three intact bony walls. A dehiscence on the fourth wall, if any, had to be equal or less than 2 mm in height. Only one extraction per patient was accepted. Exclusion Criteria: Acute periodontal or periapical infection. Pregnancy or lactancy. Smokers of more than 10 cigarettes per day. Previous adverse reactions to the biomaterials used in the study. Metabolic diseases affecting the mechanism of bone remodelling. Medications or treatments taken in the last twelve months and known to affect bone turnover. Patients with poor plaque control -more than 20% (O'Leary, Drake, Naylor, 1972). Patients with absence of periodontal health maintenance or postoperative recommendations compliance.

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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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
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: xenograft and a collagen membrane<br> | Procedure: Ridge preservation<br>* Ridge preservation in molar areas using a xenograft or an allograft in combination with a barrier collagen membrane<br>Device: bone graft plus a collagen membrane<br> <br> |
| Active Comparator: allograft and a collagen membrane<br> | Procedure: Ridge preservation<br>* Ridge preservation in molar areas using a xenograft or an allograft in combination with a barrier collagen membrane<br>Device: bone graft plus a collagen membrane<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluation of ridge dimensional changes following ridge preservation in molar sites comparing the use of freeze dried bone allograft (FDBA) or xenograft (DBBM), and a resorbable membrane. | To evaluate dimensional changes, the initial (CBCT1) and 5 months (CBCT2) CBCT images were processed and superimposed with the use of a specialized software image Simplant® O&O (Denstply Sirona, Charlotte, NC, USA). Measurements were expressed in millimeters (mm) and percentages showing changes in ridge width at 1mm, 3mm and 5mm from the bone crest. The height of the buccal, and lingual bone crest was assessed, as well as the heigh in the central are of the socket. | 5 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluate the influence of buccal or lingual bone thickness on bone ridge changes | The width of the buccal and lingual bone plates was evaluated, by CBCT analysis, at 1mm, 3mm and 5mm to evaluate any correlation with bone dimensional changes after 5 months. Data was expressed in milimeters. | 5 months | 
| Evaluate the histologic composition of the regenerated areas after the use of freeze dried bone allograft (FDBA) or xenograft (DBBM), and a resorbable membrane. | The histomorphometric analysis was performed by the use of a specific software image (Image J®, Image Processing and Analysis in Java) and the areas occupied by vital bone (VB), non-mineralized connective tissue (NMCT) and graft particles (GP) were evaluated. The analysis of each tissue volume was expressed in percentages (%) | 5 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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alveolar ridge preservation, molars, xenograft, allograft