A Comparison Between Primary and Secondary Flap Coverage in Extraction Sites: A Pilot Study

Study Overview
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Brief Summary
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This study is being conducted to compare the outcomes of two separate surgical techniques used in tooth extraction and ridge preservation. Ridge preservation is done to potentially minimize the amount of bone loss that occurs between the tooth extraction and implant or bridge placement, as compared to leaving the extraction site empty. There are two techniques that are commonly used for these procedures, either to close the surgical site of the extracted tooth with sutures (closed flap technique) or to leave the extraction site open to heal naturally (open flap technique). In the open flap technique there will be sutures used to secure and hold down the material used to cover the wound, called a non-resorbable membrane. The flaps will remain in their natural position, the site will fill up naturally with new tissue from the bottom up and then close itself in from the sides. The investigators want to see which technique offers better healing and reduces bone loss.

Detailed Description
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Study design will be a single center, randomized controlled trial, split mouth designed study, to compare the bone dimensional changes following extraction and ridge preservation in surgical techniques that leave the flap open and closed. The primary aim of this study is to evaluate the bone dimensional changes following extraction and ridge preservation with primary coverage (closed flap technique) in comparison to secondary intention (open flap technique). The investigators hypothesize that the closed flap technique will have more potential to maintain vertical bone height when compared with the open flap technique, due to less susceptibility from infection and inflammation. Secondary aim is to evaluate patients' self-report of postoperative discomfort. The investigators hypothesize that open flap technique will have less post-operative pain/discomfort due to less flap dissection and elevation when compared to closed flaps. Tertiary aim is to have a histomorphometric examination and to assess the formation of new bone. The investigators hypothesize that better bone volume percentage will be observed in closed flap technique when compared to open flap technique. The primary outcome is the mean difference in alveolar bone height change between groups.

Official Title
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A Comparison Between Primary and Secondary Flap Coverage in Extraction Sites: A Pilot Study

Conditions
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Loss of Teeth Due to Extraction

Intervention / Treatment
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* Device: Cytoplast® TXT-200
* Device: MinerOss® Cortical and Cancellous Chips (FDBA)
* Procedure: Open Flap Technique
* Procedure: Closed Flap Technique


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient who is treatment planned at Tufts University School of Dental Medicine (TUSDM) for extraction and future implant placement and meet all medical and dental requirements of the TUSDM periodontology clinic for periodontal surgery (e.g., subjects with no diseases or medication allergies contraindicating periodontal surgery). Patient must have bilateral extraction (canine to molar) sites of teeth located on the same arch (e.g. upper right and upper left) treatment planned for future implant placement at TUSDM. The number of teeth planned for extraction (either one or two adjacent) and ridge preservation should match the same number of teeth (either one or two adjacent) from the contra-lateral side on the same arch. Presence of at least 3 intact bony walls and at least half of the fourth bony wall at each site as determined by bone sounding at Visit 1. Exclusion Criteria: Have any known disease that interferes with periodontal surgery and would not allow the patient to be treatment planned for the procedures in the TUSDM periodontology clinic (e.g., severe anemia, low white blood cell count, bleeding or coagulation disorder, uncontrolled hypertension (150/90), recent myocardial infarction (within 6 months of enrollment), diabetes (HbA1C ≥7%), HIV/AIDS (self-reported), history of or currently undergoing head and neck radiation, history of or currently taking bisphosphonates). Subject who has a disease or condition that may affect hard and soft tissue healing (e.g., previous or current head and neck radiation therapy, long term steroid use defined as more than two weeks in the past two years). Subject who has diseases that affect bone metabolism (e.g., osteoporosis, osteopenia). Pregnancy (self-reported) Current Smokers Extraction socket with > 50% bone loss on the buccal or lingual/palatal bone as determined by bone sounding at Visit 1. Allergic to gentamycin, povidone-iodine, or surfactants as trace amounts may be contained in the MinerOss®

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: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Closed Flap Technique<br>Healing by primary intention: Extraction and ridge preservation, utilizing non-resorbable membrane (Cytoplast® TXT-200 ) and freeze dried bone allograft (MinerOss® Cortical and Cancellous Chips (FDBA)), with flaps in primary coverage. | Device: Cytoplast® TXT-200<br>* Non-resorbable membrane<br>Device: MinerOss® Cortical and Cancellous Chips (FDBA)<br>* Mixture of allograft mineralized cortical and cancellous chips<br>Procedure: Closed Flap Technique<br>* After extraction, the socket wound is closed by primary closure<br>|
| Active Comparator: Open Flap Technique<br>Healing by secondary intention: Extraction and ridge preservation, utilizing non-resorbable membrane (Cytoplast® TXT-200) and freeze dried bone allograft (MinerOss® Cortical and Cancellous Chips (FDBA)), with flaps in position for healing by secondary intention. | Device: Cytoplast® TXT-200<br>* Non-resorbable membrane<br>Device: MinerOss® Cortical and Cancellous Chips (FDBA)<br>* Mixture of allograft mineralized cortical and cancellous chips<br>Procedure: Open Flap Technique<br>* After extraction, the socket wound is left open to heal by secondary intention<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean Difference in Alveolar Bone Height Change | Models/casts will be made in stone using the impressions. A stent will be made to measure the height and width of the alveolar ridge. Ridge height will be measured before tooth extraction, and 3-5 months after ridge preservation. | < 6 months post extraction and ridge preservation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Post-operative Pain/Discomfort | Subjects will be asked to rate their pain/discomfort on a visual analog scale (VAS) questionnaire (scores on a scale of 0-10, 10 to be the worst) | Up to 16 days post extraction and ridge preservation | 
| Percentage New Bone Formation | Histomorphometric analysis of bone core biopsy to determine percent new bone formation | Up to 6 months post extraction and ridge preservation |