A Volumetric Analysis of Soft and Hard Tissue Healing for Ridge Preservation and Socket Seal After Tooth Extraction

This study will be a randomized clinical trial involving a total of 24 subjects. The investigators propose to recruit subjects into 2 groups: 1) Extraction treated with xenograft bone substitute (BioOss Collagen®) + collagen dressing (HeliPlug®), 2) Extraction treated with xenograft bone substitute (BioOss Collagen®) + 3D-collagen matrix (Mucograft Seal®). All subjects recruited will have already been approved and treatment planned for extraction + implant placement by non-study personnel to avoid any potential conflict of interest. All subjects will have radiographs that show the tooth planned for extraction. Each subject will be eligible for only 1 tooth extraction + dental implant rehabilitation. After tooth extraction, subjects will receive a standard site preservation therapy consisted with xenograft bone substitute + collagen dressing or the alternative site preservation therapy consisted with xenograft bone substitute + 3D-collagen matrix. After the conventional 6-month healing period, subjects will receive a dental implant in the previous extracted site. During the dental implant procedure, a 2x5mm bone core biopsy + a 2mm gingival biopsy will be obtained from the implant site. Biopsy samples will be stored for future histological and histochemical analysis. After dental implant placement, all subjects will receive a healing abutment for soft tissue healing prior to implant restoration.

During the 6-month healing time after tooth extraction and site preservation therapy, subjects will return at week-1, week-2, week-4, month-3, and month-6 for intra-oral scanning for soft tissue volumetric acquirement. Subjects will receive a Cone beam computed tomography (CBCT) prior to extraction for the baseline hard-tissue volume measurement and appropriate extraction planning and at 6-month post-extraction for volumetric measurement and appropriate implant treatment planning.

Hard tissue analysis will be performed to compare linear ridge remodeling (baseline vs. 6-month healing). CBCT images will be analyzed by non-contact reverse engineering system. Soft tissue volumetric analysis will be performed to compare the soft tissue healing between BioOss Collagen + Mucograft Seal and BioOss Collagen + Collagen Dressing. Images captured with an intra-oral scanner collected at baseline, week-1, -2, -4, month-3, and month-6.


Eligibility Criteria:
Inclusion Criteria:

* Subjects must be adult males or females age 18 to 80 years (inclusive).
* Subjects must be able and willing to follow study procedures and instructions in English.
* Subjects must have read, understood and signed an informed consent form in English.
* Subjects must have a maxillary premolar, canine, lateral incisor, or central incisor with a restorative or periodontal hopeless prognosis (Kwok and Caton 2007), in which an implant is indicated without any sinus lift required.
* Subjects undergoing implant placement should be in adequate periodontal health prior to implant placement. This includes having probing depth ≤ 4 mm for all remaining teeth at the same quadrant of the proposed implant placement. Patients with periodontal probing sites with probing depths of up to 5 mm may also be included if bleeding on probing in these sites is absent. Each subject should be considered to be periodontally stable prior to the implant surgery.

Exclusion Criteria:

* Individuals who have a chronic disease with oral manifestations.
* Individuals who exhibit gross oral pathology.
* The use of either antibiotics or chronic use (more than 7 days) of NSAIDs within 1 month prior to screening examination.
* Individuals that require antibiotic prophylaxis prior to dental treatment.
* Chronic treatment (i.e. two weeks or more) with any medication known to affect periodontal status (e.g. phenytoin, calcium antagonists, cyclosporine, Coumadin) within 1 month prior to screening examination.
* Uncontrolled diabetes mellitus (HbA1c \>7) within 3 months prior to screening examination.
* Individual with uncontrolled parafunctional habits, such as clenching and bruxing on objects, that could adversely impact implant survival.
* Individuals with a history of intravenous bisphosphonates.
* Individuals with active infectious diseases such as hepatitis, HIV or tuberculosis.
* Current cigarette smokers.
* Individuals who are known to be pregnant, breastfeeding or planning to become pregnant within 6 months.
* Individuals with blood disorders (hemophilia) and /or currently taking anticoagulant medications, such as heparin, warfarin, or clopidogrel.
* Individuals receiving any therapy known to affect healing, such as high dose corticosteroids, radiation therapy or chemotherapy.
* Individuals allergic to topical or local anesthesia.
* Individuals who require maxillary sinus augmentation prior to dental implant therapy.
* Individuals with dehisced, fenestrated, or fractured labial/buccal alveolar bone plate determined after baseline CBCT or after tooth extraction where more than 50% of the buccal bone height is not present. In this case, if the surgeon determines that guided bone regeneration (bone graft and membrane) is needed to repair the defect, it will be done at no cost to the subject, but the subject will be excluded from the study protocol.