Dental Implant Study Comparing Two Types of Metals Used for Dental Implants
Condition: Tooth Replacement
Study type: Interventional

Summary: 
      The purpose of this research study is to compare the healing differences of two metals
      (trabecular vs. standard titanium) that are used for dental implants. In addition;
      investigators will be examine these differences in the gene expression profiles in subjects
      with three conditions associated with delayed healing: diabetes and osteoporosis.

      The study will last at least 11 weeks consisting of 6 appointments. All visits will be
      carried out at the GO Health Center within the UNC School of Dentistry. Visits will last
      between 30 minutes to 3 hours depending on the particular visit.

      The visits will consist of: Obtaining consent, doing a health history, measuring vital signs,
      doing dental exams of the teeth and gums, collecting samples of saliva dental radiographs
      (X-rays), a teeth cleaning, having 4 temporary mini test cylinders placed in areas of the
      lower jaw where teeth are missing and implant surgery to place up to four permanent implants.
    

Detailed description: 
      The plan is to recruit subjects into 3 groups: 1) systemically healthy, 2) subjects with
      diabetes (ADA classification determined by glycosylated hemoglobin A1C levels), and 3)
      subjects with osteoporosis (limited to those on either no drugs or oral bisphosphonates
      only). All subjects recruited will have already been approved and treatment planned for
      implant placement by non-study personnel to avoid any potential conflict of interest. All
      subjects will have mandibular radiographs that show edentulous ridge areas that provide
      enough alveolar ridge space to place two test cylinders (each approximately 2.9-3 x 5mm) on
      each side of the mandible. One side will have two titanium test cylinders and the
      contralateral side will have two trabecular metal test cylinders. After placement of these 4
      test cylinders, one will be removed contra laterally from each side at weeks 2 and 4 of
      healing. Thus, by 28 days all test cylinders will be removed.

      It has been our experience that each cylinder after removal will contain enough cells to
      provide approximately 10-20μg of total RNA. This quantity of total RNA is sufficient to run
      an Affymetrix chip and have enough mRNA for PCR confirmation. Sampling at 3 days after
      placement is too soon, as it does not provide adequate mRNA for the analysis, since the clot
      has not become remodeled or adequately organized to be cellular. Thus, by 1 week organization
      of the osseous healing will have begun and at week 2 it will be beginning to mature. The week
      2 sampling time point) will provide us with early molecular kinetics of the healing response
      to compare the two metal surfaces and the differences in gene expression that may be
      associated with diabetes and osteoporosis. At weeks 2 and 4 the test cylinders will be
      removed using a 5.0 mm diameter tissue punch and a 5 mm trephine drill. Investigators will
      select 18 random patients (6 subjects per group) to provide (two test cylinders for each, 36
      samples) for histology. Investigators will use the trephine drill to remove the 4 week test
      cylinders in all 3 groups of subjects. In all cases, a subject is eligible for this study by
      being pretreatment planned to receive a permanent implant bilaterally, which will be placed
      at donor sites. According to the participant's individual treatment plan, after test
      cylinders are removed, each site will receive an implant using either a standard 4.1 or 4.7
      mm tapered screw vent design implant. The removed test cylinders will be briefly rinsed in
      saline and prepared chair side for either mRNA extraction or for histology.
    

Intervention name(s): Zimmer Trabecular Metal Test Cylinder; Zimmer Titanium Test Cylinder
Intervention type(s): Device; Device
Intervention description(s): For all subjects 2 titanium and 2 trabecular 2.9-3.0 mm x 5 mm test cylinders will be implanted in alveolar bone. One of each type will be removed at 2 weeks. The remaining two will be removed at 4 weeks.; For all subjects 2 titanium and 2 trabecular 2.9-3.0 mm x 5 mm test cylinders will be implanted in alveolar bone. One of each type will be removed at 2 weeks. The remaining two will be removed at 4 weeks.
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Dental; Implant; UNC Dental School; Trabecular Metal; Titanium; Healthy Volunteers; Diabetic; Osteopenic; Bone Inductive Properties; Osseous Healing; GO Health; Offenbacher; Zimmer Dental, Inc.