The Influence of Bone Allograft Particle Sizes on the Quantity and Quality of New Bone Formation in Grafted Extraction Sockets and Edentulous Ridges
Condition: Alveolar Ridge Augmentation; Alveolar Ridge Preservation
Study type: Interventional

Summary: 
      This study will evaluate the effect of allograft bone particle size on the bone quantity and
      quality following socket grafting and lateral ridge augmentation in preparation for
      endosseous implant placement.

      Pre (baseline)- and post-grafting (3 months for sockets and 6 months for edentulous ridges)
      clinical as well as 2- and 3-dimensional radiographic measurements will be used to evaluate
      the differences between sites grafted with small vs. large particle sized bone allografts.

      Histological analysis will be performed at time of surgical re-entry of grafted sites to
      place the dental implants, and assessed for differences in new bone formation between the 2
      types of grafts.
    

Detailed description: 
      This study is a prospective, two-arm, randomized trial that will evaluate and compare the
      bone healing following ridge preservation of extraction sockets (RP, Arms 1 and 2) or lateral
      ridge augmentation of edentulous sites (RA, Arms 3 and 4) using either small particle (SP) or
      large particle (LP) mineralized cortico-cancellous bone allografts in a total of 48 patients
      (12 in each arm).

      Study approval was obtained from the university's institutional review board. Qualifying
      participants and defects are randomized following a computerized permutation block to receive
      either LP or SP allografts on day of surgery. In the RP arms, tooth extraction is performed
      with a flapless minimally invasive technique, followed by socket grafting with a randomized
      graft covered with a collagen dressing and sutures. In the RA arms, lateral ridge
      augmentation is conducted utilizing a randomized bone graft covered by a collagen membrane
      fixated with tacks.

      The mineralized cortico-cancellous bone allografts utilized in this study were all obtained
      from the same donor, lot and tissue bank to account for variation in age, race, gender and
      related healing potential of different graft sources.

      In the RP arm, bone core biopsies will be harvested at time of implant placement 3 months
      following socket grafting, whereas similar biopsies will be obtained at 6 months following
      lateral ridge augmentation in the RA group. These 2x2x6 mm bone cores will then undergo
      histological and histomorphometrical analyses to determine qualitative and quantitative
      healing differences between LP and SP in all study arms.

      Clinical measurements are gathered at 2 time points (grating and implant placement) at all
      defects and will be compared for differences.

      Cone beam computed tomography (CBCT) initial scans are conducted immediately following socket
      grafting (RP arms) and prior to ridge augmentation (RA arms) and second scans obtained prior
      to implant placement (all RP and RA arms). Virtual implant planning software (coDiagnostiX)
      will be utilized to assess and compare the 2- and 3-dimensional changes for all defects.
    

Intervention name(s): Socket Grafting with small particle allograft; Socket Grafting with large particle allograft; Lateral ridge augmentation with small particle allograft; Lateral ridge augmentation with large particle allograft
Intervention type(s): Device; Device; Device; Device
Intervention description(s): Small Particle Bone Allograft of 0.25-1.0 mm placed in extraction socket; Large Particle Bone Allograft of 1.0-2.0 mm placed in extraction socket; Small Particle Bone Allograft of 0.25-1.0 mm used in lateral ridge augmentation (Guided Bone Regeneration) and covered with a collagen membrane; Large Particle Bone Allograft of 1.0-2.0 mm used in lateral ridge augmentation (Guided Bone Regeneration) and covered with a collagen membrane
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Bone allograft; Particle size; Ridge preservation; Ridge augmentation; Socket grafting; Histology; New bone