Cone-beam computed tomography density measurement repeatability in Hounsfield units: a preliminary study

Introduction
Dental implants are the treatment of choice for patients, who are either partially or fully edentulous. Bone quantity and quality at the surgical site are key factors in an implant success.

Objectives
To investigate the possibility of performing density measurement with Hounsfield units (HU) using cone-beam computed tomography (CBCT) in different types of materials.

Material and methods
The physical densities of 3 blocks (3 × 3 × 5 cm) made of 5 different materials (pine, beech, plaster, acrylic, and wax) were calculated. A VistaVoxS 3D CBCT device was used to scan each block using the following acquisition protocol: 5 × 5 field-of-view, 98 kVp, 11 mAs, and 0.08 voxel size. The resulting 15 CBCT scans after acquisitions were imported to AIS3DAPP 5.0 software. A virtual implant (16 mm × 5.2 mm) was centered in each block’s image, and bone density tool available in the software was used to measure HU with the virtual implant’s thirds. For each implant, mean HU values of the most anterior, posterior, left, and right sides were measured.

Results
In general, each material produced different mean HU values. Plaster produced the highest values (2,160.9), followed by acrylic (126.39), wax (–170.65), beech (–655.78), and pine (90.12)

Conclusions
CBCT HU were repeatable and higher in the high-density material studied. The bone density tool demonstrated to be useful and reproducible.