Stability of voxel values from cone‐beam computed tomography for dental use in evaluating bone mineral content

<jats:title>Abstract</jats:title><jats:sec><jats:title>Objectives</jats:title><jats:p>The objective of this study was to investigate the stability of voxel values from cone‐beam <jats:styled-content style="fixed-case">CT</jats:styled-content> (<jats:styled-content style="fixed-case">CBCT</jats:styled-content>) using a flat panel detector in changing surrounding circumstances mimicking clinical situations.</jats:p></jats:sec><jats:sec><jats:title>Materials and methods</jats:title><jats:p>Seven hydroxyapatite (<jats:styled-content style="fixed-case">HA</jats:styled-content>) rods (0, 40, 80, 120, 160, 199, and 239 mg Ca/cm<jats:sup>3</jats:sup>) were set in a 16 cm diameter water phantom and scanned with <jats:styled-content style="fixed-case">CBCT</jats:styled-content> (FineCube) and also with multislice <jats:styled-content style="fixed-case">CT</jats:styled-content> (<jats:styled-content style="fixed-case">MSCT</jats:styled-content>) used as reference. The voxel values from <jats:styled-content style="fixed-case">CBCT</jats:styled-content> were measured by the obtained images with OsiriX software (<jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.osirix-viewer.com">http://www.osirix-viewer.com</jats:ext-link>), and compared with the <jats:styled-content style="fixed-case">CT</jats:styled-content> numbers from <jats:styled-content style="fixed-case">MSCT</jats:styled-content>. We examined the correlation between the voxel values and the <jats:styled-content style="fixed-case">HA</jats:styled-content> contents, the variance of voxel values, and the influence of changing surrounding circumstances on the voxel values.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>The voxel values from <jats:styled-content style="fixed-case">CBCT</jats:styled-content> were different from the <jats:styled-content style="fixed-case">CT</jats:styled-content> numbers from <jats:styled-content style="fixed-case">MSCT</jats:styled-content>, but there was a linear Pearson correlation between the voxel values and the <jats:styled-content style="fixed-case">HA</jats:styled-content> contents. The voxel values were greatly influenced when the samples were scanned surrounded in air. However, the voxel values were not affected significantly in the existence of materials simulating oral hard tissues and/or a metal core post.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>There was a linear correlation between the voxel values of <jats:styled-content style="fixed-case">CBCT</jats:styled-content> and the contents of <jats:styled-content style="fixed-case">HA</jats:styled-content> rod samples. Our study indicated that it might be possible to evaluate bone mineral content<jats:styled-content style="fixed-case">(BMC)</jats:styled-content> from the voxel values of <jats:styled-content style="fixed-case">CBCT</jats:styled-content> for dental implant treatment.</jats:p></jats:sec>