Influence of scan setting selections on root canal visibility with cone beam CT

Objectives: The aim of this study was to assess the influence of scan setting selection, including field of view (FOV) ranging from small to large, number of projections and scan modes on the visibility of the root canal with cone beam CT (CBCT). Methods: One human mandible cadaver was scanned with CBCT (Accuitomo 170; J Morita MPG Corp., Kyoto, Japan) using six different FOVs (4 x 4 cm, 6 x 6 cm, 8 x 8 cm, 10 x 10 cm, 14 x 10 cm and 17 x 12 cm) with either 360 or 180 projections in standard and high resolution. The right canine was selected for evaluation. Ten observers independently assessed the visibility of the canal space and overall image quality on a five-point scale. Results: The results indicate that both selections of FOV and number of projections have significant influence on root canal visibility (p = 0.0001), whereas scan mode, whether standard or high resolution, was less relevant (p = 0.34). Conclusions: The smallest FOV available should always be used for endodontic applications, and it is not recommended to reduce the number of projections to 180. Using the standard scan mode instead of high resolution does not negatively influence the visibility of the root canal space and is therefore recommended. Dentomaxillofacial Radiology (2012) 41, 645-648. doi: 10.1259/dmfr/27670911