Different performance of devices used in case of patients undergoing dental cone beam computed tomography (CBCT) examinations as well as procedure itself may result in complex dose distribution within the patient [1]. At the moment, depending on publication, three dosimetric quantities (dose indices) are suggested to be used as representation of patient dose: CT dose index (CTDI) [2], CBCT dose indices (CBCTDI₁ and CBCTDI₂) or dose-area product (DAP) [1, 3].  

CBCT dose indices, CBCTDI₁ and CBCTDI₂ were proposed by the SEDENTEXCT project [1]. CBCTDI₁ is defined as average dose along the line were doses are measured and CBCTDI₂ by equation given on Figure 1 [1, 4]. CBCTDI₁ was proposed as suitable for all scanning geometries while CBCTDI₂ was proposed just for cases when centre of the FOV and centre of the phantom coincide and when 360^o of X-ray tube rotation is employed. [1, 4].

Since it was previously explained why CTDI should not be used as dose index in case of dental CBCT [1], the aim of study was to investigate DAP and CBCT dose indices and to propose one which should be used for establishing diagnostic reference levels (DRLs) in dental CBCT.