Vol.:(0123456789) 1 3 Oral Radiology https://doi.org/10.1007/s11282-018-0336-x ORIGINAL ARTICLE Comparison of cone-beam computed tomography with bitewing radiography for detection of periodontal bone loss and assessment of eﬀects of diﬀerent voxel resolutions: an in vitro study Hayriye Cetmili 1 · Melek Tassoker 1 · Sevgi Sener 1 Received: 23 March 2018 / Accepted: 28 April 2018 © Japanese Society for Oral and Maxillofacial Radiology and Springer Nature Singapore Pte Ltd. 2018 Abstract Objective The aim of the study was to compare intraoral radiographs and CBCT images for detection of horizontal peri- odontal bone loss, and to investigate the diagnostic eﬀect of diﬀerent voxel resolutions in CBCT imaging. Methods A total of 240 sites with horizontal bone loss were measured on the buccal, lingual, mesial, and distal surfaces of 60 posterior teeth in four maxillary and six mandibular bones obtained from cadavers (dry skulls). Direct measurements on the dry skulls were accepted as the gold standard values. Measurements on CBCT images at two diﬀerent voxel resolutions (0.250 and 0.160 mm 3 ) and intraoral bitewing radiographs were compared with one another and with the gold standard values. Results The measurements on the CBCT images at two voxel resolutions and bitewing radiographs did not diﬀer signiﬁcantly (p > 0.05) from the direct measurements on the dry skulls. No signiﬁcant diﬀerence was found between the bitewing radio- graphs and CBCT images for measurements in the mesial and distal regions (p > 0.05). There was no signiﬁcant diﬀerence between the measurements on the buccal and lingual surfaces at the two diﬀerent voxel resolutions (p > 0.05). Conclusions CBCT scans are recommended for evaluation of buccal and lingual bone loss to avoid intraoral radiographs that exceed routine examination of interproximal alveolar bone loss. Furthermore, instead of basing the voxel size on the required CBCT scans, it is recommended to select the smallest possible ﬁeld of view to reduce the dose of radiation. Keywords CBCT · Voxel · Periodontal bone loss · Bitewing radiography Introduction Radiographic imaging methods, which are most commonly used for clinical diagnosis and treatment outcome evalua- tion in periodontal disease [1], are crucial for the diagnosis and prognosis of such diseases [2, 3]. Through maxillofa- cial imaging, information on general and local alveolar bone levels, factors causing plaque involvement, caries, furcation defects, subgingival calculus, and additional pathologies can be obtained [4]. Commonly used radiographic meth- ods are bitewing, periapical, and panoramic radiographs [2]. However, these plane radiographs have some intrinsic disadvantages [3, 5, 6]. These disadvantages often limit the usefulness of such radiographs in periodontal disease. Furthermore, the assessments can only provide information about pathologies adjacent to the mesial and distal surfaces of the teeth in the parasagittal plane [4]. Recently, cone-beam computed tomography (CBCT) has been used as an alternative method in dentistry ﬁelds, including periodontology, to overcome the disadvantages of plane radiography for evaluation of head and neck structures [7, 8]. CBCT provides multiplanar imaging in the axial, sagittal, and frontal planes. Furthermore, reconstructed panoramic images can be obtained without distortion and magniﬁcation [9]. Therefore, CBCT allows evaluation of the target area in three dimensions with the advantages of high accuracy, high resolution, and low cost compared with conventional tomography [10]. The voxel, the smallest unit of digital volumetric informa- tion, is an important parameter in determining the spatial resolution and the resulting image detail [11]. Several stud- ies have investigated the eﬀects of changes in voxel size in terms of diagnosis. In these studies, external root resorption * Melek Tassoker dishekmelek@gmail.com 1 Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Necmettin Erbakan University, Ankara Street, 42050 Konya, Turkey