Prototype of a 2.5D Periapical Radiography System Using an Intraoral Computed Tomosynthesis Approach

[[abstract]]Digital periapical radiography is widely used in clinical dentistry because the technique is relatively simple and inexpensive. However, the main drawback of periapical radiography is that it represents a three-dimensional object in a two-dimensional film due to its inherent projection technique. The objective of this study was to develop a prototype intraoral computed tomosynthesis system, which can provide quasi-three-dimensional (so-called 2.5D) images. We developed a prototype intraoral computed tomosynthesis machine. Regular digital periapical radiography, computed tomosynthesis scanning, and computed tomography scanning of a human central incisor were performed. Then, reconstruction images obtained using computed tomosynthesis and computed tomography approaches were quantitatively evaluated using the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). From the experimental results, compared with periapical radiographic images, reconstruction images obtained using the computed tomosynthesis approach revealed detailed microstructures in different depth sections. In addition, the SNR and CNR of reconstruction images obtained using the computed tomography approach was better than those of the images obtained using the computed tomosynthesis approach. However, the differences could not be clearly identified by the naked eye. The preliminary experimental results indicate that an intraoral computed tomosynthesis system may be useful for clinical dental diagnosis