EVALUATION OF MULTIPLE SYNTHETIC MATERIALS IN REPLICATION OF SOFT TISSUE DENSITY TO AID STANDARDIZATION IN CBCT BASED EX VIVO STUDIES

Abstract

<h3>Background</h3> With a significant increase in the use of imaging in dentistry, several proof of concept studies are being done before embarking on larger-scale studies. Most studies that use ionizing radiation have to be very carefully vetted before conducting a larger sample study and would require simulation of a live human tissue and clinical environment to the best possible extent. There is a significant increase in the number of studies being done with cone beam computed tomography (CBCT), and researchers have struggled with standardization of materials that best simulate the same density of tissues in a patient. Although hard tissue, with the use of dry skulls, is less challenging to simulate, soft tissue often poses a major challenge. <h3>Objective(s)</h3> The aim of this study was to evaluate the adequacy of multiple materials to best simulate soft tissue density, as measured by pixel intensity values on CBCT scans. <h3>Study Design</h3> Four different materials—boxing wax, utility wax strips, cotton rolls, and methyl methacrylate (MMA) polymer—were imaged using the Morita Accuitomo CBCT scanner at 88 kVp and 10 mA. The pixel values were compared with the values of soft tissue, check, lip, and tongue. Using axial, sagittal, and coronal views, 50 different points were measured for each material. Image evaluations were done using a CBCT reconstruction program, InVivoDental Version:5.3 (Anatomage Inc., San Jose, CA) to determine the pixel values. <h3>Results</h3> All 4 materials showed comparable pixel values. The mean values were 186, –16, – 25, and –565 for MMA polymer, boxing wax, utility wax, and cotton rolls, respectively. For the control group, the mean values were –28, 58, 73, and 26 for lips, tongue, check soft tissue, and water, respectively. <h3>Discussion/Conclusions</h3> All the evaluated material had comparative pixel values. Future studies evaluating other materials and different CBCT machines could help in standardization for soft tissue simulation.