Evaluation of different soft tissue-simulating materials in pixel intensity values in cone beam computed tomography.

OBJECTIVE: This study aimed to evaluate different materials as soft tissue simulators and the influence of soft tissues in cone beam computed tomography. STUDY DESIGN: Images of 5 piglet heads were acquired with intact soft tissues, with the tissues stripped, and with the use of different soft tissue simulators, following the same acquisition protocol. Four different materials were tested, individually or in combination: acrylic, water, utility wax, and expanded polystyrene (EPS). Pixel intensity values of 8 quadrangular regions, that is, upper and lower teeth and alveolar bone, were obtained. The mean values were used for comparison by analysis of variance (ANOVA; α = 5%). RESULTS: No differences were observed for the "No Material," "EPS," "Acrylic," and "EPS and Wax" groups for the lower anterior and posterior teeth, the upper posterior tooth, and the anterior and posterior bone, and for the "No Material," "EPS," and "EPS and Wax," groups for the lower posterior bone. All groups showed statistical differences for the lower anterior bone and the upper anterior tooth. CONCLUSIONS: Expanded 2-cm thick polystyrene, with or without 1-cm thick utility wax, was effective for most regions, followed by acrylic 0.5 cm. Soft tissues were not of great influence in most regions. Water was not an effective material for any of the regions.