Validity of wax and acrylic as soft-tissue simulation materials used in in vitro radiographic studies

Objective: To determine the thickness of wax and acrylic that provides a radiographic density similar to that of the human cheek. Methods: An intraoral film radiograph of the human cheek including a 40 x 30 x 3 mm reference aluminium block was recorded under standardized conditions in 61 subjects. Radiographic density was measured by a densitometer in ten randomly selected sites of the film to serve as the gold standard for density values of the cheek soft tissues. Thereafter, the density of series of radiographs of two tissue-simulating materials-wax and acrylic-in systematically increasing thicknesses (wax, 1.5-30 mm; acrylic, 2-40 mm) plus the reference block were measured and compared with the gold-standard values. Results: The radiographic density of wax with a thickness of 13-17 mm or acrylic with a thickness of 14.5 mm corresponded to the average density of the human cheek. Conclusion: The soft tissues of the average human cheek can be simulated with 13-17 mm wax or 14.5 mm acrylic in in vitro radiographic studies. Dentomaxillofacial Radiology (2012) 41, 686-690. doi: 10.1259/dmfr/33467269