Comparison of Play Dough and Bread Dough with Ballistic Gel as Soft Tissue Simulator: An Ex-Vivo Study with Sheep’s Head as the Gold Standard

Objective: This study aims to test the usability of bread dough, play dough, and ballistic gel in soft tissue simulations by comparing them with a sheep’s head as the gold standard. Cone beam computed tomography (CBCT) images of the sheep’s head was obtained as the gold standard. Methods: The sheep’s head was re-covered with ballistic gel, play dough, and bread dough, respectively. Two different CBCT images (protocol A- FOV: 8x15cm, 90kVp, 6.3mA, 4.5s, 0.35mm-voxel size, 574 mGy cm2; protocol B- FOV: 13x15cm, 90kVp, 5mA, 8.1s, 0.30mm-voxel size, 823 mGy cm2) were obtained from the gold standard and each simulation model. The Hounsfield unit (HU) feature in the software of the CBCT was used to evaluate gray values. Pearson Correlation Coefficient was used to examine the relationship between variables that comply with normal distribution, and Spearman’s rho Correlation Coefficient was used to examine the relationship between variables that do not comply with normal distribution. The significance level was taken as p < 0.05. Results The highest positively significant correlation with the gold standard in the mandible was with bread dough (r = 0.944, p < 0.001), while in the maxilla it was with play dough (r = 0.879, p < 0.001). The highest positive significant correlation with the gold standard in gray values selected from teeth and bone was with ballistic gel (r = 0.762, p=0.004; r = 0.638, p=0.008, respectively), while in pulp it was with play dough (r = 0.874, p < 0.001). A very high, positive, and significant correlation was found between protocols A and B of all simulation models. The highest positive significant correlation of the gold standard protocol A was found with the ballistic gel simulation protocol B (r = 0.893, p < 0.001). Conclusion: Play-dough can be an alternative soft tissue simulator to ballistic gel, especially in ex vivo studies on pulp morphology.