Abstract

FREITAS, Guilherme D'Agostino Romanini de et al. Fabrication of plaster models with radiographic features of human bone: a pilot study by fractal analysis. RGO, Rev. gaúch. odontol. (Online) [online]. 2012, vol.60, n.2, pp. 163-167. ISSN 1981-8637.

Objective This study attempted to fabricate plaster models that reproduce the radiographic characteristics of human bone. Methods A section of an edentulous dry mandible was radiographed and molded. The inside of the templates was lined with dental wax and filled with gypsum plaster mixed with sawdust or rice flour in proportions of 25%, 33.3% and 50% to simulate the trabecular pattern. Once this mixture settled, the wax lining was removed and the space filled with stone plaster to simulate the cortical bone. Three plaster models were fabricated for each proportion of each material. The models were radiographed and the radiographs that best resembled that of human bone were selected, one for each proportion of each material. The chosen radiographs were digitalized, and the digital images were Gaussian-blurred, binarized, skeletonized and submitted to fractal analysis. Results All binary (p=0.000) and most skeletonized (p=0.000) images of the two groups were significantly different from that of the human mandible section, except for the skeletonized image of the model containing 50% rice. Conclusion Although the results of this study did not allow consistent conclusions, they showed that the methodology is appropriate and practical for other similar studies. More studies are needed using different proportions of the same materials and bigger sample sizes for more reliable assessments of different mixtures.

Keywords : Bone density.; Calcium sulfate.; Dental radiography..