Accuracy of models of partially edentulous arches obtained by three-dimensional printing: An in vitro study

Aim: The aim of this study was to evaluate the accuracy of models of partially edentulous arches obtained by three-dimensional (3D) printing. Settings and Design: This was an in vitro study. Materials and Methods: Fifteen partially edentulous models were evaluated, using two methods of measuring dimensions: virtual, using the Standard Tessellation Language files of the models and software (control group), and physical, through printing the models and digital caliper (test group). For both methods, measurements were made regarding the dimensions of the teeth (width and length - buccal/lingual or palatal/occlusal) and distances between the teeth. Statistical Analysis Used: For the variable of linear measurements (width and length) and distances between teeth of the same hemiarch, the Wilcoxon test was used, while for the variable between opposite hemiarches, the paired t-test was used. Results: In the evaluation of the linear measurements, a significant difference was observed only when the width of the molar tooth was analyzed (P = 0.014). When the buccal length was measured, all teeth had linear measurements provided by the virtual method that was lower than the physical (P = 0.000), as well as the lingual/palatal length in incisors (P = 0.003) and molars (P = 0.009) and in total (P = 0.001). As for the analyses between teeth, no difference was identified between the measurements provided by the virtual method compared to the physical one. Conclusions: The 3D printer used to print partially edentulous models provided linear distortions in the teeth but without changes in the distances between teeth of the same hemiarch and between teeth of opposite hemiarches.