RESUMEN
BACKGROUND: Accurate laser scanning of plaster casts using validated, low-cost hardware represents a key issue in 3D orthodontics. OBJECTIVES: The aim of this study was to compare the accuracy of measurements taken from plaster casts (gold standard) with digital models of those casts created with a low-cost structural light DAVID laser scanner. MATERIAL AND METHODS: Five different measurements were taken on each of 14 plaster casts by 2 independent observers with an electronic caliper. The measurements were repeated 10 times on all 14 plaster casts by each observer, with a 1-week interval between each set of measurements. All 14 plaster casts were digitized using a low-cost DAVID SLS 3 laser scanner. The same 5 measurements were performed on each of the 3D virtual surface models of the 14 plaster casts by 2 independent observers using Meshlab software in a manner similar to that used with the digital caliper. The measurements were repeated 10 times by the 2 observers with 1 week between each set of measurements. RESULTS: The laser-scanned models were more accurate than the plaster cast models in defining measurements based on simple tooth fissures. The accuracy of measurements based on complex tooth fissures were equivalent for the 2 types of model. For measurements based on interproximal dental contacts, the 2 methods of measurement were similar and both were notably poor in terms of accuracy. CONCLUSIONS: Three-dimensional virtual models obtained from the low-cost DAVID laser scanner can be used clinically, but only for certain types of measurements and indications.