Accuracy and reproducibility of 3-dimensional digital model measurements

IntroductionThe purpose of this study was to evaluate the reliability of measurements made on 3-dimensional digital models obtained with a surface laser scanner (D-250; 3Shape, Copenhagen, Denmark).MethodsTwenty orthodontic dental casts of permanent dentitions were selected. Three-dimensional images were obtained on this scanner and analyzed by using the Geomagic Studio 5 software (Raindrop Geomagic, Inc, Morrisville, NC). Measurements were made with a digital caliper directly on the dental casts and also digitally on the digital models. Fifteen anatomic dental points were identified, and a total of 11 linear measurements were taken from each cast, including arch length and width. Dependent t tests were used to evaluate intraexaminer reproducibility and measurement accuracy on the digital models.ResultsNo statistically significant differences were found between the measurements made directly on the dental casts and on the digital models.ConclusionsLinear measurements on digital models are accurate and reproducible. Digital models obtained with the surface laser scanner are reliable for measurements of arch width and length.