Vol. 1 – Number 2 – 2021
Original article
Page 40-53
Three-dimensional digital models accuracy and reliability: Exceed™ software validation
Fernando César Moreira¹
Luis Geraldo Vaz¹
Jeryl D English²
Helder Baldi Jacob²
ABSTRACT
Introduction: CAD/CAM systems help orthodontists in the production of aesthetic aligners and in indirect bonding (virtual bracket positioning) in three-dimensional digital models. This study evaluated the accuracy and validity of eXceedTM software. Methods: Twenty patient plaster models were digitized by a desktop scanner, and the files obtained were converted to stereolithography by OrthoAnalyser™ software. Using the cast and digital models, six measurements were performed: Intermolar Width (LM); Intercanine Width (LC); Posterior Arch Length (CA); Premolar Crown Diameter (DP); Canine Crown Height (AC) and Overjet (OJ). Intraobserver systematic errors between replicates were described as mean absolute differences and standard errors (SE); statistical analyzes were evaluated using a paired Students t test. Random errors were quantified using the method error statistic [√Σ(d2/2N)] and Intraclass Correlation Coefficient (ICC). Differences between methods was evaluated using Students t test. Results: Two of the measurements of the replicas in the digital model (CA) and in the plaster model (LC) showed statistically significant systematic errors. The ICC ranged from 0.916 to 0.997. The method errors were all less than 0.41 mm (0.22 mm). Bland-Altman plots showed that the differences of repeatability between the two methods were within the limits of agreement. The values DP (0.253 mm), LC (0.396 mm), AC (0.314 mm) and CA (0.359 mm) were higher in plaster models than in digital models. Conclusion: The measurements performed in both methods were reliable and reproducible, and plaster models measurements were slightly higher than those of the corresponding digital models.
Descriptors: Orthodontics, computer-aided design, dental models, dimensional measurement accuracy, dental technology.
¹ UNESP – Dentistry University, Araraquara, Department of Dental Materials and Prosthesis.
² The University of Texas Health Science Center at Houston School of Dentistry, Department of Orthodontics – Houston/Texas – United States.
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