Accuracy of lab scanners in establishing dental measurements: In-vitro study

Abstract

To determine the accuracy of the measurements made by the lab scanner on rubber-based impressions, the scanned plaster models, and the conventional plaster models by digital vernier calliper. The sample comprised of 20 randomly selected patients. Two sets of maxillary rubber base impressions were taken. The samples were then divided into three groups In Group A, stone casts obtained from the first rubber base impression, were measured manually using a digital vernier calliper having an accuracy of 0.01 mm. In Group B, the second rubber base impressions were measured using a lab scanner (3 shapes series E3) and finally in Group C, the stone models used in group A were scanned by the lab scanner and measurements were performed on 3 Shapes Ortho analyser software. The total of 9 linear measurements made were mesial distal tooth width, arch perimeter, arch length, buccolingual width, clinical crown height, intercanine, inter first premolar, inter second premolar and intermolar distance. The measurements were done twice and average value was recorded as the final result. Data were tabulated and analysed statistically. One way ANOVA test was done to analyse the differences between measurements. Results showed no statistically significant difference between mesial distal tooth width, arch perimeter, arch length, buccolingual width, clinical crown height, intercanine, inter first premolar, inter second premolar and intermolar distance. Digital models were as accurate as the manual measurements performed on casts by digital vernier calliper in establishing linear measurements. Thus, digital models were proven to be reliable and clinically acceptable.