Accuracy of an intraoral digital scanner in tooth color determination

Abstract

Statement of problem: Whether intraoral digital scanners with an integrated shade-taking function can substitute for colorimeters, spectrophotometers, or the visual method to reduce working time is unclear.

Purpose: The purpose of this clinical study was to evaluate the accuracy of the measurement of tooth shade obtained with an intraoral digital scanner in vivo.

Material and methods: Shades of 120 maxillary anterior teeth were evaluated by using a SpectroShade spectrophotometer (SS) and a TRIOS 3 intraoral digital scanner (T3) on 20 participants. The matching of shade readings between the T3 and SS was used to estimate the accuracy of the T3. The percentage of readings when a difference between the shades obtained by both devices was visually perceptible (ΔE>3.7) was calculated. Each of the 120 teeth was measured 5 times to assess repeatability.

Results: The accuracy of the T3 was 53.3% when the color was recorded as a Vita 3D-Master (VM) shade and 27.5% for the Vita Classical (VC) shade guide when the SS was taken as a reference. A visually perceptible color difference was found in 25% (VM) and 50.8% (VC) of situations when the shade was determined with the SS and 48.3% (VM) and 78.3% (VC) with the T3. Repeatability was 92% (VM) and 93.5% (VC) for the SS, and 90.33% (VM) and 87.17% (VC) for the T3.

Conclusions: The findings of this study revealed that the tooth color determined by the T3 does not exactly match that obtained by the SS that additional methods of measuring tooth color are recommended. The accuracy of the T3 was higher when the color was recorded as VM values rather than VC values.