The Trios Scanner Color Determination Function: An In Vitro Comparison Study

Abstract

Effectively matching a new restoration to the existing dentition is an important objective than can help create a harmonious smile. The 3Shape Trios Color Scanner offers to identify shades of scanned teeth to help improve the esthetic outcome of restorations. The purpose of this in vitro study was to assess the ability of the Trios to identify Vita 3D Master Linearguide shade tabs for overall shade, and across value, hue, and chroma. Tab shades were validated using the Vita Easyshade Compact spectrophotometer. The middle thirds of the tabs were scanned, and the Trios output was recorded. The proportion of scans correctly matched for total shade, and the separate proportions for correctly matched values, hues, and chromas were found. Spearman correlations were computed for tab value versus scan value and tab chroma versus scan chroma. For hue, a chi squared test was used to compare population proportions and machine proportions.

The Trios correctly matched overall shade 75.00% of the time, value 99.29% of the time, and both hue and chroma 77.86% of the time. For the hue chi squared test, the distribution of Trios-reported hues was different from the true population distribution. The machine-reported value and chroma were highly correlated with the tab value and chroma, with correlation coefficients ρ of 0.998 and 0.936, respectively, that were significant at the 0.01 level. There was no trend for value, but scan chroma was the most accurate when tab chroma was between 1.5 and 2.0. Past this range, the Trios had a slight trend of overestimating chroma, and below this range, the Trios had a trend of underestimating chroma. These data suggest that the Trios may be a helpful adjunct for dental shade matching, especially for value determination. However, the final assessment should be made by the dentist and confirmed by the patient.