Colorimetric and visual assessment of two-color chewing gum mixing ability test: Correlation and reference parameters in dentate subjects.

Objective This study assessed the chewing performance of dentate subjects, using mixing ability tests with two-colored chewing gums, and aimed to correlate the visual and optoelectronic measurement methods to provide a correspondence scale for predicting the standard deviation of hue (SD-Hue) values based on visual parameters and the number of chewing strokes.Design Two chewing gums were used (Hue-Check Gum® and Vivident Fruitswing®), and tests were performed with 1, 5, 10, 15, 20, 25, and 30 chewing cycles. The analysis included optoelectronic analysis to measure the level of color mixture (ViewGum software) expressed as the SD-Hue, ranging from 0 to 1, where lower values correspond to a higher level of mixture, and subjective analysis (SA) on a 5-point ordinal scale. Data analysis included bivariate correlation, definition of double-sided 90 % reference ranges, and GEE regression.Results There were significant correlations between SD-Hue and the number of chewing cycles and SA scores (p < 0.001), and SA score was strongly correlated with the number of chewing cycles (p < 0.001). A downward logarithmic curve for SD-Hue and SA can be observed according to the number of chewing cycles. The mixture level progressively increased by approximately 50 % for each five chewing cycles.Conclusion It was possible to correlate visual and optoelectronic methods and to establish a scale prediction of SD-Hue values based on SA and the number of chewing cycles. The color mixing measured by optoelectronic and visual methods was proportional to the number of chewing cycles. For every five cycles, the level of color mixture was reduced by 50 %, expressed in a downward logarithmic curve, independently from the chewing gum type.