Shade-matching abilities of dental laboratory technicians using a commercial light source

The purpose of this study was to evaluate dental laboratory technicians' abilities to match shades using a light-corrective device under conventional laboratory conditions. The variables measured were years experience, gender, and light source.

A 14-item shade-matching quiz (SMQ) was field-tested and deemed adequate. Information included age, gender, number of years experience, and Ishihara's Colour-Blindness Assessment. Forty-two dental technicians from five northeast Ohio laboratories were invited to participate. The SMQ was administered twice: under the lighting conditions in the individual laboratories (SMQ-Lab) and with a light-corrective source (SMQ-LC). For each item, the technicians were to select the matching Vita shade tab from five preselected shade tabs. SMQ scores equaled the number of correct matches. Statistical analysis included calculation of means, standard deviations, correlation coefficients, and independent and paired t-tests. Significance was set at p

Twenty male and 20 female technicians participated. None were color-deficient. The SMQ scores were significantly higher with the light-corrective device than under laboratory lighting: 12.0 +/- 1.9 and 10.0 +/- 2.0, respectively (p < 0.001). There were no significant correlations between years experience and SMQ scores, nor were there differences between scores by gender. In general, the Vita C shades were least likely to be matched.

Within the limitations of this study, dental technicians' shade-matching abilities were better with a light-corrective device than under the conventional laboratory lighting conditions. Gender and experience were not factors in matching shades. The Vita C shades were least likely to be matched.