Comparison of the shade matching ability of dental students using two light sources

Abstract

Statement of problem: Shade selection is affected by a host of variables, including lighting.

Purpose: The purpose of this study was to assess the ability of dental students to match shades under natural lighting and using a light-correcting device, specifically to determine whether there are differences based on: (1) year in school, (2) gender of student, and (3) light source.

Material and methods: A 14-item shade matching quiz (SMQ) and a questionnaire were field tested. No major modifications were made to SMQ or questionnaire. Demographic information included year in school, age, gender, previous experience, and Ishihara's Tests for Color-Blindness. The SMQ was administered on separate occasions during the spring and summer, under natural light (SMQ-NL) and using the light-correcting device (SMQ-CL). For each of the 14 items, students (n=216) were to select the matching shade tab from 5 preselected tabs. Statistical analyses included ANOVAs, paired t tests, and independent t tests (alpha=.05).

Results: A total of 165 male and 51 female students participated, with an average age of 26 years. SMQ scores of 10 color-deficient students were excluded. There were no significant differences in SMQ-NL and SMQ-CL among the first through fourth year students (ANOVA), nor between men and women (t tests). The SMQ scores were significantly higher with the light-correcting device than with natural light: 11.4 +/- 1.9 and 10.4 +/- 2.0, respectively (paired t test, P<.001). With and without the light-correcting device, the Vita C shades were less likely to be matched than the Vita A or B shades (paired t tests, P<.001).

Conclusions: Dental students' shade matching abilities were better with a light-correcting source than under natural light. Gender and experience were not found to be factors in matching shades. The Vita C shades were least likely to be matched.