Color distribution of maxillary primary incisors in Korean children

Abstract

The purpose of this study was to investigate the color distribution of maxillary primary incisors measured with a colorimeter. The subjects were 100 Korean children aged 2-5 with total number of 400 teeth. A spot measurement intraoral colorimeter was used to determine the color of maxillary primary central and lateral incisors at labial central area. The CIE L*, a*, b* value of each tooth and color difference (ΔE*ft) among each other were calculated and analyzed. The range of L*, a*, and b* values, regardless of the type of teeth, was 72.7-84.9, 20.6 to 4.9, and 4.7-15.0, respectively. Mean value (SD) ofL*, a*, and b* for maxillary primary incisors was 78.6 (2.3), 1.2 (0.9), and 9.6 (1.8), respectively. Boys showed more red (higher a* value) and less yellow (lower b* value) hue than girls in the central incisors (P < 0.05). Mean color difference (ΔE*ft) (SD) between two values which selected from overall 400 L*, a*, b* values measured (n = 400C 2 ) was 3.9 (1.8) with 95% confidence interval range of 3.86-3.89, and most of them were found to be present around the previously reported clinical acceptability thresholds (ΔE*ab = 2.7-6.8). Because mean intraperson ΔE*ab (SD) was 3.0 (1.6) with 95% confidence interval range of 2.86-3.12, most colors among primary incisors in the same person were presumably difficult to discern by naked eye (ΔE*ab < 3.7). Age influenced L* and b* values significantly, but the correlation coefficients were not high (r = 20.182 for L* of central incisors, P < 0.01; r = 0.188 for b* of central incisors, P < 0.01; and r = 0.143 for b* of lat-eral incisors, P < 0.05). The present study showed somewhat higher color coordinates than the previous reports which based on primary anterior teeth in other ethnic groups. The results of this study could be used for the color modification of esthetic materials for primary teeth.