Objectives: To investigate the relationship between tooth yellowing in relation to age in a UK practicebased population.
Methods: As part of a larger study that considered changes in overall tooth color with age. The upper
right central incisor of 658 subjects, in age cohorts of 7-10, 11-17, 18-25, 26-35, 36-45, 46-55, 56-65
and >65 years was measured with the Vita EasyShade tooth color measurement device. From this
device CieLab values were reported and subsequently perceptual yellowness values were calculated
using a new yellowness equation optimised for tooth color (YIO). The relationship between age and
tooth yellowness was tested using a linear regression model. Data are reported for b* (blue-yellow
vector of CieLab) and YIO.
Results: As previously reported the youngest subjects’ teeth became lighter (0.5 BG shades) for all
metrics including YIO up to the age of around 18 years and then became increasingly darker. For this
reason, the slope of the relationship between age and yellowness was evaluated in those subjects 18
years and above (n=526). For b* and YIO, the slopes of the regression were 0.133 and 0.914
respectively representing 7.5 and 1.1 years per unit change for each metric.
Conclusions: Teeth become linearly perceptually yellower with age above the age of 18 years. A
single unit change in YIO representing 1.1 years.