The post-traumatic colour change of primary incisors: a colourimetric and longitudinal study

Abstract

BackgroundTooth colour change after trauma has been described subjectively as ranging from yellow/pink to grey/black. AimTo investigate the longitudinal colourimetric change of post-traumatic discoloured primary incisor using an intraoral colourimeter. DesignA total of 34 primary incisors from 15 boys and eight girls were studied. The mean post-injury day during clinic visits (SD) and number of visit was 205.4 (194.8) and 3.9 (2.0). CIE L* (lightness), a* (green-red) and b* (blue-yellow) of the maxillary primary incisors were measured at every visit. The colour difference (E*(ab)) was calculated between the traumatized tooth and the control. Scatter graphs were made depicting the colour change of discoloured teeth and the E*(ab) over time. ResultsMean CIE L*, a* and b* of the unaffected control were 80.8 (2.29), 0.9 (0.77) and 13.1 (2.67), respectively. L* gradually decreased to 70.7 (on day 71), then slowly recovered. a* increased to 3.7 (day 29) and decreased slowly. b* only demonstrated a small change that was within the control range during the follow-up. E*(ab) increased to 9.58 (day 56) and decreased slowly. ConclusionThe earlier recovery of a* was followed by the recovery of L*. During the post-traumatic period, E*(ab) failed to reach the clinically acceptable threshold.