The in vitro and in vivo validation of a mobile non-contact camera-based digital imaging system for tooth colour measurement.
OBJECTIVE
To assess the reproducibility of a mobile non-contact camera-based digital imaging system (DIS) for measuring tooth colour under in vitro and in vivo conditions.


METHODS
One in vitro and two in vivo studies were performed using a mobile non-contact camera-based digital imaging system. In vitro study: two operators used the DIS to image 10 dry tooth specimens in a randomised order on three occasions. In vivo study 1:25 subjects with two natural, normally aligned, upper central incisors had their teeth imaged using the DIS on four consecutive days by one operator to measure day-to-day variability. On one of the four test days, duplicate images were collected by three different operators to measure inter- and intra-operator variability. In vivo study 2:11 subjects with two natural, normally aligned, upper central incisors had their teeth imaged using the DIS twice daily over three days within the same week to assess day-to-day variability. Three operators collected images from subjects in a randomised order to measure inter- and intra-operator variability.


RESULTS
Subject-to-subject variability was the largest source of variation within the data. Pairwise correlations and concordance coefficients were > 0.7 for each operator, demonstrating good precision and excellent operator agreement in each of the studies. Intraclass correlation coefficients (ICCs) for each operator indicate that day-to-day reliability was good to excellent, where all ICC's where > 0.75 for each operator.


CONCLUSIONS
The mobile non-contact camera-based digital imaging system was shown to be a reproducible means of measuring tooth colour in both in vitro and in vivo experiments.
Smith
Richard N
RN
International Collaborating Centre in Oro-facial Genetics and Development, Liverpool University Dental Hospital & School of Dentistry, Edwards Building, Daulby Street, Liverpool L69 3GN, UK.
Collins
Luisa Z
LZ
Naeeni
Mojgan
M
Joiner
Andrew
A
Philpotts
Carole J
CJ
Hopkinson
Ian
I
Jones
Clare
C
Lath
Darren L
DL
Coxon
Thomas
T
Hibbard
James
J
Brook
Alan H
AH
D000293:Adolescent; D000328:Adult; D000368:Aged; D003116:Color; D003124:Colorimetry / Q000295:instrumentation; D003481:Cuspid / Q000033:anatomy & histology; D004867:Equipment Design; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D007180:Incisor / Q000033:anatomy & histology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D023861:Photography, Dental / Q000295:instrumentation*; D015203:Reproducibility of Results; D013997:Time Factors; D014070:Tooth / Q000033:anatomy & histology*