Reliability and accuracy of Crystaleye spectrophotometric system.
OBJECTIVE
to develop an in vitro shade-measuring model to evaluate the reliability and accuracy of the Crystaleye spectrophotometric system, a newly developed spectrophotometer.


METHODS
four shade guides, VITA Classical, VITA 3D-Master, Chromascop and Vintage Halo NCC, were measured with the Crystaleye spectrophotometer in a standardised model, ten times for 107 shade tabs. The shade-matching results and the CIE L*a*b* values of the cervical, body and incisal regions for each measurement were automatically analysed using the supporting software. Reliability and accuracy were calculated for each shade tab both in percentage and in colour difference (ΔE). Difference was analysed by one-way ANOVA in the cervical, body and incisal regions.


RESULTS
range of reliability was 88.81% to 98.97% and 0.13 to 0.24 ΔE units, and that of accuracy was 44.05% to 91.25% and 1.03 to 1.89 ΔE units. Significant differences in reliability and accuracy were found between the body region and the cervical and incisal regions. Comparisons made among regions and shade guides revealed that evaluation in ΔE was prone to disclose the differences.


CONCLUSIONS
measurements with the Crystaleye spectrophotometer had similar, high reliability in different shade guides and regions, indicating predictable repeated measurements. Accuracy in the body region was high and less variable compared with the cervical and incisal regions.
Department of Oral and Maxillofacial Radiology, Peking University School and Hospital of Stomatology, Beijing, P.R China.
Li
L
Chen
Jian Guo
JG
Tan
Jian Feng
JF
Zhou
Xu
X
Yang
Yang
Y
Du
Fang Ping
FP
Wang
D003116:Color / Q000592:standards*; D003442:Crowns; D005881:Gingiva / Q000033:anatomy & histology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D003765:Models, Dental; D013053:Spectrophotometry / Q000295:instrumentation* / Q000379:methods; D019237:Tooth Cervix / Q000033:anatomy & histology; D019228:Tooth Crown / Q000033:anatomy & histology*