Color Accuracy of Smartphone Camera Attachment for Dental Shade Selection

Objectives: To compare the color accuracy of a smartphone camera with specialized attachement, to the accuracy of a commercial DSLR camera and a portable contact-type spectrophotometer in a simulated clinical setting uisng multivairate transofrmation analysis.
Methods: Extracted human teeth (n=6) were mounted into a dental simulation unit. 3 images of each tooth were captured using the Apple iphone 5 with SmileLite attachment, Nikon 3100 DSLR, and Vita EasyShade Advance V4. Color differences (dE) were calculated for the CIELab data points before using Generalized Procrustes Analysis (GPA).
Results: EasyShade vs. SmileLine= Ave PreCalibration Error = 22.0138 4.86646 13.3794
Prediction Error Mean = -0.023746 0.0069538 0.0043609. Prediction Error StdDev = 6.5881 1.4521 3.3611
EasyShade vs. Nikon=Ave PreCalibration Error = 30.8975 -8.33465 1.69184
Prediction Error Mean = -0.055209 0.21998 0.29243
Prediction Error StdDev = 6.112 1.0686 3.4022
Conclusions:
Procrustes analysis can be simultaneously used as a calibration method, and a statistical analysis of errors, and ultimately provide intuitive qualitative and quantitative information for subsequent work.
The smartphone camera has very high precision, but it is inaccurate in recording color without applying (GPA) transformation.