Comparison of Shade Reproduction Accuracy With Digital SLR Cameras and Digital Spectrophotometer – A Controlled Clinical Trial

Objectives: To compare the shade matching accuracy using digital images from the entry level Nikon D5200, Canon 600D & the Sony Alpha58 to that of spectrophotometry.
Methods: In this study, upper right central incisor shade of 40 patients were evaluated with spectrophotometric reading as control with digital photographs with three SLR cameras as individual test groups. The digital images obtained using imaging software (Adobe Photoshop CS6) were converted into CIEL*a*b* values using a conversion software (Colormine) and the RGB (Red,Blue,Green) values of the upper right central incisor of the digital images were compared.
Results: Comparison of CIEL*a*b* values between each group revealed a significant difference with images from the Nikon camera displaying more accurate colours (72.5%; p<0.05) compared to images from the Canon (35%; p<0.05) and Sony (40%; p<0.05) cameras. SPSS v18. Statistical software (IBM) was used to evaluate the data with the three test groups (Nikon, Canon & Sony) to the Control group (Spectro). Chi-Square test was used between the groups and statistical analysis revealed that the test group with digital photographs taken with the Nikon camera performed significantly better (72.5%; p=0.00) compared to the other two groups (Canon – 35%; p= 0.00 & Sony – 40%; p= 0.00) respectively.
Conclusions: Shades evaluated from images taken with the Nikon camera had a higher percentage of positive matching followed by Canon & Sony compared to shades from control group. Based on the results of the current study the use of the entry level Nikon D5200 camera can be recommended for use in the dental practice for accurate shade matching.