Assessment of full frame and crop frame DSLR cameras for dental shade selection: in vitro comparative study

Introduction
Shade selection is a critical step in the creation of esthetic restoration. There are several methods to determine dental shades. Digital photography has evolved as practical method for determining tooth colors. Dental photography still makes extensive use of DSLR cameras, which are divided into two types: full frame and crop frame based on sensor size.

Objectives
This study employed spectroradiometer as a standard to evaluate the hypothesis that there is no diffe­rence in the accuracy of shade estimation using full frame and crop frame DSLR cameras.

Material and methods
Twenty-six Vita 3D-Master shade guide tabs were imaged using two full frame (Nikon D610 and Canon 5D MIII) and four APS-C (Canon 80D, Canon 750D, Nikon D7200, and Nikon D5600) cameras with Tamron 90 mm lens. Photoshop was used to calculate CIE-Lab values. Color difference (∆Eab) between digital images and control values obtained with a spectroradiometer (SpectraScan PR-670) of the same shade tabs were analyzed using one-way ANOVA and Tukey’s HDS post-hoc test.

Results
There were statically significant differences (p > 0.05) in ∆Eab values between spectroradiometer and DSLR cameras, and between FX and APS-C DSLR cameras.

Conclusions
Within the limitations of this study, full frame DSLR cameras are able to provide more accurate information on shade selection than crop frame DSLR cameras. Using a full frame camera is highly recommended when communicating with a dental lab regarding dental shade.