[A study of color measurement for vital teeth using digital camera].
OBJECTIVE
To evaluate the reliability and reasonability of tooth color matching by using the digital camera.


METHODS
322 maxillary incisors from 161 Asia volunteers aged between 20 to 40 years were recorded by a Canon EOS D60 digital camera in studio environment (D65 standard illuminant). Photographs were taken under a set exposure parameters( AE f/2.8, 1/45s, ISO 100) and saved in RAW image file format. The characteristics of color of the tested teeth were visually observed, and the color values were obtained from the digital images using Camera RAW for Adobe Photoshop 8.0 and quantified according to an internationally recognized scale as CIELAB color values, L*a*b*/C*H degrees . All data were analyzed in descriptive statistics and compared in Wilcoxon analysis using SAS8.1 software package.


RESULTS
There were 49.8% of samples shown an uneven distribution of color, 14.1% had abnormal pigment. The color parameters of all tested vital teeth were: L*39.928-75.681, a*-1.543-5.8284, b*5.5764-22.591, the tolerance of deltaEab<2.8NBS.


CONCLUSIONS
The assessment of vital tooth color depend on sort of measurement and instrument, however, the method of tooth shade matching by digital camera seems reliable and advantageous.
Ge
Qi-min
QM
Department of Prosthodontics, Ninth People's Hospital, College of Stomatology, School of Medicine, Shanghai Jiao Tong University, Shanghai Research Institute of Stomatology, Shanghai 200011, China.
Zhang
Fu-qiang
FQ
D000328:Adult; D003116:Color; D006801:Humans; D023861:Photography, Dental; D017797:Prosthesis Coloring; D014070:Tooth; D055815:Young Adult