Clinical Color Selection Reliability of Conventional Versus Digital Methods

Objectives: The aim of this clinical study was to evaluate intra- and inter-observer reliability of 3 postgraduate students in natural tooth color selection using different conventional or digital tools.
Methods: Color measurements were captured by three postgraduate students from the Department of Restorative Dentistry. Before starting the study, students were calibrated by giving lectures on tooth color selection. In 32 healthy patients, tooth colors were determined using 4 different conventional or digital tools on the maxillary right or left central incisor teeth. The conventional tools for visual color selection were VITA Classical (VC) and VITA 3D (V3D) shade guides (VITA Zahnfabrik). Digital color measurements were performed with a spectrophotometer (VE:VITA Easyshade V, VITA Zahnfabrik) and a digital camera (Canon D80 with a 100 mm macrolens and a twin flash). From an anterior composite resin set, enamel (incisally) and dentin (cervically) colors were temporarily adhered to the facial surface of the tooth using the button technique and then digital photos were taken with the camera. Color selections were conducted on computer over photographs. The enamel (E1) and dentin (D1) colors were first made on the original photographs. The enamel colors (E2) were made secondarily by converting the photographs to black and white. Dentin colors (D2) were also selected secondarily by increasing the contrast of the photos. The data were recorded and statistically analyzed with intraclass correlation coefficient (ICC).
Results: In terms of intra-observer reliability, there was poor reliability between the VC-V3D (O1=0.31,O2=0.22,O3=0.47), VC-VE (O1=0.3,O2=0.1,O3=0.03) and V3D-VE (O1=0.002,O2=0.03,O3=0.08) color selection methods, while the reliabilities between E1-E2 (O1=0.57,O2=0.78,O3=0.54,p<0.05) and D1-D2 (O1=0.8,O2=0.61,O3=0.69,p<0.05) were good for all three observers. Reliability results between the observers were good for evaluations over photographs only (E1=0.5,E2=0.5,D1=0.5,D2=0.6,p<0.05), while reliabilities were poor for the other methods.
Conclusions: Color selection can be made safely in the aesthetic region by using the button technique over digital photographs.