Comparison of Visual and Spectrophotometric Methods for Dental Color Measurement - An in Vivo Study

Overview

Twenty patients of Dental Medicine School will be recruited to participate in a pilot study about dental color measurement in which visual and digital instruments will be tested. Informed consents and local ethical committee clearance will be previously obtained. All data will be collected after an oral hygiene procedure. Two different methods of color measurement will be tested: visual method with VITA Classical (VC) and VITA 3D-Master (VM) and digital method with Spectroshade Micro (SS) and VITA Easyshade (ES). The CIE L\*a\*b\* values will be evaluated in the VC scale for both methods. Reproducibility will be assessed based on intra-operator intra-device agreement and the accuracy will be assessed based on inter-device agreement using the kappa coefficient (K) and intraclass correlation coefficient (ICC), respectively. Results will be presented as mean, with 95% CI

Clinical practice in Dentistry has been changed during the times, with a large development of aesthetics considerations. Tooth color is an effect of volume reflection, the passage of incident light through the tooth followed by backward emergence. Color can be categorized in different systems and CIE L\*a\*b\* is the most common. For color acquision visual and digital methods are used. Tooth shade matching in daily clinical practice is still a cause of disagreement and discomfort for many professionals. The gold standard is the use of dental shade guides by the clinicans who make a comparison between the sample (tooth) and multiple standard guides (shade guide tabs). The gold standard visual system has been Vitapan Classical (VC). Other system is Toothguide 3D-Master (VM) which applies more closely the accepted color perception concepts of hue, lightness, chroma. However, several limitations have been associated to visual procedure. The accuracy between clinicians is frequently low and there is a high variability. For this reason, many improvements in optical electronic devices have led to the expanded use of photometric and colorimetric techniques for the evaluation, specification and management of color. Although the effectiveness of these devices depends ultimately on the accuracy and precision with which the measurements are carried out. There is a deeply concern with the determination of the accuracy between different methods for colour acquision because color has to be communicated precisely.