In vivo study for tooth colour determination-visual versus digital

Abstract

Objectives: Tooth colour determination is an essential component in the preservative and prosthetic workflow during production of tooth-coloured restorations. The aim of the study was to compare the clinical suitability of conventional, visual tooth colour determination and digital methods.

Materials and methods: Tooth colour of vital, natural central incisors among a total of 107 subjects was determined visually by a dentist (VD) and dental technician (VDT) using VITA Toothguide 3D-MASTER®, digitally by the spectrophotometer VITA Easyshade Advance 4.0 (reference instrument) and Trios®Color intra-oral scanner (test subject). Reliability was examined by repeating the digital measurements of 20 teeth three times. The analysis was based on the recorded 3D-MASTER values and L*a*b/L*C*h parameters.

Results: The measuring accuracy was 43.9% with the Trios®Color scanner, 35.5% for VD and 34.6% for VDT. In 25.5% of cases, the scanner's results corresponded with VD and in 33.6% with VDT. The visual methods corresponded with 45.8%. All mean values of the recorded colour differences fell within the clinically acceptable range of ΔE ≤ 6.8. The intra-oral scanner attained repeatability of 78.3% and the VITA Easyshade system of 76.6%.

Conclusions: The Trios®Color intra-oral scanner appears to be a good alternative to the current standard of visual tooth colour determination. The new module attains better results than the visual method and is comparable to the reference instrument.

Clinical relevance: Dentistry becomes increasingly digitalized and tooth colour determination devices have generally to be improved. Therefore, the investigation of a new digital device is important for future developments.

Keywords: Intra-oral scanner; Shade guide; Shade matching; Spectrophotometer; Tooth colour; Visual.