Introduction
Shade reproduction of natural teeth using restorative materials can be challenging
Visual determination of shade is subjective and influenced by multiple conditions, leading to inaccuracy
Technology and materials may improve automated shade-matching, leading to better outcomes

 

Objective
Assess the influence of various lighting conditions on the ability of a computer-based system to accurately identify tooth shades

Materials and Methods
Two shade tabs (A1 & C4) placed in a gingival matrix
Scanned under 3 conditions: Natural daylight, incandescent room light, and no illumination
60 total scans (20 per lighting condition)
Scanner color-calibrated before each scan
Measurements made in middle 3rd
Value and chroma of computer suggested shades were compared to the actual shade tabs

 

Discussion
Lower value (darker) shade tabs were matched with higher accuracy in all lighting conditions
Higher value (lighter) tabs were measured with more accuracy in sunlight/higher illumination
Scanner measured darker value shade tabs with most accuracy in low light conditions

Conclusions
Amount of illumination did effect scanner accuracy
Future studies to include larger sample sizes and wider range of shade values

 

References
Rutkunas V, Dirse J, Vytautas, B. Accuracy of an intraoral digital scanner in tooth color determination. J Prosthet Dent 2019 Jun 18. pii; S0022-3919(19)30074-5
Arakida T, Kanazawa M, Iwaki M, Suzuki T, Minakuchi S. Evaluating the influence of ambient light on scanning trueness, precision, and time of intra oral scanner. J Prosthodont Res. 2018 Jul;62(3):324-329
Lagouvardos PE, Fougia AG, Diamantopoulou SA, Polyzois GL. Repeatability and Interdevice reliability two portable color selection devices in matching and measuring tooth color. J Prosthet Dent 2009; 101:40-5.