The electronic instruments for tooth color measurement available on the market have a different measuring geometry and different internal and external configuration. However, the color reproduction process with available dental porcelain requires them to provide uniform color information to the dental laboratory. This color information corresponds mainly with the codes of Vita classical shade tabs. Objectives: This study evaluated the reliability of the five most recent instruments for color measurement in dentistry, and the resemblance in the color values between them in correspondence to Vita. Methods: Two operators (OPI and OPII) assessed the color of the middle third of shades A1, A2, A3, A3.5 and A4 five times with ShadeEye (SE), ShadeScan (SS), Identa Color II (IC), Ikam (IK) and Easy Shade (ES) instrument. Intra-operator reliability from five measurements of five different colors per instrument was assessed by Cohen's Kappa, and the resemblance between the instruments in obtained color values was expressed in % of the scores that corresponded with the codes of the measured Vita shade guide tabs. Results:

	SE		%	IC		%	SS	%	IK		%	ES	%
OP I	0.785		77.5	0.537		5	1	90	0.901		100	1	100
OPII	0.805	82.5		0.901	12.5		0.899	85	0.646	87.5		1	100

Conclusions: ES, IK and SS showed the highest correspondence with Vita shade guide and SS the lowest. There seems to be more variation in Kappa's between the operators than between the instruments, probably due to the sensitivity of the handling procedure.