2International Organization for Standardization. Dental materials-de- termination of eolour stability. Geneva: International Organization for Standardization, 1985.
3Brewer JD, Wee A, Seghi R. Advances in color matching. Dent Clin North Am,2004,48(2) :341-358.
4Alma -Dozi, Cornelis J. Kleverlaan, Ahmed EI-Zohairy, et al. Per- formance of five commercially available tooth color-measuring de- vices. J Prosthodont, 2007,16(2) : 93-100.
7Corcodel N, Rammelsberg P, Moldovan O, et al. Effect of external light conditions during matching of tooth col- or: An intraindividual comparison[J]. Int J Prosthodont, 2009, 22 (1) : 75-77.
8Haddad HJ, Jakstat HA, Arnetzl G, et al. Does gender and experience influence shade matching quality[J]. J Dent, 2009, 37(Suppl 1):e40-e44.
9Corciolani G, Vichi A, Goracci C, et al. Colour corre- spondence of a ceramic system in two different shade guides[J]. J Dent, 2009, 37(2):98-101.
10Hassel A J, Koke U, Schmitter M, et al. Clinical effect of different shade guide systems on the tooth shades of ceramic-veneered restorations[J]. Int J Prosthodont, 2005, 18 (5) : 422-426.
