The Whitening Efficiency on Colored Teeth Author(s): Cristina-Stanca Molnar-Varlam, Milena Mkrtchyan, Adrian-Cristian Nicolau, Attila Titus Augustus SzolonAffiliation: University of Medicine and Pharmacy, Tîrgu Mureș, RomaniaDOI: 10.1515/jim-2017-0068