statement of problem: acrylic teeth of dentures are prone to discoloration due to frequent exposure to different colouring solutions in the oral environment. thus, in order to maintain their aesthetic appearance, they must possess high colour stability while exposed to colorant solutions. objectives: to compare the colour stability of three different brands of acrylic teeth following immersion ...

carotenoids are the main pigments of tomato, of which 93% is lycopene. lycopene has desirable physiological effects in human sush as cancer prevention. recent years, because of harmful side effects of synthetic colouring agents used in food products, employing of natural food colouring agents has become very important. in this research firstly, solvent extraction method was used for tomato caro...