While new dentures are custom fit to your unique mouth shape, it is essential to remember that they are an artificial substitute for your natural teeth and will not feel or function equal to them. The denture may feel thick, bulky and foreign until your mouth and facial muscles have adapted to it. Some patients feel quite comfortable within a week, while others require a little longer. Time, patience and will power will be your greatest allies. Some adjustments may be required early on, but the feeling of a very full mouth will subside and in time your denture will feel quite natural.