Conservation of mass for a chemical that is transported (fig. 1) yields the advection-reaction-dispersion (ARD) equation:
Your dentist may also place a temporary crown while the permanent one is being made. Types of Dental Crowns. There are four different types of dental crowns. Ceramic â These are used for restoring front teeth, and are popular in this area for their ability to blend with your natural tooth color. The crown is made of a porcelain-based material.
But the latter can offer big advantages due to the way that it's constructed. 1  Crowns are fabricated in a dental laboratory, by a dental technician using copies (impressions) of your teeth. 2  Dental fillings, in comparison, are built during your dental appointment, within the confines of your mouth.