Types of Dental Materials

Three major classes of materials: are alloys, ceramics, and polymers. Composite materials result when at least two of these three classes occur together in a material. Metals or alloys are bonded by metallic bonds into crystalline lattices, and these comprise all the metallic materials of restorative dentistry. In ceramics, ionic bonds form between metallic and nonmetallic elements into lattices; this arrangement is used by a wide variety of dental restorative materials. Polymers are organized into molecules via covalent bonds; molecules interact with each other to produce the diverse properties we see in common polymer restorative materials.

There are seven noble metals in the periodic table, but only three are common in dental casting alloys: gold (periodic table symbol Au), palladium (Pd), and platinum (Pt). Some metallurgists also consider silver (Ag) a noble metal, but because it tends to corrode in the oral environment, silver is not considered a noble metal in dentistry.

The American Dental Association (ADA) classifies alloys into three major groups: high-noble, noble, and predominantly base metal. Now the most commonly used alloys in dentistry are nickel-chromium, cobalt-chromium, titanium, and nickel-titanium alloys.